The subclinical form of experimental visceral leishmaniasis in dogs

Pathological aspects of a subclinical form of experimental canine leishmaniasis is reported here for the first time. Fifteen mongrel dogs were used in the present study. Eight dogs were infected and seven were used as control. Four of the control dogs were inoculated with spleen cells from non-infected hamsters. The eight mongrel dogs inoculated intravenously with amastigotes forms of Leishmania chagasi envolved for periods as long as 25 months without any clinical characteristic sign of classical Visceral Leishmaniasis (VL). Most of the laboratory test results were compatible to those of the seven control animals but culture of bone marrow aspirated material and serologic testing (IIF) demonstrated or provided evidence that the animals were infected. The most important and predominant histopathological lesion in infected animals were epitheloid granulomas presented in the liver, spleen, adrenal gland and lung of some animals. Channels containing erythrocytes in some granulomas of the liver suggeste that these granulomas are formed inside sinusoidal capillaries. Despite the animals were proved to be infected and presented characteristic histologic lesions, they did not present external signs of disease. The granulomatous aspect of the lesions indicates a good immunologic reactivity and suggest that a host-parasite equilibrium does exist in the dog experimental model

Subclinical form of the American visceral leishmaniasis

The subclinical form of visceral leishmaniasis (VL) shows nonspecific clinical manifestations, with difficulties being frequently met in its clinical characterization and diagnostic confirmation. Thus, the objective of the present study was to define the clinical-laboratory profile of this clinical form. A cohort study was conducted in the state of Maranhão, Brazil, from January/1998 to December/2000, with monthly follow-up of 784 children aged 0-5 years. Based on the clinical-laboratory parameters reported in the literature, four categories were established, with the children being classified (according to their clinical-evolutive behavior) as asymptomatic (N = 144), as having the subclinical form (N = 33) or the acute form (N = 12) or as subjects "without VL" (N = 595). Multiple discriminant analysis demonstrated that the combination of fever, hepatomegaly, hyperglobulinemia, and increased blood sedimentation rate (BSR) can predict the subclinical form of VL as long as it is not associated with splenomegaly or leukopenia. Subjects with the subclinical form did not show prolonged or intermittent evolution or progression to the acute form of VL. Subclinical cases have a profile differing from the remaining clinical forms of VL, being best characterized by the combination of fever, hepatomegaly, hyperglobulinemia, and increased BSR.

Serum cytokine profile in the subclinical form of visceral leishmaniasis

The factors determining the development or not of visceral leishmaniasis (VL) have not been completely identified, but a Leishmania-specific cellular immune response seems to play a fundamental role in the final control of infection. Few studies are available regarding the production of cytokines in the subclinical form of VL, with only the production of IFN-g and TNF-a known. The aim of the present study was to identify immunological markers for the oligosymptomatic or subclinical form of VL. A prospective cohort study was conducted on 784 children aged 0 to 5 years from an endemic area in the State of Maranhão, Brazil, between January 1998 and December 2001. During 30 consecutive months of follow-up, 33 children developed the oligosymptomatic form of the disease and 12 the acute form. During the clinical manifestations, serum cytokine levels were determined in 27 oligosymptomatic children and in nine patients with the acute form using a quantitative sandwich enzyme immunoassay. In the subclinical form of VL, variable levels of IL-2 were detected in 52.3% of the children, IL-12 in 85.2%, IFN-g in 48.1%, IL-10 in 88.9%, and TNF-a in 100.0%, with the last two cytokines showing significantly lower levels than in the acute form. IL-4 was not detected in oligosymptomatic individuals. Multiple discriminant analysis used to determine the profile or combination of cytokines predominating in the subclinical form revealed both a Leishmania resistance (Th1) and susceptibility (Th2) profile. The detection of both Th1 and Th2 cytokine profiles explains the self-limited evolution accompanied by the discrete alterations observed for the subclinical form of VL.

Toxoplasmosis and mental retardation: report of a case-control study

A case-control study evaluating the association between mental retardation and toxoplasmosis was conducted among 845 school children in Belo Horizonte, MG, Brazil. Cases (450) were mentally retarded children attending a public school for special education. Controls (395) were children from the regular public school system. Clinical and anthropometric examinations and interviews were carried out to determine risk factors for toxoplasmosis and mental retardation. Diagnosis of Toxoplasma gondii infection was based upon an indirect immunofluorescent test (IFA); 55% of cases and 29% of controls were positive. The Relative Odds of mental retardation in children with positive serology was 3.0 (95% CI 2.2-4.0). Maternal exposure to cats and contact with soil were associated with an increased risk of mental retardation. Retinochoroiditis was fourfold more prevalent among cases than controls and was only diagnosed in T. gondii IFA positive participants. Congenital toxoplasmosis, in its subclinical form, appears to be an important component in the etiology of mental retardation, especially in high risk (lower socio-economic) groups. The population attributable risk was estimated as 6.0 - 9.0%, suggesting the amount of mental retardation associated with this infection.

