Epidemiology of Cases of H5N1 Virus Infection in Indonesia, July 2005?June 2006

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Epidemiology of Cases of H5N1 Virus Infection in Indonesia, July 2005?June 2006
JID 2007:196 (15 August)

Endang R. Sedyaningsih,1 Siti Isfandari,1 Vivi Setiawaty,1 Lutfah Rifati,1 Syahrial Harun,1 Wilfred Purba,2 Sholah Imari,2 Sardikin Giriputra,3 Patrick J. Blair,4 Shannon D. Putnam,4 Timothy M. Uyeki,5 and Triono Soendoro1

1National Institute of Health Research and Development and 2Directorate General of Disease Control and Environmental Health, Ministry of Health, 3Infectious Disease Hospital Sulianti Saroso, and 4US Naval Medical Research Unit No. 2, Jakarta, Indonesia; 5Centers for Disease Control and Prevention, Atlanta Georgia


Background. Highly pathogenic avian influenza A (H5N1) virus was detected in domestic poultry in Indonesia beginning in 2003 and is now widespread among backyard poultry flocks in many provinces. The first human case of H5N1 virus infection in Indonesia was identified in July 2005.

Methods. Respiratory specimens were collected from persons with suspected H5N1 virus infection and were tested by reverse-transcriptase polymerase chain reaction and viral culture. Serum samples were tested by a modified hemagglutinin inhibition antibody and/or microneutralization assay. Epidemiological, laboratory, and clinical data were collected through interviews and medical records review. Close contacts of persons with confirmed H5N1 virus infection were investigated.

Results. From July 2005 through June 2006, 54 cases of H5N1 virus infection were identified, with a case fatality proportion of 76%. The median age was 18.5 years, and 57.4% of patients were male. More than one third of cases occurred in 7 clusters of blood-related family members. Seventy-six percent of cases were associated with poultry contact, and the source of H5N1 virus infection was not identified in 24% of cases.

Conclusions. Sporadic and family clusters of cases of H5N1 virus infection, with a high case-fatality proportion, occurred throughout Indonesia during 2005?2006. Extensive efforts are needed to reduce human contact with sick and dead poultry to prevent additional cases of H5N1 virus infection.

http://www.journals.uchicago.edu/JID/journal/issues/v196n4/37962/37962.web.pdf [<< entire article avaiable here]

 

[Theresa42]

Re: Epidemiology of Cases of H5N1 Virus Infection in Indonesia, July 2005?June 2006

From the Discussion:

There are a number of limitations to our findings. It is very likely that the number of confirmed cases of H5N1 virus infection identified during 2005?2006 underestimated the true incidence of H5N1 virus infection that occurred in Indonesia. Specimens were not available for H5N1 testing from a few fatal cases that were classified as probable cases. Other case patients might not have been identified because they did not seek medical attention or received a diagnosis of other diseases; did not meet the surveillance suspect case definition if they had asymptomatic infection or mild illness, as noted previously; or had atypical symptoms [26]. In addition, it is possible that some H5N1 virus infections were not identified by RT-PCR because of the initial use of clade 1 virus primers and probes before clade 2 subclade 1 primers and probes were available or because of suboptimal respiratory specimens. Serum collected >21 days after exposure to poultry or to case patients was not available for all suspected cases and contacts, and serological testing may have missed some persons with milder or asymptomatic infection who had not developed detectable H5N1 antibodies.