Artisan fresh cheese from raw cow's milk as a possible route of transmission in a toxoplasmosis outbreak, in Brazil

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.

Increased frequency of detection of anti-Toxoplasma gondii antibodies in domestic cats after outbreak of human toxoplasmosis

Toxoplasmosis affects various organisms, including humans. In 2018, the largest outbreak of human toxoplasmosis described so far was reported in southern Brazil, with 809 human cases reported, and water as the potentially primary source of infection. Therefore, in this study, we aimed to evaluate the seroprevalence of Toxoplasma gondii in naturally infected domestic cats before and after the human toxoplasmosis outbreak, as well as the potential for environmental contamination by the number of cats infected after the outbreak. We evaluated 381 serum samples from domestic cats in southern Brazil, using an indirect immunofluorescence assay, with samples considered positive at a titer of 1:20. We found that 73% (204/279) and 27% (75/279) of the samples analyzed before the outbreak were negative and positive, respectively. After the outbreak, 62% (69/112) were negative of the samples were and 38% (43/112) were positive. Notably, the proportion of positive samples before the outbreak before (27%) was significantly lower than that after the outbreak (38%; P = 0.020). Therefore, the increased seroprevalence of T. gondii in cats was probably correlated with the ingestion of contaminated water. Therefore, it is important to monitor animals, mainly definitive hosts, after toxoplasmosis outbreaks, considering that these animals can contaminate the environment and, consequently, humans.

Waterborne transmission of protozoan parasites: a review of worldwide outbreaks - an update 2017-2022

The current study presents a comprehensive review of worldwide waterborne parasitic protozoan outbreaks reported between 2017 and 2022. In total, 416 outbreaks were attributed to the waterborne transmission of parasitic protozoa. Cryptosporidium accounted for 77.4% (322) of outbreaks, while Giardia was identified as the etiological agent in 17.1% (71). Toxoplasma gondii and Naegleria fowleri were the primary causes in 1.4% (6) and 1% (4) of outbreaks, respectively. Blastocystis hominis, Cyclospora cayetanensis, and Dientamoeba fragilis were independently identified in 0.72% (3) of outbreaks. Moreover, Acanthamoeba spp., Entamoeba histolytica, Vittaforma corneae, and Enterocytozoon bieneusi were independently the causal agents in 0.24% (1) of the total outbreaks. The majority of the outbreaks (195, 47%) were reported in North America. The suspected sources for 313 (75.2%) waterborne parasitic outbreaks were recreational water and/or swimming pools, accounting for 92% of the total Cryptosporidium outbreaks. Furthermore, 25.3% of the outbreaks caused by Giardia were associated with recreational water and/or swimming pools. Developing countries are most likely to be impacted by such outbreaks due to the lack of reliable monitoring strategies and water treatment processes. There is still a need for international surveillance and reporting systems concerning both waterborne diseases and water contamination with parasitic protozoa.

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.

Present and pioneer methods of early detection of food borne pathogens

Food-borne pathogens are a severe threat to human illness and death world-wide. Researchers have reported more than 250 food-borne diseases. Most of these are infections caused by a wide variety of bacteria, viruses, and parasites. It has a significant economic impact also. Detection of pathogenic microbes is thus essential for food safety. Such identification techniques could meet the following parameters viz., the accuracy of detection techniques that are quick, efficient, economical, highly sensitive, specific, and non-labor intensive. The various available methods for detecting food pathogens are classified into different groups, each having its advantages and disadvantages. The conventional methods are usually the first choice of detection even though they are laborious. Modern techniques such as biosensors, immunological assays, and macromolecule-based (nucleic acid) methods are being developed and refined to overcome traditional methods' limitations. Early detection of pathogens and secure food safety at each stage of food processing to storage, utilizing improved methodologies are mandatory. This review summarizes the deadly food pathogens leading to significant outbreaks and discusses the importance of early detection methods and advanced detection methods in comparison.

