Determinants of anemia in postpartum HIV-negative women in Dar es Salaam, Tanzania

OBJECTIVE

The determinants of anemia during both pregnancy and postpartum recovery remain incompletely understood in sub-Saharan African women.

SUBJECTS/METHODS

In a prospective cohort study among pregnant women, we assessed dietary, biochemical, anthropometric, infectious and sociodemographic factors at baseline. In multivariate Cox proportional hazards models, we examined predictors of incident anemia (hemoglobin <11 g/dl) and iron deficiency anemia (anemia plus mean corpuscular volume <80fL), and recovery from anemia and iron deficiency anemia through 18 months postpartum at antenatal clinics in Dar es Salaam, Tanzania between 2001 and 2005. A total of 2364 non-anemic pregnant women and 4884 anemic women were enrolled between 12 and 27 weeks of gestation.

RESULTS

In total, 292 women developed anemia during the postpartum period and 165 developed iron deficiency anemia, whereas 2982 recovered from baseline anemia and 2044 from iron deficiency anemia. Risk factors for postpartum anemia were delivery complications (RR 1.6, 95% confidence interval (CI) 1.13, 2.22) and low postpartum CD4 cell count (RR 1.73, 95% CI 0.96, 3.17). Iron/folate supplementation during pregnancy had a protective relationship with the incidence of iron deficiency anemia. Absence of delivery complications, education status and iron/folate supplementation were positively associated with time to recovery from iron deficiency.

CONCLUSION

Maternal nutritional status during pregnancy, prenatal iron/folate supplementation, perinatal care, and prevention and management of infections, such as malaria, are modifiable risk factors for the occurrence of, and recovery from, anemia.

The use of total lymphocyte count as a surrogate for low CD4+ T lymphocyte cell counts among HIV-1-infected women in Tanzania

BACKGROUND

Human Immunodeficiency Virus type 1 (HIV-1) infection leads to a progressive decline in CD4+ T-lymphocyte (CD4) cells. Initiation of prophylaxis against Opportunistic infections in adults (CD4% used for children) and antiretroviral therapy is usually based on CD4 cell counts, but CD4 cell counts measurement is not affordable in most African countries.

OBJECTIVE

To examine whether total lymphocyte counts (TLC) may be used as proxies for low CD4 cell counts.

DESIGN

Cross-sectional at baseline when women were pregnant and at least six months postpartum.

METHODS

1,078 HIV-1-infected pregnant women from Dar es Salaam, Tanzania were enrolled in a randomized clinical trial. A series of receiver operator characteristic (ROC) curves were created at baseline and at least 6 months postpartum and among women in WHO Stage 3 and above. The sensitivity and specificity of TLC and hemoglobin in predicting an absolute CD4 count < 200 cells/mm3 were determined for various clinically relevant cut points.

RESULTS

TLC was not a good predictor of low CD4 cell counts during pregnancy or at least six months postpartum as exhibited by low ROC Area Under the Curve (AUCs) of .57 and .62 respectively. No other variable had the ability to predict CD4 < 200 cells/mm3.

CONCLUSIONS

The use of TLC as a proxy for the estimation of low CD4 cell counts in a population of HIV-1-infected adults from sub-Saharan Africa was not substantiated. Inexpensive methods to quantify CD4 cell counts in Africa are needed.

Genital tract infections among HIV-infected pregnant women in Malawi, Tanzania and Zambia

SUMMARY

The aim of this study was to compare the prevalence and factors associated with genital tract infections among HIV-infected pregnant women from African sites. Participants were recruited from Blantyre and Lilongwe, Malawi; Dar es Salaam, Tanzania; and Lusaka, Zambia. Genital tract infections were assessed at baseline. Of 2627 eligible women enrolled, 2292 were HIV-infected. Of these, 47.8% had bacterial vaginosis (BV), 22.4% had vaginal candidiasis, 18.8% had trichomoniasis, 8.5% had genital warts, 2.6% had chlamydia infection, 2.2% had genital ulcers and 1.7% had gonorrhoea. The main factors associated with genital tract infections included genital warts (adjusted odds ratio [AOR] 1.8, 95% CI 1.2-2.7), genital ulcers (AOR 2.4, 95% CI 1.2-5.1) and abnormal vaginal discharge (AOR 2.5, 95% CI 1.9-3.3) for trichomoniasis. BV was the most common genital tract infection followed by candidiasis and trichomoniasis. Differences in burdens and risk factors call for enhanced interventions for identification of genital tract infections among HIV-infected women.

