Comparison of diferent diagnostic tests in dogs uninfected and naturally infected with visceral leishmaniasis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphological, immunohistochemical and molecular study of renal lesions in canine visceral leishmaniasis (CVL)

Canine visceral leishmaniasis (CVL) is an anthropozoonosis characterized by a clinically chronic progressive disease. Non lymphoid organs are also affected, especially the kidneys. Dogs with leishmaniasis usually die with renal failure despite treatment. Haematoxylin-eosin (HE) staining in kidney tissue sections has low sensitivity for parasite identification. Immunohistochemistry (IHC) and polymerase chain reaction (PCR) are efficient methods for Leishmania sp. antigen and DNA detection in cases of low parasite burden. The present study aims to identify renal lesions of CVL and correlate them with microscopic findings determined by histochemistry, IHC and PCR. Both IHC and PCR provided similar positivity for amastigote identification, 3/20 animals (15%), thus increasing detection of the parasite in renal tissues when compared with histopathologic examination. The lesion most commonly observed with visceral leishmaniasis-positive canine kidney tissue was membranoproliferative glomerulonephritis, followed by interstitial nephritis without correlation to the number of amastigotes.

Coinfection of Leishmania chagasi with Toxoplasma gondii, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) in cats from an endemic area of zoonotic visceral leishmaniasis

The aim of the present study was to determine the coinfection of Leishmania sp. with Toxoplasma gondii, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) in a population of cats from an endemic area for zoonotic visceral leishmaniasis. An overall 66/302 (21.85%) cats were found positive for Leishmania sp., with infection determined by direct parasitological examination in 30/302(9.93%), by serology in 46/302(15.23%) and by both in 10/302 (3.31%) cats. Real time PCR followed by amplicon sequencing successfully confirmed Leishmania infantum (syn Leishmania chagasi) infection. Out of the Leishmania infected cats, coinfection with FIV was observed in 12/66(18.18%), with T. gondii in 17/66 (25.75%) and with both agents in 5/66(7.58%) cats. FeLV was found only in a single adult cat with no Leishmania infection. A positive association was observed in coinfection of Leishmania and FIV (p < 0.0001), but not with T. gondii (p > 0.05). In conclusion, cats living in endemic areas of visceral leishmaniasis are significantly more likely to be coinfected with Fly, which may present confounding clinical signs and therefore cats in such areas should be always carefully screened for coinfections. (C) 2012 Elsevier B.V. All rights reserved.

Identification of Leishmania infantum chagasi proteins in urine of patients with visceral leishmaniasis: a promising antigen discovery approach of vaccine candidates

Visceral leishmaniasis (VL) is a serious lethal parasitic disease caused by Leishmania donovani in Asia and by Leishmania infantum chagasi in southern Europe and South America. VL is endemic in 47 countries with an annual incidence estimated to be 500 000 cases. This high incidence is due in part to the lack of an efficacious vaccine. Here, we introduce an innovative approach to directly identify parasite vaccine candidate antigens that are abundantly produced in vivo in humans with VL. We combined RP-HPLC and mass spectrometry and categorized three L. infantum chagasi proteins, presumably produced in spleen, liver and bone marrow lesions and excreted in the patients urine. Specifically, these proteins were the following: Li-isd1 (XP_001467866.1), Li-txn1 (XP_001466642.1) and Li-ntf2 (XP_001463738.1). Initial vaccine validation studies were performed with the rLi-ntf2 protein produced in Escherichia coli mixed with the adjuvant BpMPLA-SE. This formulation stimulated potent Th1 response in BALB/c mice. Compared to control animals, mice immunized with Li-ntf2+ BpMPLA-SE had a marked parasite burden reduction in spleens at 40 days post-challenge with virulent L. infantum chagasi. These results strongly support the proposed antigen discovery strategy of vaccine candidates to VL and opens novel possibilities for vaccine development to other serious infectious diseases.

