Risk Of Human Infection Research Articles

Genetic Characterization of Japanese Encephalitis Virus Isolates Circulating in Mosquitoes from Pig and Sheep Farms in Shanghai, China

Japanese encephalitis virus (JEV) is regarded as an emerging and reemerging pathogen that is a primary cause of viral encephalitis in humans. However, there is a scarcity of research on the prevalence of JEV genotypes across the different mosquito species in Shanghai. In this study, the diversity of mosquito species and prevalence of JEV in pig and sheep farms in Shanghai were surveyed in 2022. A total of 24,073 mosquitoes, belonging to four genera and seven species, were collected from pig and sheep enclosures in the Chongming, Jiading, Pudong, Fengxian, and Jinshan Districts of Shanghai. Culex tritaeniorhynchus was identified as the predominant species (87.09%, 20,965/24,073) with the highest JEV detection rate. Six strains of JEV were isolated in this study, and genetic analysis revealed that five strains (SH22-M5, SH22-M9, SH22-M14, SH22-M41, and SH22-M52) belonged to genotype I (GI), while one strain (SH22-M1) was classified as genotype III (GIII). The sequence homology was highest between SH22-M9 and SD-1 (99.87%) and between SH22-M14 and SD12 (99.53%). SH22-M5, SH22-M41, and SH22-M52 shared the highest sequence homology with the HEN07011 strain (99.73–99.93%). SH22-M1 was most closely related to SH18, with a sequence homology of 99.8%. Additionally, for the first time, the GI JEV strain was isolated from mosquitoes in sheep sties in this study. The findings highlight the necessity of enhancing the surveillance of JEV in pigs and other livestock farms, including sheep, as well as monitoring the mosquitoes present in these environments. It is recommended that livestock farming areas be kept separate from human habitation to reduce the risk of JEV infections in humans.

Occurrence of Leishmania spp. in phlebotomine sand flies and dogs in Guelma region, North-eastern Algeria

Leishmania spp. are sand fly-borne parasitic protozoa of worldwide distribution that may severely affect the health and welfare of dogs as well as of other mammalian species, including humans. Algeria is among the most affected countries, counting several cases of Leishmania infantum infection in humans and dogs. Here, we assessed the occurrence of Leishmania species in both phlebotomine sand fly and dogs in the Guelma region, Northeast of Algeria. Sand flies were collected from July to September 2022, followed by a survey of canine leishmaniasis (CanL) from September 2023 to February 2024. Additionally, to understand the risk of human infection a retrospective data on cases of leishmaniasis recorded in the region from 2012 to 2023 were reported. Sand fly specimens and canine blood samples were tested by quantitative PCR (qPCR) for Leishmania spp., while dog serum samples were processed for anti-L. infantum antibodies detection by immunofluorescent antibody test (IFAT). Of the 1478 sand flies (n = 318 females; n = 1160 males), seven species were identified (i.e., Phlebotomus papatasi, Ph. perfiliewi, Ph. sergenti, Ph. perniciosus, Ph. longicuspis, Ph. ariasi, and Sergentomyia minuta). Leishmania spp. was detected in Ph. perniciosus, Ph. perfiliewi, Ph. papatasi, and Ph. sergenti (i.e., 3.7 %; n = 10). The overall seroprevalence rate was 58.2 %, with 1.6 % of dog blood samples positive for L. infantum at molecular screening. Multivariate analysis of the different risk factors revealed that CanL seropositivity was strongly related to dog age (> 1 year) (OR = 8.35, 95 % CI: 3.43–23.93), the autumn season (OR = 2.95, 95 % CI: 1.33–8.62), and lack of insecticide application (OR = 6.69, 95 % CI: 2.61–22.02). A total of 71 human cases of cutaneous (CL) and visceral (VL) leishmaniasis were recorded. Data presented reveal the occurrence of CanL in Guelma region, advocating for control program measures to be implemented in this part of Algeria.

