Canine leishmaniasis transmission: higher infectivity amongst naturally infected dogs to sand flies is associated with lower proportions of T helper cells

Guarga, Jose Luis; Moreno, Javier; Lucientes, Javier; Lamelas, María Teresa; Peribáñez, Miguel A.; Alvar, Jorge; Castillo, Juan Antonio

doi:10.1053/rvsc.2000.0419

Cited by 79 publications

(53 citation statements)

References 30 publications

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“…These observations are in accordance with previous ones from other authors (22,28,39,42), demonstrating the epidemiological importance of the diversity of clinical status in the transmission of the parasite.…”

Section: Vol 52 2008 Reduced Tissue Parasitic Load and Infectivity supporting

confidence: 93%

Reduced Tissue Parasitic Load and Infectivity to Sand Flies in Dogs Naturally Infected by Leishmania ( Leishmania ) chagasi following Treatment with a Liposome Formulation of Meglumine Antimoniate

Ribeiro¹,

Moura²,

Pimentel³

et al. 2008

Antimicrob Agents Chemother

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The toxicity and antileishmanial effectiveness of a novel liposome formulation of meglumine antimoniate in mongrel dogs with visceral leishmaniasis (VL) obtained from a region where VL is endemic in Brazil have been investigated. Groups of 12 animals received by the intravenous route four doses (with 4-day intervals) of either liposomal meglumine antimoniate (group I [GI], 6.5 mg Sb/kg of body weight/dose), empty liposomes (GII), or isotonic saline (GIII). Evaluation of markers of hematopoietic, hepatic, and renal functions before and just after treatment showed no significant change. On the other hand, transitory adverse reactions, including prostration, defecation, tachypnea, and sialorrhea, were observed during the first 15 min after injections in GI and GII. Parasitological evaluation of sternal bone marrow 4 days after the last dose showed a significant reduction of parasite burden in GI, compared to the other groups. Immunocytochemical evaluations of the skin, bone marrow, cervical lymph nodes, livers, and spleens of dogs for parasites, 150 days after treatment, indicated significant parasite suppression (higher than 95.7%) in the lymph nodes, livers, and spleens of GI, compared to control groups. Feeding of Lutzomyia longipalpis phlebotomines on dogs from GI, 150 days after treatment, resulted in a significant reduction of sand fly infection efficiency, compared to feeding on animals from GII and GIII. This is the first report of both long-term parasite suppression and reduction of infectivity to sand flies in naturally infected dogs following treatment with a liposome-encapsulated drug. Importantly, this was achieved using a 20-fold-lower cumulative dose of Sb than is used for conventional antimonial treatment.

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Section: Vol 52 2008 Reduced Tissue Parasitic Load and Infectivity supporting

confidence: 93%

Reduced Tissue Parasitic Load and Infectivity to Sand Flies in Dogs Naturally Infected by Leishmania ( Leishmania ) chagasi following Treatment with a Liposome Formulation of Meglumine Antimoniate

Ribeiro¹,

Moura²,

Pimentel³

et al. 2008

Antimicrob Agents Chemother

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“…18,48,49 In contrast to these observations in Latin America, both asymptomatic and polysymptomatic dogs from the Mediterranean basin were shown to be highly infective to sand flies. 50 This could be caused by the marked vector competence of the Old World species Phlebotomus perniciosus as opposed to the New World species L. longipalpis . 18 Therefore, it could be speculated that immunoprophylactic approaches that prevent animals from reaching the polysymptomatic stage could have greater impact (40) in controlling transmission in the Americas than in the Old World.…”

Section: Discussionmentioning

confidence: 99%

Clinical, Parasitologic, and Immunologic Evolution in Dogs Experimentally Infected with Sand Fly-Derived Leishmania chagasi Promastigotes

