Epidemiology and diversity of gastrointestinal tract helminths of wild ruminants in sub-Saharan Africa: a review.

This review summarises studies on distribution, diversity, and prevalence of gastrointestinal helminth infections in wild ruminants in sub-Saharan Africa. The results showed that 109 gastrointestinal tract (GIT) helminth species or species complexes were recorded in 10 sub-Saharan African countries. South Africa reported the highest number of species because most studies were carried out in this country. Eighty-eight nematode species or species complexes were recorded from 30 wild ruminant species across eight countries. The genus Trichostrongylus recorded the highest number of species and utilised the highest number of wild ruminant species, and along with Haemonchus spp., was the most widely distributed geographically. Fifteen trematode species or species complexes were reported from seven countries. The genus Paramphistomum recorded the highest number of species, and Calicophoron calicophoron was the most commonly occurring species in sub-Saharan African countries and infected the highest number of hosts. Six cestode species or species complexes from one family were documented from 14 wild hosts in seven countries. Moniezia spp. were the most commonly distributed in terms of host range and geographically. Impala were infected by the highest number of nematodes, whilst Nyala were infected by the highest number of trematode species. Greater kudu and Impala harbored the largest number of cestodes. The prevalence amongst the three GIT helminths taxa ranged between 1.4% and 100% for nematodes, 0.8% and 100% for trematodes, and 1.4% and 50% for cestodes. There is still limited information on the distribution and diversity of GIT helminths in wild ruminants in most sub-Saharan African countries.

Equine helminths: prevalence and associated risk factors in Gamo Gofa Zone, Ethiopia.

IMPORTANCE: Equines are indispensable in reducing the huge burden on children and women and income generation. On the other hand, minimal attention is given to improving their health and welfare. OBJECTIVE: This study examined the prevalence and associated risk factors of helminth parasites of equine in the Gamo Gofa Zone. METHODS: A cross-sectional study was employed from June 2019 to March 2020. The study districts and Kebeles were selected purposively based on agroecology whereas selection of study households and animals were performed based on simple random sampling techniques. Identification of nematode, trematode parasite ova and larvae of D. arnfieldi were done by floatation, sedimentation, and Baermann techniques respectively. Descriptive statistics and logistic regression was applied to estimate the prevalence and association of risk factors with helminth parasites. RESULTS: The overall helminth parasite prevalence in the study area was 90.4%, 425/470 (95% [CI], 87.16-92.9). The prevalence of Strongyle, Fasciola, O. equi, P. equorum, D. arnfieldi, and mixed parasite infections were 65.1%, 21.7%, 17.4%, 34%, 34%, and 58.1%, respectively. Infections from Fasciola species and D. arnfieldi infection were four ([AOR], 4.4; 95% CI, 2-9.4) and two times (AOR, 2; 95% CI, 1.1-3.6) respectively more likely occur in donkeys than in mules. The occurrence of Strongyle species in midland agroecology was two times (AOR, 2.6; 95% CI, 1.4-4.7) more likely than lowland agroecology. CONCLUSIONS AND RELEVANCE: The present study identified diverse species of equine helminth parasites that necessitate urgent disease control and prevention measures.

Does the body size, sex, and reproductive modes of leaf litter anurans affect the diversity of parasites?

We describe the composition of endoparasites associated with leaf litter anurans from an Atlantic Forest area, in southeastern Brazil. We tested if body size, sex, and reproductive modes of anuran hosts influence endoparasite abundance and richness. We sampled 583 individuals from 11 anuran species and recorded 1,600 helminths from 14 taxa. The helminths that infected the greatest number of anuran host species were the nematodes Cosmocerca parva (8 spp.), Physaloptera sp. (8 spp.), and Cosmocerca brasiliense (7 spp.), and the most abundant helminth species were Physaloptera sp. (14.6%), Cosmocerca brasiliense (13.7%) and Cosmocerca parva (12.6%). Both helminth abundance and richness were positively affected by anuran body size and dependence on water for reproduction. Larger hosts can contain a higher abundance of parasites because they may provide more physical space than smaller ones, or it can simply be a function of age. Besides, parasite species richness can be highly correlated with the amount of time a host spends in association with aquatic habitats, a conservative aspect of both parasite and host natural history. Within host species, there was a positive and significant influence of body size on helminth abundance. Haddadus binotatus females had greater helminth abundance than males, probably due to sex-related differences in behavior and/or in physiology. Our data suggest that reproductive modes could also influence helminth infection parameters in other anuran communities and should be considered in detail in future analyses.