Cost-Effectiveness of Extending Human Papillomavirus Vaccination to Population Subgroups Older Than 26 Years Who Are at Higher Risk for Human Papillomavirus Infection in the United States.

In June 2019, the U.S. Advisory Committee on Immunization Practices recommended shared clinical decision making regarding potential human papillomavirus (HPV) vaccination of men and women aged 27 to 45 years ("mid-adults"). To examine the incremental cost-effectiveness ratios (ICERs) and number needed to vaccinate (NNV) to prevent 1 HPV-related cancer case of expanding HPV vaccination to subgroups of mid-adults at increased risk for HPV-related diseases in the United States. Individual-based transmission dynamic modeling of HPV transmission and associated diseases using HPV-ADVISE (Agent-based Dynamic model for VaccInation and Screening Evaluation). Published data. All U.S. mid-adults and higher-risk subgroups within this population. 100 years. Health care sector. Expanding 9-valent HPV vaccination to mid-adults and higher-risk subgroups. ICERs and NNVs. Expanding 9-valent HPV vaccination to all mid-adults, those with more lifetime partners, and those who have just separated was projected to cost an additional $2 005 000, $763 000, and $1 164 000 per quality-adjusted life-year (QALY) gained, respectively. The NNVs to prevent 1 additional HPV-related cancer case were 7670, 3190, and 5150, respectively, compared with 223 for vaccination of persons aged 9 to 26 years (vs. no vaccination). The mid-adult strategy with the lowest ICER and NNV was vaccinating infrequently screened mid-adult women who have just separated and have a higher number of lifetime sex partners (ICER, $86 000 per QALY gained; NNV, 470). Uncertainty about rate of new sex partners and natural history of HPV among mid-adults. Vaccination of mid-adults against HPV is substantially less cost-effective and produces higher NNVs than vaccination of persons younger than 26 years under all scenarios investigated. However, cost-effectiveness and NNV are projected to improve when higher-risk mid-adult subgroups are vaccinated, such as mid-adults with more sex partners and who have recently separated, and women who are underscreened. Centers for Disease Control and Prevention.

Feline sporotrichosis: occurrence in the Metropolitan Region of the municipality of Recife and anatomical distribution of lesions on cats’ body

Sporotrichosis is a fungal infection of worldwide importance caused by a saprophyte fungus of the genus Sporothrix. The objective of this study was to report the occurrence of feline sporotrichosis in the Metropolitan Region of the city of Recife and the anatomical distribution of lesions on the bodies of cats. Stray cats (n=100) with suggestive sporotrichosis lesions were examined. Material from the lesion was collected from all patients using an imprint and/or sterile swab for cytology. The material was placed on a glass slide and stained using rapid panoptic staining. Data on the localization of each skin lesion were recorded, and cigar-shaped yeast structures were searched at the microscopical examination. A heat map graphically represented the anatomical distribution of each lesion. In 70% (70/100) of samples were visualized fungal structure compatible with Sporothrix spp. There was a predominance of positive males (?2=6.691; p=0.0097). Skin lesions related to Sporothrix spp. infections were unevenly distributed throughout the animal's body. Based on the interpolation of data, the chance for detecting lesions was higher on the nose, anterior paw, and ears than on other body sites (H=40.0043; p=0.0000). Because of the high positivity in these cats, measures of health vigilance are imperative to reduce the risk of animal and human infection.

