Negative evaluation of a pathergy test in hepatitis B surface antigen carriers.

The different cutaneous manifestations of hepatitis B virus infection have been described in different studies. We proposed to evaluate the frequency of skin pathergy positivity in hepatitis B surface antigen carriers. The study group consisted of 92 hepatitis B surface antigen carriers and 76 healthy individuals as a control group. The pathergy test was applied intradermally to both forearms of the patients and the control subjects. The results of the pathergy test were evaluated. Papule or pustule formation was noted as positive. Four and one of the 92 hepatitis patients and 76 control subjects, respectively, were positive for the pathergy reaction. Evidently, this pathergy test that shows non-specific skin hyper-reactivity cannot be used as a clinical marker to indicate hepatitis B surface antigen carriers. The test cannot be used to predict the cutaneous manifestations of hepatitis B infection either.

Assessment of the antibody response in 110 healthy individuals who have been subject to Vi capsular polysaccharide vaccine.

Typhoid fever is a disease predominant in underdeveloped and developing countries. Typhoid fever is more prevalent, in fact endemic, in countries where fecal contamination of water and food sources are very common. The majority of the reported cases are in the adult age group. There are three different vaccines which can be used to prevent typhoid fever. In this study, we have used the parenteral Vi vaccine which was developed using the polysaccharide Vi antigen that covers the bacterial surface, thus, concealing the O antigen protecting the bacteria against Anti-O antibodies and regarded as virulence factor. A total of 110 individuals whose sera were negative for seroconversion prior to vaccination were included in this study in which we have assessed Anti-Vi antibodies by tube agglutination. Serum and stool samples of 110 individuals were assessed 1 month after the vaccination. A total of 105 (95.5%) of the vaccinated people were considered to have positive (1/40 and higher) response and this result was regarded as prophylactic seroconversion. None of the people in the study group had Salmonella typhi, S. paratyphi A,B,C isolated from their stool cultures.