Toxoplasmainfection and milk consumption: Meta-analysis of assumptions and evidences

Serological survey of immunoglobulin G from Toxoplasma gondii infection in dairy goats in East Java, Indonesia

Background and Aim

Toxoplasma gondii infection is a significant issue of veterinary public health because it is potentially transmitted through goat milk. Therefore, the use of control measures and routine monitoring of toxoplasmosis in dairy goats is necessary. Serological analysis using antibodies can detect T. gondii infection. This study aimed to conduct an epidemiological study of T. gondii in dairy goats using antibody detection and risk factor identification.

Materials and Methods

This was a cross-sectional study. We performed a serological analysis of T. gondii infection in dairy goats to evaluate the prevalence of toxoplasmosis. Random sampling was performed, including 132 lactating dairy goats. Toxoplasma-modified agglutination test was used as a serological test for immunoglobulin G with a sensitivity of 98.55%, specificity of 86.21%, and accuracy of 94.9%. A structured questionnaire was used to collect risk factor data, which were analyzed using the Chi-square and Fisher's exact tests. The statistical package for the social sciences v. 21 was used for statistical analyses.

Results

The seroprevalence of T. gondii in Malang and Lumajang Regency was 100% and 90.7%, respectively. A significant difference in prevalence of T. gondii was observed between the two districts. Livestock management practices that significantly influenced T. gondii seroprevalence included water sources (p < 0.05; relative risk [RR] = 1.151; 95% confidence interval [CI]: 1.044-1.269). Farmers' characteristics that significantly influenced T. gondii seroprevalence included education (p < 0.05; RR = 1.125; 95% CI: 1.037-1.221), main occupation (p < 0.05; RR = 1.118; 95% CI: 1.035-1.207), and position in the organization of dairy goats farmers (p < 0.05; RR = 1.141; 95% CI: 1.022-1.274).

Conclusion

In East Java, the prevalence of T. gondii in dairy goats is high. This study provides detailed information regarding risk factors associated with T. gondii seroprevalence in dairy goats in East Java, Indonesia.

Detection of Toxoplasma gondii DNA in milk of dairy cows from southern Brazil

Consumption of unpasteurized cow's milk may be a transmission route for some pathogenic microorganisms, but there is little information about the risk of Toxoplasma gondii infection. Blood and milk samples were collected in a paired and random fashion from 106 dairy cows and bulk-tank milk samples were also collected from each of the six farms, in southern Brazil. Serum anti-T.gondii antibodies (IgG) were detected by an indirect fluorescent antibody test (IFAT) with a cutoff point of 1:64. Nested PCR targeting the ITS1 was performed on milk samples to detect the Sarcocystidae family, confirmed to be T.gondii by Sanger sequencing. The occurrence of anti-T.gondii antibodies in the herds was 14.1%, (15/106) with seropositive cows in all herds. Antibody titers in positive samples ranged from 64 to 128. T.gondii DNA was detected in 2.8% (03/106) of the milk samples. The ITS1 sequences generated in this study were ON809793 - ON809794 and the sequencing revealed 98-100% identity with T. gondii DNA sequences deposited in GenBank. All cows PCR positive for T.gondii in milk were negative for IgG antibodies in serum, suggesting that naturally infected cows may shed T. gondii in milk in the acute phase of infection. The results of this study demonstrate that T. gondii DNA may be detected in raw cow's milk, so the potential risks of lactogenic infection should be considered. The presence of T. gondii DNA in milk does not confirm that the protozoa are viable and infective, and further investigations into the role of cow's milk in the epidemiology of toxoplasmosis are needed.

Seroprevalencia y factores de riesgo asociados a toxoplasmosis gestacional en el Nororiente Colombiano

