Prevalence of HTLV-1/2 in Pregnant Women Living in the Metropolitan Area of Rio de Janeiro

Abstract

HTLV-1/2 infection can cause severe and disabling diseases in children and adults. The aim of the study was to estimate the prevalence of HTLV-1/2 infection in pregnant women living in the metropolitan area of Rio de Janeiro. 1,204 pregnant women were tested upon hospital admission for delivery in two public hospitals in the cities of Rio de Janeiro and Mesquita, between November, 2012 and April, 2013. The samples were screened by chemiluminescent microparticle immunoassay (CMIA) and reactive ones were confirmed by Western blot (WB). Epi-info software was used for building the database and performing the statistical analysis. Eight patients had confirmed HTLV-1/2 infection (7 HTLV-1, one HTLV-2), equivalent to a prevalence rate of 0.66%. Two further reactive screening tests had negative Western blot results and therefore were considered negative in the statistical analysis. All HTLV-1/2-positive patients were born in Rio de Janeiro, most were non-Caucasian (87.5%), in a stable relationship (62.5%), had at least ten years of formal education (62.5%) and a monthly family income of up to US$600.00 (87.5%). There was only one case of coinfection with syphilis and none with HIV. The mean age of the infected women was 28.4 (SD = 6.3) years and of the seronegative ones was 24.8 (SD = 6.5) (p = 0.10). The median number of pregnancies were 3.0 and 1.0 (p = 0.06) and the median number of sexual partners were 3.5 and 3.0 (p = 0.33) in the seropositive and negative groups, respectively. There were no statistically significant differences between the groups. A significant prevalence of HTLV-1/2 was found in our population. The socio-epidemiological profile of carrier mothers was similar to the controls. Such findings expose the need for a public health policy of routine HTLV-1/2 screening in antenatal care, since counselling and preventive measures are the only strategies currently available to interrupt the chain of transmission and the future development of HTLV-1/2-related diseases. HTLV-1/2 are retroviruses transmitted by blood products, sexual contact and from mother to child, mainly through breastfeeding. The infection has a characteristic geographical distribution with endemic areas often neighbouring very low prevalence areas. Infection is life long and although asymptomatic in most cases, it can cause severe and disabling diseases in children and adults. There is currently no cure, vaccine or effective treatment for HTLV-1/2 infections. Our research is the first to study the prevalence of HTLV-1/2 in pregnant women living in the metropolitan area of Rio de Janeiro, the second largest in Brazil. 1,204 pregnant women were tested upon hospital admission for delivery in two public hospitals in the cities of Rio de Janeiro and Mesquita, between November, 2012 and April, 2013 and a significant prevalence of HTLV-1/2 was found (0.66%). The socio-epidemiological profile of carrier mothers was similar to the controls'. Epidemiological knowledge is fundamental for the elaboration of public health policies such as routine HTLV-1/2 screening in antenatal care, since counselling and preventive measures, mainly avoidance of breastfeeding, are the only strategies currently available to interrupt the chain of transmission and the future development of HTLV-1/2-related diseases.