Acute Toxoplasma Infection Research Articles

TGF-β1 levels and intraocular tissue alterations in mice infected with a virulent type I RH Toxoplasma gondii strain

Toxoplasmosis is generally self-limiting in healthy adults but it may cause toxoplasmic retinochoroiditis in cases of congenital infection leading to blindness. The importance of host genetics in determining disease severity in ocular toxoplasmosis has been shown in different inbred mouse strains using low-virulence toxoplasma strain. In this study, we studied intraocular immune response and tissue alterations in the genetically resistant BALB/c and susceptible MF1 mice infected with a virulent type I RH Toxoplasma gondii strain by intravitreal route. We observed a significant up-regulation of IFN-γ and TNF-α to >2200 pg/ml and >300 pg/ml respectively in the blood of both BALB/c and MF1mice during the early stages of post intraocular infection (p < 0.01) but the levels dropped sharply to normal during the late stages of the infection on day 26. The cytokine levels detected were higher in the MF1 mice compared with the BALB/c mice and a relatively higher levels were observed in the aqueous humour (AqH) than in the blood of both group of mice. The TGF-β1 level in the blood and AqH of BALB/c mice remained low throughout the infection period compared with MF1 mice which showed gradual increase to 50 pg/ml in the blood and AqH during the early stages of infection which then further increased 2-fold–132 pg/ml on day 11 (p < 0.01) and remained high till the last day of observation on day 26 except that the TGF-β1 level in AqH dropped sharply to normal level.In summary, our results support that TGF-β1 may down-regulate the effector functions of anti-Toxoplasma cellular immunity during acute toxoplasmosis. We document that a mild Th1 pro-inflammatory response in the BALB/c mice with high IFN-γ and TNF-α and, low TGF-β1 levels during the early stages of infection may have contributed to an effective cellular immune response leading to lower morbidity, mortality and less ocular tissue damage. However in the MF1 mice, a significantly high TGF-β1 level in the blood as well as in the AqH during the acute intra-ocular toxoplasma infection may have adversely interfered with an effective cellular immune response leading to an increased mortality and extensive ocular tissue damage with parasite tachyzoites observed in the pigment epithelium layers.

The Prevalence of Toxoplasma gondii in Hemodialysis Patients

The Prevalence of Toxoplasma gondii in Hemodialysis Patients

Parasitic Infections in Solid Organ Transplantation

Parasitic Infections in Solid Organ Transplantation

CongenitalToxoplasmaInfection: Monthly Prenatal Screening Decreases Transmission Rate and Improves Clinical Outcome at Age 3 Years

Toxoplasma infection during pregnancy exposes the fetus to risks of congenital infection and sequelae that depend heavily on gestational age (GA) at time of infection. Accurate risk estimates by GA are necessary to counsel parents and improve clinical decisions. We analyzed data from pregnant women diagnosed with acute Toxoplasma infection in Lyon (France) from 1987 to 2008 and assessed how the risks of congenital toxoplasmosis and of clinical signs at age 3 years vary depending on GA at the time of maternal infection. Among 2048 mother-infant pairs, 93.2% of mothers received prenatal treatment and 513 (24.7%) fetuses were infected. Because of a significant reduction in risk since 1992 when monthly screening was introduced (59.4% vs 46.6% at 26 GA weeks; P = .038), probabilities of infection were estimated on the basis of maternal infections diagnosed after mid-1992 (n = 1624). Probabilities of congenital infection were <10% for maternal infections before 12 weeks of gestation, rose to 20.0% at 19 weeks, and then continued increasing to 52.3% and almost 70% at 28 and 39 GA weeks, respectively. Because of a significant reduction in risk of clinical signs of congenital toxoplasmosis in infected children born from mothers diagnosed after 1995 when polymerase chain reaction testing on amniotic fluid was initiated (87/794 vs 46/1150; P = .012), probabilities of clinical signs at 3 years were estimated based on 1015 maternal infections diagnosed after 1995 including 207 infected children, with symptoms in 46 (22.2%). These analyses demonstrated that introduction of monthly prenatal screening and improvement in antenatal diagnosis were associated with a significant reduction in the rate of congenital infection and a better outcome at 3 years of age in infected children. Our updated estimates will improve individual management and counseling in areas where genotype II Toxoplasma is predominant.