Highlights: La toxoplasmosis gestacional podría constituir una grave problemática en ascenso en la población atendida en zona fronteriza nororiental de Colombia. La incrementada reactividad IgM específica a T.gondii en mujeres gestantes representa una alarma para la generación de estrategias de impacto en la prevención de esta problemática, como población priorizada. La seronegatividad frente a T.gondii, aún predominante en población gestante evaluada en región nororiental de Colombia, constituye un factor de riesgo relevante de toxoplasmosis gestacional, reflejado en alta susceptibilidad. La considerable exposición a factores de riesgo de toxoplasmosis en el embarazo implica una clara oportunidad de mejora de la calidad del control prenatal, mediante atención integral. Introducción:La toxoplasmosis es una zoonosis prevalente en un tercio de la población mundial, que afecta negativamente la salud materno-fetal causando daños de grado variable al feto. Objetivo: Se propuso evaluar el estado serológico IgG e IgM anti-Toxoplasma gondii y factores de riesgo relacionados, en mujeres gestantes de primer trimestre en Cúcuta, Colombia, en el año 2018. Materiales y métodos: Estudio transversal y correlacional en 111 mujeres participando voluntariamente, a quienes se testeó para IgM e IgG específicas por inmunoensayo LIA. Resultados: Se halló 19,8% y 35,1% de seropositividad total para IgM e IgG, respectivamente, 11,7% lo fue únicamente para IgM y 53,2% corresponde a la frecuencia de seronegatividad global para T.gondii; Se identificaron factores de riesgo (IC=95%) como consumo de carne mal cocida (54,1% de los casos, OR=1,8, p=0,120), de agua del grifo (48,6%, OR=1,4, p=0,421), de leche cruda de cabra o de vaca (39,6%, OR=0,78, p=0,553), además de convivencia con gatos (23,4%), éste último asociado significativamente a seropositividad al parásito (OR=2,8, p=0,025). Discusión y Conclusiones: Nuestros hallazgos revelan un posible riesgo de primo-infección en más de la mitad de la población gestante dada su seronegatividad frente al parásito, pero también una frecuencia considerable de casos con sospecha de infección muy reciente, lo que además de asociarse a un factor de riesgo previamente reconocido, deja entrever otros aspectos de riesgo en torno a la alimentación que deben impactarse mediante estrategias de prevención durante el control prenatal, sugiriendo la necesidad de fortalecer la vigilancia en torno al evento. Como citar este artículo: Cárdenas Sierra Denny Miley, Domínguez Julio Camila, Blanco Oliveros María Ximena, Soto Javier Andrés, Tórres Morales Elizabeth. Seroprevalencia y factores de riesgo asociados a toxoplasmosis gestacional en el Nororiente Colombiano. Revista Cuidarte. 2023;14(1):e2287. http://dx.doi.org/10.15649/cuidarte.2287

Use of PCR to determine Toxoplasma gondii in milk samples from camels (Camelus dromedarius), cattle (Bos taurus) and buffalos (Bubalus bubalis) in East Azarbaijan province, Iran

BACKGROUND

Toxoplasmosis as a zoonotic condition is developed by an intracellular protozoan parasite Toxoplasma gondii from the Apicomplexa phylum, which imposes economic losses on herds of animals and severe complications in immunocompromised people and pregnant women. This infectious disease can be transmitted to human beings from the contaminated unpasteurized milk, uncooked meat, water and food contaminated with sporulated oocysts and transplacental transmission.

OBJECTIVES

This study amid to determine T. gondii DNA in camel, buffalo and cow milks in using the PCR method based on the B1 gene.

METHODS

A total of 100 milk samples, including 55 cows, 30 buffalos and 15 camels, were collected from different regions of north-western using direct milking and then transferred to the Food and Aquatic Health Laboratory under refrigerated conditions.

RESULTS

The results showed that out of 100 milk samples examined, 5 samples (5%) were contaminated, and T. gondii DNA was detected in the milk samples of 2 (3.63%) cows, 1 (3.33%) buffalos and 2 (13.33%) camels, respectively.

CONCLUSIONS

Our findings reveal that raw milk contaminated with T. gondii can be an important route of transmission of infection for human beings.

Seroprevalence of Toxoplasma gondii and Neospora caninum in camels recently imported to Egypt from Sudan and a global systematic review

INTRODUCTION

Toxoplasma gondii and Neospora caninum are closely related intracellular protozoan parasites of medical and veterinary concern by causing abortions and systemic illness. Limited or ambiguous data on the prevalence of T. gondii and N. caninum in camels triggered us to conduct this study.

METHODS

Camels (n = 460) recently imported from Sudan and destined mainly for human consumption, were tested for specific antibodies against these protozoans using commercially available ELISAs. From the two only quarantine stations for camels from Sudan, 368 camels were sampled between November 2015 and March 2016 in Shalateen, Red Sea governorate, and 92 samples were collected between September 2018 and March 2021 from Abu Simbel, Aswan governorate.

RESULTS & DISCUSSION

Overall, seropositive rates in camels were 25.7%, 3.9% and 0.8% for T. gondii, N. caninum and mixed infection, respectively. However, marked differences were found between the two study sites and/or the two sampling periods: For T. gondii, a higher rate of infection was recorded in the Red Sea samples (31.5%, 116/368; odds ratio 20.7, 5.0-85.6; P<0.0001) than in those collected in Aswan (2.2%, 2/92). The opposite was found for N. caninum with a lower rate of infection in the Red Sea samples (0.82%, 3/368; odds ratio 23.7, 6.7-83.9; P<0.0001) than in the samples from Aswan (16.3%, 15/92). Additionally, our systematic review revealed that the overall published seroprevalence of T. gondii and N. caninum was 28.6% and 14.3% in camels worldwide, respectively. To the best of our knowledge, this study provides the first record of seroprevalence of both T. gondii and N. caninum in recently imported camels kept under quarantine conditions before delivery to other Egyptian cities and regions. In addition, our review provides inclusive data on the prevalence of T. gondii and N. caninum in camel globally. This knowledge provides basic data for the implementation of strategies and control measures against neosporosis and toxoplasmosis.

