Female Genital Schistosomiasis Lesions Explored Using Circulating Anodic Antigen as an Indicator for Live Schistosoma Worms

Background

In areas where reinfection with schistosomiasis is rampant, it is not known if the lesions of Female Genital Schistosomaisis are a consequence of live worms, or caused by dead ova. Live schistosome worms regurgitate Circulating Anodic Antigen (CAA). We sought to explore the association between the different lesions of FGS (grainy sandy patches, homogenous yellow patches, rubbery papules and abnormal blood vessels) and the presence of live worms as indicated by S. haematobium-derived CAA in blood.

Materials and Methods

In this cross-sectional study, rural high schools were randomly selected from Ilembe, uThungulu and Ugu Districts on the East Coast of South Africa, KwaZulu-Natal Province. Serum samples for CAA analysis were collected from 246 female learners aged 16 - 23 years. Uncorrected chi-square and odds ratio with 95% confidence interval (CI) were used to evaluate the null hypothesis.

Results

CAA was positive in 82/246 (33%) of the participants. Sandy patches were found in 123 (50%) of the study population. Grainy sandy patches were significantly associated with CAA even after controlling for age (Adjusted Odds Ratio (AOR) 4.2, 95% CI 2.3 - 7.9, p < 0.001). Likewise, abnormal blood vessels were associated with CAA (AOR 3.0, 95% CI 1.5-4.5, p = 0.001) whereas homogenous yellow patches were not associated with CAA (p = 0.57). Rubbery papules were not found in this study population.

Conclusion

Grainy sandy patches and abnormal blood vessels are found more commonly in women who harbour live Schistosoma haematobium worms whilst homogenous yellow patches may indicate chronic tissue damage due to dead ova.

Mapping Schistosoma haematobium for Novel Interventions against Female Genital Schistosomiasis and Associated HIV Risk in KwaZulu-Natal, South Africa

Women with female genital schistosomiasis (FGS) have been found to have genital symptoms and a three-fold higher risk of HIV infection. Despite WHO recommendations, regular antischistosomal mass drug administration (MDA) has not yet been implemented in South Africa possibly because of the lack of updated epidemiological data. To provide data for future prevention efforts against FGS and HIV, this study explored Schistosoma haematobium prevalence in girls and young women and the effects of antischistosomal MDA, respectively. Urinary schistosomiasis and genital symptoms were investigated in 70 randomly selected secondary schools in three districts within KwaZulu-Natal and 18 primary schools. All study participants were treated for schistosomiasis, and schools with the highest urinary prevalence were followed up after 1 and 4 years of MDA. At baseline, urine analysis data showed that most schools were within the moderate-risk prevalence category where biennial antischistosomal MDA is recommended, as per WHO guidelines. Young women had high prevalence of genital symptoms (36%) after correcting for sexually transmitted infections. These symptoms may be caused by infection with schistosomes. However, FGS cannot be diagnosed by urine analysis alone. In KwaZulu-Natal rural schools, this study suggests that antischistosomal MDA with praziquantel could prevent genital symptoms in more than 200,000 young women. Furthermore, it is feasible that more than 5,000 HIV infections could be prevented in adolescent girls and young women by treatment and prevention of FGS.

Reproductive health problems in rural South African young women: risk behaviour and risk factors

BACKGROUND

South African young women continue to be vulnerable, with high prevalence of teenage pregnancy, HIV, sexually transmitted infections (STIs) and female genital schistosomiasis (FGS). This study seeks to examine the underlying factors that may be associated with these four adverse reproductive health outcomes.

METHODS

In a cross-sectional study of 1413 sexually active of young women, we explored these four adverse reproductive health outcomes by considering socio-demographic factors, socio-economic factors, sexual risk behaviour, substance abuse and knowledge about reproductive health by using a questionnaire. Consenting participants were asked about previous pregnancies and were tested for HIV, STIs and FGS. Multivariable regression analyses were used to explore the factors associated with these four reproductive health outcomes.

RESULTS

1. Early pregnancy: Among the young women, 44.4% had already been pregnant at least once. Associated factors were hormonal contraceptives, (adjusted odds ratio (AOR): 17.94, 95% confidence interval (CI): 12.73-25.29), and sexual debut < 16 years (AOR: 3.83, 95% CI: 2.68-5.47). Living with both parents (AOR 0.37, 95% CI: 0.25-0.57) and having a steady partner (AOR: 0.43, 95% CI: 0.24-0.76) were identified as protective factors against pregnancy. 2. HIV: HIV prevalence was 17.1%. The odds of having HIV were higher in intergenerational (AOR: 2.06, 95% CI: 1.05-4.06) and intragenerational relationships (AOR: 1.51 95% CI: 1.06-2.15), compared to age-homogenous relationships. Other associated factors were: condom use (AOR: 1.60, 95% CI: 1.16-2.20), number of times treated for an STI (AOR: 1.32, 95% CI: 1.02-1.71), and total number of partners (AOR: 1.14, 95% CI: 1.03-1.28). 3. STIs: Participants who had at least one STI (40.5%) were associated with total partner number (AOR 1.17, 95% CI: 1.06-1.30), and testing HIV positive (AOR: 1.88, 95% CI 1.41-2.50). 4. FGS: FGS prevalence (19.7%) was associated with previous anti-schistosomal treatment (AOR: 2.18, 95% CI: 1.57-3.05).

