Seroprevalence of and risk factors for Toxoplasma gondii antibodies among asymptomatic blood donors in Egypt

First report of Toxoplasma gondii in camels (Camelus dromedarius) in Ethiopia: bioassay and seroepidemiological investigation

Background

Toxoplasmosis is a major public health concern in many countries of the world. A cross-sectional and follow up experimental study designs were used for seroepidemiological and bioassay studies, respectively from November 2012 to April 2013. The objectives were to estimate the seroprevalence of T. gondii infection, to assess risk factors and to isolate the parasite from camels in the Fentale district, Ethiopia. A direct agglutination test (DAT) and indirect enzyme linked immunosorbent assay (ELISA) kits were used to test camel sera. Hearts and tongues (each 25 g) from 31 seropositive camels were bioassayed in mice. Associations between seroprevalence and potential risk factors (collected using a questionnaire survey) were analyzed using logistic regression.

Results

An overall T. gondii prevalence of 49.62% (220/455) by DAT and 40.49% (179/451) by indirect ELISA test were detected. Herd level seroprevalence of 96.77% (30/31) (95% CI: 83.30– 99.92) by DAT was recorded and it was significantly higher in areas where wild felids are present (P = 0.038). Multivariable logistic regression showed that the likelihood of acquiring T. gondii infection was significantly higher in camels in the Ilala pastoral association [PA] (82.26%) (Adjusted Odds ratio [aOR] = 10.8; P < 0.001) than camels in the Galcha PA (31.43%), in camels of ≥ 8 years old (56.52%; aOR = 1.88; P = 0,033) than camels of ≤ 4 years old (34.26%) and in areas where domestic cats are present (aOR = 4.16; P = 0.006). All camel owners were uneducated, handle aborted fetus with bare hands, and drink raw camel milk. DAT and ELISA tests had moderate agreement (Kappa = 0.41). Viable T. gondii were isolated from 16.13% (5/31) of DAT positive camels. One DAT positive but ELISA negative camel sample gave a cyst positive result.

Conclusions

T. gondii infection of camels in the study district is widespread. Age, presence of domestic cats and study PA are independent predictors of T. gondii seropositivity. Isolation of viable parasites from edible tissues of camels and the very poor knowledge of pastoralists about toxoplasmosis suggest the need for prevention of toxoplasmosis through bio-security measures, education and further investigation to unravel the impact of camel toxoplasmosis deserves consideration.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-014-0222-7) contains supplementary material, which is available to authorized users.

Review of parasitic zoonoses in egypt

This review presents a comprehensive picture of the zoonotic parasitic diseases in Egypt, with particular reference to their relative prevalence among humans, animal reservoirs of infection, and sources of human infection. A review of the available literature indicates that many parasitic zoonoses are endemic in Egypt. Intestinal infections of parasitic zoonoses are widespread and are the leading cause of diarrhea, particularly among children and residents of rural areas. Some parasitic zoonoses are confined to specific geographic areas in Egypt, such as cutaneous leishmaniasis and zoonotic babesiosis in the Sinai. Other areas have a past history of a certain parasitic zoonoses, such as visceral leishmaniasis in the El-Agamy area in Alexandria. As a result of the implementation of control programs, a marked decrease in the prevalence of other zoonoses, such as schistosomiasis and fascioliasis has been observed. Animal reservoirs of parasitic zoonoses have been identified in Egypt, especially in rodents, stray dogs and cats, as well as vectors, typically mosquitoes and ticks, which constitute potential risks for disease transmission. Prevention and control programs against sources and reservoirs of zoonoses should be planned by public health and veterinary officers based on reliable information from systematic surveillance.

Seroprevalence and risk factors for Toxoplasmosis in HIV infected and non-infected individuals in Bahir Dar, Northwest Ethiopia

Background

Toxoplasmosis, a zoonotic disease distributed worldwide, is an infection caused by the ubiquitous obligatory intracellular coccidian protozoan organism, Toxoplasma gondii. It is a major public health concern because the disease is serious in terms of mortality or physical and /or psychological sequellae in patients with HIV disease. The aim of the study was to assess the seroprevalence of Toxoplasma gondii IgG and IgM antibodies and associated risk factors in HIV infected and non-infected individuals attending Felege Hiwot referral hospital, Bahir Dar, Northwest Ethiopia.

