Zika Virus Transmission from French Polynesia to Brazil
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4593458/
To the Editor: Campos et al. (1)
reported a Zika virus (ZIKV) outbreak in Brazil in 2015. This response
adds complementary data related to the propagation of this mosquitoborne
disease.
To date, the largest ZIKV outbreak occurred in
French Polynesia during 2013–2014. The outbreak spread to other Pacific
Islands: New Caledonia, Cook Islands, Easter Island, Vanuatu, and
Solomon Islands (2).
The origin of introduction of ZIKV to French Polynesia remains unknown;
introduction of ZIKV in New Caledonia was after imported cases from
French Polynesia (3);
introduction to Easter Island was suspected to have occurred among
attendees of the annual Tapati festival, including those from French
Polynesia (4).
The virus was likely transmitted to New Caledonia, Cook Islands, and
Easter Island when infected travelers from French Polynesia were bitten
by vectors while on the islands. Frequent travel between New Caledonia
and Vanuatu is likely related to the introduction of ZIKV in the latter
country.
Phylogenetic studies showed
that the closest strain to the one that emerged in Brazil was isolated
from samples from case-patients in French Polynesia and spread among the
Pacific Islands (1);
both strains belong to the Asian lineage. It has been assumed that ZIKV
was introduced to Brazil during a World Cup soccer competition in 2014 (5),
although no ZIKV-endemic Pacific countries competed. However, in August
2014, the Va’a World Sprint Championship canoe race was held in Rio de
Janeiro, Brazil. Four Pacific countries (French Polynesia, New
Caledonia, Cook Islands, and Easter Island) in which ZIKV circulated
during 2014 had teams engaged in this contest in several categories.
These data combined with phylogenetic studies by Zanluca et al. (5)
suggest that ZIKV introduction in Brazil may have been a consequence of
this event. In areas where potential vectors are present, vigilance
should be enhanced to detect imported cases of ZIKV, and laboratory
capacity to confirm suspected ZIKV infections should be strengthened.
Footnotes
Suggested citation for this article: Musso D. Zika virus transmission from French Polynesia to Brazil [letter]. Emerg Infect Dis. 2015 Oct [date cited]. http://dx.doi.org/10.3201/eid2110.151125
References
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2. Musso D, Cao-Lormeau V, Gubler D. Zika virus: following the path of dengue and chikungunya?
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Co-infection with Zika and dengue viruses in 2 patients, New Caledonia, 2014.
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5. Zanluca C, de Melo VCA, Mosimann ALP, dos Santos GIV, dos Santos CND, Luz K. First report of autochthonous transmission of Zika virus in Brazil.
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