CONCLUSION

There is a high prevalence of pregnancy, HIV, STIs and FGS among sexually active young women in rural KwaZulu-Natal. Multidisciplinary approaches are urgently needed for educational and health literacy programs prior to sexual debut, and health care facilities, which should be made accessible for young women.

Evaluating diagnostic indicators of urogenital Schistosoma haematobium infection in young women: A cross sectional study in rural South Africa

BACKGROUND

Urine microscopy is the standard diagnostic method for urogenital S. haematobium infection. However, this may lead to under-diagnosis of urogenital schistosomiasis, as the disease may present itself with genital symptoms in the absence of ova in the urine. Currently there is no single reliable and affordable diagnostic method to diagnose the full spectrum of urogenital S. haematobium infection. In this study we explore the classic indicators in the diagnosis of urogenital S. haematobium infection, with focus on young women.

METHODS

In a cross-sectional study of 1237 sexually active young women in rural South Africa, we assessed four diagnostic indicators of urogenital S. haematobium infection: microscopy of urine, polymerase chain reaction (PCR) of cervicovaginal lavage (CVL), urogenital symptoms, and sandy patches detected clinically in combination with computerised image analysis of photocolposcopic images. We estimated the accuracy of these diagnostic indicators through the following analyses: 1) cross tabulation (assumed empirical gold standard) of the tests against the combined findings of sandy patches and/or computerized image analysis and 2) a latent class model of the four indicators without assuming any gold standard.

RESULTS

The empirical approach showed that urine microscopy had a sensitivity of 34.7% and specificity of 75.2% while the latent class analysis approach (LCA) suggested a sensitivity of 81.0% and specificity of 85.6%. The empirical approach and LCA showed that Schistosoma PCR in CVL had low sensitivity (14.1% and 52.4%, respectively) and high specificity (93.0% and 98.0, respectively). Using LCA, the presence of sandy patches showed a sensitivity of 81.6 and specificity of 42.4%. The empirical approach and LCA showed that urogenital symptoms had a high sensitivity (89.4% and 100.0%, respectively), whereas specificity was low (10.6% and 12.3%, respectively).

CONCLUSION

All the diagnostic indicators used in the study had limited accuracy. Using urine microscopy or Schistosoma PCR in CVL would only confirm a fraction of the sandy patches found by colposcopic examination.

Schistosoma haematobium infection and CD4+ T-cell levels: a cross-sectional study of young South African women

Schistosoma (S.) haematobium causes urogenital schistosomiasis and has been hypothesized to adversely impact HIV transmission and progression. On the other hand it has been hypothesized that HIV could influence the manifestations of schistosomiasis. In this cross-sectional study, we explored the association between urogenital S. haematobium infection and CD4 cell counts in 792 female high-school students from randomly selected schools in rural KwaZulu-Natal, South Africa. We also investigated the association between low CD4 cell counts in HIV positive women and the number of excreted schistosome eggs in urine. Sixteen percent were HIV positive and 31% had signs of urogenital schistosomiasis (as determined by genital sandy patches and / or abnormal blood vessels on ectocervix / vagina by colposcopy or presence of eggs in urine). After stratifying for HIV status, participants with and without urogenital schistosomiasis had similar CD4 cell counts. Furthermore, there was no significant difference in prevalence of urogenital schistosomiasis in HIV positive women with low and high CD4 cell counts. There was no significant difference in the number of eggs excreted in urine when comparing HIV positive and HIV negative women. Our findings indicate that urogenital schistosomiasis do not influence the number of circulating CD4 cells.

Effect of female genital schistosomiasis and anti-schistosomal treatment on monocytes, CD4+ T-cells and CCR5 expression in the female genital tract

Background

Schistosoma haematobium is a waterborne parasite that may cause female genital schistosomiasis (FGS), characterized by genital mucosal lesions. There is clinical and epidemiological evidence for a relationship between FGS and HIV. We investigated the impact of FGS on HIV target cell density and expression of the HIV co-receptor CCR5 in blood and cervical cytobrush samples. Furthermore we evaluated the effect of anti-schistosomal treatment on these cell populations.

Design

The study followed a case-control design with post treatment follow-up, nested in an on-going field study on FGS.

Methods

Blood and cervical cytobrush samples were collected from FGS negative and positive women for flow cytometry analyses. Urine samples were investigated for schistosome ova by microscopy and polymerase chain reaction (PCR).

Results

FGS was associated with a higher frequency of CD14⁺ cells (monocytes) in blood (11.5% in FGS+ vs. 2.2% in FGS-, p = 0.042). Frequencies of CD4⁺ cells expressing CCR5 were higher in blood samples from FGS+ than from FGS- women (4.7% vs. 1.5%, p = 0.018). The CD14⁺ cell population decreased significantly in both compartments after anti-schistosomal treatment (p = 0.043). Although the frequency of CD4+ cells did not change after treatment, frequencies of CCR5 expression by CD4+ cells decreased significantly in both compartments (from 3.4% to 0.5% in blood, p = 0.036; and from 42.4% to 5.6% in genital samples, p = 0.025).

Conclusions

The results support the hypothesis that FGS may increase the risk of HIV acquisition, not only through damage of the mucosal epithelial barrier, but also by affecting HIV target cell populations, and that anti-schistosomal treatment can modify this.

Safety assessment in primary Mycobacterium tuberculosis smear microscopy centres in Blantyre Malawi: a facility based cross sectional survey

INTRODUCTION

Tuberculosis (TB) is caused by Mycobacterium tuberculosis and is transmitted mainly through aerosolization of infected sputum which puts laboratory workers at risk in spite of the laboratory workers' risk of infection being at 3 to 9 times higher than the general public. Laboratory safety should therefore be prioritized and optimized to provide sufficient safety to laboratory workers.

