BackgroundIndia contributes to 80% of diphtheria cases. Many diphtheria outbreaks were reported from Bijapur district of Karnataka state, India. Analysis of burden and drug sensitivity pattern might help to identify risk groups and to provide guidelines for treatment of diphtheria cases. Our objectives were to describe epidemiology and drug susceptibility of diphtheria cases in Bijapur district.MethodsWe did cross-sectional study between 2012 and 2015. We defined a probable case as inflammation of upper respiratory tract with adherent membranes. We defined a confirmed case as a probable case that was laboratory confirmed by throat culture. We collected line list of probable and confirmed diphtheria cases, population details in Bijapur district and antibiotic sensitivity of culture reports. We calculated attack rates and case fatality rate by taluks of Bijapur district. We calculated proportion of antibiotic resistance among lab confirmed cases.ResultsThere were 229 probable cases and 26 confirmed cases of diphtheria. Attack rate was 110/million and case fatality rate was 2% (5/255). Median age of males was 5 years (range: 3 months to 18 years) and females was 6 years (range: 1 year to 18 years). Highest attack rate (290/million) was in Bagewadi taluk, followed by Sindagi taluk (130/ million). Attack rate in Bijapur, Indi and Muddebihal were 80, 80and 70 per million respectively. Incidence of diphtheria cases was 3/million in 2012, 15/million in 2013, 80/million in 2014 and 14/million in 2015. Penicillin resistance was found among 92% (24/26) of cases, cotrimaxozole resistance among 27% cases (7/26) and ampicillin resistance among 15% cases (4/26)}. Multidrug resistance for penicillin and cotrimoxazole was found among 23% (6/26) of cases. Multidrug resistance to penicillin and ampicillin was found among 15% (4/26) of cases). All cases were sensitive to azithromycin, erythromycin, doxycycline, clindamycin, ciprofloxacin, cefotaxime, gentamycin and tetracycline.ConclusionDiphtheria incidence increased between 2012 and 2014. Incidence reduced in 2015. Penicillin resistance was common. We recommend sensitising health workers about penicillin resistance and educating them not to use penicillin. We recommend estimating vaccine coverage and vaccine effectiveness among children.Disclosures All authors: No reported disclosures.