Investigation of botulism in free-range duck farming in the Mekong Delta, Vietnam.

Background: One of the most common diseases in free-range ducks in the Mekong Delta is botulism. Botulism is a poultry disease caused by botulinum exotoxin of Clostridium botulinum. Aim: To evaluate the prevalence of botulism in free-range ducks in the Mekong Delta and the risk of infection by determining the presence of C. botulinum in the farming environment. Methods: Research was carried out on 200 duck flocks with 187,050 individuals raised freely in the fields in the provinces of the Mekong Delta, including An Giang, Can Tho, Hau Giang, and Kien Giang. The ducks were diagnosed with botulism based on clinical symptoms. To demonstrate the presence of botulinum neurotoxins and identify serotype, samples of serum and/or gut were analyzed by mouse bioassay. Samples of soil (n = 600), water (n = 600), crabs (n = 216), and snails (n = 400) were taken from the grazing regions for C. botulinum analysis by PCR assay. Results: There were 1.19% (2,235/187,050) free-range ducks in the Mekong Delta positive for botulism. Clinical symptoms of botulism including limberneck, drooping eyelids-enlarged pupils, and leg paralysis were prevalent across free-range ducks, with the frequency of 87.92% (1,965/2,235), 90.07% (2,013/2,235), and 79.78% (1,783/2,235), respectively. The lesions of pulmonary edema-hemorrhage, hemorrhagic liver, and gas-producing intestines were common, accounting for 86.19% (362/420), 95.48% (401/420), and 92.14% (387/420), respectively. Botulin toxin type C was found in a considerable number of serum samples, accounting for 40.48% (51/126). Meanwhile, the percentage of serum samples containing botulin toxin types E and D was 28.57% (36/126) and 25.40% (32/126), respectively. Clostridium botulinum was detected in the farming environment specifically 17.5% (105/600) in soil, 19.67% (118/600) in water, 8.33% (18/216) in crabs, and 3.00% (12/400) in snails. Conclusion: The free-range ducks in the Mekong Delta were at high risk of botulism because of the latent presence of C. botulinum in the farming environment.

Immunological and viral determinants of dengue severity in hospitalized adults in Ha Noi, Viet Nam.

BACKGROUND: The relationships between the infecting dengue serotype, primary and secondary infection, viremia and dengue severity remain unclear. This cross-sectional study examined these interactions in adult patients hospitalized with dengue in Ha Noi. METHODS AND FINDINGS: 158 patients were enrolled between September 16 and November 11, 2008. Quantitative RT-PCR, serology and NS1 detection were used to confirm dengue infection, determine the serotype and plasma viral RNA concentration, and categorize infections as primary or secondary. 130 (82%) were laboratory confirmed. Serology was consistent with primary and secondary infection in 34% and 61%, respectively. The infecting serotype was DENV-1 in 42 (32%), DENV-2 in 39 (30%) and unknown in 49 (38%). Secondary infection was more common in DENV-2 infections (79%) compared to DENV-1 (36%, p<0.001). The proportion that developed dengue haemorrhagic fever (DHF) was 32% for secondary infection compared to 18% for primary infection (p = 0.14), and 26% for DENV-1 compared to 28% for DENV-2. The time until NS1 and plasma viral RNA were undetectable was shorter for DENV-2 compared to DENV-1 (p≤0.001) and plasma viral RNA concentration on day 5 was higher for DENV-1 (p = 0.03). Plasma viral RNA concentration was higher in secondary infection on day 5 of illness (p = 0.046). We didn't find an association between plasma viral RNA concentration and clinical severity. CONCLUSION: Dengue is emerging as a major public health problem in Ha Noi. DENV-1 and DENV-2 were the prevalent serotypes with similar numbers and clinical presentation. Secondary infection may be more common amongst DENV-2 than DENV-1 infections because DENV-2 infections resulted in lower plasma viral RNA concentrations and viral RNA concentrations were higher in secondary infection. The drivers of dengue emergence in northern Viet Nam need to be elucidated and public health measures instituted.

Acute febrile myalgia in Vietnam due to trichinellosis following the consumption of raw pork.

Trichinellosis outbreaks occur occasionally in Vietnam following the consumption of undercooked pork. Diagnosing trichinella can be problematic because fever and myalgia are nonspecific, and diagnosis may be delayed. We describe 5 Vietnamese patients in whom trichinellosis was diagnosed after several weeks of illness.

Ultrasonic investigation of exudation in Dengue hemorrhagic fever

69 patients with Deengue hemorrhagic fever (50 cases with shock and 19 cases without, aged 14-50) treated in the clinic institute of tropical diseases in the year 1998, were investigated by ultrasound just after admission from the 3rd to 7th day and by blood daily examination. The examination is related closely to the severity on clinic. Exudation rate in shock group account for 68.42% and in no shock group 24%. The early detection of exudation favorizes the diagnosis and treatment by humaral compensation in time to limit the progress to shock and death

Preliminary evaluation of effects of traditional drug “Fire Dragon” by augmentation of physical capacity and immunity in HIV/AIDS patients

20 persons with HIV/AIDS were treated by “Fire Dragon” formulation for 6 months in the Social Sponsored Center 5, Ha Tay Province (19 persons) and in the Institute of Clinical Tropical Disease (1 person) for 6 months. The patients were underwent 3 follow-up physical and laboratory examinations during treatment, using pre-defined form of medical record. “ Fire dragon” formulation