Postpartum haemorrhage (PPH) is an important cause of maternal morbidity and mortality. Prevention is always better than treatment. In this issue of Hong Kong Medical Journal, Tse et al1 have compared the use of carbetocin with oxytocin infusion in reducing the need for additional uterotonics or procedures in women at increased risk for PPH undergoing Caesarean deliveries in a single Hospital Authority (HA) obstetric unit. Carbetocin was better than oxytocin infusion in reducing the requirement of additional uterotonics or procedures in pregnant women undergoing Caesarean sections with multiple pregnancies or major placenta praevia. The findings echo the first of the three recommendations from the territory-wide HA survey on massive PPH conducted in 2013.2 3

With the objectives of studying the characteristics of patients with massive primary PPH (defined as ≥1500 mL within the first 24 hours after delivery, which is the clinical indicator for obstetric performance in HA hospitals) and exploring areas for improvement in terms of prevention and treatment, a prospective study2 3 was conducted during the year 2013 in all the eight HA obstetric units using a pre-designed code sheet to record the details of all patients with massive primary PPH, including causes, risk factors, mode of delivery, interventions (uterotonic agents, second-line therapies and emergency hysterectomy), use of blood products, and maternal outcome.

Massive primary PPH occurred in 0.76% (n=277) of all deliveries (n=36 510) in HA obstetric units in 2013. The incidence was comparable to those reported in international literature. The majority occurred after Caesarean sections (84.1%). Uterine atony (37.5%), placenta praevia/accreta (49.9%), and uterine wound bleeding/tear during Caesarean section (24.2%) were the three most common causes. The median total blood loss was 2000 mL (range, 1500-20 000 mL). Coagulopathy occurred in 16.2% (n=45). A quarter (n=76, 27.4%) required intensive care or high dependent unit admission. There was no maternal mortality.

Second-line therapies (balloon tamponade, compression sutures and uterine artery/internal iliac artery embolisation or surgical ligation) were used in 40.1% (n=111). Emergency hysterectomy was required in 8.7% (n=24). A total of 1052 units of packed cells, 670 units of platelets, 568 units of fresh frozen plasma, and 200 units of cryoprecipitate were transfused.

The study identified three areas for improvement: (1) to increase the choice of uterotonic agents (carbetocin has been incorporated into HA Drug Formulary since January 2017, mainly for prevention of PPH in women at risk such as twin pregnancy, large fibroids, polyhydramnios, fetal macrosomia, and placenta praevia. In 2017, a total of 875 ampoules have been used in HA obstetric units, rising to 2500 ampoules in 2018, and 2865 ampoules in 2019); (2) to step up the use (and early use) of second-line therapies, and to watch out for failures from second-line therapy; (3) to reduce the incidence of placenta praevia/accreta through education and to improve its management at multiple care levels.

Carbetocin is a long-acting synthetic analogue of oxytocin indicated for prevention of uterine atony after Caesarean section. It is administered as a slow intravenous injection over 1 minute, with a rapid onset of uterine contraction within 2 minutes and lasting for several hours. It is also a heat-stable compound which does not require refrigeration. Latest Cochrane reviews showed that carbetocin may have some additional benefits compared with oxytocin and appears to be without an increase in adverse effects.4 The Carbetocin HAeMorrhage PreventION (CHAMPION) trial5 showed that carbetocin was non-inferior to oxytocin for the prevention of PPH after vaginal delivery as well.

The main disadvantage of using carbetocin in preventing PPH is its cost, making it much less cost-effective when compared with other uterotonic drugs.6 For local reference, carbetocin (single dose of 100 μg) costs HK$200, as compared with oxytocin (40 IU infusion, HK$32), syntometrine (single dose, HK$27), and misoprostol (800 μg, HK$7). As a result, when carbetocin was introduced into HA Drug Formulary in 2017, we have limited its use to those women with high-risk factors for PPH after Caesarean sections such as twin pregnancy, large fibroids, polyhydramnios, fetal macrosomia, and placenta praevia. For example, in 2018, only 2500/35 016 or 7.1% of all deliveries in HA had carbetocin for PPH prophylaxis when compared with around 90% of deliveries in private hospitals in Hong Kong. There is capacity to increase the use of carbetocin in HA by including more women with risk factors for PPH such as prolonged induction of labour (eg, oxytocin ≥12 hours), high parity (eg, ≥para 3), history of PPH, and others. These risk factors have not been included in Tse et al’s study.1 Carbetocin should not only be considered for Caesarean sections, but also for vaginal deliveries with same risk factors for PPH. Furthermore, the role of using carbetocin as treatment for PPH could be explored.

In addition to single-centre studies on the efficacy of a single drug or procedure on the prevention and treatment of PPH, further studies are required on the overall impact of the introduction of uterotonic drugs such as carbetocin; non-uterotonic drugs such as tranexamic acid; increasing use of second-line procedures7 such as balloon tamponade, compression sutures and uterine artery embolisation; and new patient blood management such as intravenous iron therapy, particularly in the current era of inadequate blood donation, being further aggravated by coronavirus disease 2019 (COVID-19).

Interestingly, with all the new modalities of prevention and treatment of PPH, the overall figures of primary PPH ≥500 mL (traditional definition), ≥1000 mL or ≥1500 mL (defined as massive PPH), including emergency hysterectomies for massive PPH, have not been improved in HA from 2013 to 2018 (Table).8 This phenomenon is different from what had been observed in a single obstetric unit over a different time period from 2006 to 2011.9 Fortunately, maternal mortality is still rare. Further studies are definitely indicated to look into the territory-wide HA data (using the Obstetrics Clinical Information System) to see whether the new modalities are not as effective as they are expected to be or our pregnant population is indeed becoming more and more high risk for PPH.

The author contributed to the manuscript, approved the final version for publication, and takes responsibility for its accuracy and integrity.

The author has disclosed no conflicts of interest.

1. Tse KY, Yu FN, Leung KY. Comparison of carbetocin and oxytocin infusions in reducing the requirement for additional uterotonics or procedures in women at increased risk for postpartum haemorrhage following Caesarean section. Hong Kong Med J 2020;26:382-9. Crossref

2. Lau KW, Chan LL, Lo TK, Lau WL, Leung WC; Hospital Authority COC Obstetrics and Gynaecology Quality Assurance Subcommittee. Territory-wide massive primary postpartum haemorrhage (PPH >1,500ml) survey in Hospital Authority obstetric units with recommendations and the way forward. Hospital Authority Convention 2017. Master Class 7.1. Available from: http://www3.ha.org.hk/haconvention/hac2017/ebook/HAC2017_abstract%20day%201.pdf. Accessed 29 Sep 2020.

