Clinical, serological and epidemiological features of hepatitis A in León, Nicaragua.

BACKGROUND AND OBJECTIVES: To monitor and document the endemicity and disease burden of acute hepatitis A in the area of an ongoing vaccine effectiveness study in León, Nicaragua. METHODS: At community health centres in León, all children, adolescents and young adults presenting with jaundice and/or other clinical signs of hepatitis were offered free serologic screening (hepatitis A, B and C) and blood tests for liver enzymes and bilirubin. Clinical and socioeconomic data were collected with a structured questionnaire. Diagnosis of acute hepatitis A was confirmed by anti-HAV IgM testing. Using logistic regression we compared the characteristics and living conditions of acute hepatitis A cases with those of non-cases. RESULTS: Of 557 eligible subjects enrolled between May 2006 and March 2010, 315 (56.6%) were diagnosed with hepatitis A, 80.6% of them ≤10 years and five >18 years of age. No severe cases were encountered. Apart from jaundice (95.6%) and other signs of hepatitis A (fever, pale stool, dark urine, nausea, vomiting, anorexia), two thirds of patients had moderately raised liver enzymes. Cases occurred throughout the year, with highest incidences from August to March. Poor sanitary conditions and crowding were the main risk factors. CONCLUSIONS: In the study area, hepatitis A is still highly endemic in young and school age children living in low socioeconomic conditions. There are, however, first indications that the endemicity level is shifting from high to high-intermediate.

In Utero Exposure to Antiretroviral Drugs: Effect on Birth Weight and Growth Among HIV-exposed Uninfected Children in Brazil.

BACKGROUND: There are concerns about the effects of in utero exposure to antiretroviral drugs (ARVs) on the development of HIV-exposed but uninfected (HEU) children. The aim of this study was to evaluate whether in utero exposure to ARVs is associated with lower birth weight/height and reduced growth during the first 2 years of life. METHODS: This cohort study was conducted among HEU infants born between 1996 and 2010 in Tertiary children's hospital in Rio de Janeiro, Brazil. Weight was measured by mechanical scale, and height was measured by measuring board. Z-scores for weight-for-age (WAZ), length-for-age (LAZ) and weight-for-length were calculated. We modeled trajectories by mixed-effects models and adjusted for mother's age, CD4 cell count, viral load, year of birth and family income. RESULTS: A total of 588 HEU infants were included of whom 155 (26%) were not exposed to ARVs, 114 (19%) were exposed early (first trimester) and 319 (54%) later. WAZ were lower among infants exposed early compared with infants exposed later: adjusted differences were -0.52 (95% confidence interval [CI]: -0.99 to -0.04, P = 0.02) at birth and -0.22 (95% CI: -0.47 to 0.04, P = 0.10) during follow-up. LAZ were lower during follow-up: -0.35 (95% CI: -0.63 to -0.08, P = 0.01). There were no differences in weight-for-length scores. Z-scores of infants exposed late during pregnancy were similar to unexposed infants. CONCLUSIONS: In HEU children, early exposure to ARVs was associated with lower WAZ at birth and lower LAZ up to 2 years of life. Growth of HEU children needs to be monitored closely.

Decreasing risk of hepatitis A infection in León, Nicaragua: evidence from cross-sectional and longitudinal seroepidemiology studies.

BACKGROUND AND OBJECTIVES: Nicaragua is highly endemic for hepatitis A. We aimed to provide an estimate of the change in the age-specific risk of hepatitis A virus (HAV) infection based on serological data from cross-sectional and longitudinal samples collected in León, Nicaragua, in 1995/96 (n = 979) and 2003 (n = 494). METHODS: The observed age-specific prevalence of anti-HAV antibodies was correlated to the age-specific risk of infection by calculating the probability of freedom from infection at a specific age. RESULTS: The proportion of seropositive children aged 1.5 to 6 years was 42% in 2003 compared to 67% in 1995/96. Estimated annual risk of infection for a 3-year old child was 30% (95% CI: 27.0%, 33.1%) in 1995 and 15.5% (95% CI: 12.4%, 19.0%) in 2003. There was good agreement between estimates based on cross-sectional and longitudinal data. The age-specific geometric mean of the quantified anti-HAV antibody levels assessed in 2003 was highest at age 4 and decreased steadily up to age 40. CONCLUSIONS: The substantially lower risk of HAV infection in 2003 than in 1995 for young children indicates a beginning transition from high to intermediate endemicity in León, Nicaragua. Consecutive age-stratified serosurveys are useful to assess changes in risk of infection following public health interventions. The decreasing age-specific GMC of anti-HAV antibodies during adulthood in a country with endemic HAV indirectly suggests that ongoing HAV exposure in the community has marginal boosting effect on antibody levels once protective immunity has been established by natural infection.

