Seroprevalence of Toxoplasma gondii and Neospora spp. Infections in Arab Horses, Southwest of Iran

Seroprevalence of Toxoplasma gondii and Neospora spp. in horse population of Tehran, Iran

Neospora spp. and Toxoplasma gondii are two closely related protozoan parasites that are widely distributed throughout the world. Horses can act as intermediate hosts for both parasites and can acquire disease. Blood samples were taken from 487 clinically healthy horses from 17 different mechanized stables in Tehran, the capital of Iran, during September and November of 2022. IFAT and ELISA were employed to detect antibodies directed against Neospora spp. and T. gondii. The anti-N. caninum antibodies were detected in 52 of the horses (10.67%) based on IFAT and in 86 of the 487 horses (17.65%) based on the ELISA test. Also, antibodies against T. gondii were detected in 41 horses (8.42%) based on IFAT and in 63 of 487 horses (12.94%) based on the ELISA test. Also, in 6 of the horses (1.23%) based on IFAT and in 13 of the 487 horses (2.67%) based on the ELISA test, double positivity suggested co-infection with both parasites. Gender, age groups, and the presence of dogs for neosporosis, and age groups and the presence of cats for toxoplasmosis, could be considered factors having an influence on the seroprevalences (P < 0.05). The results proved the importance of the urgent implementation of stringent regulatory measures to prevent and control the spread of these parasites.

Seroprevalence and Risk Factors for Toxoplasma gondii Infection in Horses

BACKGROUND

Toxoplasma gondii is classified as intracellular protozoa and is one of the major zoonotic parasites. Most warm-blooded intermediate hosts, including humans, are commonly infected by this parasite. The epidemiology of T. gondii infection in Egyptian horses is currently poorly understood.

METHODS

420 blood samples were randomly collected from horses raised in four governorates in Northern Egypt (110 each from Giza and Kafr El Sheikh, and 100 each from Qalyubia and Gharbia) to investigate the existence of antibodies against T. gondii using a commercial ELISA kit, and to ascertain the risk factors for the infection.

RESULTS

the antibodies for T. gondii were found in 16.2% (68/420) of the examined horses, with no significant differences among the four studied governorates. The highest prevalence rate was observed in Giza. The results revealed that sex, breed, age, and contact with domestic ruminants or cats were recognized as potential risk factors. The high prevalence rate was found in mixed breed horses (OR = 2.63, 95% CI: 0.95-7.26), mares (OR = 2.35, 95% CI: 1.31-4.19), and horses aged over 10 years (OR = 2.78, 95% CI: 1.30-3.44). Moreover, the likelihood of seropositivity for T. gondii infection was higher in horses raised in environments with cats (OR = 1.97, 95% CI: 1.13-3.44, p = 0.017) or domestic ruminants (OR = 2.16, 1.21-3.86, p = 0.010). This report confirms that horses in Northern Egypt are exposed to T. gondii and thus raises the possibility that people and other animals could contract the disease.

CONCLUSIONS

routine examination and management of T. gondii infection in horses in these governorates is advised.

Neospora caninum, a cause of abortion in donkeys (Equus asinus) in Iran

Neospora caninum is an Apicomplexan parasite that can cause enormous economic losses due to abortions in cattle. The present study investigated the role of Neospora spp. infection in equine abortion in Iranian donkeys using molecular and phylogenetic analyses. Twenty-nine-aborted fetuses and 29 blood samples from their dams were collected from six different regions in the West and Northwest of Iran. They were tested for N. caninum by PCR at the Nc5 locus, followed by sequencing of five of the PCR products. The overall molecular prevalence was 34.5% in blood samples and the prevalence by DNA detection in the aborted fetuses was 13.8%. Evidence of transplacental transmission from positive jennies to their fetuses was detected in 40% of aborting jennies. Comparison of the five partial Nc5 sequences (227 bp length) exhibited 98-100% similarity with N. caninum GenBank sequences. This is the first molecular study and genetic characterization of N. caninum in Iranian donkeys suggests that N. caninum may be a significant cause of abortion in donkeys.