Evaluation of Serological Prenatal Screening to Detect Toxoplasma gondii Infections in Austria

Background: In Austria, a nationally mandated prenatal serological congenital toxoplasmosis screening program was introduced in 1974 in response to a high incidence of 7.8 per 1,000 infected infants. Maternal prenatal recognition of acute gestational infection and early treatment of infants with congenital infection are important because prenatal and accurate postnatal antibiotic therapy improves the outcomes of infected infants. Objective: To determine the impact of additional maternal and/or fetal cord blood serology at birth on improving current prenatal maternal screening in detecting congenital toxoplasmosis. Methods: In this prospective observational study, 5,545 consecutive women were included over a 19-month period. Routine prenatal maternal toxoplasmosis serology screening was performed along with additional cord blood serology screening at delivery. Fetal cord blood serology included Sabin-Feldman dye and IgM immunosorbent agglutination assay testing. Results: Based on the initial prenatal maternal screening serology results, there was evidence of a prior chronic infection manifest in 1,830 (33.0%) women and 3,708 (66.9%) were not infected. Seven (0.13%) were diagnosed with acute toxoplasma infection based on seroconversion. Of these, 4 manifested transmission, and 3 did not. Of the seven infected women, routine prenatal maternal screening identified acute infection in only 2 of the women, 1 of whom had an infected fetus with abnormal prenatal ultrasound. Fetal cord blood serology screening identified an additional 5 women, 3 with infected fetuses. Conclusions: Identification of Toxoplasma gondii infection by prenatal maternal serological testing is significantly improved by the addition of maternal and/or fetal serological testing at birth.

Prevalence of Toxoplasma gondii infection in antenatal population in Menoufia governorate, Egypt

Knowledge of the prevalence of Toxoplasma gondii infection in pregnant women would be a valuable approach for planning appropriate preventive strategies. However, no enough data currently exist as to the magnitude of T. gondii infection among pregnant women in Egypt. In view of paucity of reports on this issue, the current cross–sectional study aimed to determine the rate of T. gondii infection and maternal–fetal transmission in antenatal population in Menoufia governorate, Egypt. Out of 323 pregnant women who were screened for Toxoplasma-specific IgG and IgM antibodies with ELFA, 218 samples were IgG seropositive, of which, 9 samples were IgM seropositive. Therefore, seropositivity rates of 67.5% (95% CI: 62.39%, 72.61%), and 2.8% (95% CI: 1%, 4.6%) for IgG and IgM, respectively were found. Analysis of serological patterns revealed that a large proportion of subjects were immune to Toxoplasma infection (IgG+/IgM−), as prevalence of chronic infection was 64.7% (209 cases), and 32.5% of cases were susceptible to primary infection (IgG−/IgM−). Meanwhile, the rate of probable acute Toxoplasma infection (IgG+/IgM+) was 2.8%, with one case (0.3%) confirmed for recent infection, as she had low avidity index with positive amniotic fluid analysis with both PCR and mouse inoculation. Significant relations were seen between Toxoplasma-specific IgG and knowledge about transmission modes, consumption of milk/milk products and unwashed raw vegetable/fruit, hand hygiene, contact with soil and farm animals. In conclusion, we reported high prevalence for T. gondii infection among antenatal population in Menoufia governorate. Thus, the susceptibility for toxoplasmosis is relatively low. Sources of infection revealed herein might represent potential threats for primary infection in seronegative women. Accordingly, there is urgent need for implementation of health education programs as an appropriate approach for prevention.