3. Leung WC. An overview on massive postpartum haemorrhage in Hong Kong. The Hong Kong Medical Diary 2019;24(7):2-3.

4. Gallos ID, Papadopoulou A, Man R, et al. Uterotonic agents for preventing postpartum haemorrhage: a network meta-analysis. Cochrane Database Syst Rev 2018;(12):CD011689. Crossref

5. Widmer M, Piaggio G, Nguyen TM, et al. Heat-stable carbetocin versus oxytocin to prevent hemorrhage after vaginal birth. N Engl J Med 2018;379:743-52. Crossref

6. Pickering K, Gallos ID, Williams H, et al. Uterotonic drugs for the prevention of postpartum haemorrhage: a cost-effectiveness analysis. Pharmacoecon Open 2019;3:163-76. Crossref

7. Kellie FJ, Wandabwa JN, Mousa HA, Weeks AD. Mechanical and surgical interventions for treating primary postpartum haemorrhage. Cochrane Database Syst Rev 2020;(7):CD013663. Crossref

8. Hospital Authority Annual Obstetric Reports 2013 to 2018. Available from: https://www.ekg.org.hk/html/gateway/neweKG/newsp/h1-obs-gyn.jsp (internal access via eKG).

9. Chan LL, Lo TK, Lau WL, et al. Use of second-line therapies for management of massive primary postpartum hemorrhage. Int J Gynaecol Obstet 2013;122:238-43. Crossref

Pneumococcal infection, particularly invasive pneumococcal disease (IPD), has placed a substantial global burden of disease.1 In Hong Kong, from 2007 to 2015, the incidence rate of IPD increased from 1.7 to 2.9 per 100 000 population.2 It is one of the leading causes of disability and mortality, affecting individuals aged ≥65 years who are at higher risk of complications and premature death.3 The total number of local residents aged ≥65 years has already exceeded one million, accounting for approximately 16% of the whole population in Hong Kong.4 Due to the ageing population, the incidence of IPD is expected to rise continuously in the coming years.5

Evidence has shown that pneumococcal immunisation can effectively decrease the incidence and mortality of pneumococcal infection and IPD among older adults.6 7 An earlier large-scale cohort study demonstrated that immunisation was associated with a significant decrease in the risk of pneumococcal infection (hazard ratio=0.56) among patients aged >65 years.8 The pneumococcal immunisation can also lower the risks of both myocardial infarction9 and ischaemic stroke.10 Although pneumococcal immunisation is beneficial for IPD and cardiovascular disease control, the programme participation remained suboptimal worldwide.

The uptake rate of pneumococcal immunisation among older adults was only around 61% in the United States during 2013 to 2014.11 In England, the pneumococcal immunisation coverage among older adults was <70% during 2014 to 2015.12 In Hong Kong, only one-third of people aged ≥65 years received pneumococcal immunisation.13

The Hong Kong SAR Government has launched two pneumococcal immunisation programmes to eligible residents in October 2019: the Vaccination Subsidy Scheme and the Government Vaccination Programme.14 The Vaccination Subsidy Scheme provided a subsidy of HK$210 (~US$27) and HK$250 (~US$32) for influenza and pneumococcal immunisation, respectively, to eligible older individuals at enrolled private clinics as a measure to strengthen the preventive strategy for these diseases. It offers subsidies for both the 13-valent pneumococcal conjugate vaccine and the 23-valent polysaccharide pneumococcal vaccine. The Government Vaccination Programme provides eligible individuals with free pneumococcal immunisation at residential care homes for the elderly, designated centres of the Department of Health, and public clinics or hospitals managed by the Hospital Authority.14

In addition to pneumococcal vaccine, human papillomavirus (HPV) vaccination is currently available under the Hong Kong Childhood Immunisation Programme, wherein eligible female students may receive two doses of 9-valent HPV vaccine in their primary five and six school years.15 Other examples of Government-subsidised programmes for disease prevention include cervical cancer screening,16 colorectal cancer screening,17 and the Smoking Cessation Programme.18

In this issue of the Hong Kong Medical Journal, Man et al19 report an 8-year large-scale retrospective cohort study that included 792 adult patients in a major hospital. The authors found that the 30-day mortality rates were 11.5% overall and 24.5% in those patients with IPD. Among 170 patients admitted to the intensive care unit, the in-hospital mortality was 31.2%. The study results indicate that older age, the presence of chronic kidney disease, and disease severity are significantly associated with 30-day mortality. The study is limited by the absence of controls for potential confounders and its retrospective single-centre design; thus the generalisability to other settings may require cautious interpretation. This necessitates future evaluations to explore drug resistance patterns and capsular serotypes of pneumococcus. As claimed by the authors, this was the first and largest-scale investigation on pneumococcal disease in Hong Kong showing the significant burden posed by pneumococcal infection. The study exerts a significant impact on clinical care and resource planning for hospitals, given that up to 33% of IPD patients require intensive care unit care. In view of the public health impact, the role of pneumococcal vaccination in prevention should be enhanced.

Substantial evidence supports the effectiveness of preventive care and disease screening. A meta-analysis of 26 randomised controlled trials consisting of >73 000 individuals found that HPV immunisation can effectively protect adolescent girls and young females from cervical cancer.20 An international study conducted in eight countries by the World Health Organization found that the cumulative incidence of cervical cancer decreased by 94%, 93%, 91%, 84%, and 64% for a screening interval of 1 year, 2 years, 3 years, 5 years, and 10 years, respectively, among women who were screened before age 35 years.21 Screening is also beneficial for women aged 61 to 65 years, and is associated with a decreased risk of cervical cancer (hazard ratio=0.42), contributing to a reduction of approximately 3.3 cancer cases per 1000 women.22 Screening by faecal occult blood test and colonoscopy can effectively reduce the risk of colorectal cancer–related death by 33%23 and 68%24, respectively. Among patients who smoke ≥15 cigarettes daily, smoking reduction by 50% can significantly reduce the risk of lung cancer.25

The effect of physician intervention on disease prevention and screening is well documented in the literature. Participation rates of pneumococcal vaccination are associated with physician-delivered routine vaccine and promotion programmes.26 A study among Japanese primary care physicians found that patients who had pneumococcal vaccination were more likely to have received advice from physicians than those who did not receive such advice (80% vs 21%), and a strong association was shown between physician recommendation and patient participation in vaccination with an adjusted odds ratio of 8.50.27 A study in France demonstrated that patients who received recommendations from trusted family physicians were more likely to participate in HPV vaccination programme.28 In Hungary, physicians effectively motivated approximately 27% of women who initially refused to join cervical cancer screening programmes.29 Moreover, higher non-compliance rates were related to family physicians being foreign, at a younger age, and with a longer distance to the clinic from the patient’s home.30 A population-based telephone survey in Hong Kong found that people who were recommended by physicians were 23.5-fold more likely to have colorectal cancer screening uptake than those who did not.31 A recent study conducted in Canada using large administrative databases highlighted that the uptake of colorectal cancer tests by family physicians was significantly associated with greater uptake by their patients.32 Another study found that clinicians who specialised in respiratory diseases, thoracic surgery, and cardiology were more committed to encouraging patients to cease tobacco use.33

We believe that the study by Man et al19 acts as a call for more active participation by physicians in disease prevention and screening programmes, and appeal for your support. Physicians play an important role in both primary and secondary disease prevention for asymptomatic individuals, including promotion of lifestyle modifications, vaccination for infectious diseases, and screening for early-stage cancer lesions such as cervical cancer and colorectal cancer.