Travi¹,

Osorio²,

Saldarriaga³

et al. 2009

The American Journal of Tropical Medicine and Hygiene

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Abstract. Experimental infection of dogs with Leishmania infantum has yielded heterogeneous clinical, parasitologic, and immunologic results. We studied dogs infected with 10 5 or 10 4 sand fly-derived promastigotes delivered by the intradermal (ID) or intravenous (IV) routes. Total mortality over 1 year post-infection reached 23.8%. The mortality and proportion of sustained polysymptomatic dogs was highest in the IV-10 5 group. The early appearance of polysymptoms was associated with an increased risk of progression to death. Dissemination of the parasite to lymph nodes was faster, and the subsequent infectivity to sand flies higher, in the IV compared with ID-infected dogs. Parasite-specific IgG1 or IgG2 production was similar among the groups, but higher interferon-γ (IFN-γ) and interleukin-10 (IL-10) expression was associated with polysymptomatic dogs. On the basis of the data obtained from this study, a sample size analysis using different endpoints for future vaccine trials is described.

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“…In asymptomatic dogs, macrophages are capable of killing amastigotes via the nitric oxide route (Vouldoukis et al, 1996), and there is an increase in CD8+ T-cells in peripheral lymphocytes, and MHC class II molecules and the receptors CD45RA and CD45RB are also expressed (Reis et al, 2006a). In contrast, symptomatic dogs show a failed cellular response, with no IDR or lymphocyte proliferation and the following additional characteristics: decrease in CD14+ monocytes; decrease in CD8+ (Reis et al, 2006a), CD4+ T-lymphocytes, and CD21+ B lymphocytes, either Leishmania -specific or not; antibody increase; deficiency of the co-stimulatory response; decrease of IFN-γ; and reduced expression of MHC class II molecules, which renders the animal more susceptible (Bourdoiseau et al, 1997; Moreno et al, 1999; Pinelli et al, 1999; Guarga et al, 2000, 2002; Borja-Cabrera et al, 2004). …”

Section: Cellular Immune Responses In Canine Zvlmentioning

confidence: 99%

Vaccines for Canine Leishmaniasis

Palatnik-de-Sousa¹

2012

Front. Immun.

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Leishmaniasis is the third most important vector-borne disease worldwide. Visceral leishmaniasis (VL) is a severe and frequently lethal protozoan disease of increasing incidence and severity due to infected human and dog migration, new geographical distribution of the insect due to global warming, coinfection with immunosuppressive diseases, and poverty. The disease is an anthroponosis in India and Central Africa and a canid zoonosis (ZVL) in the Americas, the Middle East, Central Asia, China, and the Mediterranean. The ZVL epidemic has been controlled by one or more measures including the culling of infected dogs, treatment of human cases, and insecticidal treatment of homes and dogs. However, the use of vaccines is considered the most cost–effective control tool for human and canine disease. Since the severity of the disease is related to the generation of T-cell immunosuppression, effective vaccines should be capable of sustaining or enhancing the T-cell immunity. In this review we summarize the clinical and parasitological characteristics of ZVL with special focus on the cellular and humoral canine immune response and review state-of-the-art vaccine development against human and canine VL. Experimental vaccination against leishmaniasis has evolved from the practice of leishmanization with living parasites to vaccination with crude lysates, native parasite extracts to recombinant and DNA vaccination. Although more than 30 defined vaccines have been studied in laboratory models no human formulation has been licensed so far; however three second-generation canine vaccines have already been registered. As expected for a zoonotic disease, the recent preventive vaccination of dogs in Brazil has led to a reduction in the incidence of canine and human disease. The recent identification of several Leishmania proteins with T-cell epitopes anticipates development of a multiprotein vaccine that will be capable of protecting both humans and dogs against VL.

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Canine leishmaniasis transmission: higher infectivity amongst naturally infected dogs to sand flies is associated with lower proportions of T helper cells

Cited by 79 publications

References 30 publications

Reduced Tissue Parasitic Load and Infectivity to Sand Flies in Dogs Naturally Infected by Leishmania ( Leishmania ) chagasi following Treatment with a Liposome Formulation of Meglumine Antimoniate

Reduced Tissue Parasitic Load and Infectivity to Sand Flies in Dogs Naturally Infected by Leishmania ( Leishmania ) chagasi following Treatment with a Liposome Formulation of Meglumine Antimoniate

Clinical, Parasitologic, and Immunologic Evolution in Dogs Experimentally Infected with Sand Fly-Derived Leishmania chagasi Promastigotes

Vaccines for Canine Leishmaniasis

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