Carina Margonari

Epidemiology of visceral leishmaniasis through spatial analysis, in Belo Horizonte municipality, state of Minas Gerais, Brazil

The geographic information system approach has permitted integration between demographic, socio-economic and environmental data, providing correlation between information from several data banks. In the current work, occurrence of human and canine visceral leishmaniases and insect vectors (Lutzomyia longipalpis) as well as biogeographic information related to 9 areas that comprise the city of Belo Horizonte, Brazil, between April 2001 and March 2002 were correlated and georeferenced. By using this technique it was possible to define concentration loci of canine leishmaniasis in the following regions: East; Northeast; Northwest; West; and Venda Nova. However, as for human leishmaniasis, it was not possible to perform the same analysis. Data analysis has also shown that 84.2% of the human leishmaniasis cases were related with canine leishmaniasis cases. Concerning biogeographic (altitude, area of vegetation influence, hydrographic, and areas of poverty) analysis, only altitude showed to influence emergence of leishmaniasis cases. A number of 4673 canine leishmaniasis cases and 64 human leishmaniasis cases were georeferenced, of which 67.5 and 71.9%, respectively, were living between 780 and 880 m above the sea level. At these same altitudes, a large number of phlebotomine sand flies were collected. Therefore, we suggest control measures for leishmaniasis in the city of Belo Horizonte, giving priority to canine leishmaniasis foci and regions at altitudes between 780 and 880 m.

Phlebotomine sand flies (Diptera: Psychodidae) and Leishmania infection in Gafanhoto Park, Divinópolis, Brazil.

ABSTRACT The potential of Gafanhoto Park as an American cutaneous leishmaniasis (ACL) focus was evaluated by examination of sand fly vectors of the Leishmania parasite. This forest remnant is located in a periurban area of Divinópolis, Brazil, where autochthonous cases of ACL have been reported. Sand fly populations were monitored over a 2-yr period (2006–2008) by using light traps (HP and Shannon). During systematic collections with HP traps, 824 specimens in total (342 males and 482 females) of 21 species were captured. Most prevalent species were as follows: Brumptomyia brumpti (Larrouse), Lutzomyia aragaoi (Costa Lima), Lutzomyia lutziana (Costa Lima), Lutzomyia sordellii (Shannon & Del Ponte), and Lutzomyia whitmani (Antunes & Coutinho). Using Shannon traps, 257 specimens representing 15 species were collected (159 females and 98 males), with a high prevalence of L. whitmani and Lutzomyia neivai (Pinto), both vectors of Leishmania braziliensis (Vianna). To ascertain the level of natural infection, a sample of females captured in Shannon traps was assayed for the presence of Leishmania by using polymerase chain reaction-restriction fragment length polymorphism, where 39% of insects were positive. The most infected species was L. whitmani (29 sand flies; 18.2%), followed by L. neivai (21; 13.2%), Lutzomyia christenseni (Young & Duncan) (five; 3.1%), Lutzomyia pessoai (Coutinho & Barreto) (three; 1.9%), L. aragaoi (one; 0.6%), Lutzomyia fischeri (Pinto) (one; 0.6%), Lutzomyia lenti (Mangabeira) (one; 0.6%), L. lutziana (one; 0.6%), and Lutzomyia monticula (Costa Lima) (one; 0.6%). The finding of potential and incriminated vectors naturally infected with Leishmania reinforces the need of epidemiologic surveillance in the area.

Environmental change and the dynamics of parasitic diseases in the Amazon

The Amazonian environment is changing rapidly, due to deforestation, in the short term, and, climatic change is projected to alter its forest cover, in the next few decades. These modifications to the, environment have been altering the dynamics of infectious diseases which have natural foci in the, Amazonian biome, especially in its forest. Current land use practices which are changing the, epidemiological profile of the parasitic diseases in the region are road building; logging; mining; expansion of agriculture and cattle ranching and the building of large dams. Malaria and the cutaneous, leishmaniasis are the diseases best known for their rapid changes in response to environmental, modifications. Others such as soil-transmitted helminthiases, filarial infections and toxoplasmosis, which have part of their developmental cycles in the biophysical environment, are also expected to, change rapidly. An interdisciplinary approach and an integrated, international surveillance are needed, to manage the environmentally-driven changes in the Amazonian parasitic diseases in the near future.