Metabarcoding of protozoa and helminth in black-necked cranes: a high prevalence of parasites and free-living amoebae.

Parasites and free-living amoebae (FLA) are common pathogens that pose threats to wildlife and humans. The black-necked crane (Grus nigricollis) is a near-threatened species and there is a shortage of research on its parasite diversity. Our study aimed to use noninvasive methods to detect intestinal parasites and pathogenic FLA in G. nigricollis using high-throughput sequencing (HTS) based on the 18S rDNA V9 region. A total of 38 fresh fecal samples were collected in Dashanbao, China, during the overwintering period (early-, middle I-, middle II-, and late-winter). Based on the 18S data, eight genera of parasites were identified, including three protozoan parasites: Eimeria sp. (92.1%) was the dominant parasite, followed by Tetratrichomonas sp. (36.8%) and Theileria sp. (2.6%). Five genera of helminths were found: Echinostoma sp. (100%), Posthodiplostomum sp. (50.0%), Euryhelmis sp. (26.3%), Eucoleus sp. (50.0%), and Halomonhystera sp. (2.6%). Additionally, eight genera of FLA were detected, including the known pathogens Acanthamoeba spp. (n = 13) and Allovahlkampfia spp. (n = 3). Specific PCRs were used to further identify the species of some parasites and FLA. Furthermore, the 18S data indicated significant changes in the relative abundance and genus diversity of the protozoan parasites and FLA among the four periods. These results underscore the importance of long-term monitoring of pathogens in black-necked cranes to protect this near-endangered species.

Title: Métabarcoding des protozoaires et des helminthes chez les grues à cou noir : forte prévalence de parasites et d'amibes libres. Abstract: Les parasites et les amibes libres sont des agents pathogènes courants qui constituent une menace pour la faune et les humains. La grue à cou noir (Grus nigricollis) est une espèce quasi menacée et les recherches sur sa diversité parasitaire sont insuffisantes. Notre étude visait à utiliser des méthodes non invasives pour détecter les parasites intestinaux et les amibes libres pathogènes chez G. nigricollis en utilisant le séquençage à haut débit basé sur la région V9 de l'ADNr 18S. Au total, 38 échantillons de matières fécales fraîches ont été collectés à Dashanbao, en Chine, au cours de la période d'hivernage (début, milieu I, milieu II et fin de l'hiver). Sur la base des données 18S, huit genres de parasites ont été identifiés, dont trois parasites protozoaires : Eimeria sp. (92,1 %) était le parasite dominant, suivi de Tetratrichomonas sp. (36,8 %) et Theileria sp. (2,6 %). Cinq genres d'helminthes ont été trouvés : Echinostoma sp. (100 %), Posthodiplostomum sp. (50,0 %), Euryhelmis sp. (26,3 %), Eucoleus sp. (50,0 %) et Halomonhystera sp. (2,6 %). De plus, huit genres d'amibes libres ont été détectés, y compris les agents pathogènes connus Acanthamoeba spp. (n = 13) et Allovahlkampfia spp. (n = 3). Des PCR spécifiques ont été utilisées pour identifier davantage les espèces de certains parasites et amibes libres. En outre, les données 18S ont indiqué des changements significatifs dans l'abondance relative et la diversité des genres des parasites protozoaires et des amibes au cours des quatre périodes. Ces résultats soulignent l'importance de la surveillance à long terme des agents pathogènes chez les grues à cou noir pour protéger cette espèce quasi menacée.

Endoparasitic helminth fauna and diet of Geophagus sveni (Pisces) in Upper Paraná River basin.

In freshwater ecosystems, parasite infection patterns are influenced by factors including spatial-temporal variations, host diet, and habitat. Fish often change diets, affecting their parasite communities. This study focused on non-native host fish Geophagus sveni, aiming to characterize diet and endoparasitic helminth fauna patterns in the invaded area, investigating spatial and seasonal possible differences of endoparasite infections and correlating with host diet, in São José dos Dourados River and Tietê River areas. The host fish were collected in these areas during the dry and rainy season using gillnets. The endoparasites were collected and preserved in alcohol and identified using taxonomic methods, and stomach contents were examined for diet analysis. Parasitism descriptors were calculated and evaluated spatially and seasonally by ANOVA and the Kruskal-Wallis tests. PERMANOVA assessed G. sveni diet differences, and RDA correlated the endohelminth abundance with the host diet. Two endoparasites were recorded: metacercariae of Austrodiplostomum compactum (Trematoda) and larvae and adults of Raphidascaris (Sprentascaris) lanfrediae (Nematoda). Spatial differences were observed for the mean abundance and prevalence of R. (S.) lanfrediae and A. compactum prevalence. Seasonal variations of parasitic descriptors occurred for the nematode in the Tietê River area. The detritus and aquatic insects were the most consumed items by G. sveni. Detritus consumption positively correlates with nematode abundance. The findings indicate that factors such as artificial channels and rainfall, which can influence resource availability, may affect the fish's diet and potentially influence the structure of its endoparasite community. The study emphasizes the importance of understanding trophic chain-transmitted parasites and calls for further research in Neotropical environments.