All authors contributed to the editorial, approved the final version for publication, and take responsibility for its accuracy and integrity.

The authors have disclosed no conflicts of interest.

1. Oishi K, Suga S. Pneumococcal infection: update [in Japanese]. Nihon Naika Gakkai Zasshi 2015;104:2301- 6. Crossref

2. Centre for Health Protection, Department of Health, Hong Kong SAR Government. Updated recommendations on the use of pneumococcal vaccines for high-risk individuals. 2019. Available from: https://www.chp.gov.hk/files/pdf/updated_recommendations_on_the_use_of_pneumococcal_vaccines_amended_120116_clean_2.pdf. Accessed 3 Sep 2020.

3. Shapiro ED. Prevention of pneumococcal infection with vaccines: an evolving story. JAMA 2012;307:847-9. Crossref

4. Census and Statistics Department, Hong Kong SAR Government. Population by age group and sex. 2019. Available from: https://www.censtatd.gov.hk/hkstat/sub/sp150.jsp?tableID=002&ID=0&productType=8. Accessed 3 Sep 2020.

5. Hung IF, Tantawichien T, Tsai YH, Patil S, Zotomayor R. Regional epidemiology of invasive pneumococcal disease in Asian adults: epidemiology, disease burden, serotype distribution, and antimicrobial resistance patterns and prevention. Int J Infect Dis 2013;17:e364-73. Crossref

6. Koivula I, Stén M, Leinonen M, Mäkelä PH. Clinical efficacy of pneumococcal vaccine in the elderly: a randomized, single-blind population-based trial. Am J Med 1997;103:281-90. Crossref

7. Domínguez À, Salleras L, Fedson DS, et al. Effectiveness of pneumococcal vaccination for elderly people in Catalonia, Spain: a case-control study. Clin Infect Dis 2005;40:1250-7. Crossref

8. Jackson LA, Neuzil KM, Yu O, et al. Effectiveness of pneumococcal polysaccharide vaccine in older adults. N Engl J Med 2003;348:1747-55. Crossref

9. Lamontagne F, Garant MP, Carvalho JC, Lanthier L, Smieja M, Pilon D. Pneumococcal vaccination and risk of myocardial infarction. CMAJ 2008;179:773-7. Crossref

10. Vila-Corcoles A, Ochoa-Gondar O, Rodriguez-Blanco T, et al. Clinical effectiveness of pneumococcal vaccination against acute myocardial infarction and stroke in people over 60 years: the CAPAMIS study, one-year follow-up. BMC Public Health 2012;12:222. Crossref

11. Williams WW, Lu PJ, O’Halloran A, et al. Surveillance of vaccination coverage among adult populations—United States, 2015. MMWR Morb Mortal Wkly Rep Surveill Summ 2017;66:1-28. Crossref

12. Public Health England. Pneumococcal polysaccharide vaccine (PPV) coverage report, England, April 2014 to March 2015. 2015. Available from: https://assetspublishingservicegovuk/government/uploads/system/uploads/attachment_data/file/448406/hpr2615_ppv.pdf. Accessed 5 Jul 2018.

13. Information Services Department, Hong Kong SAR Government. Pneumococcal vaccination for elderly persons. 18 Nov 2015. Available from: http://www.info.gov.hk/gia/general/201511/18/P201511180642.htm. Accessed 3 Jan 2018.

14. Centre for Health Protection, Department of Health, Hong Kong SAR Government. Government Vaccination Programme (GVP) 2019/20. Available from: https://www.chp.gov.hk/en/features/18630.html. Accessed 6 Jan 2020.

15. Department of Health, Hong Kong SAR Government. Child health—immunisation. Available from: https://www.fhs.gov.hk/english/main_ser/child_health/child_health_recommend.html. Accessed 27 Aug 2020.

16. Department of Health, Hong Kong SAR Government. Cervical Screening Programme. Available from: https://www.cervicalscreening.gov.hk/eindex.php. Accessed 27 Aug 2020.

17. Department of Health, Hong Kong SAR Government. Colorectal Cancer Screening Programme background. Available from: ttps://www.colonscreen.gov.hk/en/service/primary_care_doctor/programme_background.html. Accessed 27 Aug 2020.

18. Centre for Health Protection. Department of Health, Hong Kong SAR Government. Smoking. Available from: https://www.chp.gov.hk/en/healthtopics/content/25/8806.html. Accessed 27 Aug 2020.

19. Man MY, Shum HP, Yu JS, Wu A, Yan WW. Burden of pneumococcal disease: 8-year retrospective analysis from a single centre in Hong Kong. Hong Kong Med J 2020;26:372-81. Crossref

20. Arbyn M, Xu L, Simoens C, Martin-Hirsch PP: Prophylactic vaccination against human papillomaviruses to prevent cervical cancer and its precursors. Cochrane Database Syst Rev 2018;(5):CD009069. Crossref

21. Screening for squamous cervical cancer: duration of low risk after negative results of cervical cytology and its implication for screening policies. IARC Working Group on evaluation of cervical cancer screening programmes. Br Med J (Clin Res Ed) 1986;293:659-64. Crossref

22. Wang J, Andrae B, Sundström K, et al. Effectiveness of cervical screening after age 60 years according to screening history: Nationwide cohort study in Sweden. PLoS Med 2017;14:e1002414. Crossref

23. Hewitson P, Glasziou P, Watson E, Towler B, Irwig L. Cochrane systematic review of colorectal cancer screening using the fecal occult blood test (Hemoccult): An update. Am J Gastroenterol 2008;103:1541-9. Crossref

24. Nishihara R, Wu KN, Lochhead P, et al. Long-term colorectal-cancer incidence and mortality after lower endoscopy. New Engl J Med 2013;369:1095-105. Crossref

25. Godtfredsen NS, Prescott E, Osler M. Effect of smoking reduction on lung cancer risk. JAMA 2005;294:1505-10. Crossref

26. Santibanez TA, Zimmerman RK, Nowalk MP, Jewell IK, Bardella IJ. Physician attitudes and beliefs associated with patient pneumococcal polysaccharide vaccination status. Ann Fam Med 2004;2:41-8. Crossref

27. Higuchi M, Narumoto K, Goto T, Inoue M. Correlation between family physician’s direct advice and pneumococcal vaccination intention and behavior among the elderly in Japan: a cross-sectional study. BMC Fam Pract 2018;19:153. Crossref