Toxoplasma gondii infection: relationship between seroprevalence and risk factors among primary schoolchildren in the capital areas of Democratic Republic of São Tomé and Príncipe, West Africa

BackgroundThe status of Toxoplasma gondii infection among primary schoolchildren (PSC) of the Democratic Republic of São Tomé and Príncipe (DRSTP), West Africa, remains unknown to date.MethodsA serologic survey and risk factors associated T. gondii infection among PSC in the DRSTP was assessed by the latex agglutination (LA) test and a questionnaire interview including parents’ occupation, various uncomfortable symptoms, histories of eating raw or undercooked food, drinking unboiled water, and raising pets, was conducted in October 2010. Schoolchildren from 4 primary schools located in the capital areas were selected, in total 255 serum samples were obtained by venipuncture, of which 123 serum samples were obtained from boys (9.8 ± 1.4 yrs) and 132 serum samples were obtained from girls (9.7 ± 1.3 yrs).ResultsThe overall seroprevalence of T. gondii infection was 63.1% (161/255). No significant gender difference in seroprevalence was found between boys (62.6%, 77/123) and girls (63.6%, 84/132) (p = 0.9). The older age group of 10 years had insignificantly higher seroprevalence (69.9%, 58/83) than that of the younger age group of 8 year olds (67.7%, 21/31) (p = 0.8). It was noteworthy that the majority of seropositive PSC (75.8%, 122/161) had high LA titers of ≥1: 1024, indirectly indicating acute or repeated Toxoplasma infection. Parents whose jobs were non-skilled workers (73.1%) showed significantly higher seroprevalence than that of semiskilled- (53.9%) or skilled workers (48.8%) (p < 0.05). Children who had a history of raising cats also showed significantly higher seroprevalence than those who did not (p < 0.001).Children who claimed to have had recent ocular manifestation or headache, i.e. within 1 month, seemed to have insignificantly higher seroprevalence than those who did not (p > 0.05).ConclusionsParents’ educational level and cats kept indoors seemed to be the high risk factors for PSC in acquisition of T. gondii infection. While, ocular manifestation and/or headache of PSC should be checked for the possibility of being T. gondii elicited. Measures such as improving environmental hygiene and intensive educational intervention to both PSC and their parents should be performed immediately so as to reduce T. gondii infection of DRSTP inhabitants including PSC and adults.

Retrospective Evaluation of the Results of Women Patients of Childbearing Age Investigated at a Microbiology Laboratory for Screening Toxoplasma gondii, in Antalya

Infection with Toxoplasma gondii usually does not cause clinical symptoms in humans, but an acute infection during pregnancy can lead to congenital toxoplasmosis. Infection in early pregnancy may cause abortion, stillbirth or serious abnormalities of the fetus. In this study, determination of T. gondii seroprevalence among women of childbearing age who presented to our hospital's clinics is aimed. Toxoplasma IgM antibodies were investigated in 5013 sera and Toxoplasma IgG in 2986 sera of women between 15-49 years, in our hospital central laboratory, between 01 November 2008 and 31 August 2010. Eighty-nine (1.8%) seras were detected positive for Toxoplasma IgM and 968 (32.4%) for Toxoplasma IgG antibodies. It has been determined that 67.6% of women in the province of Antalya and its surroundings are susceptible to acute Toxoplasma infection during childbearing age and their babies are an at risk group for congenital toxoplasmosis.

Higher Extraversion and Lower Conscientiousness in Humans Infected with Toxoplasma

Toxoplasmosis is associated with specific differences in the personality of infected subjects relative to non–infected subjects. These differences are usually considered to be a side effect of the manipulative activity of the parasite aimed to increase the probability of its transmission from the intermediate host to the definitive host by predation. The personality of infected subjects was studied mostly using the Cattell's questionnaire. However, this questionnaire is now considered outdated and has been mostly substituted with the Neuroticism–Extraversion–Openness Personality Inventory—Revised (NEO–PI–R) questionnaire in clinical practice. Here, we searched for the association between toxoplasmosis and the personality by screening a population of students with the NEO–PI–R questionnaire. We found that Toxoplasma–infected male and female students had significantly higher extraversion and lower conscientiousness. The conscientiousness negatively correlated with the length of infection in men, which suggested that the toxoplasmosis associated differences were more probably the result of slow cumulative changes induced by latent toxoplasmosis, rather than transient side effect of acute Toxoplasma infection. The existence of this correlation also supported (but of course not proved) the hypothesis that Toxoplasma infection influenced the personality, rather than the hypothesis that the personality influenced the probability of the infection. Copyright © 2011 John Wiley &amp; Sons, Ltd.

