Malaria imported into Réunion Island: is there a risk of re-emergence of the disease?

Abstract 

After a long period of endemicity until the 1950s, the World Health Organization considered autochthonous malaria eliminated from Réunion in 1979. To prevent secondary transmission and re-emergence of autochthonous malaria, permanent epidemiologic and entomological surveillance and vector control measures are conducted.

The objective of this study is to report sociodemographic characteristics of imported malaria patients and incidence rates from 2003–2008 using mandatory notification with the aim of identifying risk groups and destinations.

During this period, 684 imported malaria cases were reported. Median age of patients was 34.4 years and 22.1% were children ≤ 15 years. Men represented 67.7% of cases and 59.1% of patients reported having taken chemoprophylaxis based on chloroquine alone. Incidence of malaria was considerably different by country destination. For Comoros, incidence was stable and high during the period accounting for 1481 cases per 100000 travels in 2008. The rate was lower for travels to Madagascar, South Africa and Mayotte and decreased over the period to 37, 19 and 3 per 100000 respectively, by 2008.

To avoid re-emergence of malaria on the island and to protect themselves, travelers should reduce their risks of acquisition and importation of parasites by using adequate preventive measures. A special preventive program and social mobilisation should be a priority, essentially for the Comorian community in Réunion.

Keywords: Imported malaria, Surveillance, Incidence, Réunion Island, Comoros, Re-emergence