Parasite Intensity Research Articles

Relative efficacy of anti-Plasmodium vivax malaria combination drugs in preventing transmission to two major Anopheles mosquitos in the first few days of treatment

ObjectivesThe World Health Organization recommends three drug anti-malarial combinations: cloroquine+primaquine, artesiminin+primaquine, and cloroquine+tafenoquine. These combinations aim to eradicate Plasmodium by disrupting its life cycle within the human body. We evaluated the effect of these medications on the vectorial competence of two main vectors in the New World. Methods: We recruited patients diagnosed with malaria vivax from a primary care in Manaus, Amazonas. To determine how different treatments affected vectors, we collected blood samples prior treatment at the hospital and at six intervals over the next 68h at the patient's homes. These samples were used to infect Anopheles darlingi and Anopheles aquasalis. To assess the potential for Plasmodium transmission by bite to a new human host, we analyzed the infection intensity, infection rate, and presence of parasites in the salivary gland of the mosquitoes. Results: The results show the infection of the mosquitoes fed with the patient's bloods during the first days of treatment with all three drug combinations. However, the cloroquine+tafenoquine combination was the least effective while artesiminin+primaquine was the most effective. Conclusion: In the first few days of treatment, two main vectors continue to spread malaria vivax from patients, potentially contributing to the ongoing transmission in malaria-endemic regions.

Enhanced detection of Opisthorchis viverrini infection: A comparative evaluation of modified one-step FECT and conventional diagnostic methods in low-intensity setting

The formalin-ethyl acetate concentration technique (FECT) is one of the most sensitive diagnostic method not only for all helminths, but also for Opisthorchis viverrini infections in stool examinations. However, it remains a diagnostic problem for light infections. We modified the one-step FECT to determine the low-intensity of O. viverrini infection and compared with various conventional detection methods. The study utilized 160 egg-positive and 160 randomly negative stool samples for O. viverrini eggs by conventional FECT (cFECT) to compare the methods, including the simple smear, the Kato-Katz method, the two commercial stool examination kits, and the one-step FECT. Our results showed that the one-step FECT method had the highest sensitivity (95.6 %), followed by cFECT (87.9 %), the Kato-Katz (55.5 %), Aquisfek SF-FIX (48.3 %), simple smear (42.3 %), and Mini Parasep® SF (35.1 %). The ability of one-step FECT exhibited better ability to detect low parasite intensities compared to the cFECT (18 eggs per gram (e.p.g.) versus 34 e.p.g.) and the other conventional diagnostic methods. In addition, the investigation of O. viverrini infection in endemic regions in northeastern Thailand based on 3900 fecal samples revealed that the one-step FECT with an intensity of 66.8 e.p.g. (range 18–226) was significantly higher in sensitivity than cFECT, which had an intensity of 58.0 e.p.g. (range 34–214). Interestingly, fecal samples with less than 50 e.p.g. could not be detected by cFECT in 67 % of cases, and 69 out of 3900 samples were negative. In conclusion, one-step FECT improves the detection of low-intensity O. viverrini infection, which is suitable for parasites screening, especially for low-intensity infections in the community.

Identification and level of ectoparasite intensity in goldfish (Carassius auratus) at fishery product inspection and certification center fish seed center

Diseases and parasites that attack the fish body are often encountered in ornamental fish cultivation, so they can reduce the quality of the fish and cause fish death. Ectoparasites are parasites found outside the fish body. This study aimed to determine the type and intensity level of ectoparasite distribution in goldfish (Carassius auratus) cultivated at the Fishery Product Inspection and Certification Production Center (PPISHP) Fish Seed Center (BBI) Ciganjur, South Jakarta. A location survey and random sampling from three different rearing ponds were used. The goldfish samples obtained were 60 fish from three ponds in BBI Ciganjur. The results showed that the highest level of intensity of the Argulus sp. parasite was found in pond 2, the highest level of intensity of the Trichodina sp. parasite was found in pool 1, and the highest level of Lernea sp. parasite intensity was found in pools 1 and 3. The average infection level of each parasite showed that the intensity was relatively low.

