Disseminated infection rate, transmission rate and transmission efficiency to CHIKV strains of <i>Ae. albopictus</i> from France (AL-CSM) and <i>Ae. aegypti</i> from India (AA-INDIA) at different days post-infection.

<p>DIR: Disseminated infection rate corresponding to the proportion of mosquitoes with infected head among tested ones; TR: Transmission rate corresponding to the proportion of mosquitoes with infectious saliva among mosquitoes able to disseminate the virus beyond the midgut barrier; TE: Transmission efficiency corresponding to the proportion of mosquitoes with infectious saliva among tested ones; In parenthesis for DIR, number of mosquitoes analyzed; In parenthesis for TR, number of mosquitoes able to disseminate the virus beyond the midgut; In parenthesis for TE, number of mosquitoes analyzed; ^† Strain isolated from a French autochthonous case; ^‡ Strain isolated from a French imported case.</p

Transmission of CHIKV in saliva of <i>Ae. albopictus</i> from France (AL-CSM) and <i>Ae. aegypti</i> from India (AA-India).

<p>At days 3, 6, 9, and 14 after infection with an infectious blood-meal, mosquitoes were sacrificed and saliva was collected from individual mosquitoes and titrated by focus fluorescent assay on C6/36 <i>Ae. albopictus</i> cells. Two viral strains were tested: (A) CHIKV-1630 strain that circulated in India in 2010 and (B) CHIKV-1909 strain isolated from a CHIKV autochthonous case from Fréjus. Error bars refer to the standard error between different mosquitoes.</p

Dissemination of CHIKV in <i>Ae. albopictus</i> from France (AL-CSM) and <i>Ae. aegypti</i> from India (AA-India).

<p>At days 3, 6, 9, and 14 after infection with an infectious blood-meal, mosquitoes were sacrificed and heads were removed for viral titration. The number of infectious particles per head homogenate was estimated by focus fluorescent assay on C6/36 <i>Ae. albopictus</i> cells. Two viral strains were tested: (A) CHIKV-1630 strain that circulated in India in 2010 and (B) CHIKV-1909 strain isolated from a CHIKV autochthonous case from Fréjus. Error bars refer to the standard error between different mosquitoes.</p

Transmission of DENV in saliva of <i>Ae. albopictus</i> from France (AL-CSM) and <i>Ae. aegypti</i> from Martinique (AA-Martinique).

<p>At days 9 and 14 after infection with an infectious blood-meal provided, mosquitoes were sacrificed and saliva was collected from individual mosquitoes and titrated by focus fluorescent assay on C6/36 <i>Ae. albopictus</i> cells. Two viral strains were tested: (A) DENV-2025 strain that circulated in Martinique in 2010 and (B) DENV-1806 strain isolated from a DENV autochthonous case from Nice. Error bars refer to the standard error between different mosquitoes.</p

Disseminated infection rate, transmission rate and transmission efficiency to DENV strains of <i>Ae. albopictus</i> from France (AL-CSM) and <i>Ae. aegypti</i> from Martinique (AA-Martinique) at two days post-infection.

<p>DIR: Disseminated infection rate corresponding to the proportion of mosquitoes with infected head among tested ones; TR: Transmission rate corresponding to the proportion of mosquitoes with infectious saliva among mosquitoes able to disseminate the virus beyond the midgut barrier; TE: Transmission efficiency corresponding to the proportion of mosquitoes with infectious saliva among tested ones; In parenthesis for DIR, number of mosquitoes analyzed; In parenthesis for TR, number of mosquitoes able to disseminate the virus beyond the midgut; In parenthesis for TE, number of mosquitoes analyzed;</p>†<p>Strain isolated from a French autochthonous case;</p>‡<p>Strain isolated from a French imported case.</p

Map of Cameroon: main climatic zones and location of the 3 study sites.

<p>Map of Cameroon: main climatic zones and location of the 3 study sites.</p

Dengue seroprevalence according to (a) serotypes and (b) age groups in the three main cities in Cameroon in 2006–2007.

<p>Dengue seroprevalence according to (a) serotypes and (b) age groups in the three main cities in Cameroon in 2006–2007.</p

Sero-epidemiologic survey of dengue in Yaounde, Cameroon in 2006–2007: Multivariate analysis using logistic regression with random effect.

<p>Sero-epidemiologic survey of dengue in Yaounde, Cameroon in 2006–2007: Multivariate analysis using logistic regression with random effect.</p

Rainfall in Libreville, Gabon from September 2006 to September 2007 (grey bars) and monthly numbers of suspected Chikungunya cases in Gabon, March 2006–September 2007 (black curve).

<p>Rainfall in Libreville, Gabon from September 2006 to September 2007 (grey bars) and monthly numbers of suspected Chikungunya cases in Gabon, March 2006–September 2007 (black curve).</p

Location of mosquito trapping sites both inside [4]–[9] and outside [1]–[3] the military camp of French armed forces in Libreville, Gabon.

<p>Location of mosquito trapping sites both inside <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0004691#pone.0004691-Schuffenecker1" target="_blank">[4]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0004691#pone.0004691-Kuniholm1" target="_blank">[9]</a> and outside <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0004691#pone.0004691-Ross1" target="_blank">[1]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0004691#pone.0004691-Chretien1" target="_blank">[3]</a> the military camp of French armed forces in Libreville, Gabon.</p