Biology subjects

Guerrini, L.

Publications and source records attributed to Guerrini, L..

5 recordsLinked to original sources

bioRxiv2025

Risk factors associated with tick infestation and Ehrlichia ruminantium amongst cattle in Guadeloupe, French West Indies.

Ehrlichia ruminantium infection and infestations by two tick species, Amblyomma variegatum and Rhipicephalus microplus, are a major threat to the livestock sector in Guadeloupe. This study examined specific tick infestations for 261 cattle from 73 farms on the archipelagos three largest islands, Basse-Terre, Grande-Terre and Marie-Galante. A questionnaire was implemented to gather information on farming practices and livestock characteristics in order to identify potential risk factors associated with the presence of antibodies against E. ruminantium and the abundance of ticks in livestock. A total of 81% of the inspected cattle were found to be infested with ticks, with a prevalence of 69% for A. variegatum and 47% for R. microplus. At farm level, 96% of farms had infested animals, 84% of which were infested with A. variegatum and 73% with R. microplus. Risk factors were first explored using multiple correspondence analysis (MCA) followed by a generalized linear model at the farm level, and finally a generalized linear mixed model at cattle level. MCA revealed that non-traditional breeding system, with free-grazing animals, were associated with serological evidence of E. ruminantium circulation and also higher tick infestations. The utilisation of green fodder had a significant impact on the prevalence of seropositive animals and tick abundance. Differences in infestation were observed between the three largest islands of Guadeloupe and have been discussed in this article. The frequency of acaricide bathing and its interaction with acaricide alternation appeared to be significant factors in the mitigation of tick infestations in cattle. However, this study highlights the potential emergence of acaricide resistance within tick populations in Guadeloupe.

microbiology↗

bioRxiv2025

Prevalence of Heartwater in Guadeloupe (2024): Stable endemicity and Evidence of Spread to Les Saintes

Heartwater is a tick-borne disease caused by Ehrlichia ruminantium and remains endemic in the Guadeloupe archipelago. While previous data from 1989 suggested a seroprevalence of 22% in cattle, no updated figures were available for livestock, and certain islands such as Les Saintes were considered disease-free. This study aimed to update the sero-epidemiological status of heartwater in cattle and goats across Guadeloupe in 2024. Blood samples were collected from 261 cattle and 135 goats from all islands. Serological testing using the MAP1B ELISA was performed, and true seroprevalence was estimated using a simplified stochastic model that accounts for test sensitivity, specificity, and sample uncertainty. The mean cattle seroprevalence was estimated at 28% (95% CI [22-34%]), with no significant differences between Basse-Terre, Grande-Terre, and Marie-Galante. Importantly, seropositive goats were identified on all major islands, including Les Saintes. Our findings suggest that heartwater remains endemically stable in Guadeloupe since the 1980s and reveal for the first time its serological presence in Les Saintes. These results emphasize the importance of strengthening regional surveillance systems, including veterinary reporting, serological monitoring, and coordinated efforts to prevent further spread across the Caribbean.

immunology↗

bioRxiv2025

Downscaling local distribution of cattle over Guadeloupe archipelago: an adapted method for disaggregating census data

Gridded livestock distribution datasets have been produced for several years and are used in various fields, including epidemiology, livestock impact assessment, and territory management. Those datasets are based on census conducted at national/sub-national scale which are then downscaled using machine learning algorithm and relevant spatial-explicit environmental predictors. The most known dataset of livestock disaggregated observations is the Gridded Livestock of the World (GLW), which produces global maps of livestock density at 10 km spatial resolution for several livestock species. Though this spatial resolution can be appropriate to describe livestock distribution at the global scale, it inherently leads to a coarse representation of breeding species density for smaller territories such as the Caribbean Islands. In this study, we propose an adaptation of the GLW methodology that accounts for the spatial autocorrelation in observed cattle distribution, thereby better capturing the specific characteristics of geographically limited areas such as the Guadeloupean archipelago. Cattle census data were collected for the 32 municipalities of the archipelago and associated to environmental predictors derived from remote sensing and land cover datasets. Together with the Random Forest (RF) algorithm used in the standard GLW methodology, we tested the performance of a Geographical Random Forest (GRF), a novel methodology allowing for taking into account the spatial autocorrelation of the response variable. The GRF algorithm demonstrated significantly better performance compared to the RF algorithm, albeit with longer processing times, and allowed us producing cattle distribution maps for the entire Guadeloupe archipelago at a spatial resolution of 225 m using both algorithms. The approach developed holds potential for application to other small territories, including other islands in the Caribbean.

