A Mixed Outbreak of Epidemic Typhus Fever and Trench Fever in a Youth Rehabilitation Center: Risk Factors for Illness from a Case-Control Study, Rwanda, 2012

Abstract In August 2012, laboratory tests confirmed a mixed outbreak of epidemic typhus fever and trench fever in a male youth rehabilitation center in western Rwanda. Seventy-six suspected cases and 118 controls were enrolled into an unmatched case-control study to identify risk factors for symptomatic illness during the outbreak. A suspected case was fever or history of fever, from April 2012, in a resident of the rehabilitation center. In total, 199 suspected cases from a population of 1,910 male youth (attack rate = 10.4%) with seven deaths (case fatality rate = 3.5%) were reported. After multivariate analysis, history of seeing lice in clothing (adjusted odds ratio [aOR] = 2.6, 95% confidence interval [CI] = 1.1–5.8), delayed (≥ 2 days) washing of clothing (aOR = 4.0, 95% CI = 1.6–9.6), and delayed (≥ 1 month) washing of beddings (aOR = 4.6, 95% CI = 2.0–11) were associated with illness, whereas having stayed in the rehabilitation camp for ≥ 6 months was protective (aOR = 0.20, 95% CI = 0.10–0.40). Stronger surveillance and improvements in hygiene could prevent future outbreaks.