Methods

A cross sectional study was conducted at Felege Hiwot referral hospital, Bahir Dar, Amhara National Regional State. Venous blood samples were collected from 103 HIV infected pre anti-retroviral therapy patients at Felege Hiwot referral hospital and 101 HIV negative apparently healthy voluntary blood donors at the blood bank. Serum samples were analyzed for anti-Toxoplasma gondii IgG and IgM antibodies using a commercially available ELISA kit. Socio-demographic and associated risk factors for Toxoplasmosis from each individual were also obtained and the data was analyzed using SPSS version 18.

Results

Of the examined HIV seropositive individuals, 87.4% (90/103) and 10.7% (11/103) were positive for anti-T. gondii IgG and IgM antibodies, respectively. Multivariate analysis using logistic regression showed that anti-T. gondii seropositivity was independently significantly associated with undercooked or raw meat consumption (adjusted OR=5.73, 95% CI=1.35-24.39; P=0.02) and having contact with cat (adjusted OR= 4.29, 95% CI=1.08-16.94; P=0.04) in HIV positive individuals. In HIV negative apparently healthy blood donors, prevalence of anti-T. gondii antibodies were 70.29% and 2.97% for IgG and IgM, respectively. Multivariate analysis showed that undercooked or raw meat consumption (adjusted OR=6.45, 95% CI=2.16-19.28; p=0.001) and sex (OR=6.79, 95% CI=2.14-21.60; p=0.001) were independently significantly associated with anti-T. gondii IgG seropositivity, with a significantly higher number of males affected than females.

Conclusion

The present findings showed a high sero-prevalence of anti-T. gondii antibodies in HIV infected pre-ART and HIV non-infected apparently healthy blood donors in Bahir Dar. Consumption of undercooked or raw meat might greatly contribute towards acquiring T. gondii infection in HIV infected pre-ART and HIV non-infected apparently healthy blood donors. It may be appropriate to include routine serological screening test for determination of anti-T. gondii antibodies in HIV infected pre-ART individuals and HIV negative apparently healthy blood donors. In addition, health education towards avoiding eating undercooked and raw meat, and avoiding contact with cats were recommended.

Seroepidemiology of Toxoplasma gondii Infection among healthy blood donors in Taiwan

Toxoplasma gondii is an opportunistic, zoonotic pathogen with a worldwide distribution. There are large variations in the seroprevalence of T. gondii infection in different regions of the world. Although toxoplasmosis became a notifiable communicable disease in Taiwan in 2007, little is known about its epidemiology among the general population. This cross-sectional study aimed to survey the seroprevalence of T. gondii infection and its risk factors among healthy blood donors in Taiwan. Through collaborating with the Taiwan Blood Services Foundation, a total of 1,783 healthy blood donors from all six-branch blood service centers participated in this study. The blood samples were tested for the presence of T. gondii antibodies and DNA using enzyme immunoassays and real-time PCR, respectively. Structured questionnaires were used to gather information on risk factors for T. gondii infection. Of the 1,783 participants, 166 (9.3%) tested positive for anti-Toxoplasma IgG, while 5 (0.28%) tested positive for anti-Toxoplasma IgM. The five IgM positive donors had high avidity antibodies suggestive of past infection. No active parasitemia was detected by real-time PCR assays. Multivariate logistic regression showed that undercooked pork meat consumption (adjusted odds ratio [OR] = 2.9; 95% confidence interval [CI]: 1.3–6.5), raw mussels consumption (adjusted OR = 5.3; 95% CI: 1.5–19.1), having a cat in the household (adjusted OR = 2.0; 95% CI: 1.2–3.2), a lower education level (adjusted OR = 1.6; 95% CI: 1.1–2.3), and donation place in eastern Taiwan (adjusted OR = 2.5; 95% CI: 1.6–3.9) were independent risk factors for Toxoplasma seropositivity. These findings provide information on the seroprevalence and epidemiology of T. gondii infection among healthy blood donors in Taiwan.

Detection of Toxoplasma gondii DNA by PCR in blood samples collected from pregnant Saudi women from the Aseer region, Saudi Arabia

BACKGROUND AND OBJECTIVES

Toxoplasmosis, caused by Toxoplasma gondii, is diagnosed mainly by serological methods that are hindered by insufficient sensitivity. When it fails, it becomes necessary to rely on either direct detection of the parasite or DNA detection by polymerase chain reaction (PCR). We aimed to establish molecular tools for toxoplasmosis research in the country by using PCR targeting the B1 gene and compare it with ELISA results.

