Interferon-gamma release assay performance in northeastern Brazil: influence of the IFNG+874 A>T polymorphism

ABSTRACT Introduction Latent tuberculosis infection diagnosis based on the release of interferon-gamma in cultures of peripheral blood cells stimulated with Mycobacterium tuberculosis antigens has replaced the tuberculin skin test in many countries with low tuberculosis prevalence. The IFN-γ production can be influenced by genetic polymorphisms, of which the IFNG + 874 (rs62559044) locus is the most studied. We investigated the possible influence of the IFNG + 874 A/T polymorphism on interferon-gamma test performance. Methods Patients diagnosed with pulmonary tuberculosis (75), volunteers with positive tuberculin skin test (70) and healthy volunteers with negative tuberculin skin test and no history of contact with tuberculosis (57) were evaluated regarding the IFNG + 874 genotype and the IFN-γ levels in whole blood cultures performed using an interferon-gamma commercial kit (QuantiFERON-TB® Gold In-Tube). Results IFN-γ production was not influenced by the IFNG + 874 genotype, regardless of antigen or mitogen-based stimulation, which suggests that other genes may influence IFN-γ production in response to mycobacteria. The IFNG + 874 polymorphism was found to exert no influence over QFT-IT test sensitivity in our study. Conclusions The IFNG + 874 polymorphism was not shown to influence QuantiFERON-TB® Gold In-Tube test performance in an admixed population from northeastern Brazil.

Characteristics of co-infections by HCV and HBV among Brazilian patients infected by HIV-1 and/or HTLV-1

BACKGROUND: The human retroviruses HIV-1 and HTLV-1 share the routes of infection with hepatitis viruses B and C. Co-infection by these agents are a common event, but we have scarce knowledge on co-infection by two or more of these agents. OBJECTIVE: To evaluate the characteristics and risk factors for co-infections by HBV and HCV in patients infected by HIV-1 or/and HTLV-1, in Salvador, Brazil. METHODS: In a case-control study we evaluated patients followed in the AIDS and HTLV clinics of Federal University of Bahia Hospital. Clinical and epidemiological characteristics were reviewed, and patients were tested for the presence of serological markers of HBV and HCV infections. HCV-infected patients were tested by PCR to evaluate the presence of viremia. RESULTS: A total of 200 HIV-1, 213 HTLV-1-infected, and 38 HIV-HTLV-co-infected individuals were included. HIV-infected patients were more likely to have had more sexual partners in the lifetime than other patients' groups. HIV-HTLV-co-infected subjects were predominantly male. Patients infected by HTLV or co-infected had a significantly higher frequency of previous syphilis or gonorrhea, while HIV infection was mainly associated with HPV infection. Co-infection was significantly associated to intravenous drug use (IVDU). HBV and/or HCV markers were more frequently found among co-infected patients. HBV markers were more frequently detected among HIV-infected patients, while HCV was clearly associated with IVDU across all groups. AgHBs was strongly associated with co-infection by HIV-HTLV (OR = 22.03, 95% CI: 2.69-469.7), as well as confirmed HCV infection (p = 0.001). Concomitant HCV and HBV infection was also associated with retroviral co-infection. Patients infected by HTLV-1 had a lower chance of detectable HCV viremia (OR = 0.04, 95% CI: 0.002-0.85). CONCLUSIONS: Infection by HCV and/or HBV is frequent among patients presenting retroviral infection, but risk factors and prevalence for each infection are distinct for each agent. Retroviral co-infection increases the risk of a positive AgHBs, but HTLV-1 infection seems to increase the likelihood of HCV spontaneous clearance.

Ancestry informative markers and complete blood count parameters in Brazilian blood donors / Marcadores informativos de ancestralidade e parâmetros no hemograma de doadores de sangue brasileiros

A complete blood count is very useful in clinical diagnoses when reference ranges are well established for the population. Complete blood counts and allele frequencies of Ancestry Informative Markers (AIMs) were analyzed in Brazilians with the aim of characterizing the hematological values of an admixed population. Positive associations were observed between gender and neutrophils, monocytes, eosinophils, erythrocytes, hemoglobin, hematocrit, MCV, MCHC and platelet counts. No significant differences were found for age, alcohol consumption, educational status, ethnicity, smoking in respect to the complete blood count values. In general, men had higher red blood cell values, while women had higher values for white blood cells and platelets. The study of the population was highly heterogeneous with mean proportions (± SE) of African, European and Amerindian ancestry being 49.0 ± 3.0 percent, 44.0 ± 9.0 percent and 7.0 ± 9.0 percent, respectively. Amerindian ancestry showed limited contribution to the makeup of the population, but estimated ancestral proportions were statistically significant (r = 0.9838; P<0.001). These hematologic values are similar to Afro-Americans, another admixed population.