Toxoplasma gondii in Foods: Prevalence, Control, and Safety

Toxoplasma gondii is an obligate intracellular parasite that causes toxoplasmosis, with approximately one third of the population around the world seropositive. The consumption of contaminated food is the main source of infection. These include meat products with T. gondii tissue cysts, and dairy products with tachyzoites. Recently, contamination has been detected in fresh products with oocysts and marine products. Despite the great health problems that are caused by T. gondii, currently there are no standardized methods for its detection in the food industry. In this review, we analyze the current detection methods, the prevalence of T. gondii in different food products, and the control measures. The main detection methods are bioassays, cell culture, molecular and microscopic techniques, and serological methods, but some of these do not have applicability in the food industry. As a result, emerging techniques are being developed that are aimed at the detection of multiple parasites simultaneously that would make their application more efficient in the industry. Since the prevalence of this parasite is high in many products (meat and milk, marine products, and vegetables), it is necessary to standardize detection methods, as well as implement control measures.

Toxoplasma gondii Infection and Threatened Abortion in Women from Northern Peru

Introduction

Toxoplasma gondii infection can cause important complications during pregnancy. Threatened abortion may be a late indicator for infection in settings with high prevalence of toxoplasmosis. We aimed to determine the association between T. gondii infection and threatened abortion in women from northern Peru.

Methods

We conducted a secondary analysis of a cross-sectional study in pregnant women from a hospital and a rural community in Lambayeque, Peru. Exposure variable was serological diagnosis of toxoplasmosis, defined as the demonstration of either IgM or IgG antibodies against T. gondii. Outcome variable was threatened abortion, defined as the diagnosis of bloody vaginal discharge or bleeding during the first half of pregnancy. Prevalence ratios were estimated in simple and multiple regression analyses.

Results

Of 218 pregnant women, 35.8% presented positive serology for T. gondii and 14.7% had threatened abortion in their current pregnancy. Pregnant women with positive T. gondii infection had 2.45-fold higher frequency of threatened abortion (PR: 2.45, 95% CI: 1.15-5.21). In addition, the frequency of threatened abortion decreased by 9% for each additional year of age (PR: 0.91, 95% CI: 0.86-0.97). A previous history of threatened abortion also showed a higher frequency of threatened abortion (PR: 5.22, 95% CI: 2.45-11.12).

Conclusions

T. gondii infection is associated with threatened abortion. An early age of pregnancy and a previous history of abortion are also associated with this condition.

A Meta-Analysis of the Prevalence of Toxoplasmosis in Livestock and Poultry Worldwide

Toxoplasma gondii causes toxoplasmosis with a global prevalence in the world. A large proportion of human illness is most frequently associated with consuming raw and undercooked meat or other animal products containing infective parasitic stages of T. gondii. This systematic review and meta-analysis study evaluated the prevalence of toxoplasmosis in cattle, sheep, camels, goats, and poultry worldwide. The search was performed in databases including PubMed, WoS, Scopus, Science Direct, Google Scholar, and ISC from 2000 to 2019 in Persian and English. The main inclusion criteria were the prevalence of toxoplasmosis among livestock and poultry and the prevalence indices by sample size. During these 20 years, the overall prevalence of toxoplasmosis in livestock and poultry was 28.3% (95% confidence interval (CI) 25-31.9%) using the random-effects meta-analysis model. The highest prevalence of T. gondii in livestock and poultry animals was found in Asia in 2014 with 89.8% (95% CI 78.5-95.5%). The lowest prevalence was found in Asia in 2013 with 1.26% (95% CI 0.4-3.8%). A quarter of livestock and poultry were infected with T. gondii. Since livestock products are globally important sources of people's diet, our findings are useful for policymakers to control T. gondii infection in livestock.

Hygiene measures as primary prevention of toxoplasmosis during pregnancy: A systematic review

Background Hygiene measures are recommended to prevent toxoplasmosis during pregnancy, although screening for seroconversion in pregnant women currently are debated and practices vary among countries. Objectives The purpose of this systematic literature review was to assess the effectiveness of hygiene measures during pregnancy to prevent toxoplasmosis infection. Search Strategy We followed the standard MOOSE and PRISMA criteria when conducting this systematic review and reporting the results. Selection criteria A systematic literature search was conducted for studies focused on congenital toxoplasmosis prevention, toxoplasmosis prevention during pregnancy, toxoplasmosis prevention and hygiene measures, which were published between 1970 and August 2020, using the databases of PubMed, Scope Med, EMBASE, and the Cochrane library. Data collection and analysis Our literature search identified 3964 articles, 3757 were excluded after review of title or abstract and 67 studies were considered relevant to the subject. We reviewed risk factors for toxoplasmosis infection during pregnancy and for congenital toxoplasmosis, preventive measures for toxoplasmosis during pregnancy, including: dietary recommendations, pet care measures, environmental measures, knowledge of risk factors and ways to control toxoplasmosis infection, knowledge of risk factors for infection by health professionals, knowledge of primary prevention measures by pregnant women. Conclusion: Hygiene measures are effective and applicable primary prevention to reduce toxoplasmosis and avoid congenital toxoplasmosis and its consequences. Funding No.

