Antibodies to Toxoplasma gondii and Coxiella burneti among students and other personnel in veterinary colleges in California and Brazil

The global seroprevalence of Toxoplasma gondii infection in workers occupationally exposed to animals (1972-2023): a systematic review and meta-analysis

Toxoplasma gondii, a ubiquitous zoonotic parasite infecting warm-blooded animals, poses a significant health threat to workers with occupational animal exposure (WOEA) due to their frequent contact with potential reservoirs. Existing data on T. gondii seroprevalence in the WOEA exhibits substantial global variation. This systematic review and meta-analysis, adhering to PRISMA guidelines, aimed to quantify the global seroprevalence of T. gondii infection among WOEA over the past five decades (1972-2023). We identified 66 eligible studies through a comprehensive search strategy encompassing English publications, with a total sample size of 15,279. A random-effects model with the Freeman-Tukey transformation in STATA v16.0 accounted for the high heterogeneity observed. We estimated the pooled global seroprevalence of T. gondii infection in WOEA at 41% (95% CI: 36-47%). Subgroup analyses revealed significant variations by gender: males (63%) vs. females (37%) (p < 0.05), occupation: non-livestock workers (54%), livestock workers (47%), slaughterhouse workers (44%), and veterinary personnel (27%) (p < 0.05). Geographic trends showed the highest prevalence in Africa (51%), followed by South America (49%), Europe (47%), Australia (43%), Asia (36%), and North America (23%; p < 0.05). Lower prevalence was observed in high-income (39%) and upper-middle-income (38%) countries compared to lower-middle-income (44%) and low-income (48%) countries (p < 0.05). This analysis underscores the high global seroprevalence of T. gondii in the WOEA, highlighting the need for targeted interventions in this high-risk population.

First Insight into the Prevalence of Coxiella burnetii Infection among Veterinary Medicine Students in Bulgaria

The aim of this study was to assess the prevalence of Coxiella burnetii infection among veterinary medicine students from two Bulgarian Universities, located in Sofia and Stara Zagora. Blood samples were collected from a total of 185 veterinary students for the detection of C. burnetii phase II antibodies and presence of DNA using an enzyme-linked immunosorbent assay (ELISA) and end-point PCR test. Out of all samples, 29.7% were positive for at least one C. burnetii phase II antibody marker or by the result of the PCR test. Veterinary students from Stara Zagora showed a significantly high seropositivity for Q fever (33.6%), as compared to the students in Sofia (23%; p < 0.05). Evidence of recent exposure with detection of anti-C. burnetii phase II IgM (+) antibodies was observed in 14.6% of the students under study. Seroprevalence among students in Stara Zagora was higher (15.3%). Anti-C. burnetii phase II IgG antibodies were detected in 21.6% of examined samples. Our study revealed a higher seropositivity among the male students (32.8%) as compared to females (16.0%; p < 0.05). The end-point PCR assay detected 5.9% blood samples as positive. The relative risk (RR) of Q fever exposure for male students was 40.7%, whereas it was 24.6% in females (p < 0.05). The findings from this study indicate that the C. burnetii infection is widely distributed amongst veterinary students in Bulgaria. This study emphasizes the need for improved safety protocols and infection control measures in veterinary training programs.

Is there a higher risk of exposure to Coxiella burnetii for pre-clinical veterinary students?

Coxiella burnetii is globally distributed but evidence of zoonotic transmission in the Caribbean region is scarce. The bacterium presence is suspected on the Caribbean island of St. Kitts. The risk of exposure of veterinary students was reported in other regions of the world but is not documented in the Caribbean region. The present study aimed to evaluate the risk of exposure to C. burnetii for pre-clinical veterinary students (mostly coming from the U.S.) attending an island-based veterinary school. A cross-sectional study was conducted to compare incoming and outgoing veterinary students' seroprevalence. Serology was performed using indirect immunofluorescence assay to test Coxiella burnetii Phase I and Phase II immunoglobulins M and G. Background data were gathered using a standardized questionnaire. A parallel study enrolled veterinary school employees in the same university. Of the 98 participants (48 incoming and 50 outgoing students), 41 (41.8%, 95 %CI: 31.9-52.2) were seropositive to C. burnetii. There was no significant difference between the two groups (45.8% for incoming vs. 38.0% for outgoing students) (p = 0.4). No risk factors (demographic, animal handling practices or background) were significantly more reported in the seropositive group. In the employee study, the seroprevalence was high with 8/15 seropositives (53.3%, 95 %CI: 26.6-78.7). Pre-clinical veterinary students do not have a higher risk of exposure to C. burnetii by attending the veterinary school in St. Kitts, but they are highly exposed before arrival on the island (seroprevalence of 45.8%). Most of these participants had experience with animals either through farming or previous veterinary technician employment. This indicates a high exposure in the U.S. young population aiming to become veterinarians. There is an urgent need to increase C. burnetii surveillance in animals and humans to apply relevant prevention and control measures, including recommendations for vaccination of students and professionals at risk.