Toxoplasmosis in a post-transplant bronchoalveolar lavage: A case report

Toxoplasma gondii usually causes an asymptomatic and then latent infection in human adults; however, a potentially fatal disseminated form can occur in immunocompromised patients. Given that the diagnosis of acute Toxoplasma infection, as opposed to latent disease, relies on finding direct evidence of T. gondii infection in tissue, pathologic examination is critical. There have only been a few reports describing the cytomorphology of Toxoplasma in exfoliative cytology, and no reports of the findings in Thin Prep. In this report, we describe a fatal case of toxoplasmosis in a cardiac transplant patient that was diagnosed by respiratory cytopathology. Although the extracellular organisms were well visualized on the Wright-Giemsa stained cytospin, they were only faintly seen on the Pap-stained cytospin trapped within mucin and were not easily appreciated on the ThinPrep slides nor the H&E stained cell block sections. An immunohistochemical stain for Toxoplasma performed on the cell block was strongly positive, and an autopsy performed on the patient confirmed disseminated infection. Our case illustrates that the diagnosis of Toxoplasma in exfoliative cytology specimens can be challenging since organisms are not well visualized on ThinPrep or Pap-stained material; therefore, Wright-Giemsa stained material can be particularly helpful.

Toxoplasmosis among the pregnant women attending a Saudi maternity hospital: seroprevalence and possible risk factors

In a cross-sectional study to determine the seroprevalence of, and possible risk factors for, Toxoplasma gondii infection in the pregnant women of Saudi Arabia, all of the pregnant Saudi women attending the Al Ahsa Maternity Hospital over a 1-year period were invited to participate. In an interview with each subject, the relevant socio-demographic data and information on housing conditions, previous obstetric history and possible risk factors for Toxoplasma infection (e.g.frequency of consumption of undercooked meat, unwashed raw vegetables and/or unwashed raw fruit, contact with soil, and main sources of drinking water) were collected. Each subject was then checked for anti-Toxoplasma gondii IgG and IgM in commercial ELISA. Of the 554 expectant women investigated, 51.4% were found seropositive for anti-Toxoplasma IgG (indicating chronic infection) and 8.8% for anti-Toxoplasma IgM (indicating acute infection), with 6.1% of the women seropositive for Toxoplasma -specific IgM but seronegative for Toxoplasma-specific IgG. Acute infection was most common among the women who were relatively young, lived in rural areas and had relatively low incomes. The results of a multivariate logistic regression indicated that the significant positive predictors for chronic Toxoplasma infection were increasing age, rural residence, low family income, frequent consumption of undercooked meat, and previous obstetric problems (and/or multiparity). Although of questionable accuracy, the results of the present study revealed a relatively high seroprevalence of (possibly primary) acute Toxoplasma infection in the pregnant women, with the potential for transmission of the parasite to the foetuses.