Prevalence of endo- and ecto-parasites of equines in Iran: A systematic review

Equines are subject to infection with many parasites, which threaten their health. In the present study, we systematically reviewed existing literature on the prevalence of endo- and ectoparasites of equines in Iran. Major electronic databases, including PubMed, PubMed Central, Google Scholar, Science Direct and Scientific Information Database (SID), were searched (Last updated 11/05/2018) for relevant literature of parasites that have been identified from equines in Iran. Of the 1809 titles produced by bibliographic search, 38 were included in the review. Twenty-seven of the studies were on horses, six on donkeys, three on both horses and donkeys, and one study was on both horses and mules. Furthermore, 24 of the studies reported infections caused by protozoa, thirteen by helminths, two by ectoparasites, and one by both protozoa and helminths. The overall pooled prevalence of parasitic infection was 28.8% (95%CI: 22.9-35.7, I²  = 93.4%). Helminths were the most prevalent parasites 46.7% (95% CI: 24.1-70.7, I²  = 96.0%). Furthermore, donkeys were the most affected equine, with a prevalence of 70.7% (95% CI: 53.2-83.7, I²  = 92.5%). The protozoa frequently reported included nine species belonging to the genera: Neospora, Toxoplasma, Theileria, Babesia and Eimeria. Also, the helminths frequently reported included 21 species belonging to the genera: Strongylus, Dicrocoelium, Oxyuris, Habronema, Echinococcus, Dictyocaulus, Cyathostomum, Probstmayria, Anoplocephala, Setaria and Fasciola. Ticks were the only ectoparasites frequently reported. Parasitic fly species of the genera Gasterophilus were also reported. The study-level risk of bias was likely to be high because of differences in study design. Parasitic infections of equines in Iran are frequent and caused by a diversity of parasites, which threatens the health and well-being of these animals. Further research is needed in the area to identify the risk factors of infection for effective control of the parasites.

Parasitic diseases of equids in Iran (1931-2020): a literature review

Parasitic infections can cause many respiratory, digestive and other diseases and contribute to some performance conditions in equids. However, knowledge on the biodiversity of parasites of equids in Iran is still limited. The present review covers all the information about parasitic diseases of horses, donkeys, mules and wild asses in Iran published as articles in Iranian and international journals, dissertations and congress papers from 1931 to July 2020. Parasites so far described in Iranian equids include species of 9 genera of the Protozoa (Trypanosoma, Giardia, Eimeria, Klossiella, Cryptosporidium, Toxoplasma, Neospora, Theileria and Babesia), 50 helminth species from the digestive system (i.e., 2 trematodes, 3 cestodes and 37 nematodes) and from other organs (i.e., Schistosoma turkestanica, Echinococcus granulosus, Dictyocaulus arnfieldi, Parafilaria multipapillosa, Setaria equina and 3 Onchocerca spp.). Furthermore, 16 species of hard ticks, 3 mite species causing mange, 2 lice species, and larvae of 4 Gastrophilus species and Hippobosca equina have been reported from equids in Iran. Archeoparasitological findings in coprolites of equids include Fasciola hepatica, Oxyuris equi, Anoplocephala spp. and intestinal strongyles. Parasitic diseases are important issues in terms of animal welfare, economics and public health; however, parasites and parasitic diseases of equines have not received adequate attention compared with ruminants and camels in Iran. The present review highlights the knowledge gaps related to equines about the presence, species, genotypes and subtypes of Neospora hughesi, Sarcocystis spp., Trichinella spp., Cryptosporidium spp., Giardia duodenalis, Blastocystis and microsporidia. Identification of ticks vectoring pathogenic parasites, bacteria and viruses has received little attention, too. The efficacy of common horse wormers also needs to be evaluated systematically.

Global seroprevalence of Neospora spp. in horses and donkeys: A systematic review and meta-analysis

Neospora infections due to Neospora caninum and N. hughesi are prevalent among equids of the world. The disease may affect reproductive and neurological consequences. The present systematic review and meta-analysis was performed to evaluate the global Neospora seroprevalence among horses and donkeys. A number of 57 out of 1575 total retrieved studies were included by searching the PubMed, Scopus, Science Direct, Web of Science and ProQuest. A total of 25,783 horses and 4377 donkeys were examined serologically, yielding a weighted seroprevalence of 13.46 % (95 % CI: 10.26 %-17.42 %) globally. Subgroup analysis revealed that there were statistically significant differences in the overall prevalence of Neospora spp. in the examined animals according to year, continent, WHO region, country, host, and diagnostic method. Age and sex in horses as well as sex in donkeys were significantly associated with the Neospora seroprevalence (P < 0.001). Our findings showed a relatively high exposure to Neospora spp. in horses and donkeys worldwide. Considering the possible economic impact, as well as the importance in animal health, more studies are needed to clarify the species causing equine neosporosis, correlate serological findings with clinical outcomes and assess the risk factors, in order to define adequate prevention and control strategies.