Socio-economic and demographic factors associated with prevalence of HIV infection among pregnant women in Dar es Salaam, Tanzania

BACKGROUND

HIV/AIDS epidemic has become generalised in low resource settings in sub-Saharan Africa where 90% of all maternal-foetal transmission of HIV infection occurs. Global effort to scale-up pMTCT is underway, however, mechanisms to maximise screening of HIV- 1 positive women for Nevirapine treatment and other interventions, are not clear.

OBJECTIVE

To identify socioeconomic and demographic characteristics associated with the prevalence of HIV- 1 infection among Tanzanian women.

DESIGN

Cross-sectional study.

SETTING

Four antenatal clinics in Dar es Salaam.

RESULTS

HIV prevalence rate was 13.1 (95% confidence interval (CI): 12.7% - 13.5%) and it increased with increasing maternal age. Older age than 25, mid-arm circumference less than 25cm, geographic location, working in a public house, and partner's occupation were independently associated with higher prevalence of infection. Women in monogamous marriages were 77% less likely to be HIV infected compared to women with no regular partner. Similarly, women with more than five persons per household, and those who spent less on food had a significantly lower HIV prevalence.

CONCLUSION

HIV infection is sufficiently widespread among women in Dar es Salaam suggesting that screening based on socioeconomic and demographic characteristics would miss a large proportion of the positives. There is need to increase facilities for counselling and testing using an opt-out approach for testing in all antenatal clinics in the city.

Zinc supplementation to HIV-1-infected pregnant women: effects on maternal anthropometry, viral load, and early mother-to-child transmission

OBJECTIVE

To examine the effect of zinc supplementation to HIV-1-infected pregnant women on viral load, early mother-to-child transmission of HIV (MTCT), and wasting.

DESIGN

Double-blind placebo-controlled randomized clinical trial.

SETTING

Antenatal clinic in Dar es Salaam, Tanzania.

SUBJECTS

Four hundred HIV-1-infected pregnant women.

METHODS

Women 12-27 weeks of gestation were randomly assigned to receive a daily oral dose of 25 mg zinc or placebo from the day of the first prenatal visit until 6 weeks postdelivery. Weight and mid-upper arm circumference (MUAC) were measured monthly. HIV status of the babies was assessed at birth and at 6 weeks postpartum. Viral load was assessed in a random sample of 100 women at baseline and at the end of the study.

RESULTS

Zinc had no effects on maternal viral load or early MTCT. Supplementation was related to a significant threefold increase in the risk of wasting (reaching a MUAC value <22 cm) during an average 22 weeks of observation (RR=2.7, 95%CI=1.1, 6.4, P=0.03), and to a 4 mm decline in MUAC during the second trimester (P=0.02).

CONCLUSIONS

Zinc supplementation to HIV-infected pregnant women offers no benefits on viral load or MTCT. The clinical relevance of an apparent decrease in MUAC associated with zinc supplementation is yet to be ascertained. These findings together with the lack of effect on fetal outcomes (reported previously) do not provide support for the addition of zinc supplements to the standard of prenatal care among HIV-infected women.

Predictors of incident tuberculosis among HIV-1-infected women in Tanzania

SETTING

The development of tuberculosis (TB) in HIV-1-infected individuals is associated with accelerated HIV-1 disease progression.

OBJECTIVE

To examine the predictors of incident TB in HIV-1-infected Tanzanian women.

DESIGN

A prospective cohort of 1078 HIV-1-infected pregnant women was enrolled in a randomized clinical trial to examine the role of vitamin supplements in HIV-1 disease progression and fetal outcomes.

RESULTS

Of 1008 women evaluated for TB, 88 (8.7%) developed TB. After controlling for age, education and hemoglobin concentration, in multivariate analysis, low CD4 cell count, elevated erythrocyte sedimentation rate (ESR), decreased mid-upper arm circumference, and high viremia were associated with an increased risk of TB. CD4 <200 vs. > or = 500 cells/mm3 was associated with a 4.44-fold increase in risk of TB (95%CI 2.10-9.40). Individuals with high viremia (> or = 50,000 copies/ml) had a 2.43-fold increase in risk of TB (95%CI 1.24-4.76). Elevated malarial parasite density was slightly associated with a 65% (95%CI 19-85) decreased risk of TB.

CONCLUSIONS

The risk of developing TB was elevated among women with low CD4 cell counts, elevated ESR, coinfections with other pathogens, poor nutrition and high viremia. There is a slight inverse association between malarial infection and TB, possibly because treating malaria may reduce the risk of TB.

Effect of vitamin supplementation to HIV-infected pregnant women on the micronutrient status of their infants

OBJECTIVE

We examined whether supplementation with vitamin A and/or vitamins B, C, and E to HIV-infected women during pregnancy and lactation is related to increased concentrations of vitamins A, B12, and E in their infants during the first 6 months of life.