Detection of Specific IgG-Antibodies Against Toxoplasma gondii in the Serum and Milk of Domestic Donkeys During Lactation in China: A Potential Public Health Concern

Toxoplasma gondii is a worldwide zoonotic protozoan. Donkeys are often susceptible to many pathological agents, acting as carriers of pathogens for other animal species and humans. However, data on the prevalence of T. gondii in donkeys during lactation and on the status of antibodies against T. gondii in donkey milk are lacking. A cross-sectional study evaluated the variation of the anti-T. gondii antibodies in the blood and milk of domestic donkeys during lactation. A total of 418 domestic donkeys were randomly selected from the Shandong province, eastern China from January 2019 to March 2020. The anti-T. gondii antibodies were found in 11.72% (49/418) serum and 9.81% (41/418) milk samples using a commercial ELISA kit, respectively. There was a very high consistency between the serum and milk (Spearman’s coefficient = 0.858, p-value < 0.0001 and Kendall’s tau = 0.688, p-value < 0.0001), particularly at the 45th to 60th day of lactation. The present results of the statistical analysis showed that the history of abortion (p = 0.026; adjusted OR = 2.20; 95% CI: 1.15–4.20) and cat in the house (p = 0.008; adjusted OR = 2.36; 95% CI: 1.26–4.44) were significantly associated with T. gondii infection in the domestic donkeys. This is the first report to detect antibodies against T. gondii in donkey milk in China. These results indicate a potential risk of humans contracting the infection through the consumption of raw milk from the naturally infected donkeys.

First detection of anti-Toxoplasma gondii antibodies in domestic goat's serum and milk during lactation in China

Goat milk is considered as one of the most suitable substitute for human milk, especially for children, the aged and those with cow milk allergies. Consumption of raw or unpasteurized goat milk has been known to be a potential route of Toxoplasma gondii infection for human beings. However, no studies have been carried out to detect T. gondii in goat milk in China. Thus, this stuy was firstly carried out to detect T. gondii IgG antibody in domestic goat's serum and milk during lactation by a commercial validated ELISA kit in China. In total, 10.49% (66/629) serum samples and 9.70% (61/629) milk samples randomly collected from Shandong and Jilin provinces were seropositive for anti-T. gondii IgG, respectively. A high correlation of S/P% value was obtained between serum and milk samples (Spearman's coefficient = 0.891, p-value <0.001 and Kendall's tau = 0.724, p-value < 0.001). Statistical analysis showed that history of abortion, source of water and source of fodder were considered to be highly related to the T. gondii infection in the investigated domestic goats. The present results provide important information for the control and prevention of toxoplasmosis in goats and human beings in China.

Herd-level contamination of Neospora caninum, Toxoplasma gondii and Brucella in milk of Iranian dairy farms

The bulk milk examination is a reliable screening tool for monitoring the quality of milk in the farms. The infection to Neospora caninum, Toxoplasma gondii and Brucella sp. Was evaluated in bulk milk samples of dairy farms in Hamedan province, West part of Iran. All the dairy farms (n = 149) were examined for N. caninum, T. gondii and Brucella infections using milk ring test (MRT), microbiology, serology (Enzyme-linked Immunosorbent Assay), and molecular techniques. Based on molecular methods, Brucella-infection was negative in all farms; while, 55 %, 5.4 % and 2.7 % of samples were positive for N. caninum, T. gondii and mix infection, respectively. The highest Neospora-infection was detected in the farms with history of abortion in fall and winter. There was significant association between Neospora-infection and the presence of dogs and rodents in the farms, herd size, and age of the animals. Also, a significant association was seen between Toxoplasma-infection and the presence of cats and rodents in the farms, as well as age of the animals. Average total bacterial count (TBC) was calculated 1.14 × 10⁶±1.1 × 10⁶. The highest TBC was in the farms from Central locations of studied area (5.7 × 10⁶±2.24 × 10⁶), farms with more than 120 animals (7.9 × 10⁶±2.8 × 10⁶), and farms with ≥50-months age (1.74 × 10⁶±6.3 × 10⁵) in spring and summer (6.9 × 10⁶±3.7 × 10⁶). The number of somatic cells was estimated between 1 × 10⁴ and 2 × 10⁶ (Average = 4.2 × 10⁵±3.39 × 10⁵). The current study was a comprehensive evaluation of Neospora, Toxoplasma and Brucella infections in milk samples of Iranian dairy farms for the first time. Neospora-infection is responsible for economic losses in the region. Health education and milk pasteurization are so helpful for inhibiting the milk borne diseases. To reduce the risk factors, predict and design the appropriate schemes like redundant of heterogeneous animals are recommended.

