Evaluation of the Eiken latex agglutination test for anti-Toxoplasma antibodies and seroprevalence of Toxoplasma infection among factory workers in Addis Ababa, Ethiopia

Potential risk factors associated with seropositivity for Toxoplasma gondii among pregnant women and HIV infected individuals in Ethiopia: A systematic review and meta-analysis

BACKGROUND

Toxoplasma gondii is an obligate intracellular and neurotropic apicomplexan protozoan parasite infecting almost all warm-blooded vertebrates including humans. To date in Ethiopia, no systematic study has been investigated on the overall effects of potential risk factors associated with seropositivity for Toxoplasma gondii among pregnant women and HIV infected individuals. We intended to determine the potential risk factors (PRFs) associated with seropositivity for Toxoplasma gondii from published data among pregnant women and HIV infected individuals of Ethiopia.

METHODOLOGY

An systematic review of the previous reports was made. We searched PubMed, Science Direct, African Journals Online, and Google Scholar for studies with no restriction on the year of publication. All references were screened independently in duplicate and were included if they presented data on at least two risk factors. Meta-analysis using the random or fixed-effects model was made to calculate the overall effects for each exposure.

RESULTS

Of the 216 records identified, twenty-four reports met our eligibility criteria, with a total of 6003 individuals (4356 pregnant women and 1647 HIV infected individuals). The pooled prevalences of anti-Toxoplasma gondii antibodies were found at 72.5% (95% CI: 58.7% - 83.1%) in pregnant women and 85.7% (95% CI: 76.3% - 91.8%) in HIV infected individuals. A significant overall effect of anti-Toxoplasma gondii seropositivity among pregnant women (p < 0.05) was witnessed with age, abortion history, contact with cats, cat ownership, having knowledge about toxoplasmosis, being a housewife and having unsafe water source. Age, cat ownership, and raw meat consumption were also shown a significant effect (p < 0.05) to anti-Toxoplasma gondii seropositivity among HIV infected individuals.

CONCLUSIONS

This review showed gaps and drawbacks in the earlier studies that are useful to keep in mind to design accurate investigations in the future. The pooled prevalence of anti-Toxoplasma gondii antibodies was found to be higher among pregnant women and HIV infected individuals. This suggests that thousands of immunocompromised individuals (pregnant women and HIV infected patients) are at risk of toxoplasmosis due to the sociocultural and living standards of the communities of Ethiopia. Appropriate preventive measures are needed to reduce the exposure to Toxoplasma gondii infection. Further studies to investigate important risk factors are recommended to support the development of more cost-effective preventive strategies.

A Review on the Present Advances on Studies of Toxoplasmosis in Eastern Africa

Toxoplasmosis is a zoonotic infection caused by the protozoan parasite, Toxoplasma gondii. It was discovered over 100 years ago and is credited as the most successful parasitic organism worldwide, able to infect and multiply in all warm blooded animals including an estimated 2.3 billion people. Toxoplasmosis is asymptomatic in immunocompetent individuals. Infection in the developing fetus and immunocompromised individuals can cause severe clinical disease. Toxoplasmosis is also a major cause of reproductive failure in livestock. The economic impact of toxoplasmosis is believed to be substantial. Factors associated with toxoplasmosis infection have been defined. Eastern Africa region is a high-risk area mainly due to the close association of humans and livestock as well as sociocultural practices, poor environmental hygiene, and poverty. The present paper provides a narrative review of published data on toxoplasmosis in Eastern Africa.

Seroprevalence and risk factors of Toxoplasma gondii infection in humans in East Hararghe Zone, Ethiopia

A cross-sectional study was conducted from April 2013 to September 2013 to determine the seroprevalence and possible risk factors for human Toxplasma gondii infection in East Hararghe Zone, Ethiopia. Serum samples were analysed using direct agglutination test, and immunosorbent agglutination assay for detecting IgG (n = 354) and IgM (n = 167) T. gondii antibodies. The T. gondii IgG and IgM seroprevalences were 65·8% [95% confidence interval (CI) 60·62–70·75] and 8·98% (95% CI 5·11–14·38), respectively. Gender difference in IgG seroprevalence was not significant (P > 0·05), but 69·5% of adults exhibited an IgG seroresponse to T. gondii. Pregnant women showed 76·4% and 9·3% seropositivity to IgG and IgM antibodies, respectively. Multivariable logistic regression analysis identified the risk factors significantly associated with T. gondii seropositivity were district [odds ratio (OR) 2·24, 95% CI 1·25–4·01, P = 0·007], pipe water source (OR 6·70, 95% CI 2·70–16·64, P < 0·001), age, with adults (OR 4·32, 95% CI 1·91–9·75, P < 0·001), and keeping cats in the home (OR 2·01, 95% CI 1·11–3·65, P = 0·021). The high seroprevalence of toxoplasmosis in the human population in the study area and the corresponding level of IgM seropositivity may be indicative of reactivation or recent infection and further studies on the status of congenital toxoplasmosis in the study area merit consideration.