How host ecology influences the parasite communities of three Australian flathead fishes, Platycephalus spp. (Scorpaeniformes: Platycephalidae)

This study investigated the role of host traits, habitat, and sampling season on the prevalence and intensity of parasites in three species of platycephalid fishes. Three host species sampled were dusky flathead (Platycephalus fuscus, n = 3), blue-spotted flathead (Platycephalus caeruleopunctatus, n = 38), and tiger flathead (Platycephalus richardsoni, n = 59). A total of 14 metazoan parasite species were collected over 15 months, between July 2020 and September 2021. The parasites found included a chondracanthid copepod, adult hemiuroidean trematodes, cestode plerocercoids, larval and adult acanthocephalans, larval and adult nematodes, and an unknown species of helminth. General linear models were used to assess the relationship between host traits and sampling season with parasite infection intensity. The infection intensity of an unidentified plerocercoid species in P. caeruleopunctatus was found to be significantly associated with both sampling season and the interaction of host mass with sex. In P. richardsoni the infection intensity of the acanthocephalan, Corynosoma sp. was found to correlate with sampling season. The highest richness of parasite taxa was recorded from P. richardsoni, which may be due to the wide depth range of P. richardsoni, coupled with its generalist diet.

Hemp regulates the fitness of corn earworm (Lepidoptera, Noctuidae) and its tachinid (Diptera) parasitoids.

Pest management on hemp is still in its infancy, and biological control options are limited. Helicoverpa zea (corn earworm) is one of the key pests of hemp cultivated outdoors, especially on cultivars grown for cannabinoids and grain. In a three-year study, we assessed the effect of diet on the performance of H. zea and its tachinid parasitoids. Parasitized (bearing fly eggs) and unparasitized (without eggs) H. zea larvae were fed on hemp flowers or an artificial diet. Five tachinid species parasitized H. zea larvae, but the most abundant species were Winthemia rufopicta (68.8%) and Lespesia aletiae (28.3%). Overall, 55.2% of H. zea larvae bearing tachinid eggs died, while the mortality of unparasitized larvae reached 24.7%. The success of tachinids increased by 2-fold when the host larvae were fed on an artificial diet. Our results demonstrated that high protein food (artificial diet), intensity of parasitism, and caterpillar size play a role in the fitness of both the herbivores (H. zea) and its tachinid parasitoids. These findings have important implications for understanding biological control mechanisms and open new insights into the impact of landscape variation on plant-herbivore-parasitoid interactions. This study contains supporting evidence that makes both Winthemia rufopicta and Lespesia aletiae excellent candidates for biological control programs against H. zea, a key pest of hemp in the United States.

Parasites disrupt a keystone mutualism that underpins the structure, functioning, and resilience of a coastal ecosystem

AbstractParasites can alter the traits or densities of mutualistic partners, potentially destabilizing mutualistic associations that underpin the structure, functioning, and stability of entire ecosystems. Despite the potentially wide‐ranging consequences of such disruptions, no studies have directly manipulated parasite prevalence and/or intensity in a mutualistic partner, nor quantified the resulting community‐level effects. Here, we investigated the effects of a common trematode parasite (Cercaria opaca) on the strength of a keystone facultative mutualism in western Atlantic salt marshes between the foundational marsh cordgrass, Spartina alterniflora, and the ribbed mussel, Geukensia demissa. Cordgrass increases mussel survivorship and growth through shading, while mussels enhance cordgrass growth by producing nutrient‐rich biodeposits. This mutualistic association also creates conditions that enhance biodiversity and ecosystem functioning, and mediates the ability of foundational plants to resist and recover from extreme drought. We used lab and field assays to show how increasing infection with trematode metacercariae negatively influenced mussel biodeposit production, as well as the strength of mussel shells and byssal attachments. By conducting a field manipulation using experimentally infected mussels, we demonstrated that the mutualistic benefits of mussels to cordgrass growth decreased with increasing trematode infection intensity—a pattern likely generated by reduced mussel biodeposition and enhanced mortality. Additionally, increasing parasite loads in mussels led to predictable decreases in the abundances of benthic invertebrates, as well as in key ecosystem characteristics and process rates (i.e., redox potential and sediment accretion). Finally, a survey of five North Carolina salt marshes demonstrated that infection with C. opaca was most common in mussels in areas experiencing cordgrass die‐off due to drought, and that infection intensity decreased with distance from die‐off areas. Because the mussel–cordgrass mutualism underpins marsh ecosystem resilience to drought‐associated die‐off, our results suggest that parasitism may depress recovery from these disturbances. Although this is the first experimental demonstration of parasites indirectly altering community structure and functioning by undermining an ecologically influential mutualism, this type of relationship could be common in nature, given that parasites frequently infect influential mutualists.

