Cor Jesus Fernandes Fontes

A expansão da epidemia da leishmaniose visceral no Estado de Mato Grosso, 1998-2005

An epidemic of visceral leishmaniasis began in 1998, in the Metropolitan Region of Cuiaba, the capital of the State of Mato Grosso, Brazil. Today, it has reached 34 (24.1%) of the 141 municipalities in the state. Between January 1998 and December 2005, 138 autochthonous cases were notified, mainly in males (58%), children aged 0-9 years (51.5%) and inhabitants of urban areas (66.7%). Canine visceral leishmaniasis has been detected in 41 municipalities, with positive serum in 9% of the 40,000 dogs examined. Lutzomyia longipalpis and/or Lutzomyia cruzi were captured in 14 out of the 18 municipalities that simultaneously recorded both human and canine visceral leishmaniasis. These findings indicate that visceral leishmaniasis transmission has become disseminated throughout the state, following migratory flows and the process of disorderly occupation of urban areas. The presence of Lutzomyia cruzi alone in areas with high incidence of human and canine cases suggests possible participation by this species in the transmission chain for visceral leishmaniasis in Mato Grosso.

Prevalence of Helicobacter pylori Infection in a Rural Area of the State of Mato Grosso, Brazil

The prevalence of Helicobacter pylori infection was evaluated by ELISA in 40 children and teenagers and in 164 adults from a rural area of the State of Mato Grosso, Brazil. Antibodies to H. pylori were detected in the serum of 31 (77.5%0 children and teenagers and in 139 (84.7%) adults. The prevalence of infection increased with age (x2 for trend, p < 0.01) even though no variations occurred in the region in the present century in terms of living conditions or sanitation, economical development and migratory influx supporting the hypothesis that the infection is also acquired during later life in developing countries. An inverse correlation was observed between the prevalence of infection and annual family income (x2 for trend, p < 0.013). There was no correlation between type of system for sewage disposal and prevalence of infection (p = 0.8). In conclusion, the prevalence of H. pylori infection in Nossa Senhora do Livramento, a rural area from Brazil, is very high and similar to that observed in other developing countries. Furthermore, the increase in the prevalence of infection with age observed in this population seems to be due to both, cohort effect and acquisition of the infection during later life.

Augmented plasma microparticles during acute Plasmodium vivax infection

BackgroundIn the last few years, the study of microparticles (MPs) - submicron vesicles released from cells upon activation or apoptosis - has gained growing interest in the field of inflammation and in infectious diseases. Their role in the human malaria parasite Plasmodium vivax remains unexplored. Because acute vivax malaria has been related to pro-inflammatory responses, the main hypothesis investigated in this study was that Plasmodium vivax infection is associated with elevated levels of circulating MPs, which may play a role during acute disease in non-immune patients.MethodsPlasma MPs were analysed among thirty-seven uncomplicated P. vivax infections from an area of unstable malaria transmission in the Brazilian Amazon. The MP phenotype was analysed by flow cytometry using the classical MP marker, annexin, and fluorochrome-labeled monoclonal antibodies against specific cell surface markers. The frequencies of plasma MPs in P. vivax patients (n = 37) were further compared to malaria-unexposed controls (n = 15) and ovarian carcinoma patients (n = 12), a known MPs-inducing disease non-related to malaria.ResultsThe frequencies of plasma circulating MPs were markedly increased in P. vivax patients, as compared to healthy age-matched malaria-unexposed controls. Although platelets, erythrocytes and leukocytes were the main cellular sources of MPs during vivax malaria, platelet derived-MPs (PMPs) increased in a linear fashion with the presence of fever at the time of blood collection (β = 0.06, p < 0.0001) and length of acute symptoms (β = 0.36, p < 0.0001). Finally, the results suggest that plasma levels of PMPs diminish as patient experience more episodes of clinical malaria (β = 0.07, p < 0.003).ConclusionsAbundant circulating MPs are present during acute P. vivax infection, and platelet derived-MPs may play a role on the acute inflammatory symptoms of malaria vivax.

