Seroepidemiology of Toxoplasma gondii in domestic cattle, sheep, goats and pigs from São Tomé and Príncipe

Global prevalence and risk factors associated with Toxoplasma gondii infection in wild birds: A systematic review and meta-analysis

A systematic review and meta-analysis were performed to identify the global prevalence and factors associated with Toxoplasma gondii infection in wild birds. Six bibliographic databases (Chinese National Knowledge Infrastructure, VIP Chinese Journal Database, Wanfang Data, PubMed, Web of science and ScienceDirect) were searched from inception to February 2023. The search yielded 1220 records of which 659 articles underwent full-text evaluation, which identified 49 eligible articles and 16,030 wild bird samples that were included in the meta-analysis. The estimated pooled global prevalence of T. gondii infection in wild birds was 16.6%. Out of the variables tested, publication year after 2020 and climate type were significantly associated with T. gondii infection (P<0.01). Our data indicate that the prevalence of T. gondii in wild birds can be influenced by epidemiological variables. Further research is needed to identify the biological, environmental, anthropogenic, and geographical risk factors which impact the ecology and prevalence of T. gondii in wild birds.

Comparison of molecular techniques for the detection of Toxoplasma gondii in raw bovine milk from small rural properties in Brazil

This study aimed to research Toxoplasma gondii DNA in 102 samples of raw bovine milk from expansion tanks, in small properties located in different cities of the Midwest region of São Paulo, Brazil. For this, polymerase chain reaction (PCR) was performed with the primers TOX4/TOX5 for cPCR (conventional PCR), TgNP1/TgNP2 gene for nested PCR and the Tg18s58F/Tg18s348R for nested PCR. It was possible to detect T. gondii DNA in 18 (17.65 %) milk samples from the 102 tanks, corresponding to 4.90 % for TOX4/TOX5 primers, 12.74 % for TgNP1/TgNP2 gene and 0.98 % for Tg18s58F/Tg18s348R gene. The results showed that the TgNP1 and TgNP2 genes were more efficient to detect T. gondii DNA, and also indicated the importance of raw bovine milk as a source of human infections caused by this protozoan, being a public health problem. It is important to continue studies involving T. gondii from bovine milk considering the need for proper pasteurization, and for better comprehension regarding the epidemiology of this protozoan.

Seroprevalence of Toxoplasma gondii infection in sheep and cattle in Shanxi Province, North China

Toxoplasmosis is a worldwide zoonotic disease caused by infection with the intracellular protozoan parasite Toxoplasma gondii, posing significant economic losses to the livestock industry. As a major livestock province, little is known of the prevalence of T. gondii infection in sheep and cattle in Shanxi Province, North China. In this study, a total of 1962 blood samples from cattle (n = 978) and sheep (n = 984), collected from 11 administrative cities in Shanxi Province, were examined for antibodies against T. gondii by using the indirect enzyme linked immunosorbent assay (ELISA) kits commercially available. The results showed that antibodies to T. gondii were detected in 306 of the 978 cattle serum samples (31.29%, 95% CI 28.38-34.19), ranging from 12.64% to 60.00% among the different cities. The overall seroprevalence of T. gondii in sheep was 17.78% (175/984, 95% CI 15.40-20.17), ranging from 2.22% to 41.11% among the different administrative cities. The T. gondii seroprevalence was associated with the management mode and geographical location. This is the first report of T. gondii seroprevalence in cattle and sheep in Shanxi Province, North China, which provides baseline data to plan future control strategies for T. gondii infection in this province.

Seroprevalence and risk assessment of Toxoplasma gondii infection in sheep and goats in North and Beqaa governorates of Lebanon

Background and Aim:

Toxoplasmosis is a disease caused by the protozoan parasite Toxoplasma gondii that affects both humans and animals, leading to abortions and significant clinical manifestations in pregnant and immunocompromised hosts, in addition to massive economic losses in animal industries. Data from Lebanon are scarce regarding the seroprevalence of T. gondii infection in livestock. This study aimed to estimate the seroprevalence and assess the associated risk factors of T. gondii infection in sheep and goats in Lebanon.

Materials and Methods:

A cross-sectional study was carried out from May 2020 to April 2021. Blood samples from 150 sheep and 145 goats (total 295) destined for human consumption were obtained from 20 Lebanese farms located in the North and Beqaa governorates. The anti-T. gondii immunoglobulin G antibodies were assayed through means of a modified agglutination test with a cutoff titer of 20.