Western blot detection of infectious bursal disease virus infection

In order to evaluate the use of a Western blot methodology for the diagnosis of infectious bursal disease virus (IBDV) infection, chickens were experimentally infected with IBDV strains and tested for the presence of viral antigens and antibodies by a blocking Western blot test (bWB). The viral proteins obtained from the bursa of Fabricius (BF) were transferred to a nitrocellulose membrane after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the chicken sera obtained by heart puncture were used for the detection of these proteins. In order to eliminate nonspecific reactions, we used a rabbit anti-chicken serum (blocking tool). By the use of the bWB test, two distinct viral proteins of 43-kDa (VP2) and 32-kDa (VP3) were detected. We suggest the use of this methodology for the detection of IBDV infection in animals suspected of having IBDV reinfection and a chronic subclinical form of the disease. With the use of the rabbit anti-chicken sera for blocking, this method is practical, sensitive and less time consuming

Unveiling healthy carriers and subclinical infections among household contacts of leprosy patients who play potential roles in the disease chain of transmission

Leprosy transmission still occurs despite the availability of highly effective treatment. The next step towards successfully eliminating leprosy is interrupting the chain of transmission of the aetiological agent, Mycobacterium leprae. In this investigation, we provide evidence that household contacts (HHCs) of leprosy patients might not only have subclinical infections, but may also be actively involved in bacilli transmission. We studied 444 patients and 1,352 contacts using anti-phenolic glycolipid-I (PGL-I) serology and quantitative polymerase chain reaction (qPCR) to test for M. leprae DNA in nasal swabs. We classified the patients according to the clinical form of their disease and the contacts according to the characteristics of their index case. Overall, 63.3% and 34.2% of patients tested positive by ELISA and PCR, respectively. For HHCs, 13.3% had a positive ELISA test result and 4.7% had a positive PCR test result. The presence of circulating anti-PGL-I among healthy contacts (with or without a positive PCR test result from nasal swabs) was considered to indicate a subclinical infection. DNA detected in nasal swabs also indicates the presence of bacilli at the site of transmission and bacterial entrance. We suggest that the concomitant use of both assays may allow us to detect subclinical infection in HHCs and to identify possible bacilli carriers who may transmit and disseminate disease in endemic regions. Chemoprophylaxis of these contacts is suggested.

Validação para o português do "International Consultation on Incontinence Questionnaire - Short Form" (ICIQ-SF)

OBJETIVO: Traduzir e validar para a língua portuguesa o questionário de qualidade de vida condição-específico denominado International Consultation on Incontinence Questionnaire - Short Form (ICIQ-SF) em pacientes com incontinência urinária. MÉTODOS: Duas traduções independentes do ICIQ-SF foram feitas por brasileiros, fluentes na língua inglesa. Após harmonização das mesmas, a tradução resultante foi retrotraduzida independentemente por dois nativos de países de língua inglesa. As diferenças foram harmonizadas e pré-testadas em um estudo piloto. A versão final do ICIQ-SF para o português, bem como a versão em português do King's Health Questionnaire (KHQ) foram aplicadas simultaneamente em 123 pacientes consecutivos com queixa de incontinência urinária (29 homens e 94 mulheres) que procuraram o laboratório de uroginecologia e o serviço de urodinâmica de um hospital universitário, localizado em Campinas. Foram testadas as propriedades psicométricas do questionário, como confiabilidade e validade de constructo. RESULTADOS: A idade mediana foi de 53 anos (intervalo de 16 a 86 anos). O período médio de reteste para o ICIQ-SF foi de 14,37 dias (intervalo de seis a 41 dias). Nenhuma alteração do formato original do ICIQ-SF foi observada no final do processo de tradução e adaptação cultural. A consistência interna foi alta, como demonstrado pelo coeficiente alfa de Cronbach (0,88). O resultado do teste-reteste foi considerado de moderado a forte, como indicado pelo índice Kappa ponderado, cujos valores variaram de 0,72 a 0,75, e o coeficiente de correlação de Pearson que foi de 0,89. A correlação entre o ICIQ-SF e o KHQ foi considerada de moderada a boa para a maioria dos itens, variando de 0,44 a 0,77. A avaliação das validades de constructo e concorrente foi também satisfatória e estatisticamente significante. CONCLUSÕES: A versão para o português do ICIQ-SF foi traduzida e validada com sucesso para aplicação em pacientes brasileiros de ambos os sexos, com queixa de incontinência urinária, apresentando satisfatória confiabilidade e validade de constructo.

