Carlos Eurico dos Santos Fernandes

Biotic factors and occurrence of Lutzomyia longipalpis in endemic area of visceral leishmaniasis, Mato Grosso do Sul, Brazil

The relationships between environmental exposure to risk agents and health conditions have been studied with the aid of remote sensing imagery, a tool particularly useful in the study of vegetation cover. This study aims to evaluate the influence of environmental variables on the spatial distribution of the abundance of Lutzomyia longipalpis and the reported canine and human visceral leishmaniasis (VL) cases at an urban area of Campo Grande, state of Mato Grosso do Sul. The sandfly captures were performed in 13 residences that were selected by raffle considering four residences or collection station for buffer. These buffers were generated from the central house with about 50, 100 and 200 m from it in an endemic area of VL. The abundance of sandflies and human and canine cases were georreferenced using the GIS software PCI Geomatica. The normalized difference vegetation index (NDVI) and percentage of land covered by vegetation were the environmental variables extracted from a remote sensing IKONOS-2 image. The average NDVI was considered as the complexity of habitat and the standard deviation as the heterogeneity of habitat. One thousand three hundred sixty-seven specimens were collected during the catch. We found a significant positive linear correlation between the abundance of sandflies and the percentage of vegetation cover and average NDVI. However, there was no significant association between habitat heterogeneity and the abundance of these flies.

Genetic structure of Lutzomyia longipalpis populations in Mato Grosso Do Sul, Brazil, based on microsatellite markers.

Background Lutzomyia longipalpis (Diptera: Psychodidae) is the major vector of Leishmania (Leishmania) infantum and thus plays a crucial role in the epidemiology of American visceral leishmaniasis (AVL). This vector is the best studied species of sand fly in the Neotropical region. Many studies claim that this vector is in fact a species complex; however there is still no consensus regarding the number of species that belong into this complex or the geographical distribution of sibling species. The aim of the present study was to analyze the genetic relationships within Lu. longipalpis populations in the state of Mato Grosso do Sul (MS), Brazil. Methodology/Principal Findings We collected 30 Lu. longipalpis (15 females and 15 males) from five localities (Campo Grande, Três Lagoas, Aquidauana, Miranda and Bonito) and 30 Lu. Cruzi from Corumbá, totaling 180 sandflies from MS, and 30 Lu. longipalpis from Estrela de Alagoas, state of Alagoas (AL), Northeast Brazil. We show that eight previously described microsatellite loci were sufficient in distinguishing Lu. longipalpis from Lu. Cruzi, which is a closely related species, and in differentiating between Lu. longipalpis collected in MS versus Estrela de Alagoas. Analyses of the genotypes revealed introgression between sympatric Lu. longipalpis and Lu. Cruzi. Conclusions/Significance Our findings support the hypothesis of cryptic species within the Lu. longipalpis complex. Furthermore, our data revealed introgression between Lu. longipalpis and Lu. cruzi. This phenomenon should be further investigated to determine the level and incidence of hybridization between these two species. We also demonstrated that microsatellite markers are a powerful tool for differentiating sand fly populations and species. The present study has elucidated the population structure of Lu. longipalpis in MS and, by extension, the Neotropical Lu. longipalpis complex itself.

Observations on the feeding habits of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae: Phlebotominae) in Campo Grande, an endemic area of visceral leishmaniasis in Mato Grosso do Sul, Brazil

Sand flies were captured weekly with CDC light traps from December 2003 to November 2005 in three areas of Campo Grande, in the Brazilian state of Mato Grosso do Sul. These areas incorporated two patches of remnant forest and five houses. The blood meals of engorged female sand flies were identified using the avidin-biotin system of immunoenzymatic ELISA capture. Most (327/355) of the females analysed were Lutzomyia longipalpis, of which 66.4% reacted with human blood, 64.8% with that of birds and 8.9% with that of dogs. Females that had taken human blood predominated in the residential areas and two forest patches. The following combinations of blood were also detected for L. longipalpis in some of the samples analysed: bird+human (43.4%), bird+human+dog (6.1%). The combination bird+human+dog+pig was also found for Nyssomyia whitmani. Dogs and pigs appear to have little attractiveness for L. longipalpis. The results obtained demonstrate the eclecticism and high anthropophily of L. longipalpis and raise new questions with regard to the importance of dogs in VL epidemiology and the possible role of man as a source of infection for sand flies.