OBJECTIVE

To assess the safety for the laboratory workers in TB primary microscopy centres in Blantyre urban.

METHODOLOGY

TB primary microscopy centers in Blantyre urban were assessed in aspects of equipment availability, facility layout, and work practice, using a standardized WHO/AFRO ISO 15189 checklist for the developing countries which sets the minimum safety score at ≥80%. Each center was graded according to the score it earned upon assessment.

RESULTS

Only one (1) microscopy center out nine (9) reached the minimum safety requirement. Four (4) centers were awarded 1 star level, four (4) centers were awarded 2 star level and only one (1) center was awarded 3 star level.

CONCLUSION

In Blantyre urban, 89% of the Tuberculosis microscopy centers are failing to provide the minimum safety to the laboratory workers. Government and other stake holders should be committed in addressing the safety challenges of TB microscopy centres in the country to ensure safety for the laboratory workers.

RECOMMENDATIONS

It is recommended that the study be conducted at the regional or national level for both public and private laboratories in order to have a general picture of safety in Tb microscopy centres possibly across the country.

Maternal body composition, HIV infection and other predictors of gestation length and birth size in Zimbabwe

The role of maternal infections, nutritional status and obstetric history in low birth weight is not clear. Thus, the objective of the present study was to assess the effects of maternal HIV infection, nutritional status and obstetric history, and season of birth on gestation length and birth size. The study population was 1669 antenatal care attendees in Harare, Zimbabwe. A prospective cohort study was conducted as part of a randomised, controlled trial. Maternal anthropometry, age, gravidity, and HIV status and load were assessed in 22nd–35th weeks gestation. Outcomes were gestation length and birth size. Birth data were available from 1106 (66·3%) women, of which 360 (32·5%) had HIV infection. Mean gestation length was 39·1 weeks with 16·6% <37 weeks, mean birth weight was 3030 g with 10·5% <2500 g. Gestation length increased with age in primigravidae, but not multigravidae (interaction, P=0·005), and birth in the early dry season, low arm fat area, multiple pregnancies and maternal HIV load were negative predictors. Birth weight increased with maternal height, and birth in the late rainy and early dry season; primi-secundigravidity, low arm fat area, HIV load, multiple pregnancies and female sex were negative predictors. In conclusion, gestation length and birth weight decline with increasing maternal HIV load. In addition, season of birth, gravidity, maternal height and body fat mass, and infant sex are predictors of birth weight.

Effect of multimicronutrient supplementation on gestational length and birth size: a randomized, placebo-controlled, double-blind effectiveness trial in Zimbabwe

BACKGROUND

Multiple micronutrient deficiencies may contribute to low birth weight, which is a major global determinant of mortality.

OBJECTIVE

We assessed the effect of prenatal multimicronutrient supplementation on gestational length and birth size.

DESIGN

We conducted a randomized, placebo-controlled, double-blind effectiveness trial among antenatal care attendees in Harare, Zimbabwe. Pregnant women (22-35 wk of gestation) were randomly allocated to receive a multimicronutrient or placebo supplement daily until delivery. Supplementation with iron and folic acid was part of antenatal care.

RESULTS

Of 1669 women, birth data were available from 1106 (66%), of whom 360 (33%) had HIV infection. The mean gestational length was 39.1 wk, and 16.6% of the women had a gestational length < 37 wk. The mean birth weight was 3030 g, and 10.5% of the infants had a birth weight < 2500 g. Multimicronutrient supplementation was associated with tendencies for increased gestational length (0.3 wk; 95% CI: -0.04, 0.6 wk; P = 0.06), birth weight (49 g; -6, 104 g; P = 0.08), and head circumference (0.2 cm; -0.02, 0.4 cm; P = 0.07) but was not associated with low birth weight (birth weight < 2500 g) (relative risk: 0.84; 0.59, 1.18; P = 0.31). The effect of multimicronutrient supplementation on birth weight was not significantly different between HIV-uninfected (26 g; -38, 91 g) and HIV-infected (101 g; -3, 205 g) subjects (interaction, P > 0.10).

CONCLUSION

Antenatal multimicronutrient supplementation may be one strategy to increase birth size.

Predictors and reference values of CD4 and CD8 T lymphocyte counts in pregnancy: a cross sectional study among HIV negative women in Zimbabwe

OBJECTIVE

To identify predictors and define reference values for T lymphocyte subsets in HIV negative pregnant black women.

DESIGN

Cross sectional study.

SETTING

Edith Opperman Martenity Hospital, Harare, Zimbabwe.

STUDY POPULATION

1113 HIV negative women 22 to 35 weeks pregnant registering for routine antenatal care.

METHODS

A questionnaire was used to collect demographic and obstetric data. CD4 and CD8 T lymphocyte counts were determined by manual immunocytochemistry. Concentrations in serum, of retinol, beta-carotene, ferritin, folate and 1-antichymotrypsin were also measured. Multiple linear regression analysis was employed to identify and estimate effects of potential predictors.

MAIN OUTCOME MEASURES

CD4 and CD8 T lymphocyte levels, demographic, obstetric data and micronutrient status.