A meta-analysis of the prevalence of Toxoplasma gondii in animals and humans in Ethiopia

BACKGROUND

Toxoplasmosis is a worldwide zoonosis. The objectives of this study were to estimate the prevalence and assess the potential risk factors of Toxoplasma gondii infections in animals and humans in Ethiopia by using meta-analytical methods.

METHODS

Published studies on T. gondii in animals and humans in Ethiopia were searched in Medline, Google Scholar and the lists of references of articles. Eligible studies were selected by using inclusion and exclusion criteria. The risks of within and across study biases, and the variations in prevalence estimates attributable to heterogeneities were assessed. Pooled prevalence was estimated by the DerSimonian and Laird random effects model.

RESULTS

Thirty two studies were eligible and data from 5689 animals and 5718 humans were used for quantitative syntheses. The pooled IgG seroprevalence in cats, small ruminants and humans were estimated at 87.72% (95% CI = 78.63, 93.28), 34.59% (95% CI = 21.08, 51.12) and 74.73% (95% CI = 61.85, 84.36), respectively. The odds of infections were higher in pregnant than in non pregnant women (OR = 3.96), in individuals that had contact with cats than those with no contact (OR = 2.53), and in urban than in rural inhabitants (OR = 2.06).

CONCLUSIONS

Toxoplasmosis is highly prevalent and could be a cause of considerable reproductive wastage in small ruminants and multiple diseases in humans in Ethiopia. Public education on preventive measures could help reduce the transmission of the parasite to humans.

Seroepidemiology of Toxoplasma gondii infection in women of child-bearing age in central Ethiopia

Background

Toxoplasma gondii infections during pregnancy can result in abortion or congenital defects. Prevalence and risk factors of toxoplasmosis in women of child-bearing age in Ethiopia are unknown. The current study was conducted with the objectives of estimating the seroprevalence and potential risk factors in acquiring T. gondii infection by women of child-bearing age in Central Ethiopia.

Methods

A cross-sectional study was conducted from March 2011 to September 2011. Sera of 425 women were analyzed by indirect enzyme linked immunosorbent assay (ELISA). A questionnaire survey was administered for all study participants to gather information on risk factors.

Results

The study revealed that anti- T. gondii IgG antibodies were detected in 81.4% of the samples of which 78.4% were positive for only IgG and 3.06% positive for both IgG and IgM antibodies. Seroprevalence of IgM antibodies to T. gondii (4.0%, 95% CI: 2.14, 5.86) was suggestive of recent infections. Of the 213 pregnant women 9 (4.2 %) were IgM reactive. Out of 17 potential risk factors investigated, univariate logistic regression showed significant association of T. gondii infection with study area, age, pregnancy status, raw vegetable consumption, source of water, presence of cats at home, contact with cats, HIV status and precaution during cats’ feces cleaning (P ≤ 0.05). The final logistic regression model revealed that: the probability of acquiring T. gondii infection by women of Debre-Zeit was 4.46 times (95% CI of adjusted odds ratio [aOR]: 1.67, 11.89; P =0.003) higher compared to women of Ambo, pregnant women were twice (95% CI aOR: 1.13, 3.59; P = 0.018) more likely to be seropositive than non-pregnant women and women who consume raw vegetable were at increased risk of infection (aOR = 2.21, 95% CI: 1.03, 4.78; P = 0.043) than women who didn’t consume.

Conclusion

The seroprevalence of T. gondii infection in women of child-bearing age in Central Ethiopia is high. Study area, pregnancy and raw vegetable consumption are risk factors to acquire T. gondii infection. Educational program, antenatal screening of pregnant women and further epidemiological studies to uncover the economic and health impact of toxoplasmosis are suggested.

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.

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

Background

The 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.

Methods

A 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).

Results

The 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).

Conclusions

Parents’ 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.

