Haematophageous vector monitoring in Djibouti city from 2008 to 2009: first records of culex pipiens ssp. torridus [iglisch], and anopheles sergentii [theobald]

The Horn of Africa represents a region formerly known to be highly susceptible to mosquito-borne infectious diseases. In order to monitor and analyze the current presence and threat of vector mosquitoes, continuous and standardized trapping using CDC light traps without an additional CO2-generator has been carried out at six selected monitoring sites located in Djibouti City, from August 2008 until December 2009. An overall of 620 haematophageous Diptera were trapped, 603 [97.3%] were mosquitoes, 10 [1.6%] were sand flies, and 7 [1.1%] were biting midges, respectively. Genus distribution of mosquitoes revealed that 600 [99.5%] were Culex spp., 2 [0.3%] were Anopheles sergentii, and 1 [0.2%] was Aedes aegypti. Culex species were represented by Cx. quinquefasciatus [78.5%], and Cx. pipiens ssp. torridus [21.5%]. The later species was first detected focally in early December 2009 showing a strongly increasing population density resulting in a maximum trap rate of 25 mosquitoes per trap night. Sand flies were all Sergentomyia antennata, and biting midges of the genus Culicoides were represented by C. nubeculosus [71.4%] and C. vexans [28.6%]. The findings included the first records for Cx. pipiens ssp. torridus and An. sergentii in Djibouti. However, none of the captured female Culex spp, the known vector for West Nile Virus, showed positive results for viral nucleic acids using WNV RT-real time PCR system. Also, females An. sergentii were Plasmodium falciparum and P. vivax circumsporozoite protein negative

Epidemiology of plasmodium falciparum and P. vivax malaria endemic in Northern Afghanistan

In 2002, the total malaria burden in Afghanistan was estimated to be 3 million cases annually, mainly from Takhar and Kunduz Provinces. Field investigations from 2001 to 2007 revealed a rapid resurgence of Plasmodium falciparum and P. vivax malaria, with annual incidence rates between 0.0026 and 4.39, and between 0.88 and 13.37 episodes/1,000 person years, respectively. Both diseases peaked during 2002, and then declined independently, indicating two differing modes of transmission and epidemiology. Although control campaigns against malaria tropica, transmitted by the freshwater breeder Anopheles superpictus, were successful, malaria teitiana remained endemic and associated with rice-growing areas, transmitted by the anthropophilic, endophilic or exophilic rice-field breeder, A. pulcherrimus and A. hyrcanus. P. vivax polymorph VK 247 prevailed in 90% of infected mosquito pools. Data documented anthropogenically induced increases in rice-field malaria tertiana in the rice-growing areas of northern Afghanistan and the need for further control strategies, including large-scale larval mosquito eradication in rice-growing areas