Source attribution of Listeria monocytogenes in the Netherlands

The aim of this study was to determine the relative contributions of various potential food sources of human listeriosis and to identify source-specific risk factors, at exposure level, for human Listeria monocytogenes (Lm) infection. To achieve this, available Lm isolates from human cases (n = 756) and food/animal sources (n = 950) from national surveillance systems in the Netherlands (2010−2020) were whole genome sequenced. Additionally, questionnaire-based exposure data for human cases was collected. Source attribution analysis was performed using a Random Forest model based on core-genome multilocus sequence typing (cgMLST). Risk factors for human Lm infection of cattle, chicken and seafood origin were determined using beta regression analysis on the cgMLST-based attribution estimates. Results indicated that the 756 human Lm isolates were mainly attributed to cattle (62.3 %), chicken (19.4 %), and seafood (16.9 %). Specifically, fresh meat (86.2 %), including fresh bovine meat (43.7 %) and fresh chicken meat (39.3 %), accounted for most cases. These attributions stemmed from Lm contamination of either the food products or their production environments. Consumption of steak tartare and smoked salmon was associated with an increased risk of human Lm infections attributed to cattle and seafood, respectively, while no specific risk factors for chicken-borne listeriosis were identified. This study indicated that Lm isolates of cattle origin, particularly those from fresh bovine meat and associated production environments, are estimated to be the primary cause of human listeriosis in the Netherlands. This aligns with several other European source attribution studies on Lm. Moreover, the identified risk factors for human Lm infection from cattle (i.e. steak tartare) and seafood (i.e. smoked salmon) clearly indicated their attributable sources. This joint analysis of core genome and epidemiological data provided novel insights into the origins and transmission pathways of human listeriosis.

Presence of Echinococcus eggs in the environment and food: a review of current data and future prospects.

Cystic and alveolar echinococcosis are considered the second and third most significant foodborne parasitic diseases worldwide. The microscopic eggs excreted in the feces of the definitive host are the only source of contamination for intermediate and dead-end hosts, including humans. However, estimating the respective contribution of the environment, fomites, animals or food in the transmission of Echinococcus eggs is still challenging. Echinococcus granulosus and E. multilocularis seem to have a similar survival capacity regarding temperature under laboratory conditions. In addition, field experiments have reported that the eggs can survive several weeks to years outdoors, with confirmation of the relative susceptibility of Echinococcus eggs to desiccation. Bad weather (such as rain and wind), invertebrates and birds help scatter Echinococcus eggs in the environment and may thus impact human exposure. Contamination of food and the environment by taeniid eggs has been the subject of renewed interest in the past decade. Various matrices from endemic regions have been found to be contaminated by Echinococcus eggs. These include water, soil, vegetables and berries, with heterogeneous rates highlighting the need to acquire more robust data so as to obtain an accurate assessment of the risk of human infection. In this context, it is essential to use efficient methods of detection and to develop methods for evaluating the viability of eggs in the environment and food.

First Report of a Fatal Septicemia Case Caused by Vibrio metoecus: A Comprehensive Functional and Genomic Study

Abstract Background In recent years, we have witnessed an unprecedented increase in the incidence of vibriosis due to global warming. Vibrio metoecus is a recently described Vibrio cholerae-like species that has not been associated with septicemia death in humans. During follow-up of human vibriosis, we received a blood isolate from a patient with secondary septicemia who died a few hours after admission. Methods Phenotypic and genotypic methods failed to identify the isolate, which could only be identified by average nucleotide identity after genome sequencing. The isolate was subjected to in vitro and ex vivo assays, complemented by comparative genomics focused on the identification of unique genetic traits. Strains and genomes from the same and related species (V. cholerae and Vibrio mimicus) were used for analyses. Results The isolate was the only one able to resist and multiply in human serum. Its genome contained virulence genes shared with V. mimicus and/or V. cholerae, with those associated with sialic acid degradation within pathogenicity island 2 standing out. However, it also presented a unique gene cluster, flanked by a transposase gene, putatively related to surface polysaccharide pseudosialyzation. Conclusions We document the first case of death caused by septicemia due to V. metoecus and propose that the acquisition of surface pseudosialyzation genes explains the ability of certain isolates of this species to survive in blood. Our discovery underscores the urgent need to monitor and study newly emerging pathogenic species, as climate change may be facilitating their spread and increasing the risk of serious infections in humans.