Results:

An overall seroprevalence of 48.5% (143/295) was reported: About 56.6% seroprevalence was found in sheep (85/150) and 40% (58/145) in goats. Adult age, female gender, and the wet season were significantly associated with an increased seropositivity rate of T. gondii infection (p < 0.001, p = 0.001, and p = 0.043, respectively).

Conclusion:

These results confirm the spread of T. gondii in sheep and goats destined for human consumption in various geographical regions in Lebanon. Therefore, continuous monitoring of T. gondii infection in livestock is warranted to control the spread of the infection and limit its potential transmission to humans through the consumption of raw or undercooked meat.

Geospatial epidemiology of Toxoplasma gondii infection in livestock, pets, and humans in China, 1984-2020

Undercooked or raw meat containing cyst-stage bradyzoites and oocyst-contaminated pets are presumed to constitute a major source of human toxoplasmosis. As the geospatial epidemiology of Toxoplasma gondii (T. gondii) infection in livestock, pets, and humans is rarely studied in China, we undertook a geospatial analysis using GIS visualization techniques. The present study retrieved information from the PubMed, China National Knowledge Infrastructure, and Baidu Scholar databases from 1984 up to 2020. All the data about the seroprevalence of T. gondii in livestock (sheep and goats, pigs, cattle and yaks), pets (cats, dogs), and humans in China were collected. Geospatial epidemiology of T. gondii infection in these hosts was performed using GIS. Results revealed that the estimated pooled seroprevalence of T. gondii was ranged from 3.98 to 43.02% in sheep and goats in China, 0.75 to 30.34% in cattle and yaks, 10.45 to 66.47% in pigs, 2.50 to 60.00% in cats, 0.56 to 27.65% in dogs, and 0.72 to 23.41% in humans. The higher seroprevalences of T. gondii were observed in sheep and goats in the districts of Chongqing, Zhejiang, and Beijing. The infection rates of T. gondii in cattle and yaks were higher in Guizhou, Zhejiang, and Chongqing. Also, the pigs from Chongqing and Guizhou were most severely infected with T. gondii. For cats, the districts of Shanxi, Hebei, and Yunnan had higher seroprevalences of T. gondii and, the infections among dogs were higher in Yunnan and Hebei as well. Furthermore, higher infection pressure of T. gondii exists in the districts of Taiwan and Tibet in humans. The geographical and spatial distribution of toxoplasmosis indicated that infection with T. gondii was widely spread in China, with a wide range of variations among the different hosts and regions in the country. Our results suggested that livestock and pets are not only a reservoir for the parasite but also a direct source of T. gondii infection for humans. It is important to control T. gondii infections in these animals that would reduce the risk of toxoplasmosis in humans.

Toxoplasma gondii Infection in Swine: Implications for Public Health

Toxoplasmosis, due to Toxoplasma gondii, is a parasitic disease with global importance. Among livestock, chronic T. gondii infection has been reported in higher rates in pigs and small ruminants, but with subclinical infections in case commonly encountered in pigs. Seroprevalence in the global pig population ranges according to the age or species of pigs, geographical distribution, production programs, and systems. Generally, T. gondii infections are noticed in low prevalence rates in conventional pig farms with high hygiene standards. In contrast, higher prevalence is common on free-ranging farms, outdoor or backyard small pig fams, as well as in farmed or hunted wild boars. The T. gondii average worldwide seroprevalence in pigs is reported to be 13% in Europe, 21% in Africa, 25% in North America, 21% in Asia, and 23% in South America. Human toxoplasmosis outbreaks have been correlated with the consumption of raw or undercooked meat, especially from infected pigs or wild boars, as well as of contaminated drinking water. The risk of infection in processed pork products is lower compared with fresh pork, as meat processing can reduce or inactivate T. gondii tissue cysts. Hence, the prevalence of T. gondii in the pig population may be a useful indicator of the risk of human toxoplasmosis associated with the consumption of pork products. The lack of obligatory screening methods at farm level for the detection of antibodies in farmed animals or the viable T. gondii in carcasses at slaughterhouse level increases the risk of contaminated pork or meat products. For this reason, the application of biosecurity and surveillance programs at farm level is very important to prevent a T. gondii infection.