First molecular insights into gastrointestinal helminths of domestic birds in the Caspian Sea Littoral of Iran with an emphasis on the One Health concern.

The current investigation was carried out during the period from July 2022 to March 2023, aiming to investigate the prevalence of gastrointestinal helminths in domestic birds collected from traditional markets in Guilan province. One hundred forty-eight domestic birds, including chickens (Gallus gallus domesticus), domestic ducks (Anas platyrhynchos domesticus), greylag geese (Anser anser), and domestic turkeys (Meleagris gallopavo domesticus) were examined. Totally, 42.56% of the investigated birds were positive for helminthic parasites. Morphological analysis revealed varying infection rates among birds: Echinostoma revolutum (5.40%), Hypoderaeum conoideum (2.02%), Cloacotaenia megalops (0.67%), Hymenolepididae family (4.05%), Ascaridia galli (16.89%), and Heterakis gallinarum (4.72%). The investigation involved molecular analysis of the 18S and ITS1 + 5.8S + ITS2 rRNA gene regions. The findings indicated that the 18S region of nematode isolates exhibited a similarity of 92 to 100% with sequences in the GenBank, whereas trematode and cestode isolates showed a gene similarity ranging from 88 to 99%. The ITS regions of nematode, trematode, and cestode isolates exhibited genetic similarities ranging from 87 to 100%, 73-99%, and 75-99%, respectively. Furthermore, phylogenetic analysis confirmed the categorization of the identified species within the Ascaridiidae, Heterakidae, Hymenolepididae, and Echinostomatidae families, indicating their close affinity with previously documented species. Implementing precise control measures such as consistent monitoring, adequate sanitation protocols, and administering anthelmintic treatments is crucial for effectively managing parasitic infections in free-range and backyard poultry farms. Additionally, conducting further surveys is advisable to assess the impact of these parasites on the health and productivity of poultry in the investigated area.

Estimating Prevalence and Infection Intensity of Soil-Transmitted Helminths Using Quantitative Polymerase Chain Reaction and Kato-Katz in School-Age Children in Angola.

Quantitative polymerase chain reaction (qPCR) is gaining recognition in soil-transmitted helminth (STH) diagnostics, especially for Strongyloides stercoralis and differentiating hookworm species. However, sample preservation and DNA extraction may influence qPCR performance. We estimated STH prevalence and infection intensity by using qPCR in schoolchildren from Huambo, Uige, and Zaire, Angola, and compared its performance with that of the Kato-Katz technique (here termed Kato-Katz). Stool samples from 3,063 children (219 schools) were preserved in 96% ethanol and analyzed by qPCR, of which 2,974 children (215 schools) had corresponding Kato-Katz results. Cluster-adjusted prevalence and infection intensity estimates were calculated by qPCR and Kato-Katz, with cycle threshold values converted to eggs per gram for qPCR. Cohen's kappa statistic evaluated agreement between qPCR and Kato-Katz. DNA extraction and qPCR were repeated on 191 (of 278) samples that were initially qPCR negative but Kato-Katz positive, of which 112 (58.6%) became positive. Similar prevalence for Ascaris lumbricoides (37.5% versus 34.6%) and Trichuris trichiura (6.5% versus 6.1%) were found by qPCR and Kato-Katz, respectively, while qPCR detected a higher hookworm prevalence (11.9% versus 2.9%). The prevalence of moderate- or high-intensity infections was higher by Kato-Katz than by qPCR. Agreement between qPCR and Kato-Katz was very good for A. lumbricoides, moderate for T. trichiura, and fair for hookworm. Strongyloides stercoralis prevalence was 4.7% (municipality range, 0-14.3%), and no Ancylostoma ceylanicum was detected by qPCR. Despite suboptimal performance, presumably due to fixative choice, qPCR was fundamental in detecting S. stercoralis and excluding zoonotic A. ceylanicum. Further evaluations on sample fixatives and DNA extraction methods are needed to optimize and standardize the performance of qPCR.

Searching for common patterns in parasite ecology: species and host contributions to beta-diversity in helminths of South African ungulates and fleas of South American rodents.

