Toxoplasma Seroprevalence Research Articles

Immunity Status of Blood Donors Regarding Toxoplasma gondii Infection in a Low-Income District of Abidjan, Côte d'Ivoire, West Africa.

Background. Toxoplasmosis is a widespread cosmopolitan anthropozoonosis, which affects more than a third of the world population. Except the modes of transmission well known, Toxoplasma gondii can be transmitted during transplantation or blood transfusion. The aim of this study is to determine the prevalence of IgG and IgM Toxoplasma gondii and to estimate the potential risk by blood products. Methods. This is a cross-sectional study on the research for Toxoplasma gondii antibodies (IgG and IgM) blood donors performed by ELISA. Results. An overall seroprevalence of Toxoplasma gondii among blood donors recruited was 67.92% (n = 72). Among these, 68 have Toxoplasma gondii IgG (64.15%), 12 Toxoplasma gondii IgM (11.32%), and 4 (3.77%) both. The risk varies between 8 for 100000 and 172 for 100000 donations. Conclusion. The need to strengthen security measures for people multitransfused, immunocompromised, and pregnant women to reduce the transmission of toxoplasmosis is important.

Seroprevalence of Rubella, CMV and Toxoplasma in women of reproductive age in a city in Turkey

Seroprevalence of Rubella, CMV and Toxoplasma in women of reproductive age in a city in Turkey

Toxoplasma gondiicoinfection with diseases and parasites in wild rabbits in Scotland

In wild rabbits (Oryctolagus cuniculus) on an estate in Perthshire, central Scotland, the seroprevalence of Toxoplasma gondii was 18/548 (3·3%). The wild rabbit could be a T. gondii reservoir and it has potential value as a sentinel of T. gondii in environmental substrates. Toxoplasma gondii was associated with female sex (P < 0·001) and with relatively heavy infections by Eimeria stiedae (P = 0·036). It was not associated with the intensity of coccidial oocysts, the severity of myxomatosis caused by the virus Myxomatosis cuniculi, the intensity of roundworm eggs, the year or season, rabbit age or distance from farm buildings. Coinfections could have been affected by gestational down regulation of type 1 T helper cells. A sudden influx or release of T. gondii oocysts might have occurred. This is the first report of T. gondii in any wild herbivore in Scotland and also the first report of lapine T. gondii as a coinfection with E. stiedae, M. cuniculi and helminths.

Seroprevalence of anti-Toxoplasma IgG and IgM among individuals who were referred to medical laboratories in Mazandaran province, northern Iran.

Toxoplasma gondii (T. gondii) is a protozoan parasite that can cause toxoplasmosis in humans. However, there is no current data regarding Toxoplasma infection among individuals who were referred to medical laboratories in Mazandaran province (northern Iran). Therefore, we performed a population-based study of Toxoplasma seroprevalence in this region. A total of 1832 sera samples (from 654 men and 1178 women) were collected from people who were referred to medical laboratories in different cities throughout Mazandaran province between March and July 2012. The serum titers of anti-T. gondii IgG and IgM were measured using enzyme-linked immunosorbent assays. The seroprevalence of anti-Toxoplasma IgG was 55.5%; and 14.4% of the positive samples were seropositive for anti-Toxoplasma IgM. The highest seroprevalence was observed among people who were >50 years old (90.6%), and the lowest seroprevalence was observed among children who were 0-9 years old (9.4%; P<0.001). There was no significant difference in the seroprevalences for each sex in the study population. However, a regional sex-specific difference in seroprevalence was observed between men (54.1%) and women (70.6%; P=0.003) in the western cities of Mazandaran. As the seroprevalence of T. gondii in western and eastern Mazandaran was higher than that in the central cities, there is a need to evaluate the nature of the infection chain in these areas.

