Deltamethrin-impregnated dog collars have a potent anti-feeding and insecticidal effect on Lutzomyia longipalpis and Lutzomyia migonei

Deltamethrin-impregnated PVC dog collars were tested to assess if they were effective in protecting dogs from sand fly bites of Lutzomyia longipalpis and Lu. migonei. A protective effect against Old World species Phlebotomus perniciosus was demonstrated before. Four dogs wearing deltamethrin collars and three dogs wearing untreated collars (not impregnated with deltamethrin) were kept in separate kennels for over eight months in a village on the outskirts of Fortaleza in Cearß, Brazil. Periodically, a dog from each group was sedated, placed in a net cage for 2 h in which 150 female sand flies had been released 10-15 min before. Lu. longipalpis were used 4, 8, 12, 16, 22, 27, and 35 weeks after the attachment of the collars. Lu. migonei were used 3, 7, 11, 15, 22, 26, and 36 weeks after attachment. During 35 weeks, only 4.1 percent (81 of 2,022) Lu. longipalpis recovered from the nets with the deltamethrin collared dogs were engorged, an anti-feeding effect of 96 percent. Mortality initially was over 90 percent and at 35 weeks was 35 percent with half of the sand flies dying in the first 2 h. In contrast, 83 percent of the 2,094 Lu. longipalpis recovered from the nets containing the untreated collared dogs were engorged and the mortality ranged from zero to 18.8 percent on one occasion with 1.1 percent dying in the first 2 h. Similar findings were found with Lu. migonei: of 2,034 sand flies recovered over this period, only 70 were engorged, an anti-feeding effect of 96.5 percent, and mortality ranged from 91 percent initially to 46 percent at 36 weeks. In contrast, engorgement of controls ranged from 91 to71 percent and a mortality ranged from 3.5 to 29.8 percent. These studies show that deltamethrin impregnated collars can protect dogs against Brazilian sand flies for up to eight months. Thus, they should be useful in a program to control human and canine visceral leishmaniasis

Effect of Lutzomyia whitmani (Diptera: Psychodidae) salivary gland lysates on Leishmania (Viannia) braziliensis infection in BALB/c mice

Previous reports showed that Lutzomyia longipalpis saliva exacerbate Leishmania braziliensis infection in mice. The sand fly Lu. whitmani is one of the vectors of L. (Viannia) braziliensis (LVb), a causative agent of cutaneous leishmaniasis in the State of Ceará, Brazil. To determine whether saliva of Lu. whitmani could increase the infectivity of LVb in mice, we inoculated groups of BALB/c mice with LVb promastigotes in the presence or absence of the salivary glands lysate from Lu. whitmani. We found that coinjection with Lu. whitmani saliva increased size but not longevity of cutaneous LVb lesions in BALB/c mice, since the formed lesions gradually resolved. The mechanism(s) by which Lu. whitmani saliva might exacerbate LVb infection in BALB/c mice is speculated

Avaliaçäo do teste de aglutinaçäo direta na detecçäo da infecçäo por Leishmania (Viannia) braziliensis em possíveis reservatórios de leishmaniose tegumentar americana no estado do Ceará / Evaluation of the direct agglutination test for detecting of the Leishmania (Viannia) braziliensis infection reservoir hosts of american cutaneous leishmaniasis in the State of Ceará

In order to evaluate the aplicability of the Direct Agglutination Test (DAT) as a method of detection of the natural canine infection for Leishmania (Viannia) braziliensis, it was realized a study involving the serum of naive dogs from Serra de Baturite, Ceara State, an endemic area of cutaneous leishmaniasis, and others from Curitiba, Parana State, a non endemic area. The results indicate the possibility of using this sorologic test to the epidemiologic research of the infection in the reservoir host; in this case, the dog.