Designing of a Novel Aerolysin-based Multiepitope Vaccine against Aeromonas hydrophila Isolated from Osphronemus goramy Using Reverse Vaccinology: an in Silico Approaches

Graphical Abstract Highlight Research The study aims to develop a multi-epitope vaccine (MEV) against A. hydrophila by targeting the aerolysin toxin, a key virulence factor responsible for infections in fish and humans. Computational methods identified and optimized B-cell and T-cell epitopes, focusing on their ability to trigger immune responses without causing toxicity or allergenicity. In silico simulations demonstrated that the MEV has a strong binding affinity to immune receptors like TLR-4, MHC-I, and MHC-II, indicating its potential to induce robust cellular and humoral immunity. Structural analysis of the MEV showed a stable 3D conformation, with most residues in favorable regions, ensuring stability during immune activation. The MEV could enhance disease control in aquaculture and reduce human infection risks, offering a promising solution to address antibiotic resistance and the absence of effective vaccines. Abstract Aeromonas hydrophila, gram-negative, is a major pathogen responsible for various diseases in mammals, reptiles, amphibia, and vertebrates, including fish and humans. Targeting the specific toxin aerolysin in A. hydrophila is crucial to address antibiotic resistance and the lack of adequate and protective vaccines against this intracellular pathogen. This study aimed to identify a multi-epitope vaccination (MEV) candidate targeting A. hydrophila aerolysin toxin to combat the disease effectively. Standard biochemical characterization methods and sequencing of the 16S rRNA, rpoB, and aerA genes identified the isolate AHSA1 as A. hydrophila. Subsequently, we identified B and T cell epitopes on the aerolysin protein and separately predicted MHC-I and MHC-II epitopes. The epitopes are then evaluated for toxicity, antigenicity, allergenicity, and solubility. The vaccine design integrated multi-epitope-based constructs, utilizing specialized linkers (GPGPG) and EAAAK linkers to connect epitope peptides with adjuvants in the cholera toxin B component, thereby enhancing immunogenicity. Ramachandran plots showed that 85.25% of the residues were located in the most favorable regions, which was followed by the generously allowed zone (1.30%), the additional allowed regions (10.80%), and the forbidden regions (2.65%), thus confirming the feasibility of the modeled vaccine design. Based on docking simulations, MEV had the highest binding and interaction energies with TLR-4, TLR-9, MHC-I, and MHC-II (-1081.4, -723.2, 866.2, -9043.3 kcal/mol). Based on computational modelling, we expect the Aerolysin MEV candidate design to activate diverse immune mechanisms, stimulate robust responses against A. hydrophila, and maintain safety. The significant solubility, absence of toxicity or allergic response, and minimal side effects in animal testing all contribute to the potential clinical utility of this vaccine candidate.

Safety and immunogenicity of a SARS-CoV-2 mRNA vaccine (SYS6006) in minks, cats, blue foxes, and raccoon dogs.

Minks, cats, and some other species of carnivores are susceptible of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and have a high risk of transmitting SARS-CoV-2 to humans. The development of animal vaccines can be an effective measure to protect animals against SARS-CoV-2 and reduce the potential risk of human infection. We previously developed a messenger ribonucleic acid (mRNA) vaccine SYS6006 that has been proven to be an efficient coronavirus disease 2019 (COVID-19) vaccine widely used in humans. Here, we further evaluated the safety and immunogenicity of SYS6006 as an animal COVID-19 vaccine candidate for SARS-CoV-2 susceptible animals or wild animals. SYS6006 was safe and immunogenic in mice and completely protected mice against mouse-adapted SARS-CoV-2 infection in the upper and lower respiratory tracts. SYS6006 was able to induce neutralizing antibodies against the SARS-CoV-2 wild-type, Delta, and Omicron BA.2 strain on day 7 after prime immunization, and two doses of immunization could enhance the neutralizing antibody responses and produce long-lasting potent antibodies for more than 8 months in minks and cats, blue foxes, and raccoon dogs, while all immunized animals had no abnormal clinical signs during immunization. These results provided here warrant further development of this safe and efficacious mRNA vaccine platform against animal COVID-19.