Seroprevalance Differences of Toxoplasma Between Syrian Refugees Pregnants and Indigenous Turkish Pregnants in Kahramanmaraş

In this study, we aimed to compare the Syrian refugees and resident Turkish pregnant population in terms of Toxoplasma seroprevalence. Data acquired from Kahramanmaraş Necip Fazıl City Hospital Department of Obstetrics and Gynecology between 2012 and 2013 were analyzed retrospectively. Results of 7201 Toxoplasma IgM tests and 4113 Toxoplasma IgG tests were evaluated. For 2012 and 2013 Toxoplasma IgM seropositivity was found in Syrian refugees 4.76% and 4.84% respectively in our study. In the same population Toxoplasma IgG seropositivity rates were 80% and 62.6%, respectively. Toxoplasma IgM seropositivity rates for the native peoples in Turkey in 2012 and 2013 was 1.96% and 2.34%, while in the same population Toxoplasma IgG seropositivity was detected 49.7% and 45.7% respectively. Toxoplasma IgM seropositivity was statistically higher in Syrian refugees for each year (p <0.001 and 0.019, respectively). Toxoplasma IgG seropositivity of Syrian refugees was statistically higher (p <0.001 and <0.001 respectively). Since it was found in our study that toxoplasma seropositivity rates of Syrian refugees living in the region of Kahramanmaraş were statistically higher than the rates of local inhabitants, we consider that this condition should be taken into account in the follow-ups of Syrian pregnant refugees outnumbering in Kahramanmaraş and its vicinity.

Seroprevalence of Toxoplasma, Rubella, and Cytomegalovirus among pregnant women in Van.

Objective:To determine the seroprevalence of anti-Toxoplasma, anti-Rubella, and anti-Cytomegalovirus (CMV) antibodies among pregnant women receiving prenatal care at Van Training and Research Hospital.Materials and Methods:In developing countries, various infectious agents encountered in the gestational period are important because they influence both maternal and fetal health. Among these, Toxoplasma gondii, Rubella and CMV are quite prevalent. In the present study, anti-Toxoplasma, anti-Rubella and anti-CMV antibodies were analyzed in the serum samples obtained from women receiving prenatal care at Van Training and Research Hospital between June 2012 and July 2013, and positive serum samples were retrospectively evaluated. Anti-Toxoplasma, anti-Rubella and anti-CMV antibodies were analyzed using ELISA with Cobas 4000 e411 (Roche, Germany) and Architect i2000SR (Abbott Diagnostics, Germany) analyzers.Results:Over the course of the study period, the results of a total of 9809 patients were investigated in terms of anti-Toxoplasma, anti-Rubella, and anti-CMV antibodies. Anti-Toxoplasma, anti-Rubella, and anti-CMV IgM and IgG antibody positivity rates were 1.1%, 0.5% and 2.6%, and 37.6%, 86.5% and 100%, respectively.Conclusion:Anti-Toxoplasma IgG antibody positivity rates determined in the present study were lower as compared with the results of the other studies reported from Turkey. However, CMV IgM and IgG antibody positivity rates were be higher as compared with those reported in the literature.