28. Bish A, Yardley L, Nicoll A, Michie S. Factors associated with uptake of vaccination against pandemic influenza: a systematic review. Vaccine 2011;29:6472-84. Crossref

29. Gyulai A, Nagy A, Pataki V, Tonté D, Ádány R, Vokó Z. General practitioners can increase participation in cervical cancer screening—a model program in Hungary. BMC Fam Pract 2018;19:67. Crossref

30. Leinonen MK, Campbell S, Klungsøyr O, Lönnberg S, Hansen BT, Nygård M. Personal and provider level factors influence participation to cervical cancer screening: a retrospective register-based study of 1.3 million women in Norway. Prev Med 2017;94:31-9. Crossref

31. Sung JJ, Choi SY, Chan FK, Ching JY, Lau JT, Griffiths S. Obstacles to colorectal cancer screening in Chinese: a study based on the health belief model. Am J Gastroenterol 2008;103:974-81. Crossref

32. Litwin O, Sontrop JM, McArthur E, et al. Uptake of colorectal cancer screening by physicians is associated with greater uptake by their patients. Gastroenterology 2020;158:905-14. Crossref

33. Dülger S, Doğan C, Dikiş ÖŞ, et al. Analysis of the role of physicians in the cessation of cigarette smoking based on medical specialization. Clinics (Sao Paulo) 2018;73:e347. Crossref

Diabetes induces a substantial global burden of disease. The World Health Organization reported that the number of people with diabetes increased from 108 million in 1980 to 422 million in 2014, and the global prevalence of diabetes escalated from 4.7% in 1980 to 8.5% in 2014.1 The mortality rate due to complications of diabetes has been predicted to double between 2005 and 2030.1 It has been estimated that almost half of all patients with diabetes (49.7%) remain undiagnosed and unaware of their conditions.2 The American Diabetes Association recommends that people aged ≥45 years should be screened for diabetes or prediabetes, especially individuals who are overweight or obese.3 Patients with risk factors of diabetes should receive screening at an earlier age or at more frequent intervals. Laboratory-based criteria for diagnosing diabetes and prediabetes include fasting plasma glucose (FPG) level, glycated haemoglobin (HbA1c) level, and 75-g Oral Glucose Tolerance Test.3 In asymptomatic individuals, two abnormal glycaemic results are required to establish a diagnosis of diabetes.3 The United States Preventive Services Task Force recently updated recommendations and proposed screening from age 40 to 70 years at 3-year intervals, with all three tests being suitable as screening modalities.4 The Hong Kong Reference Framework for Diabetes Care for Adults in Primary Care Settings5 of the Primary Healthcare Office, the Hong Kong Government recommends that screening should begin at age 45 years, and should be conducted every 1 to 3 years, based on the presence of diabetes risk factors.5 Other authorities such as the Canadian Task Force on Preventive Health Care6 recommend screening based on HbA1c levels in high-risk individuals only, and those at low to moderate risk should complete a validated risk calculator such as FINDRISC7 or CANRISK8 to determine subsequent screening arrangements. Early diagnosis and proper treatment of type 2 diabetes mellitus reduces cardiovascular morbidity and mortality.9 Early detection also enables quality care to slow disease progression, prevent complications, and reduce the hospital care burden and healthcare costs.

In this issue of the Hong Kong Medical Journal, Chan and colleagues10 retrospectively studied 1566 patients who underwent total knee arthroplasties (TKAs) at an institution where universal diabetes screening was implemented. Among them, 46.6% received HbA1c screening during preoperative assessment of TKAs 2 to 3 months before the scheduled operation, and all patients with HbA1c level ≥7.5% were referred to an endocrinologist for optimisation of glycaemic control before the scheduled TKA. The other 53.4% who did not receive HbA1c screening acted as historical controls. The authors found that up to 38% of patients had undiagnosed prediabetes or diabetes as identified by the universal HbA1c screening programme. In addition, the incidence of prosthetic joint infections after surgery was significantly lower in patients who received HbA1c screening than in those who did not (0.2% vs 1.0%, P=0.027). These findings suggest that universal HbA1c screening seems justifiable for all patients before they undergo TKA. Although only 17 patients were referred to an endocrinologist, the lower rate of prosthetic joint infections among patients who had HbA1c screening may be attributed to the more meticulous perioperative care for those identified as having dysglycaemia. Whether HbA1c screening of dysglycaemia directly led to the lower rate of prosthetic joint infections remains uncertain, since the infection rate in the cohort before universal screening was introduced in March 2017 was similar for patients with diabetes or prediabetes and those without diabetes. The yield of screen-detected diabetes mellitus since 2017 was also low in this study, with most having prediabetes, most of whom were not referred to an endocrinologist for treatment. The major limitations of the study include its retrospective nature, single-centre design, lack of randomisation between groups, and the possibility of missing variables which could be confounders. Nevertheless, the findings contribute to a solid foundation where future prospective studies may offer more definitive practice-changing recommendations for clinical guidelines. Because diabetes is a silent condition and many people with diabetes remain undiagnosed, increased clinical awareness of the condition with screening using HbA1c level, particularly before major operations such as TKA, appears to be a justifiable approach.

Universal diabetes screening in the general population may also be worthwhile. However, several issues must be considered before formal implementation of population-based screening programmes. First, a systematic review and meta-analysis including 49 studies of screening tests and 50 intervention trials showed that HbA1c level has only average sensitivity of 0.49 (95% confidence interval [95% CI]=0.40-0.58) and specificity of 0.79 (95% CI=0.73-0.84),11 whereas FPG level is specific (0.94, 95% CI=0.92-0.96) but not sensitive (0.25, 95% CI=0.19-0.32). The diagnostic accuracy of HbA1c level for diabetes has also been challenged—in a cohort of 5764 adult patients without diagnosed diabetes, the sensitivity of HbA1c ≥6.5% was only 43.3% and 28.1% when FPG and 2-hour plasma glucose, respectively, were used as criteria.12 Although HbA1c level has advantages of greater convenience (not requiring fasting) and fewer day-to-day variations, HbA1c level may be affected by assay interference due to haemoglobinopathies and conditions altering red blood cell turnover such as recent blood loss. Second, diabetes screening fulfils the Wilson and Jungner criteria,13 but one of the most important determinants of programme success includes screening uptake and persistent adherence over time. Although a variety of cancer screening programmes, such as for colorectal and cervical cancer, have been implemented to the local population to address the rapidly rising burden on Hong Kong’s healthcare system, the uptake rate remains suboptimal. Conversely, few programmes have specifically targeted metabolic diseases such as diabetes. The Hong Kong Government’s effort to enhance the provision of primary care and encourage the uptake of preventive care among the elderly people through the Elderly Health Care Voucher Scheme was launched on 1 January 2009, and was regularised into a recurrent programme in 2014. Eligible residents aged ≥65 years are entitled to an annual voucher of HK$2000 to utilise private sector primary care preventive services. However, it has been shown that a majority of elderly people in Hong Kong thought the Scheme would encourage them to utilise acute services rather than preventive care or chronic disease management in the private sector.14

Before a universal diabetes screening programme for the general public can be successful, the perceptions of, attitudes to, enablers of, and barriers to diabetes screening should be explored among various stakeholders, including prospective programme participants, physicians practising in various sectors, and policy makers. These will identify pertinent variables that could enhance screening participation and programme design. Furthermore, the cost-effectiveness of screening using different test modalities starting at different age-groups should be evaluated. More work is needed, as effective community-based interventions are required to enhance screening uptake and improve the impact of diabetes screening through further evaluations to inform policy formulation and implementation.