Local immunosuppression induced by high viral load of human papillomavirus: characterization of cellular phenotypes producing interleukin‐10 in cervical neoplastic lesions

A specific immune response to human papillomavirus (HPV) in the cervical microenvironment plays a key role in eradicating infection and eliminating mutated cells. However, high‐risk HPVs modulate immune cells to create an immunosuppressive microenvironment, and induce these immune cells to produce interleukin 10 (IL‐10). This production of IL‐10, in conjunction with HPV infection, contributes to the appearance of cervical neoplastic lesions. We sought to characterize the IL‐10‐producing cellular phenotype, and investigate the influence of host and HPV factors upon the induction of an immunosuppressive microenvironment. Immunohistochemical analysis demonstrated an increase in IL‐10 production by keratinocytes, macrophages and Langerhans cells in high‐grade cervical lesions and cervical cancer. This increase was more pronounced in patients older than 30 years, and was also correlated with high viral load, and infection with a single HPV type, particularly high‐risk HPVs. Our results indicate the existence of a highly immunosuppressive microenvironment composed of different IL‐10‐producing cellular phenotypes in cervical cancer samples, and samples classified as high‐grade cervical lesions (cervical intraepithelial neoplasia stages II and III). The immunosuppressive microenvironment that developed for these different cellular phenotypes favours viral persistence and neoplastic progression.

Intoxicação por Brachiaria spp. em bovinos no Mato Grosso do Sul

The epidemiology, clinical signs and pathology of 29 outbreaks of spontaneous poisoning by Brachiaria spp. in beef cattle, which occurred from March 1996 to November 2009, in the state of Mato Grosso do Sul, were retrospectively studied. For this, the files of the Veterinary Pathology Laboratory at the Federal University of Mato Grosso do Sul were reviewed. Outbreaks occurred at different times of the year, including dry and rainy seasons. While photosensitization was the main clinical sign in cattle from 24 out of 29 outbreaks, in five of them the main clinical sign was progressive wasting, without photosensitization. Eleven outbreaks of photosensitization occurred in pastures of Brachiaria decumbens, two in mixed pastures of B. decumbens and B. brizantha, and one in B. brizantha. In 10 outbreaks the species of Brachiaria was not informed. Morbidity ranged from 0.2% to 50%, and fatality rates were between 44.4% and 100%. In cases of photosensitization brisket edema was the most frequent clinical sign observed. Dermatitis with thickened skin of the flank and perineal region, scar retraction of the ears, jaundice, ocular discharge, crusts in the eyes and ears, and ulceration of the ventral surface of the tongue were also observed. Nervous signs were observed in two cases and diarrhea in one. At necropsy the liver was enlarged, yellowish, with increased lobular pattern, and occasionally with depressed whitish areas. The kidneys were brownish and the urine dark. Upon histological examination of the liver the hepatocytes were swollen and vacuolized. Individual necrosis of hepatocytes, bile duct cell proliferation, biliary retention, and mild to moderate periportal fibrosis were also observed. In all cases foamy macrophages, most in groups, were observed mainly in the centrilobular region. In 21 cattle birefringent crystals were observed within the bile ducts. Five outbreaks of progressive wasting were observed in cattle grazing B. decumbens pastures. The main lesion was an enlarged yellowish liver. Histologic lesions were similar to those observed in cases of photosensitization. Birefringent crystals were observed in the liver of three cases, but foamy macrophages were found in all animals. It is concluded that B. decumbens is more toxic than B. brizantha and that the poisoning occurs at any time of the year. Nevertheless, research is still necessary to determine variations in the saponin content of Brachiaria species and the probable differences on susceptibility/resistance to the poisoning of cattle of different ages, breeds and from different regions.

Glucocorticoid-induced tumor necrosis factor receptor expression in patients with cervical human papillomavirus infection

INTRODUCTION The progression of human papillomavirus (HPV) infection in the anogenital tract has been associated with the involvement of cells with regulatory properties. Evidence has shown that glucocorticoid-induced tumor necrosis factor receptor (GITR) is an important surface molecule for the characterization of these cells and proposes that GITR ligand may constitute a rational treatment for many cancer types. We aimed to detect the presence of GITR and CD25 in cervical stroma cells with and without pathological changes or HPV infection to better understand the immune response in the infected tissue microenvironment. METHODS We subjected 49 paraffin-embedded cervical tissue samples to HPV DNA detection and histopathological analysis, and subsequently immunohistochemistry to detect GITR and CD25 in lymphocytes. RESULTS We observed that 76.9% of all samples with high GITR expression were HPV-positive regardless of histopathological findings. High GITR expression (77.8%) was predominant in samples with ≥ 1,000 RLU/PCB. Of the HPV-positive samples negative for intraepithelial lesion and malignancy, 62.5% had high GITR expression. High GITR expression was observed in both carcinoma and high-grade squamous intraepithelial lesion (HSIL) samples (p = 0.16). CD25 was present in great quantities in all samples. CONCLUSIONS The predominance of high GITR expression in samples with high viral load that were classified as HSIL and carcinoma suggests that GITR+ cells can exhibit regulatory properties and may contribute to the progression of HPV-induced cervical neoplasia, emphasizing the importance of GITR as a potential target for immune therapy of cervical cancer and as a disease evolution biomarker.