Do fungi look like macroparasites? Quantifying the patterns and mechanisms of aggregation for host-fungal parasite relationships.

Most hosts contain few parasites, whereas few hosts contain many. This pattern, known as aggregation, is well-documented in macroparasites where parasite intensity distribution among hosts affects host-parasite dynamics. Infection intensity also drives fungal disease dynamics, but we lack a basic understanding of host-fungal aggregation patterns, how they compare to macroparasites, and if they reflect biological processes. To address these gaps, we characterized aggregation of the fungal pathogen Batrachochytrium dendrobatidis (Bd) in amphibian hosts. Utilizing the slope of Taylor's Power Law, we found Bd intensity distributions were more aggregated than macroparasites, conforming closely to lognormal distributions. We observed that Bd aggregation patterns are strongly correlated with known biological processes operating in amphibian populations, such as epizoological phase-invasion, post-invasion, and enzootic-and intensity-dependent disease mortality. Using intensity-dependent mathematical models, we found evidence of evolution of host resistance based on aggregation shifts in systems persisting with Bd following disease-induced declines. Our results show that Bd aggregation is highly conserved across disparate systems and is distinct from aggregation patterns in macroparasites, and contains signatures of potential biological processes of amphibian-Bd systems. Our work lays a foundation to unite host-fungal dynamics under a common theoretical framework and inform future modeling approaches that may elucidate host-fungus interactions.

Bot fly parasitism in mantled howler monkeys (Alouatta palliata): General patterns and climate influences.

Parasitism is a strong selective pressure, and its study is crucial for predicting the persistence of host species. Mantled howler monkeys are infected by the larvae of the bot fly Cuterebra baeri. This parasitosis produces myiasis and may have negative impacts on host health, although systematic information on the dynamics of this host-parasite relationship is very limited. Currently, all available information on infection patterns of C. baeri comes from a single mantled howler monkey population (Barro Colorado Island, Panama). Therefore, in this study we describe temporal variation in infection patterns for a newly mantled howler monkey population and analyze the relationship between climate and infection likelihood. We assessed the presence of C. baeri nodules in 17 adult individuals in Los Tuxtlas for 10 months through direct observation and compiled data on ambient temperature and rainfall. Most subjects had nodules during the study and there were no differences between sexes in the number of nodules. Nodules were usually located in the neck. Prevalence and abundance of nodules peaked thrice during the study (February, April, and September), a pattern that was very similar to that of parasitism intensity (February, April, and August). Incidence closely tracked these peaks, increasing before and decreasing after them. The likelihood of nodule appearance increased when both mean and minimum temperature decreased in the 24-21 prior days to nodule appearance. It also increased with decreased rainfall in the 5-2 prior days to nodule appearance. Although only three of the eight analyzed climate variables had a significant effect on parasitosis, these results suggest that climate may affect pupal development and the access of larvae to hosts. Besides contributing data on C. baeri parasitism for a new mantled howler monkey population, our study provides novel information on the influence of environmental factors on the dynamics of host-parasite systems.

Microbiota and the volatile profile of avian nests are associated with each other and with the intensity of parasitism.

Bacteria have been suggested as being partially responsible for avian nest odours and, thus, volatiles from their metabolism could influence the intensity of selection pressures due to parasites detecting olfactory cues of their hosts. Here, we tested this hypothesis by exploring intraspecific and interspecific variability in microbial environments, volatile profiles and intensity of ectoparasitism by Carnus hemapterus in the nests of 10 avian species. As expected, we found that (i) alpha and beta diversity of microbial and volatile profiles were associated with each other. Moreover, (ii) alpha diversity of bacteria and volatiles of the nest environment, as well as some particular bacteria and volatiles, was associated with the intensity of parasitism at early and late stages of the nestling period. Finally, (iii) alpha diversity of the nest microbiota, as well as some particular bacteria and volatiles, was correlated with fledging success. When considering them together, the results support the expected links between the microbial environment and nest odours in different bird species, and between the microbial environment and both ectoparasitism intensity and fledging success. Relative abundances of particular volatiles and bacteria predicted ectoparasitism and/or fledging success. Future research should prioritise experimental approaches directed to determine the role of bacteria and volatiles in the outcomes of host-ectoparasite interactions.

