Regina de Fatima dos Santos Braz

Association between the Tumor Necrosis Factor Locus and the Clinical Outcome of Leishmania chagasi Infection

ABSTRACT A periurban outbreak of visceral leishmaniasis (VL) caused by the protozoan Leishmania chagasi is ongoing outside Natal, northeast Brazil. Manifestations range from asymptomatic infection to disseminated visceral disease. Literature reports suggest that both genetic and environmental factors influence the outcome of infection. Due to the association of the tumor necrosis factor (TNF) locus with other infectious diseases, we examined whether polymorphic alleles at this locus are associated with the outcome of L. chagasi infection. Neighborhoods with ongoing transmission were identified through patients admitted to local hospitals. Altogether, 1,024 individuals from 183 families were classified with the following disease phenotypes: (i) symptomatic VL, (ii) asymptomatic infection (positive delayed-type hypersensitivity [DTH+]), or (iii) no evidence of infection (DTH−). Genotypes were determined at a microsatellite marker (MSM) upstream of the TNFB gene encoding TNF-β and at a restriction fragment length polymorphism (RFLP) at position −307 in the promoter of the TNFA gene encoding TNF-α. Analyses showed that the distribution of TNFA RFLP alleles (TNF1 and TNF2) and the TNF MSM alleles (TNFa1 to TNFa15) differed between individuals with VL and those with DTH+ phenotypes. TNF1 was transmitted more frequently than expected from heterozygous parents to DTH+ offspring (P = 0.0006), and haplotypes containing TNF2 were associated with symptomatic VL (P = 0.0265, transmission disequilibrium test). Resting serum TNF-α levels were higher in TNF1/2 heterozygotes than in TNF1/1 homozygotes (P < 0.05). These data led us to hypothesize that an individuals genotype at the TNF locus may be associated with whether he or she develops asymptomatic or symptomatic disease after L. chagasi infection. The results preliminarily suggest that this may be the case, and follow-up with larger populations is needed for verification.

An Emerging Peri-Urban Pattern of Infection with Leishmania chagasi, the Protozoan Causing Visceral Leishmaniasis in Northeast Brazil

Peri-urban visceral leishmaniasis (VL) caused by Leishmania chagasi is emerging in a new epidemiologic pattern in Brazilian cities. We studied peri-urban VL in endemic neighborhoods surrounding Natal, Brazil, identified through hospitalized individuals with VL. Clinical and environmental information obtained for 1106 members of 216 families living in endemic neighborhoods enabled us to identify 4 groups: VL: individuals with current or prior symptomatic visceral leishmaniasis (n=135); DTH+: individuals with positive delayed-type hypersensitivity response with no history of VL (n=390); Ab+: individuals with negative DTH response and seropositive (n=21); DTH−: individuals with negative DTH and seronegative (n=560). The mean±SD age of VL was 9.3±12.3 y. The gender distribution was nearly equal below age 5, but skewed toward males at higher ages. Acutely infected VL subjects had significantly lower hematocrits, neutrophils, and eosinophils than other categories. AB+ subjects also had lower eosinophil counts than others, a possible immune marker of early infection. VL was not associated with ownership of dogs or other animals, raising the question whether the reservoir differs in peri-urban settings. This new pattern of L. chagasi infection enables us to identify epidemiological and host factors underlying this emerging infectious disease.

Prevalência de marcadores sorológicos do vírus da hepatite B em trabalhadores do serviço hospitalar

