Chikungunya is a mosquito-borne virus that causes acute fever and persistent polyarthritis. Recent explosive outbreaks of chikungunya have been reported from many Asian countries and Islands in the Indian Ocean. Many of these outbreaks were caused by strains from the East/Central/Southern African (ECSA) genotype and harboured a mutation (E1:A226V) in the E1 glycoprotein gene that enables CHIKV to replicate and spread more efficiently in Aedes albopictus mosquitoes.

In June 2012 an outbreak of fever and arthritis was detected in Vanimo, Papua New Guinea through a Mobile Phone-based Surveillance system. Subsequent investigations showed that the outbreak was caused by a CHIKV strain from the ECSA genotype. Sequence analysis of the E1 glycoprotein gene revealed that the outbreak strain harboured the E1:A226V mutation. Entomological investigations revealed a high density of Aedes albopictus mosquitoes in the outbreak area. The outbreak in Vanimo resulted in >1,500 suspected cases of chikungunya. In the following months the chikungunya outbreak spread throughout the country. To date, chikungunya outbreaks have been confirmed, by laboratory testing, from 6 Provinces of Papua New Guinea and another 2 Provinces have suspected outbreaks. This is the first time that chikungunya has been reported in Papua New Guinea. There is a high risk of the chikungunya outbreak spreading to other regions of the South Pacific due to the prevailing social, environmental and entomological factors.