Mutations in Plasmodium falciparum dihydrofolate reductase and dihydropteroate synthase of isolates from the Amazon Region of Brazil

Since the late 1970s pyrimethamine-sulfadoxine (PS; FansidarTM Hoffman-LaRoche, Basel) has been used as first line therapy for uncomplicated malaria in the Amazon basin. Unfortunately, resistance has developed over the last ten years in many regions of the Amazon and PS is no longer recommended for use in Brazil. In vitro resistance to pyrimethamine and cycloguanil (the active metabolite of proguanil) is caused by specific point mutations in Plasmodium falciparum dihydrofolate reductase (DHFR), and in vitro resistance to sulfadoxine has been associated with mutations in dihydropteroate synthase (DHPS). In association with a proguanil-sulfamethoxazole clinical trial in Brazil, we performed a nested mutation-specific polymerase chain reaction to measure the prevalence of DHFR mutations at codons 50, 51, 59, 108 and 164 and DHPS mutations at codons 436, 437, 540, 581 and 613 at three sites in the Brazilian Amazon. Samples from two isolated towns showed a high degree of homogeneity, with the DHFR Arg-50/Ile-51/Asn-108 and DHPS Gly-437/Glu-540/Gly-581 mutant genotype accounting for all infections in Peixoto de Azevedo (n = 15) and 60% of infections in Apiacás (n = 10), State of Mato Grosso. The remaining infections in Apiacás differed from this predominant genotype only by the addition of the Bolivia repeat at codon 30 and the Leu-164 mutation in DHFR. By contrast, 17 samples from Porto Velho, capital city of the State of Rondônia, with much in- and out-migration, showed a wide variety of DHFR and DHPS genotypes.

Is the geographical origin of a Paracoccidioides brasiliensis isolate important for antigen production for regional diagnosis of paracoccidioidomycosis

In this study, exoantigens produced from two Paracoccidioides brasiliensis strains isolated in two different geographical areas were compared in terms of sensitivity and specificity in relation to paracoccidioidomycosis (PCM) diagnosis. Exoantigens from P. brasiliensis 550B (Ag 550B) isolated in the central‐west region of Brazil (Mato Grosso State) and exoantigen produced from P. brasiliensis B‐339 (Ag B‐339) used in reference laboratories were compared by immunodiffusion (ID) tests. When Ag 550B was used in ID test against sera of patients from Mato Grosso and São Paulo, positivity was 92.3% and 41.3%, respectively. On the other hand, when Ag B‐339 was tested with the same sera, positivity was 26.2% and 100%, respectively. These results suggest that differences in the antigenic composition probably related to phylogenetic peculiarities in P. brasiliensis isolates from the central‐western region of Brazil should be considered in the diagnosis of PCM.

Fatores associados ao insucesso do tratamento da leishmaniose cutânea com antimoniato de meglumina

We investigated factors associated with treatment failure in the treatment of cutaneous leishmaniasis with meglumine antimony in a reference service in Mato Grosso State. A retrospective cohort of 151 patients with cutaneous leishmaniasis was built using medical records. The incidence of therapeutic failure was 47% (IC95%=39.2%-55%). Antimoniate doses below 10mg/kg/day (RR=1.8; IC95:1.1-3.0), previous leishmaniasis treatment (RR=1.7; IC95:1.3-2.4), 3 or more skin lesions (RR=1.9; IC95:1.4-2.5), incomplete treatment (RR=1.9; IC95:1.3-2.6) and body weight above 68kg (RR=1.7; IC95:1.1-2.5) were associated with therapeutic failure. After adjustment, therapeutic failure was associated with having 3 or more cutaneous lesions (OR=4.6; IC95%=1.2-17.4), reports of previous leishmaniasis treatment (OR=4.5; IC95%=1.1-17.5), body weight above 68kg (OR=4.3; IC95=1.5-11.9) and incomplete treatment schedule (OR=12.5; IC95%=2.1-75.4), although body weight is possibly associated with treatment failure due to the limitation of the maximum daily dose. These results help to identify patients at risk of treatment failure of cutaneous leishmaniasis with antimony therapy.