We searched for common patterns in parasite ecology by investigating species and host contributions to the beta-diversity of infracommunities (=assemblages of parasites harboured by a host individual) in helminths of three species of South African ungulates and fleas of 11 species of South American rodents, assuming that a comparison of patterns in distinctly different parasites and hosts would allow us to judge the generality or, at least, commonness of these patterns. We used data on species' composition and numbers of parasites and asked whether (i) parasite species' attributes (life cycle, transmission mode, and host specificity in helminths; possession of sclerotized combs, microhabitat preference, and host specificity in fleas) or their population structure (mean abundance and/or prevalence) and (ii) host characteristics (sex and age) affect parasite and host species' contributions to parasite beta-diversity (SCBD and HCBD, respectively). We found that parasite species' morphological and ecological attributes were mostly not associated with their SCBD. In contrast, parasite SCBD, in both ungulates and rodents, significantly increased with either parasite mean abundance or prevalence or both. The effect of host characteristics on HCBD was detected in a few hosts only. In general, parasite infracommunities' beta-diversity appeared to be driven by variation in parasite species rather than the uniqueness of the assemblages harboured by individual hosts. We conclude that some ecological patterns (such as the relationships between SCBD and parasite abundance/prevalence) appear to be common and do not differ between different host-parasite associations in different geographic regions, whereas other patterns (the relationships between SCBD and parasite species' attributes) are contingent and depend on parasite and host identities.

A Comparison of Markov and Mechanistic Models for Soil-Transmitted Helminth Prevalence Projections in the Context of Survey Design.

Globally, there are over 1 billion people infected with soil-transmitted helminths (STHs), mostly living in marginalized settings with inadequate sanitation in sub-Saharan Africa and Southeast Asia. The World Health Organization recommends an integrated approach to STH morbidity control through improved access to sanitation and hygiene education and the delivery of preventive chemotherapy (PC) to school-age children delivered through schools. Progress of STH control programs is currently estimated using a baseline (pre-PC) school-based prevalence survey and then monitored using periodical school-based prevalence surveys, known as Impact Assessment Surveys (IAS). We investigated whether integrating geostatistical methods with a Markov model or a mechanistic transmission model for projecting prevalence forward in time from baseline can improve IAS design strategies. To do this, we applied these 2 methods to prevalence data collected in Kenya, before evaluating and comparing their performance in accurately informing optimal survey design for a range of IAS sampling designs. We found that, although both approaches performed well, the mechanistic method more accurately projected prevalence over time and provided more accurate information for guiding survey design. Both methods performed less well in areas with persistent STH hotspots where prevalence did not decrease despite multiple rounds of PC. Our findings show that these methods can be useful tools for more efficient and accurate targeting of PC. The general framework built in this paper can also be used for projecting prevalence and informing survey design for other neglected tropical diseases.

Soil-transmitted helminths and associated factors among pregnant women in Doreni district, Oromia region, Ethiopia: a cross-sectional study.

BACKGROUND: Soil-transmitted helminthiasis (STH) refers to a set of parasitic illnesses caused by nematode worms and spread to people through faeces-contaminated soil. It is highly prevalent in low- and middle-income countries due to a lack of environmental sanitation and personal hygiene. Pregnant women are among the risk groups for infection by soil-transmitted helminths. Former studies of the disease burden among pregnant women in Ethiopia didn't indicate the intensity of parasitic infection. The aim of this study was to assess the prevalence and associated factors of soil-transmitted helminths among pregnant women. METHODS: An institution-based cross-sectional study was conducted among 416 randomly selected pregnant women. The data were collected using a structured interview-administered questionnaire and a laboratory test. The Kato-Katz technique was used to diagnose soil-transmitted helminthiasis and determine the intensity of the infection. The collected data were entered into Epi-Data version 4.6 and exported to SPSS version 25 for analysis. Multivariate logistic regression analysis was used to identify independent predictors of soil-transmitted helminths at a p-value < 0.05. RESULTS: The overall prevalence of soil-transmitted helminths among pregnant women was 30%. (95%, CI: 26-34%). Living in a rural area (AOR = 3.35; 95% CI = 1.83-6.13), drinking from an unprotected water source (AOR = 2.52; 95% CI = 1.45-4.37), not washing one's hand after the toilet (AOR = 2.75; 95% CI = 1.55-4.88), lacking health information (AOR = 1.70; 95% CI = 1.01-2.85), working as a daily labourer (AOR = 2.88; 95% CI = 1.01-8.20), and walking barefoot (AOR = 4.00; 95% CI = 2.29-7.00) were significantly associated with the presence of soil-transmitted helminths among pregnant women. CONCLUSION: The prevalence of STH was significantly moderate in the study area, where pregnant women were mostly affected by ascariasis and hookworms. Living in a rural area, being a daily labourer, walking barefoot, not washing hands after the toilet, drinking from an unprotected water source, and lacking health information were the determining factors. Interventions including health education, the expansion of pure drinking water sources, the promotion of personal hygiene, and the wearing of shoes are recommended to reduce the burden of soil-transmitted helminths in the study area.