Disentangling the influence of reservoir abundance and pathogen shedding on zoonotic spillover of the Leptospira agent in urban informal settlements.

Rats are major reservoirs for pathogenic Leptospira, the bacteria causing leptospirosis, particularly in urban informal settlements. However, the impact of variation in rat abundance and pathogen shedding rates on spillover transmission to humans remains unclear. This study aimed to investigate how spatial variation in reservoir abundance and pathogen pressure affect Leptospira spillover transmission to humans in a Brazilian urban informal settlement. A longitudinal eco-epidemiological study was conducted from 2013 to 2014 to characterize the spatial distribution of rat abundance and Leptospira shedding rates in rats and determine the association with human infection risk in a cohort of 2,206 community residents. Tracking plates and live-trapping were used to measure rat abundance and quantify rat shedding status and load. In parallel, four sequential biannual serosurveys were used to identify human Leptospira infections. To evaluate the role of shedding on human risk, we built three statistical models for: (1) the relative abundance of rats, (2) the shedding rate by individual rats, and (3) human Leptospira infection, in which "total shedding", obtained by multiplying the predictions from those two models, was used as a risk factor. We found that Leptospira shedding was associated with older and sexually mature rats and varied spatially and temporally-higher at valley bottoms and with seasonal rainfall (December to March). The point estimate for "total shedding" by rat populations was positive, i.e., Leptospira infection risk increased with total shedding, but the association was not significant [odds ratio (OR) = 1.1; 95% confidence interval (CI): 0.9, 1.4]. This positive trend was mainly driven by rat abundance, rather than individual rat shedding (OR = 1.8; 95% CI: 0.6, 5.4 vs. OR = 1.0; 95% CI: 0.7, 1.4]. Infection risk was higher in areas with more vegetative land cover (OR = 2.4; 95% CI: 1.2, 4.8), and when floodwater entered the house (OR = 2.4; 95% CI: 1.6, 3.4). Our findings indicate that environmental and hydrological factors play a more significant role in Leptospira spillover than rat associated factors. Furthermore, we developed a novel approach combining several models to elucidate complex links between animal reservoir abundance, pathogen shedding and environmental factors on zoonotic spillover in humans that can be extended to other environmentally transmitted diseases.

Dirofilaria immitis and Dirofilaria repens: Investigating the Prevalence of Zoonotic Parasites in Dogs and Humans in a Hyperenzootic Area.

The mosquito-borne zoonotic nematode parasites Dirofilaria immitis and Dirofilaria repens primarily affect dogs. In recent years, their distribution has expanded due to various factors influencing vector-borne pathogens. This study aimed to investigate the comparative prevalence of infection in dogs and humans within a hyperenzootic region of Europe, and to estimate the proportional relationship between infection prevalence in dogs and humans, within the concept of "One Health". To this end, 604 blood samples from dogs and 625 serum samples from humans living in the Thrace region of northeastern Greece were collected. The dog samples were examined for Dirofilaria spp. microfilariae using Kott's test and for D. immitis antigen using a commercial serological test. The human sera were analyzed for both parasites by Western blot. The overall prevalence of infection in dogs was 177 (29.3%), with 173 (28.6%) testing positive for D. immitis and 7 (1.2%) for D. repens, including 6 (1%) cases of mixed infection. Specific IgG antibodies were detected in 42 (6.7%) human samples, with 24 (3.8%) positive for D. immitis and 18 (2.9%) for D. repens. The infection proportion in humans was 23.4% of the corresponding canine infections, indicating a high risk of human infection in this hyperenzootic region.