Seroprevalence of Toxoplasma and Rubella in childbearing age women

Ozet Abstract Amac: Bu calismanin amaci, iki yillik donemde dogurgan yastaki kadinlarda konjenital enfeksiyonlara yol acabilme potansiyeline sahip Toksoplazma gondii ve Rubella virusune karsi olusan antikorlarin seroprevalansini arastirmakti. Yontem: Bu calismaya 01.01.2012 01.01.2014 tarihleri arasinda hastanemize basvuran dogurgan yastaki kadinlar dahil edildi. Hasta serumlarindaki Toksoplazma ve Rubella antikorlari VIDAS (BioMerieux, France) kitleri kullanarak enzim immunoassay (EIA) yontemiyle olculdu. Test sonuclari retrospektif olarak degerlendirildi. Bulgular: Rubella IgM antikorlarinda (n=15) %0.5 oraninda pozitiflik saptanirken, IgG antikorlarinda (n=451) %95.8 oraninda bulunmustur. Toksoplazma IgM antikorlarinda (n=38) %1.2 oraninda pozitiflik saptanirken, IgG antikorlarinda (n=158) bu oran %35.5 olarak belirlenmistir. Sonuc: Bolgemizde dogurgan cagdaki kadinlarda saptanan yuksek toksoplazma seronegatifliginden dolayi toksoplazma icin rutin taramaya ihtiyac bulunmaktadir. Ancak tum duyarli kadinlarin toksoplazma enfeksiyonlarindan korunma ve kontrolu acisindan egitimi konjenital enfeksiyon riskini azaltabilir. Saptadigimiz rubella seropozitiflik oranlarinin yuksek olmasi nedeniyle rubella icin rutin taramanin mutlak ihtiyac olmadigini dusunmekteyiz. Objective: The aim of this study was to investigate seroprevalence of antibodies against Rubella virus and Toxoplasma gondii, which may cause congenital infections in childbearing age women in a period of two years. Method: This study included pregnant and childbearing age women who had admitted to our hospital in the period between 01.01.2012 and 01.01.2014. Toxoplasma and Rubella antibodies tests in sera of patients were tested with an enzyme immunoassay (EIA) method using VIDAS (BioMerieux, France) kits. Test results were evaluated retrospectively. Results: Rubella IgM antibodies (n = 15) were detected as positive in 0.5% of samples and the IgG antibody seropositivity rate (n = 451) was found to be 95.8%. The Toxoplasma IgM antibody positivity rate was 1.2% (n= 38) and the IgG seropositivity was 35.5% (n = 158). Conclusion: Routine screening for toxoplasma seropositivity may be needed due to high seronegativity in among women of childbearing age in our region. Additionally, education of all susceptible women about protection and control of toxoplasma infection might be useful in decreasing the risk of congenital infections. However, routine screening for Rubella is considered unnecessary due to the high seropositivity rate.

Seroprevalence of Toxoplasma among HIV infected and HIV non-infected individuals in North India

ObjectiveTo determine the seroprevalence of Toxoplasma infection in the HIV infected and HIV non-infected individuals in our region, including antenatal women. MethodsFive mL of blood sample was collected from a total of 1 181 individuals aged 12 years and above. These included 661 (55.9%) from HIV positive patients and 520 (44.1%) from HIV negative individuals. A total of 238 samples out of the 520 HIV negative patients were collected from the antenatal women. Demographic profile of the subjects was recorded. Immunoglobulin G ELISA was performed for all the samples, while only the samples received from antenatal women were tested by immunoglobulin M capture ELISA. ResultsSeroprevalence among HIV infected and non-infected was found to be 21.3% (95% confidence interval = 18.4%−24.6%) and 14.2% (95% confidence interval = 11.5%−17.5%), respectively. The difference was statistically significant (P = 0.003). No significant gender differences were found. Seroprevalence increased from 9.1% to 30% with increasing age in the HIV infected patients. Only 2 (0.84%) samples of antenatal women were positive for immunoglobulin M capture ELSIA, while one sample was equivocally reactive. ConclusionsSeroprevalence of latent toxoplasmosis in our region is moderately high, particularly in the HIV infected patients, exposing them to the risk of reactivation. This suggests that serologic testing of all HIV infected patients is essential to initiate Toxoplasma prophylaxis. Similarly, screening for active Toxoplasma gondii infection during antenatal care and preventive education is essential to prevent and minimize congenital toxoplasmosis.

Seroprevalence of Toxoplasma gondii Infection in Patients of Intensive Care Unit in China: A Hospital Based Study.

The objective of this study was to estimate the seroprevalence of Toxoplasma gondii infection in 394 patients of intensive care unit (ICU) in a hospital between April 2010 and March 2012 and analyze the association between T. gondii infection and ICU patients according to the species of disease. Toxoplasma serology was evaluated by ELISA method using a commercially available kit. Data of patients were obtained from the patients, informants, and medical examination records. Seventy-four (18.78%) of 394 patients were positive for anti-T. gondii IgG antibodies demonstrating latent infection. Of these, the highest T. gondii seroprevalence was found in the age group of 31–45 years (27.45%), and the lowest was found in the age group of <30 years (12.5%). In addition, females (21.6%) had a higher seroprevalence than males (18.36%). With respect to the species of disease, the patients with kidney diseases (57.14%), lung diseases (27.84%), and brain diseases (24%) had high T. gondii seroprevalence. The present study represents the first survey of T. gondii seroprevalence in ICU patients in China, revealing an 18.78% seropositivity. Considering the particularities of ICU patients, molecular identification, genetic characterization, and diagnosis of T. gondii should be considered in future study.