RESULTS

Predictors of CD4 counts were gestational age, serum retinol and season. CD4 counts declined by 25 (95% confidence interval [CI]; 11 to 40; p = 0.001) cells/L for each week's increase in gestation among women with low serum retinol, while low serum retinol was independently associated with lower CD4 counts (-127; 95% CI, -233 to 20 cells/L; p = 0.02) at 35 weeks gestation. The late rainy season was associated with higher CD4 counts (137; 95% CI, 67 to 207 cells/L; p < 0.001). CD8 counts were higher in women with low serum folate (87; 95% CI, 6 to 166 cells/L; p = 0.036) and were slightly higher in gravida 4+ compared to gravida one to three. Reference values of CD4 but not CD8 count and percentage markedly differed from flow cytometry values of pregnant and non-pregnant women in developed and developing countries reported in the literature, even after controlling for the differences in methods of T lymphocyte subset immunophenotyping.

CONCLUSION

Gestational age, gravidity, micronutrient status and season influence T lymphocyte subset levels and need to be considered when designing clinical management and intervention strategies for pregnant women. The data underscores the need for local reference values.

Iron, haptoglobin phenotype, and HIV-1 viral load: a cross-sectional study among pregnant Zimbabwean women

BACKGROUND

Viral load is a determinant of HIV-1 progression and transmission. Iron status and the phenotype of haptoglobin, a heme-binding acute phase reactant, may be determinants of viral load. We aimed to describe the effect of iron status, haptoglobin phenotype (Hp), and other predictors on HIV-1 viral load.

METHODS

Based on a cross-sectional study among 1669 antenatal care attenders (22-35 weeks) in Zimbabwe, 526 (31.5%) were found to be HIV infected. The role of season, age, gravidity, gestational age, malaria parasitemia, Hp, and elevated serum alpha(1)-antichymotrypsin (ACT) as well as serum ferritin, folate, retinol, and beta-carotene on HIV viral load among the 526 HIV-infected women was assessed using multiple linear regression analysis.

RESULTS

The distribution of Hp 1-1 (32%), Hp 2-1 (48%), and Hp 2-2 (20%) was not different from that of 53 uninfected women. Mean viral load was 3.85 log(10) (95% CI: 3.77-3.93) genome equivalents (geq)/mL, ranging from 3.77 (95% CI: 3.64-3.90) geq/mL in women with Hp 1-1 to 4.05 (95% CI: 3.81-4.21) geq/mL in women with Hp 2-2. With elevated serum ACT controlled for, women with Hp 2-2 had viral loads twice (95% CI: 1.4-4.0, p =.002) that of women with Hp 1-1, whereas those with serum ferritin <6 micro g/L had viral loads less than one third (95% CI: 0.13-0.53, p =.013) that of women with serum ferritin >24 micro g/L. Viral loads were also higher in women enrolled in the early rainy season compared with the dry season, in gravidae 4+ compared with gravidae 1 through 3, and in those with moderately elevated compared with low serum alpha(1)-antichymotrypsin, but neither age, gestational age, serum folate, serum retinol, nor serum beta-carotene were predictors.

CONCLUSION

Storage iron, Hp 2-2, and elevated ACT are independent positive predictors of HIV-1 viral load. The positive relationship between serum ferritin and viral load was not the result of an acute phase response or iron accumulation with advanced HIV infection. A possible detrimental role of iron in HIV infection would have serious public health implications.

Subclinical mastitis among HIV-infected and uninfected Zimbabwean women participating in a multimicronutrient supplementation trial

Subclinical mastitis, defined as raised milk sodium/potassium (Na/K) ratio is common and associated with poor infant growth and increased mother-to-child HIV transmission. In 1996-97, we conducted a randomized controlled trial of multiple micronutrient supplementation, at recommended daily allowance levels, from 22 to 35 weeks gestation until 3 months post-partum, on the prevalence and severity of subclinical mastitis among 84 HIV-infected and 83 HIV-uninfected lactating Zimbabwean women and on their infants' growth. Spot milk samples collected before 4.5 months post-partum were analysed for Na/K ratio by flame photometry. There was no significant difference in prevalence of subclinical mastitis between HIV-infected and HIV-uninfected women. After controlling for infant age at time of sampling, micronutrient-supplemented HIV-infected women had non-significantly (P = 0.08) lower geometric mean Na/K ratio (0.43, 95% CI 0.35-0.51) than HIV-infected women given placebo (0.51, 95% CI 0.42-0.61). Micronutrient supplementation had no effect on the prevalence of subclinical mastitis among HIV-uninfected women (odds ratio [OR] = 1.26, 95% CI 0.45-3.51, P = 0.80) but induced a borderline decrease in prevalence (OR = 2.82, 95% CI 0.96-8.26, P = 0.07) among HIV-infected women. Infant weight between 1.5 and 4.5 months was lower in women with higher milk Na/K ratio. Thus, the importance of subclinical mastitis for infant growth suggests that further investigations to decrease the condition, perhaps using higher micronutrient doses, are warranted.