Seroprevalence and associated risk factors of Toxoplasma gondii infection in yaks (Bos grunniens) on the Qinghai-Tibetan Plateau of China

Toxoplasma gondii is an intracellular parasite that is extensively prevalent globally. Studies have indicated the presence of T. gondii infection in animals in some provinces of China, but little is known about T. gondii infection in yaks (Bos grunniens) on the Qinghai-Tibetan Plateau. In the current study, to determine the seroprevalence and associated risk factors of T. gondii, a total of 2784 serum samples were collected from 18 different sampling sites in eight counties of the Qinghai and Tibet regions of China from 2018 to 2019. Serum antibodies against T. gondii were detected in 261 yaks (9.38%) via enzyme-linked immunosorbent assay (ELISA). We found that seroprevalence differed significantly among different counties (ranging from 5.41% in Gangcha to 19.79% in Datong), by year in the Tibet Autonomous Region (from 2.34% in 2018 to 13.24% in 2019), and by age (from 5.59% in 0 < year ≤ 1 to 11.76% in year > 7) (p < 0.05). Climate, geographical conditions, and age are the main factors influencing T. gondii infection in yaks in these regions. Therefore, our study provides a data reference for public health and prevention of yak toxoplasmosis.

Epidemiological Survey of Toxoplasma gondii and Associated Risk Factors in Ruminant Species of the Khyber Pakhtunkhwa Province of Pakistan

Toxoplasma infection is one of the most common human parasitic diseases. During 2018-2020, in the rural areas of three districts of Pakistan, we surveyed a total of 451 animals, belonging to different asymptomatic ruminant species, to determine the prevalence of Toxoplasma gondii antibodies. We used ELISA assay as well as recorded some associated risk factors contributing to its transmission. IgM antibodies were detected in 17% and IgG in 13.4% of ruminant samples with the highest percentage, 10% for IgM and 8.6% for IgG in sheep. A strong significant association was found between antibodies and different species (IgM, ${\chi }^2=29$ .280, $P=.000$ , and IgG, ${\chi }^2=22.580$ , $P=.000$ ), respectively. Infection with T. gondii seems mainly associated with different geographic features and the presence of cats in the environment, low hygiene water systems and livestock that are mostly dependent on outdoor drinking and grazing. There was no significant association between IgM and age grouping ( ${\chi }^2=6.660$ , $P=0.840$ nor for IgG ( ${\chi }^2=8.136$ , $P=0.43$ ). The results of this study may be considered the starting point to promote the awareness about parasitic infections in ruminants in Pakistan in order to prevent this infection from further spreading.

A review of microbes and chemical contaminants in dairy products in sub-Saharan Africa

Animal milk types in sub-Saharan Africa (SSA) are processed into varieties of products using different traditional methods and are widely consumed by households to support nutritional intake and diet. Dairy products contain several microorganisms, their metabolites, and other chemical compounds, some with health benefits and many others considered as potential health hazards. Consumption of contaminated milk products could have serious health implications for consumers. To access the safety of milk products across SSA, studies in the region investigating the occurrences of pathogens as well as chemical compounds such as heat stable toxins and veterinary drug residues in animal milk and its products were reviewed. This is done with a holistic view in light of the emerging exposome paradigm for improving food safety and consumer health in the region. Herein, we showed that several published studies in SSA applied conventional and/or less sensitive methods in detecting microbial species and chemical contaminants. This has serious implications in food safety because the correct identity of a microbial species and accurate screening for chemical contaminants is crucial for predicting the potential human health effects that undermine the benefits from consumption of these foods. Furthermore, we highlighted gaps in determining the extent of viral and parasitic contamination of milk products across SSA as well as investigating multiple classes of chemical contaminants. Consequently, robust studies should be conducted in this regard. Also, efforts such as development cooperation projects should be initiated by all stakeholders including scientists, regulatory agencies, and policy makers to improve the dairy product chain in SSA in view of safeguarding consumer health.

Apicomplexan Protozoa Responsible for Reproductive Disorders: Occurrence of DNA in Blood and Milk of Donkeys (Equus asinus) and Minireview of the Related Literature

Donkeys may be susceptible to many pathological agents and may act as carriers of pathogens for other animal species and humans. This study evaluated the occurrence of potentially abortifacient apicomplexan protozoa DNA in blood and milk samples collected at different time periods during lactation (1, 6, and 10 months) from 33 healthy dairy jennies. A total of 73 blood and 73 milk samples were used for DNA extraction and analysis. Blood specimens from 11/33 (33%) jennies scored positive for Theileria equi, while milk samples scored negative. Blood and milk of 3/33 jennies yielded DNA of Toxoplasma gondii at 6 months (n. 1) and 10 months (n. 2) after parturition. Neospora caninum DNA was found in four milk and in five blood samples only at one month after parturition. This study is the first report about the presence of N. caninum DNA in milk of naturally infected jennies. Moreover, the excretion of N. caninum DNA in some of these jennies at 30 days from the parturition may suggest a possible occurrence of an endogenous cycle, while the presence of T. gondii DNA in the milk collected at 6 and 10 months after parturition may be suggestive of a discontinuous excretion.