Interpopulation Variability Among Panstrongylus megistus (Hemiptera: Reduviidae) from Brazil

Abstract Comparisons were made among Panstrongylus megistus (Burmeister) from three areas of Brazil (Bahia, Minas Gerais, and Santa Catarina), where populations differ with regard to their degree of association with human dwellings. The following characters were studied: morphology of the eggs and the male genitalia; morphometry of the head and thorax; isoenzyme profile; enzymatic activity of the ∝-glycerophosphate dehydrogenase (∝-GPDH); and cytogenetics. In general, differences were observed in the weight, diameter, and length of the egg among Bahia, Minas Gerais, and Santa Catarina populations. Differences were not observed in the architecture of the egg exochorion. The size of the median process of the pygophore of the male genitalia of individuals from Bahia differed from the other two populations. The Minas Gerais population presented the largest number of denticles in the endosome process. The morphometry of the head and thorax differentiated Santa Catarina from the Bahia and Minas Gerais populations. Phosphoglucomutase (EC 5.4.2.2., PGM) was the only enzyme out of 11 that showed polymorphism; the population from Minas Gerais was most polymorphic, whereas the population from Santa Catarina was monomorphic. Study of the ∝-GPDH activity and cytogenetics did not reveal differences among the three populations. Analysis of all the characters studied together with information on these three populations from previous publications allowed a phenogram to be constructed. Two distinct groups were evident, one represented by Santa Catarina and the other by Bahia and Minas Gerais. Considering the greater variability of the Minas Gerais and Bahia populations, we propose the inclusion of these states within the area of origin of P. megistus.

Genetic Variability in Geographical Populations of Lutzomyia whitmani Elucidated by RAPD-PCR

Abstract Unequivocal identification of phlebotomine sand flies is of crucial importance in epidemiological studies of leishmaniasis, because certain species may act as vectors, depending on behavior and physiology. For Lutzomyia whitmani, a major vector of American human cutaneous leishmaniasis in Brazil, an increasing number of studies have suggested the existence of a species complex. In the present work, we evaluated the genetic variability of L. whitmani populations from four Brazilian foci of that disease: Corte de Pedra, Ilhéus, Martinho Campos, and Serra de Baturité. Computational analysis of 85 characters, generated by RAPD-polymerase chain reaction, demonstrated high intrapopulational variability. Those characters led to sex discrimination in three of the populations, with the exception of Martinho Campos individuals, in which sex distinction was not complete. One and two interpopulational phenograms were obtained for females and males, respectively. A higher similarity was observed among the specimens from Ilhéus, Corte de Pedra, and Serra de Baturité, whereas the Martinho Campos population remained external to that cluster. These results, which are in partial accordance with a previous morphometric survey of L. whitmani from the same regions, provide additional evidence to support the existence of at least two spatial clusters of biogeographical populations of L. whitmani in Brazil.

Differential Midgut Attachment of Leishmania (Viannia) braziliensis in the Sand Flies Lutzomyia (Nyssomyia) whitmani and Lutzomyia (Nyssomyia) intermedia

The interaction between Leishmania and sand flies has been demonstrated in many Old and New World species. Besides the morphological differentiation from procyclic to infective metacyclic promastigotes, the parasite undergoes biochemical transformations in its major surface lipophosphoglycan (LPG). An upregulation of β-glucose residues was previously shown in the LPG repeat units from procyclic to metacyclic phase in Leishmania (Viannia) braziliensis, which has not been reported in any Leishmania species. LPG has been implicated as an adhesion molecule that mediates the interaction with the midgut epithelium of the sand fly in the Subgenus Leishmania. These adaptations were explored for the first time in a species from the Subgenus Viannia, L. (V.) braziliensis with its natural vectors Lutzomyia (Nyssomyia) intermedia and Lutzomyia (Nyssomyia) whitmani. Using two in vitro binding techniques, phosphoglycans (PGs) derived from procyclic and metacyclic parasites were able to bind to the insect midgut and inhibit L. braziliensis attachment. Interestingly, L. braziliensis procyclic parasite attachment was ∼11-fold greater in the midgut of L. whitmani than in L. intermedia. The epidemiological relevance of L. whitmani as a vector of American Cutaneous Leishmaniasis (ACL) in Brazil is discussed.