All authors contributed to the editorial, approved the final version for publication, and take responsibility for its accuracy and integrity.

All authors have disclosed no conflicts of interest.

1. World Health Organization. Diabetes fact sheet. 2020. Available from: http://www.who.int/mediacentre/factsheets/fs312/en/. Accessed 12 Jul 2020.

2. Cho NH, Shaw JE, Karuranga S, et al. IDF Diabetes Atlas: Global estimates of diabetes prevalence for 2017 and projections for 2045. Diabetes Res Clin Pract 2018;138:271- 81. Crossref

3. American Diabetes Association. 2. Classification and diagnosis of diabetes: standards of medical care in diabetes—2020. Diabetes Care 2020;43(Suppl 1):S14-31. Crossref

4. Siu AL, US Preventive Services Task Force. Screening for abnormal blood glucose and type 2 diabetes mellitus: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2015;163:861-8. Crossref

5. Primary Healthcare Office. Food and Health Bureau, Hong Kong SAR Government. Hong Kong Reference Framework for Diabetes Care for Adults in Primary Care Settings. Available from: https://www.fhb.gov.hk/pho/english/health_professionals/professionals_diabetes_pdf.html. Accessed 12 Jul 2020.

6. Pottie K, Jaramillo A, Lewin G, et al. Recommendations on screening for type 2 diabetes in adults. CMAJ 2012;184:1687-96. Correction in: CMAJ 2012;184:1815. Crossref

7. Makrilakis K, Liatis S, Grammatikou S, et al. Validation of the Finnish diabetes risk score (FINDRISC) questionnaire for screening for undiagnosed type 2 diabetes, dysglycaemia and the metabolic syndrome in Greece. Diabetes Metab 2011;37:144-51. Crossref

8. Robinson CA, Agarwal G, Nerenberg K. Validating the CANRISK prognostic model for assessing diabetes risk in Canada’s multi-ethnic population. Chronic Dis Inj Can 2011;32:19-31.

9. Herman WH, Ye W, Griffin SJ, et al. Early detection and treatment of type 2 diabetes reduce cardiovascular morbidity and mortality: a simulation of the results of the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen-Detected Diabetes in Primary Care (ADDITION-Europe). Diabetes Care 2015;38:1449-55. Crossref

10. Chan VW, Chan PK, Woo YC, et al. Universal haemoglobin A1c screening reveals high prevalence of dysglycaemia in patients undergoing total knee arthroplasty. Hong Kong Med J 2020;26:304-10. Crossref

11. Barry E, Roberts S, Oke J, Vijayaraghavan S, Normansell R, Greenhalgh T. Efficacy and effectiveness of screen and treat policies in prevention of type 2 diabetes: systematic review and meta-analysis of screening tests and interventions. BMJ 2017;356:i6538. Crossref

12. Karnchanasorn R, Huang J, Ou HY, et al. Comparison of the current diagnostic criterion of HbA1c with fasting and 2-hour plasma glucose concentration. J Diabetes Res 2016;2016:6195494. Crossref

13. Wilson JM, Jungner YG, Organization WH. Principles and practice of mass screening for disease [in Spanish]. Bol Oficina Sanit Panam 1968;65:281-393.

14. Yam CH, Wong EL, Fung VL, Griffiths SM, Yeoh EK. What is the long term impact of voucher scheme on primary care? Findings from a repeated cross sectional study using propensity score matching. BMC Health Serv Res 2019;19:875. Crossref

Social media refers to internet-based tools that enable individuals and organisations to communicate and share ideas, personal messages, and images. Social media also provides a platform for collaboration among researchers and other like-minded individuals.1 These social networking activities have offered our community access to a very rich body of medical knowledge, in order to build both interpersonal and professional relationships. The global utilisation of social media has increased from 7% in 2005 to 65% in 2015,2 and has increasingly played a crucial role for the academic community to promote research, establish academic networks, and interact with the general public online. Many journals have now started to harness the influential capabilities of social media to share their articles to potential readers.3 Altmetrics, another metric of evaluating research impact, considers engagement of social media in computing impact.4 5

Is there evidence that social media works? In this digital era, the advancement in technology has allowed rapid communications without geographical restrictions. The use of social media and hashtags have been a norm for academics to have rapid exchange of information during medical conferences. It is not uncommon to have a ‘viral effect’ in the dissemination of medical information, where the degree of interaction and engagement among participants can be very overwhelming.6 Hawkins et al7 have analysed the impact of Twitter “tweet chat” sessions by evaluating the Twitter activity metadata tagged with the #JACR hashtag from tweet chat sessions promoted by the Journal of American College of Radiology. They found that the average monthly journal website visits and page views directly from Twitter increased 321% and 318%, respectively. In addition, the authors found that organising Twitter microblogging activities around disciplines of general interest to their target audience could potentially increase the reach and number of readers for medical journals. There is also evidence that citations to an article may be heavily reliant on visible exposure of the academic output.8 It has been argued that composing a high-quality article in journals could only confer 50% of the chance of being cited, whilst the other half rested on broad promotion and dissemination of the published articles.9 10 11 The objectives of employing social media for medical journals include enhancing their reach, timeliness, and efficiency of sharing medical literature. These objectives are shared by the Hong Kong Medical Journal (HKMJ), as pledged at the Journal’s inception in 1995 to provide “a useful source of medical information on advances in medical research and clinical practice”12 in a timely and efficient manner, and reiterated in February 2017.13

It is important that articles published in HKMJ reached and benefit as many readers as possible. Among the 10 most frequently cited HKMJ articles in the past years, seven were published in the Review Article or Medical Practice sections14 15 16 17 18 19 20; these papers likely represent more practice-changing content, and deserve to be disseminated to as wide an audience as possible. In order to expand the audience of HKMJ, from 1 June 2020 onwards, the Journal will formally launch a social media presence, overseen by the “HKMJ Expert Advisory Panel on Social Media”. Professor Jeremy Yuen-chun Teoh, an Editor of the HKMJ, has agreed to act as Panel Chair. We are also pleased and grateful that Dr Regina Sit, our Editor, and the three newest members of our Editorial Board, Dr Jason Yam, Dr Sherry Chan, and Dr Jason Cheung have also agreed to join the panel. These three individuals were awardees of the 2019 Best Original Research by Young Fellows, organised by the Hong Kong Academy of Medicine Foundation.