DESIGN

We carried out a randomized clinical trial among 716 mother-infant pairs in Dar-es-Salaam, Tanzania. Women were randomly allocated to receive a daily oral dose of one of four regimens: vitamin A, multivitamins (B, C, and E), multivitamins including A, or placebo. Supplementation started at first prenatal visit and continued after delivery throughout the breastfeeding period. The serum concentration of vitamins A, E and B12 was measured in infants at 6 weeks and 6 months postpartum.

RESULTS

Maternal vitamin A supplementation increased serum retinol in the infants at 6 weeks (mean difference=0.09 micromol/l, P<0.0001) and 6 months (mean difference=0.06 micromol/l, P=0.0002), and decreased the prevalence of vitamin A deficiency, but had no impact on serum vitamins E or B12. Multivitamins increased serum vitamin B12 at 6 weeks and 6 months (mean differences=176 pmol/l, P<0.0001 and 127 pmol/l, P<0.0001, respectively) and vitamin E (mean differences=1.8 micromol/l, P=0.0008 and 1.1 micromol/l, P=0.004, respectively) and decreased the prevalence of vitamin B12 deficiency.

CONCLUSIONS

Vitamin supplementation to HIV-1-infected women is effective in improving the vitamin status of infants during the first 6 months of age.

HIV status and sociodemographic correlates of maternal body size and wasting during pregnancy

OBJECTIVE

To examine HIV status and sociodemographic variables as correlates of body size (height, body mass index (BMI), and mid-upper-arm circumference (MUAC)) and wasting (MUAC <22 cm) in pregnant women.

DESIGN

Cross-sectional study.

SETTING

Four antenatal clinics in Dar es Salaam, Tanzania.

SUBJECTS

Women presenting for first prenatal visit before the 23rd week of gestation, between April 1995 and July 1997 (n=13 760).

RESULTS

Mean MUAC, BMI and height were 25.5 cm, 23.5 kg/m(2) and 155.1 cm, respectively. The prevalence of HIV infection was 13.1% and the overall prevalence of wasting was 4.7%. Wasting was 34% (95% CI=3%, 73%) more prevalent among HIV-infected than in uninfected mothers, after adjusting for week of gestation, height and sociodemographic indicators. The risk of wasting associated with HIV infection was highest among women with low level of education or unable to contribute to the household income. From a multiple linear regression model, BMI was positively associated with mother's age, level of education and money spent on food, but not with HIV infection, after adjusting for week of gestation. In multivariate analysis, height increased monotonically by categories of maternal age and level of education, and was also positively correlated with the ability to contribute to household income, the amount of money spent on food per person per day, and having a professional partner.

CONCLUSION

HIV infection is a significant risk factor for wasting among pregnant women, particularly in groups of low socioeconomic status (SES). SES indicators are strongly correlated with maternal height and with BMI during the first and second trimesters of pregnancy independently of HIV status.

SPONSORSHIP

The National Institute of Child Health and Human Development (NICHD R01 32257), and the Fogarty International Center (NIH D43 TW00004).

HIV-1 LTR subtype and perinatal transmission

Multiple subtypes of HIV-1 have been identified; however, there is little data on the relative transmissibility of viruses belonging to different subtypes. A matched case-control study addressed whether viruses with different long terminal repeat (LTR) subtypes were transmitted equally from mother to infant. The LTR subtype was determined for 45 matched cases and controls who participated in a clinical trial in Tanzania. HIV-1 subtypes A, C, and D and intersubtype recombinant sequences were identified. Exact matched logistic regression analysis showed that viruses containing subtype A or intersubtype recombinant LTRs were 3.2 and 4.8 times more likely to be transmitted from mother to infant than viruses with subtype D LTRs. Viruses containing subtype C LTRs were 6.1 times more likely to be transmitted than those with subtype D LTRs. These differences in transmission were independent of maternal CD4 at enrollment. Thus, it appears that HIV-1 subtype may be associated with differing rates of perinatal transmission in Tanzania.

Predictors of intrauterine and intrapartum transmission of HIV-1 among Tanzanian women

OBJECTIVE

To examine predictors of vertical transmission of HIV-1 in Dar-es-Salaam, Tanzania.

DESIGN

Observational design.

METHODS

Consenting HIV-1-infected pregnant women (n = 1078) were enrolled in a trial to examine the role of vitamin supplements. Intrauterine HIV-1 infection (HIV-positive at birth); intrapartum and early breastfeeding transmission (HIV-positive at 6 weeks among those uninfected at birth) were defined using the PCR.