HIV-1 viral load and elevated serum alpha(1)-antichymotrypsin are independent predictors of body composition in pregnant Zimbabwean women

Human immunodeficiency virus (HIV) infection affects body composition, but their relationship has not been studied in pregnant women. We conducted a cross-sectional study among 1669 women receiving antenatal care between 22 and 35 wk of gestation in Harare, Zimbabwe. The role of HIV-1 status and viral load, malaria and elevated serum alpha(1)-antichymotrypsin (ACT, an acute phase protein) in weight, body mass index (BMI), arm circumference (AC), triceps skinfold thickness (TSF), and arm muscle (AMA) and fat (AFA) area were assessed using multiple linear regression analysis. The mean (range) age was 24.4 (14-45) y and gestational age 29 (22-35) wk. HIV infection was present in 31.5% of the women, malaria parasitemia in 0.4% and 11.4% had serum ACT >0.4 g/L. There was no difference in any anthropometric variable between HIV-infected and uninfected women. However, women with viral loads (genome equivalents/mL) between 4 and 5 and >5 log(10) had 1.1 [95% confidence interval (CI): -0.3, 2.3] and 2.5 (95% CI: 0.1, 5.1) kg lower weights compared with uninfected women; this was explained by losses of both AFA and AMA. Malaria parasitemia was associated with 6 cm(2) (95% CI: 0.4; 11.8) or 25% lower AMA. Elevated serum ACT was a negative predictor of all anthropometric variables, i.e., levels between 0.3 and 0.4, 0.4 and 0.5 and >0.5 g/L were associated with 1, 2 and 6 kg lower mean body weights, respectively. Despite the limitations of a cross-sectional design, we conclude that arm fat and muscle areas, reflecting body fat and lean body mass, seem to be unaffected in the majority of HIV-infected pregnant women, but decline with increasing viral loads. The effects of viral load are not explained by elevated serum ACT, which is a strong independent predictor of all anthropometric variables.

Does the first pregnancy precipitate age-related fat deposition?

Excessive accumulation of fat in women of childbearing age is a concern, since obesity is an important cause of morbidity and mortality. Deposition of fat during pregnancy, which is not metabolized during lactation, may contribute. However, the individual effects of age and gravidity on fat accumulation have not been disentangled. Based on multiple linear regression analysis of anthropometric data from 1113 pregnant women from Zimbabwe, we found evidence to suggest that fat deposition is an effect of age rather than gravidity that is precipitated by the first pregnancy.

Genetic diversity of a population of Schistosoma haematobium derived from schoolchildren in east central Zimbabwe

To characterize the extent of genetic diversity of Schistosoma haematobium within and among its definitive host (intra- and interhost parasite diversity), 133 individual isolates from 25 infected schoolchildren were compared using randomly amplified polymorphic DNA markers. With 4 primers, 53 unambiguous loci were identified, and of these, 22 were polymorphic. Mean heterozygosity in the population was 0.116 +/- 0.043. Analysis of molecular variance showed the majority of variance occurred within, rather than between, hosts. Frequencies of certain alleles segregated the parasite population into 13 distinct clusters of associated genotypes, with 4 of these first appearing 10 mo after the initial survey. Considering the level of diversity within this limited geographical area and the possibility of rapid turnover of genotypes, parasite variance may impact acquired immunity and clinical outcome of the infection.

HIV and other predictors of serum beta-carotene and retinol in pregnancy: a cross-sectional study in Zimbabwe

BACKGROUND

Vitamin A status during pregnancy is important to maternal and infant health.

OBJECTIVE

Our goal was to identify predictors of serum beta-carotene and retinol.

DESIGN

This was a cross-sectional study of 1669 women (22-35 wk of gestation) in Harare, Zimbabwe, who were receiving prenatal care. The statistical effects of age, season, gestational age, gravidity, HIV-1 infection, malaria parasitemia, and serum alpha1-antichymotrypsin (ACT) on serum beta-carotene (log10 transformed) and retinol were estimated by using multiple linear regression analyses.

RESULTS

HIV infection was found in 31.5% of the women; 0.4% had malaria. Serum beta-carotene concentrations (geometric x: 0.19 micromol/L) were lower in HIV-infected women than in uninfected women (10beta = 0.78; 95% CI: 0.72, 0.84) and increased with age (10beta = 1.05; 1.02, 1.07) in gravida 1 but not in gravida > or =2 (P for interaction = 0.00002). Serum retinol (x: 0.92 micromol/L) increased with age (beta = 0.004; 0.0001, 0.008) in uninfected women but not in HIV-infected women (P for interaction = 0.02) and was 0.05-micromol/L (0.02, 0.09) lower in HIV-infected women than in uninfected women at 24 y of age. Furthermore, gestational age, season, use of prenatal supplements, and malaria were predictors of serum beta-carotene. Serum retinol was lower in women carrying male (beta = -0.04; -0.08, -0.00005) and multiple (beta = -0.21; -0.35, -0.08) fetuses. Serum ACT concentrations of 0.3-0.4, 0.4-0.5, and >0.5 g/L were associated with 3%, 11%, and 44% lower serum beta-carotene and 0.04-, 0.15-, and 0.41-micromol/L lower serum retinol. Serum ACT (g/L) was higher in women with malaria than in those without (beta = 0.10; 0.03, 0.16) and in gravida 1 than in gravida > or =2 (beta = 0.012; 0.003, 0.021), but was not higher in HIV-infected women than in uninfected women (beta = 0.001; -0.008, 0.011).

CONCLUSIONS

HIV infection, malaria, gravidity, and gestational age were predictors of serum beta-carotene and retinol. Serum ACT was an important predictor of both and was associated with gravidity and gestational age.

HIV and other predictors of serum folate, serum ferritin, and hemoglobin in pregnancy: a cross-sectional study in Zimbabwe

BACKGROUND

Folate and iron status and hemoglobin concentrations are important to maternal and infant health.

OBJECTIVE

Our goal was to identify predictors of serum folate, serum ferritin, and hemoglobin.