Public Health Significance of Toxoplasma gondii Infections in Cattle: 2009-2020

Toxoplasma gondii infections are common in humans and animals worldwide. The ingestion of food or water contaminated with oocysts excreted by infected cats or ingesting uncooked or undercooked meat containing tissue cysts of T. gondii are the 2 major modes of transmission of T. gondii. Viable T. gondii is more prevalent in pork and lamb than in beef. In the past decade, there have been many articles on the high seroprevalence in cattle, particularly from China. There is a report of an outbreak of acute toxoplasmosis in humans suspected to be linked to the ingestion of Artisan fresh cheese from cow's milk. There are conflicting reports concerning the rate of congenital transmission of T. gondii in cattle, especially from Brazil. In a report from Brazil, viable T. gondii was isolated from the blood of 1 of 60 pregnant cows slaughtered at an abattoir and from 1 fetus. The role of beef in the epidemiology of T. gondii infections is still not clear. Here, we review prevalence, persistence of infection, clinical disease, epidemiology, and public health risks of T. gondii infections in cattle from beef and cow's milk worldwide for the past decade.

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.

Foodborne transmission of Toxoplasma gondii infection in the last decade. An overview

Toxoplasmosis is a zoonotic disease of global distribution and importance. It is caused by the protozoan parasite Toxoplasma gondii, the only species in the Toxoplasma genus. This parasite can infect most warm-blooded animals, including humans and livestock. Main routes of transmission are by ingestion of tissue cysts in raw or undercooked meat of infected animals, ingestion of raw vegetables or water contaminated with T. gondii oocysts from cat feces, and transplacental. Around one-third of human beings are chronically infected with T. gondii. Most infections appear to be asymptomatic in immunocompetent persons, but toxoplasmosis can be fatal to the fetus and immunocompromised adults. Water and foodborne outbreaks have been caused by this parasite worldwide, but few are well documented. Importantly, T. gondii is a parasite of high importance in animal health, causing reproductive failure, particularly in small ruminants, and clinical toxoplasmosis in many species. This overview discusses the knowledge of T. gondii infections in the last decade focusing on the foodborne transmission of this parasite.

Zoonotic risks of pathogens from sheep and their milk borne transmission

Sheep were domesticated around 9000 BC in the Middle East, and since then milk from sheep gradually became very popular, not only for drinking but also for making cheeses and other dairy products. Nowadays, these dairy products are also important for people with an allergy to cow milk, and these products are an essential part of the local daily diet in regions of the world that are not suitable for cows and goats. Consumption of raw milk and raw milk products has a zoonotic risk, and with regard to sheep, the main pathogens associated with such dairy products are: Brucella melitensis, Campylobacter spp., Listeria spp., Salmonella spp., Shiga-toxin producing Escherichia coli, Staphylococcus aureus, tick borne encephalitis virus, and Toxoplasma gondii. Especially, young children, elderly people, pregnant women and immunocompromised (YOPI) persons, and those suffering from disease should be aware of the risk of consuming raw milk and raw milk products. This latter risk can be reduced by proper flock health management, prevention of contamination during milking, adequate milk processing, transport, and refrigerated storage. Only processes equaling pasteurization sufficiently reduce zoonotic risks from milk and milk products, but proper cooling is essential and recontamination must be prevented. Therefore, strict hygiene practices throughout the production process and supply chain especially for raw milk and raw dairy products, should be applied. Small scale production systems pose a greater risk compared to industrialized production systems because of a less protocolized and controlled production process. This manuscript describes zoonotic risks of pathogens from sheep and their milk borne transmission. Additionally, routes of contamination, possibilities for multiplication, and prevention measures thereof are described. We summarize some major human outbreaks caused by consumption of sheep milk and products made thereof, and finally discuss their implications.

Zoonotic parasites of dromedary camels: so important, so ignored

With a global population of about 35 million in 47 countries, dromedary camels play a crucial role in the economy of many marginal, desert areas of the world where they survive under harsh conditions. Nonetheless, there is scarce knowledge regarding camels' parasite fauna which can reduce their milk and meat productions. In addition, only scattered information is available about zoonotic parasites transmitted to humans via contamination (e.g. Cryptosporidium spp., Giardia duodenalis, Balantidium coli, Blastocystis spp. and Enterocytozoon bieneusi), as foodborne infections (e.g. Toxoplasma gondii, Trichinella spp. and Linguatula serrata) or by arthropod vectors (Trypanosoma spp.). Herein, we draw attention of the scientific community and health policy-making organizations to the role camels play in the epidemiology of parasitic zoonotic diseases also in the view of an increase in their farming in desert areas worldwide.

