Comparison of predicted aquatic risks of pesticides used under different rice-farming strategies in the Mekong Delta, Vietnam.

This study evaluates the risks of pesticides applied in rice-fish and rice farming, with and without integrated pest management (IPM) strategies, to non-target aquatic organisms in two provinces of the Mekong Delta, Vietnam. Pesticide inventories and application patterns were collected from 120 Vietnamese farmers through interviews. Risks were assessed using (1) Pesticide RIsks in the Tropics to Man, Environment, and Trade (PRIMET), a first-tier model, which calculates predicted environmental concentrations (PECs) of pesticides in the rice field, based on the compound's physico-chemical properties and the application pattern, and then compares the PECs to safe concentrations based on literature data, and (2) species sensitivity distribution (SSD), a second-tier assessment model using species sensitivity distributions to calculate potentially affected fraction (PAF) of species based on the PECs from PRIMET. Our results show that several of the used insecticides pose a high risk to fish and arthropods and that the risks are higher among rice farmers than among rice-fish farmers. This study indicates that the PRIMET model in combination with SSDs offer suitable approaches to help farmers and plant protection staff to identify pesticides that may cause high risk to the environment and therefore should be substituted with safer alternatives.

Prevalence and predictors of cytomegalovirus retinitis in HIV-infected patients with low CD4 lymphocyte counts in Vietnam.

We describe the results of a study to determine the prevalence and characteristics of cytomegalovirus (CMV) retinitis among HIV-infected patients in Vietnam. We conducted a cross-sectional prospective study of patients with CD4 lymphocyte count ≤100 cells/mm(3)recruited from public HIV clinics. The diagnosis was made by a trained ophthalmologist using slit lamp biomicroscopy and corroborated on fundus photography. A total of 201 patients were screened. The median age was 32 years, 77% were men, median CD4 count was 47 cells/mm(3), and 62% were on antiretroviral treatment. Prevalence of CMV retinitis was 7% (14/201, 95% CI 4-11%). CMV retinitis was not associated with age, gender, injection drug use, CD4 count, WHO clinical stage, or antiretroviral treatment status. Blurring of vision and reduced visual acuity <20/40 were associated with CMV retinitis, but only 29% of patients with the diagnosis reported blurry vision and only 64% had abnormal vision. On multivariate analysis, the sole predictor for CMV retinitis was decreased visual acuity (OR 22.8,p < 0.001). In Ho Chi Minh City, CMV retinitis was found in 7% of HIV-infected patients with low CD4. HIV-infected patients with a CD4 count <100/mm(3)or who develop blurring of vision in Vietnam should be screened for CMV retinitis.