Use of Dense Granule Antigen GRA6 in an Immunoglobulin G Avidity Test To Exclude AcuteToxoplasma gondiiInfection during Pregnancy

The usefulness of a specific immunoglobulin G (IgG) avidity enzyme-linked immunosorbent assay (ELISA) based on recombinant GRA6 antigen for distinguishing between acute and chronic Toxoplasma infection was investigated. Two sets of serum samples obtained from pregnant women with acute, chronic, or no Toxoplasma infection collected in France and Iran were used. Among the French subjects, 19 of 20 (95%) women who experienced seroconversion during the past 4 months before sampling displayed low-avidity IgG antibodies against GRA6, while all 17 (100%) women with chronic infection had high-avidity antibodies. When the Euroimmun IgG avidity ELISA was used, 15 of 19 (78.9%) recently infected women had low-avidity antibodies, and 20 of 22 (90.9%) women with chronic infection displayed high-avidity antibodies. The results suggested better performance of the GRA6 avidity ELISA than the Euroimmun avidity ELISA for exclusion of a recent infection occurring less than 4 months previously. Similarly, all 35 Iranian women with acute Toxoplasma infection had low-avidity antibodies against GRA6, whereas all 34 women with chronic infection displayed IgG antibodies of high avidity, indicating the value of GRA6 avidity testing for ruling out a recent infection. Avidity tests based on lysed whole-cell Toxoplasma gondii antigen are currently used to exclude recently acquired infections; however, the use of recombinant antigen(s) might improve the diagnostic performance of avidity tests and facilitate the development of more standardized assays.

Screening for toxoplasmosis during pregnancy: One-year experience in an Italian reference laboratory

AIMS: To describe the experience of the Toxoplasmosis Laboratory of Infectious Disease Department University of Pavia, IRCCS Foundation, San Matteo Polyclinic Pavia, a reference laboratory for diagnosis of toxoplasmosis, in the investigation of pregnant women with suspected acute toxoplasmosis. METHODS: All sera were tested with LIAISON® Toxo IgM and IgG II, Toxo IgG Avidity II kits (DiaSorin, Saluggia, Italy), VIDAS Toxo IgG II and Toxo IgG Avidity (bioMérieux, Marcy l’Etoile, France ), IgM ISAGA (bioMérieux, Marcy l’Etoile, France) and ETI-TOXOK-A reverse PLUS (DiaSorin, Saluggia, Italy). When required (IgG negative/IgM positive women), IgG/IgM Western Blot II (LDBio, Lyon, France) was also performed. Prenatal diagnosis on amniotic fluid was done by nested PCR. All newborns were followed up to one year of age in order to exclude or confirm the diagnosis of congenital toxoplasmosis. All pregnant women with acute or undetermined stages of infection were treated. RESULTS: In the course of 2007, 236 women with suspected acute (IgM-positive) Toxoplasma infection were followed up. In the reference laboratory, 91 women had test results indicating acute toxoplasmosis, and 10 had undetermined status of infection. These 101 patients represented 42.8% of the 236 women referred. Acute toxoplasmosis could be excluded in the remaining 135 patients, of whom 53 were non-immune. Three infected newborns were observed, all from mothers tested for the first time during the third trimester of pregnancy. CONCLUSIONS: The role of a reference laboratory in suspected toxoplasmosis acquired during pregnancy is crucial to date the infection and discriminate between seroconversion and false positive anti-Toxoplasma IgM antibodies. This avoids unnecessary anxiety in immune women, provides correct counseling about primary prevention and periodic testing for seronegative ones, and allows early treatment and follow-up of pregnant women with acute infection and their newborns.

Detection of Acute Toxoplasma gondii infection in early pregnancy by IgG-avidity and PCR analysis