DESIGN

This was a cross-sectional study of 1669 pregnant women (22-35 wk of gestation) in Harare, Zimbabwe, who were receiving prenatal care. The statistical effects of age, season, gestational age, gravidity, HIV-1 infection, malaria parasitemia, and serum alpha1-antichymotrypsin (ACT) on serum folate, serum ferritin (log10 transformed), and hemoglobin were estimated by using multiple linear regression analyses.

RESULTS

Serum folate (x: 11.4 micromol/L) was 0.52-nmol/L (95% CI: 0.04, 1.0) lower in HIV-infected women than in uninfected women and 0.65-nmol/L (0.014, 1.28) lower in weeks 25-35 than in weeks 22-25. Serum ferritin (geometric x: 11.6 microg/L) was 0.93 times (0.86, 0.99) lower in HIV-infected women and 2.25 times (1.41, 3.61) higher in women with malaria parasitemia than in uninfected women. Similarly, serum ferritin was 0.71 times (0.63, 0.79) higher in weeks 32-35 than in weeks 22-25 and 1.21 times (1.12, 1.29) higher in gravida > or =3 than in gravida 1. Elevated serum ACT was a strong predictor of serum folate, serum ferritin, and hemoglobin. HIV infection was associated with a 12.9-g/L (8.9, 16.8) lower hemoglobin concentration in women with nondepleted iron stores but low serum retinol and a 7-8-g/L lower hemoglobin concentration in women with other combinations of serum ferritin and retinol (P for interaction = 0.038). Season, age, gestational age, and gravidity were not significant predictors of hemoglobin. Low serum folate, ferritin, and retinol were associated with low hemoglobin.

CONCLUSIONS

HIV was associated with lower serum folate, serum ferritin, and hemoglobin. HIV infection was also associated with lower hemoglobin, particularly in women with stored iron and low serum retinol. Low serum folate, ferritin, and retinol were associated with low hemoglobin.

Enumeration of CD4 and CD8 T-cells in HIV infection in Zimbabwe using a manual immunocytochemical method

OBJECTIVES

To enumerate CD4 and CD8 T-cells using the simple and cheap immuno-alkaline phosphatase (IA) method and to compare it with flow cytometry (FC); and to study the effects of duration of sample storage on the IA method results.

DESIGN

Method comparison study.

SETTING

Blair Research Laboratory, Harare, Zimbabwe.

SUBJECTS

41 HIV positive and 11 HIV negative men and women from Harare participating in HIV studies at Blair Research Laboratory, Zimbabwe.

MAIN OUTCOME MEASURES

CD4 and CD8 T-cell counts by FC and the IA method.

RESULTS

The IA method and FC were highly correlated for CD4 counts (Spearman rs = 0.91), CD4 percentage (rs = 0.84), CD8 count (rs = 0.83), CD8 percentage (rs = 0.96) and CD4/CD8 ratio (rs = 0.89). However, CD4 cell counts and percentage measured by the IA method were (mean difference +/- SE) 133 +/- 24 cells/microL [corrected] and 6.7 +/- 1.1% higher than those measured by the FC method (p < 0.0001) respectively. CD8 counts and percentages by the IA method were lower than those by the FC method (p < 0.01). Accordingly, the IA method gave a higher CD4/CD8 ratio (p < 0.01). IA method CD4 counts < 300/mL best predicted FC CD4 counts < 200/mL while IA CD4% < 25 best predicted FC CD4% < 14%. IA method CD4/CD8 ratio < 0.8 best predicted FC CD4/CD8 ratio < 0.5. Smears stored for up to 18 months gave results similar to fresh smears.

CONCLUSION

The IA method correlates well with but gives CD4 counts and percentages that are higher than those determined by FC. On the contrary, the IA method gives CD8 counts and percentage that are lower than FC values. The method is a cheap and reliable alternative to FC and allows storage of samples for extended periods before analysis, making it an appropriate technology for resource poor countries.

Comparative evaluation and assessment of the diagnostic usefulness of four commercial HIV-1/HIV-2 antibody assays using two well-characterized serum panels from Blood Transfusion Service and the National Health Laboratory Services in Zimbabwe

OBJECTIVE

To evaluate four Enzyme Linked Immunosorbent Assay (ELISA) HIV kits for possible use as a combination at the National Health Laboratory Services (NHLS) in Zimbabwe.

DESIGN

Laboratory evaluation, sensitivity, specificity and cost effectiveness of HIV diagnostic kits.

SETTING

Blood Transfusion Service (BTS) and Parirenyatwa Hospital in Zimbabwe.

SUBJECTS

A total of 346 samples from 245 patients referred to Parirenyatwa Hospital and 101 blood donors at BTS.

MAIN OUTCOME

The main goal was to come out with the best combination of ELISA kits in terms of sensitivity, specificity and cost effectiveness for use in diagnosis of HIV infection in Zimbabwe.

RESULTS

The best combination kit was the Murex/Innotest with 100% sensitivity and 98.9% specificity, being slightly superior to the Genelavia/Vironostika combination kits in current use at NHLS. In addition, the Murex/Innotest combination has the shortest assay running time and requires fewer internal controls thereby increasing the number of test specimens per run.

CONCLUSION

We recommend the use of the Murex/Innotest kits as a suitable combination for HIV infection diagnosis in Zimbabwe. The combination has a relatively low number of discordant results, drastically reducing the cost of running a third confirmatory test to resolve the discordant results. Most importantly, this combination maximizes HIV infection diagnosis by its ability to detect antibodies to HIV-1 groups M and O as well as HIV-2.