Meat Juice Serology and Improved Food Chain Information as Control Tools for Pork-Related Public Health Hazards.

The seroprevalence of Salmonella spp., pathogenic Yersinia spp., Toxoplasma gondii and Trichinella spp. was studied in 1353 finishing pigs from 259 farms that were allocated according to farm types: large fattening farms (≥ 1000 pig places), small fattening farms (< 1000 pig places) and farrow-to-finish farms. The antibodies were analysed with commercial ELISA kits in meat juice samples that were collected at Finnish slaughterhouses. Salmonella antibodies were rare (3% of pigs, 14% of farms) when the cut-off optical density (OD) value 0.2 was used. Antibodies to pathogenic Yersinia spp. and T. gondii were detected in 57% of pigs and 85% of farms (OD ≥ 0.3) and in 3% of pigs and 9% of farms (OD ≥ 0.15), respectively. No antibodies to Trichinella spp. were detected (OD ≥ 0.3). The European Food Safety Authority (EFSA) considers Salmonella spp., Yersinia enterocolitica, T. gondii and Trichinella spp. as the most relevant biological hazards in the context of meat inspection of pigs. The seroprevalence of these important zoonotic pathogens was low in Finland, except that of Yersinia. The seroprevalence of Toxoplasma was significantly higher in pigs originating from small-scale fattening farms (P < 0.05). Strong positive correlation was observed at the animal level between Salmonella and Yersinia seropositivity and between Salmonella and Toxoplasma seropositivity (P < 0.05). We suggest that these results reflect the level and importance of biosecurity measures applied on the farms. Meat juice serology at slaughter is a useful tool for targeting measures to control these pathogens. The information obtained from analyses should be used as part of the food chain information (FCI).

Seroprevalence of Toxoplasma gondii antibodies and associated risk factors among children in Shandong and Jilin provinces, China

Infection by the protozoan parasite Toxoplasma gondii is generally prevalent in animals and humans worldwide. However, little is known about T. gondii infection among children in China. Thus, the present study was conducted to detect the seroprevalence of T. gondii infection and estimate associated risk factors among children in eastern China. A cross-sectional study of 1500 children from three cities (Changchun, Qingdao, Weihai) was conducted between May 2013 and July 2014 to estimate the seroprevalence and potential risk factors associated with acquiring T. gondii infection in children in China. Demographic and blood samples were collected, and anti-T. gondii IgG and IgM antibodies were measured by ELISA. The mean age of the 1500 children participating in the study was 9.03 years (range 1-18). The overall seroprevalence of Toxoplasma infection was 15.13%, of which 13.13% were positive for only anti-Toxoplasma IgG antibodies, 3.13% were positive for both anti-Toxoplasma IgG and IgM antibodies and 2.00% were IgM positive and IgG negative. Moreover, raising cats at home (OR=1.94, 95% CI=1.288-2.912, P=0.002) and hand washing habits (OR=0.38, 95% CI=0.230-0.635, P<0.001) were estimated to be risk and protective factors associated with Toxoplasma seroprevalence, respectively. The present study revealed for the first time that children's infection with T. gondii is common in eastern China. The present data indicate a need to implement methods of prevention and control measures against Toxoplasma infection in China.

Genetic characterization of Toxoplasma gondii isolates and toxoplasmosis seroprevalence in stray cats of İzmir, Turkey.

