ABSTRACT
Zoonotic cutaneous leishmaniasis (ZCL) due to Leishmania major (Yakimoff and Schokhor, 1914) is known as a neglected tropical disease, transmitted by Phlebotomus papatasi (Scopoli, 1786) in North Africa and the Middle East. The main reservoirs of ZCL are desert gerbils and the role of humans as a reservoir host of the disease is not clearly defined and is therefore investigated in this study. In order to achieve this objective, Ph. papatasi sand flies were allowed to take blood through indirect blood sources (human, Rhombomys opimus (Lichtenstein, 1823) (great gerbil), and BALB/c mice) using artificial feeding or direct xenodiagnoses from ZCL patients. To detect Leishmania promastigotes inside digestive canal, blood-fed sand flies were dissected and examined under light microscope and then confirmed by nested-PCR. In indirect xenodiagnoses, promastigote forms of Leishmania parasite were observed in 7.1%, 12%, and 13.6% of sand flies which fed on Rh. opimus, BALB/c mice, or human blood sources, respectively. In direct xenodiagnoses, among 93 female lab-reared sand flies which fed on active L. major lesion(s), 2.1% Leishmania infection was subsequently observed in the sand flies. No infection was detected in those sand flies that fed on nonlesioned skin of CL patients. Humans can serve as a reservoir of ZCL since the data indicate that Ph. papatasi is able to acquire L. major parasites from an active lesion of ZCL patients and the parasites can complete metacyclogenesis in the sand fly.
Subject(s)
Disease Reservoirs/parasitology , Leishmania major , Leishmaniasis, Cutaneous/transmission , Zoonoses/parasitology , Animals , Female , Humans , Insect Vectors/parasitology , Male , Mice , Mice, Inbred BALB C , Phlebotomus/parasitology , XenodiagnosisABSTRACT
BACKGROUND: Establishment of sand flies laboratory colonies is essential to understand various biological aspects of Phlebotominae sand flies. The aims of the current study were to establish the colony of Phlebotomus sergenti Parrot (1917), the main vector of anthroponotic cutaneous leishmaniasis in old world, and to study biological parameters of this species. METHODS: The sand flies were reared at 26-28 °C temperature, 14:10 (light: dark) photoperiod and 70-80% relative humidity. Larval diet was a composted mixture of rabbit faces and rabbit pellets which is prepared through a special process. First to fifth generations of P. sergenti were used to define biological parameters. RESULTS: Results showed that, P. sergenti blood feeding percentage were 42% on chicken, 21% on BALB/c and 37% on golden hamster. Average time of blood digestion, egg incubation, 1st instar larva, pupa and adult emerging was recorded at 3.4, 8.7, 15, 33.3 and 41.2 days after blood feeding, respectively. Mean number of laid eggs was 55.1 and retained eggs were 35 per a female. Fecundity and production rate were 61.6%, and 42.2% respectively. Average longevity recorded at 15.2 days for females and 14.8 days for males. CONCLUSION: Colony of P. sergenti has been established for the first time in Iran. Average interval time from egg to adult of this species was 32.5 days. Chicken and golden hamster were recommended as a blood source for colony initiation and routine blood feeding, respectively.
ABSTRACT
BACKGROUND: Phelebotumus papatsi is considered to be the main vector of zoonotic cutaneous leishmaniasis as well as sand fly fever in Iran. There are several measures for vector control, with emphasis on insecticides. The objective of this study was to determine the baseline susceptibility of this vector to the commonly used insecticides in an endemic focus of the disease in central Iran. P. papatasi collected from the field were used for susceptibility status. Its baseline susceptibility to DDT and pyrethroids was assessed on about 6866 specimens collected from Badrood rural district, Esfahan Province, Iran, during the summer of 2010. The LT(50) and LT(90) values were measured according to the World Health Organisation (WHO) test using probit analysis and regression lines. RESULTS: Results of tests against female P. papatasi revealed LT(50) values to DDT 4%, permethrin 0.75%, deltamethrin 0.1%, cyfluthrin 0.15% and lambdacyhalothrin 0.05% of 1104.97, 182.35, 26.79, 15.42 and 1.48 s respectively. The figures for male P. papatasi were 973.51, 59.5, 4.4, 2.65 and 1.5. CONCLUSION: The results of this study provide a guideline for implementation of different vector control measures. Furthermore, guidelines are needed for monitoring and evaluation of insecticide susceptibility tests against sand flies.
