Historical Malaria Epidemics on Previously Non-Endemic Indo-Pacific Islands

Islands without prior malaria have on occasion had severe epidemics after its initial introduction, the most infamous example being the Indian Ocean island of Mauritius in 1867. The historical record was examined to see if additional examples of malaria epidemics on Indo-Pacific islands, which were originally non-malarious had been documented. The late nineteenth century depopulation of Polynesian outliers such as Ontong Java has largely been blamed on malaria. Similar but less well-documented instances exist with both the Western Islands, Papua New Guinea, and Rennell in the Solomon Islands. Specific instances of malaria introduction to Grand Comoros and Aldabra Island in the Seychelles occurred by the early twentieth century. In some cases, the epidemics were caused by changes in anopheline vectors while in others new human populations carrying parasites were the important ecological change. It is, however, remarkable how rarely major malaria epidemics have occurred on Indo-Pacific islands.