Molecular Screening and Genetic Identification of Anaplasma platys in Brown Dog Tick (Rhipicephalus sanguineus s. l.) Infested on Stray Dogs in Taiwan.

Anaplasma platys is a tick-borne zoonotic pathogen of canines. In this study, the presence of A. platys was screened for in brown dog ticks (Rhipicephalus sanguineus s. l.) infesting stray dogs in Taiwan to determine overall prevalence. This study represents the first instance of genetic identification of A. platys in brown dog ticks in Taiwan. In total, we examined 324 brown dog ticks for A. platys infection by nested polymerase chain reaction assay targeting the 16S ribosomal RNA gene. The general prevalence of A. platys infection was 3.1%, with 3.6%, 4.0%, and 2.1% in nymph, female, and male ticks, respectively. Monthly prevalence of infection was observed from May to September. Genetic relatedness was determined by comparing the sequences of the 16S rRNA gene obtained from six Taiwan strains and seventeen other strains, representing six genospecies of Anaplasma spp. and three outgroups (Ehrlichia canis, Rickettsia rickettsia, and Escherichia coli). All Taiwan specimens were shown to genetically belong to the A. platys group, and could be clearly discriminated from other Anaplasma spp. Genetic similarities revealed a 100% identity match with various A. platys documented in GenBank. This study highlights the epidemiological importance of geographical transmission of A. platys among dogs and the possible risk for human infections in Taiwan.

Informing an investment case for Japanese encephalitis vaccine introduction in Bangladesh.

Japanese encephalitis virus (JEV) is a major threat to human health. Bangladesh is considering introducing a JEV vaccine; however, the investment case is hampered by a limited understanding of key aspects of JEV ecology. We conducted a seroprevalence study in a high-incidence region using an assay that limits cross-reactivity with dengue virus. We also trapped mosquitoes and collected information about potential host species. We used mathematical models to recover risk factors for infection and underlying probabilities of severe disease and death. We observed 19.0% [95% confidence interval (CI):17.1 to 21.1] of JEV antibodies. On average, 0.7% (95% CI: 0.2 to 2.0) of the susceptible population gets infected yearly, with pig proximity being the main human infection risk factor. Our traps captured 10 different mosquito species that have been linked with JEV transmission. We estimated that 1 in 1000 infections results in severe disease, 1 in 10,000 results in death, and 76% of severe cases are missed by surveillance.

Multiplex Dual-Target Reverse Transcription PCR for Subtyping Avian Influenza A(H5) Virus.

An increased risk for human infection with avian influenza A(H5N1) viruses is of concern. We developed an internally controlled, dual-target reverse transcription PCR for influenza A(H5) subtyping. This test could be used to detect influenza A(H5) in clinical samples.

Methicillin-resistant Staphylococcus aureus prevalence in food-producing animals and food products in Saudi Arabia: A review.

In Saudi Arabia, the occurrence of methicillin-resistant Staphylococcus aureus (MRSA) in food and livestock represents a major public health hazard. The emergence of livestock-associated MRSA has heightened the risk of human infection with comparable virulence traits. The lack of information about MRSA transmission in our region hinders accurate risk assessment, despite its detection in food animals and retail foods. Adopting a One Health approach is essential for effectively combating MRSA in Saudi Arabia. This method unites actions in the human, animal, and environmental spheres. To combat MRSA contamination, surveillance measures need strengthening; interdisciplinary collaboration among healthcare professionals, veterinarians, and environmental scientists is crucial, and targeted interventions must be implemented in local food chains and animal populations. Through a holistic strategy, public health and sustainable food production in the region are protected. This review aims to improve public health interventions by increasing understanding of MRSA prevalence and related risks in local food chains and animal populations.

Seroprevalence of IgG and IgM Antibodies against Toxoplasma gondii in Dogs in Greece.