The prevalence of Toxoplasma gondii in sheep in China: A systematic review and meta-analysis

Toxoplasmosis is a zoonotic disease caused by Toxoplasma gondii, which is widespread in warm-blooded animals and humans. Currently, many studies regarding T. gondii infection in sheep have been published worldwide. However, there is no meta-analysis of sheep infection in China. In this study, five databases were used to retrieve articles related to T. gondii in China. A total of 59 studies from 1987 to June 30, 2020, have been included. We estimated that the combined prevalence of T. gondii in the selected period was 8.5% (3197/28,099). In the analysis of publication year, the lowest positive rate after 2010 was 7.4% (1883/17,313). Geographically, the highest prevalence of T. gondii in sheep was recorded in Southwest China 19.2% (490/2080). Analysis according to age showed that the prevalence of infection in sheep older than 12 months was significantly (P < 0.05) higher than that in younger animals. The prevalence of T. gondii in sheep farmed by farmers was 7.2% (566/6336), which was higher than 5.3% (660/3121) of large-scale farming, suggesting a role for the feeding and husbandry. We also analyzed the impact of different geographic and climatic factors on the prevalence of T. gondii infection in sheep. The results showed that the prevalence was higher in low altitude, warm, humid, and high rainfall areas. We suggest that appropriate control programs should be formulated according to the differences in reproduction patterns and geographical conditions in different regions to reduce the prevalence of T. gondii among sheep in China.

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.

Prevalence of Toxoplasma gondii infection among animals in Algeria: A systematic review and meta-analysis

Toxoplasma gondii is a zoonotic parasite that can infect all warm-blooded animals. It is responsible for considerable economic losses in some regions and farming systems. This review aims to synthesize current findings on the prevalence and risk factors associated with T. gondii infection in animal species in Algeria. It was performed according to the recommendations of the PRISMA guideline. A total of 14 papers from 1955 to 2020 were eligible to be included in this systematic review and meta-analysis study including a number of 10,187 animals of which 2594 were positive cases (25.46 %) (24.62-26.31 %, 95 %CI). Prevalence of Toxoplasma-infection was 20.04 % in cattle, 22.57 % in sheep, 33.61 % in goats, 28.17 % in horses, 30 % in donkeys, 70.31 % in stray cats, 14.57 % in local rabbits, 30.47 % in dogs and 50.70 % in poultry farms. Adult animals and females were most infected. The highest prevalences were reported in stray cats and poultry. Rabbits were the least infected. This analysis showed a trend of increasing infection since 2015 (R² = 0.129, p > 0.05) which requires further studies to provide better prevention strategies.

Economic and public health importance of Toxoplasma gondii infections in sheep: 2009-2020

Toxoplasma gondii infections are common in humans and animals worldwide. The present review summarizes worldwide information on the prevalence of clinical and subclinical infections, epidemiology, diagnosis, control, and genetic diversity of T. gondii in sheep in the past decade. There is debate and uncertainty concerning repeat congenital infection as evidenced by finding T. gondii DNA in progeny of chronically infected sheep. However, there is no concrete evidence that T. gondii is the cause of repeated abortions in sheep. Recent data concerning pathogenesis of abortion in acutely infected sheep are reviewed. PCR-RFLP typing of T. gondii DNA derived from viable T. gondii isolates or tissues of infected sheep revealed low genetic diversity in sheep in Europe, Africa, Asia and North America but high diversity in South America. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.

All about Toxoplasma gondii infections in pigs: 2009-2020

Toxoplasma gondii infections are common in humans and animals worldwide. Toxoplasma gondii infection in pigs continues to be of public health concern. Pigs are important for the economy of many countries, particularly, USA, China, and European countries. Among the many food animals, pigs are considered the most important for T. gondii transmission in USA and China because viable parasites have rarely been isolated from beef or indoor raised chickens. Besides public health issues, T. gondii causes outbreaks of clinical toxoplasmosis in pigs in China, associated with a unique genotype of T. gondii (ToxoDB genotype #9 or Chinese 1), rarely found in other countries. The safety of ready to eat pork products with respect to T. gondii infection is a matter of recent debate. Here, we review in detail seroprevalence, prevalence of viable and nonviable T. gondii, epidemiology, risk assessment, diagnosis, and curing of pork products containing T. gondii for the past decade. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.