Randomly amplified polymorphic DNA as a valuable tool for epidemiological studies of Paracoccidioides brasiliensis.

ABSTRACT Randomly amplified polymorphic DNA (RAPD) has been successfully used to detect genetic variations among isolates of Paracoccidioides brasiliensis. However, the usefulness of this technique for assessing important parasitic properties is still unconfirmed. In the present work we further investigated the applicability of RAPD in revealing important intrinsic and extrinsic features of this fungus associated with geographical origin, time of isolation, source of clinical specimen, clinical forms of human disease and also in vitro and in vivo susceptibility to antimicrobial and antifungal drugs. The RAPD patterns allowed us to distinguish all of the analyzed strains, which included 26 clinical isolates, 2 animal isolates, and 1 environmental isolate of P. brasiliensis obtained from different geographic regions, confirming the strong discriminating power of this technique. A phenetic tree, build from the RAPD data, showed that although the two nonclinical Brazilian strains were set together the majority of the clinical Brazilian strains were randomly distributed through different sub-branches of a major cluster without any correlation to any of the parameters analyzed. A second major cluster, however, has grouped isolates from Mato Grosso and Roraima (Brazil) that not only were susceptible in vitro to trimethoprim-sulfamethoxazole but also produced a good in vivo response. These results open new vistas for epidemiological and clinical studies of P. brasiliensis.

Inhibitory Properties of the Antibody Response to Plasmodium vivax Duffy Binding Protein in an Area with Unstable Malaria Transmission

The function of the Plasmodium vivax Duffy binding protein (DBP) during the erythrocyte invasion process is critical for successful parasite growth and pathogenesis in human infections. Although DBP is the subject of intensive malaria vaccine research, investigations on the functional proprieties of anti‐DBP antibodies in the human population have been limited [Infect Immun68 (2000) 3164]. In the present study, we examined the ability of sera from different populations of the Brazilian Amazon – an area of markedly unstable malaria transmission – to inhibit the erythrocyte‐binding function of the DBP ligand domain (region II, DBPII). We found that long‐term exposure to malaria in the Amazon area elicits DBP‐specific antibodies that inhibit the binding of different DBPII variants to erythrocytes. Despite the great variability of inhibitory antibody responses observed among study participants, we observed a positive correlation between erythrocyte binding‐inhibitory activity and enzyme‐linked immunosorbent assay anti‐DBP antibodies. Of importance, there was a non‐significant tendency towards increased levels of anti‐DBP antibodies among individuals with asymptomatic P. vivax infections.

Microsatellite loci: determining the genetic variability of Plasmodium vivax.

Objective  To describe the genetic diversity of Plasmodium vivax isolates from different areas in the Brazilian Amazon using 11 polymorphic microsatellites and to evaluate the correlation between microsatellite variation and repeat array length.

Prevalência da infecção pelos vírus das hepatites A e E em escolares de município da Amazônia Matogrossense

The prevalence of antibodies to hepatitis A anti-HAV total and E viruses anti-HEV IgG was assessed in 487 children ranging from 2 to 9 years old who were students of nurseries and public schools in a county of the Amazonian region, in Mato Grosso State, Brazil. The anti-HAV and anti-HEV prevalence were 86.4% (CI 95% 83 ¾ 89.3) and 4.5% (CI95% 2.9 ¾ 6.9), respectively. The anti-HAV prevalence was high in all ages, suggesting that this is an area of high endemicity for HAV infection. There was no association between the anti-HAV markers and gender, socioeconomic level, parental educational level, hygienic conditions, number or density of residents per room or schools in which they studied. Anti-HEV prevalence was low and similar to that found among adults in another Brazilian regions.