Currently, some Toxoplasma gondii genotypes are being associated with serious clinical presentations. A recent report showing the Africa 1 genotype in two local congenital toxoplasmosis cases acquired in Turkey formed the basis of this study because atypical Africa 1 genotype is most frequently detected in animals and patients from sub-Saharan Africa. Since stray cats are considered as the linkage between wild life and urban life in T. gondii transmission, the present study aimed to isolate and characterize T. gondii strains circulating in stray cats of İzmir (Western Turkey). A secondary objective was to determine toxoplasmosis seroprevalence in this cat population. Tissues obtained from 100 deceased stray cats were bioassayed and isolated strains were genotyped using 15 microsatellite markers. In addition, toxoplasmosis seroprevalence was analyzed in 1121 cat sera collected from several large veterinary clinics in İzmir. Among the 22 isolates, 19 were Type II (86.3%), two were Type III (9%) and one was Africa 1 genotype (4.5%). The overall seropositivity rates in cats were 42–48% and 33.4–34.4% according to IFA and ELISA, respectively. Seroprevalence in deceased cats was significantly higher than in healthy cats (P = 0.0033). Finding both the major clonal Type II lineage together with the Type III lineage also found in Middle East, and an atypical genotype, Africa 1 appears consistent with the specific geographic location of Turkey between three continents and raises the possibility of transportation of these strains between continents through trade routes or long distance migratory birds. In addition, the first large study of toxoplasma seroprevalence in a stray cat population was also reported. The relatively high seropositivity rates and the variety of T. gondii genotypes confirm the local stray cat population as a risk factor for human toxoplasmosis in İzmir.

Seroprevalence of Toxoplasma gondii and Bartonella henselase infection in stray cats of the Daejeon City, Korea

Abstract : In this study, the seroprevalence of Toxoplasma (T.) gondii and Bartonella (B.) henselae infection amongstray cats in Daejeon City, Korea was surveyed. A total of seven samples were positive (7/118, 5.93%) for T. gondiiincluding three samples from female cats (3/58, 5.2%) and four samples from male cats (4/60, 6.7%). There was nosignificant difference between the genders. A total 22 samples (22/118, 18.6%) were positive for B. henselae; ninewere from females and 13 were from males. There was no significant difference between genders. Nineteen sampleshad a titer of 1 : 50, two samples had a titer of 1 : 100, and one sample had a titer of 1 : 200. The present studyis the first to use serological tests to analyze B. henselae prevalence among stray cats in Korea.Keywords : Bartonella henselae, cat, Toxoplasma gondii Introduction Toxoplasma (T.) gondii is a worldwide endemic intracellu-lar parasite that infects most warm-blooded vertebratesincluding cat, and human [12, 17, 18]. It is generally knownthat cats are a major spreader of this zoonotic agent by eat-ing or direct contacting with feces, soil, food or water con-taminated oocysts or tissue cysts of T. gondii over a period of1~2 weeks [5]. Cat is the only animal that excretes resistantoocysts into the environment and a single cat may excrete 10million oocysts [15]. Recently, several reports on the preva-lence of T. gondii infection in feral cats in local areas, includ-ing Gyeonggi province [9], Seoul [13] and Daejeon [11] havebeen published.A syndrome of fever, malasise, and regional lymphadenop-athy in people that was frequently associated with contactwith kittens or cats was called cat scratch disease (CDS),which is a zoonosis caused by Bartonella(B.) henselase [2, 4,6]. The natural infection with B. henselase is usually asymp-tomatic, or mild clinical signs such as lymphoadenopathy, sto-matitis, renal, and neurological disease in cats [7, 8]. Infectedcats, even if asymptomatic, may be highly bacteremic forseveral months, and can be a risk factor for human infection[3, 6]. In Korea, large numbers of stray cats become a con-troversial issue, due to their uncontrolled overpopulation,public health, animal welfare [11, 19]. Also, they disrupt peo-ple’s sleep, traffic accidents, and this has been a serious issuesince 2000 [12]. The purpose of this study is re-evaluate the seroprevalenceof T. gondii and B. henselae which are zoonotic pathogenthat can be spread by cats in Daejeon by Enzyme-linkedimmunosorbent assay (ELISA) and indirect immunofluores-cence antibody test (IFAT).

Seroepidemiology of Toxoplasma gondii infection in Bai and Han ethnic groups in southwestern China.