There are at least three social media platforms that we will leverage, including Facebook, Twitter, and LinkedIn, with each bringing different benefits: Facebook is currently the most widely used social media platform in Hong Kong21; Twitter allows fast and efficient communication with academics globally22 23; and LinkedIn is more widely used internationally for building professional networks of colleagues and collaborators. We believe these platforms will allow us to reach our targeted audience in an effective manner. In order to enhance readership, we will also start presenting key results of newly published studies in the form of visual abstracts; this has been shown to be very useful in enhancing engagement with healthcare professionals.24 This panel is also charged to ensure maintenance of patient confidentiality, provision of accurate interpretation of research findings, and ethical use of social media based on the guidelines published by professional organisations such as the American Medical Association.25 It is also an obligation to safeguard the quality of information being disseminated and to ensure professional and appropriate use of the social media platforms. We hope our readers will appreciate and utilise these initiatives, and share their thoughts and experience with us, by joining us on social media, or emailing the Editorial Office at hkmj@hkmj.org.hk.

1. Ventola CL. Social media and health care professionals: benefits, risks, and best practices. P T 2014;39:491-520.

2. Enago Academy. How social media promotion increase research citation? Available from: https://www.enago.com/academy/how-social-media-promotion-increase-research-citation/. Accessed 10 May 2020.

3. Lopez M, Chan TM, Thoma B, Arora VM, Trueger NS. The social media editor at medical journals: responsibilities, goals, barriers, and facilitators. Acad Med 2019;94:701-7. Crossref

4. Cann A, Dimitriou K, Hooley T. Social media: a guide for researchers. February 2011. Available from: https://www.researchgate.net/publication/261990960_Social_Media_A_Guide_for_Researchers. Accessed 10 May 2020.

5. Harris S. Making research connections with social media: advice for researchers. 25 March 2015. Available from: https://www.authoraid.info/en/resources/details/1240/. Accessed 10 May 2020.

6. Teoh JY, Mackenzie G, Smith M, et al. Understanding the composition of a successful tweet in urology. Eur Urol Focus 2020;6:450-7. Crossref

7. Hawkins CM, Hillman BJ, Carlos RC, Rawson JV, Haines R, Duszak R Jr. The impact of social media on readership of a peer-reviewed medical journal. J Am Coll Radiol 2014;11:1038-43. Crossref

8. Marashi SA, Hosseini-Nami SM, Alishah K, et al. Impact of Wikipedia on citation trends. EXCLI J 2013;12:15-9.

9. Ebrahim NA. Publication marketing tools “Enhancing Research Visibility and Improving Citations”. October 2012. Available from: https://www.researchgate.net/publication/232045669_Publication_Marketing_Tools_-_Enhancing_Research_Visibility_and_Improving_Citations. Accessed 10 May 2020.

10. Bong Y, Ebrahim NA. Increasing visibility and enhancing impact of research. Asia Research News 30 Apr 2017. Available from: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2959952. Accessed 10 May 2020.

11. Fagbule OF. Use of social media to enhance the impact of published papers. Ann Ib Postgrad Med 2018;16:1-2.

12. Lee JC, Yu YL. Inaugural editorial. Hong Kong Med J 1995;1:4.

13. Wong MC. Exerting an impact on clinical practice—upholding quality, visibility, and timeliness of publications. Hong Kong Med J 2017;23:4-5. Crossref

14. Leung AK, Hon KL, Leong KF, Sergi CM. Measles: a disease often forgotten but not gone. Hong Kong Med J 2018;24:512-20. Crossref

15. Kan HS, Chan PK, Chiu KY, et al. Non-surgical treatment of knee osteoarthritis. Hong Kong Med J 2019;25:127-33. Crossref

16. Hong YL, Yee CH, Tam YH, Wong JH, Lai PT, Ng CF. Management of complications of ketamine abuse: 10 years’ experience in Hong Kong. Hong Kong Med J 2018;24:175-81. Crossref

17. Tsang AC, Yeung RW, Tse MM, Lee R, Lui WM. Emergency thrombectomy for acute ischaemic stroke: current evidence, international guidelines, and local clinical practice. Hong Kong Med J 2018;24:73-80. Crossref

18. Wong PC, Chan YC, Law Y, Cheng SW. Percutaneous mechanical thrombectomy in the treatment of acute iliofemoral deep vein thrombosis: a systematic review. Hong Kong Med J 2019;25:48-57. Crossref

19. Yee A, Tsui NB, Chang YN, et al. Alzheimer’s disease: insights for risk evaluation and prevention in the Chinese population and the need for a comprehensive programme in Hong Kong/China. Hong Kong Med J 2018;24:492-500. Crossref

20. Chiu PK, Lee AW, See TY, Chan FH. Outcomes of a pharmacist-led medication review programme for hospitalised elderly patients. Hong Kong Med J 2018;24:98-106. Crossref

21. Penetration rate of leading social networks in Hong Kong as of 3rd quarter of 2019. Available from: https:// www.statista.com/statistics/412500/hk-social-network-penetration/. Accessed 10 May 2020.

22. Mohammadi E, Thelwall M, Kwasny M, Holmes KL. Academic information on Twitter: A user survey. PLoS One 2018;13:e0197265. Crossref

23. Gudaru K, Blanco LT, Castellani D, et al. Connecting the urological community: The #UroSoMe experience. J Endoluminal Endourol 2019;2:e20-9. Crossref

24. Chapman SJ, Grossman RC, FitzPatrick ME, Brady RR. Randomized controlled trial of plain English and visual abstracts for disseminating surgical research via social media. Br J Surg 2019:1611-6. Crossref

25. Shore R, Halsey J, Shah K, et al. Report of the AMA Council on Ethical and Judicial Affairs: Professionalism in the use of social media. J Clin Ethics 2011;22:165-72.

