A study on Leishmania infection rate among Phlebotomus spp. collected from Abardejh district, Iran

Cutaneous leishmaniasis is a prevalent tropical parasitic disease in the Old World. The causative agents are Leishmanial parasites, which cause various forms of cutaneous leishmaniasis. The infection is commonly limited in immuno-competent individuals, but it can progress to a chronic and ulcerative disease in immuno-compromised patients. The reservoirs are dogs and rodents and the vectors are different species of sandflies. In the present study, we investigated the prevalence rate of Leishmania infection among Phlebotomus mosquitoes collected from Abardejh district, Iran. Abardejh is located next to Varamin city in southeast of Tehran having a tropical ecosystem at its eastern border. Tamarisk trees and rodents have provided a suitable condition for sandfly activity. The sandflies were collected by funnel trap from rodent burrows and transferred to the Department of Parasitology, Pasteur Institute of Iran. The sampling was carried out during spring and summer (2002) with ten-day intervals. The collected sandflies were identified using discriminative morphologic features before parasitological culture on NNN medium. Analyses of the data revealed a high prevalence rate of infection among the sandflies in this region (P<0.01). The maximum activities of Phlebotomus were in the months of June and July. Three species of sanflies were found in rodent burrow: P. papatasi, P. sergenti, and P. caucasicus. The results of blood-fed Phlebotomus culture showed that 22.07% of blood-fed females of P. papatasi and 8% of blood-fed females of P. sergenti were infected with leptomonads (P<0.05). This could be an important issue because human and agricultural environments are located closely to this district. Therefore, use of insecticides and environmental sanitation seems to be required to prevent the transmission of infection from sandflies to human.