A review of toxoplasmosis in humans and animals in Ethiopia

Toxoplasmosis caused by the protozoan parasite, Toxoplasma gondii, is a worldwide zoonosis. In this paper published information on toxoplasmosis in humans and other animals in Ethiopia is reviewed. Limited data indicate that the prevalence of T. gondii in humans in Ethiopia is very high, up to 41% of children aged 1-5 years were reported to be seropositive. There is little information on seroprevalence data in pregnant women and no data on congenital toxoplasmosis in children. About 1 million adults in Ethiopia are considered to be infected with HIV with less than one-third likely receive highly active antiviral therapy. Based on a conservative T. gondii seroprevalence of 50%, thousands might die of concurrent opportunistic infections, including toxoplasmosis. However, exact figures are not available, and most serological surveys are not current. Serological surveys indicate up to 79% of goats and sheep have T. gondii antibodies. However, there is no information on losses due to toxoplasmosis in livestock or the presence of viable T. gondii in any host in Ethiopia.

Toxoplasmosis in rodents: ecological survey and first evidences in Thailand

Domestic and wild rodents known as the most abundant and diversified order of mammals have a key role in the ecological food chain and also in the transmission of parasites and pathogens to other animals. While foraging on the ground, they can get infected by Toxoplasma gondii, a protozoan parasite, which is the causative agent of toxoplasmosis. Therefore, they serve as intermediate hosts of T. gondii and can transmit it to their predators. To assess their role in the maintenance of T. gondii lifecycle in Thailand, we sampled rodents in a range of biotopes representative of the high biodiversity and conducted a serological survey with latex agglutination test to detect anti-T. gondii antibodies. Overall, 21 of 461 (4.6%) rodents had diagnostically significant antibody titers (cutoff, 1:64). Every species with at least 37 individuals captured tested positive, confirming the wide range of potential mammalian hosts of toxoplasmosis. None of the ecological traits (sex, maturity, morphology, season, or habitat) was found significant to predict the susceptibility to T. gondii both univariately and in a multivariate analysis. However, high prevalences were reported in either forested or anthropized areas. This survey constitutes the first confirmed serological investigation of T. gondii in rodents in Thailand. The rarity of both domestic and wild felids in Thailand emphasizes the importance of rodents in maintaining T. gondii, and questions the involvement of other carnivores in the life cycle.

Trimethoprim as adjuvant treatment in schizophrenia: a double-blind, randomized, placebo-controlled clinical trial

Various infectious agents, such as Toxoplasma gondii, have been hypothesized to be potentially relevant etiological factors in the onset of some cases of schizophrenia. We conducted a randomized, double-blind, placebo-controlled treatment trial in an attempt to explore the hypothesis that the symptoms of schizophrenia may be related to infection of the central nervous system with toxoplasma gondii. Systematically selected patients with ongoing and at least moderately severe schizophrenia from Butajira, in rural Ethiopia, were randomly allocated to trimethoprim or placebo, which were added on to participants' regular antipsychotic treatments. Trial treatments were given for 6 months. The Positive and Negative Syndrome Scale (PANSS) was used to assess outcome. Ninety-one patients were included in the study, with 80 cases (87.9%) positive for T. gondii immunoglobulin G antibody. Seventy-nine subjects (87.0%) completed the trial. The mean age of subjects was 35.3 (SD = 8.0) years, with a mean duration of illness of 13.2 (SD = 6.7) years. Both treatment groups showed significant reduction in the overall PANSS score with no significant between-group difference. In this sample of patients with chronic schizophrenia, trimethoprim used as adjuvant treatment is not superior to placebo. However, it is not possible to draw firm conclusion regarding the etiological role of toxoplasmosis on schizophrenia based on this study because the timing and the postulated mechanisms through which toxoplasmosis produces schizophrenia are variable.

Sero-prevalence of latent Toxoplasma gondii infection among HIV-infected and HIV-uninfected people in Addis Ababa, Ethiopia: A comparative cross-sectional study

Background

Toxoplasmosis in immuno-compromised hosts manifests primarily as a life threatening condition, toxoplasmic encephalitis. However, there is scarce information about the magnitude of Toxoplasma gondii infection among HIV-infected people in Ethiopia. This study was, therefore, conducted to determine the sero-prevalence of T. gondii infection among HIV-infected and HIV-uninfected subjects.

Findings

Sera were collected from people with and without HIV infection for the purpose of studying hepatitis B virus (HBV) at St. Paul Hospital, Addis Ababa, Ethiopia from 24 January 2007 to 15 February 2007. Among these sera, the first 330 consecutive sera, 165 from each HIV sero-group, were selected and tested for anti-T. gondii IgG antibodies using Enzyme Linked Immunosorbent Assay. The seroprevalence of Toxoplasma infection was assessed against socio-demographic characteristics, HIV and HBV serostatus and HBV-related risk factors. The overall sero-prevalence of latent T. gondii infection among the study subjects was 90.0%. Toxoplasma infection was observed with respective prevalence of 93.3% and 86.7% among HIV-infected and HIV-uninfected people. Though Toxoplasma infection seems to be influenced by age, gender and HIV serostatus, only HBV serostatus was significantly associated (OR 2.71, CI 1.12 to 6.57) in multivariate logistic regression analysis.