Meta-analysis of Toxoplasma gondii in pigs intended for human consumption in Mainland China

Toxoplasma gondii, is one of the most important foodborne zoonotic pathogens, which can infect virtually all warm-blooded animals, including pigs, and causes severe illness in congenitally infected infants and even death in patients with AIDS. Pigs (Sus scrofa) are one of the most important intermediate hosts of T. gondii, and human transmission occurs through consumption of raw or poorly cooked pork. In this systematic review and meta-analysis, we searched Chongqing VIP, Wanfang, Chinese Web of Knowledge, PubMed, and ScienceDirect databases for published papers regarding Toxoplasma infection in pigs in China, from inception to Oct 29, 2017. Search strings included whether they reported the samples of more than 30 pigs and provided information that allowed us to establish the prevalence of Toxoplasma infection. Moreover, we excluded repeated studies, reviews, other host studies, as well as studies with inconsistent data, incomplete information, those that only provided prevalence data, and those outside of Mainland China. We extracted the numbers of pigs with Toxoplasma infection from the obtained studies, and calculated the pooled prevalence of Toxoplasma infection in the pigs using a random-effects model. The data of 44 articles (including data on 46,723 pigs) were compliant with the standards. The pooled prevalence of T. gondii infection in pigs in China was 29% (95% CI 24-34), with 25% (95% CI 18-32) in pigs sampled before 2010 and 28% (95% CI 21-36) in pigs sampled in 2010 or later. The pooled prevalence of T. gondii in pigs from Northeast China (20%, 95% CI 14-26) was significantly lower than those from other regions (North China: 40%, 95% CI 32-47; Northwest China: 32%, 95% CI 13-51; East China: 30%, 95% CI 20-41; and South China: 35%, 95% CI 26-45; Central China: 23%, 95% CI 14-31; Southwest China: 33%, 95% CI 15-52). The estimated pooled prevalence of T. gondii infection was 36% (95% CI 25-47, 8,018/21,892) in pigs tested by ELISA, 24% (95% CI 19-28, 4,304/18,608) in pigs examined by IHA, and 19% (95% CI 8-31, 1,041/6,223) in pigs detected by other methods. Moreover, 1202 of 7470 piglets were detected as T. gondii-positive, and the prevalence (17%) was lower than that in fattening pigs (25%, OR = 1.28), sows (34%, OR = 2.13), and breeding boars (35%, OR = 2.46). Our findings suggested that toxoplasmosis is common in pigs in Mainland China. It is necessary to monitor the prevalence of T. gondii in pigs, and powerful and effective regulatory measures should be undertaken to reduce human exposure to T. gondii via the consumption of pork.

Toxoplasma gondii in naturally infected goats: Monitoring of specific IgG levels in serum and milk during lactation and parasitic DNA detection in milk

The zoonotic protozoa Toxoplasma gondii is one of the major abortive pathogens in small ruminants. Nevertheless, data on T. gondii infection in goats during lactation and on the presence of T. gondii in goat milk are lacking. A longitudinal study was planned in a T. gondii naturally infected dairy goat farm with the aim of (i) evaluating the variation of anti-T. gondii antibodies in blood and milk during the lactation; (ii) identifying the optimal phase during lactation for T. gondii monitoring; (iii) detecting the presence of T. gondii DNA in the milk. From March to July 2017, 30 goats in a farm were fortnightly visited seven times and sampled for blood and, when in lactation, for milk. Individual data regarding age, reproductive disorders, and the day of lactation were recorded. For the detection of anti-T. gondii antibodies in blood and milk a commercial ELISA kit was used. Milk samples (n = 63) of selected nine seropositive animals were also molecularly analysed to amplify a sequence within the ITS1 region of T. gondii. The seroprevalence of T. gondii infection was 63.3% (19/30); a high agreement was obtained between serum and milk results (Spearman's coefficient = 0.793 and Kendall's tau = 0.624), particularly between the 15^th and the 60^th day of lactation. In the statistical analysis, performed with generalized linear mixed models (GLMMs), the variable "phase of lactation" was strongly associated to ELISA values obtained in both serum and milk (p-value = 0.0001, F = 5.197, and p-value = 0.016, F = 2.755, respectively). Finally, molecular analyses revealed the presence of parasitic DNA in 20.6% (13/63) of milk samples, with a discontinuous parasite excretion; statistical analyses did not reveal any association among the parasite excretion and the considered variables. Milk could be considered as a valid alternative to blood for monitoring T. gondii infection in goat herds. Moreover, the detection of T. gondii DNA in milk enhanced the possibility for raw goat's milk consumption to be considered as a risk to public health.

Potential Hazards Associated with Raw Donkey Milk Consumption: A Review

Donkey milk can be used as a substitute for infants and children who suffer from cow milk proteins intolerance and multiple food hypersensitivity. Up to date, this is one of the main reasons why donkey milk has become a substantial area for reasearch, with an increase over the the last fifteen years. In donkey milk chain, risk analysis should be the object of particular attention because children are the main consumers of this food. In fact, this process is one of the main tool to achieve a high level of protection of human health and life; thus, the most important safety hazards should be monitored in order to attain this goal. This review focuses on the main hazards possibly present in raw donkey milk, including bacteria, fungal toxins, parasites, and chemical pollutants. Literature data have been considered, including some information that is not provided in the international literature. In the authors' opinion, the current scientific knowledge should be improved, with the aim of allowing a suitable risk assessment along the whole donkey milk chain. However, in the meantime, the competent authorithies must carry out more stringent official controls, with particular attention given to the level of primary production. The issue of a traceability system in donkey milk chain should be considered of paramount importance.

