FrenchPolydata.xlsx

35 years of laboratory confirmed dengue cases from French Polynesia with information on age, island and geographical sub-division of each case.</div

Effect of using centrifugal filter device on DENV titers in C6/36 cell-culture supernatants.

<p>DENV titers in C6/36 cell-culture supernatants were evaluated before and after concentration with Centricon Plus-70 centrifugal filter devices (CFD; Millipore, Germany). Viral titers were significantly higher after CFD concentration (Paired t-test, P = 0.0001) with an evolution of the median titer (line) from 6.00 to 8.50 log₁₀ TCID₅₀/mL. DENV = Dengue virus.</p

CHIKV infection rate, dissemination and transmission efficiencies at 2, 6, 9, 14 and 21 days post-infection.

<p>CHIKV infection rate, dissemination and transmission efficiencies at 2, 6, 9, 14 and 21 days post-infection.</p

Vector Competence of French Polynesian <i>Aedes aegypti</i> and <i>Aedes polynesiensis</i> for Zika Virus

<div><p>Background</p><p>In 2013–2014, French Polynesia experienced for the first time a Zika outbreak. Two <i>Aedes</i> mosquitoes may have contributed to Zika virus (ZIKV) transmission in French Polynesia: the worldwide distributed <i>Ae</i>. <i>aegypti</i> and the Polynesian islands-endemic <i>Ae</i>. <i>polynesiensis</i> mosquito.</p><p>Methodology/Principal Findings</p><p>To evaluate their vector competence for ZIKV, mosquitoes were infected <i>per os</i> at viral titers of 7 logs tissue culture infectious dose 50%. At several days post-infection (dpi), saliva was collected from each mosquito and inoculated onto C6/36 mosquito cells to check for the presence of ZIKV infectious particles. Legs and body of each mosquito were also collected and submitted separately to RNA extraction and ZIKV RT-PCR. In <i>Ae</i>. <i>aegypti</i> the infection rate was high as early as 6 dpi and the dissemination efficiency get substantial from 9 dpi while the both rates remained quite low in <i>Ae</i>. <i>polynesiensis</i>. The transmission efficiency was poor in <i>Ae</i>. <i>aegypti</i> until 14 dpi and no infectious saliva was found in <i>Ae</i>. <i>polynesiensis</i> at the time points studied.</p><p>Conclusions/Significance</p><p>In our experimental conditions, the late ability of the French Polynesian <i>Ae</i>. <i>aegypti</i> to transmit ZIKV added by the poor competence of <i>Ae</i>. <i>polynesiensis</i> for this virus suggest the possible contribution of another vector for the propagation of ZIKV during the outbreak, in particular in remote islands where <i>Ae</i>. <i>polynesiensis</i> is predominating.</p></div

ZIKV infection rate, dissemination and transmission efficiencies in <i>Ae</i>. <i>aegypti</i> and <i>Ae</i>. <i>polynesiensis</i> from French Polynesia.

<p>ZIKV infection rate, dissemination and transmission efficiencies in <i>Ae</i>. <i>aegypti</i> and <i>Ae</i>. <i>polynesiensis</i> from French Polynesia.</p

Progression trends of CHIKV dissemination and transmission efficiencies in <i>Ae</i>. <i>aegypti</i> and <i>Ae</i>. <i>polynesiensis</i>.

<p>Statistically significant differences between two successive days post-infection are shown by asterisks (** = p<0.01). CHIKV dissemination efficiency showed a dramatic increase in <i>Ae</i>. <i>aegypti</i> from 6 to 9 dpi.</p

Infected <i>Aedes aegypti</i> rate (%) at 14 days post-intake of an artificial infectious blood-meal prepared either with initial (trial 1a) or CFD-concentrated DENV supernatants (trials 1b-8).

<p>Infected <i>Aedes aegypti</i> rate (%) at 14 days post-intake of an artificial infectious blood-meal prepared either with initial (trial 1a) or CFD-concentrated DENV supernatants (trials 1b-8).</p

Vector Competence of <i>Aedes aegypti</i> and <i>Aedes polynesiensis</i> Populations from French Polynesia for Chikungunya Virus

<div><p>Background</p><p>From October 2014 to March 2015, French Polynesia experienced for the first time a chikungunya outbreak. Two <i>Aedes</i> mosquitoes may have contributed to chikungunya virus (CHIKV) transmission in French Polynesia: the worldwide distributed <i>Ae</i>. <i>aegypti</i> and the Polynesian islands<i>-</i>endemic <i>Ae</i>. <i>polynesiensis</i> mosquito.</p><p>Methods</p><p>To investigate the vector competence of French Polynesian populations of <i>Ae</i>. <i>aegypti</i> and <i>Ae</i>. <i>polynesiensis</i> for CHIKV, mosquitoes were exposed <i>per os</i> at viral titers of 7 logs tissue culture infectious dose 50%. At 2, 6, 9, 14 and 21 days post-infection (dpi), saliva was collected from each mosquito and inoculated onto C6/36 mosquito cells to check for the presence of CHIKV infectious particles. Legs and body (thorax and abdomen) of each mosquito were also collected at the different dpi and submitted separately to viral RNA extraction and CHIKV real-time RT-PCR.</p><p>Results</p><p>CHIKV infection rate, dissemination and transmission efficiencies ranged from 7–90%, 18–78% and 5–53% respectively for <i>Ae</i>. <i>aegypti</i> and from 39–41%, 3–17% and 0–14% respectively for <i>Ae</i>. <i>polynesiensis</i>, depending on the dpi. Infectious saliva was found as early as 2 dpi for <i>Ae</i>. <i>aegypti</i> and from 6 dpi for <i>Ae</i>. <i>polynesiensis</i>. Our laboratory results confirm that the French Polynesian population of <i>Ae</i>. <i>aegypti</i> is highly competent for CHIKV and they provide clear evidence for <i>Ae</i>. <i>polynesiensis</i> to act as an efficient CHIKV vector.</p><p>Conclusion</p><p>As supported by our findings, the presence of two CHIKV competent vectors in French Polynesia certainly contributed to enabling this virus to quickly disseminate from the urban/peri-urban areas colonized by <i>Ae</i>. <i>aegypti</i> to the most remote atolls where <i>Ae</i>. <i>polynesiensis</i> is predominating. <i>Ae</i>. <i>polynesiensis</i> was probably involved in the recent chikungunya outbreaks in Samoa and the Cook Islands. Moreover, this vector may contribute to the risk for CHIKV to emerge in other Polynesian islands like Fiji, and more particularly Wallis where there is no <i>Ae</i>. <i>aegypti</i>.</p></div

Number of engorged mosquito females obtained the day of infection and mortality rate during the following days.

<p>Number of engorged mosquito females obtained the day of infection and mortality rate during the following days.</p

Supplementary Methods, Figures, and Tables.

(PDF)</p