Ecological Aspects of Phlebotomines (Diptera: Psychodidae) in Endemic Area of Visceral Leishmaniasis, Campo Grande, State of Mato Grosso do Sul, Brazil

Aspects of phlebotomine behavior were investigated in the city of Campo Grande, Mato Grosso do Sul state. The insects were captured weekly during December 2003 to November 2005, with Centers for Disease Control light traps at seven different sites including forests and residential areas. In total, 11,024 specimens (7,805 males and 3,219 females) were collected, from which 9,963 (90.38%) were identified as Lutzomyia longipalpis, the proven vector of American visceral leishmaniasis agent. The remaining 9.62% comprised 21 species. L. longipalpis was the most frequent species in all sampled sites, and the first in the ranking of standardized species abundance index. In residential areas this species clearly predominated in the peridomicile (90.96%), in contrast to the intradomicile (9.04%); in animal shelters, it was more numerous in hen houses and prevailed at ground level, inside, and at forest edge around the residences; this aspect is worrying because this insect may remain sheltered in forested environments during the use of insecticides in homes. In the forest environment, other probable or proven vector of cutaneous leishmaniasis agents were also captured such as Lutzomyia whitmani (=Nyssomyia whitmani, sensu Galati), Lutzomyia antunesi (=Nyssomyia antunesi, sensu Galati), and Lutzomyia flaviscutellata (=Bichromomyia flaviscutellata, sensu Galati).

Space-time cluster analysis of American visceral leishmaniasis in Bauru, Sao Paulo State, Brazil

A space-time analysis of American visceral leishmaniasis (AVL) in humans in the city of Bauru, Sao Paulo State, Brazil was carried out based on 239 cases diagnosed between June 2003 and October 2008. Spatial analysis of the disease showed that cases occurred especially in the city's urban areas. AVL annual incidence rates were calculated, demonstrating that the highest rate occurred in 2006 (19.55/100,000 inhabitants). This finding was confirmed by the time series analysis, which also showed a positive tendency over the period analyzed. The present study allows us to conclude that the disease was clustered in the Southwest side of the city in 2006, suggesting that this area may require special attention with regard to control and prevention measures.

Space-time cluster analysis of American visceral leishmaniasis in Bauru, São Paulo State, Brazil

A space-time analysis of American visceral leishmaniasis (AVL) in humans in the city of Bauru, São Paulo State, Brazil was carried out based on 239 cases diagnosed between June 2003 and October 2008. Spatial analysis of the disease showed that cases occurred especially in the city's urban areas. AVL annual incidence rates were calculated, demonstrating that the highest rate occurred in 2006 (19.55/100,000 inhabitants). This finding was confirmed by the time series analysis, which also showed a positive tendency over the period analyzed. The present study allows us to conclude that the disease was clustered in the Southwest side of the city in 2006, suggesting that this area may require special attention with regard to control and prevention measures.

Visceral leishmaniasis in Brazil: trends and challenges

The urbanization of visceral leishmaniasis in Brazil has been related to environmental changes, migration, interaction and spread of sylvatic reservoirs and infected dogs to areas with no transmission, and adaptation of the vector Lutzomyia longipalpis to the peridomiciliary environment. From 1980 to 2005, Brazil recorded 59,129 cases of visceral leishmaniasis, 82.5% of which in the Northeast region. Visceral leishmaniasis gradually spread to other regions of the country: in 1998 these other regions reported 15% of all cases, but by 2005 this proportion had increased to 44%. From 1998 to 2005, indigenous cases were reported in 1,904 different municipalities of the country (34.2%). Reservoir and vector control pose major challenges for disease control, since there is a need for better knowledge of vector behavior in urban areas, and control activities involve high operational costs. In recent years the Brazilian Ministry of Health has supported research on the laboratory diagnosis of infection and disease in humans and dogs, treatment of patients, evaluation of the effectiveness of control strategies, and development of new technologies that could contribute to the surveillance and control of visceral leishmaniasis in the country.

