Detection of hepatitis A antibodies by ELISA using saliva as clinical samples.

The possibility of detecting acute infection and immunity using body fluids that are easier to collect than blood, mainly in children, would facilitate the investigation and follow-up of outbreaks of hepatitis A (HAV). Our study was carried out to evaluate the detection of anti-HAV IgM, IgA and total antibodies in saliva using serum samples as reference. Forty three paired serum and saliva samples were analyzed. From this total, 24 samples were obtained from children and 1 from one adult during the course of acute hepatitis A; an additional 18 samples were obtained from health professionals from Adolfo Lutz Institute. The sensitivity to detect anti-HAV IgM was 100% (95%CI: 79.1 to 100.0%), employing saliva as clinical samples. In detecting anti-HAV IgA, the sensitivity was 80. 8% (95%CI: 60.0 to 92.7%) and for the total antibodies was 82.1% (95%CI: 62.4 to 93.2%). The specificity was 100% for each. The rate of agreement was high comparing the results of serum and saliva samples for detecting HAV antibodies. We conclude that saliva is an acceptable alternative specimen for diagnosing acute hepatitis A infection, and for screening individuals to receive hepatitis A vaccine or immunoglobulin.

Duality of patterns in hepatitis A epidemiology: a study involving two socioeconomically distinct populations in Campinas, São Paulo State, Brazil.

To evaluate the prevalence of antibodies against hepatitis A in two socioeconomically distinct populations, 101 and 82 serum samples from high and low socioeconomic groups, respectively, were analysed for the presence of IgG anti-HAV using a commercial ELISA. The prevalence in low socioeconomic level subjects was 95.0%, whereas in high socioeconomic subjects was only 19.6% (p < 0.001). These data show a duality in Brazil: anti-HAV prevalence in low socioeconomic subjects is similar to that of developing countries, while in high socioeconomic subjects, a pattern typical of developed countries is found. The control of this infection in our country is primarily related to the improvement of sanitation, but especially for high socioeconomic level populations, the use of vaccination against hepatitis A is strongly advisable to avoid the occasional appearance of this disease in adults.

[The incidence of hepatitis B markers in pregnant women at their first consultation in metropolitan-area health centers, São Paulo, Brazil]. / Frequência de marcadores de hepatite B em gestantes de primeira consulta em centros de saúde de área metropolitana, São Paulo, Brazil.

Hepatitis B is a severe disease when acquired during the neonatal period. The identification of the infected pregnant women allows prevention of newborn infection by active and passive immunization soon after birth. We studied pregnant women in their first visit to eight different primary medical centers in Butantan, a subdistrict of S. Paulo city. 477 samples were tested for anti-HBc. From 44 (9.2%) anti-HBc positive samples, 2 (0.4%) were HBsAg positive and 37 (7.7%) were anti-HBs positive. A risk factor for hepatitis B could only be detected in 8 (18.9%) of the 44 anti-HBc positive samples.

Active immunization against hepatitis B virus (HBV) with low-doses of plasma-derived vaccine by intradermal route.

Schedule for vaccination against HBV infection has usually been based on three separate injections of 20 mcg of the vaccine by intramuscular route. One of the main shortcomings to its use in large scale programs has been its high cost. Ninety out of 300 health workers were submitted to three injections of 2 mcg of plasma-derived vaccine (PDV) by intradermal (ID) route on days 0, 30, and 180. Anti-HBs was detected in 74 (82.2%) after the second dose and in 80 (88.9%) after the third dose, a non-significant difference. However, levels above 10 times the cut-off were observed in 29 (32.2%) and 77 (85.5%), respectively (p less than 0.001). The results showed that a low-dose schedule is effective when used in health workers and should be tried with other risk groups.