Toxoplasmosis, caused by the protozoan Toxoplasma gondii, is a zoonotic disease that affects various animal species, including dogs, that can serve as sentinels for indirectly estimating the environmental contamination. The current study aimed to determine the seroprevalence of T. gondii IgG and IgM antibodies in dogs across different regions of Greece and assess their living area as a potential risk factor. In total, 1282 blood samples were collected from dogs in urban and rural areas of Greece, including Attica and Thessaloniki. Serum samples were tested for T. gondii-specific IgG and IgM antibodies using an indirect immunofluorescent antibody test. A chi-square test was performed to assess the association between seropositivity for T. gondii and geographical location (urban/rural). The overall T. gondii seroprevalence was 47.6%, while the seroprevalence of IgG and IgM antibodies was 34.3% and 22.2%, respectively. Dogs from rural areas exhibited a significantly higher seroprevalence (53.8%) than those from urban areas (43.9%) (p < 0.001), with the estimated odds ratio being equal to 1.49 (95% CI, 1.18 to 1.65) and the relative risk increased by 22.4%. Dogs in Greece are highly exposed to T. gondii, particularly in rural areas. Measures to prevent canine infections are necessary, and basic hygiene practices, such as hand washing after petting dogs, are required to reduce human infection risk and safeguard public health.

Staphylococci, Reptiles, Amphibians, and Humans: What Are Their Relations?

Reptiles and amphibians are largely present in many environments, including domestic areas when they are kept as pet animals. They often harbor zoonotic pathogens, which can pose a serious risk of infection for humans, mainly immunocompromised individuals, the elderly, children, and pregnant women. Several studies have been carried out to verify the role of cold-blooded animals in the epidemiology of some bacteria, mainly Salmonella, whereas scarce attention has been focused on these animals as a source of staphylococci. These bacteria are often antimicrobial-resistant and they act as opportunistic pathogens, which can cause relevant infections in humans and animals, both domestic and wild. Asymptomatic reptiles and amphibians often harbor staphylococcal strains, such as Staphylococcus aureus and coagulase-negative Staphylococcus spp.; however, these bacteria have been associated with clinical conditions that usually appear in animals under stress conditions. In all cases, greater attention should also be focused on staphylococci in cold-blooded animals due to their implications in human and veterinary medicine.

Anthropozoonotic parasitoses of dogs and cats in the urban ecosystem of Vladivostok, Russia

To investigate the role of domestic dogs and cats in the spread of parasitoses in the Vladivostok urban ecosystem. Biological materials from 782 dogs and 189 cats were used in the research, which were examined by methods of complete parasitological autopsy, microscopy and flotation of faecal samples using saturated solutions of zinc sulfate and sodium nitrate.Fourteen parasite taxa have been identified: nematodes (Nematoda) Ancylostoma caninum, Dirofilaria immitis, Toxascaris leonina, Toxocara canis, T. mystax, Uncinaria stenocephala, Taenia sp., T. hydatigena; tapeworms (Cestoda) Diphyllobothrium latum, Dipylidium caninum, Hydatigera taeniaeformis; flukes (Trematoda) Metagonimus sp.; and parasitic alveolates (Conoidasida) Cystoisospora sp., C. felis. The paper presents the values of the prevalence of infection and statistical reliability of their differences for different groups of animals, depending on gender and age. Nematodes were the core taxa of the parasitofauna identified. Explanations for the results obtained are offered and possible sources of human infection are described. Despite the fact that parasitic‐faunal complexes in the ecosystem of a modern city are much less branched and represented by fewer species than in the wild, there remains a high risk of human infection with zoonotic parasites in urban biocenoses due to the high level of intensive population interactions. Therefore, there is a requirement of high alertness of supervisory authorities in relation to anthropozoonotic parasitoses in an urban environment.

