Clinical Research Directory

ARBOspot: Characterization of Arbovirus Specific T Cell Response in Patients by Using Enzyme Linked Immunospot (ELISpot) Assays

Arboviruses (arthropod-borne viruses), are a group of RNA viruses that are transmitted to vertebrate hosts by hematophagous arthropods like mosquitos, ticks, and sandflies. In Italy, arboviruses pose a considerable public health concern because of their potential to infect humans and cause severe emergent or re-emergent diseases. Over the past few decades, arboviruses have already been responsible for epidemic outbreaks in Italy, and travels increase the risk of introducing new species previously confined to tropical and sub-tropical regions. Some arboviral infections, like West Nile Virus (WNV), Toscana Virus (TOSV), Sandfly Fever Sicily Virus (SFSV), Sandfly Fever Naples Virus (SFNV), Usutu Virus (USUV), and tick-borne encephalitis virus (TBEV), are considered endemic in Italy. Others, such as Chikungunya Virus (CHIKV), Dengue Virus (DENV), Zika Virus (ZIKV), Yellow Fever Virus (YFV) and Japanese encephalitis Virus (JEV) are under surveillance since imported infections could lead to local outbreaks and subsequent endemic circulation in Italy. Moreover, the increased global travel and unpredictable climate changes could facilitate the spread of arboviral infections. Adequate diagnostic tests play a crucial role in disease surveillance, identifying potential associations between previous infections and chronic diseases and controlling outbreaks by breaking transmission chains. Furthermore, immunological tests can help predict disease severity in healthy and immunocompromised subjects and identify patients at risk for severe disease during secondary infections. In parallel with direct molecular diagnosis tests, the development of an immunological test capable of determining specific arbovirus T cell response may be useful for diagnostic as well as for epidemiological and investigative purposes. Furthermore, its development provides a set of initial knowledge on which to base the construction of other immunological tests for future emerging viruses, providing tools to counter new epidemic outbreaks. At the same time, the evaluation of immune response is necessary in order to control and contain the spread of these viruses. In conclusion, the present study aims to investigate immunological responses in patients infected with endemic arboviruses circulating in Italy those that could potentially emerging in the future. Molecular tests have a reduced detectability window in biological samples, which is why often they are not useful for making a diagnosis. Serological tests can give cross-reactivity phenomena between some arboviruses, making differential diagnosis difficult and often inconclusive. Objective is to assess sensitivity of immunological assays for arboviruses-specific T Cell Response (ARBOspot) in order to use them in combination with conventional diagnostic methods.

"Pregnancy and Viral Infections: Impact on Pregnant Women and Their Children. French Prospective Cohort"