Neospora caninum infection in Iran (2004-2020): A review

Knowledge on neosporosis and associated risk factors in different species of animals are so important for designing the control programs and reduce the economic losses globally. This literature review targeted for evaluating the infection rate of Neospora caninum in animals in Iran. Until April 2020, all of published documents in the main English and Persian-language databases were searched. A total number of 110 documents (English = 85 and Persian = 25) were extracted. Most of reports were sero-epidemiological studies using ELISA in Iranian cattle population. The range of Neospora infection was 3.8–76.2% in cattle, 0–54.6% in dogs, 0.9–9.9% in sheep, 6.2% in goats, 19.2–55.9% in buffaloes, 20–42.2% in horses, 52% in donkeys, 3.2–27% in camels, 14% and 19% in cats, and 0–20.4% in rodents. This rate in birds was 17.3% in chicken, 9.8% and 30.4% in pigeons, 2.8% and 3.7% in sparrows, and 9.9% in hooded crows. This is a comprehensive literature review on Neospora infection in Iran at the first time. The infection of N. caninum is widespread in Iran especially in dogs and cattle population. This review can provide baseline information for future research. Study on other hosts especially on wild and exotic animals is recommended for exact estimate of neosporosis in Iran. Investigations into molecular diagnosis and genotyping of N. caninum strains are also needed; this will be helpful for developing vaccines and finding the connection among wild and domestic cycles of disease. Education on the risk factors associated with N. caninum infection for is suggested farmers and rural public.

Toxoplasma gondii infection and toxoplasmosis in farm animals: Risk factors and economic impact

The protozoan parasite Toxoplasma gondii is a zoonotic parasite that can be transmitted from animals to humans. Felids, including domestic cats, are definitive hosts that can shed oocysts with their feces. In addition to infections that occur by accidental oral uptake of food or water contaminated with oocysts, it is assumed that a large proportion of affected humans may have become infected by consuming meat or other animal products that contained infective parasitic stages of T. gondii. Since farm animals represent a direct source of infection for humans, but also a possible reservoir for the parasite, it is important to control T. gondii infections in livestock. Moreover, T. gondii may also be pathogenic to livestock where it could be responsible for considerable economic losses in some regions and particular farming systems, e.g. in areas where the small ruminant industry is relevant. This review aims to summarize actual knowledge on the prevalence and effects of infections with T. gondii in the most important livestock species and on the effects of toxoplasmosis on livestock. It also provides an overview on potential risk factors favoring infections of livestock with T. gondii. Knowledge on potential risk factors is prerequisite to implement effective biosecurity measures on farms to prevent T. gondii infections. Risk factors identified by many studies are cat-related, but also those associated with a potential contamination of fodder or water, and with access to a potentially contaminated environment. Published information on the costs T. gondii infections cause in livestock production, is scarce. The most recent peer reviewed reports from Great Britain and Uruguay suggest annual cost of about 5-15 million US $ per country. Since these estimates are outdated, future studies are needed to estimate the present costs due to toxoplasmosis in livestock. Further, the fact that T. gondii infections in livestock may affect human health needs to be considered and the respective costs should also be estimated, but this is beyond the scope of this article.

Soroprevalência de Toxoplasma gondii em equídeos do Nordeste do Brasil

RESUMO: Este estudo teve como objetivo determinar a soroprevalência da toxoplasmose em equídeos mantidos em diferentes formas de manejo no estado de Pernambuco. Para tanto, um total de 400 amostras de soro sanguíneo de equídeos clinicamente saudáveis foram analisados através do teste de aglutinação modificado (MAT) considerando-se cut-off de 1:25. Dados referentes às características dos animais e dos rebanhos, sistema de criação, presença de outros animais, idade, sexo, raça, aptidão, condição física foram coletados por meio de questionários investigativos. Anticorpos IgG anti-Toxoplasma gondii foram detectados em 12,5% (50/400) dos animais analisados. Dos 12 municípios estudados, houve positividade em 91,67% (11/12) com variação entre 4,4% e 33,3%. Quando avaliados os fatores de risco, apenas o fator mesorregião (p=0,029) apresentou associação com a infecção, particularmente Zona da Mata (OR=3), seguida de Região Metropolitana do Recife (OR=2,2), Agreste (OR=1,7) e Sertão (OR=1). Os resultados revelam a presença do parasito na área estudada, o que pode representar um elo na cadeia de transmissão da toxoplasmose a qual tem repercussão em saúde pública tendo em vista que o Brasil é o oitavo maior exportador de carne equina do mundo.