Pascal Delaunay

La fréquence de la schistosomiase importée par les migrants mineurs non accompagnés (MNA) est mal connue en France. Nous avons recherché, entre décembre 2023 et février 2024, une schistosomiase chez les MNA en plus du dépistage de la tuberculose dans notre Centre de lutte antituberculeuse des Alpes-Maritimes. Un dépistage sérologique (Western Blot) a été proposé à tous les MNA originaires d’Afrique subsaharienne (ASS). En cas de positivité, un examen parasitologique des urines et des selles a été proposé. Au cours de ces trois mois, 187 MNA d’ASS ont été dépistés. La sérologie était positive pour 116 (62 %) d’entre eux. L’âge médian était de 16 ans et le sex-ratio (H/F) de 6,9. Des examens parasitologiques ont pu être réalisés pour 58 (50 %) des 116 MNA ayant une sérologie positive. Des œufs de schistosome ont été trouvés chez 24 d’entre eux. Il y avait des œufs de Schistosoma mansoni dans les selles de 14 MNA, des œufs de S. haematobium dans les urines de 9 MNA et la présence à la fois de S. mansoni et de S. haematobium chez 1 MNA. Cinq MNA présentaient une hématurie (avec S. haematobium) au moment de l’étude. La prévalence de la schistosomiase était d’au moins 12,5 % (24/187). La schistosomiase est fréquente chez les MNA et les formes asymptomatiques sont les plus nombreuses.

The prevalence of asymptomatic leishmaniasis in dogs and their owners in the main endemic areas of France has not been studied to date. The objective of this study was to quantify asymptomatic Leishmania infantum infection in southeast France in healthy people and their dogs using molecular and serological screening techniques. We examined the presence of parasitic DNA using specific PCR targeting kinetoplast DNA (kDNA) and specific antibodies by serology (ELISA for dogs and Western blot for humans) among immunocompetent residents and their dogs in the Alpes-Maritimes. Results from 343 humans and 607 dogs were included. 46.9% (n = 161/343) of humans and 18.3% (n = 111/607) of dogs were PCR positive; 40.2% of humans (n = 138/343) and 9.9% of dogs (n = 60/607) were serology positive. Altogether, 66.2% of humans (n = 227) and 25.7% of dogs (n = 156) had positive serologies and/or positive PCR test results. Short-haired dogs were more frequently infected (71.8%, n = 112) than long-haired dogs (12.2%, n = 19) (p = 0.043). Dogs seemed to be more susceptible to asymptomatic infection according to their breed types (higher infection rates in scenthounds, gun dogs and herding dogs) (p = 0.04). The highest proportion of dogs and human asymptomatic infections was found in the Vence Region, corresponding to 28.2% (n = 20/71) of dogs and 70.5% (n = 31/44) of humans (4.5/100,000 people). In conclusion, the percentage of infections in asymptomatic humans is higher than in asymptomatic dogs in the studied endemic area. It is questionable whether asymptomatic infection in humans constitutes a risk factor for dogs.

Bed bug has become a major public health pest worldwide. Infestation may result in numerous negative health effects. Homeless shelters are one of the most habitats that can be infested with bed bugs, a few studies have focused on bed bug infestations in these settings. We conducted a survey of infestations of bed bugs in a homeless shelter in southern France, using an innovative seven-level scale (0–6) to assess the degree of infestation, MALDI TOF-MS to identify bed bugs, and a biomolecular tool to detect bacteria. Bed bug infestations were documented in 13% (9/68) of investigated rooms. A total of 184 bed bugs were collected and morphologically identified as Cimex lectularius. MALDI TOF–MS analysis allowed us to obtain high-quality MS spectra for all 184 specimens, to correctly identify all specimens, and included 178/184 (97%) Log Score Values higher than 1.8. Among the bacteria tested, Wolbachia sp. DNA was found in 149/184 (81%) of the bed bugs, and one sample was positive for Coxiella burnetii, the agent of Q fever. Our study is the first of its kind that offers new perspectives for increasing public awareness of the conditions in homeless shelters.