RESULTS

Of 734 infants who had a specimen taken at birth, 62 were HIV positive [8.4%; 95% confidence interval (CI),6.4--10.5%], whereas 59 infants were positive among 367 infants who were uninfected at birth and were retested at 6 weeks (16.1%; 95%CI, 12.3--19.8%). In multivariate analyses, maternal CD4 cell count, viral load, and clinical stage were significant predictors of both definitions of transmission. Viral load of 50 000 copies/ml or more at delivery was associated with a 4.21-fold increase in risk of intrapartum and early breastfeeding transmission (95%CI, 1.59--11.13;P = 0.004). Babies who were HIV negative at birth and born before 34 weeks of gestation were 2.19 times more likely to become infected during intrapartum and early breastfeeding periods compared with those born after 37 weeks (95%CI, 1.19--4.04; P = 0.01). Gonorrhea at baseline was related to intrauterine transmission [multivariate risk ratio (RR), 5.50; 95%CI, 2.04--14.81; P < 0.001] but not intrapartum and early breastfeeding transmission. Signs of lower genital infections at or after enrollment were also associated with transmission.

CONCLUSIONS

Reducing prematurity, rate of HIV disease progression, and maternal viral load at or after delivery could help to reduce vertical transmission. Treatment of sexually transmitted infections at onset of prenatal care, about 20 weeks on average, was inadequate for prevention of transmission. Whether sustained clearance of lower genital tract infections result in reduced transmission remains to be determined.

A new human immunodeficiency virus type 1 circulating recombinant form from Tanzania

It is becoming increasingly important to identify and to study human immunodeficiency virus type 1 (HIV-1) circulating recombinant forms (CRFs) with evidence of epidemic spread, since mosaic strains arise frequently, especially in populations where multiple subtypes cocirculate. We describe the almost complete nucleotide sequence of 3 subtype C and D recombinant viruses, selected from a pool of 13 D(gag)-D/C/D(env) perinatally infected infants from Dar es Salaam, Tanzania. All three genomes had cross-over points with approximately the same genomic localization. The subtype C-like sequences were located within pol, vif, vpr, vpu, the first exons of rev and tat, V3, and the U3-R regions of the LTR. Phylogenetic analyses of the full-length genomic sequences from these viruses showed the formation of a distinct subcluster on the HIV-1 subtype D branch. The pattern of recombination of genomes belonging to this new CRF, named CRF10_CD, might have resulted from independent recombination events occurring at high frequency or from a single source that originated earlier in this population. Future surveys will be needed to determine the potential of this CRF for epidemic spread.

Differences in perinatal transmission among human immunodeficiency virus type 1 genotypes

OBJECTIVE

To determine whether genotypes from human immunodeficiency virus type 1 (HIV-1) subtypes A, C, or D or intersubtype recombinants have the same probability of being transmitted from mother to child.

METHODS

We determined the HIV-1 genetic subtype and maternal risk factors of 51 matched transmitting and nontransmitting mothers from Tanzania. The HIV-1 gag (p24-p7) and env (C2-C5) nucleotide sequences were used for genotype classification, and matched logistic regression analysis was used to assess differences among genotypes.

RESULTS

Mothers infected with HIV-1 subtype A (odds ratio, 3.8; 95% CI, 0.8-24.7%), HIV-1 subtype C (odds ratio, 5.1; 95% CI, 1.3-30.8%), or HIV-1 intersubtype recombinant viruses (odds ratio, 5.3; 95% CI, 1.2-33.4%) were more likely to transmit HIV-1 to their infants than mothers infected with HIV-1 subtype D. Lower CD4 cell counts at enrollment were associated with transmission, but CD4 cell counts within each genotype did not explain differences in transmission among HIV-1 genotypes.

CONCLUSION

We have shown that HIV-1 genotypes might be associated with differential risk for vertical transmission. These findings provide the first evidence that HIV-1 genetic subtypes may play a role in rates of vertical transmission in an African setting.

Diversity of the HIV-1 long terminal repeat following mother-to-child transmission

A study of the human immunodeficiency virus Type 1 (HIV-1) 5' long terminal repeat (LTR) was performed to determine the extent of variation found within the LTR from 19 mother-infant pairs in Tanzania and to assess whether the LTR is useful in distinguishing maternal sequences that were transmitted to infants. HIV-1 subtypes A, C, and D as well as intersubtype recombinant LTR sequences were detected in mothers and infants. The LTR subtype was 100% concordant between mothers and their infants. Diversity calculations showed a significant reduction in LTR variation in infants compared to their mothers. However, the overall magnitude of LTR variation was less than that found in the env gene from the same individuals. These data suggest a selective constraint active upon the 5' long terminal repeat that is distinct from immune selective pressure(s) directed against HIV-1 structural genes. Detection of maternal LTR variants that were transmitted to infants may yield important information concerning nonstructural determinants of HIV-1 transmission from mother to infant.