The impact of zinc supplementation on growth and body composition: a randomized, controlled trial among rural Zimbabwean schoolchildren

OBJECTIVES

To assess the effect of zinc supplementation on growth and body composition among schoolchildren.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING AND SUBJECTS

313 rural Zimbabwean schoolchildren (144 boys and 169 girls, 11-17 y).

INTERVENTIONS

Supplementation with zinc (30 or 50 mg) or placebo on schooldays for 12 months. Due to drought, a food programme was in operation during the last eight months of the study.

VARIABLES

Weight, height, upper arm circumference, triceps skinfold thickness, and weight-for-age, height-for-age, weight-for-height, arm muscle-area-for-age and arm fat-area-for-age Z-scores.

RESULTS

Significant effects on weight gain (0.51 vs 0.14 kg, P = 0.01), weight-for-age Z (-0.08 vs -0.14, P = 0.01) and arm muscle area-for-age Z-score (0.10 vs 0.01, P = 0.03) were seen over the first three months, whereas no effects were seen over the full 12 months.

CONCLUSIONS

Zinc deficiency impairing lean body mass and weight gain was documented. However, the effect of zinc seen over the first three months vanished during the last nine months when the food programme was in operation. Zinc deficiency may have persisted, but another nutrient may have become growth limiting during the last nine months.

The impact of zinc supplementation on Schistosoma mansoni reinfection rate and intensities: a randomized, controlled trial among rural Zimbabwean schoolchildren

OBJECTIVES

To assess the effect of zinc supplementation on susceptibility to S. mansoni reinfections among schoolchildren.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING AND SUBJECTS

313 rural Zimbabwean schoolchildren (144 boys and 169 girls), 11-17 y).

INTERVENTIONS

Supplementation with zinc (30 or 50 mg) or placebo on schooldays for 12 months. Due to drought, a food programme was in operation during the last eight months of the study.

OUTCOME MEASURES

S. mansoni and S. haematobium reinfection rates and intensities.

RESULTS

There was no difference in reinfection rates between the zinc and placebo groups (25 vs 29%, P = 0.46). However, the median intensity of S. mansoni reinfection, although low in both groups, was significantly lower in the zinc than in the placebo group (7 vs 13 eggs per gram of faeces, P = 0.048). No difference in either S. haematobium reinfection rates or intensities were seen.

CONCLUSIONS

Zinc supplementation reduced the intensity of S. mansoni reinfections. Although the intensities of reinfection were very low, the finding probably reflects a biological effect of zinc that could be of public health importance in settings with higher transmission.

Ultrasonographic assessment of Schistosoma mansoni and S haematobium morbidity in Zimbabwean schoolchildren

Ultrasound examinations for Schistosoma haematobium - and S. mansoni-related morbidity were done in 174 schoolchildren from a subsistence farming community in southern Zimbabwe. The examinations were done according to the standardized protocol elaborated by the Cairo Working Group (the Cairo classification) and the Managil classification. Forty-six percent of the children had grade I periportal thickening (PPT) on ultrasound according to the Cairo classification, but none had grade II or higher. The significance of grade I PPT in the Cairo classification is questionable, since there were no differences between those without and those with grade I PPT with respect to intensity of S. mansoni infection or liver size. The prevalence of grade I PPT according to the Managil classification was 10%, and no association between the two classifications was seen. In multiple regression analysis, S. mansoni egg output was found to be a significant predictor of liver size, when controlling for height and sex. An interaction between S. haematobium and S. mansoni infection is suggested because the positive relationship between S. mansoni and liver size was seen in the presence but not in the absence of S. haematobium infection.

Serum concentration of micronutrients in relation to schistosomiasis and indicators of infection: a cross-sectional study among rural Zimbabwean schoolchildren

OBJECTIVE

To study the relation between indicators of infection and Schistosoma mansoni and S. haematobium infection, and serum concentrations of zinc, ferritin and retinol.

DESIGN

Cross-sectional.

SETTING AND SUBJECTS

313 rural Zimbabwean schoolchildren (144 boys and 169 girls, 11-17 years).

VARIABLES

S. mansoni and S. haematobium egg output, concentration of C-reactive protein, neutrophil count, questionnaire data on fever and diarrhoea, and serum concentrations of retinol, ferritin and zinc.

RESULTS

Age, elevated CRP, fever and S. mansoni egg output were significant predictors of the concentration of retinol. The regression coefficient for age was positive, and negative for elevated CRP, fever and S. mansoni egg output. As S. mansoni, but not S. haematobium, was of significance, it is unlikely that low retinol level increased susceptibility to infection. The effect of S. mansoni on retinol level was 0.03 mumol/l (95% CI: 0.002-0.06, P = 0.03) for each 100 eggs/g increase in egg output. Neither indicators of infection nor age and sex were predictors of concentration of zinc and log10 concentration of ferritin.

CONCLUSION

S. mansoni infection reduced retinol level, when indicators of infection and age were controlled for. High intensities of S. mansoni infection may induce vitamin A deficiency among children with marginal vitamin A status. The study emphasizes the importance of controlling for age and metabolic response to concurrent infections in studies using serum retinol as a measure of vitamin A status.

Circulating anodic antigen (CAA) levels in different age groups in a Zimbabwean rural community endemic for Schistosoma haematobium determined using the magnetic beads antigen-capture enzyme-linked immunoassay

A simplified version of the magnetic bead antigen-capture enzyme-linked immunoassay (MBAC-EIA) was used to detect circulating anodic antigen (CAA) in individuals of different age groups with Schistosoma haematobium infection only in an endemic area of Zimbabwe. An overall positive correlation between S. haematobium egg excretion and CAA levels was demonstrated. The age profile for CAA levels was generally comparable with the age profile of S. haematobium prevalence and intensity of infection. The CAA levels were higher in younger (5-14 years of age) individuals than in older (greater than 14 years of age) ones. Since the sensitivity of the MBAC-EIA in the diagnosis of S. haematobium infection was found to be 97%, CAA levels appear to be a useful indicator of worm burden in an endemic area.

