ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
A prospective case–control study was conducted in urban districts in Hanoi, northern Vietnam to evaluate the effect of migration on the risk of hospitalisation for dengue in a Vietnamese urban population. We enrolled laboratory-confirmed dengue patients aged >18 years who were hospitalised in local hospitals in November and December 2010. Four neighbourhood-matched controls for each case were recruited within a week of hospitalisation. Sociodemographic data were collected by interviews, and the number of immature and adult mosquitoes within household premises was counted by entomological survey. Matched-pair analyses were conducted using conditional logistic regression models. Among 43 cases and 168 controls, 84% and 83% were migrants from rural areas, respectively. Although statistical significance was marginal, recent migration (residing in study area for 6 years) did not change the risk (aOR = 1.1; 95% CI = 0.30–4.05). Younger age (18–34 years) (aOR = 7.26; 95% CI = 2.39–22.06) and higher adult Aedes aegypti infestation level within household premises (aOR = 9.25; 95% CI = 1.68–51.09) were also independently associated with hospitalisation for dengue. Recent migration from rural areas seems to increase the risk of hospitalisation for dengue in urban populations in endemic areas. Further research including cohort study should be done to confirm the impact of migration on the risk of dengue in urban areas.