Proposal of a short-form version of the Brazilian Food Insecurity Scale

OBJECTIVE To propose a short version of the Brazilian Food Insecurity Scale. METHODS Two samples were used to test the results obtained in the analyses in two distinct scenarios. One of the studies was composed of 230 low income families from Pelotas, RS, Southern Brazil, and the other was composed of 15,575 women, whose data were obtained from the 2006 National Survey on Demography and Health. Two models were tested, the first containing seven questions, and the second, the five questions that were considered the most relevant ones in the concordance analysis. The models were compared to the Brazilian Food Insecurity Scale, and the sensitivity, specificity and accuracy parameters were calculated, as well as the kappa agreement test. RESULTS Comparing the prevalence of food insecurity between the Brazilian Food Insecurity Scale and the two models, the differences were around 2 percentage points. In the sensitivity analysis, the short version of seven questions obtained 97.8% and 99.5% in the Pelotas sample and in the National Survey on Demography and Health sample, respectively, while specificity was 100% in both studies. The five-question model showed similar results (sensitivity of 95.7% and 99.5% in the Pelotas sample and in the National Survey on Demography and Health sample, respectively). In the Pelotas sample, the kappa test of the seven-question version totaled 97.0% and that of the five-question version, 95.0%. In the National Survey on Demography and Health sample, the two models presented a 99.0% kappa. CONCLUSIONS We suggest that the model with five questions should be used as the short version of the Brazilian Food Insecurity Scale, as its results were similar to the original scale with a lower number of questions. This version needs to be administered to other populations in Brazil in order to allow for the adequate assessment of the validity parameters.

In vitro susceptibility of Paracoccidioides brasiliensis yeast form to antifungal agents

A study was conducted to determine the susceptibility of P. brasiliensis yeast form to amphotericin B (A), ketoconazole (K), 5-fluorocytosine (5-FC) and rifampin (R). The three isolates tested produced minimal inhibitory concentrations (MICs) (mcg/ml) in the following range: A: 0.09-0.18; K: 0.001-0.007; 5-FC: 62.5-250 and R: 40-80. The minimal fungicidal concentrations (MFC) were several times higher than the corresponding MICs. Precise MFC for 5-FC were not obtained (> 500 mcg/ml). Combination of K plus A proved synergic, with the fractional inhibitory concentration (FIC) indices revealing synergy when the drugs were combined at the 1 to 1 and 1 to 5 MIC ratios. R (40 mcg/ml) appeared to antagonize K. These results indicate promise for the combined use of K plus A as a therapeutical regimen.

Viscerocutaneous form of loxoscelism and erythrocyte glucose-6-phosphate deficiency

In a period of time of five years, all patients who exhibited viscerocutaneous form of loxoscelism were investigated for erythrocyte glucose-6-phosphate deficiency, and in two patients out of seven it was found this deficiency. This finding suggests that this genetical enzyme deficiency could account for the hemolysis after Loxosceles bite, at least in some of the cases.

Hypoprothrombinemia in the compensated form of hepatosplenic schistosomiasis: further studies

Coagulation abnormality is frequently observed in schistosomiasis patients but its pathophysiology has not been established. We measured, by immunodiffusion. the prothrombin-antigen concentration in 56 individuals; of these 19 with demonstrated compensated form of hepatosplenic schistosomiasis, 17 with cirrhosis and 20 were control subjects. Transaminases, albumin, transthyretin, prothrombin time, antithrombin III, factor VII, and fibrinogen were also evaluated. All parameters were altered in the cirrhotic group but only albumin, prothrombin and antithrombin III levels were altered in the schistosomiasis group. Ninety percent of the patients with cirrhosis and sixty percent of the patients with schistosomiasis had abnormal plasma levels of albumin, transthyretin, prothrombin-antigen, and/or antithrombin III; an impaired hepatic synthesis was responsible for these results. Conversely forty percent of the schistosomiasis patients with normal plasma concentrations of both albumin and transthyretin had decreased mean plasma levels of both prothrombin and antithrombin III. These results suggest that either proth rombin and antithrombin III are more sensitive markers of impaired hepatic synthesis in schistosomiasis than are levels of albumin and transthyretin combined, or a low grade chronic consumption of clotting proteins also occurs. Considering the latter hypothesis it is possible that the thrombin formed would be inhibited by antithrombin III with the complexed thrombin-antithrombin III being cleared by the liver. Consequently the plasma levels of both prothrombin and antithrombin would be decreased, but the level of fibrinogen would be preserved.