DESIGN AND SETTING

Conducted at the College of Science, King Khalid University, Abha, Saudi Arabia between January 2009 and April 2010 on Saudi pregnant women attending three major hospitals in the Aseer region.

PATIENTS AND METHODS

Peripheral blood samples (n=137) were collected from patients. DNA was extracted and the B1 T gondii gene was amplified by PCR. The amplicons were visualized and sequenced, and the results were analyzed. For comparison, sera were tested for anti-T gondii IgG and IgM by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Of the 137 samples tested, the B1 gene could be amplified in 56 cases (41%) by PCR. DNA sequencing confirmed these results. IgM-ELISA assay detected 9 (6.5%) of these cases. The results of immunoglobulin G detection were positive in 53 (38.6%) of the patients.

CONCLUSION

The present study showed the need for PCR as a confirmatory assay in addition to serological assays to detect recent infection. We recommend national implementation of these molecular diagnostic tools.

Seroprevalence and risk factors for toxoplasmosis among antenatal women in London: a re-examination of risk in an ethnically diverse population

Background: Primary infection with Toxoplasma gondii in pregnancy can result in miscarriage, hydrocephalus, cerebral calcification and chorioretinitis in the newborn. The objective of our study was to evaluate seroprevalence of and analyse risk factors for toxoplasmosis in antenatal women from 2006 to 2008 in an ethnically diverse population of Central London to re-examine the need for a screening policy. Methods: We performed serum IgG estimations to T. gondii using a commercial kit, and analysed risk factors for acquisition using a questionnaire. Results: Seroprevalence for T. gondii was 17.32% in 2610 samples tested. In all, 67.7% were of UK origin (seroprevalence: 11.9%) and were significantly non-immune to T. gondii (OR: 0.38, 95% CI: 0.31–0.47; P < 0.0001). Risk factors for seroprevalence included African/Afro-Caribbean (OR: 2.67, 95% CI: 1.83–3.88; P < 0.001; seroprevalence: 31.5%), Middle eastern (OR: 3.12, 95% CI: 1.62–5.99; P ≤ 0.001; seroprevalence: 34.8%) and mixed (OR: 1.75, 95% CI: 1.16–2.63; P = 0.007; seroprevalence: 23.3%) ethnic groups; eating undercooked meat (OR: 1.64, 95% CI: 1.29–2.08; P ≤ 0.001; seroprevalence: 20.2%) and drinking unpasteurised milk (OR: 1.38, 95% CI: 1.01–1.88; P = 0.05; seroprevalence: 23.1%). There was no association with pet cats or eating unpasteurised cheeses and antibody responses. Conclusion: Low national prevalence of toxoplasma seroconversion and congenital disease would likely not justify screening in the UK. Individual risk assessment is recommended in ethnically diverse urban areas where populations with relatively high seroprevalence and parasite-associated risk factors exist together with an indigenous population with low prevalence. One universal screening policy based on the indigenous prevalence and risk factors may not be suitable for all.

Congenital toxoplasmosis: evaluation of molecular and serological methods for achieving economic and early diagnosis among Egyptian preterm infants

BACKGROUND

Early diagnosis of congenital toxoplasmosis (CT) is difficult when specific immunoglobulin M (IgM) antibodies are absent, or if persist for months, in the newborn infant's blood.

OBJECTIVES

To study the risk factors of neonatal toxoplasmosis and to compare different immunologic profiles (Toxoplasma-specific IgM, IgA antibodies and the avidity of IgG antibodies) with polymerase chain reaction (PCR) for reaching economic and early postnatal diagnosis.

MATERIALS AND METHODS

We prospectively studied 80 preterm neonates, recruited from neonatal intensive care units (NICUs) of Cairo University hospitals. Whose gestational age ≤ 34 weeks with (n = 60) or without (n = 20) CT risk. Serum samples for specific IgA, IgM antibodies and avidity of IgG toxoplasma antibodies were measured by ELISA then compared to PCR.

RESULTS

Of the 60 studied cases, 16 (26.7%) were positive for toxoplasmosis by PCR, of which 15 (25%) had low avidity of IgG antibodies (positive), 14 (23.3%) were positive for IgA and 10 (16.7%) were positive for IgM, with sensitivity for avidity of IgG, IgA and IgM: 93.2%, 87.5% and 62.5%, respectively.

CONCLUSION

Determination of avidity of IgG toxoplasma antibodies and/or serological detection of specific IgA for toxoplasmosis offer, simple tests for diagnosis of congenital toxoplasmosis with (better sensitivity) than IgM.