Chikungunya in Pacific Region

​As of 15 October, 59 chikungunya cases have been reported in the commune of Teva i Uta, Tahiti, French Polynesia [1]. No fatalities had been associated with this event. According to media, the event is reaching now the epidemic level with 200 suspected cases in several locations on the Tahiti island [2]. Authorities have implemented vector control in the affected sites and epidemiological surveillance has been reinforced. It is the first time that the disease is locally transmitted in French Polynesia. The extension of this outbreak is expected as competent Aedes vectors are present in French Polynesia and the local population is immunologically naïve with regards to chikungunya infection.

 

ECDC comment:

Occurrence of chikungunya outbreaks in French Polynesia is not unexpected as competent vectors are present. Chikungunya outbreaks have occurred in the past in the Pacific region in New Caledonia (2011), Papua New Guinea (2012), Yap State Micronesia (2013), and in Samoa, Tonga and Tokelau islands (since June 2014).

 

The possibility for importation of the virus in the Pacific region is possible as illustrated by the case-report of a 60-year-old woman who returned to French Polynesia from Guadeloupe in May 2014 diagnosed with a symptomatic chikungunya infection [3][4]. This case had been in contact with family members affected by chikungunya in Guadeloupe prior to departure. Other introduction of the virus might occur from Asian countries where chikungunya virus circulation were described, notably in Indonesia (West Java) [5].

 

In the recent study by Roth et al. [6], 28 outbreaks and viral circulation events of dengue, chikungunya and Zika virus have been identified between January 2012 and Mid-September 2014. The study highlights that mosquito-borne outbreaks are increasing in frequency leading to possible co-circulation of dengue (different serotypes), chikungunya and Zika viruses. Overall, the authors consider that the observed trend events of mosquito-borne outbreaks in pacific island will remains for several years.

 

In conclusion, the public health burden of mosquito-borne diseases should be considered for countries and territories in the Pacific region. Furthermore, scientific studies are justified especially on the effect of sequential and parallel infections with different mosquito-borne viruses and its potential association with neurological syndrome [7], and on vector competence and vector control strategies.

 

 

References:

1. INVS. Bulletin Hebdomadaire International du 8 au 14 octobre 20142014.

2. Le Monde. Chikungunya : le stade épidémique atteint en Polynésie. 2014 [cited 2014 Oct 16].

3. Roth A, Hoy D, Horwood PF, Ropa B, Hancock T, Guillaumot L, et al. Preparedness for threat of chikungunya in the pacific. Emerg Infect Dis. 2014 Aug;20(8).

4. Nhan T, Claverie A, Roche C, Teiseer A, Colleuil M, Baudet J, et al. Chikungunya Virus Imported into French Polynesia, 2014. Emerg Infect Dis. 2014;20(10).

5. Kosasih H, de Mast Q, Widjaja S, Sudjana P, Antonjaya U, Ma'roef C, et al. Evidence for endemic chikungunya virus infections in Bandung, Indonesia. PLoS Negl Trop Dis. 2013;7(10):e2483.

6. Roth A, Mercier A, Lepers C, Hoy D, Duituturaga S, Benyon E, et al. Concurrent outbreaks of dengue, chikungunya and Zika virus infections – an unprecedented epidemic wave of mosquito-borne viruses in the Pacific 2012–20142014; 19(41)

7. Oehler E, Watrin L, Larre P, Leparc-Goffart I, Lastere S, Valour F, et al. Zika virus infection complicated by Guillain-Barre syndrome--case report, French Polynesia, December 2013. Euro Surveill. 2014;19(9).