Haemosporidian intensity and nestlings' life-history along an urban-to-rural gradient

Urban areas, i.e. dense housing and reduced green spaces, can significantly impact avian health, through altering land use and increasing biotic and abiotic stress. This study assessed the association of urbanization on haemosporidian infections, vectors, immune response, and body condition in Parus major nestlings, across four classes of urbanization along an urban-to-rural gradient in Vienna, Austria. Contrary to our expectations, vector abundance remained consistent across the gradient, while an increase in leukocyte count is positively associated with total parasite intensity. We found that nestlings in more urbanized areas exhibited higher parasite intensity and altered immune response, as evidenced by variations in the heterophil to lymphocyte ratio and leukocyte counts. Culicidae female vectors were associated with nestlings’ total parasites, scaled mass index, and industrial units. Nestlings in highly developed areas had higher infection rates than those in forests, suggesting increased exposure to infections. However, there was no clear relationship between total female vectors and total parasites. The level of urbanization negatively affected nestling body condition, with a decrease in fat deposits from forested to highly urbanized areas. Our findings highlight the complex interplay between urbanization, vector-borne parasite transmission, and host immune response, emphasizing the need for comprehensive urban planning to improve wildlife health and guarantee ecosystem functioning. Understanding how urbanization affects bird immunity and parasite infections is critical for adapting urban landscapes for wildlife health and ecosystem integrity.

Environmental conditions influence host-parasite interactions and host fitness in a migratory passerine.

The study of host-parasite co-evolution is a central topic in evolutionary ecology. However, research is still fragmented and the extent to which parasites influence host life history is debated. One reason for this incomplete picture is the frequent omission of environmental conditions in studies analyzing host-parasite dynamics, which may influence the exposure to or effects of parasitism. To contribute to elucidating the largely unresolved question of how environmental conditions are related to the prevalence and intensity of infestation and their impact on hosts, we took advantage of 25 years of monitoring of a breeding population of pied flycatchers, Ficedula hypoleuca, in a Mediterranean area of central Spain. We investigated the influence of temperature and precipitation during the nestling stage at a local scale on the intensity of blowfly (Protocalliphora azurea) parasitism during the nestling stage. In addition, we explored the mediating effect of extrinsic and intrinsic factors and blowfly parasitism on breeding success (production of fledglings) and offspring quality (nestling mass on day 13). The prevalence and intensity of blowfly parasitism were associated with different intrinsic (host breeding date, brood size) and extrinsic (breeding habitat, mean temperature) factors. Specifically, higher average temperatures during the nestling phase were associated with lower intensities of parasitism, which may be explained by changes in blowflies' activity or larval developmental success. In contrast, no relationship was found between the prevalence of parasitism and any of the environmental variables evaluated. Hosts that experienced high parasitism intensities in their broods produced more fledglings as temperature increased, suggesting that physiological responses to severe parasitism during nestling development might be enhanced in warmer conditions. The weight of fledglings was, however, unrelated to the interactive effect of parasitism intensity and environmental conditions. Overall, our results highlight the temperature dependence of parasite-host interactions and the importance of considering multiple fitness indicators and climate-mediated effects to understand their complex implications for avian fitness and population dynamics.

First reports of urogenital schistosomiasis in the Ndikiniméki health district, Center Cameroon

ObjectivesSchistosomiasis is still a public health problem in sub-Saharan Africa, particularly in Cameroon. In this context, a cross-sectional study was carried out from June 2023 to July 2023 in the Ndikiniméki subdivision, with the aim of knowing the status of this locality in relation to Schistosoma haematobium infection. MethodsA parasitologic analysis of S. haematobium eggs was carried out on urine samples using the sedimentation technique. ResultsA total of 402 urine samples were collected from households. The age range of participants was 1-96 years, with the most signified age group being 1-9 years. Women were the most represented, with a proportion of 56.47%. Of the 402 people examined, 18 (4.45%) were affected, with an average intensity of 54.43 ± 85.30 eggs/10 mL urine. Women were the most affected, with a prevalence and average parasite intensity of 3.73% and 53.10 ± 131.27 eggs/10 mL of urine. The most affected age group was 10-19 years, with a prevalence and intensity of 4.60% and 49.49 ± 67.00 eggs per 10 mL of urine, respectively. Of those infected, 72.22% were lightly infected and 27.28% were heavily infected. ConclusionsThis study indicates that this locality is a risk area for urinary schistosomiasis despite its low prevalence.