Relative abundance and the fate of human rotavirus in wastewater during treatment processes: identification of potential infectious rotavirus in the final effluents and receiving aquatic milieu in Durban area, South Africa

The occurrence and persistence of rotaviruses in raw and treated wastewater and their discharge into rivers represent a significant health risk for humans and animals, worldwide. In this study, samples were collected monthly from each of the four Durban wastewater treatment plants (DWWTPs) and receiving rivers for a period of 3 months. Rotavirus was quantified by real-time quantitative PCR (RT-qPCR), and viability was assessed using integrated cell culture (ICC)-qPCR. Rotavirus was detected consistently in 100% of influent wastewaters (mean concentration range, 4.36–4.46 log10 genome equivalent (GE) copies/L) and final effluent samples of three DWWTPs (range, 3.35–3.61 log10 GE copies/L). Overall, 94% (45/48) of the wastewater analyzed and 95% (20/21) of the associated river water samples were positive for rotavirus (range, 2.04–6.77 log10 GE copies/L). The activated sludge process with 0.10–0.43 log10 reduction values (LRV) only moderately reduced the viral loads. Similarly, one of the DWWTPs that operated the biofilter modality produced 0.20 LRV. Though the additional treatment with chlorine produced higher LRV (range, 0.31–0.53) than the corresponding activated sludge or biofilter process, the difference in viral removals was not significant (p > 0.05). The equivalent treatment efficiencies of the four DWWTPs varied from 19 to 43% decay in the population of rotavirus. Further, infectious rotavirus ranging from 66.67 to 100%, 50 to 100%, and 66.67 to 100% were detected in the post-activated sludge, final effluents, and river water samples, respectively. In conclusion, the findings of infectious rotavirus in both the final effluents and associated rivers represent an infection risk for humans or animals during contact. Thus, close monitoring for rotavirus and risk assessment studies under distinct exposure scenarios may further shed light on the health-related risks associated with water recovery and reuse in urban settings.

Evaluation of chimeric recombinant antigens for the serodiagnosis of Trypanosoma cruzi in dogs: a promising tool for Chagas disease surveillance

BackgroundChagas disease (CD), a neglected parasitic disease caused by Trypanosoma cruzi, poses a significant health threat in Latin America and has emerged globally because of human migration. Trypanosoma cruzi infects humans and over 100 other mammalian species, including dogs, which are important sentinels for assessing the risk of human infection. Nonetheless, the serodiagnosis of T. cruzi in dogs is still impaired by the absence of commercial tests. In this study, we investigated the diagnostic accuracy of four chimeric recombinant T. cruzi IBMP antigens (IBMP-8.1, IBMP-8.2, IBMP-8.3, and IBMP-8.4) for detecting anti-T. cruzi antibodies in dogs, using latent class analysis (LCA).Methods We examined 663 canine serum samples, employing indirect ELISA with the chimeric antigens. LCA was utilized to establish a latent variable as a gold standard for T. cruzi infection, revealing distinct response patterns for each antigen.Results The IBMP (Portuguese acronym for the Molecular Biology Institute of Paraná) antigens achieved area under the ROC curve (AUC) values ranging from 90.9% to 97.3%. The highest sensitivity was attributed to IBMP-8.2 (89.8%), while IBMP-8.1, IBMP-8.3, and IBMP-8.4 achieved 73.5%, 79.6%, and 85.7%, respectively. The highest specificity was observed for IBMP-8.4 (98.6%), followed by IBMP-8.2, IBMP-8.3, and IBMP-8.1 with specificities of 98.3%, 94.4%, and 92.7%, respectively. Predictive values varied according to prevalence, indicating higher effectiveness in endemic settings.Conclusions Our findings underscore the remarkable diagnostic performance of IBMP-8.2 and IBMP-8.4 for the serodiagnosis of Trypanosoma cruzi in dogs, representing a promising tool for the diagnosis of CD in dogs. These chimeric recombinant antigens may not only enhance CD surveillance strategies but also hold broader implications for public health, contributing to the global fight against this neglected tropical disease.Graphical