Persistence of pathogens and bacterial community dynamics in tropical soil after application of raw sewage.

The objective of this work was to evaluate the persistence of faecal indicators and pathogenic organisms (Salmonella spp., Escherichia coli and viable helminth eggs) and the structure/diversity of bacterial communities in soil receiving raw sewage (RS) for an extended period of application (3 uninterrupted years). In the experimental design, three treatments were defined: (1) Control soil, characterized by the analysis of a composite sample collected in an area of similar soil, but not a recipient of RS (TSC); (2) Soil receiving conventional mineral fertilization, and furrow irrigation with supply water (TW); and (3) Fertirrigated soil with RS applied by furrows (TF). The results of persistence of pathogenic organisms and indicators in TF indicated a sanitary quality similar to the control soil (TSC), thus potentially bringing low risks of contamination with pathogens present in the soil. The presence of viable helminth eggs was not identified in any treatment studied, because of its low concentration in the raw sewage of the studied system. The TW, TF and TSC treatments had 34.8% of bacterial diversity in common. The bacterial composition of the soil showed a predominance of the Proteobacteria phylum in all treatments studied; however, TF was the one with the highest relative abundance of this phylum (44.8%).

First helminthological data on the Iberian adder, Vipera seoanei.

The helminth fauna present in the gut contents of Iberian adders, Vipera seoanei (Squamata: Viperidae), were characterised and analysed in respect to biological and eco-geographic factors that may affect the occurrence and diversity of helminths in this species. A total of 317 samples of preserved stomachs and intestines, covering the distributional range of V. seoanei, were examined. Similar to other Vipera species from the Iberian Peninsula, the helminth fauna was also impoverished in V. seoanei, but unlike other Vipera species from Central and East Europe, helminths were mostly found in adult vipers, and occurred in vipers located at the periphery of the species range, characterised by low elevation, high temperature and precipitation levels, and abundant pastures.

Status of Helminthic Infections in Residents around River Basins in the Republic of Korea for 10 Years (2011-2020).

The positive rate of Clonorchis sinensis is the highest among intestinal parasites in the Republic of Korea (Korea). More than 1.2 million people were at risk of C. sinensis infection in Korea in 2012. An intensive control program is being implemented for residents of the 5 major river basins to reduce helminthic infections, including C. sinensis infection. This study evaluated the continuous intensive control program for parasitic diseases including clonorchiasis in areas near the 5 major river basins in Korea over the past 10 years (2011-2020). A total of 335,020 fecal samples (one sample per resident) prepared by the modified sedimentation technic were microscopically examined. Those who expelled helminth eggs were treated with anthelmintics through local health centers and re-examined 3 months later. The overall positive rate of helminths egg was 7.1%. The annual positive rates were dramatically decreased from 14.4% (2011) to 5.9% (2020). The egg positive rate was highest in C. sinensis (5.3%), followed by heterophyid flukes (1.5%) and Trichuris trichiura (0.2%). The prevalence of C. sinensis was significantly higher in males (7.6%) than in females (3.7%), and the highest in the 50-59 years (7.0%) age group. Our results are beneficial to establish prevention and control policies against helminthiases including clonorchiasis in endemic areas in this country.

Using quantitative PCR to identify opportunities to strengthen soil-transmitted helminth control in Solomon Islands: A cross-sectional epidemiological survey.