The 2019 coronavirus disease (COVID-19) is caused by severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2).1 The COVID-19 is primarily an acute viral respiratory disease which can manifest as acute upper or lower respiratory tract syndrome of varying severity, from asymptomatic virus shedding, rhinorrhoea, sore throat, conjunctivitis to cough, asymptomatic or silent hypoxia, chest discomfort, respiratory failure, or even multiorgan failure.1 2 Extrapulmonary manifestations include diarrhoea, lymphopenia, thrombocytopenia, deranged liver and renal function, rhabdomyolysis, anosmia, dysgeusia, meningoencephalitis, Guillain-Barre syndrome, Kawasaki disease like multisystem vasculitis, and thromboembolism.3 4 5 6 7 8 9 The outcome of COVID-19 is largely affected by older age and the presence of obesity and other underlying co-morbidities.10 11 The crude fatality varies widely for different geographical regions from 0.4% to 10%.12 13

Despite over 6 million COVID-19 cases and 360 000 deaths globally, Hong Kong has a total of about 1094 cases at the time of writing, which is one of the lowest per million population among developed regions. The painful experience of the SARS outbreak in 2003 sparked a large body of local animal surveillance, which showed that 39% of Chinese horseshoe bats could be harbouring bat SARS-related coronaviruses.14 Knowing that coronaviruses are prone to genetic mutations and recombination which produce new virus species, and the presence of a large reservoir of SARS-related coronaviruses in these horseshoe bats, together with the culture of eating exotic mammals in southern China, Hong Kong has anticipated and prepared for the re-emergence of SARS and other novel viruses from animals since 2007.15

Based on soft intelligence that an epidemic due to a suspected SARS-related coronavirus was looming in Wuhan on 31 December 2019, border thermal scanning and consensus reverse transcription polymerase chain reaction (RT-PCR) assays for unexplained pneumonia were started. The serious response level was activated by Centre for Health Protection on 4 January 2020. The University of Hong Kong–Shenzhen hospital has served as the sentinel for Hong Kong by identifying the first family cluster of COVID-19 who presented with symptoms after returning from Wuhan on 10 January 2020.1 This family cluster allowed us to preliminarily validate our in-house test for SARS-CoV-2 before commercial test kits were available. This family cluster showed that COVID-19 can be acquired from hospital, spreads very efficiently in the family setting with six out of seven members affected, and can have mild or asymptomatic manifestations.

Hong Kong is at high risk for COVID-19 dissemination. It is among the most densely populated regions globally with at least 200 000 people living in subdivided flats of 60 square feet or less. Furthermore, Hong Kong has a large elderly population with 1.27 million people over the age of 65 years who are susceptible to severe COVID-19. Hong Kong is also at high risk of travel-related case importation, as there are about 150 000 people crossing the Shenzhen–Hong Kong border and about 200 000 travelling via Hong Kong International Airport daily. Finally, Hong Kong has a cool dry winter which may favour virus transmission and its environmental stability. In view of the high number of mild or asymptomatic cases, the Hong Kong public was advised by medical colleagues from different medical specialties to practice universal masking in addition to good hand hygiene on 24 January 2020, despite some local dissenting views and opposite recommendation by the World Health Organization and overseas health authorities. The compliance of our community with face mask went up to 97% during the morning rush hour.16 It turned out that only 40% of our COVID-19 patients were locally acquired cases, and most local clusters of transmissions were related to mask-off activities. Thus, universal or community-wide masking, in addition to the standard border controls, case finding by extensive testing, mandatory admission for cases, rapid contact tracing and quarantine, and social distancing measures, may have given Hong Kong an edge in controlling the local spread of COVID-19. The high professional standard of Hong Kong healthcare workers, the excellent training in infection control, and the adequate supply of personal protective equipment have resulted in zero COVID-19–related mortality and morbidity among our hospital personnel 5 months after the pandemic began.

Epidemiological decisions must be made early enough to be effective, as transmission may have occurred 14 days before the case is detected. Thus, the first case from mainland China should immediately lead to land border control and quarantine of returnees. The first overseas case should lead to testing at the airport and quarantine of all overseas returnees. Increasing numbers of local clusters of untraceable sources should mandate more social distancing. But early case detection depends on extensive testing by RT-PCR especially for patients with mild symptoms. Extensive RT-PCR screening will continue to be one of the most important indicators guiding epidemiological decisions.

However, taking clinical specimens for RT-PCR by nasopharyngeal and throat swabbing of asymptomatic individuals induces discomfort and occasionally nasal bleeding. It may also induce coughing and sneezing, which endangers the healthcare workers. Mass screening would lead to a shortage of swabs. Hong Kong has circumvented these difficulties by patient self-collection of early morning posterior oropharyngeal (deep throat) saliva before breakfast and mouth rinsing.3 17 During sleep, the nasopharyngeal secretions of the upper respiratory tract will go posteriorly and pool around the oropharynx together with the bronchopulmonary secretions of the lower respiratory tract moved up by ciliary activity to almost the same level. Both upper and lower respiratory tract secretions are important for laboratory diagnosis because many patients have peripheral multifocal ground glass opacities on their lung computed tomography scan despite paucity of respiratory symptoms. If the patient can clear the throat by a coughing and gurgling manoeuvre at least 5 to 10 times into a sputum container with 2 mL of viral transport medium, the sensitivity would be similar if not better than the nasopharyngeal and throat swab. This is especially useful for daily viral load monitoring in antiviral treatment trial during which many patients resent the discomfort of taking daily nasopharyngeal swabs.18 With reliable collection of early morning posterior oropharyngeal saliva, the viral load of COVID-19 patients was found to peak early at the time of symptom onset or at presentation, or even before symptom onset during the period of quarantine.

Although mandatory admission of all RT-PCR positive patients, including those subclinical or mildly symptomatic, has led to a shortage of negative pressure single isolation rooms, this arrangement which is mandated by public health ordinance allows early recruitment of patients for antiviral therapy. Ex vivo lung tissue explant challenged by SARS-CoV-2 showed that the innate immune response of lung tissue by interferons and inflammatory cytokines/chemokines were markedly suppressed.19 Studies of the SARS outbreak in 2003 showed that interferonbeta can be synergistic with ribavirin, and a combination of lopinavir-ritonavir and ribavirin can markedly improve the outcome of SARS patients in terms of mortality and respiratory failure.20 21 A recently published multicentre, prospective, open-label, randomised, phase 2 trial showed that triple antiviral therapy (interferon beta-1b, lopinavir-ritonavir, and ribavirin) was safe and superior to lopinavir-ritonavir alone in alleviating symptoms and shortening the duration of viral shedding and hospital stay in adult patients with mild to moderate COVID-19.18 The early admission of patients for assessment, antiviral therapy, and respiratory support may explain our very low crude fatality rate of less than 0.4% in Hong Kong. Although remdesivir was also shown to reduce time to recovery in a large randomised control, this drug is unlikely to be readily available in Hong Kong as the production cannot meet the huge demand.22 Therefore we are collecting convalescent plasma from recovered patients with high serum neutralising antibody titre and use it as a salvage therapy for those who do not respond to antiviral treatment including interferon beta-1b or remdesivir.