A simple method for accurately identifyingGlossina sppin the field is a challenge to sustain the future elimination of Human African Trypanosomiasis (HAT) as a public health scourge, as well as for the sustainable management of African Animal Trypanosomiasis (AAT). Current methods for Glossina species identification heavily rely on a few well-trained experts. Methodologies that rely on molecular methodologies like DNA barcoding or mass spectrometry protein profiling (MALDI TOFF) haven’t been thoroughly investigated forGlossinasp. Nevertheless, because they are destructive, costly, time-consuming, and expensive in infrastructure and materials, they might not be well adapted for the survey of arthropod vectors involved in the transmission of pathogens responsible for Neglected Tropical Diseases, like HAT. This study demonstrates a new type of methodology to classifyGlossinaspecies. In conjunction with a deep learning architecture, a database of Wing Interference Patterns (WIPs) representative of theGlossinaspecies involved in the transmission of HAT and AAT was used. This database has 1766 pictures representing 23 Glossinaspecies. This cost-effective methodology, which requires mounting wings on slides and using a commercially available microscope, demonstrates that WIPs are an excellent medium to automatically recognize Glossina species with very high accuracy.

Bufavirus (BuV) and human parvovirus 4 (PARV4) belong to the Parvoviridae family. We assessed BuV and PARV4 DNA presence by real-time PCR analysis in stool, blood and respiratory samples collected in patients from Marseille and Nice, two large cities in the South-East of France. Bu-V DNA was detected in diarrheic stool samples from 92 patients (3.6% of 2583 patients), particularly men and adults, and patients from the nephrology and the infectious disease departments. Among the patients with a BuV-positive stool sample and for whom at least one blood sample was available (n = 30 patients), BuV DNA was detected also in 3 blood samples. In contrast, BuV DNA was not detected in any of the respiratory samples from 23 patients with BuV-positive stool. BuV detection rate was comparable in stool samples from patients with and without diarrhea. We did not detect PARV4 DNA in any of the stool specimens (n = 2583 patients). Our results suggest that PARV4 fecal–oral transmission is rare or non-existent in the South-East of France while BuV circulates with a relatively high rate in this area.

The bed bugs (Cimex lectularius and C. hemipterus) have undergone a significant resurgence worldwide since the 1990s. A compilation of findings from a database, including 2650 scientific publications from seven major medical databases, allowed us to document main evolutionary events, from fossil evidence, dating from 11,000 years ago, until the present that has led to the current worldwide expansion of Cimicid species. We present the hypotheses on the possible dispersion pathways of bed bugs in light of the major historical and evolutionary events. A detailed classification of the Cimicidae family and finally, an illustrative map displaying the current distribution of known Cimex species in each geographical ecozone of Asia, Europe, Africa, the Americas, and Australia are presented.

Background Expert visualization of Sarcoptes scabiei remains essential for diagnosing human scabies but access to experts can be difficult. PCR is a very specific tool for the detection and confirmation of Sarcoptes scabiei but this test has a poor sensitivity because of the requirement of previous expertise when collecting appropriate samples to gain a positive result. Objective Evaluate PCR as a diagnostic method for scabies using non expert‐dependent standardized sampling. Methods The dry swab was systematically rubbed across the front of both wrists, the eight interdigital spaces and on any suspected scabies lesions in all patients referred for scabies. A new PCR‐based diagnostic test was run on the samples. All patients underwent clinical and dermoscopic examination. Scabies diagnosis was confirmed when dermoscopic examination was positive or the patient had typical clinical signs of scabies. Results Of 183 suspected scabies patients, 164 patients were sampled, 87 had confirmed scabies (dermoscopy positive n=87, typical clinical sign n=1) and 77 did not. Of the 87 patients with proved scabies, 33 patients had positive scabies PCR resulting in a 37.9% (95% CI=28.4‐48.4%) sensitivity and a 61.7%. (95% CI=52.4‐72.7%) Negative Predictive Value. None of the 77 patients ruled out for scabies had a positive PCR result. Conclusion This method is non‐traumatic, repeatable, non‐expert‐dependent. It shows sensitivity similar to previous studies involving expert skin scraping. However, this method facilitates the multiplication of sampling which increased sensitivity for cluster scabies diagnosis. This method may be suitable as a first line diagnosis tool for suspicion of large cluster scabies outbreak.