Eating raw pork and/or liver is a custom of the Bai ethnic group in China. Most people living in Dali Bai Autonomous Prefecture, Yunnan Province, southwestern China are of Bai ethnicity. Little is known of the seroprevalence of Toxoplasma gondii in Bai and Han ethnic populations in this region. In the present survey, a total of 555 and 595 blood samples were obtained from Bai and Han ethnic groups in Dali urban and rural areas, respectively. Enzyme-linked immunosorbent assay was performed to examine T. gondii IgG antibodies. Total positive rate of anti-T. gondii IgG in Bai and Han groups in this region was 21·6% (248/1150). The total seroprevalence of T. gondii was significantly higher in the Bai ethnic group (32·3%, 179/555) than in the Han ethnic group (11·6%, 69/595) (P < 0·01). The results of statistical analysis indicated that there was no significant difference between cat feeding/non-cat feeding groups in the Bai ethnic group, the most important risk factor was consumption of raw pork and/or liver for the Bai group, but feeding a cat may be the main route of T. gondii infection for the Han group. Therefore, it is essential to implement integrated strategies to prevent and control T. gondii infection in this unique region of the world.

Toxoplasma Seroprevalence in Healthy Voluntary Blood Donors from Blood Bank of Baghdad

In this study (300) blood samples were collected from healthy volunteer at nationaltransfusion center, ministry of health, republic of Iraq, was examined for anti-Toxoplasmagondii antibodies by enzyme linked immunosorbent assay. The seroprevalence of anti-Toxoplasma gondii total IgG, IgM antibodies were 85 (56.6%), 40 (26.6%) respectively.While positive rate for IgG, IgM in female and male were 65 (43.3%), 35 (23.3%) and 20(13.3%), 5 (3.3%) respectively. The high positive rate of IgG and IgM appear in femle whoage rated between (21-30) and (31-40) years old, were 27 (25.7%), 7 (15.5%) respectively.Also rate of toxoplasmosis in married women greater than married men 27 (28.4%), 2 (1.9%).The same things for women cats breed, the rate of IgG and IgM was 24(44.4), higher thanmen who breed cats.

Seroprevalence of Neospora caninum and Toxoplasma gondii infections in aborted cattle in Hamedan, Iran

The aim of current study was to assess the seroprevalence of Neospora (N.) caninum and Toxoplasma (T.) gondii infections in aborted cattle and subsequent estimation of role of these parasites in cattle abortion in Hamedan province, Iran. Blood samples (n=85) of aborted cattle were collected from different locations of Hamedan province for a period of two years from January, 2010 to December, 2012. All the samples were evaluated for the presence of IgG-antibodies against N. caninum and T. gondii using Enzyme Linked Immuno Sorbent Assay (ELISA). The results showed that 61.2% (n=52/85), 5.9% (n=5/85) and 3.5% (n=3/85) animals were positive for N. caninum, T. gondii and co-infection of these two, respectively. There was no significant correlation between seroprevalence rates, age groups and breeding (p>0.05). However, a significant difference was found between T. gondii infection and the type of cattle (p=0.05), unlike to N. caninum (p=0.52). This is the first report of N. caninum and T. gondii co-infection in cattle in Iran. Although the rate of T. gondii infection was lower but this parasite might partly be responsible to be transmitted to humans. Further investigations and appropriate control strategies in management of cattle farms are highly recommended.

Toxoplasma gondii and Neospora caninum seroprevalence in dairy sheep and goats mixed stock farming

Toxoplasma and Neospora infections are important causes of abortions and economic losses in animal production. Mixed stock farming of sheep and goats is a common practice in Mediterranean countries and could serve as a suitable model for the evaluation of differences between the two animal species regarding parasitic infections. In order to investigate the seroprevalence of T. gondii and N. caninum among flocks of small ruminants in Greece and to evaluate any prevalence difference between sheep and goats kept in mixed flocks, 833 sera samples (458 sheep and 375 goats) from 50 mixed flocks in different areas of the country were examined by ELISA for the detection of specific antibodies. Specific IgG against T. gondii were detected in 53.71% and 61.3% and against N. caninum in 16.8% and 6.9% of the sheep and goats, respectively. Goats had higher Toxoplasma seroprevalence than sheep (p<0.05), while sheep had higher Neospora seroprevalence than goats (p<0.05). The present study is the first report world wide, on the seroprevalence of T. gondii and N. caninum in sheep and goats that are kept together in mixed flocks.