The VIROPREG study is a French prospective multicenter cohort study that aims to assess the impact of viral infections and antiviral treatments received during pregnancy on maternal and child health. The study focuses on both chronic viral infections: human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV)\] and on arbovirus infections. This study aims at investigating the following research questions: * What is the rate of mother-to-child transmission for each virus? * What are the effects of maternal infection on (i) pregnancy outcomes, (ii) the mother's physical and psychological health, and (iii) the fetus' health and development, with a focus on long-term psychomotor development in children born to women living with HIV? * What is the impact of antiretroviral and/or antiviral prophylactic and/or therapeutic treatments administered during pregnancy on maternal and fetal health? Mother-child pairs will be followed from pregnancy through delivery and from birth until the child reaches 7 years of age. Each mother-child pair will be enrolled into one of four cohort groups based on the maternal infection. HIV Cohort: Pregnant women living with HIV who participate in the research will: * Be followed according to the routine care schedule from enrollment to post-natal visit usually scheduled in maternity after delivery (6-8 weeks post-partum) * Participate in additional follow-up by phone call or videoconference at 4- and 7-years post-partum for research purposes * Complete questionnaires at inclusion, delivery, 4- and 7- years postpartum * In case of breastfeeding, receive follow-up care aligned with routine schedules for up to 2 years postpartum, including 2 additional visits specifically for research at 2- and 3- months postpartum. * In selected cases: provide blood, umbilical cord blood, colostrum and breast milk samples during follow-up visits for research purposes (pharmacological and virological analyses). Children born to mothers living with HIV and who participate in the research will: * Be followed according to the routine care schedule from birth until 2 years of age * Participate in additional follow-up by phone call or videoconference, addressed to mothers, at 4- and 7- years of age for research purposes. HBV Cohort: Pregnant HBV-infected women who participate in the research will: * Be followed according to the routine care schedule from enrollment to post-natal visit usually scheduled in maternity after delivery (6- 8 weeks post-partum) * Complete questionnaires at inclusion and delivery * Provide blood samples during follow-up visits for research purposes. Children born to HBV-infected mothers and who participate in the research will: * Be followed according to the routine care schedule from birth to 2 years of age * Participate in additional follow-up for research purposes at 3 months and 18-24 months of age. HCV Cohort: Pregnant HCV-infected women who participate in the research will: * Be followed according to the routine care schedule from enrollment to post-natal visit usually scheduled in maternity after delivery (6 - 8 weeks post-partum) * Complete questionnaires at inclusion and delivery * Provide blood samples during follow-up visits for research purposes. Children born to HCV-infected mothers and who participate in the research will: * Be followed according to the routine care schedule from birth until 2 years of age * Attend additional follow-up visits scheduled at 3 and 9 months of age for research purposes. Arbovirus Cohort: Pregnant women infected with arbovirus who participate in the research will: * Be followed according to the routine care schedule from enrollment to delivery * Participate in additional follow-up for research purposes at 4 years after delivery. * In case of breastfeeding, women will be monitored for research purposes at Day 7 and Day 30 postpartum * Complete questionnaires at inclusion, Day 7-10 from the inclusion, delivery and 4 years after delivery * Provide blood, amniotic fluid, placenta, umbilical cord blood, colostrum and breast milk samples during follow-up visits for research purposes. Children born to mothers infected with arbovirus and who participate in the research will: * Be followed according to the routine care schedule from birth until 2 years of age. * Participate in additional follow-up for research purposes at inclusion, Day 7 and Day 30 after inclusion * Participate in additional follow-up by phone call or videoconference, addressed to mothers, at 4- and 7- years of age for research purposes.

Cohort Study of Arbovirus and Other Emerging Virus Infections in Fiji: AEVI-Fiji Cohort.

Background: Fiji, an archipelago in the South Pacific comprising 332 islands distributed among 4 health administrative divisions (Central, Western, Eastern, Northern), is particularly vulnerable to the (re-)emergence of arboviruses and respiratory viruses due to its sub-tropical climate, the presence of several mosquito vector species, and connections with many countries in the Pacific, Asia and North America. Over the past decades, the epidemiological landscape of arboviruses has shifted from the sequential circulation of each of the four dengue virus (DENV) serotypes to the emergence of Zika virus (ZIKV) and chikungunya virus (CHIKV), concomitantly to the concurrent circulation of multiple DENV serotypes. The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2020 significantly challenged Fiji's healthcare system, with the Delta variant alone accounting for approximately 700 deaths, while other respiratory viruses, such as influenza A and B, cause seasonal outbreaks. Despite these threats, comprehensive and up-to-date seroprevalence data remain scarce, limiting the capacity to inform and adapt public health policies. Methods: The cohort study of Arbovirus and other Emerging Virus Infections in Fiji (AEVI-Fiji cohort study) aims to estimate the prevalence of several arboviruses and respiratory viruses, track the evolution of individual immunity, and analyse transmission dynamics of these viruses within the Fijian population. This longitudinal study will span 38 months and will include about 900 willing participants aged six years and older, recruited from at least 210 households randomly selected across the Central Division. Four visits will be conducted 12 months apart in each household. During each visit, participants will complete a questionnaire capturing their demographic characteristics and history of infections with major arboviruses and respiratory viruses and will provide a blood sample for serological analysis. During the whole study period, participants with a suspected acute infection by an arbovirus or respiratory virus will be screened. Discussion: For the first time in Fiji, the AEVI-Fiji cohort study will generate longitudinal data to explore the determinants of both arbovirus and respiratory virus infections. The findings are expected to guide targeted public health strategies and enhance preparedness for future infectious disease threats in Fiji and the broader Oceania region.