Ultrasonographic organometry: liver and spleen dimensions among children in Zimbabwe

Attempts have been made to develop a staging system of sonographic Schistosoma mansoni morbidity for use in epidemiological studies and for evaluation of control programmes. Therefore, normal dimensions of livers and spleens in children in countries with endemic S. mansoni infections need to be established. Normal dimensions of livers and spleens are presented, based on examination of 144 Zimbabwean children between 8 and 16 years of age found to be S. mansoni egg negative 12 months after treatment with praziquantel. Based on the liver and spleen measurements, an index of liver size and the spleen volume were calculated. Height was employed as the independent variable in all multiple regression models. The organometric data are presented as prediction plots, with observed values and fitted regression line with 95% confidence and prediction intervals. The mean spleen volume was 30% larger for boys than for girls, whereas there was no consistent difference in liver size. No effect of growth Z-scores was seen. The measurements were compared with normal dimensions of livers of German children. For a given height, the mean index of liver size was lower in Zimbabwean than in German children, but inter-observer variation could be a possible explanation for this difference.

Age-related antibody profiles in Schistosoma haematobium infections in a rural community in Zimbabwe

Antibody responses to soluble Schistosoma haematobium egg (SEA) and worm (SWA) antigens in a rural Zimbabwean study population were examined by ELISA. One hundred and sixteen S. haematobium infected and 124 non-infected individuals representing individuals greater than five years old, were included. Non-endemic control sera were obtained from a schistosomiasis non-endemic part of Zimbabwe and from Norwegian blood donors. A possible association between IgE antibody responses and resistance to S. haematobium infection was indicated by a negative correlation between IgE anti-SEA levels and intensity of S. haematobium infection, and by a positive correlation between IgE responses to SEA and SWA and age. Similarly, an association between IgA and anti-SWA and resistance to S. haematobium was suggested by a negative correlation to intensity of infection and a positive correlation with age. A probably association between IgM and IgG4 with susceptibility to S. haematobium infection was described; intensity of S. haematobium infection correlated positively with IgG, IgG4 and IgM responses to SEA and with IgG4 and IgM responses to SWA, also age correlated negatively with IgG4 and IgM responses to SEA and with IgG4 responses to SWA. These findings support the concept of IgG4 and IgM as blocking antibodies. Significant positive correlations between antibody responses to SEA and SWA suggests cross-reactivity between eggs and adult worms. In addition, the recognition by IgE and IgG4 of the same schistosomulum antigens in immunoblotting suggests competitions for the same antigens.

Optimization of the Magnetic Bead Antigen Capture Enzyme Immuno Assay for the detection of circulating anodic antigens in mixed Schistosoma infections

In the present study, simplification and adaptation of the Magnetic Bead Antigen Capture Enzyme Immuno Assay (MBAC-EIA) technique for detection of circulating anodic antigens (CAA) under field conditions was achieved. It was shown that the assay could be performed successfully within the broad temperature range of 18-37 degrees C. The slightly lower sensitivity observed at low temperatures could be adjusted for by prolonging the incubation period. Shaking the plate by hand was as good as automatic mechanical shaking, aspiration of the supernatant before the addition of conjugate was not necessary, and the use of whole blood and serum offered similar assay sensitivity. Furthermore incubation times could be considerably shortened without loss of sensitivity. A major advantage of the MBAC-EIA was that the beads, after elution of bound components, were found to be reusable. The study also showed that the sensitivity of the MBAC-EIA technique in diagnosis of schistosomiasis in a Zimbabwean community endemic for both urinary and intestinal schistosomiasis, was 94%.

Progress in the control of schistosomiasis in Zimbabwe since 1984

Schistosomiasis remains the second most important parasitic disease in Zimbabwe. In terms of its combined morbidity and prevalence, schistosomiasis is thought to be the most important helminth infection of man. Since 1984, a number of control programmes have commenced around the country and a national control programme aimed at reducing morbidity is being implemented. The strategy adopted in Zimbabwe is a community based approach integrated in the primary health care system.

Control of schistosomiasis transmission in newly established smallholder irrigation schemes

The extent to which schistosomiasis can be controlled through careful design of the irrigation works, the operation schedule, the location of villages and the provision of safe water supplies and sanitation in smallholder irrigation schemes at Mushandike in south-east Zimbabwe is reported. The schemes provide land for 400 peasant families who are monitored for schistosomiasis soon after resettlement. Between April 1986 and August 1987 there was a marked reduction in overall prevalence following treatment. For Schistosoma haematobium, the reductions in 2 schemes were 53% and 82% and for S. mansoni, 82% and 100%, in spite of transmission in settlements upstream from the schemes. In contrast, in a nearby irrigated farm where no control measures were introduced, S. haematobium prevalence declined by only 31% while that for S. mansoni increased by 22% a year following treatment. These results are supported and strengthened by measurements of snail population sizes and their infection rates, cercarial densities in the water and incidence data for the human population, and suggest that the engineering and environmental control measures introduced are significant means of controlling transmission in smallholder irrigation schemes with the lowest recurrent costs.