Background: Recently, microplate almar blue assay has been used commonly in detecting gen related to tuberculosis drug resistance, which provides results after 5-7 days with lower cost compared to traditional methods. Objective: To evaluate the application of microplate almar blue assay for rapid detection of drug resistance of M. tuberculosis strains. Subject and Method: A microplate-based assay which uses Alamar blue reagent - an oxidation reduction dye (MABA), was used for the determination of the anti-tuberculosis drug (isoniazid-INH, rifampicine-RIF, streptomycine-STR and ethabuton=EMB) resistance of 96 M. tuberculosis strains isolated from Vietnamese patients in comparison to those obtained by conversional method. Result: MABA showed to have high sensitivity and specificity in testing the sensitivity to individual anti-tuberculosis drugs (from 82.4% for STR to 93.3% for - INH and from 82.5% for EMB to 98.4% for STR; respectively), as well as for the multi-drug resistant M.tuberculosis (86.4% of sensitivity), highly correlated with the result determined by proportion method. Conclusion: MABA reveals the advantage in shortening test time, in simple performance and lower cost compared with the conversional culture based methods.
Microplate almar blue assay ; M. tuberculosis ; drug resistance

Objective: To establish a surveillance in Dong Thap, at the border with Cambodia by assessing the presence of DENV serotypes and CHIKV among patients hospitalized at Dong Thap general hospital. Methods: Cross-sectional descriptive analysis was conducted on a cohort of 131 patients hospitalized with acute fever and symptoms compatible with dengue or chikungunya. The study was conducted from January 2012 to February 2013. The full clinical picture was established as well as serological and molecular detection. Serological analysis was sequentially performed on blood samples collected on admission and an average of seven days after admission. The detection of IgM antibody to DENV was performed by IgM capture ELISA and the detection of DENV and CHIKV RNA was done by reverse-transcription multiplex PCR. Results: 101 patients out of 131 (77%) were confirmed with dengue. All four dengue serotypes were detected with a predominance of DENV2 and DENV4. No chikungunya infection was detected although reported in neighboring Cambodia. A differential efficiency of serological dengue detection was observed. Efficiency was 29% upon admission and 53% after seven days on the same patients. 30 patients out of 131 (23%) were negative with both DENV and CHIKV. Conclusions: Dengue is at risk of being underestimated and chikungunya is not systematically detected. Changes in detection and surveillance procedures are therefore discussed to increase efficiency of dengue detection and continue the monitoring the emergence of CHIKV in Dong Thap province and in Vietnam.

Objective: To record the human cases of dengue fever (DF) and investigate the Aedes mosquito species circulating during the Hanoi 2011 DF epidemics. Methods: 24 different outbreak points were recorded in 8 districts between August and December 2011. Results: 140 patients were hospitalized following dengue diagnostic with a predominance of males (59.3%) and the 15-34 age class. Only DENV-1 (11.27%) and DENV-2 (88.73%) serotypes were detected in human samples. Mosquito sampling performed in and around patients households revealed the predominance of Aedes aegypti (A. aegypti) (95.15%) versus Aedes albopictus (4.85%). Conclusions: There is a positive correlation between the population density of A. aegypti and the number of human cases and duration of outbreaks. This was not observed for Aedes albopictus. Three pools of A. aegypti were positive with dengue virus, two with DENV-1 and one with DENV-2.