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First identified in 1947, Zika virus took roughly 70 years to cause a pandemic unusually associated with virus-induced brain damage in newborns. Zika virus is transmitted by mosquitoes, mainly Aedes aegypti, and secondarily, Aedes albopictus, both colonizing a large strip encompassing tropical and temperate regions. As part of the international project ZIKAlliance initiated in 2016, 50 mosquito populations from six species collected in 12 countries were experimentally infected with different Zika viruses. Here, we show that Ae. aegypti is mainly responsible for Zika virus transmission having the highest susceptibility to viral infections. Other species play a secondary role in transmission while Culex mosquitoes are largely non-susceptible. Zika strain is expected to significantly modulate transmission efficiency with African strains being more likely to cause an outbreak. As the distribution of Ae. aegypti will doubtless expand with climate change and without new marketed vaccines, all the ingredients are in place to relive a new pandemic of Zika., (© 2022. The Author(s).)

Background: Like many countries from the Americas, Cuba is threatened by Aedes aegypti-associated arboviruses such as dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) viruses. Curiously, when CHIKV was actively circulating in the region in 2013-2014, no autochthonous transmission of this virus was detected in Havana, Cuba, despite the importation of chikungunya cases into this city. To investigate if the transmission ability of local mosquito populations could explain this epidemiological scenario, we evaluated for the first time the vector competence of two Ae. aegypti populations (Pasteur and Párraga) collected from Havana for dengue virus type 1 (DENV-1), CHIKV, and ZIKV., Methodology/principal Findings: Mosquito populations were fed separately using blood containing ZIKV, DENV-1, or CHIKV. Infection, dissemination, and transmission rates, were estimated at 3 (exclusively for CHIKV), 7, and 14 days post exposure (dpe) for each Ae. aegypti population-virus combination. Both mosquito populations were susceptible to DENV-1 and ZIKV, with viral infection and dissemination rates ranging from 24-97% and 6-67% respectively. In addition, CHIKV disseminated in both populations and was subsequently transmitted. Transmission rates were low (<30%) regardless of the mosquito population/virus combination and no ZIKV was detected in saliva of females from the Pasteur population at any dpe., Conclusions/significance: Our study demonstrated the ability of Ae. aegypti from Cuba to transmit DENV, ZIKV, and CHIKV. These results, along with the widespread distribution and high abundance of this species in the urban settings throughout the island, highlight the importance of Ae. aegypti control and arbovirus surveillance to prevent future outbreaks., Competing Interests: The authors have declared that no competing interests exist.

In France, diphtheria tetanus and inactivated polio vaccine (DT-IPV) coverage and immunization are insufficient in the elderly and decrease with age. The principal objective of this study was to assess the impact of a strategy of catch-up DT-IPV vaccination during hospitalization in people over the age of 65 years in central France (the Sarthe region). We performed a prospective, single-center, cluster-randomized study (four hospital wards). We included patients aged ≥65 years, without mental impairment, contraindication and who accepted to participate, hospitalized in the internal medicine wards in Le Mans Hospital from 28 May 2018 to 27 May 2019. The DT-IPV vaccination status of the patients was determined at inclusion and the wards were randomized (intervention and control). In the intervention group, vaccination was up-dated during hospitalization. In case of temporary contraindication, vaccination was prescribed at hospital discharge. Patients hospitalized in the control wards received oral information only. Final immunization status was determined by calling the patient's general practitioner two months after hospital discharge. One hundred and fifty seven patients were included: 73 in the intervention and 84 in the control arm. Baseline immunization coverage was 46.5%. Vaccination coverage increased from 56.2% to 80.8% in the intervention group and from 38.1% to 40.5% in the control group ( p < 0.001). Having received sufficient information from the general practitioner was the only factor associated with vaccination being up-to-date in uni- and multivariate analysis: OR = 5.07 [2.45-10.51]. In a setting of low vaccination coverage DT-IPV vaccination during hospitalization is an effective catch-up strategy.

Zika virus (ZIKV) is an arbovirus that has dramatically spread in South America and the Caribbean regions since 2015. The majority of vector incrimination studies available for ZIKV showed that Aedes aegypti mosquitoes are important vectors for this virus. However, several reports suggest that Culex quinquefasciatus mosquitoes may be implicated in ZIKV transmission in certain urban settings. In the present study, we evaluated the vector competence for ZIKV of Cx. quinquefasciatus and Ae. aegypti mosquitoes from Guadeloupe using African, American and Asian strains. The results demonstrated that Cx. quinquefasciatus is refractory to ZIKV infection whatever the strain tested at 7, 14 or 21 days post-infection (dpi), while ZIKV transmission was recorded in Ae. aegypti for all the three strains. The African ZIKV strain was better transmitted by Ae. aegypti (∼ 50% mean transmission efficiency) and with a shorter incubation period (7 dpi) when compared to the Asian and American strains (<14% transmission efficiency; incubation period of 14-21 dpi). Taken together, these results suggest that only Ae. aegypti mosquitoes are involved in urban ZIKV transmission in Guadeloupe and highlight a higher infectiousness of the African ZIKV strain in this mosquito species when compared to the Asian and American ones.

Background: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry technology (MALDI-TOF MS) is an innovative tool that has been shown to be effective for the identification of numerous arthropod groups including mosquitoes. A critical step in the implementation of MALDI-TOF MS identification is the creation of spectra databases (DB) for the species of interest. Mosquito legs were the body part most frequently used to create identification DB. However, legs are one of the most fragile mosquito compartments, which can put identification at risk. Here, we assessed whether mosquito thoraxes could also be used as a relevant body part for mosquito species identification using a MALDI-TOF MS biotyping strategy; we propose a double DB query strategy to reinforce identification success., Methods: Thoraxes and legs from 91 mosquito specimens belonging to seven mosquito species collected in six localities from Guadeloupe, and two laboratory strains, Aedes aegypti BORA and Aedes albopictus Marseille, were dissected and analyzed by MALDI-TOF MS. Molecular identification using cox1 gene sequencing was also conducted on representative specimens to confirm their identification., Results: MS profiles obtained with both thoraxes and legs were highly compartment-specific, species-specific and species-reproducible, allowing high identification scores (log-score values, LSVs) when queried against the in-house MS reference spectra DB (thorax LSVs range: 2.260-2.783, leg LSVs range: 2.132-2.753)., Conclusions: Both thoraxes and legs could be used for a double DB query in order to reinforce the success and accuracy of MALDI-TOF MS identification.