Clindamycin and Intravenous Immunoglobulin for Invasive Group A Streptococcal Infection: Is the Jury Still Out?

Neil M. Ampel, MD

In a prospective, enhanced-surveillance study, the use of clindamycin with or without IVIG in patients with severe disease was associated with a nonsignificant mortality reduction.

In the management of invasive group A streptococcal (iGAS) infection, outstanding issues are whether adding clindamycin improves outcomes over β-lactam antibiotic alone, whether intravenous immunoglobulin (IVIG) further improves outcomes, and whether antibiotic prophylaxis for close contacts might be beneficial. Because iGAS is rare, a controlled trial examining these issues is unlikely to be achieved. Instead, investigators performed an active, prospective, enhanced-surveillance study in the state of Victoria, Australia, between March 1, 2002, and August 31, 2004, and found 333 patients whose condition met a case definition of iGAS, of whom 84 had severe disease. The authors also retrospectively collected data on household contacts for iGAS cases.

Multivariate logistic regression, adjusted for age and the presence of streptococcal toxic shock syndrome, was suggestive of a reduced mortality rate in those with severe iGAS who received clindamycin (odds ratio, 0.31; 95% confidence interval, 0.09–1.12). Similarly, combining IVIG with clindamycin showed a nonsignificant trend toward lower mortality in the severe-iGAS group (OR, 0.12; 95% CI, 0.01–1.29). There were 3 confirmed secondary cases of iGAS among household contacts within 30 days after the index case, yielding an attack rate of 5468 secondary cases per 100,000 person-years. The authors calculated that 4 cases would be prevented by offering antibiotics to approximately 912 close contacts each year.

Citation(s):

Carapetis JR et al. Effectiveness of clindamycin and intravenous immunoglobulin, and risk of disease in contacts, in invasive group A streptococcal infections. Clin Infect Dis 2014 Aug 1; 59:358.