Chikungunya Disease Outbreak, Reunion Island

摘要

To the Editor: A serious outbreakof chikungunya disease recentlyoccurred on Reunion Island (popula-tion ≈770,000) (1). Between March 1,2005, and April 30, 2006, ≈255,000cases were reported in this French ter-ritory in the Indian Ocean. Most casesoccurred after mid-December 2005,with a maximum of 45,000 cases dur-ing the week of January 29 toFebruary 4, 2006 (2). Surveillancefigures were confirmed by a serosur-vey that found a prevalence of 18% ofrecent infection markers in pregnantwomen in March 2006.Chikungunya is a self-limitingfebrile viral disease characterized byarthralgia or arthritis. Symptoms maylast for several months, but recoverywas, until now, considered universal(3). However, in January 2006, thehealth authorities on this island start-ed receiving death certificates men-tioning chikungunya as a cause ofdeath, either direct or indirect. By theend of April, 213 death certificateswith this finding had been received.To assess the affect of chikungunyadisease, we compared the crude deathrate (CDR) observed during the out-break period with an expected deathrate computed from the 2002–2004historical data