Infecção pelo vírus da hepatite A em área indígena da Amazônia oriental brasileira

Abstract

RESUMOA hepatite viral A representa grave problema de saúde pública em todo o mundo, conhecida também como hepatite infecciosa, epidêmica, MS-1 ou hepatite de incubação curta, tem como agente etiológico o vírus da hepatite A (HAV) 5 , da família Picornaviridae, gênero Hepatovirus 10 , com diâmetro de 27-28nm, forma esférica, não envelopado, genoma constituído de RNA de fita simples com cerca de 7.474 nucleotídeos, transmissão através da via fecal-oral por veiculação hídrica e alimentos contaminados, pode ser encontrado nas fezes, três semanas antes a duas semanas depois do início dos sintomas, possui curto tempo de viremia e baixa concentração viral no sangue, à exceção das formas prolongadas, onde pode ser detectado nas fezes por alguns meses após o início do quadro clínico 19 , infectante mesmo após sua permanência por cerca de quatro semanas à temperatura ambiente, pode ser inativado pela fervura de cinco minutos, por solução de formol ≤ a 1: 4.000 e pelo hipoclorito de sódio 1mg/L por trinta minutos 13 16 . Revista da Sociedade Brasileira de Medicina Tropical 37 (Suplemento II), 2004HEPATOLOGIA TROPICAL

Molecular epidemiology of hepatitis A virus in Brazilian Amazon

“…Hepatitis A constitutes an important problem of public health, mainly in the developing countries, due to the poor socioeconomic and hygiene conditions of the populations. Although the prevalence of anti‐HAV antibodies is declining in various South American areas, 1–3 two recent studies performed with Amerindian and riverine communities of the Brazilian Amazon have demonstrated a persistently high (93–98%) endemicity of HAV, 14,15 significantly greater than the mean rate (65%) estimated for Brazil 16,17 . These high anti‐HAV prevalences are correlated with the poor water quality and sanitary conditions present in the Amazon.…”

Prevalence of antibodies against hepatitis A virus among the Kuikuro and Kaiabi Indians of Xingu National Park, Brazil

“…In fact, in high endemicity areas, infection occurs in the five first years of life, with few if any symptoms 1,8,15 . Data is also compatible with the 98% seroprevalence of hepatitis A among 352 Xicrin Indians 15 , among Parakanã and Asurini populations -100% (n = 58) 5 -and with the 96.6% seroprevalence found among the Katukinos of the occidental Amazon region, obtained from 32 individuals 12 .…”

“…It is a disease of universal distribution, with different degrees of endemicity -high, intermediate, low and very low -varying in geographic regions according to socioeconomic, hygiene and health conditions 15,17 . Hepatitis A may be asymptomatic or symptomatic -with or without ictericia.…”

“…These characteristics change where socioeconomic and hygiene conditions improve: endemicity is reduced and the age of infection increases 7,15 . Lifelong immunity follows infection, and IgG antibodies against Hepatitis A Virus are usually present one to four weeks after the clinical symptoms 19 .…”

“…This schedule does not include vaccination against Hepatitis A Virus, partially due to the lack of recent studies 5,12,15 in these populations to evaluate this need and justify the adoption of that measure. Therefore, our aim was to estimate the Hepatitis A seroepidemiology in a West Central bordering Northern region in Brazil, a geographically and culturally well defined Indigenous population territory.…”