Effectiveness of Non-pharmaceutical Interventions in Controlling an Influenza A Outbreak in a School, Thailand, November 2007.

Non-pharmaceutical interventions are often recommended as a component of integrated control measures for pandemic influenza, but the effectiveness needs to be evaluated. An outbreak of influenza A (H1N1) in northern Thailand in November 2007 offered opportunity to evaluate these interventions. An investigation was conducted to describe the outbreak, evaluate effectiveness of non-pharmaceutical interventions and assess surge capacity of health agencies. A descriptive study was conducted by interviewing students and personnel in a school. We characterized transmission of the virus in this outbreak and explored effects of control measures. We identified that 44% of the students and teachers developed influenza during the 19-day outbreak. Non-pharmaceutical interventions including school closure, setting up a field hospital and community health education were implemented. These measures possibly limited the outbreak spreading to other schools nearby. Surveillance and preparedness plans could be strengthened to respond to pandemic and inter-pandemic influenza by using non-pharmaceutical interventions.

Incidence of respiratory pathogens in persons hospitalized with pneumonia in two provinces in Thailand.

Although pneumonia is a leading cause of death from infectious disease worldwide, comprehensive information about its causes and incidence in low- and middle-income countries is lacking. Active surveillance of hospitalized patients with pneumonia is ongoing in Thailand. Consenting patients are tested for seven bacterial and 14 viral respiratory pathogens by PCR and viral culture on nasopharyngeal swab specimens, serology on acute/convalescent sera, sputum smears and antigen detection tests on urine. Between September 2003 and December 2005, there were 1730 episodes of radiographically confirmed pneumonia (34·6% in children aged <5 years); 66 patients (3·8%) died. A recognized pathogen was identified in 42·5% of episodes. Respiratory syncytial virus (RSV) infection was associated with 16·7% of all pneumonias, 41·2% in children. The viral pathogen with the highest incidence in children aged <5 years was RSV (417·1/100,000 per year) and in persons aged ≥50 years, influenza virus A (38·8/100,000 per year). These data can help guide health policy towards effective prevention strategies.

A preliminary analysis of the epidemiology of influenza A(H1N1)v virus infection in Thailand from early outbreak data, June-July 2009.

As the influenza A(H1N1)v pandemic unfolds globally, it is vital to monitor closely for signals of change in the current patterns of transmission. We estimate the basic reproduction ratio for A(H1N1)v virus in Thailand and propose a method to keep track of the actual case count notwithstanding the exponential growth rate.

Monoclonal antibodies against respiratory syncytial virus for rapid detection and subgroup determination.

Thirty-one hybridomas producing monoclonal antibodies (MAbs) against structural proteins of RSV subgroup A (Long strain) and RSV subgroup B (Japanese wild strain) were produced and separated into three groups by their reactivities with RSV-A and RSV-B using IFA. Group I was specific to RSV-A, Group II was specific to RSV-B and group III was specific to both subgroups. Characterization of selected two MAbs from each group indicated that three MAbs recognized phosphoprotein (P) and the others recognized fusion protein (F). All of the selected MAbs were IgG1 and carried kappa light chain. These selected MAbs can be used to detect the presence of RSV from NPAs and classify them into two subgroups. The infection rates of RSV in Thai children are very low and most of them were RSV subgroup A.