Persistence of anti–chikungunya virus–specific antibodies in a cohort of patients followed from the acute phase of infection after the 2007 outbreak in Italy

Chikungunya is a mosquito-borne infection of humans, and its diffusion has increased worldwide. In 2007 an outbreak occurred in Italy. In this study, the antibody response of 133 patients followed up starting from the acute phase of infection was investigated. Antibody titres were periodically scored up to 1 year since the infection: 82.7% of the IgM antibody disappeared within 12 months, and the IgG response lasted longer than 12 months. Nevertheless, the IgG mean titre was lower in 95.5% of patients at the end of follow-up, thus suggesting a decrease within a relatively short period.