Conclusion

The seroprevalence of latent T. gondii infection is high and similar by HIV status. Educating people to prevent acquisition of new Toxoplasma infection and minimizing the risk of disease manifestations among HIV-Toxoplasma co-infected individuals is important.

Neurological evaluation of untreated human immunodeficiency virus infected adults in Ethiopia

Human immunodeficiency virus (HIV) has been implicated in neurological complications in developed countries. Developing countries have different viral clades and potentially different genetic and social risks for these complications. Baseline neurological performance measures associated with HIV infection have rarely been available from developing countries. The authors carried our a cross-sectional neurological evaluation of a cohort of community-dwelling treatment-naïve HIV-infected patients and similar control subjects from the same communities in Ethiopia. Blinded evaluation using standardized structured questionnaires and a neurological examination was performed by neurologists and treating physicians trained by an HIV neurology specialist. Quantitative performance measures for cognitive and motor function were employed. Data were analyzed with descriptive statistical methods, standard contingency table methods, and nonparametric methods. HIV-positive and control groups were similar by age, gender, and job site. Participants included 73 HIV-positive and 87 HIV-negative controls. Fingertapping speed in the dominant hand was more poorly performed in HIV positives than negatives (P = .01) and was significantly associated with HIV viral load levels (P = .03). Other quantitative neuropsychiatric tests including timed gait, grooved pegboard, task learning, and animal naming did not show significant differences between the two groups. The overall prevalence of central nervous system (CNS) and/or peripheral nervous system (PNS) disease did not significantly differ in the two populations. HIV patients had slowed fingertapping speed correlating with viral load. Other measures of CNS and/or peripheral nervous performance did not differ from controls. The unanticipated minor evidence of HIV-associated neurocognitive and peripheral nerve deficits in this untreated HIV-positive population invite further investigation.

Seroprevalence of Toxoplasma gondii infection among inhabitants in the Democratic Republic of Sao Tome and Principe

The level of Toxoplasma gondii infection among the general population of the Democratic Republic of Sao Tome and Principe is unclear. The T. gondii infection status of inhabitants who visited National Central Hospital on Sao Tome Island was assessed by a latex agglutination test. The overall seroprevalence was 74.5% (120/161). No significant gender difference in seroprevalence was found between males and females. The older age group (> or =45 years) had significantly higher seroprevalence (80.0%, 28/35) than the younger age group (<15 years) (20.0%, 3/15) (chi(2)=16.04, P<0.001).

Serological screening and toxoplasmosis exposure factors among pregnant women in the Democratic Republic of Sao Tome and Principe

The seroprevalence of Toxoplasma gondii infection among pregnant women in the Democratic Republic of Sao Tome and Principe (DRSTP) from November 2003 to March 2004 was determined by detection of serum anti-T. gondii antibodies. A short questionnaire interview for pregnant women was performed to investigate risk factors associated with T. gondii infection, including consumption of raw meat or unwashed vegetables, drinking unboiled water and keeping pets (cats and dogs). The overall seroprevalence of T. gondii infection was high (75.2%; 375/499). The older age group of > or =35 years had a significantly higher seroprevalence (85.7%; 54/63) than that of the younger age group of 15-25 years (70.4%; 178/253) (odds ratio 2.5, 95% CI 1.2-5.4; P=0.01). No significant difference in the seroprevalence of T. gondii infection was found between the pregnant women with and without exposure to the risk factors studied. However, among pregnant women with high antibody titers of > or =1:1024, it seemed likely that continual contact with pets and consumption of oocyst-contaminated water or raw unwashed vegetables rather than tissue cysts in meat was the primary route of infection. The incidence of congenital toxoplasmosis in unborn babies should be intensively monitored in the DRSTP.

Seropositivity rates for Bartonella henselae, Toxocara canis and Toxoplasma gondii in New Zealand blood donors

BACKGROUND

Bartonella henselae, Toxocara canis and Toxoplasma gondii organisms can all cause vision-threatening posterior segment disease. Diagnosis relies heavily on clinical findings, but detection of antibodies in the patient's serum may be helpful in some cases. The significance of a positive serology result depends on the seroprevalence in the general population. Seroprevalence rates for these organisms vary widely around the world and this study aimed to determine the rates for a New Zealand population.

