HTLV-1 and -2 in a first-time blood donor population in Northeastern Brazil: Prevalence, molecular characterization, and evidence of intrafamilial transmission.

Independent epidemiology for respective human T-cell lymphotropic virus (HTLV) types 1 and 2 is little known in blood donors in Brazil, where screening for HTLV-1/2 is mandatory at blood banks, but no testing to confirm/differentiate these viruses. Therefore, this study aims to assess the prevalence of HTLV-1 and -2 in a first-time blood donor population in Northeastern Brazil and to carry out molecular characterization of respective isolates. A cross-sectional study was conducted at the State Blood Bank in Piauí. Samples were screened for anti-HTLV-1/2 by enzyme immunoassay, and reactive samples were confirmed using a line immunoassay and polymerase chain reaction (PCR). Of 37 306 blood donors, 47 were anti-HTLV-1/2 reactive by enzyme immunoassay. After confirmed by line immunoassay, 22 were positive for HTLV-1 (0.59 per 1000; 95% CI: 0.38-0.87), 14 were positive for HTLV-2 (0.37 per 1000; 95% CI: 0.21-0.61), 1 was indeterminate, and the remaining donors were negative. The HTLV-1 infection was also confirmed by PCR in all anti-HTLV-1-positive samples, and sequencing classified these isolates as belonging to the Transcontinental (A) subgroup of the Cosmopolitan (1a) subtype. Of 14 anti-HTLV-2-positive samples, 11 were also PCR positive, which belonged to subtype a (HTLV-2a/c). In addition, 38 family members of 5 HTLV-1- and 3 HTLV-2-infected donors were analyzed. Familial transmission of HTLV-1 and -2 was evidenced in 3 families. In conclusion, in Northeastern Brazil, where HTLV-1 and -2 are endemic, counseling blood donor candidates and their families might play a key role in limiting the spread of these viruses.

Safety and immunogenicity of hepatitis B vaccine administered into ventrogluteal vs. anterolateral thigh sites in infants: a randomised controlled trial.

BACKGROUND: Lowered immune response to hepatitis B vaccines has been found in individuals vaccinated into dorsogluteal site compared to vastus lateralis thigh muscle. OBJECTIVE: The aim of this study was to compare the immunogenicity and reactogenicity of a hepatitis B vaccine in infants vaccinated into ventrogluteal or anterolateral thigh sites. DESIGN: Randomised controlled trial. SETTING AND PARTICIPANTS: The recruitment of study participants was carried out from February to November 2007 in the five maternity hospitals located in the eastern region of Goiânia City, Central Brazil. Newborns up to 12h old weighing at least 2.5 kg were enrolled in the study. METHODS: A total of 580 newborns were randomised to receive three hepatitis B vaccine doses into ventrogluteal (n=286) or anterolateral thigh (n=294) sites. Of them, 474 (81.7%) completed the study: 224 from the ventrogluteal group (intervention group) and 250 from the anterolateral thigh group (control group). Fever and local adverse events were evaluated 48 h after each vaccine dose. Blood samples (3 mL) were collected between 45 and 60 days after the third vaccine dose, and anti-HBs antibody titres were determined by automatic analysis using the Microparticle Immunoenzymatic Test (AxSYM Ausab, Abbott, Germany). RESULTS: The groups did not differ by gender, weight, length of time between vaccine doses, or maternal characteristics. The proportion of infants who developed protective anti-HB titres after full vaccination into the ventrogluteal site was 97.8% (95% confidence interval [CI]: 94.8-99.3; geometric mean titre: 427.5 mIU/mL; 95% CI: 344.9-530.0), similar to that of infants vaccinated into the anterolateral thigh site (97.6%; 95% CI: 94.8-99.1; geometric mean titre: 572.0 mIU/mL; 95% CI: 471.1-694.6). No complication was found after 1503 vaccine doses, but a lower proportion of fever and local adverse events was found among the intervention group (17.9%) vs. the control group (23.7%) (p<0.01). CONCLUSION: Our results suggest that the ventrogluteal region is a suitable site for intramuscular injection in infants, particularly for the hepatitis B vaccine.