Chlamydospore formation by Paracoccidioides brasiliensis mycelial form

To investigate the role of some adverse environmental conditions in chlamy-dospore formation by the mycelial form of P. brasiliensis, we cultured four P. brasiliensis isolates (18, Bt4, 1183, Pb9) at 25°C within solid agar medium either rich or poor in nutrients. Isolates 18 and 1183 were also cultured under anaerobiosis in a nitrogen atmosphere. Isolate 18 produced great number of terminal and intercalary chlamydospore after 7-10 days of culture in a medium poor in nutrients (2% agar with 0.1% dextrose and polypepton). The three other isolates also produced chlamydospores under the same conditions, but in lower numbers. Chlamydospore production by isolate 18 was abolished when the fungus was cultured in two agar media rich in nutrients (brain heart infusion and potato dextrose agar). Anaerobic incubation of isolate 18 under an atmosphere of N2 showed small mycelial outgrowth with numerous chlamydospores. At the electron microscopical level, the chlamydospores showed one or various nuclei and numerous mitochondria, indicating great potential for further development. Accordingly, chlamydospores produced multiple budding after only 24 h incubation at 35°C. The results demonstrate that under adverse environmental conditions P. brasiliensis mycelial form produces chlamydospores within a short period of time.

Central nervous system involvement in Chagas' disease: an updating

A review was made of the available literature on central nervous system (CNS) involvement in Chagas' disease. Thirty-one works concerning the acute nervous form and 17 others dealing with the chronic nervous form, all presenting neuropathologic studies, were critically analysed. Based on this analysis, an attempt was made to establish the possible natural history of CNS involvement in Chagas' disease. Among others, the following facts stand out: 1) the initial, acute phase of Trypanosoma cruzi infection is usually asymptomatic and subclinical; 2) only a small percentage of cases develop encephalitis in the acute phase of Chagas' disease; 3) the symptomatic acute forms accompanied by chagasic encephalitis are grave, with death ensuing in virtually all cases as a result of the brain lesions per se or of acute chagasic myocarditis, this being usually intense and always present; 4) individuals with the asymptomatic acute form and with the mild symptomatic acute form probably have no CNS infection or, in some cases, they may have discrete encephalitis in sparse foci. In the latter case, regression of the lesions may be total, or residual inflammatory nodules of relative insignificance may persist. Thus, no anatomical basis exists that might characterize the existence of a chronic nervous form of Chagas' disease; 5) reactivation of the CNS infection in the chronic form of Chagas' disease is uncommon and occurs only in immunosuppressed patients.

Chronic gastritis and Helicobacter pylori in digestive form of Chagas' disease

Patients with the digestive form of Chagas'disease frequently present chronic gastritis. As the microorganism Helicobacter pylori is now accepted as the most common cause of human chronic gastritis, the present work was undertaken to verify a possible relationship between the presence of this bacterium and inflammatory changes of antral mucosa in chagasic patients. Seventeen chagasics, with megaesophagus and or megacolon were studied. Fragments from two different regions of antral mucosa were obtained by endoscopy, fixed in 4% neutral formaldehyde and embedded in paraffin. The sections were stained by haematoxylin and eosin for histology analysis, and by carbolfuchsin for H. pylori identification. H. pylori was found in 16 (94.1%) chagasic patients, all of them presenting chronic gastritis. Superficial gastritis was seen in 9 (52.9%) while atrophic gastritis was present in 8 (47.1%) patients. H. pylori was present on gastric mucosa of 8 (100%) patients with atrophic gastritis and of 8 (88.8%) patients with superficial gastritis. We concluded that the microorganism H. pylori should be considered a possible factor connected with the etiopathogenesis of chronic superficial and atrophic gastritis frequently observed in patients with the digestive form of Chagas' disease.

Characterization of the non-apparent clinical form in the initial phase of schistosomiasis mansoni

In this paper the history of 115 recruits that had bathed simultaneously in streams contaminated with Schistosoma mansoni, during military maneuvers, is reported. Thirty four of the infected patients presented the initial phase of the infection diagnosed through epidemiologic, clinical and laboratorial parameters. Three out of the 34 patients did not reveal the clinical picture of the infection, thus being considered representatives of the non-apparent form of the disease. Differences between the intensity of blood eosinophilia, the area of immediate cutaneous reaction and the number of Schistosoma eggs eliminated in the stools proved not to be statistically significant (p>0.05) when the non-apparent and acute cases of schistosomiasis were compared. These cases actually may be considered evidences of the non-apparent form hitherto merely taken for granted in the literature.