Acute Toxoplasma gondii infection in early pregnancy carries the risk of transmitting the infection to the fetus with serious sequelae. However, serological testing for IgG/IgM anti-Toxoplasma antibodies may fail to differentiate between a recent and past infection. Two hundred and twenty-four Kuwaiti women in their first trimester were screened for IgG/IgM antibodies by the Vitek Immuno Diagnostic Assay System (VIDAS) and VIDAS IgG-avidity tests. On serological screening, 119 (53.1 %) women were positive for IgG antibodies and 31 (13.8 %) for IgM antibodies. Nine of the IgM-positive and 7 IgM-negative women had low-avidity antibodies. However, the IgG-avidity test detected low-avidity antibodies only in 9 (29 %) of the 31 IgM-positive women, suggesting a recent infection; 19 (61.3 %) women had high-avidity antibodies, indicating that the infection was acquired in the distant past. Based on IgM serology alone, at least 31 IgM-positive women may have been wrongly labelled as having acute Toxoplasma infection thus warranting appropriate therapeutic intervention. All the 19 IgM-positive women with high-avidity antibodies were confirmed negative for Toxoplasma DNA on PCR analysis. Compared with PCR analysis, the VIDAS avidity test was a helpful tool for the diagnosis of recent Toxoplasma infection in IgM-negative women with low-avidity antibodies and IgM-positive women with high-avidity antibodies; the specificity was >85 -100 %. It is concluded that the VIDAS avidity test when used in combination with VIDAS IgG/IgM tests is a valuable assay for the exclusion of ongoing or recently acquired T. gondii infection in pregnant women in their first trimester and that it decreases significantly the necessity for follow-up testing and unnecessary therapeutic intervention.

Post-treatment assessment of acute Toxoplasma infection during pregnancy

SummarySerological immune profile in cases of Toxoplasma infection is heterogeneous, and responses may be delayed or fail to be represented: this makes it an unreliable method for diagnosis and/or treatment follow-up. Therefore, the present study relied on a sensitive and specific molecular procedure (nested polymerase chain reaction, PCR), using the whole blood sample to establish the diagnosis of acute maternal toxoplasmosis in 27 pregnant women. All of them received the recommended dose of Spiramycin. Only 19 returned for follow-up visits and completed their pregnancies to full term. The achievement of the treatment regimen was evaluated according to the results of PCR amplification of T. gondii DNA at the end of the treatment course. Patients who continued to have positive PCR results were given another treatment course. After treatment with a single course of Spiramycin, 11(57.9%) patients retained T. gondii DNA in their peripheral blood and in eight (42.1%) patients, T. gondii DNA was absent by PCR: four (21.01%) patients received up to three courses of treatment.

The dense granule protein GRA2, a new marker for the serodiagnosis of acute Toxoplasma infection: comparison of sera collected in both France and Iran from pregnant women

GRA2 is a highly immunogenic protein secreted from the dense granules of Toxoplasma gondii. Recent success in purifying full-length, soluble GRA2 from bacteria as a thioredoxin (TRX)-(Hisx6) fusion protein led to investigate the antigenicity of the recombinant protein against human sera. On immunoblots, TRX-(Hisx6)-GRA2 was recognized by sera collected in Iran from T. gondii-infected pregnant women. An IgG enzyme-linked immunosorbent assay was developed to evaluate the reactivity of sera, collected from pregnant women both in France and Iran, to the TRX-(Hisx6)-GRA2 fusion protein. Specificity of the test was 96.4%. Sensitivity of the GRA2 enzyme-linked immunosorbent assay ranged from 95.8% (sera collected in France) to 100% (sera collected in Iran) for sera of acute infection and from 65.7% (sera collected in France) to 71.4% (sera collected in Iran) for sera of chronic infection. The recombinant GRA2 could thus advantageously complement previously described T. gondii antigens for the serodiagnosis of acute Toxoplasma infection.

Is there any relationship between toxoplasma infection and reactive arthritis?

The diagnosis of reactive arthritis is a challenging clinical problem in daily practice. Although there are many triggering infectious agents for reactive arthritis, Toxoplasmosis, a worldwide parasitic infection has not been reported. We investigated the serologic evidence of Toxoplasma gondii ( T. gondii ) infection in patients with newly diagnosed reactive arthritis after six weeks of the onset of the first symptom but no demonstrable triggering agent for reactive arthritis. Clinical controlled study. We screened serologically the serum toxoplasma IgM and IgG antibody (Ab) titers which revealed toxoplasma infection in 50 patients with reactive arthritis (40 female, 10 men) and no demonstrable triggering agent and control subjects (32 female, 8 male). SPSS 10.0 software package program was used. The mean age of the patients and controls was similar (41.3+/- 12.0 vs. 39.6+/-11.8 years) respectively. The prevalence of IgG Ab titers of T. gondii in patients and controls were found to be 52% and 47.5%, respectively. Mean serum Toxoplasma IgG Ab levels were found to be 16.5+/-14.5 IU/ml, and 16.9+/-13.8 IU/ml in patients and control subjects respectively ( P> 0.05). We did not find any Toxoplasma IgM Ab titer demonstrating the acute or sub-acute infection in the serum of patients or controls. Although past Toxoplasma infection was prevalent in both groups, we did not find any subject with acute Toxoplasma infection in patients with newly diagnosed reactive arthritis and healthy controls. Despite the fact that our study group was small, we suggest that T. gondii does not seem to be a triggering agent for reactive arthritis and past infection may be a coincidental finding.

