Risk factors for human avian influenza (A/H5N1) infection in Vietnam 2004

We conducted a matched case-control study with 28 laboratory-confirmed cases of influenza A/H5N1 (by RT-PCR assay) and 106 controls in Vietnam in the year 2004 (case to control ratio is 1:4). Matching criteria includes sex, age (the difference is less than 2 year) and location of living. Main results are as follow: (1) Two poultry-related risk factors of human avian influenza A/H5N1 are direct handling of ill/dead poultry, and having ill/dead poultry in household. (2) Unavaillable indoor water-tap in household is signifficantly associated with human influenza A/H5N1. This is an suggestion to the role of hygiene and invironment-related factors, but the mechanism is still not clear. (3) Exposure to healthy poultry, domestic animals and patients with acute respiratory infections seems not to be a risk factor for avian influenza infection in the year 2004. Further studies with integrated designs are needed to describe mode(s) of transmission and identify sources of infection.

Epidemiological characteristics of viral acute encephalitis in some Northern areas, 2003-2004

Morbidity and mortality from acute encephalitis in Vietnam have remained very high, especially in the Northern region. Except for Japanese Encephalitis (JE), the acute viral encephalitis (VE) was not studied as needed. Study was conducted in 374 hospitalized patients aged under 15 with diagnosis of VE in 2003-2004. The results showed that the male to female ratio was 2.3:1. The morbidity and mortality in all ages were not different, but the mortality rate was higher in group of under 10. More than 75% of morbidity occured from April to July.

Epidemiological characteristics of the epidemic of human H5N1 avian influenza in Northern Vietnam 2003-2004

At the end of 2003 and early 2004, an epidemic of avian influenza with 10 cases and 7 deaths occurred in the North of Vietnam, a subtype H5N1 (A/H5N1) has been identified. The prevalence of total infection with epidemic syndrome in the whole area at the same time was 0.1%, the prevalence infected cases of death was very high (70%). The epidemic was widely distributed in 7 provinces and the highest number of cases was observed in the forth week by the onset of the first case. Sick hens were the evidence of causes. There was not direct infection from human to human. However, there were two case-clusters that happened in the same family, this may be a suggestion of biological and familial factors associated with the susceptibility to the causal virus A/H5N1

Some remarks on epidemiological characteristics and pathogens of an acute diarrhea outbreak

The study showed some remarks on epidemiological characteristics and pathogens of an acute diarrhea outbreak. The outbreak including 25 patients without death occurred on some communes in Hanoi on May, 2004. V. cholerae 01 was isolated from 13/25 patients. Although it was not clear about the source of infection, the initial proof on bio-molecule showed that the outbreak occurred strain might have the same source with V. cholerae O1 isolated in 2000, 2002 and 2003 around Vietnam. In addition, the study also showed some comments and experiences on preventing outbreak

Masures for SARS control and prevention

On February and March 2003, SARS broke into Vietnam. To prevent the outbreak, it was necessary to supervise closely and regularly all acute pulmonary infectious patients, to detect patients based on diagnosis criteria. SARS outbreak is very dangerous, and it requires emergency epidemic reports, isolated areas of especial treatments for patients. Individuals exposed to SARS patients and people in the community need to be guided and encouraged for use preventive methods. Along with preventive individualization, it’s necessary to have preventive methods for community, especially for high-risk people of SARS infection