Prevalence of Gastrointestinal Parasites of African Catfish (Clarias gariepinus) from River Nasarawa, Nasarawa State, Nigeria

Fish and fish products are significant sources of nutrients for humans. Parasites of fish are of concern since they often produce a weakening of the host’s immunity thereby increasing susceptibility to secondary infections. This study was conducted with aimed to examine the prevalence of gastrointestinal parasites infecting fish. Field study was conducted during the period from September to November 2022. A total of 200 fish samples (Clarias gariepinus) were examined for the presence of gastrointestinal parasites. Result show that, total number of fishes infected 60(30.0%) out of which 26(26.26%) males and 34(33.66) female. Two helminths one each from Cestode and Nematode were isolated from the infected fishes. The Cestode and its prevalence were Diphylobothrium latum (5%) and nematode Procamallanus spp. (3.33%). The protozoa recovered included: Hexamita spp., Protoopalina spp. and Microsporidia with 60.00%, 23.33% and 18.34% respectively. The majority of the parasites were found in the intestine. Fish specimens that were lighter in weight 10 -200g had less infection (12.5%) but those found with parasites weighed between 201-400g (42%). There was no significant difference (P>0.05) in the infection between male and female Clarias gariepinus and with age on the prevalence and intensity of the gastrointestinal parasite. Wild fish (Clarias gariepinus) in River Nasarawa have a high prevalence of intestinal parasites, therefore it is recommended to avoid open defecation that finally is washed down to rivers and streams hence affecting the aquatic organisms and to properly cook wild fish obtained from River Nasarawa before consumption for safety.

Prevalensi, Intensitas, dan Dominansi Parasit pada Ikan Manggabai (Glossogobius giuris) di Danau Limboto Provinsi Gorontalo

This study aimed to identify the different types of parasites infecting manggabai fish (Glossogobius giurus) in Lake Limboto, in addition to analyzing the intensity, prevalence, and dominance of parasites in the population. Twenty manggabai fish samples were collected from three different locations in Lake Limboto, namely Dembe 1, Tabmela, and Hutuo. The parasite examination process was carried out at the Zoology Laboratory of the Biology Department of Gorontalo State University, focusing on organs such as skin, gills, fins, and digestive organs. The method applied was the native method, which involves direct observation. The identification results showed the presence of three types of parasites in manggabai fish, namely Gyrodactylus sp., Camallanus sp., and Ligula intestinalis. The highest prevalence was recorded for Gyrodactylus sp. at 65%, indicating a significant spread of parasites in the fish population. The parasite intensity of Camallanus sp. from Hutuo at 7. The parasite Ligula intestinalis showed the highest dominance with a value of 44%. Meanwhile, the highest prevalence and intensity values were placed in the frequent and mild categories.

Prevailing parasitic diseases affecting Oreochromis aureus in Lake Burullus.

Lake Burullus is an important source of fish production in Egypt; it produces 20.5% of the Egyptian fisheries' production. There is intense controversy about the heavy metal pollution in Burullus water and its effects on fish health and safety for human consumption. Heavy metals represent a major concern for aquatic life and could negatively affect fish health. Agricultural and industrial water drainage represents a considerable part of the lake water supply. The present work was conducted to determine heavy metal concentrations in lake water and blue tilapia Oreochromis aureus musculature. Water samples were collected from six locations to determine cadmium, copper, lead, zinc and iron. Sixty O. aureus fish samples were also collected from the same sampling points to assess the prevalent parasites infesting fish and to determine the heavy metal (Cd, Cu, Pb, Zn and Fe) concentrations in fish musculature then study the relationship between heavy metals concentration and prevailing fish parasites. Results indicated that 53.34% of the examined fish were infested with encysted metacercaria. Centrocestus formosanus, Prohemistomum vivax, and Euclinostomum heterostomum were retrieved from gills, musculature, hepatopancreas and the posterior kidney. The parasitic intensity in fish tissues was between 1 and 9 cystg-1. Centrocestus formosanus was identified using the polymerase chain reaction in the gill tissues of 16 fish. The gill parasitic copepod Lamproglena monodi was identified in one fish. Degenerative changes such as thickening, corrugation, and destruction of gill filament are the most dominant pathological changes in infested fish gills. Heavy metal concentrations in water samples were at normal levels, except for copper and iron in the southern part of the lake. All heavy metals in fish musculature were below the permissible limits. The parasitic infestation was more dominant in the northern part of the lake than in the southern region; this could be due to elevated copper concentration in the southern part of the lake that could negatively affect the survival of the first intermediate host and parasite cercaria. In conclusion, captured fish from Lake Burullus were safe for human consumption, and heavy metal pollution in lake water does not represent a severe risk.