Contamination of Soil, Water, Fresh Produce, and Bivalve Mollusks with Toxoplasma gondii Oocysts: A Systematic Review

Toxoplasma gondii is a major foodborne pathogen capable of infecting all warm-blooded animals, including humans. Although oocyst-associated toxoplasmosis outbreaks have been documented, the relevance of the environmental transmission route remains poorly investigated. Thus, we carried out an extensive systematic review on T. gondii oocyst contamination of soil, water, fresh produce, and mollusk bivalves, following the PRISMA guidelines. Studies published up to the end of 2020 were searched for in public databases and screened. The reference sections of the selected articles were examined to identify additional studies. A total of 102 out of 3201 articles were selected: 34 articles focused on soil, 40 focused on water, 23 focused on fresh produce (vegetables/fruits), and 21 focused on bivalve mollusks. Toxoplasma gondii oocysts were found in all matrices worldwide, with detection rates ranging from 0.09% (1/1109) to 100% (8/8) using bioassay or PCR-based detection methods. There was a high heterogeneity (I2 = 98.9%), which was influenced by both the sampling strategy (e.g., sampling site and sample type, sample composition, sample origin, season, number of samples, cat presence) and methodology (recovery and detection methods). Harmonized approaches are needed for the detection of T. gondii in different environmental matrices in order to obtain robust and comparable results.

Epidemiological study of toxoplasmosis outbreaks in Brazil

In Brazil, notification of toxoplasmosis outbreaks and epidemiological investigation is a mandatory activity of health surveillance. We investigated the risk factors for toxoplasmosis during outbreaks, notifications of outbreaks by the health secretary and reports in the literature. Other factors related to the municipalities were determined through the Institute of Geography and Statistics portal. We found that fruits and vegetables were the most described transmission routes in outbreaks, and oocysts were the most common parasitic form; in recent years; there has been an increase in outbreak notifications. We also found that municipalities with high municipal human development index have a higher number of toxoplasmosis infections during outbreaks. There is a need to raise awareness among the population and producers regarding good water management and quality practices and to facilitate the acquisition of complex data to improve preventive strategies.

Outbreaks of clinical toxoplasmosis in humans: five decades of personal experience, perspectives and lessons learned

Background

The protozoan parasite Toxoplasma gondii has a worldwide distribution and a very wide host range, infecting most warm-blooded hosts. Approximately 30% of humanity is infected with T. gondii, but clinical toxoplasmosis is relatively infrequent. Toxoplasmosis has a wide range of clinical symptoms involving almost all organ systems. In most persons that acquire infection postnatally, symptoms (when present) are mild and mimic other diseases such as flu, Lyme disease, Q fever, hematological alterations, or mumps. It is likely that clinical disease is more common than reported. The ingestion of infected meat or food and water contaminated with oocysts are the two main modes of postnatal transmission of Toxoplasma gondii. The infective dose and the incubation period of T. gondii infection are unknown because there are no human volunteer experiments.

Methods

Here, I have critically reviewed outbreaks of clinical toxoplasmosis in humans for the past 55 years, 1966–2020. Information from oocyst-acquired versus meat-acquired infections was assessed separately.

Results

Most outbreaks were from Brazil. There were no apparent differences in types or severity of symptoms in meat- versus oocyst-acquired infections. Fever, cervical lymphadenopathy, myalgia, and fatigue were the most important symptoms, and these symptoms were not age-dependent. The incubation period was 7–30 days. A genetic predisposition to cause eye disease is suspected in the parasites responsible for three outbreaks (in Brazil, Canada, and India). Only a few T. gondii tissue cysts might suffice to cause infection, as indicated by outbreaks affecting some (but not all) individuals sharing a meal of infected meat.

Conclusions

Whether the high frequency of outbreaks of toxoplasmosis in humans in Brazil is related to environmental contamination, poor hygiene, socioeconomic conditions, or to genotypes of T. gondii needs investigation.

Graphic Abstract

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.

Epidemiology of a toxoplasmosis outbreak in a research institution in northern Paraná, Brazil

Toxoplasmosis is a reportable disease in Brazil. The objective of this study was to investigate a toxoplasmosis outbreak at a research institution in Londrina-PR, Brazil. The outbreak was reported in October 2015; however, the first cases occurred in August 2015. Blood samples were collected from 674 persons at the institution. Samples were collected from soil, water (water tank) and food (vegetables) served in the restaurant. Each participant responded to an epidemiological questionnaire. For the blood samples, a chemiluminescent microparticle immunoassay was performed to detect IgM, IgG and specific IgG avidity antibodies; 10.8% (73/674) had evidence of acute toxoplasmosis. Statistical analysis showed a significant association (p < .001) between acute infection and eating lunch in the restaurant of the institution. Regarding the types of food offered in the restaurant during the period, there was a significant association between consuming raw salad (p < .001) and becoming ill. We conclude that the vegetables or raw vegetables served in the restaurant were probably the source of infection; however, the long period between exposure and case reporting made it difficult to identify the source of transmission.