Q fever and coxiellosis in Brazil: an underestimated disease? A brief review

Q fever, caused by the γ-proteobacterium Coxiella burnetii, is a zoonosis of great importance and global impact. This agent has high transmissibility and can spread over long distances via wind, in which a small number of aerosolized particles are needed to infect susceptible hosts. The clinical diagnosis of Q fever is difficult owing to the variety of clinical signs shared with other diseases. In Brazil, studies related to C. burnetii are constantly being conducted, and this review aims to increase the number of approaches already studied, leading to the following question: is Q fever an unknown, neglected disease, or does it have a focal occurrence in certain areas (exotic/rare) in the country?

Molecular Detection of Coxiella burnetii in Unstandardized Minas Artisanal Cheese Marketed in Southeastern Brazil

Q fever is a zoonotic disease caused by Coxiella burnetii. The causative pathogen has been detected in dairy products, which raises the possibility of consumption of dairy products as a possible route of transmission; however, this has not been adequately described. Therefore, the aim of the present study was to investigate the presence of C. burnetii in 87 samples of artisanal cheeses made from unpasteurized raw milk sold in Minas Gerais, southeastern Brazil. The cheese samples were analyzed using quantitative real-time PCR (qPCR), and the products from positive samples were sequenced. In addition, 150 people were interviewed to outline the profile of consumers and the consumption of non-inspected dairy products. The results showed that 4.6% (4/87) of the samples were positive for C. burnetii, with 99.84% identity with the reference 16S gene. Responses from consumer interviews indicate that 95.3% (143/150) of respondents consume milk and dairy products; 50% (75/150) consume fresh Minas artisanal cheese and milk at least once a day; 64.58% (93/144) do not check the inspection stamps on the packaging at the time of purchase; and 81.56% (122/146) do not know the meaning of these stamps. Thus, the presence of C. burnetii DNA in the analyzed cheeses and the consumption of unstandardized dairy products raise an alert for the risk of transmission of Q fever in the population that consumes them.

Coxiella burnetii associated with BVDV (Bovine Viral Diarrhea Virus), BoHV (Bovine Herpesvirus), Leptospira spp., Neospora caninum, Toxoplasma gondii and Trypanosoma vivax in reproductive disorders in cattle

This is a cross-sectional study to assess the presence of antibodies in ruminants against selected pathogens associated with reproductive disorders in cattle in four Brazilian states, including the zoonotic agent Coxiella burnetii. The used tests were Virus Neutralization Assay for IBR and BVD, Microscopic Agglutination Test for Leptospira spp., Indirect Fluorescent Antibody Test (IFAT) for C. burnetii and Toxoplasma gondii, and Enzyme-Linked Immunosorbent Assay for Neospora caninum and Trypanosoma vivax. Seropositivity for C. burnetii was 13.7% with titers from 128 to 131,072; 57.8% for BoHV-1, with titers between 2 and 1,024; 47.1% for BVDV-1a, with titers from 10 to 5,120; 89.2% for N. caninum; 50% for T. vivax; and 52.0% for Leptospira spp., with titers between 100 to 800 (the following serovars were found: Tarassovi, Grippotyphosa, Canicola, Copenhageni, Wolffi, Hardjo, Pomona and Icterohaemorrhagiae); 19.6% for T. gondii with titer of 40. This is the first study that has identified C. burnetii in cattle associated with BoHV and BVDV, N. caninum, Leptospira spp., T. gondii and T. vivax. Thus, future studies should be conducted to investigate how widespread this pathogen is in Brazilian cattle herds.

[Coxiella burnetii and Q fever in Brazil: a public health issue]

Q fever is a zoonosis that is broadly distributed worldwide, despite few reports associated with its occurrence in Brazil. Coxiella burnetii, namely the causative agent of Q fever is a gram-negative coccobacillus and an obligate intracellular bacterial parasite of the order of Legionellales. The microorganism is generally present in the urine and feces of infected animals and can be found in large quantities in placental membranes of at-term or aborted animals. The inhalation of particles suspended in the air or contaminated aerosols is the most common form of bacterial contact. Q Fever is a self-limited disease, and often progresses in a benign way. In cases where the disease progresses to the chronic form, endocarditis is the most prevalent manifestation. Clinical diagnosis is difficult since the symptoms are similar to many other diseases. In confirmed cases, antibiotic therapy is the treatment indicated. Given the lack of knowledge about the disease and the difficulty of diagnosis, it is believed that Q fever is more common than generally believed in Brazil.

