Update on the Recommendations on Breast Cancer Screening by the Cancer Expert Working Group on Cancer Prevention and Screening

Breast cancer (BC) is the most common cancer among women in Hong Kong. The Food and Health Bureau commissioned The University of Hong Kong (HKU) to conduct the Hong Kong Breast Cancer Study (HKBCS) with the aim of identifying relevant risk factors for BC in Hong Kong and developing a locally validated BC risk assessment tool for Hong Kong Chinese women. After consideration of the most recent international and local scientific evidence including findings of the HKBCS, the Cancer Expert Working Group on Cancer Prevention and Screening (CEWG) has reviewed and updated its BC screening recommendations. Existing recommendations were preserved for women at high risk and slightly changed for women at moderate risk. The following major updates have been made concerning recommendations for other women in the general population: Women aged 44 to 69 with certain combinations of personalised risk factors (including presence of history of BC among first-degree relative, a prior diagnosis of benign breast disease, nulliparity and late age of first live birth, early age of menarche, high body mass index and physical inactivity) putting them at increased risk of BC are recommended to consider mammography screening every 2 years. They should discuss with their doctors on the potential benefits and harms before undergoing mammography screening. A risk assessment tool for local women (eg, one developed by HKU) is recommended to be used for estimating the risk of developing BC with regard to the personalised risk factors described above.

Emission strength of airborne pathogens during toilet flushing

The flushing of toilets generates contaminated aerosols, the transmission of which may cause the spread of disease, particularly in the immunocompromised or the elderly. This study investigated the emission strength of three types of airborne bacteria, namely Staphylococcus epidermidis, Escherichia coli, and Pseudomonas alcaligenes, during toilet flushing in a custom-built toilet under a controlled environment. Flushing was activated by a flushometer operated at two pressure levels, 400 kPa (high pressure [HP]) and 200 kPa (low pressure [LP]), and by a water cistern tank placed 95 cm (high tank [HT]) and 46 cm (low tank [LT]) above the toilet seat. The pathogens emitted by the first flush were calculated, with the correlations between airborne pathogen emissions and droplet concentration (HP, r=0.944, P<.001; LP, r=0.803, P<.001, HT, r=0.885, P<.05) and bacterial size (HP, r=-0.919, P<.001; LP, r=-0.936, P<.001; HT, r=-0.967, P<.05) in the different conditions then tested. The emission strength in the HP condition was statistically greater than that in the LP condition, whereas the cistern tank system produced less emissions than the flushometer system, and tank height was not found to be a sensitive parameter.

Burden, seasonal pattern and symptomatology of acute respiratory illnesses with different viral aetiologies in children presenting at outpatient clinics in Hong Kong

Respiratory viruses cause acute respiratory diseases with a broad and overlapping spectrum of symptoms. We examined the clinical symptoms and explored the patterns of various respiratory viral infections in children in Hong Kong. Among 2090 specimens collected from outpatient care (2007–2010), 1343 (64.3%) were positive for any virus by the xTAG assay, and 81 (3.9%) were positive for co-infection. The most frequently detected viruses among children aged 6–15 years were enterovirus/rhinovirus and influenza virus A, whereas most non-influenza viruses were more frequently detected in younger children. Higher body temperature was more common for illnesses associated with influenza viruses than for those associated with non-influenza viruses, but other symptoms were largely similar across all infections. The seasonality pattern varied among different viruses, with influenza virus A being the predominant virus detected in winter, and enterovirus/rhinovirus being more commonly detected than influenza virus A in the other three seasons, except for 2009.

Seroprevalence of antibody to pandemic influenza A (H1N1) 2009 among healthcare workers after the first wave in Hong Kong

During the first wave of an influenza pandemic prior to the availability of an effective vaccine, healthcare workers (HCWs) may be at particular risk of infection with the novel influenza strain. We conducted a cross-sectional study of the prevalence of antibody to pandemic influenza A (H1N1) 2009 (pH1N1) among HCWs in Hong Kong in February–March 2010 following the first pandemic wave. Sera collected from HCWs were tested for antibody to pH1N1 influenza virus by viral neutralisation (VN). We assessed factors associated with higher antibody titres, and we compared antibody titres in HCWs with those in a separate community study. In total we enrolled 703 HCWs. Among 599 HCWs who did not report receipt of pH1N1 vaccine, 12% had antibody titre ≥1:40 by VN. There were no significant differences in the age-specific proportions of unvaccinated HCWs with antibody titre ≥1:40 compared with the general community following the first wave of pH1N1. Under good adherence to infection control guidelines, potential occupational exposures in the hospital setting did not appear to be associated with any substantial excess risk of pH1N1 infection in HCWs. Most HCWs had low antibody titres following the first pandemic wave.