The lower serum immunoglobulin G2 level in severe cases than in mild cases of pandemic H1N1 2009 influenza is associated with cytokine dysregulation.

The majority of patients with pandemic influenza H1N1 2009 had mild illness, but some, including those with no risk factors for severe disease, may succumb to this infection. Besides viral factors such as the D222/225G substitution of the hemagglutinin, host factors such as IgG2 subclass deficiency recently was reported to be associated with severe disease in a cohort of Australian patients besides other known risk factors, including underlying chronic illness, extremes of age, and pregnancy. We conducted a case-control study of 38 Asian patients with respiratory failure due to severe pandemic influenza and compared the results to those for 36 mild cases. None had selective IgG2 deficiency, but the level of IgG2 subclass was significantly lower in the severe cases (3.55 g/liter versus 4.75 g/liter; P = 0.002), whereas the levels of IgG1, IgG3, and IgG4 were not significantly different from those of the mild cases. Previous studies suggested that some IgHG2 and FcγRIIa genotypes were associated with IgG2 deficiency. The allelic frequency of the IgHG2 genotypes in our severe cases was not correlated with their levels of IgG2, while that of FcγRIIa was not significantly different from that of the general Han Chinese population (P = 0.216). Only the overall cytokine/chemokine profile (P = 0.029) and serum globulin level (P = 0.005) were found to be independently associated with the IgG2 level by multivariate analysis. The lower IgG2 level in our severe group might be related to cytokine dysregulation rather than being a significant risk factor for severe pandemic influenza. The importance of this finding for therapeutic intervention will require further studies of larger cohorts of patients.

The lessons of SARS in Hong Kong.

Severe acute respiratory syndrome (SARS) is a novel coronavirus infection which broke out in Hong Kong in March 2003. Princess Margaret Hospital was designated to manage this new, mysterious and serious disease. Healthcare workers had to work under extremely stressful and often risky conditions to care for patients. Despite manpower and equipment reinforcements, staff infection occurred as a result of bodily exhaustion, working in an unfamiliar environment and lapses in infection control. Patients suffered even more, not only due to physical discomfort, but also because of the fear of isolation and death away from family and friends. Health authorities learnt their lessons in the outbreak and formulated emergency plans for future infectious disease epidemics. The healthcare infrastructure has been examined and upgraded with regard to intensive care capacity, infection control measures, professional training, manpower deployment, staff facilities, and stockpiling of drugs and personal protective equipment.

Low prevalence of subclinical severe acute respiratory syndrome-associated coronavirus infection among hospital healthcare workers in Hong Kong.

We recruited 688 hospital healthcare workers who cared for patients with severe acute respiratory syndrome (SARS) and did not develop the disease in the Hong Kong outbreak in 2003. A questionnaire survey was conducted and serum samples were collected for SARS-associated coronavirus (SARS-CoV) antibody. The high-risk procedures performed and the types of unprotected exposures were recorded for analysis. Only 1 asymptomatic nurse had positive serological test. The result demonstrates the low rate of subclinical SARS-CoV infection in hospital healthcare workers and that the infection control practice against SARS in Hong Kong's hospitals during the outbreak was highly effective.

Severe acute respiratory syndrome-related diarrhea.

BACKGROUND: Severe acute respiratory syndrome (SARS) is an emerging infectious disease and diarrhea has been reported in up to 76% of cases. The purpose of the present paper was to carry out a retrospective study of the clinical and demographic data of SARS patients with diarrhea in Princess Margaret Hospital. METHODS: From 1 to 31 March 2003, hospital records from 240 patients with confirmed SARS were studied. Patients with watery stool of >/=3 times/day for at least 3 consecutive days were defined as the diarrhea group. Clinical and demographic data were compared between the diarrhea and non-diarrhea groups. Chest X-ray (CXR) scores during the peak of diarrhea period were recorded by a respiratory physician. These CXR scores were correlated with the peak frequency of diarrhea by Spearman's correlation coefficient. RESULTS: Diarrhea occurred in 20.4% of patients after admission. Female patients were predominant with a female to male ratio of 6:1 (P < 0.001) and 69.4% of patients were living in Amoy Gardens Estate (P = 0.01). The proportions of patients requiring ventilatory care and mortality in the diarrhea group were 8.2% and 2%, respectively, which were significantly lower than those in the non-diarrhea group (27.6% and 16.2%, P < 0.005). The CXR scores during the peak of diarrhea were not correlated with the maximum frequency of diarrhea (r = -0.09, P = 0.5). CONCLUSIONS: A total of 20.4% of SARS patients had the complication of diarrhea after hospital admission. Both female sex and being a resident of Amoy Gardens Estate were associated with diarrhea. The diarrhea group had a better prognosis.

Prevalence of irritable bowel syndrome in Hong Kong.

BACKGROUND AND AIMS: As part of a public education program, the Hong Kong Society of Gastrointestinal Motility studied the prevalence of irritable bowel syndrome (IBS) in the community, which was based on the recently published Rome II criteria. The distribution of diarrhea or constipation-predominant IBS subtypes, the prevalence of bowel symptoms and the predictors of health-care seeking were also studied. METHODS: Among 1797 randomly selected respondents, 1000 successful telephone interviews (56%) were conducted from August 2000 to December 2000, using a validated questionnaire in Chinese that looked into demographic data and various bowel symptoms during the past year. RESULTS: The 12-month prevalence of IBS as defined by the Rome II criteria in Hong Kong was 6.6%. The female to male ratio was 1.3:1, but this ratio was the same in the control group. The distribution of IBS patients into diarrhea predominant, constipation predominant, and non-specific subtypes was 27, 17 and 56%, respectively. The predominant symptom in the IBS group was pain (54.5%), followed by urgency (15%), abdominal distension (15%) and diarrhea (11%). Forty-seven percent of IBS patients sought medical attention and only 21% of them knew that they had IBS. Moderate to severe pain severity (odds ratio 3.7, 95% CI 1.02-13) and mucus in stool (odds ratio 3.57, 95% CI 1.18-10.7) were associated with health-care seeking in univariate analysis. The prevalence of bowel symptoms such as urgency, straining, feeling of incomplete defecation, mucus in stool and abdominal distension ranged from 11 to 41%. CONCLUSION: The prevalence of IBS in Hong Kong was 6.6%, and the female to male ratio was similar to the control group. The majority was of non-specific IBS subtype. Gross underdiagnosis (21%) by Western practitioners was noted.