USEFULNESS OF kDNA PCR IN THE DIAGNOSIS OF VISCERAL LEISHMANIASIS REACTIVATION IN CO-INFECTED PATIENTS

It is important to develop new methods for diagnosing relapses in the co-infection of visceral leishmaniasis (VL) and HIV to enable earlier detection using less invasive methods. We report a case of a co-infected patient who had relapses after VL treatment, where the qualitative kDNA PCR showed a good performance. The kDNA PCR seems to be a useful tool for diagnosing VL and may be a good marker for predicting VL relapses after treatment of co-infected patients with clinical symptoms of the disease.

Anti-Leishmania infantum IgG Antibody Avidity in Visceral Leishmaniasis

IgG avidity tests are used to discriminate acute from chronic infections. There are few reports on the IgG avidity profile of patients with visceral leishmaniasis (VL). This study investigated the anti-Leishmania IgG avidity in patients with classic VL (n = 10), patients showing clinical cure after treatment (n = 18), and asymptomatic subjects with at least one positive Leishmania test (n = 20). All subjects were from areas in Brazil where VL is endemic. Serum samples were collected from each subject on two different occasions. IgG avidity was evaluated by Western blotting. The proportion of high-avidity antibodies was higher in all samples from patients with classic VL. In contrast, low-avidity antibodies predominated in subjects with a history of VL, including 13 cases (72.2%) in the first assessment and 14 (77.8%) in the second. Fifteen (75%) of the asymptomatic subjects presented a predominance of low-avidity antibodies in the first assessment, and the frequency of high-avidity antibodies increased over time in seven subjects (35%) of this group. Antibodies against the 14- and/or 16-kDa antigen fraction were detected in the first assessment in all patients with classic VL, in 10 (55.5%) treated patients, and in 10 (50%) asymptomatic subjects. These were high-avidity antibodies in most cases. In the asymptomatic group, an increase in IgG avidity against the 14- and/or 16-kDa antigen fraction was observed in three cases (15%). The results indicate distinct responses in infected and asymptomatic subjects, probably associated with the length of time after infection. In this respect, IgG avidity tests represent a new approach to better characterize asymptomatic VL.

Holiday souvenirs from the Mediterranean: three instructive cases of visceral leishmaniasis

With expanding travel activities, visceral leishmaniasis increasingly occurs in non-endemic areas and affects immunocompetent individuals with no other risk factor than holidays at the Mediterranean coast. We report 3 instructive Swiss cases of visceral leishmaniasis presenting with fever of unknown origin and pancytopenia and review current diagnostic and therapeutic concepts.

Randomised controlled trial of aminosidine (paromomycin) v sodium stibogluconate for treating visceral leishmaniasis in North Bihar, India

Objectives: To assess the efficacy and tolerability of aminosidine compared with sodium stibogluconate for treating visceral leishmaniasis.

Arsenic exposure and outcomes of antimonial treatment in visceral leishmaniasis patients in Bihar, India : a retrospective cohort study

Funding: This work was supported by a Clinical PhD Fellowship to MRP (090665) and a Principal Research Fellowship to AHF (079838) from the Wellcome Trust (http://www.wellcome.ac.uk). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Density of sand flies (diptera: psychodidae) in domestic and wild animal shelters in an area of visceral leishmaniasis in the state of Rio Grande do Norte, Brazil

XIMENES, Maria de Fátima Freire de Melo; SOUZA, Maria de Fátima de; CASTELLON, Eloy Guilhermo. Density of sand flies (Diptera: Psychodidae) in domestic and wild animal shelters in an area of visceral Leishmaniasis in the State of Rio Grande do Norte, Brazil. Memorias do Instituto Oswaldo Cruz, Rio de Janeiro, v.94, n.4, p.427-432, jul./ago. 1999. Disponivel em: Acesso em: 4 out. 2010.