Seroprevalence of Toxoplasma gondii infection in cancer patients: A systematic review and meta-analysis

Toxoplasmosis, caused by Toxoplasma gondii, is a great public health concern in cancer patients, which can induce serious pathological effects. This systematic review and meta-analysis was performed to evaluate the worldwide seroprevalence rate of T. gondii infection among cancer patients. A search was conducted on five electronic databases that reported data on T. gondii seroprevalence in cancer patients. The searching process resulted in the inclusion of 57 studies. The results showed that T. gondii had the pooled prevalence of 30.8% in cancer patients using a random-effect model (95% CI: 26.3-35.6). Cancer patients had a higher overall prevalence of T. gondii infection, compared to those without cancer. Furthermore, the odds ratio of toxoplasmosis in cancer patients was 3.1 times, compared to that of controls (95% CI: 2.5-3.8, P < 0.0001). Toxoplasmosis had a higher prevalence in females (40%) than in males (33%). Furthermore, the age group of upper 40 years had the highest prevalence infection rate (30%). In addition, a significant association was also observed between toxoplasmosis infection and year (P < 0.001), type of cancer (P < 0.001), country (P < 0.001), gender (P < 0.001), age (P = 0.006) and diagnostic method (P < 0.001) in cancer patients. Considering the high prevalence of T. gondii infection in cancer patients and its serious outcomes, the researchers are suggested to carry out further studies to prevent and control toxoplasmosis among this population.

Serological diagnosis and risk factors for Coxiella burnetii in goats and sheep in a semi-arid region of Northeastern Brazil

Abstract Coxiella burnetii is a zoonotic agent transmitted mainly by small ruminants. In Brazil the disease has been classified as a notifiable disease since 2013, when human cases were reported. This study aimed to identify risk factors associated with the presence of anti- Coxiella burnetii antibodies in goats and sheep in a semiarid region of Northeastern Brazil. Sera of 412 goats and 403 sheep from municipality of Petrolina, Pernambuco, were examined by the Indirect Fluorescent Antibody Test (IFAT) against antigens of C. burnetii. Information about management variables (independent variables) that could be associated with the presence of the microorganism (dependent variables) were obtained from the supervisor of each farm. It was determined that 2.2% (9/412) of the goats and 2.1% (9/403) of the sheep had antibodies reactive to C. burnetii. The presence of anti-C. burnetii antibodies was associated with the dry area of the Sequeiro (a region in the northern part of the municipality of Petrolina) (P = 0.025), male sheep (P = 0.020), and intensive goat breeding (P = 0.005). This study therefore showed the presence of anti-C. burnetii antibodies in goat and sheep, confirming for the first time that this agent is likely circulating among goat herds in the Caatinga Biome, semi-arid of Brazil.

Seroprevalence of Toxoplasma gondii in the Iranian general population: a systematic review and meta-analysis

Toxoplasma gondii is one of the most common protozoan parasites with widespread distribution globally. It is the causative agent of Toxoplasma infection, which is prevalent in human and other warm-blooded vertebrates. While T. gondii infection in healthy people is usually asymptomatic, it can lead to serious pathological effects in congenital cases and immunodeficient patients. We sought to identify the seroprevalence rate of Toxoplasma infection in the Iranian general population to develop a comprehensive description of the disease condition in Iran for future use. Electronic databases (PubMed, Google Scholar, Science Direct, and Scopus) and Persian language databases (Magiran, Scientific Information Database [SID], Iran Medex, and Iran Doc) were searched. Furthermore, graduate student dissertations and proceedings of national parasitology congresses were searched manually. Our search resulted in a total of 35 reports published from 1978 to 2012.These include 22 published articles, 1 unpublished study, 8 proceedings from the Iranian conference of parasitology, and 4 graduate student dissertations, resulting in 52,294 individuals and 23,385 IgG seropositive cases. The random errors method was used for this meta-analysis. The result shows that the overall seroprevalence rate of toxoplasmos is among the general population in Iran was 39.3% (95% CI=33.0%-45.7%). There was no significant difference in the seroprevalence rate between male and female patients. A significant linear trend of increasing overall prevalence by age was noted (P<0.0001). In addition, the data indicates that there are high seroprevalence in groups who have direct contact with cats, consume uncooked meat and raw fruits or vegetables, in farmers and Housewife, individuals who have a low level of education, and live in rural areas. To the best of our knowledge, this is the first systematic review of T. gondii infection seroprevalence in Iran, which shows a high prevalence of Toxoplasma infection (more than one third). We highly recommend further study for the purposes of aiding patient management and developing more efficient diagnostic tests and effective prevention approaches.