bioinformatics↗

bioRxiv2025

First detection of Crimean Congo Hemorrhagic Fever antibodies in cattle and wild fauna of southern continental France: investigation of explicative factors

Crimean-Congo Haemorrhagic Fever (CCHF) is a tick-borne zoonosis with significant public health implications due to its expanding geographic distribution and potential for severe outcomes in humans. This study represents the first serological survey conducted in mainland France to detect antibodies against the Crimean-Congo Haemorrhagic Fever Virus (CCHFV) in domestic and wild fauna, providing critical insights into the viruss circulation. We analyzed 8,609 cattle sera and 2,182 wildlife sera collected across the French Mediterranean region from 2008 to 2022, using enzyme-linked immunosorbent assays (ELISA) and pseudo-plaque reduction neutralization tests (PPRNT) for antibody detection and confirmation. Seropositivity was detected in both cattle (2.04%) and wildlife (2.25%), with higher rates observed in specific regions such as Pyrenees-Orientales and Hautes-Pyrenees. These findings reveal spatial clusters of CCHFV circulation and suggest the existence of enzootic transmission cycles involving local tick vectors and animal hosts. Our multivariate analysis identified key factors influencing seropositivity, including animal age, habitat characteristics, and potential wildlife interactions. The presence of natural open habitats and coniferous forests was significantly associated with higher seropositivity in cattle, while sex and geographical variability played a role in wildlife seroprevalence. These findings highlight the importance of environmental and anthropogenic factors in shaping the dynamics of CCHFV transmission. This study demonstrates that CCHFV is actively circulating in parts of mainland France, emphasizing the need for enhanced surveillance and integrated approaches to monitor zoonotic pathogens. It also raises questions about the role of additional tick vectors, such as Hyalomma lusitanicum, in the transmission cycle. These results contribute to a better understanding of CCHF epidemiology and offer valuable guidance for public health strategies to mitigate the risks associated with this emerging disease. Author SummaryCrimean-Congo Haemorrhagic Fever (CCHF) is a severe disease spread by ticks that affects humans and animals. Although the disease is largely distributed in parts of Europe, Africa, and Asia, its presence in France has been uncertain. My study investigated whether the virus causing this disease is circulating in southern mainland France by testing blood samples from domestic animals, like cattle, and wild animals, such as deer and wild boars, for signs of previous infection. I found evidence of the virus in several regions, particularly in the Pyrenees-Orientales, Hautes-Pyrenees and Alpes-maritimes, suggesting that the virus is indeed circulating among animals and ticks in some parts of mainland France. By studying where infected animals were found and considering factors such as age, habitat, and environmental conditions, I identified that older animals seem to have been more often exposed to the virus, as well as animals frequenting open environments favorable to ticks. These findings are important because they show that the disease could potentially spread to new areas and affect human populations. My work highlights the need for ongoing monitoring of ticks and animals for CCHFV epidemiological surveillance and the protection of public health.

ecology↗

bioRxiv2023

Longitudinal Survey of Astrovirus infection in different bat species in Zimbabwe: Evidence of high genetic Astrovirus diversity

Astroviruses (AstVs) have been discovered in over 80 animal species including diverse bat species and avian species. A study on Astrovirus circulation and diversity in different insectivorous and frugivorous chiropteran species roosting in trees, caves and building basements was carried out at 11 different sites across Zimbabwe. Pooled and individual faecal sampling methods were used for this study, with collection dates ranging from June 2016 to July 2021. In two sites, Magweto and Chirundu, sampling was carried out at monthly intervals from August 2020 to July 2021. Astroviruses and bat mitochondrial genes were amplified using pan-AstVs and CytB /12S RNA PCR systems respectively. Phylogenetic analysis of the RdRp Astrovirus sequences revealed a high genetic diversity of astroviruses. All the bat astroviruses tested in this study clustered with the Mamastrovirus genus. Two distinct groups of amplified sequences were identified. One group was comprised of sequences isolated from Hipposideros, Rhinolophus and Eidolon helvum spp. clustered with Human Astrovirus strains: HuAstV types1-6, HuAstV-MLB1-3 and HuAstV-VA-1. The second group comprising the majority of the sequences clustered with different strains of Bat AstVs. Results from the longitudinal study at Magweto and Chirundu showed an overall AstV prevalence of 13.7% and 10.4% respectively. Peaks of AstV infection at Chirundu coincided with the period when juveniles are 4-6 months old. By combining data from our previous work on Coronaviruses, we also anaylzed co-infection of bats with Coronaviruses and Astroviruses at Magweto and Chirundu sites for which the prevalence of co-infection was 2.6% and 3.5% respectively.

molecular biology↗