Antidiphtheria antibody of patients and carriers several years after the illness in Indonesia

Diphtheria is a lethal disease and toxin is the most important instrument of pathogenicity. Anti-diphtheria antibody plays a role in determining someone to be healthy, carriers, or be ill. Diphtheria infection will not provide a sufficient antibody level to the patient few months or years after. This study aimed to determine anti-diphtheria antibody level of individuals several years after someone being patients or carriers. The participants of this cross-sectional study were all diphtheria carriers and patients aged < 18 years in East Java Province Indonesia from the period of 2011-2015. The record was obtained from East Java Provincial Health Office. Subjects were visited, interviewed, and underwent physical examinations. Blood samples were obtained and the anti-diphtheria antibody level was determined using the Vero cell method. The result was then modified using WHO criteria. Data analysis used Mann-Whitney U, Kruskal-Wallis, and Chi-Square tests as appropriate with p < 0.05 and 95% confidence interval considered as significant. Among 25 carriers and 88 patients from 21 districts in the study, mostly above five-year-olds, only 11% carriers and 6% patients received three times immunization after the period of illness, indicating that the follow up by health care officers was not satisfactory. The antibody levels of the patients were significantly different from the carriers along with a prevalence ratio of 1.26 if the antibody was at a susceptible level. There were 8% carriers and 20% patients in the susceptible group. In conclusion, six months to 3.5 years after having the illness, diphtheria patients remained to have lower anti-diphtheria antibody levels as compared to the carriers.