Trend, morbidity profile and immunization status of diphtheria admitted cases: A 5-years review from a sentinel centre in Kolkata.

Despite strengthening of the universal immunization program, diphtheria remains endemic in India. Diphtheria is under surveillance for vaccine-preventable diseases of the World Health Organization and also in India. The present record-based retrospective study was conducted on 241 confirmed diphtheria patients admitted in an infectious disease hospital of Kolkata over 5 years (2015-2019) with the objectives of assessing the admission trend, immunization status, and outcome of patients. Among the patients, majority (57.3%) were female; 50.6% were ≥15 years; 49.0% resided in rural areas. Five-year admission rate did not show any declining trend. Major number of cases occurred in 2016; another peak observed in 2019. Only 27.4% fully immunized rest either partiality immunized (44.4%) or nonimmunized (28.2%). Overall, 54% of the patients developed any complications, and case fatality was 9.5%. Gradual age shift toward adults reiterated the widespread use of adult immunization with Td vaccines. Early reporting to the hospital is necessary to reduce complications and case fatality.