Mosquito species geographical distribution in Iraq 2009

Mosquitoes transmit diseases to >700 million people annually. Malaria kills three million persons every year, including one child every 30 sec. Worldwide there are >3000 mosquito species. In Iraq, 37 species have been identified in different surveys over several decades. We conducted an entomological survey to determine the mosquito species and their distribution in Iraq in 2009.

Between January 20 and December 31, 2009, mosquitoes in houses in 12 Iraqi provinces were collected and speciated. Five to 10 villages were selected randomly in each province and in each village 10 houses were selected randomly to collect mosquitoes and the density of mosquitoes per room was calculated. Kits for entomological investigation were used and the collected mosquitoes were sent to the vector borne disease section laboratory for classification using the Naval Medical Research Unit 3 standard classification key.

A total of 29,156 mosquitoes were collected, representing two genera: Anopheles (n=13,268, or 46% of the total collected) and Culex (n=15,888, or 54% of the total collected). Four Anopheles (An. pulcherrimus, An. stephensi, An. superpictus, and An. sacharovi) and one Culex (Cx. pipiens) species were identified. Anopheles pulcherrimus was found in 11 provinces, An. stephensi in 7, An. superpictus in 2 and An. sacharovi in one province, while Cx. pipiens was found in all the 12 provinces. Two peaks of mosquito density were found: the first from April-June and the other from September-October.

There are clear differences in Anopheles mosquito species geographical distribution and density among Iraqi provinces, while Cx. pipiens mosquitoes are distributed all over Iraq. All mosquito genera show clear seasonal density variation. The study highlights that the manual mosquito classification is not enough to identify all the species of mosquitoes in Iraq.