Detection and genotypic characterization of Toxoplasma gondii DNA within the milk of Mongolian livestock

Toxoplasma gondii is a global, zoonotic parasite capable of infecting any warm-blooded host. Toxoplasmosis can cause a variety of illnesses including abortions and congenital defects in humans, sheep, and goats. Congenital toxoplasmosis is considered to have the highest global disease burden of any foodborne illness in humans. This study examined the potential role of milk as a route of T. gondii transmission between livestock and humans within Mongolian herders, a little-studied population which relies heavily on animals. Milk of Mongolian sheep, goats and Bactrian camels was tested for the presence of T. gondii DNA, and a survey was conducted to ascertain what behavioral and environmental factors were present that might potentiate T. gondii infection within these Mongolian communities. T. gondii DNA was detected in samples from one sheep and five camels. Sequence analysis of DNA from camel milk revealed that two were from potentially virulent T. gondii genotypes. This has implications for public health in the region, as milk is an extremely important source of nutrition and our survey results imply that some people believe consumption of raw camel milk carries health benefits. This is the first report of T. gondii DNA in Bactrian camel milk as well as the first genotypic characterization of T. gondii within Mongolia.

Public health risks associated with food-borne parasites

Parasites are important food‐borne pathogens. Their complex lifecycles, varied transmission routes, and prolonged periods between infection and symptoms mean that the public health burden and relative importance of different transmission routes are often difficult to assess. Furthermore, there are challenges in detection and diagnostics, and variations in reporting. A Europe‐focused ranking exercise, using multicriteria decision analysis, identified potentially food‐borne parasites of importance, and that are currently not routinely controlled in food. These are Cryptosporidium spp., Toxoplasma gondii and Echinococcus spp. Infection with these parasites in humans and animals, or their occurrence in food, is not notifiable in all Member States. This Opinion reviews current methods for detection, identification and tracing of these parasites in relevant foods, reviews literature on food‐borne pathways, examines information on their occurrence and persistence in foods, and investigates possible control measures along the food chain. The differences between these three parasites are substantial, but for all there is a paucity of well‐established, standardised, validated methods that can be applied across the range of relevant foods. Furthermore, the prolonged period between infection and clinical symptoms (from several days for Cryptosporidium to years for Echinococcus spp.) means that source attribution studies are very difficult. Nevertheless, our knowledge of the domestic animal lifecycle (involving dogs and livestock) for Echinoccocus granulosus means that this parasite is controllable. For Echinococcus multilocularis, for which the lifecycle involves wildlife (foxes and rodents), control would be expensive and complicated, but could be achieved in targeted areas with sufficient commitment and resources. Quantitative risk assessments have been described for Toxoplasma in meat. However, for T. gondii and Cryptosporidium as faecal contaminants, development of validated detection methods, including survival/infectivity assays and consensus molecular typing protocols, are required for the development of quantitative risk assessments and efficient control measures.

Toxoplasma gondii infection and food consumption: A systematic review and meta-analysis of case-controlled studies

BACKGROUND

Toxoplasmosis is a zoonotic disease causing severe symptoms in pregnant women and immunocompromised individuals. On average, worldwide, around 30% of people are seropositive. The oral transmission route is of great significance and food, particularly meat, is an important transmission vehicle for T. gondii. However, the role of different food matrices is debated.

OBJECTIVES

The aim of this review was to assess the risk of humans developing acute T. gondii infection via the foodborne route.

STUDY ELIGIBILITY CRITERIA

Case-control studies including acute cases of T. gondii infection were included after literature searches, without time limits, in several databases. All studies estimating the risk of acquiring T. gondii infection after consumption of specific food categories were included.

RESULTS

Three risk factors proved to be significantly associated with acute T. gondii infection in humans: consumption of raw/undercooked meat, Odds Ratio (OR) 3.44 (1.29-9.16), consumption of raw/undercooked beef, OR 2.22 (1.57-3.12), and consumption of raw/undercooked sheep meat, OR 3.85 (1.85-8.00). Consumption of raw/undercooked pork, raw eggs, and unpasteurized milk proved to be non-significant risk factors.

LIMITATIONS

Limitations in the present review and meta-analysis are due to the low number of case-control studies available for analysis and the lack of a search strategy targeting gray literature.

CONCLUSION

Consumption of raw/undercooked beef and sheep meat are important risk factors for T. gondii infection. Their consumption should be avoided in order to prevent toxoplasmosis, particularly by those in at-risk categories, including pregnant women. The review protocol is registered in PROSPERO database (CRD42016043295).