Preliminary Screening of Mosquito Spatial Distribution in Togo: With Special Focus on the Aedes (Diptera: Culicidae) Species.

The Togolese Republic has a tropical and humid climate which constitutes an ideal environment for mosquitoes to breed and transmit diseases. The Aedes mosquito is known to transmit yellow fever (YF), dengue, chikungunya, and Zika viruses in West Africa. Togo has been suffering from YF virus transmission, despite vaccination efforts. Unfortunately, there is scarcity in the data that reflect mosquito spatial distribution in Togo, specifically possible YF vectors. In the current study, mosquito surveillance efforts targeted areas with confirmed YF cases between July and August 2012. Indoor mosquitoes were collected using knockdown insecticide spraying, whereas Biogents (BG) traps were used to collect outdoor mosquito adults. Mosquito larval surveillance was conducted as well. In total, 17 species were identified. This investigation revealed the presence of medically important vectors in Togo, especially the Aedes aegypti (Linnaeus) (Diptera: Culicidae) which was collected in the four regions. Screening of all pools of female Aedes mosquitoes for YF, by real-time PCR, showed negative results. This is the first record for Coquillettidia flavocincta (Edwards) (Diptera: Culicidae) species in West Africa. This preliminary work serves as a baseline for further mosquito distribution studies in Togo.

Experimental effect of feeding on Ricinus communis and Bougainvillea glabra on the development of the sand fly Phlebotomus papatasi (Diptera: Psychodidae) from Egypt.

Plants are promising sources of agents useful for the control of vectors of human diseases including leishmaniasis. The effect of Ricinus communis (Euphorbiaceae) and Bougainvillea glabra (Nyctaginaceae), on transmission of leishmaniasis was investigated using them as diets for Phlebotomus papatasi to monitor their effect on life-history traits. P. papatasi were allowed to feed separately on both plants then offered a blood-meal. Fed-females were observed daily for egg-laying and subsequent developmental stages. P. papatasi was able to feed on B. glabra (29.41% females and 46.30% males) and R. communis (5.80% females and 10.43% males). 34.28% of females died within 24-48 hours post-feeding on R. communis, whereas, it was 16.5% in females fed on B. glabra. Overall fecundity of surviving females was reduced compared to controls, reared on standard laboratory diet; however there was no effect on the sex ratio of progeny. Female P. papatasi in the control group had significantly longer life span compared to plant-fed group. Feeding on these plants not only decreased sand fly survival rates but incurred negative effects on fecundity. Findings indicate that planting high densities of R. communis and B. glabra in sand flies-endemic areas will reduce population sizes and reduce the risk of Leishmania major infections.

Experimental acquisition, development, and transmission of Leishmania tropica by Phlebotomus duboscqi.

We report experimental infection and transmission of Leishmania tropica (Wright), by the blood-feeding sand fly Phlebotomus duboscqi (Neveu-Lemaire). Groups of laboratory-reared female sand flies that fed "naturally" on L. tropica-infected hamsters, or artificially, via membrane feeding device, on a suspension of L. tropica amastigotes, were dissected at progressive time points post-feeding. Acquisition, retention and development of L. tropica through procyclic, nectomonad, and leptomonad stages to the infective metacyclic promastigote stage, and anterior progression of the parasites from abdominal midgut bloodmeal to the thoracic midgut were demonstrated in both groups. Membrane feeding on the concentrated amastigote suspension led to metacyclic promastigote infections in 60% of sand flies, whereas only 3% of P. duboscqi that fed naturally on an infected hamster developed metacyclics. Sand flies from both groups re-fed on naïve hamsters, but despite infections in 25-50% of membrane-fed and 2-3.5% of naturally fed flies, no skin lesions developed in the hamsters. After four months of observation these animals were euthanized and necropsied. Screening of the organs and tissue by polymerase chain reaction (PCR) that targeted the small subunit RNA gene, amplified generic Leishmania DNA from liver, spleen, bone marrow, and blood, but only from hamsters bitten by membrane-infected P. duboscqi. These results are notable in demonstrating the ability of P. duboscqi, originating from Kenya, to acquire, retain, develop, and transmit a Turkish strain of L. tropica originally isolated from a human case of cutaneous leishmaniasis. This marks the first demonstration of complete development and transmission of L. tropica by a member of the Phlebotomus subgenus of sand flies.

First report of Leishmania tropica from a classical focus of L. major in North-Sinai, Egypt.

Cutaneous leishmaniasis (CL) is prevalent in the Egyptian Sinai Peninsula and previous research has consistently documented the etiologic agent to be Leishmania major. We report the first isolation of Leishmania tropica from human cases of CL in a Northern Sinai community bordering Palestine. Parasite culturing, real-time polymerase chain reaction (PCR), gene sequencing, and restriction fragment length polymorphism (RFLP) analyses indicate CL cases in this community were caused by either L. major or L. tropica (three cases each). Two wild-caught rodents (Gerbillus pyramidum floweri) were infected with L. tropica. Phlebotomus papatasi sand flies were found harboring L. major, however only non-infected individuals of Phlebotomus sergenti, a vector for L. tropica, were caught. Patients with L. tropica had not traveled from the region in over a year, suggesting these cases are autochthonous. This scenario is consistent with an incursion of L. tropica from bordering countries and raises concerns about expansion of this parasite further into Egypt.