O hemograma é muito útil no diagnóstico quando o intervalo de referência é adequadamente estabelecido para população. Com o objetivo de verificar os valores hematológicos em população heterogênea foi analisado o hemograma e frequências alélica de marcadores informativos de ancestralidade de brasileiros. Foi observada associação positiva entre sexo e os valores de neutrófilos, monócitos, eosinófilos, eritrócitos, hemoglobina, hematócrito, MCV, MCHC e plaquetas (IC 95 por cento; P<0,05). E não houve diferenças entre idade, consumo de álcool, nível educacional, etnia, tabagismo e os valores do hemograma (IC 95 por cento; P>0,05). Os homens apresentaram valores maiores no eritrograma, enquanto no leucograma e plaquetograma foram as mulheres. Foi observado também que a população é altamente heterogênea e as médias proporcionais (±DP) de ancestralidade Africana, Europeia e Ameríndia estimada foram: 49,0 ± 3,0 por cento, 44,0 ± 9,0 por cento e 7,0 ± 9,0 por cento, respectivamente. A contribuição ancestral ameríndia se demonstrou pequena, mas a estimativa de proporções ancestrais foi estatisticamente significante (r = 0,9838; P<0,001). Os valores hematológicos aqui descritos são parecidos com os descritos em negros americanos, outra população heterogênea.

Evaluation of blood stream infections by Candida in three tertiary hospitals in Salvador, Brazil: a case-control study

Invasive infections caused by Candida spp. are an important problem in immunocompromised patients. There is scarce data on the epidemiology of blood stream candidiasis in Salvador, Brazil. This study evaluates the risk factors associated with candidemia, among patients admitted to three tertiary, private hospitals, in Salvador, Brazil. We conducted a case-control, retrospective study to compare patients with diagnosis of candidemia in three different tertiary hospitals in Salvador, Brazil. Patients were matched for nosocomial, acquired infections, according to the causal agent: cases were defined by positive blood cultures for Candida species. Controls were those patients who had a diagnosis of systemic bacterial infection, with a positive blood culture to any bacteria, within the same time period (± 30 days) of case identification. The groups were compared for the main known risk factors for candidemia and for mortality rates. A hundred thirty-eight patients were identified. Among the 69 cases, only 14 were diagnosed as infected by Candida albicans. Candida species were defined in only eight cultures: C. tropicalis (4 cases), C. glabrata, C. parapsilosis, C. guillermondi, C. formata (1 case each). The main risk factors, identified in a univariate analysis, were: presence of a central venous catheter (CVC), use of parenteral nutrition support (PNS), previous exposure to antibiotics, and chronic renal failure (CRF). No association was detected with surgical procedures, diabetes mellitus, neutropenia or malignancies. Patients were more likely to die during the hospitalization period, but the rates of death caused by the infections were similar for cases and controls. The length of hospitalization was similar for both groups, as well as the time for a positive blood culture. Blood stream infection by Candida spp. is associated with CVC, PNS, previous use of antibiotics, and CRF. The higher mortality rate for cases probably better reflects the severity of the underlying diseases, than as a direct consequence of Candidemia.

Risk of tuberculosis among household contacts in Salvador, Bahia

Tuberculosis is one of the most important infectious diseases in the world. Only 68 percent of the estimated new tuberculosis (TB) cases in Brazil are diagnosed. Our aim was to determine the risk of infection among household contacts. Study design. Cohort of tuberculin-negative household contacts followed for 12 Months. Methods. Household contacts of randomly selected index acid-fast bacilli (AFB)-positive TB cases were evaluated through clinical examination, thorax X-ray, tuberculin, AFB smear and culture. Contacts with a negative response to the tuberculin test (less than 10 mm diameter) were retested after 90 days. Tuberculin reversal (used as a parameter of infection risk) was defined as an increase of at least 10 mm from the last measurement. Results. 269 household contacts were followed. The prevalence of disease in this population was 3.7 percent. The prevalence of infection after the 12-month follow-up period was 63.9 percent. The risk of infection was 31.1 percent within 120 ± 48 days. Conclusion. Household contacts of AFB positive tuberculosis patients have a very high prevalence and risk of tuberculosis infection. TB preventive or therapeutic measures directed towards this group should be implemented in Brazil.

