Invasive pneumococcal disease (IPD) is an important cause of morbidity and mortality among young children and elderly adults in Indiana. The emergence of drug-resistant Streptococcus pneumoniae infections has created renewed urgency to improve vaccination rates among these populations. Though vaccines against particularly virulent and prevalent strains and antimicrobial therapy are available, Indiana still experiences several hundred cases annually among all ages.
IPD surveillance data for confirmed cases with available antimicrobial susceptibility information was gathered from the Indiana National Electronic Disease Surveillance System (INEDSS) from January 1, 2010 to December 31, 2013. Susceptibility information was gathered from provider interviews or electronically reported laboratory data collected during case investigations. Investigations included demographic information, vaccination information, travel/residential history, and other risk factors. Culture isolates from IPD cases in children five and under were sent to the ISDH Laboratory for serotyping whenever possible.
Among cases of IPD (n=3077), 9.7% were in children five and under and 55.2% were in adults over 65 years old. Organisms were most commonly resistant to azithromycin, erythromycin, and trimethoprim/sulfamethoxazole (TMP-SMX). Prevalence of azithromycin and erythromycin resistance increased from 29.4% and 30.4% to 35.8% and 35.7% respectively. Prevalence of penicillin resistance, a focus of recent antimicrobial stewardship efforts, dropped from 17.5% in 2010 to 12.2% in 2013. A mean of 38.0% of cases (n=163) in children five and under had a strain of Streptococcus pneumoniae that was resistant to at least one antibiotic. 40.3% of these cases had a serotype included in the PCV13 pneumococcal vaccine routinely given to children.
It is important to continue to monitor and assess antimicrobial resistance trends in IPD in Indiana to ensure continued effectiveness of treatment and potential targets for antimicrobial stewardship regarding IPD. Understanding trends in antimicrobial resistance and epidemiology of IPD is important to informing preventative action, treatment and vaccine research.
P. Pontones, None