No abstract

Different molecular markers have been employed for typing Trypanosoma cruzi strains from endemic areas of Chagas disease. The low-stringency single specific primer-polymerase chain reaction (LSSP-PCR) has been a sensitive and informative technique that uses the variable region of kinetoplast DNA minicircles as a genetic marker, allowing detection of DNA sequence variation. In the present study, we analyzed the intra-lineage genetic variability of the T. cruzi strains obtained from triatomine feces collected on filter paper FTA card by LSSP-PCR. The hybridization of the PCR products with a probe for the subgenus Schizotrypanum and a clone-specific probe from Dm28c confirmed the subgenus as T. (S.) cruzi and respective lineages as T. cruzi I. Phenetic analysis showed the presence of three clusters that diverged by different coefficients of similarity. Thirteen T. cruzi I genotypes were observed circulating among Triatoma pseudomaculata and Rhodnius nasutus from peridomiciliary and natural environments in five peri-urban and urban localities of Jaguaruana, Ceará, Brazil. These data indicate the importance of the circulation of T. cruzi I genotypes among T. pseudomaculata and R. nasutus in different environments and the possible risk of Chagas disease domestic transmission.

In the past few years, new aspects of the immunopathology of Chagas

A survey for canine tegumentary leishmaniasis (CTL) has been carried out between 1986 and 1993 in seven endemic localities for American cutaneous leishmaniasis in the State of Rio de Janeiro. 270 dogs have been examined for their clinical aspects, the development of delayed hypersensitivity (DHS) with Immunoleish antigen and with immunofluorescent antibody research of IgG (IF). 28.2% of them had ulcer lesions and 3.3% had scars. The lesions consisted of single (39.5%) and mucocutaneous lesions (31.6%), multiple cutaneous (25.0%) and mucocutaneous lesions associated with cutaneous ulcers (4.0%). Twelve (15.8%) isolates from biopsies were analyzed by zimodeme and schizodeme and identified as L. (V.) braziliensis. The overall prevalence of canine infection that was evaluated with the skin test was of 40.5% and with IF it was of 25.5%. Both tests showed a high positive rate with relation to the animals with mucosal lesions, as in the case of human mucocutaneous leishmaniasis. The comparison of the two tests showed the skin test to have a better performance although there was no statistical difference (p>0.05) between them. The proportional sensitivity and specificity was of 84.0% and 74.0%, respectively. The Immunoleish skin test and IF are useful tools to be employed in CTL field epidemiological surveys.
Um inquérito epidemiológico em população canina foi realizado em 7 localidades endêmicas de Leishmaniose Tegumentar Americana (LTA) entre os anos de 1986 a 1993, no Estado do Rio de Janeiro. Duzentos e setenta cães foram examinados, segundo os parâmetros: clínicos, desenvolvimento de hipersensibilidade tardia e dosagem de anticorpos por imunofluorescência indireta (IFI). 28,2% dos animais possuíam lesões e 3,3% eram portadores de cicatrizes compatíveis com infecção prévia de Leishmania sp. De um total de 98 lesões ulceradas detectadas, 39,5% eram cutâneas únicas, 25,0% lesões cutâneas múltiplas, 31,6% lesões de mucosa e 4,0% lesões de mucosa associadas a lesões cutâneas. Doze amostras (15,8%) colhidas de fragmentos de lesões cutâneas foram analisadas por zimodema e esquizodema e identificadas como Leishmania (V.) braziliensis . A prevalência da infecção canina avaliada pelo teste cutâneo e pela IFI foram respectivamente de 40,5% e 25,5%. A comparação entre as reações mostrou que o teste cutâneo foi superior na detecção da infecção e da doença canina, embora, sem diferença estatística significante (p> 0,05). A sensibilidade e a especificidade proporcional foram respectivamente de 84,0% e 74,0%. A utilização de ambas as reações, cutânea e sorológica mostraram-se úteis como instrumento de diagnóstico epidemiológico em áreas de LTC

Eighteen Trypanosoma cruzi strains isolated from naturally infected triatomines were studied genetically. The majority of the strains were from Triatoma brasiliensis, the principal vector of Chagas disease in the northeast of Brazil. Multilocus enzyme electrophoresis (MLEE) and randomly amplified polymorphic DNA (RAPD) analyses were used to investigate the genotypic diversity and the spread of the T. cruzi genotypes in different environments. MLEE clearly distinguished two distinct isoenzyme profiles, and RAPD analysis revealed 10 different genotypes circulating in rural areas. The strains could be typed as isoenzyme variants of the T. cruzi principal zymodeme Z1 (T. cruzi I). An effective program of epidemiological vigilance is required to prevent the spread of T. cruzi I strains into human dwellings.

No abstract

Twenty five adult dogs of three municipalities of the State of Rio de Janeiro, Brazil, that had been naturally infected by L. (V) braziliensis were treated with N-methylglucamine antimonate (Glucantime). Nine of the animals (36.0%) presented ulcerated skin lesions, twelve (48.0%) had mucosal lesions and four (16.0%) had multiple lesions. In some cases the mucosal lesions were associated to skin lesions. A dose of 85 mg SbV+ or 1 ml of the drug was intralesionally administered to the dogs. The animals were divided into three groups according to the amount of necessary doses (between one and three) for the complete healing of the lesions. The dogs were observed for six months after the third group received the last dose. Within this period two animals perished. Serial antibody evaluation through IFAT has shown that in 14 samples (63.3%) the titers have remained unaltered, in four of them (16%) there has been a decrease in two titers and in five of them (21%) serology was negative. Nineteen of the dogs (86.6%) had their lesions completely healed. The authors suggest intralesional therapy be the first choice of treatment of canine tegumentary leishmaniasis due to its effectiveness.

Background: Recently new aspects of the immunopathology of Chagas disease have been described in patients infected with HIV and unusual clinical manifestations such as cutaneous lesions, involvement of central nervous system and/or serious cardiac lesions related to the reactivation of the parasite have been reported. Two uncloned Trypanosoma cruzi strains previously isolated from chronic chagasic patients with HIV co-infection were studied in order to evaluate the impact of the immunosuppression on the genetic diversity of the parasite.