Selenium for preventing cancer

BACKGROUND: Selenium is a trace element essential to humans. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancers. OBJECTIVE: Two research questions were addressed in this review: What is the evidence for: 1. an aetiological relationship between selenium exposure and cancer risk in women and men?; 2. the efficacy of selenium supplementation for cancer prevention in women and men? SEARCH STRATEGY: We searched electronic databases and bibliographies of reviews and included publications. SELECTION CRITERIA: We included prospective observational studies to answer research question (a) and randomised controlled trials (RCTs) to answer research question (b). DATA COLLECTION AND ANALYSIS: We conducted random effects meta-analyses of epidemiological data when five or more studies were retrieved for a specific outcome. We made a narrative summary of data from RCTs. MAIN RESULTS: We included 49 prospective observational studies and six RCTs. In epidemiologic data, we found a reduced cancer incidence (summary odds ratio, OR, 0.69; 95 percent confidence interval, CI, 0.53 to 0.91) and mortality (OR 0.55, 95 percent CI 0.36 to 0.83) with higher selenium exposure. Cancer risk was more pronouncedly reduced in men (incidence: OR 0.66, 95 percent CI 0.42 to 1.05) than in women (incidence: OR 0.90, 95 percent CI 0.45 to 1.77). These findings have potential limitations due to study design, quality and heterogeneity of the data, which complicated the interpretation of the summary statistics. The RCTs found no protective efficacy of selenium yeast supplementation against non-melanoma skin cancer or L-selenomethionine supplementation against prostate cancer. Study results for the prevention of liver cancer with selenium supplements were inconsistent and studies had an unclear risk of bias. The results of the Nutritional Prevention of Cancer Trial (NPCT) and SELECT raised concerns about possible harmful effects of selenium supplements. AUTHORS' CONCLUSIONS: No reliable conclusions can be drawn regarding a causal relationship between low selenium exposure and an increased risk of cancer. Despite evidence for an inverse association between selenium exposure and the risk of some types of cancer, these results should be interpreted with care due to the potential limiting factors of heterogeneity and influences of unknown biases, confounding and effect modification. The effect of selenium supplementation from RCTs yielded inconsistent results. To date, there is no convincing evidence that selenium supplements can prevent cancer in men, women or children.

Cancer in first degree relatives of Latin American women with cervical cancer. A pilot study.

BACKGROUND: Cervical cancer is the most frequent cancer of women in Latin America, being strongly associated with infection by certain human papillomavirus (HPV) types. Familial cancer clustering can be due to interactions between infectious agents and host genes. MATERIALS AND METHODS: A cancer-related family history of first degree relatives was elicited in 335 women with invasive cervical cancer (probands) and in 335 women without cancer (controls) in Honduras, Peru and Uruguay, and the frequency of reported familial cancers among the relatives was compared between proband and control relatives. RESULTS: The mean age at the time of interview was 49.8 years for the probands and 50.1 years for the controls (NS). 3852 proband relatives had 114 primary cancers of the following major localisations: 22 uterus, 16 lung, 12 stomach and 64 others. 3333 control relatives had 101 primary cancers of the following major localizations: 18 uterus, 13 stomach, 12 breast, 11 intestinal, 10 lung and 37 others. The frequency of all cancer diagnosis among proband relatives was similar to the frequency among control relatives (odds ratio= 1.01; 95% confidence interval: 0.69-1.47). Nine haemolymphatic malignancies were reported among proband relatives versus 2 in control relatives (odds ratio=3.46; 95% confidence interval: 0.74-16.29). CONCLUSION: All cancer combined did not appear to be more frequent in first degree relatives of women with cervical cancer diagnosis, but haemolymphatic malignancies, a minor part of the cancer burden, may be overrepresented in relatives of women with cervical cancer, pointing to a pathogenic role of familial e.g. hereditary, immunosuppression.