BACKGROUND: The Kato-Katz microscopy technique is the global standard for assessment of soil-transmitted helminth (STH) burden. However, major limitations include its poor sensitivity, requirement for rapid sample processing, and inability to differentiate hookworm species nor detect Strongyloides spp. infections. We assessed the prevalence and intensity of STH species in Solomon Islands by conducting a province-wide survey using quantitative PCR (qPCR) for diagnosis, which can provide much better characterisation of STH burden than microscopy. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a cross-sectional survey in 18 villages in Western Province to detect infections with six STH species and quantify intensity with three. We used linear mixed model regression to identify potential water, sanitation, and hygiene (WASH) and environmental risk factors for infection. We collected stool specimens from 830 village residents. Overall STH prevalence was 63.3% (range 27.5 to 91.5% across villages), led by Necator americanus (54.5% [range 17.5-89.4%]), followed by Ancylostoma ceylanicum (15.5% [range 2.8-45.8%]), Trichuris trichiura (9.1% [range 0-79.2%]), and Strongyloides spp. (3.2% [range 0-29.2%]). Most infections were of light intensity for N. americanus (85.7%) and T. trichiura (90.7%). Owning a household latrine was associated with a lower risk of N. americanus infection (AOR 0.41, 95% CI 0.24-0.68) while greater precipitation was linked to more common T. trichiura infection (AOR 1.14, 95% CI 1.04-1.25). CONCLUSION/SIGNIFICANCE: In this first large-scale population survey of STH in the Pacific using qPCR, we found evidence that ivermectin should be incorporated into STH control programmes because of the presence of T. trichiura and Strongyloides spp., both of which are poorly responsive to albendazole. Furthermore, One Health strategies are needed for improved A. ceylanicum and Strongyloides spp. control, WASH access and use should be improved to complement deworming programmes, and control efforts should ideally be expanded to entire communities. TRIAL REGISTRATION: ClinicalTrials.gov Australian and New Zealand Clinical Trials Registry ACTRN12618001086257.

Impact of ivermectin mass drug administration on burden of soil-transmitted helminths in onchocerciasis control and elimination programs, Yeki district, southwest Ethiopia.

Community-directed treatment with ivermectin (CDTi) is the primary strategy employed to control and eliminate human onchocerciasis in Ethiopia. After long-term mass distribution for onchocerciasis, ivermectin is expected to have additional benefits beyond the envisioned targets by reducing the burden of other co-endemic parasitic infections as to STHs. To date, studies focused on the collateral impact of CDTi on STH in Ethiopia are scanty. Two community-based cross-sectional surveys (baseline in 1997 and post-CDTi in 2017) were conducted to evaluate the impact of long-term CDTi employed to control and eliminate onchocerciasis on the burden of STH infections in Yeki district of southwest Ethiopia. Stool samples were collected and examined using Ritchie`s concentration and Kato-Katz techniques in the baseline and current study, respectively. Overall, 188(38.3%, 95% Confidence interval (CI) 34.1-42.7%) individuals were positive at least for any of the STH species from 491 study participants in the post-CDTi. The prevalence of A. lumbricoides, hookworms, and T. trichiura was 11.2% (95% CI 8.7-14.3%), 16.3% (95% CI 13.3-19.8%), and 29.9% (95% CI 26.1-34.1%), respectively. Individuals aged 5-9 years had a significantly higher prevalence of A. lumbricoides (Adjusted odds ratio (AOR) 6.5, 95% CI 1.7-25.4), T. trichuria (AOR 8, 95% CI 2.6-25.1), and any STH infection (AOR 5, 95% CI 1.7-14.7) than those of ≥ 51 years. Also, significantly higher prevalences of T. trichuria infection were observed in individuals aged 10-14 years (AOR 4.1, 95% CI 1.7-9.9), 15-20 years (AOR 3.1, 95% CI 1.2-8.1), 21-30 years (AOR 2.4, 95% CI 1.1-5.5), and 31-40 years (AOR 3.2, 95% CI 1.3-7.5) compared with those of ≥ 51 years. The prevalence of A. lumbricoides was significantly higher in males (AOR 0.5, 95% CI 0.3-0.9). Of the 491 study participants, only data from 400 individuals who had not been involved in a mass drug administration (MDA) with other STH anthelmintics were considered in the comparative analysis. Before CDTi, the prevalence of A. lumbricoides, T. trichiura, hookworm, and any STH infection was 47.1% (95% CI 41.6-52.7%), 3.3% (95% CI 1.8-5.9%), 37.9% (95% CI 32.7-43.5%), and 58.8% (95% CI 53.2-64.1%), respectively. Long-term CDTi considerably reduced the prevalences of A. lumbricoides and hookworm by 76.2% and 56.9%, respectively (p < 0.001). Nonetheless, CDTi did not affect the prevalence of T. trichiura infection and, in contrast, it was significantly higher in the current study (P < 0.001). Overall post-CDTi prevalence of any STH infection was considerably lower than reported in the baseline (p < 0.001). It is evidenced that long-term CDTi for onchocerciasis control and elimination had additional benefits by reducing the prevalence of STH infections specifically of A. lumbricoides and hookworm, but had no impact on infections with T. trichuria. Our finding of additional health benefits of large-scale ivermectin administration taking it will aid to increase positive engagement and sustain participation of communities during MDA campaigns, and strengthen governmental and non-governmental organizations (NGOs) support for the undergoing national onchocerciasis elimination program.