Evaluation of 4 polymerase chain reaction protocols for cultured Leishmania spp. typing

Leishmaniasis is a disease caused by the protozoan Leishmania resulting in a variety of clinical manifestations, from self-healing skin lesions to fatal visceral disease. The development of polymerase chain reaction (PCR)-based techniques has made species identification easier, faster, and less labor intensive. The main targets for PCR amplification include kinetoplastid DNA (kDNA), miniexon, and conserved regions such as the internal transcribed spacer. The objective of this work was to evaluate 4 different PCR techniques designed to type Leishmania using laboratory strains. Parasites were subjected to 4 PCR procedures using specific Leishmania primers for miniexon (designated A1 and A2) and kDNA (designated B1 and B2, C1 and C2, and D1, D2 and D3). Discrimination between some species and the 2 main subgenera Leishmania and Viannia was achieved. Unweighted pair group method analysis resulted in the expected clustering of the 2 species from the subgenus Leishmania. However, some species in the subgenus Viannia could not be distinguished, representing a continued challenge for PCR-based protocols. Results are discussed in terms of advantages, limitations, and reproducibility of these 4 PCR-based techniques in the taxonomy of Leishmania.

Variations of the External Male Genitalia in Three Populations of Triatoma infestans Klug, 1834

Triatoma infestans is the triatomine that presents the greatest dispersion area in South America. However, it is not known whether the original characteristics of this insect remained in its long dispersion process. The purpose of this work was to study comparatively the external male genitalia of insects from different populations of T. infestans, two from Brazil (Minas Gerais and Bahia) and one from Bolivia (Cochabamba Valley), and to investigate the correlation between the morphological and behavioral variations. Differences were observed in one of the structures of the external genitalia (endosoma process) that could be used to characterize the insects from the three populations studied.

Epidemiologic aspects of toxoplasmosis and evaluation of its seroprevalence in pregnant women

INTRODUCTION The aim of the present study was to analyze the exposure to risk factors for toxoplasmosis disease and the level of knowledge in pregnant women who were treated by the Public Health Care System (SUS) from October 2007 to September 2008 in Divinópolis City, Brazil. METHODS We analyzed 2,136 prenatal exams of pregnant women that were treated from October 2007 to September 2008. RESULTS Out of the 2,136 pregnant women evaluated, 200 answered a quantitative questionnaire; 49.5% were seropositive for immunoglobulin (Ig) G and 3.6% for IgM. Comparative analysis of congenital toxoplasmosis cases were evaluated in 11 regions and showed an irregular distribution (p < 0.01). This difference was also observed among the pregnant women observed in each location. The results from the questionnaire show that 93% of the pregnant women had no knowledge about toxoplasmosis, and 24% presented with positive serology, but no clinical manifestation. Analysis for pregnant IgG-positive women and the presence of pets showed a statistically significant correlation (p < 0.05), suggesting that the transmission of this disease might occur in the domestic environment. CONCLUSIONS We suggest the implementation of a triage program for pregnant women and health education to encourage their use of SUS services.

Public Knowledge about and Detection of Canine Visceral Leishmaniasis in Urban Divinópolis, Brazil.

Background. Leishmaniases are diseases with a wide spectrum of clinical manifestations including cutaneous (CL) and visceral (VL) forms. Many factors may affect their occurrence and expansion including environmental, geographic, and social conditions. In the past two decades, Divinópolis, Minas Gerais State, Brazil, has exhibited the potential for a disease outbreak, with the appearance of CL, and VL cases (human and canine). Hence, this study was initiated to monitor public knowledge of the disease. Questionnaires were administered in four neighborhoods (Jardim Belvedere, Esplanada, Danilo Passos I and II) where most of the human and canine cases have been reported. The analyses demonstrated that public knowledge of the disease is sparse and fragmented. A strong perception of the dog as the main reservoir was observed. Five veterinary clinics were evaluated for the presence of canine VL using serological (RIFI and ELISA) and molecular (PCR-RFLP) techniques. This is the first study demonstrating the occurrence of Leishmania infantum in Divinópolis, suggesting a possible urbanization of VL.