Facemasks and hand hygiene to prevent influenza transmission in households: a cluster randomized trial.

BACKGROUND: Few data are available about the effectiveness of nonpharmaceutical interventions for preventing influenza virus transmission. OBJECTIVE: To investigate whether hand hygiene and use of facemasks prevents household transmission of influenza. DESIGN: Cluster randomized, controlled trial. Randomization was computer generated; allocation was concealed from treating physicians and clinics and implemented by study nurses at the time of the initial household visit. Participants and personnel administering the interventions were not blinded to group assignment. (ClinicalTrials.gov registration number: NCT00425893) SETTING: Households in Hong Kong. PATIENTS: 407 people presenting to outpatient clinics with influenza-like illness who were positive for influenza A or B virus by rapid testing (index patients) and 794 household members (contacts) in 259 households. INTERVENTION: Lifestyle education (control) (134 households), hand hygiene (136 households), or surgical facemasks plus hand hygiene (137 households) for all household members. MEASUREMENTS: Influenza virus infection in contacts, as confirmed by reverse-transcription polymerase chain reaction (RT-PCR) or diagnosed clinically after 7 days. RESULTS: Sixty (8%) contacts in the 259 households had RT-PCR-confirmed influenza virus infection in the 7 days after intervention. Hand hygiene with or without facemasks seemed to reduce influenza transmission, but the differences compared with the control group were not significant. In 154 households in which interventions were implemented within 36 hours of symptom onset in the index patient, transmission of RT-PCR-confirmed infection seemed reduced, an effect attributable to fewer infections among participants using facemasks plus hand hygiene (adjusted odds ratio, 0.33 [95% CI, 0.13 to 0.87]). Adherence to interventions varied. LIMITATION: The delay from index patient symptom onset to intervention and variable adherence may have mitigated intervention effectiveness. CONCLUSION: Hand hygiene and facemasks seemed to prevent household transmission of influenza virus when implemented within 36 hours of index patient symptom onset. These findings suggest that nonpharmaceutical interventions are important for mitigation of pandemic and interpandemic influenza. PRIMARY FUNDING SOURCE: Centers for Disease Control and Prevention.

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.

Coronavirus-positive nasopharyngeal aspirate as predictor for severe acute respiratory syndrome mortality.

Severe acute respiratory syndrome (SARS) has caused a major epidemic worldwide. A novel coronavirus is deemed to be the causative agent. Early diagnosis can be made with reverse transcriptase-polymerase chain reaction (RT-PCR) of nasopharyngeal aspirate samples. We compared symptoms of 156 SARS-positive and 62 SARS-negative patients in Hong Kong; SARS was confirmed by RT-PCR. The RT-PCR-positive patients had significantly more shortness of breath, a lower lymphocyte count, and a lower lactate dehydrogenase level; they were also more likely to have bilateral and multifocal chest radiograph involvement, to be admitted to intensive care, to need mechanical ventilation, and to have higher mortality rates. By multivariate analysis, positive RT-PCR on nasopharyngeal aspirate samples was an independent predictor of death within 30 days.