Aspectos psicossociais e estigmatizantes da leishmaniose cutâneo-mucosa / Psychosocial aspects and stigmatizing of mucocutaneous leishmaniasis

Os autores selecionaram 15 pacientes portadores de leishmaniose cutâneo-mucosa (LCM) forma grave, onde buscaram, através de entrevista psicológica, conhecer aspectos da vida de cada um, antes de contrair a doença, no decorrer e após o tratamento. Concomitantemente, realizaram 25 entrevistas com a comunidade onde residem os pacientes, com a intençäo de avaliar as reaçöes da mesma ao doente com leishmaniose. Constataram que entre os pacientes entrevistados: 14(93,3%) referiram algum tipo de modificaçäo no decorrer da doença; 11(73,3%) perceberam-se marginalizados; 9(60%) sentiram-se afastados do convívio da sociedade; 10(66,6%) tiveram dificuldade de retornar ao trabalho. Na comunidade, 11(44%) associam o portador da LCM a indivíduos que apresentam deformaçöes no corpo, 8(32%) têm receio de contrair a doença pelo caráter destrutivo das lesöes, 24(96%) referiram que os pacientes têm problemas de relacionamento social

El cultivo "in vitro" como instrumento práctico para el diagnóstico y aislamiento primario de Leishmania braziliensis braziliensis: 2. Estudios en pacientes de áreas endémicas / In vitro cultivation as a practical tool for the diagnosis and primary isolation of Leishmania braziliensis braziliensis: 2. Studies in patients of endemic areas

El cultivo "in vitro" de Leishmania braziliensis braziliensis constituye un método útil en el trabajo de campo, para el aislamiento primario de ésta subespécie de Leishmania. Cultivos en dos medios difásicos de agar sangre (DAB y EVANS) y dos medios líquidos (SCHNEIDER'S y AR-103) realizados en pacientes con lesiones cutáneas de Leishmaniasis Tegumentaria Americana (LTA) demostraron: 1) Similar sensibilidad de los medios DAB y SCHNEIDER'S cuando utilizamos el procedimiento de aspiración de las muestas con aguja. 2) Rendimiento sensible y reproducible, con el medio DAB, cuando comparado, en repetidas ocasiones, con el medio EVANS. 3) Incremento significativo en el aislamiento primario de Leishmania braziliensis braziliensis mediante la ejecución, en la misma lesión de cada paciente, de tres aspiraciones consecutivas en sitios diferentes de la úlcera activa (50% de positividad, con el medio DAB)

El método de cultivo "in vitro" como instrumento práctico en el diagnóstico y el aislamiento primário de Leishmania braziliensis braziliensis: I. Observaciones de laboratório / The in vitro culture method as practical instrument in the diagnosis and primary isolation of Leishmania braziliensis braziliensis: I. Laboratory observations

Comparamos diferentes medios artificiales y procedimientos de cultivo in vitro de Leishmania braziliensis braziliensis (Lbb) aislada de lesiones de hamsteres experimentalmente infectados. Observamos que la aspiración de material de la lesión, usando jeringa de 5 ml y aguja 22g (25 x 8mm), mostró resultados satisfactorios siendo un procedimiento conveniente de colecta. El medio de Agar Sangre Difco (DAB) es un medio eficiente para el aislamiento de Lbb. El medio de Evans demostró similares resultados al DAB, mientras que el medio líquido de Schneider y el químicamente definido AR-103 fueron nítidamente inferiores. En la propagación in vitro de Lbb, el medio de Schneider permitió un buen crecimiento del flagelado, alcanzando densidades de 0,21 - 2,57 x 10**8 promastigotes por ml ya, en el 5§ día de cultivo. La adición de 5-fluorocytosine a los tubos de cultivo (150micron grama/ml) para evitar la contaminación por hongos, no inhibió el crecimiento de Lbb