Malaria and Typhoid Co-Infection among Children under 5 Years of Age at Chukwuemeka Odumegwu Ojukwu University Teaching Hospital, Awka, Anambra State, Nigeria

This study sheds light on the prevalence of malaria and typhoid in children below the age of five in a hospital in Nigeria. This study aimed to determine the presence of malaria, typhoid and malaria-typhoid co-infection in children less than five years of age. In this community-based descriptive, quantitative and cross-sectional hospital-based survey, the blood samples of 125 children between 0 to less than 5 years (68 males and 57 females) were examined for the presence of malaria parasites and typhoid infection. Blood samples were collected using venepuncture. The malaria parasitaemia was detected using malaria microscopy on a thick blood film. Typhoid fever infection was detected using the Widal Agglutination Test. The chi-square test was used to compare the prevalence of malaria, typhoid fever and malaria/typhoid co-infections between male and female infected and uninfected participants and between children below 1 year and those 1 year and above. P-values less than 0.05 were considered significant. A prevalence of 47.2%, 32% and 16% were recorded for malaria, typhoid and malaria/typhoid co-infection respectively. A mean malaria parasite intensity of 56.8475 (±3.30177) was recorded. There was no significant difference between the prevalence of malaria, typhoid and malaria/typhoid co-infection between the genders and age groups. Also, there was no significant difference between the mean PCV of the infected (33.1610 (±0.80748) and uninfected (34.6667 (0.48441) (P> 0.05). These results underscore the importance of continued efforts to combat these diseases and improve the health and well-being of children in the region.

High parasite prevalence in an ecosystem engineer correlated with both local- and landscape-level factors.

Spatial variation in parasitic infection may have many physical and biological drivers. Uncovering these drivers may be especially important for parasites of ecosystem engineers because the engineers are foundational to their communities. Oysters are an important coastal ecosystem engineer that have declined drastically worldwide, in part due to enhanced cases of lethal oyster diseases, such as Dermo and MSX, caused by the protozoan parasites Perkinsus marinus and Haplosporidium nelsoni, respectively. Besides water quality and hydrodynamics, there is little information on how other variables influence the prevalence and intensity of these pathogens in oysters across a regional scale. To examine drivers of spatial variation in these oyster parasites-including host size, local reef properties, and landscape properties-we sampled 24 reefs systematically spread along the coast of Georgia, USA. Across sites, we found universally high prevalence of oysters with at least one of these parasites (91.02% ± 8.89, mean ± SD). Not only are high levels of parasite prevalence potentially problematic for a pivotal ecosystem engineer, but also low spatial variability may limit the explanatory power of variables across a regional scale. Our statistical models explained between 18 and 42% of the variation in spatial patterns of prevalence and intensity of these microparasites. Interestingly, landscape context was a positive predictor of P. marinus, but a negative predictor of H. nelsoni. Overall, our findings suggest that factors driving parasite prevalence and intensity operate across multiple spatial scales, and the same factor can both facilitate and hinder different parasites within the same host species.

