No abstract

An entomological survey of Aedes mosquitoes was initiated at the container terminal of the Autonomous Port of Abidjan in 2009 following the occurrence of two outbreaks of yellow fever in less than 10 years and dengue cases reported in 2008 among expatriates returning from Côte d’Ivoire (Ivory Coast). It was based on regular monitoring of ovitraps from July 2009 to June 2010. A total of 4,739 adult mosquitoes represented by four species of Aedes (97% of total) and one unexpected species of Culex (3%) were obtained. Aedes aegypti was dominant with 98% of total Aedes (n = 4,594). Its density variation was closely related to the amount of rainfall. The other species of Aedes were collected in the second half of the major rainy season including Ae. albopictus (1.17% of Aedes) and Ae. angustus (0.13%) whose presence was discovered for the first time in Côte d’Ivoire.

In April 2008, Abidjan was again faced with another case of yellow fever after the epidemic of 2001 causing mass immunization campaign. In order to evaluate the extent of amaril virus circulation and the risk for local people, an entomological investigation was carried out by the Ministry of Health and Public Hygiene of Côte d'Ivoire. At "Entent" area of Treichville, Breteau index was estimated at 34, recipient index at 20 % and house index at 25 %. Those indexes were respectively 53, 21 and 31 % at "Vridi canal" of Port Bouet. In the both neighborhood, Aedes aegypti accounted for more than 80 % of mosquitoes caught and more than 90 % of mosquitoes adults obtained from larval breeding. This new situation of epidemic risk could be explained by several factors including the reception of 70 % of forced migration people caused by the crisis in the country occurred in 2002, the probable drop of preventive immunization, the environment deterioration creating of more breeding sites of Ae. aegypti. Résumé

Dengue has become a major public health concern in Cote d'Ivoire since 2010. In malaria endemic countries, such as Cote d'Ivoire, healthcare workers often confuse dengue with other tropical fevers, such as malaria. However, to control dengue fever, healthcare workers must be knowledgeable about this disease. A cross-sectional study was conducted on 400 healthcare workers' knowledge, attitude, and practices in relation to dengue from 3 rd September, 2014 to 20 th March, 2015 in Abidjan and its suburbs. Logistic analyses with stepwise selection were performed to explain the relationship between the dependent variable (practices) and the main explicative variable (knowledge). The distribution of participant healthcare workers by health facility showed that 55% worked in reference health facilities. Among the 340 participants, 70 (21%) had a good knowledge of dengue fever, while 71 (21%) had good diagnostic practices. The logistical analysis with stepwise selection showed that practices were explained by knowledge (adjusted OR (aOR) = 2.69; p = 0.004), gender (aOR = 1.88; p = 0.036), occupation (aOR = 0.37; p = 0.003) and epidemic risk perception (aOR = 2.59; p = 0.001). The study shows that nurses had better practices in term of dengue diagnosis compared with medical doctors. Similarly, healthcare workers who had good knowledge of dengue fever also had good practices. However, there is a great need for healthcare workers to be trained on how to detect dengue disease.

Since 2008, several outbreaks of yellow fever and dengue occurred in Abidjan, the economic capital of Côte d'Ivoire. A better knowledge of the biology of Aedes aegypti populations, the main vector of yellow fever and dengue viruses, is necessary to tailor vector control strategies implemented in the city. This study was designed to determine some biological parameters, occurring during the life cycle of two morphological phenotypes of Ae. aegypti larvae. Mosquitoes were sampled in a suburb of Abidjan (Treichville) using the WHO layer-traps technique. Biological parameters were studied in laboratory under standard conditions of temperature (27°C ± 2°C) and relative humidity (80% ± 10%). Our results indicated that the mean eggs laid by females from 'brown larvae' (BL) (85.95, 95% confidence interval (CI 95%) 78.87-93.02) was higher than those from 'white larvae' (WL) (64.40%, CI 95% 55.27-73.54). The gonotrophic cycle was 3 and 4 days in females from BL and WL, respectively. The overall yield of breeding mosquitoes from BL (63.88%, CI 95% 62.61-65.14) was higher compared with those of mosquitoes from WL (59.73%, CI 95% 58.35-61.12). The sex ratio (male/female) was 0.95 and 1.68 in Ae. aegypti populations from BL and WL, respectively. Females from BL lived slightly longer than those from WL (t = -2.332; P = 0.021). This study shows that Ae. Aegypti populations from BL and WL present different biological parameters during their life cycle. This could have an implication on their ability to transmit human disease viruses such as dengue and yellow fever. Further molecular studies are needed to determine genetic divergence between these Ae. aegypti populations.