Hong Kong cannot be complacent, because just one super-spreading event in Amoy Garden during the 2003 SARS outbreak led to an overloading and paralysis of our hospital service. Fortunately, such events have not happened yet for COVID-19. The emergency evacuations of residents from buildings with faulty sewage vent pipes were wakeup calls for our urgent attention to the maintenance of such sewage systems. The cluster of seven COVID-19 cases in Luk Chuen House at Lek Yuen Estate, living in six units on different floors, could herald a major super-spreading event and should not be treated simply as just one more community cluster. Extensive RT-PCR testing for at least one person per thousand population per day for any mild respiratory symptoms should be conducted in all 18 districts to minimise the evolvement of super-spreading events. The SARS-CoV-2 will continue to circulate during the summer and may cause an explosive outbreak in winter because our herd immunity is very low. Even the seroprevalence among Hong Kong returnees from Hubei is only 3.8%.23 A safe and effective vaccine is unlikely to become widely available for another 12 months or more. Thus, SARS-CoV-2 will likely become another seasonal respiratory coronavirus circulating in humans for many years to come. More research on the animal source of SARS-CoV-2, pathogenesis and immunology, and effective control measures are urgently needed.

All authors contributed to the concept or design of the study, acquisition and analysis of the data, drafting of the manuscript, and critical revision of the manuscript for important intellectual content. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.

All authors have disclosed no conflicts of interest.

The authors’ studies were partly supported by donations from Richard Yu and Carol Yu, May Tam Mak Mei Yin, the Shaw Foundation Hong Kong, Michael Seak-Kan Tong, Respiratory Viral Research Foundation, Hui Ming, Hui Hoy and Chow Sin Lan Charity Fund, Chan Yin Chuen Memorial Charitable Foundation, Marina Man-Wai Lee, the Hong Kong Hainan Commercial Association South China Microbiology Research Fund, the Jessie & George Ho Charitable Foundation, Perfect Shape Medical, and Kai Chong Tong; and by funding from the Consultancy Service for Enhancing Laboratory Surveillance of Emerging Infectious Diseases and Research Capability on Antimicrobial Resistance for the Department of Health of the Hong Kong Special Administrative Region Government; the Theme-Based Research Scheme (T11/707/15) of the Research Grants Council; Hong Kong Special Administrative Region; Sanming Project of Medicine in Shenzhen, China (no SZSM201911014); and the High Level-Hospital Program, Health Commission of Guangdong Province, China.

1. Chan JF, Yuan S, Kok KH, et al. A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster. Lancet 2020;395:514-23. Crossref

2. Hung IF, Cheng VC, Li X, et al. SARS-CoV-2 shedding and seroconversion among passengers quarantined after disembarking a cruise ship: a case series. Lancet Infect Dis. In press.

3. To KK, Tsang OT, Leung WS, et al. Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study. Lancet Infect Dis 2020;20:565-74. Crossref

4. Cheung KS, Hung IF, Chan PP, et al. Gastrointestinal manifestations of SARS-CoV-2 infection and virus load in fecal samples from the Hong Kong cohort and systematic review and meta-analysis. Gastroenterology 2020 Apr 3. Epub ahead of print. Crossref

5. Guan WJ, Ni ZY, Hu Y, et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl J Med 2020;382:1708-20. Crossref

6. Zhang Y, Xiao M, Zhang S, et al. Coagulopathy and antiphospholipid antibodies in patients with Covid-19. N Engl J Med 2020;382:e38. Crossref

7. Helms J, Kremer S, Merdji H, et al. Neurologic features in severe SARS-CoV-2 infection. N Engl J Med 2020 Apr 15. Epub ahead of print. Crossref

8. Tong JY, Wong A, Zhu D, Fastenberg JH, Tham T. The prevalence of olfactory and gustatory dysfunction in COVID-19 patients: A systematic review and metaanalysis. Otolaryngol Head Neck Surg 2020 May 5. Epub ahead of print. Crossref

9. Chung TW, Sridhar S, Zhang AJ, et al. Olfactory dysfunction in COVID-19 patients: observational cohort study and systematic review. Open Forum Infect Dis. In press.

10. Zhou F, Yu T, Du R, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet 2020;395:1054-62. Crossref

11. Kalligeros M, Shehadeh F, Mylona EK, et al. Association of obesity with disease severity among patients with COVID-19. Obesity (Silver Spring) 2020 Apr 30. Epub ahead of print. Crossref

12. Wu Z, McGoogan JM. Characteristics of and important lessons from the coronavirus disease 2019 (COVID-19) outbreak in China: Summary of a report of 72 314 cases from the Chinese Center for Disease Control and Prevention. JAMA 2020 Feb 24. Epub ahead of print. Crossref

13. Ferrari R, Maggioni AP, Tavazzi L, Rapezzi C. The battle against COVID-19: mortality in Italy. Eur Heart J 2020 Apr 30. Epub ahead of print. Crossref

14. Lau SK, Woo PC, Li KS, et al. Severe acute respiratory syndrome coronavirus-like virus in Chinese horseshoe bats. Proc Natl Acad Sci U S A 2005;102:14040-5. Crossref

15. Cheng VC, Lau SK, Woo PC, Yuen KY. Severe acute respiratory syndrome coronavirus as an agent of emerging and reemerging infection. Clin Microbiol Rev 2007;20:660-94. Crossref

16. Cheng VC, Wong SC, Chuang VW, et al. The role of community-wide wearing of face mask for control of coronavirus disease 2019 (COVID-19) epidemic due to SARS-CoV-2. J Infect 2020 Apr 23. Epub ahead of print. Crossref

17. To KK, Tsang OT, Chik-Yan Yip C, et al. Consistent detection of 2019 novel coronavirus in saliva. Clin Infect Dis 2020 Feb 12. Epub ahead of print. Crossref

18. Hung IF, Lung KC, Tso EY, et al. Triple combination of interferon beta-1b, lopinavir-ritonavir, and ribavirin in the treatment of patients admitted to hospital with COVID-19: an open-label, randomised, phase 2 trial. Lancet 2020;395:1695-704. Crossref

19. Chu H, Chan JF, Wang Y, et al. Comparative replication and immune activation profiles of SARS-CoV-2 and SARS-CoV in human lungs: an ex vivo study with implications for the pathogenesis of COVID-19. Clin Infect Dis 2020 Apr 9. Epub ahead of print. Crossref

20. Chu CM, Cheng VC, Hung IF, et al. Role of lopinavir/ritonavir in the treatment of SARS: initial virological and clinical findings. Thorax 2004;59:252-6. Crossref

21. Chen F, Chan KH, Jiang Y, et al. In vitro susceptibility of 10 clinical isolates of SARS coronavirus to selected antiviral compounds. J Clin Virol 2004;31:69-75. Crossref

22. Beigel JH, Tomashek KM, Dodd LE, et al. Remdesivir for the treatment of Covid-19—preliminary report. N Engl J Med 2020 May 22. Epub ahead of print.

23. To KK, Cheng VC, Cai JP, et al. Seroprevalence of SARSCoV- 2 in Hong Kong Special Administrative Region and our returnees evacuated from Hubei province of China: a multi-cohort study. Lancet Microbe. In press.