Influenza viral infection in 2005-2006 in Samitivej Hospital.

OBJECTIVE: Set an alarm system for early detection of respiratory viral infection. MATERIAL AND METHOD: The authors prospectively investigated avian flu and SARS between March 2005 and April 2006. Specimens from a nasopharyngeal swab or bronchial washing were analyzed for influenza A, B, parainfluenza, adenovirus, respiratory syncytial virus and avian flu and SARS by using technique of PCR and immunofluorescence by the Department of Medical Sciences. RESULTS: Eighty-nine patients who were enrolled in the present study. Peak of the incidence was 43% on April 2005 and there was no incidence of the influenza from December 2005 till April 2006. This may be due to the mass campaign of influenza vaccination or seasonal variation. CONCLUSION: Vaccination remains the primary strategy for the prevention of influenza, and the broadened recommendations should lead to protection of a larger portion of the population.

Early containment of severe acute respiratory syndrome (SARS); experience from Bamrasnaradura Institute, Thailand.

BACKGROUND: On March 11, 2003, a World Health Organization (WHO) physician was admitted to Bamrasnaradura Institute, after alerting the world to the dangers of severe acute respiratory syndrome (SARS) in Vietnam and developing a fever himself. Specimens from the first day of his admission were among the first to demonstrate the novel coronavirus, by culture, reverse transcription-polymerase chain reaction (RT-PCR), and rising of specific antibody, but proper protective measures remained unknown. The authors instituted airborne, droplet and contact precautions from the time of admission, and reviewed the efficacy of these measures. MATERIAL AND METHOD: A specific unit was set up to care for the physician, beginning by roping off an isolated room and using a window fan to create negative pressure, and later by constructing a glass-walled antechamber, designated changing and decontamination areas, and adding high-efficiency particulate air (HEPA) filters. The use of personal protective equipment (PPE) was consistently enforced by nurse managers for all the staff and visitors, including a minimum of N95 respirators, goggles or face shields, double gowns, double gloves, full head and shoe covering, and full Powered Air Purifying Respirator (PAPR) for intubation. To assess the adherence to PPE and the possibility of transmission to exposed staff a structured questionnaire was administered and serum samples tested for SARS coronavirus by enzyme-linked immunosorbent assay (ELISA). Exposure was defined as presence on the SARS ward or contact with laboratory specimens, and close contact was presence in the patient's room. RESULTS: The WHO physician died from respiratory failure on day 19. 112 of 129 exposed staff completed questionnaires, and the 70 who entered the patient's room reported a mean of 42 minutes of exposure (range 6 minutes-23.5 hours). 100% reported consistent handwashing after exposure, 95% consistently used a fit-tested N95 or greater respirator, and 80% were fully compliant with strict institutional PPE protocol. No staff developed an illness consistent with SARS. Serum samples from 35 close contacts obtained after day 28 had a negative result for SARS coronavirus antibody. CONCLUSIONS: Hospitalization of one of the earliest SARS patients with documented coronavirus shedding provided multiple opportunities for spread to the hospital staff, but strict enforcement of conservative infection control recommendations throughout the hospitalization was associated with no transmission.

Isolation and identification of influenza virus strains circulating in Thailand in 2001.

Local influenza surveillance plays an important role in preparing for, and responding to, epidemics and pandemics. Between January and December 2001, the National Institute of Health of Thailand collected a total of 711 throat swab specimens from outpatients affected with acute respiratory symptoms from several centers throughout Thailand, of which 374 were virus-positive. Of these, 338 (90.4%) were positive for influenza virus by immunofluorescence testing. By hemagglutination-inhibition (HI) testing, 155 of the type A viruses were found to be subtype H1N1 strains closely related to A/New Caledonia/20/99, and 70 were subtype H3N2 A/Moscow/ 10/99-like viruses. For type B, the isolates were antigenically B/Sichuan/379/9-like by HI, although a number of the strains could be shown to be more closely related to earlier influenza B strains by genetic analysis. The strains circulating in Thailand were antigenically similar to strains isolated worldwide during the same period and to strains recommended by the WHO for inclusion in the vaccines for use in 2001-2002.