Usefulness of Toxoplasma gondii recombinant antigens (GRA1, GRA7 and SAG1) in an immunoglobulin G avidity test for the serodiagnosis of toxoplasmosis

The precise diagnosis of an acute and recent Toxoplasma infection in pregnant women and the newborn child is important before treatment. This study describes a new Toxoplasma gondii IgG avidity test based on a combination of recombinant GRA1, GRA7 and SAG1 antigens and shows that this test is useful for diagnostic purposes and may replace the lysed, whole-cell antigens. Although more sera need to be tested, the results obtained here suggest that the IgG avidity test performed with rec-antigens correlated more with the stage of a T. gondii infection than the IgG avidity results obtained with the lysed, whole-cell antigen test, the VIDAS Toxo IgG avidity (bioMérieux).

Seroprevalence of Toxoplasma gondii infection among pre-schoolchildren aged 1–5 years in the Democratic Republic of Sao Tome and Principe, Western Africa

The prevalence status of Toxoplasma gondii infection in children of the Democratic Republic of Sao Tome and Principe (DRSTP), Western Africa, is unknown to date. A serologic survey of T. gondii infection among pre-schoolchildren aged <5 years in the DRSTP was assessed by the latex agglutination (LA) test from November 2003 to March 2004. The overall seroprevalence of T. gondii infection was not low, reaching 21.49% (26/121). No significant gender difference in seroprevalence was found between boys (19.30%; 11/57) and girls (23.44%; 15/64) (chi2 = 0.31, P = 0.58). The older age group of 4-5 years had significantly higher seroprevalence (36.67%; 11/30) than the younger age group of <2 years (10.34%; 3/29) (chi2 = 5.64, P = 0.02). It was noteworthy that the majority of seropositive boys (90.91%; 10/11) or older children aged > or = 2 years (82.61%; 19/23) had high LA titres of > or = 1:1024, indirectly indicating acute Toxoplasma infection. This study is the first report indicating that T. gondii infection is not low in pre-schoolchildren aged <5 years in the DRSTP. Whether the DRSTP pre-schoolchildren acquire T. gondii infection through constant exposure to the parasite from their daily activities owing to poor environmental hygiene should be further evaluated.

Toxoplasmosis

Toxoplasma gondii is a worldwide zoonotic infection. The sexual cycle occurs only in the cat family; only the cat's faeces are infectious, but cysts in animals and birds can cause infection when these are consumed. Acquired acute Toxoplasma infection can be asymptomatic or have nonspecific, flu-like symptoms. Lymphadenopathy is the most recognized presentation and may last more than 6 months. Retinochoroiditis is usually a result of reactivated congenital infection. Increasingly recognized is chronic infection producing chronic fatigue syndrome. Reactivated infections, particularly in the immunocompromised, are a major problem and prophylaxis may be required. Toxoplasma status should also be determined before transplantation. Laboratory diagnosis depends on the presence of specific IgM or IgA, and by increases in specific IgG. Diagnosis may require Western blotting or polymerase chain reaction analysis. First-line treatment is pyrimethamine, sulfadiazine and folinic acid. Other drugs (clindamycin, clarithromycin, azithromycin or atovaquone) can be helpful.