Influence of Anthelmintic Treatment on Immune Response and Oxidative Stress in Cattle Vaccinated against Lumpy Skin Disease

Background: Vaccination and deworming are routine programs in cattle health management. However, the anthelmintic’s effectiveness on the immune response in vaccinated cattle is limited. Therefore, this study investigated whether anthelmintic administration affects the oxidative stress and immunity induced by vaccination against lumpy skin disease (LSD) in cattle. Methods: Thirty-seven Thai beef cattle were divided into two groups. Group 1) 19 cattle were vaccinated against LSD with a Neethling LSD virus (LSDV) vaccine as the control group and Group 2) 18 cattle were vaccinated against LSD with a Neethling LSDV vaccine and received albendazole treatment. Then, the intensity of gastrointestinal parasite infestation, level of malondialdehyde, inflammatory cytokines and antibody titer to LSDV were investigated in both groups on day 30 of the experimental period. Result: The results showed that the types and intensity of gastrointestinal parasites were decreased in the anthelmintic-treated group. There were no significant differences in the levels of malondialdehyde, IFN-γ, TNF-α and LSD-specific antibody titers between the control and the anthelmintic treatment group (P greater than 0.05), while the expression level of IL-4 in the anthelmintic treatment group was significantly lower than in the control group (P less than 0.05). Our study indicated that albendazole treatment did not affect oxidative stress and innate and adaptive immunity against LSDV. Moreover, single-dose albendazole therapy led to a reduction in the expression level of IL-4, which is involved in defense against parasites.

Volatiles of symbiotic bacterial origin explain ectoparasitism and fledging success of hoopoes

BackgroundSome parasites use olfactory cues to detect their hosts and, since bacterial symbionts are partially responsible for animal odours, they could influence host parasitism. By autoclaving nest materials of hoopoe (Upupa epops) nests before reproduction started, we explored the hypothetical links between host-associated bacteria, volatiles and parasitism. During the nestling stage, we (i) estimated the level of ectoparasitism by chewing lice (Suborder Mallophaga) in adult hoopoe females and by Carnus haemapterus flies in nestlings, and (ii) characterized microbial communities and volatile profiles of nest environments (nest material and nest cavity, respectively) and uropygial secretions.ResultsExperimental nests had less diverse bacterial communities and more diverse volatile profiles than control nests, while occupants experienced lower intensity of parasitism in experimental than in control nests. The experiment also affected beta diversity of the microbial communities of nest material and of the volatiles of the nestling uropygial secretions. Moreover, microbial communities of uropygial secretions and of nest materials covaried with their volatile profiles, while the volatile profile of the bird secretions explained nest volatile profile. Finally, a subset of the volatiles and bacteria detected in the nest material and uropygial secretions were associated with the ectoparasitism intensity of both adult females and nestlings, and with fledging success.ConclusionsThese results show that a component of animal odours is linked with the microbial communities of the host and its reproductive environment, and emphasize that the associations between bacteria, ectoparasitism and reproductive success are partially mediated by volatiles of bacterial origin. Future work should focus on mechanisms underlying the detected patterns.

Variation in prevalence and intensity of macroparasites in moose and their interactions with winter tick load in eastern Canada

Wild animals are infected with a large diversity and abundance of parasites that can affect their behavior, growth, body condition, and ultimately their survival. Although the adverse effects of parasites and the mechanisms involved in the interactions between a host and its parasites are generally well studied, much less is known about the additive or synergistic effects of multiple parasite species on a host. Moose populations in eastern Canada are infected by several species of endoparasites. In the last decades, the intensity of infestations by winter ticks, an ectoparasite, on moose have increased as a result of increased moose densities and favorable weather conditions that benefit winter tick survival. We aimed to document the diversity, intensity, prevalence, and distribution of different parasite species of moose in southern Quebec, Canada. We then evaluated the potential interaction between winter tick and endoparasites of moose, and we evaluated the effect of the simultaneous presence of ticks and endoparasites on moose body condition. To do so, we collected organs to identify and count endoparasite species, estimate winter tick abundance, and measure subcutaneous fat thickness from 174 hunted moose in fall 2019 in 8 regions of Quebec. Our results showed that the prevalence and intensity of winter tick and gastrointestinal parasites differed among regions, as well as the prevalence of the heart parasite Taenia krabbei and the intensity of lung parasite Echinoccocus granulosus. Moose body condition, however, was not influenced by the simultaneous presence of winter tick and endoparasites. The documentation of the interactive effects of multiple parasite species on a host is fundamental given that future environmental conditions in temperate climate will favor the reproduction, development, and survival of several parasite species, which could affect parasite diversity and abundance in the environment and modify host–parasite dynamics.