Pigs are suspected to act as a reservoir for Trypanosoma brucei gambiense and may therefore contribute to the re-emergence of human African trypanosomiasis (HAT), despite ongoing efforts to eliminate transmission. To clarify the role of this species in HAT epidemiology and to better understand the dynamics of T. b. gambiense infection in blood, we experimentally infected pigs with this parasite. In this study, we compared nine infected pigs with eight control pigs over a period of more than ten months using parasitological, molecular, and serological methods. The results showed that each diagnostic method has limitations, in terms of sensitivity to detect the presence of T. b. gambiense, and specificity to differentiate infection caused by T. b. gambiense from infection caused by T. b. brucei, responsible for animal African trypanosomosis. Nevertheless, the overall analysis showed that pigs can remain infected with T. b. gambiense for at least ten months. Hence, pigs should be considered a potential long-term reservoir of T. b. gambiense that could compromise the sustainability of the current elimination process. As a result, there is a need to pursue investigations on this topic, considering possible co-infections with T. b. brucei. In the meantime, adapted measures should be envisaged to limit contact between pigs and tsetse flies and/or to clear potential pig infections with T. b. gambiense by curative treatment.
Corsica is a mountainous French island in the northwestern Mediterranean Sea characterized by a wide diversity of natural environments where many interactions between humans, domestic animals and wild fauna occur. Gastrointestinal parasitism is a major concern for livestock productivity. Among these parasites, Cryptosporidium spp. and Giardia duodenalis are zoonotic, cosmopolitan protozoa frequently implicated in diarrheal diseases in both young animals and children. Despite an apparent favourable epidemiological context, gastrointestinal parasites remain understudied in Corsica. Between May 2023 and May 2024, 281 faecal samples were collected: 261 pooled ruminant samples (five animals per pool) from goats ( n = 121), sheep ( n = 117), and cattle ( n = 23) across 159 farms and 20 individual samples from horses ( n = 14) and pigs ( n = 6). Coproscopic analyses detected at least one gastrointestinal parasite in 93% of all samples. Strongyle eggs (91%) and coccidian oocysts (72%) were most prevalent in ruminants. Molecular analyses (including real-time PCR and genotyping) identified Cryptosporidium spp. in 11 samples (3.9%): nine goats, one sheep, and one pig. Three zoonotic species were confirmed: Cryptosporidium parvum (genotype family IId) in five goat samples and one sheep sample, C. ubiquitum in one goat sample, and C. scrofarum in one pig sample (first report of this species in France). Giardia duodenalis assemblage E was detected in a goat herd. This study documents widespread gastrointestinal parasitism in Corsican livestock. While no human cases of giardiasis or cryptosporidiosis have officially been reported in Corsica, this first detection of zoonotic species in livestock highlights potential public health risks and supports the need for evidence-based prevention strategies for humans and animals.
Human lice are hematophagous ectoparasites of worldwide distribution and public health concern. Despite their medical importance, the genetic diversity of these ectoparasites remains poorly documented, with only one prior study conducted in France. In this study, we investigated the distribution and genetic diversity of human louse populations collected from patients referred to Avicenne Hospital, northern Paris, between 2019 and 2023. A total of 209 specimens, one per patient, were examined: 186 head lice ( Pediculus humanus capitis ), 11 body lice ( Pediculus h. corporis ), and 12 pubic lice ( Pthirus pubis ). Head lice predominated in women (82.3%), whereas body and pubic lice were more frequent in men (81.8% and 83.3%, respectively). Among head lice patients, 75.8% were children under 18 years, while all body lice patients and 83.3% of pubic lice patients were adults. Two infants with pubic lice were diagnosed, presumably infected by their parents, highlighting transmission risk among family members. Four pubic lice cases involved men who have sex with men. Phylogenetic analysis of cytochrome oxidase I ( COI ) sequences using the maximum likelihood method and comparison to GenBank sequences from multiple regions revealed genetic heterogeneity, with sequences clustering into three monophyletic clades (A, B and C). Clade C is reported for the first time in France. Body louse sequences clustered exclusively within clade A. Together with our previous work, this study represents the first epidemiological investigation of human lice infestation in a general French population, contrasting with earlier reports restricted to schoolchildren. Our findings also improve our understanding of human louse genetic diversity with implications for control strategies.
Genotyping of cystic echinococcosis (CE) specimens enables the identification of predominant species and genotypes, yielding critical insights into disease epidemiology. Species identification is essential for the development of effective prevention and control strategies. In this context, we assessed the molecular diversity of E. granulosus sensu lato among surgically confirmed human CE cases recruited from Algerian referral hospitals. Hydatid cysts were collected from 31 patients undergoing surgery for pulmonary and/or hepatic CE in Algeria between 2022 and 2024. Hydatid fluid, cyst wall, and laminated-layer preparations were used for DNA extraction. End-point PCR coupled with Sanger sequencing, targeting the mitochondrial 12S- rrnS , nad5 , and nad2 markers, was performed for species identification and genotyping, with real-time PCR (qPCR) performed in parallel. End-point PCR was successful in 29 cases (93.5%), while qPCR detected DNA of Echinococcus spp. in 30 cases (96.8%). The additional qPCR-positive sample showed late amplification but could not be assigned to a genotype because no sequence was obtained. Among the 29 molecularly characterized samples, E. granulosus sensu stricto genotype G1 was predominant and was identified in 27 samples (93.1%). One isolate was identified as E. granulosus sensu stricto genotype G3, and one as E. canadensis G6/G7. Genotype G1 and G3 cases were distributed in northern and central Algeria, while the G6/G7 isolate was detected in a patient from Tindouf, southern Algeria. These results demonstrate the predominance of E. granulosus sensu stricto genotype G1 among the molecularly characterized human cystic echinococcosis cases in this series.
Following the detection of Brachylaima spp., which are potentially pathogenic for domestic animals and humans, in Cornu aspersum and Cepaea nemoralis at a rural site in France, we investigated trematode distribution among sympatric gastropod species to assess their role in the parasite life cycle. Eight species were investigated ( Cepaea nemoralis , Cernuella neglecta, Clausilia bidentata , Cochlicella acuta, Cornu aspersum , Lauria cylindracea, Pomatias elegans , and Theba pisana ). Four species were parasitised by trematodes: C. aspersum (prevalence 56%), C. nemoralis (10%), and T. pisana (2%) as second intermediate hosts of Brachylaima spp., and C. neglecta (6%) as new first intermediate host of Pseudoleucochloridium sp. Moreover, we observed for the first time shell-encapsulation of trematodes in a non-helicid species ( C. neglecta ) and nematodes in a non-stylommatophoran species ( P. elegans ), suggesting more general anti-parasite defence than previously thought among land snails. Our current and previous results, including molecular data (28S rDNA, COI mtDNA), suggest the occurrence of four Brachylaima species at the site: Brachylaima mesostoma and three unidentified species. Cornu aspersum is the only identified first intermediate host for B. mesostoma and one of the unidentified trematode species also found at a metacercarial stage in C. aspersum and C. nemoralis . Another unidentified species recorded in C. aspersum and C. nemoralis , characterised by small orange metacercariae, may be a new species. The sole metacercaria found in T. pisana may also belong to an undescribed species.
