A superspreading event involving a cluster of 14 coronavirus disease 2019 (COVID-19) infections from a family gathering in Hong Kong SAR (China)

@#Objective: An outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in Wuhan, China, in December 2019, with subsequent spread around the world. Hong Kong Special Administrative Region SAR (China) recorded its first confirmed cases on 23 January 2020. In this report, we describe a family cluster of 12 confirmed cases, with two additional confirmed cases from secondary transmission. Methods: We reported the epidemiological, clinical and laboratory findings of the family cluster, as well as the public health measures instituted. Results: All 12 confirmed COVID-19 cases were among the 19 attendees of a three-hour Chinese New Year family dinner consisting of hotpot and barbecue dishes. Environmental sampling of the gathering venue was negative. Two additional confirmed cases, who were co-workers of two confirmed cases, were later identified, indicating secondary transmission. Contact tracing, quarantine and environmental disinfection were instituted to contain further spread. Discussion: Our findings were highly suggestive of a superspreading event during the family gathering. The source was likely one of the cases during the pre-symptomatic phase. The event attested to the high infectivity of SARS-CoV-2 through human-to-human transmission from social activities and argued for the necessity of social distancing in curtailing the disease spread.

Surveillance and response of hepatitis B virus in Hong Kong Special Administrative Region, 1988–2014

The World Health Organization (WHO) Western Pacific Region with an estimated 160 million chronic hepatitis B virus (HBV) carriers in 2007 bears a significant burden of HBV-related mortality and morbidity. Most Member States in the region have an estimated chronic HBV infection proportion of more than 8% in their adult population, which is the highest worldwide. The WHO Regional Office for the Western Pacific published the first Regional Plan for Hepatitis B Control in January 2003. This plan is updated periodically with a consistent ultimate goal of achieving a chronic HBV infection rate of less than 1% in the region. Viral hepatitis is a statutorily notifiable disease in Hong Kong Special Administrative Region (SAR). The Central Notification Office of the Department of Health receives notifications with pre-defined case definitions. In July 2011, Hong Kong SAR was verified by the WHO Regional Office for the Western Pacific as having successfully achieved the goal of hepatitis B control. Liver cancer was the third leading cause of cancer death in Hong Kong SAR in 2012, and evidence showed that 75–80% of liver cancer cases were related to chronic HBV infection. This report reviews the surveillance data of HBV infections in Hong Kong SAR from 1988 to 2014 and discusses the responses and existing gaps to achieve the WHO goal in the local context.

Social network methodology for studying HIV epidemiology in men having sex with men

A self-administered network-based questionnaire survey was conducted on 91 HIV-positive Chinese men having sex with men [MSM]. Affiliation matrices were created to assess their networking pattern. The individuals' preferential use of venues for sex partnership before HIV infection has changed over three time periods of 1997-2000, 2001-2003 and 2004-2006. Over time, there was a parallel increase in network density [density scores from 0.26, through 0.36, to 0.53] and degree centrality [from a median score of 9, through 12, to 16], suggesting that connectivity of MSM was becoming higher through sexual networks. The overall practice of unprotected sex has, however, remained the same. The study demonstrated how the application of social network analysis could enrich the epidemiologic description of HIV infection in the population

Highly active antiretroviral therapy per se decreased mortality and morbidity of advanced human immunodeficiency virus disease in Hong Kong / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Morbidity and mortality of advanced human immunodeficiency virus infection (HIV) have declined in Western industrialized countries since the availability of highly active antiretroviral therapy (HAART). It is unclear if this has also happened in Hong Kong.</p><p><b>METHODS</b>We studied a retrospective cohort of patients with advanced HIV disease in Hong Kong, China. First, the mortality of advanced HIV disease per year was calculated for the decade 1993 to 2002, both annually and according to patient observation before and after 1997. Second, the event rates were estimated for the clinical end points of acquired immune deficiency syndrome (AIDS) and death. Univariate and multivariate analyses were then performed to identify associated factors.</p><p><b>RESULTS</b>The crude mortality of advanced HIV disease declined from 10.8-30.4 per 100 patients during 1993-1996, to 0.8-6.9 per 100 patients during 1997-2002. A rate ratio of 4.04 (95% CI, 2.52-6.47) was evident for those observed in 1993-1996, compared to those in 1997-2002. In a multivariate analysis where calendar period was adjusted, use of highly active antiretroviral therapy was associated with rate ratios of 0.13 (95% CI, 0.05-0.33) for death after AIDS, 0.08 (95% CI, 0.04-0.19) for AIDS after a CD4 cell count < 200/microl, and 0.21 (95% CI, 0.07-0.67) for death after CD4 cell count < 200/microl. In the same analysis, calendar period ceased to be a significant factor after adjustment for use of HAART.</p><p><b>CONCLUSIONS</b>The mortality and morbidity of advanced human immunodeficiency virus disease have declined in Hong Kong. This improved prognosis was attributable to the use of highly active antiretroviral therapy.</p>