The Interest of Systematic Screening for Dengue, Chikungunya, and Zika, in Malaria-negative Return Travelers

International travel has increased dramatically in recent years. Vector-borne pathologies such as malaria and arboviruses are common etiologies of post-travel fever, which are prevalent in similar geographical areas (tropical and intertropical). Arboviruses, for "arthropod-borne viruses," are transmitted by the bite of blood-sucking vectors (mosquitoes, ticks, or sandflies). The dengue, chikungunya, and zika viruses are transmitted through the bite of an infected Aedes mosquito (Aedes aegypti and Aedes albopictus). The establishment of Aedes albopictus (tiger mosquito), competent for transmitting these 3 viruses, since 2004 in mainland France and the transit of travelers carrying a virus allowed the appearance of the first autochthonous cases of dengue and zika. Each year, outbreaks of autochthonous cases of dengue fever are reported in the PACA, Occitanie, and Auvergne-Rhône Alpes regions, and a cluster of 3 Indigenous cases was reported in 2023 in the Paris region. Since 2014, the tiger mosquito has been established in Bas-Rhin. Between 2014 and 2022, the vector was detected in around thirty municipalities around Strasbourg. In a department where the spread of the tiger mosquito is evolving rapidly, these data remind us that only an early diagnosis, delivered quickly, allows effective vector control measures to avoid generating autochthonous transmission. In a previous study carried out at the Virology laboratory, we retrospectively analyzed the diagnosis of these 3 arboviruses after the exclusion of malaria in the context of recent travel over a period of 10 years (2014-2023). Among the 913 patients included, for 78% of cases (n=714), no testing for dengue, chikungunya, or zika was carried out, a proportion stable over 10 years. These three arboviruses seem underdiagnosed, and we assume, given our previous results, that 8 to 10% of patients for whom, in the context of recent travel, a test for malaria comes back negative are imported cases of dengue, chikungunya, or zika. At the end of this retrospective study, we want to evaluate this sub-diagnosis on a larger sample to propose a review of practices and the establishment of Arbovirus-malaria "reflex testing." Currently, no French or similar European data is available, allowing us to evaluate this under-diagnosis, which constitutes a significant risk of the emergence of indigenous clusters in our territory. The main objective of this study is to determine the infection rate by dengue, chikungunya, and zika viruses identified when the diagnosis is made after the exclusion of negative malaria in the context of recent travel among patients treated at the Strasbourg University Hospitals between January 1, 2024, and December 31, 2025. The secondary objectives of this work are as follows: Estimate the prevalence of different clinical symptoms (patient medical records) in retrospectively identified cases of dengue, chikungunya, and zika. * Evaluate the onset time of symptoms in relation to the date of return/arrival from the area of stay of retrospectively identified cases of dengue, chikungunya, and zika. * Evaluate the delay in the appearance of symptoms in relation to the date of taking the initial sample (the one leading to the diagnosis of negative malaria) of retrospectively identified cases of dengue, chikungunya, and zika. * Study the laboratory results associated with the initial management of the patient (biochemical assessment and blood count) of retrospectively identified cases of dengue, chikungunya, and zika. * Study the distribution of areas, periods, and reasons for staying in retrospectively identified dengue, chikungunya, and zika cases. Study the municipalities of residence of positive cases in the areas where the tiger mosquito is established.