Hematodinium sp. infection does not drive collateral disease contraction in a crustacean host.

Host, pathogen, and environment are determinants of the disease triangle, the latter being a key driver of disease outcomes and persistence within a community. The dinoflagellate genus Hematodinium is detrimental to crustaceans globally - considered to suppress the innate defences of hosts, making them more susceptible to co-infections. Evidence supporting immune suppression is largely anecdotal and sourced from diffuse accounts of compromised decapods. We used a population of shore crabs (Carcinus maenas), where Hematodinium sp. is endemic, to determine the extent of collateral infections across two distinct environments (open-water, semi-closed dock). Using a multi-resource approach (PCR, histology, haematology, population genetics, eDNA), we identified 162 Hematodinium-positive crabs and size/sex-matched these to 162 Hematodinium-free crabs out of 1191 analysed. Crabs were interrogated for known additional disease-causing agents; haplosporidians, microsporidians, mikrocytids, Vibrio spp., fungi, Sacculina, trematodes, and haemolymph bacterial loads. We found no significant differences in occurrence, severity, or composition of collateral infections between Hematodinium-positive and Hematodinium-free crabs at either site, but crucially, we recorded site-restricted blends of pathogens. We found no gross signs of host cell immune reactivity towards Hematodinium in the presence or absence of other pathogens. We contend Hematodinium sp. is not the proximal driver of co-infections in shore crabs, which suggests an evolutionary drive towards latency in this environmentally plastic host.

Endoparasitism of Golden Retrievers: Prevalence, risk factors, and associated clinicopathologic changes.

Endoparasitism is a common disease in dogs throughout their lifetime despite the widespread availability of inexpensive diagnostic tests and effective treatments. The consequences of host parasite interactions in otherwise apparently healthy dogs remains largely unknown. This cross-sectional study used complete blood count, serum biochemistry, and fecal flotation data collected from 3,018 young dogs (<3 years of age) enrolled within the Morris Animal Foundation Golden Retriever Lifetime Study (GRLS) to determine the prevalence of endoparasitism and compare bloodwork values of parasite positive and negative participants using logistic regression. Variables including age, gender, reproductive status, and geographic region at the time of evaluation were assessed to identify potential associations. To the authors' knowledge, a comprehensive assessment of clinicopathological changes associated with endoparasite infection in a large cohort has not been completed in the recent decade. The overall prevalence of endoparasitism was 6.99% (211/3018). Dogs who were parasite positive had statistically lower albumin (P = 0.004), lower RBC count (P = 0.01), higher neutrophil count (P = 0.002), and higher platelet count (P <0.001) as compared to parasite negative dogs. It was also concluded that dogs living in rural areas were more likely to have endoparasites than those living in suburban areas. Epidemiological data is crucial for the design and monitoring of prevention and control strategies. Identification of endoparasites by fecal testing is an essential tool to identify susceptible and resistant animals that can act as spreaders and reservoirs of intestinal parasites thereby enabling appropriate therapy and reducing the risk of new infection to animals and humans. Further epidemiological studies are needed to prevent, monitor, and develop new strategies to control endoparasites.

Necropsies disclose a low helminth parasite diversity in periurban howler monkeys.

Primate-parasite interactions are often investigated via coprological studies given ethical and conservation restrictions of collecting primate hosts. Yet, these studies are inadequate to recover adult helminths for taxonomic identification and to accurately assess their prevalence, intensity, abundance, and site of infection. Fresh carcasses found in anthropogenic landscapes come as informative and reliable alternatives. In this study, we identified the helminths of brown howler monkeys (Alouatta guariba clamitans) and their sites of infection, and measured their prevalence, intensity, and abundance of infection. We necropsied 18 adult males, 11 adult females, and 7 juvenile males that died in conflicts with the anthropogenic environment (domestic dog attacks, n = 11; electrocutions and road-kills, n = 10 each; unknown, n = 5) in periurban landscapes of southern Brazil between 2013 and 2019. We found three nematodes (Trypanoxyuris minutus, Dipetalonema gracile, and Parabronema bonnei) and one cestode (Bertiella cf. studeri), a diversity estimated to account for a sampling completeness of 99%. Prevalence ranged from 3% for P. bonnei to 100% for T. minutus. Mean abundance ranged from 2 (D. gracile and B. cf. studeri) to 55,116 (T. minutus) and mean intensity of infection ranged from 4 (B. cf. studeri) to 55,116 (T. minutus). Trypanoxyuris minutus sex ratio was strongly male-biased. The intensity of infection with T. minutus was higher in juvenile males and adult females than in adult males. The low parasite diversity and the helminths' mode of transmission are compatible with howlers' arboreality and folivorous-frugivorous diet. The howlers were not infected with soil-transmitted helminth parasites of humans and domestic animals on the ground and probably did not eat invertebrates to complement the diet. Given the lack of evidence of howler health problems, we suggest that the causes of death of the necropsied howlers are the major threats to the long-term conservation of the species at the study periurban landscapes.