Q fever in French Guiana

Coxiella burnetii, the causative agent of Q fever, is present worldwide. Recent studies have shown that this bacterium is an emerging pathogen in French Guiana and has a high prevalence (24% of community-acquired pneumonia). In this review, we focus on the peculiar epidemiology of Q fever in French Guiana. We place it in the context of the epidemiology of the disease in the surrounding countries of South America. We also review the clinical features of Q fever in this region, which has severe initial presentation but low mortality rates. These characteristics seem to be linked to a unique genotype (genotype 17). Finally, we discuss the issue of the animal reservoir of C. burnetii in French Guiana, which is still unknown. Further studies are necessary to identify this reservoir. Identification of this reservoir will improve the understanding of the Q fever epidemic in French Guiana and will provide new tools to control this public health problem.

Risk factors of Coxiella burnetii (Q fever) seropositivity in veterinary medicine students

Background

Q fever is an occupational risk for veterinarians, however little is known about the risk for veterinary medicine students. This study aimed to assess the seroprevalence of Coxiella burnetii among veterinary medicine students and to identify associated risk factors.

Methods

A cross-sectional study with questionnaire and blood sample collection was performed among all veterinary medicine students studying in the Netherlands in 2006. Serum samples (n = 674), representative of all study years and study directions, were analyzed for C. burnetii IgG and IgM phase I and II antibodies with an immunofluorescence assay (IFA). Seropositivity was defined as IgG phase I and/or II titer of 1∶32 and above.

Results

Of the veterinary medicine students 126 (18.7%) had IgG antibodies against C. burnetii. Seropositivity associated risk factors identified were the study direction ‘farm animals’ (Odds Ratio (OR) 3.27 [95% CI 2.14–5.02]), advanced year of study (OR year 6: 2.31 [1.22–4.39] OR year 3–5 1.83 [1.07–3.10]) having had a zoonosis during the study (OR 1.74 [1.07–2.82]) and ever lived on a ruminant farm (OR 2.73 [1.59–4.67]). Stratified analysis revealed study direction ‘farm animals’ to be a study-related risk factor apart from ever living on a farm. In addition we identified a clear dose-response relation for the number of years lived on a farm with C. burnetii seropositivity.

Conclusions

C. burnetii seroprevalence is considerable among veterinary medicine students and study related risk factors were identified. This indicates Q fever as an occupational risk for veterinary medicine students.

[Endocarditis due to Coxiella burnetii (Q fever): a rare or underdiagnosed disease? Case report]

Q fever is a zoonosis of worldwide distribution that is caused by Coxiella burnetii. However, reports of this disease in Brazil are rare. Seroepidemiological studies have shown relatively high frequencies of antibodies against Coxiella burnetii in populations with occupational exposure. In humans, it can be manifested clinically as acute or chronic disease. Endocarditis is the most frequent chronic form of Q fever and the form with the greatest morbidity and mortality. We report a severe case of endocarditis due to Coxiella burnetii acquired in Brazil that had a fatal outcome, despite specific antibiotic therapy and valve surgery treatment.

Questing one Brazilian query: reporting 16 cases of Q fever from Minas Gerais, Brazil

Q fever has been considered non-existing in Brazil where reports of clinical cases still cannot be found. This case-series of 16 patients is a result of a systematic search for such illness by means of clinical and serologic criteria. Serologic testing was performed by the indirect microimmunofluorescence technique using phase I/II C. burnetii antigens. Influenza-like syndrome was the most frequent clinical form (eight cases - 50%), followed by pneumonia, FUO (fever of unknown origin), mono-like syndrome (two cases - 12.5% each), lymphadenitis (one case - 6.3%) and spondylodiscitis associated with osteomyelitis (one case - 6.3%). The ages varied from four to 67 years old with a median of 43.5. All but one patient had positive serologic tests for phase II IgG whether or not associated with IgM positivity compatible with acute infection. One patient had both phase I and phase II IgG antibodies compatible with chronic Q fever. Seroconvertion was detected in 10 patients. Despite the known limitations of serologic diagnosis, the cases here reported should encourage Brazilian doctors to include Q fever as an indigenous cause of febrile illness.