Improving Disease Prevention Strategies by Integrating Socio-spatial Characterization of Human Mobility

In contrast to the trend expected based on existing prediction models, dengue incidence was historically low during the pandemic mobility restrictions of 2020-2021 in most dengue endemic countries. This highlights that current transmission models do not correctly take human mobility into account. Within a pilot-study in Cienfuegos, South-Central Cuba, we will characterise the epidemiological spread and distribution of dengue outbreaks (2012-2025) in districts repeatedly involved in previous dengue outbreaks as initiating, case-concentrating or transmission sustaining areas. This will be linked with fine-grained mobility data and socio-spatial characterizations of commuting flows and population hubs where people are concentrated during day-time (time when transmission happens). This information, together with entomological and environmental risk-data, will be used to i) improve the accuracy of mathematical dengue models, ii) better understand the transmission process and iii) inform and improve the design of disease control strategies. The project will contribute to much-needed evidence-based guidance for public health actors on improved prevention strategies of epidemics dispersion and where and when to implement control measures.

Virological and Immunological Determinants of Arbovirus Infection in New Caledonia

Arboviruses, diseases transmitted to humans by the bite of an insect vector, are a major public health problem, particularly in tropical and sub-tropical countries. In New Caledonia, dengue epidemics are recurrent and may be associated with the co-circulation of other arboviruses such as Zika or chikungunya. The virological determinants which condition the occurrence of these epidemics may be linked to an increased vectorial competence of the vector mosquito Aedes aegypti for a particular viral isolate. In fact, the Aedes aegypti mosquito is infected by making a blood meal on a person infected with an arbovirus. The virus infects its digestive tract, then spreads throughout the mosquito's body until it reaches its salivary glands. The virus is then present in the saliva and will be injected into the human host during a new blood meal. Some viral variants are best transmitted by Aedes aegypti. In general, the study of this vectorial competence is carried out by experiments in the laboratory during which an artificial blood meal composed of mammalian blood (human, rabbit, etc.) is mixed with a viral stock. Carrying out deported blood meals during which blood collected from patients infected with an arbovirus is used to gorge mosquitoes makes it possible to place oneself in experimental conditions as close as possible to the natural cycle of transmission of arboviruses. In the human host, cells of the myeloid lineage present in the peripheral blood constitute preferred targets of replication for arboviruses. At the same time, the peripheral blood cells of patients are activated in response to infection and secrete many soluble factors released into the blood of patients. The study of blood samples from patients infected with arboviruses is therefore of prime importance for understanding both the replicative mechanisms of arboviruses but also the immune response they induce.

Genetic Evolution of Arboviruses in New Caledonia Between 1995 and 2024 and Impact of Wolbachia

Arboviruses, diseases transmitted to humans by the bite of an insect vector, are a major public health problem, especially in tropical and sub-tropical countries. A promising strategy aimed at blocking the circulation of arboviruses is to release Aedes aegypti mosquitoes carrying the endosymbiotic bacterium Wolbachia. In 2019, the Wolbachia strategy was implemented in Nouméa as part of the World Mosquito Program. This intervention will modify the epidemiological profile of arboviruses in New Caledonia. Epidemiological surveillance of arboviruses requires molecular characterization of the virus contained in the serum obtained from the blood collected from patients. This molecular characterization by RNA isolation techniques, RT-qPCR monitoring and sequencing allows the construction of phylogenetic trees. In the context of the implementation of the World Mosquito Program in Nouméa, the investigators plan to follow the molecular evolution of arboviruses, over the period preceding the releases of mosquitoes carrying Wolbachia (from 1995 to 2019) then over a period of 5 years. following the releases. At the same time, the virus can be isolated by cell culture techniques and in vitro infections, allowing its study in vitro in cells or in vivo in mosquitoes. This study allows us to measure the impact of the Wolbachia strategy on the evolution of the virus's ability to replicate in cells in the presence of Wolbachia and to be transmitted by the mosquito.