Bird flu or avian flu, caused by H5N1 virus, is a new emerging infectious disease. There has been worldwide avian influenza infections in poultry since 1997. Recently, H5N1 caused severe disease with high mortality in humans in Vietnam and Thailand.1 Most infected cases usually developed progressive pneumonia with acute respiratory distress syndrome and consequently died. Atypical presentations of patients with bird flu were also noted. de Jong et al recently reported a fatal bird flu infected case in Vietnam with a presentation of diarrhoea, without respiratory symptoms.2
I performed a mini-study in order to document the magnitude of diarrhoeal presentation among reported Thai patients and the correlation with outcome. A literature review on papers concerning human bird flu in Thailand was performed using databases of published works cited in Index Medicus and the Science Citation Index. I also reviewed published works in all 256 local Thai journals, which are not included in the international citation index, for reports of human bird flu infection in Thailand. Studies that contained incomplete data were excluded from further analysis.
Six reports3–8 of 12 Thai patients with a confirmed diagnosis of bird flu were found. Of 12 infected cases, respiratory symptoms were seen in all cases and diarrhoea was detected at presentation in five cases (41.7 %) Considering the five diarrhoeal cases, acute respiratory distress syndrome (ARDS) was detected in four cases and there were three deaths. Concerning the seven non-diarrhoeal cases, ARDS was detected in five cases and there were five fatalities. There was no significant correlation between presentation of diarrhoea and development of ARDS (p>0.05) or fatality (p>0.05) but there was a significant correlation between the development of ARDS and fatality (p = 0.001).
There are some reports of diarrhoea in severe bird flu infection.2 Poovorawan recently proposed that diarrhoea was an important presentation of bird flu and could imply a poor prognosis.9 Here, I attempted to assess the magnitude of diarrhoea among Thai infected cases and its correlation with infection outcome. According to this study, the prevalence of diarrhoeal presentation was high, similar to a recent study in Vietnam (approximately 70 %).10 I therefore conclude that diarrhoeal presentation had a poor correlation with outcome of infection among our subjects.
Conflict of interest: None declared.
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