HELMINTH DIVERSITY OF GREEN TREEFROGS (HYLA CINEREA) IN THEIR EXPANDED GEOGRAPHICAL RANGE.

There has been a growing interest in characterizing the parasite faunas of species populations as they expand their geographical ranges as a result of climate change. Expanded-range populations often exhibit lower parasite diversity than historical-range populations, and reduced parasitism may, in part, be attributable to expanded-range populations escaping their native range parasites. The present study compares the helminth faunas of green treefrogs (Hyla cinerea) from 4 historical and 4 expanded-range populations to determine whether these latter populations have undergone parasite escape. Results of this study found relatively high degrees of similarity in species composition among helminth assemblages within historical or within range-expansion locations, with marked differences in the composition of helminth faunas between historical and expanded-range populations of these frogs. Because green treefrogs from expanded-range locations exhibited significant decreases in helminth species diversity compared with those from historical sites, they appear to be escaping levels of parasitism typically experienced by these frogs in their native range. Most notably, there was a decrease in the abundance of helminths with direct life cycles and the absence of trematode assemblages with indirect life cycles among expanded-range populations of H. cinerea. The low prevalence of trematode assemblages among historical populations of green treefrogs could limit these parasites' ability to be introduced and propagated in expanded-range locations. However, the lack of trematode assemblages among populations of H. cinerea in its expanded range may also be due to the absence or limited availability of other aquatic hosts that are required to complete the life cycles of these parasites. The reduction in helminth diversity among expanded-range populations of green treefrogs lends some credence to the notion that individuals at the front of a range expansion often invest less energy in reproduction and in doing so allocate more energy to dispersal and other life-history traits, including resistance to parasites. There may, however, be other explanations for differences in parasite species diversity between historical and expanded-range populations of H. cinerea. Because many of the helminths reported from this study are host generalists of amphibians whose recruitment and transmission among intermediate and paratenic hosts are known to be constrained by water and/or soil moisture conditions, we cannot ignore the role of both local amphibian diversity and local abiotic factors in influencing helminth diversity between the 2 population types of green treefrogs. These latter factors would decrease the role of parasite escape or energy trade-offs in driving helminth diversity among populations of H. cinerea and instead would suggest that local conditions play a more prominent role in structuring their helminth communities.

Soil-transmitted helminth infections and nutritional indices among Filipino schoolchildren.

BACKGROUND: Soil-transmitted helminth (STH) infections are still prevalent among schoolchildren in the Philippines. We evaluated the risk factors associated with STH and the relationship between STH and nutritional indices among schoolchildren aged 9-10 years in Laguna province, the Philippines. METHODS: We used the baseline data from 40 schools enrolled in a randomised controlled trial of the Magic Glasses Philippines health education package. Data on demographic and socio-economic variables, and STH related knowledge, attitudes and practices, were obtained through a questionnaire. Stool samples were collected and assessed for STH egg presence using the Kato-Katz technique. Haemoglobin levels and height and weight of study participants were also determined. The generalized estimating equations approach was used to construct logistic regression models to assess STH-associated risk factors, and the association between any STH infection and anaemia, child stunting, wasting and being underweight. The trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12616000508471). FINDINGS: Among 1,689 schoolchildren, the prevalence of any STH was 23%. The prevalence of anaemia, stunting, being underweight and wasting was 13%, 20.2%, 19% and 9.5%, respectively. Age, socio-economic status, rural/urban classification of schools and knowledge of STH were significant risk factors for acquiring a STH infection. Moreover, infections with any STH were significantly associated with stunting (P = <0.001) and being underweight (P = <0.003), but not wasting (P = 0.375) or anaemia (P = 0.462) after controlling for confounding covariates. CONCLUSION: The study findings emphasise the need for sustainable deworming in tandem with other measures such as the provision of health education, improvements in sanitation and hygiene, and nutritional programs in order to control STH infections and improve morbidity outcomes in schoolchildren. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ACTRN12616000508471).