Dengue virus infections among European travellers, 2015 to 2019

Abstract

Background Dengue is a disease with major impacts on public health in tropical and subtropical countries. In Europe, in the past decade, few autochthonous outbreaks were described. Aim We aimed to identify factors associated with frequency of dengue virus infection among European travellers and at assessing how surveillance data could support preparedness against autochthonous outbreaks within Europe. Methods We performed a descriptive analysis of travel-related dengue cases reported by European countries from 2015 through 2019. Using flight passenger data, we calculated travellers’ infection rates (TIR). We investigated the following associations: (i) between TIR and incidence rate in selected countries of infection and (ii) between number of travel-related cases and occurrence of autochthonous outbreaks within Europe. Results There were 11,478 travel-related dengue cases and the TIR was 2.8 cases per 100,000 travellers. Most cases were infected in Asia (71%), predominantly in south-eastern Asia. The TIR was highest among travellers returning from Asia (6.1/100,000). There was an association between the incidence rate in the country of infection and the TIR but no association between the number of travel-related cases and occurrence of autochthonous outbreaks in Europe. Conclusions The likelihood of infection in travellers is a function of the ongoing epidemiological situation in the country of exposure. The number of travel-related cases alone is not sufficient to estimate the likelihood of autochthonous outbreaks where vectors are present in Europe. Additional contributing factors such as adequate vectorial capacity and suitable environmental conditions are required.

Zika Virus Replicates in the Vagina of Mice with Intact Interferon Signaling

“…Though this represents only 1% of ZIKV cases in the US resulting in forward sexual transmission, this is likely an underestimate of the rate at which ZIKV-infected men transmit to their partners, since ~80% of ZIKV infections are asymptomatic and screening has been focused on symptomatic women with travel-related exposure. In contrast, DENV is the most prevalent human flavivirus infection, with an estimated >100 million infections worldwide annually (35) but there have been only two recently-described cases of DENV sexual transmission (36,37) despite tens of thousands of travel-associated DENV cases over the past >40 years (38)(39)(40)(41)(42)(43)(44)(45). Our data in mice suggest that the vagina may be a permissive site for replication of other flaviviruses, as we observed replication of other flaviviruses (SPOV and USUV) that do not generally replicate in wild-type mice (21,22).…”

Asymptomatic Arbovirus, Campylobacter but no Hepatitis E Infections in German Travelers to Asia

“…One reason for this lack of information is that most studies on the subject are retrospective in nature because they rely on surveillance data or spontaneously reported, symptomatic infections [ 14,15 , 16 , 17 ]. To overcome this hurdle, one study on Dengue virus (DENV) combined infection numbers with ight passenger data and calculated an incidence below one percent [ 18 ]. Another, also on DENV, used mathematical modeling to calculate an incidence between 0.2% and 0.91%, depending on the length of stay in an endemic region [ 19 ].…”

Comparative efficacy trials with alcohol added d‐phenothrin formulations against Aedes aegypti under open‐field condition

“…5,6 These characteristics give it increased ability to transmit pathogens to humans, leading to the autochthonous outbreaks of dengue in the European region. 7,8 Along with other species in the genus, including Aedes albopictus, Aedes japonicus, and Aedes koreicus, Ae. aegypti has since been established as an invasive mosquito specie (IMS) in Europe.…”

“…It is highly anthropophilic, with high preference for human odours, high feeding rates on humans and affinity to urbanized areas 5,6 . These characteristics give it increased ability to transmit pathogens to humans, leading to the autochthonous outbreaks of dengue in the European region 7,8 . Along with other species in the genus, including Aedes albopictus , Aedes japonicus , and Aedes koreicus , Ae.…”