METHODS

One hundred and forty healthy blood donors from the Waikato region in the North Island of New Zealand had their serum tested using an indirect latex agglutination test for detection of T. gondii antibodies, an indirect immunofluorescent assay for B. henselae antibodies and an enzyme-linked immunosorbent assay test for T. canis antibodies.

RESULTS

Seropositivity rates for T. canis, T. gondii and B. henselae in this New Zealand population were 0.7 +/- 1.65%, 42.9 +/- 8.12% and 5 +/- 3.61%, respectively.

CONCLUSION

Seropositivity rates for T. gondii and B. henselae in New Zealand are similar to rates reported in some other countries; however, T. canis seroprevalence may be lower than reported elsewhere in the world.

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.

Serological evidence for remarkably variable prevalence rates of Toxoplasma gondii in children of major residential areas in United Arab Emirates

The major objective of this study was to determine the seroprevalence rate of Toxoplasma gondii in children citizens of United Arab Emirates (UAE) main residential areas. Questionnaire information, clinical data and blood samples were obtained from 1006 primary school children residence of seven out of nine districts of UAE. ELISA was used for detection of antibodies against the immunodominant surface antigen (SAG1) of T. gondii. The sensitivity and specificity of the employed ELISA were 98.4 and 99.1%, respectively using 'Eiken' latex agglutination test as a reference test. The seroprevalence rates were remarkably variable in different residential areas and ranged between 3.5% for Dubai and 34.6% for Sharjah, with an overall prevalence of 12.5% for the seven districts. Rear of ruminants at home and consumption of raw milk associated significantly (P<0.05) with exposure to T. gondii. UAE children exposed to T. gondii infection had a significantly higher hepatomegaly rate (P<0.05) and complained more of various symptoms at the time of sampling (P<0.01) compared to unexposed children. This study urges for more population studies to further elucidate the prevalence rates of toxoplasmosis in UAE in relation to age, gender, place of residence and risk factors.

Evaluation of the World Health Organization staging system for HIV infection and disease in Ethiopia: association between clinical stages and laboratory markers

OBJECTIVE

To study the association between the clinical axis of the World Health Organization (WHO) staging system of HIV infection and disease and laboratory markers in HIV-infected Ethiopians.

DESIGN

Cross-sectional study.

METHODS

Clinical manifestations and stage of HIV-positive individuals participating in a cohort study of HIV infection progression, and of HIV-positive patients hospitalized with suspicion of AIDS, were compared to CD4+ T-cell count and viral load.

RESULTS

Of the 86 HIV-positive participants of the cohort study, 53 (62%), 16 (19%), 16 (19%), and one (1.2%) were in stage 1, 2, 3 and 4, respectively. Minor weight loss (n = 15) and pulmonary tuberculosis (n = 9) were the most commonly diagnosed conditions among the 38 (44%) symptomatic HIV-positive individuals. Although 23 (27%) HIV-positive participants had CD4+ T-cell counts less than 200 x 10(6)/l, only one was in clinical stage 4. Among 79 hospitalized HIV-positive patients, 15 (19%) and 64 (81%) were in stage 3 and 4, respectively. The majority (83.5%) had CD4+ T-cell counts < 200 x 10(6)/l. Individuals at stage 3 had lower CD4+ T-cell counts and higher viral loads when seen in hospital as compared to cohort participants (P = 0.06 and 0.008, respectively). When grouping the two study populations, the median CD4+ T-cell count decreased (337, 262, 225, 126, and 78 x 10(6)/l, P< 0.01), and the median viral load increased (4.08, 3.89, 4.47, 5.65, and 5.65 log10 copies/ml, P < 0.01), with increasing clinical stage of HIV infection (1, 2, 3 cohort, 3 hospital, and 4, respectively). Median CD4+ T-cell counts were remarkably low in HIV-negative participants (749 x 10(6)/l), and in HIV-positive participants at stage 1 and 2 (337 and 262 x 10(6)/l, respectively).

CONCLUSIONS

There was a good correlation between WHO clinical stages and biological markers. CD4+ T-cell counts were low in Ethiopians, particularly during early stages of HIV-1 infection, and preliminary reference values at different stages of HIV-1 infection were determined. In HIV-infected Ethiopians, lymphocyte counts less than 1,000 x 10(6)/l in non-hospitalized individuals, and less than 2,000 x 10(6)/l in hospitalized patients, had high positive predictive value, but low sensitivity, in identifying subjects with low CD4+ T-cell counts (< 200 x 10(6)/l) who would benefit from chemoprophylaxis of opportunistic infections. The on-going longitudinal study will be useful to confirm the prognostic value of the WHO staging system.