Climatic Factors and Population Density of Lutzomyia longipalpis (Lutz & Neiva, 1912) in an Urban Endemic Area of Visceral Leishmaniasis in Midwest Brazil

ABSTRACT: The life cycle of vectors and the reservoirs that participate in the chain of infectious diseases have a strong relationship with the environmental dynamics of the ecosystems in which they live. Oscillations in population abundance and seasonality of insects can be explained by factors inherent in each region and time period. Therefore, knowledge of the relationship and influence of environmental factors on the population of Lutzomyia longipalpis is necessary because of the high incidence of visceral leishmaniasis (VL) in Brazil. This study evaluates the influence of abiotic variables on the population density and seasonal behavior of L. longipalpis in an urban endemic area of VL in Brazil. The sand fly captures were performed every two months between November, 2009 and November, 2010 in the peridomicile of 13 randomly selected residences. We captured 1,367 specimens of L. longipalpis, and the ratio of male/female flies was 2.86:1. The comparison of the total male specimens in the two seasons showed a statistical difference in the wet season, but there was no significant difference when considering the total females. With respect to climatic variables, a significant negative association was observed only with wind speed. During periods of high wind speeds, the population density of this vector decreased. The presence of L. longipalpis was found in all months of the study with bimodal behavior and population peaks during the wet season.

Presença de formas amastigotas de Leishmania chagasi e perfil leucocitário no aparelho reprodutivo de cães

Visceral leishmaniasis (VL) is a zoonosis caused by Leishmania (Leishmania) chagasi. Canine visceral leishmaniasis (VLC) is most important. The infection occurs usually between the invertebrate host and vertebrate host; however, transmission in the absence of the vector has been reported. The aim of this study was to identify the presence of amastigote forms, quantify the leucocyte cells and to estimate the presence (odds ratio) of the amastigotes in the reproductive tract of dogs serologically positive with and without clinical signs. Sexually mature Mongrel dogs, serologically tested to VLC (symptomatic, n=25; asymptomatic, n=25), were used. After euthanasia, testes, epidydimal (caput, corpus and cauda) and prostate gland fragments (randomized) were recovered and impressed on slides. Twenty animals serologically negative and asymptomatic were used as control group. Samples of spleen were included as parasitological positive controls. Lymphocyte percentages were higher (P<0.05) in the corpus and caudal region of epididymis, similar to the testes in the symptomatic group. Macrophage percentage was higher (P<0.05) in the corpus and caudal epididymis regions. The presence of amastigote forms was associated with different regions of the reproductive tract. In the symptomatic group, the variation was between 0.50 and 0.80, and in the symptomatic between 0.79 and 0.95. The odds ratio for amastigote forms in the testicle of the symptomatic dogs was 6.5 in relation to asymptomatic dogs. The results demonstrate the epidemic potential of venereal transmission of the disease, specifically in areas where control programs of VLC do not consider this transmission route.

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

ABSTRACT 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).

High Prevalence of HTLV-1 Infection among Japanese Immigrants in Non-endemic Area of Brazil

Background Human T-lymphotropic virus type 1 (HTLV-1) has worldwide distribution and is considered endemic in many world regions, including southwestern Japan and Brazil. Japanese immigrants and their descendants have a high risk of acquiring this infection due to intense population exchange between Brazil and Japan. Objective This cross-sectional study aimed to estimate the prevalence of HTLV, analyze the main risk factors associated with this infection, identify the main circulating types and subtypes of HTLV in Japanese immigrants and descendants living in Campo Grande-MS (Middle-West Brazil), as well as analyze the phylogenetic relationship among isolates of HTLV. Study Design A total of 219 individuals were interviewed and submitted to blood collection. All collected blood samples were submitted for detection of anti-HTLV-1/2 using the immunoassay ELISA and confirmed by immunoblot method. The proviral DNA of the 14 samples HTLV- 1 positive were genotyped by nucleotide sequencing. Results The overall prevalence of HTLV-1 was 6.8% (IC 95%: 3,5-10,2). Descriptive analysis of behavioral risk factors showed statistical association between HTLV-1 and age greater than or equal to 45 years. The proviral DNA of HTLV-1 was detected in all HTLV-1 positive samples. Of these, 14 were sequenced and classified as Cosmopolitan subtype, and 50% (7/14) belonged to subgroup A (transcontinental) and 50% (7/14) to the subgroup B (Japanese). Conclusion The high prevalence of HTLV-1 found evidence of the importance of early diagnosis and counseling of individuals infected with HTLV-1 for the control and prevention of the spread of this infection among Japanese immigrants and their descendants in Central Brazil.