Antibodies to Rickettsia rickettsii, Rickettsia typhi, Coxiella burnetii, Bartonella henselae, Bartonella quintana, and Ehrlichia chaffeensis among healthy population in Minas Gerais, Brazil

Rickettsial diseases except those belonging to spotted fever group rickettsioses are poorly studied in South America particularly in Brazil where few epidemiological reports have been published. We describe a serosurvey for Rickettsia rickettsii, R. typhi, Coxiella burnetii, Bartonella henselae, B. quintana, and Ehrlichia chaffeensis in 437 healthy people from a Brazilian rural community. The serum samples were tested by indirected micro-immunoflourescence technique and a cutoff titer of 1:64 was used. The seroprevalence rates for R. rickettsii, R. typhi, C. burnetii, B. henselae, B. quintana, and E. chaffeensis were respectively 1.6% (7 samples); 1.1% (5 samples); 3.9% (17 samples); 13.7% (60 samples); 12.8% (56 samples), and 10.5% (46 samples). Frequent multiple/cross-reactivity was observed in this study. Age over 40 years old, urban profession, and rural residence were significantly associated with some but not all infections rate. Low seropositivity rates for R. rickettsii, R. typhi, and C. burnetii contrasted with higher rates of seropositivity for B. quintana, B. henselae, and E. chaffeensis. These results show that all tested rickettsial species or antigenically closely related possible exist in this particular region.

Q fever in humans and animals in the United States

Coxiella burnetii, the etiologic agent of Q fever, is a worldwide zoonotic pathogen. Although Q fever is present in the United States, little is known about its current incidence or geographic distribution in either humans or animals. Published reports of national disease surveillance, individual cases, outbreak investigations, and serologic surveys were reviewed to better characterize Q fever epidemiology in the United States. In national disease surveillance reports for 1948-1986, 1,396 human cases were reported from almost every state. Among published individual case reports and outbreak investigations, occupational exposures (research facilities, farm environments, slaughterhouses) were commonly reported, and sheep were most frequently implicated as a possible source of infection. In studies conducted on specific groups, livestock handlers had a significantly higher prevalence of antibodies to C. burnetii than did persons with no known risk. Animal studies showed wide variation in seroprevalence, with goats having a significantly higher average seroprevalence (41.6%) than sheep (16.5%) or cattle (3.4%). Evidence of antibody to C. burnetii was reported among various wild-animal species, including coyotes, foxes, rodents, skunks, raccoons, rabbits, deer, and birds. This literature review suggests that C. burnetii is enzootic among ruminants and wild animals throughout much of the United States and that there is widespread human exposure to this pathogen. Sheep and goats appear to be a more important risk for human infection in the United States than cattle or wild animals, and research studies examining the natural history and transmission risk of Q fever in sheep and goats in this country should be encouraged.

[Prevalence of sheep toxoplasmosis determined by the Sabin-Feldman reaction in animals from Uruguaiana, RS, Brazil]

Determinou-se a prevalência de toxoplasmose ovina em soros de 100 animais, provenientes de Uruguaiana, RS e abatidos em Bragança Paulista, SP, Brasil, através de reação de Sabin-Feldman (RSF). Considerando-se animais positivos aqueles com títulos > ou = 16, obtiveram-se 39% de soro-reagentes, com títulos e percentuais de soropositividade correspondentes a: 16 (66,7%), 64 (23%), 256 (2,6%), 1024 (5,1) e 4000 (2,6%).

The importance of trophozoites in transmission of toxoplasmosis: survival and pathogenity of Toxoplasma gondii trophozoites in liquid media

It has been generally assumed that Toxoplasma gondii trophozoites cannot survive long outside the body, and that toxoplasmosis is transmitted by transplacental infection, cysts and oocysts. We tested the survival and pathogenicity of separated Toxoplasma trophozoites in saline, colostrum, and solutions of albumen and serum, and the penetration of Toxoplasma trophozoites from infected secretions through mucous membranes of nose, conjunctiva, and mouth. The trophozoites survived 24 h in saline, 3 days in 3.5% serum albumen, 3 days in colostrum, and 17-43 days in serum solutions. The infectivity of the trophozoites was highest after nasal instillation, second highest after instillation into conjunctiva, and lowest after instillation into the mouth. The infective dose was calculated. The results show that Toxoplasma trophozoites survive and remain infectious for a relatively long time in biological liquid media and can easily penetrate mucous membranes, and suggest a revised hypothesis for the transmission of Toxoplasmosis with the trophozoites as one important source of infection.