OBJETIVO: Determinar a prevalencia de marcadores sorologicos do virus da hepatite B (VHB) e identificar fatores de risco, de transmissao desse virus, no ambiente hospitalar. METODOS: Foram examinados 210 individuos de diversas profissoes que trabalham em hospital universitario. O metodo empregado foi o ELISA e utilizou-se, como grupo-controle, 45 doadores voluntarios de sangue. RESULTADOS: Constatou-se que 20,5% dos profissionais que trabalham no hospital apresentavam positividade para, pelo menos, um dos tres marcadores dos virus pesquisados, contra 6,6% do grupo-controle. Nos trabalhadores do hospital, a prevalencia de cada marcador isoladamente foi: anti-HBc 8,1%, anti-HBs 5,2% e AgHBs 2,9% , sendo que em 4,3% desses individuos foi detectada a presenca simultânea dos marcadores anti-HBc e anti-HBs. No grupo-controle, foi detectada apenas a presenca dos marcadores anti-HBc e anti-HBs, isoladamente, com prevalencias de 4,4 e 2,2%, respectivamente. Os maiores indices de positividade observados foram: pessoal de laboratorio, 24,0%; pessoal de enfermagem, 23,6%; medicos, 20,8%; e pessoal da limpeza, 18,2%. CONCLUSOES: Os achados indicam que os profissionais da saude estao mais expostos a infeccao pelo VHB, sugerindo que o contato com pacientes e a manipulacao de fluidos corporais sao fatores de risco de transmissao ocupacional desse virus, recomendando-se a vacinacao desses profissionais contra a hepatite B.OBJECTIVE To verify the prevalence of the anti-HBc, anti-HBs and HBsAg markers of hepatitis B virus, and to identify the risk factors determining occupational infection with this virus among hospital personnel. METHODS Samples of serum from 210 persons both male and female who work in different occupations at a hospital university, were analysed. The technique employed was the immunoenzymatic assay using commercial kits. RESULTS As a control group, samples of serum from 45 volunteer blood donors were utilized. It was verified that 20.5% of the hospital personnel presented a positive reaction to at least one of the markers songht, as against 6.6% of the control group. The prevalence of each marker separately was: anti-HBc 8.1%, anti-HBs 5.2%, and HBsAg 2.9% in the hospital personnel; and 4.4%, 2.2% and 0.0% in the control group. The simultaneous presence of the anti-HBc and anti-HBs markers was detected in 4.3% of the workers. In the control group, the presence of the anti-HBc and anti-HBs markers was detected, isolately, with respective prevalences of 4.4% and 2.2%. Those who presented the highest rates of positivite reaction were: laboratory technicians 24.0%, nurses 23.6%, physicians 20.8%, and cleaning personnel 18.2%. CONCLUSIONS The findings suggest that direct contact with patients and handling of blood and other body fluids are risk factors related to occupational infection with HBV. Therefore, it is recommended that hospital personnel be vaccinated against hepatitis B.

Kodamaea (Pichia) ohmeri fungemia in a pediatric patient admitted in a public hospital

Kodamaea (Pichia) ohmeri is a yeast species that has not been reported to be a frequent cause of human infections. The current report describes a case of fungemia caused by K. ohmeri in a 3-year-old female patient hospitalized in the public hospital Maria Alice Fernandes, Natal, RN, Brazil. The patient had previously received antimicrobial therapy due to a peritoneal infection and nosocomial pneumonia, and had a central venous catheter implanted. Kodamaea ohmeri was isolated from blood and the tip of the catheter, 48 h after its implantation. The yeast was identified by standard microbiological methods and sequence analysis of the D1/D2 domains and the ITS 1 + 2 spacer regions of the ribosomal DNA. On CHROMagar Candida medium, the isolate showed a color change from pink to blue. The yeast was susceptible to amphotericin B, and liposomal AmB was used successfully to clear the infection.

Genetic Admixture in Brazilians Exposed to Infection with Leishmania chagasi

Visceral leishmaniasis (VL) in northeast Brazil is a disease caused by infection with the protozoan Leishmania chagasi. Infection leads to variable clinical outcomes ranging from asymptomatic infection to potentially fatal disease. Prior studies suggest the genetic background of the host contributes to the development of different outcomes after infection, although it is not known if ancestral background itself influences outcomes. VL is endemic in peri‐urban areas around the city of Natal in northeast Brazil. The population of northeast Brazil is a mixture of distinct racial and ethnic groups. We hypothesized that some sub‐populations may be more susceptible than others to develop different clinical outcomes after L. chagasi infection. Using microsatellite markers, we examined whether admixture of the population as a whole, or markers likely inherited from a distinct ethnic background, differed between individuals with VL, individuals with an asymptomatic infection, or individuals with no infection. There was no apparent significant difference in overall population admixture proportions among the three clinical phenotype groups. However, one marker on Chr. 22 displayed evidence of excess ancestry from putative ancestral populations among different clinical phenotypes, suggesting this region may contain genes determining the course of L. chagasi infection.