Toxoplasmosis seroprevalence in urban rodents: a survey in Niamey, Niger

A serological survey of Toxoplasma gondii was conducted on 766 domestic and peridomestic rodents from 46 trapping sites throughout the city of Niamey, Niger. A low seroprevalence was found over the whole town with only 1.96% of the rodents found seropositive. However, differences between species were important, ranging from less than 2% in truly commensal Mastomys natalensis, Rattus rattus and Mus musculus, while garden-associated Arvicanthis niloticus displayed 9.1% of seropositive individuals. This is in line with previous studies on tropical rodents - that we reviewed here - which altogether show that Toxoplasma seroprevalence in rodent is highly variable, depending on many factors such as locality and/or species. Moreover, although we were not able to decipher statistically between habitat or species effect, such a contrast between Nile grass rats and the other rodent species points towards a potentially important role of environmental toxoplasmic infection. This would deserve to be further scrutinised since intra-city irrigated cultures are extending in Niamey, thus potentially increasing Toxoplasma circulation in this yet semi-arid region. As far as we are aware of, our study is one of the rare surveys of its kind performed in Sub-Saharan Africa and the first one ever conducted in the Sahel.

Toxoplasmosis seroprevalence in urban rodents: a survey in Niamey, Niger

A serological survey of Toxoplasma gondii was conducted on 766 domestic and peridomestic rodents from 46 trapping sites throughout the city of Niamey, Niger. A low seroprevalence was found over the whole town with only 1.96% of the rodents found seropositive. However, differences between species were important, ranging from less than 2% in truly commensal Mastomys natalensis, Rattus rattus and Mus musculus, while garden-associated Arvicanthis niloticus displayed 9.1% of seropositive individuals. This is in line with previous studies on tropical rodents--that we reviewed here--which altogether show that Toxoplasma seroprevalence in rodent is highly variable, depending on many factors such as locality and/or species. Moreover, although we were not able to decipher statistically between habitat or species effect, such a contrast between Nile grass rats and the other rodent species points towards a potentially important role of environmental toxoplasmic infection. This would deserve to be further scrutinised since intra-city irrigated cultures are extending in Niamey, thus potentially increasing Toxoplasma circulation in this yet semi-arid region. As far as we are aware of, our study is one of the rare surveys of its kind performed in Sub-Saharan Africa and the first one ever conducted in the Sahel.

Wildlife disease ecology in changing landscapes: Mesopredator release and toxoplasmosis

Changing ecosystem dynamics are increasing the threat of disease epidemics arising in wildlife populations. Several recent disease outbreaks have highlighted the critical need for understanding pathogen dynamics, including the role host densities play in disease transmission. In Australia, introduced feral cats are of immense concern because of the risk they pose to native wildlife through predation and competition. They are also the only known definitive host of the coccidian parasite, Toxoplasma gondii, the population-level impacts of which are unknown in any species. Australia's native wildlife have not evolved in the presence of cats or their parasites, and feral cats may be linked with several native mammal declines and extinctions. In Tasmania there is emerging evidence that feral cat populations are increasing following wide-ranging and extensive declines in the apex predator, the Tasmanian devil, from a consistently fatal transmissible cancer. We assess whether feral cat density is associated with the seroprevalence of T. gondii in native wildlife to determine whether an increasing population of feral cats may correspond to an increased level of risk to naive native intermediate hosts. We found evidence that seroprevalence of T. gondii in Tasmanian pademelons was lower in the north-west of Tasmania than in the north-east and central regions where cat density was higher. Also, samples obtained from road-killed animals had significantly higher seroprevalence of T. gondii than those from culled individuals, suggesting there may be behavioural differences associated with infection. In addition, seroprevalence in different trophic levels was assessed to determine whether position in the food-web influences exposure risk. Higher order carnivores had significantly higher seroprevalence than medium-sized browser species. The highest seroprevalence observed in an intermediate host was 71% in spotted-tailed quolls (Dasyurus maculatus), the largest mammalian mesopredator, in areas of low cat density. Mesopredator release of cats may be a significant issue for native species conservation, potentially affecting the population viability of many endangered species.