Randomized trial of vitamin supplements in relation to vertical transmission of HIV-1 in Tanzania

BACKGROUND

Observational studies suggest that poor nutritional status among HIV-infected pregnant women is associated with a higher risk of vertical transmission of HIV.

METHODS

We randomized 1083 pregnant women infected with HIV-1 in a double-blind, placebo-controlled trial to examine the effects of supplements of vitamin A and/or multivitamins (excluding vitamin A) using a 2-x-2 factorial design. We report the effects of the supplements on HIV infection defined using polymerase chain reaction (PCR), or death up to 6 weeks postpartum.

RESULTS

Of babies in the multivitamin arm 38, (10.1%) were HIV-positive at birth compared with 24 (6.6%) in the no-multivitamin arm (relative risk [RR] = 1.54; 95% CI, 0.94-2.51; p = .08). Of babies born to mothers in the vitamin A arm, 38 (10.0%) were HIV-positive at birth compared with 24 (6.7%) in the no-vitamin A arm (RR, 1.49; 95% CI, 0.91-2.43; p = 0.11). Neither multivitamins nor vitamin A had an effect on HIV status at 6 weeks among those who were HIV-negative at birth (RR = 1.04; 95% CI, 0.65-1.66; p = 0.88) and (RR = 1.30; 95% CI, 0.80-2.09; p = .29, respectively). Similarly, neither supplement was associated with being either HIV-infected or dead at birth (RR, 0.98; 95% CI, 0.76-1.27; p = .89 and RR, 1.01; 95% CI, 0.78-1.31; p = .95, respectively. A beneficial effect of multivitamins on birth weight was limited to babies who were HIV-negative at birth; babies in the multivitamin arm weighed +94 g more compared with those in the no-multivitamin arm (p = .02). Among babies who were HIV-positive at birth, the corresponding difference was -31 g (p = .82).

CONCLUSIONS

Vitamin A and multivitamins did not affect the risk of vertical transmission of HIV in utero nor during the intrapartum and early breastfeeding periods. Multivitamins resulted in a significant improvement in birth weight of babies who were HIV-negative at birth but had no effect among those who were HIV-positive. The effect of vitamin supplements on HIV transmission through breastfeeding and on clinical progression of HIV disease is yet to be ascertained.

Emerging recombinant human immunodeficiency viruses: uneven representation of the envelope V3 region

OBJECTIVE

To determine whether the envelope V3 region from HIV-1 subtypes A, C or D had the same probability of being present in intersubtype recombinant genomes.

MATERIALS AND METHODS

The envelope C2-C5 and the gag p24-p7 regions from one hundred infants infected perinatally in Tanzania were compared using phylogenetic and recombination analysis. Exact binomial and Fisher's exact tests were used to assess if various genomic regions were more likely to be overrepresented in intersubtype recombinants.

RESULTS

Of one hundred HIV-1 positive infants analyzed, twenty-two (22%) showed exclusively subtype A sequence in gag and env. Subtype C accounted for twenty-two infants (22%) whereas nineteen infants (19%) were infected by HIV-1 subtype D. Intersubtype recombinant genomes accounted for thirty-seven infections (37%). The V3 region from subtype A was found in all fifteen A-D recombinants (P = 0.00003) and the V3 region from subtype C was found in all twelve C-D recombinants (P = 0.0002). Conversely, subtype D gag sequences were preferentially represented in the gag of A-D recombinants (P = 0.0003) as well as C-D recombinants (P = 0.002). In A-D recombinants, the V3 region of subtype A was generally surrounded by subtype A C3-C5 sequences. In contrast, the V3 region from subtype C was surrounded by subtype D C3-C5 sequences in C-D recombinants. Significant differences were not found in the number of subtype A or subtype C sequences in A-C recombinants.

CONCLUSION

We have shown that several recombinant HIV-1 viruses have been generated and efficiently transmitted to infants in Tanzania. The recombination patterns showed that the V3 region of subtypes A or C was always selected in A-D and C-D recombinants. This selection suggests that the fitness of subtype D-V3 in perinatal transmission may be reduced with respect to V3 from subtype A and/or subtype C. The elevated number of recombinants transmitted perinatally suggests that co-infection or super-infection by two HIV-1 subtypes is not uncommon in this population.