Zinc and multivitamin supplementation have contrasting effects on infant iron status: a randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

Zinc supplementation adversely affects iron status in animal and adult human studies but few, trials have included young infants.

OBJECTIVE

To determine the effects of zinc and multivitamin supplementation on infant hematologic and iron status.

METHODS

In a double-blind RCT, Tanzanian infants were randomized to daily, oral zinc (Zn), multivitamins (MV), Zn and MV, or placebo treatment arms at age 6 wk. Hemoglobin concentration (Hb) and red blood cell indices were measured at baseline and at 6, 12, and 18 mo of age. Plasma samples from 589 infants were examined for iron deficiency (ID) at 6 mo.

RESULTS

In logistic regression models, Zn treatment was associated with greater odds of ID (OR 1.8 [95% CI 1.0–3.3]), and MV treatment was associated with lower odds (OR 0.49 [95% CI 0.3–0.9]). In Cox models, MV were associated with a 28% reduction in risk of severe anemia (HR=0.72 [95% Cl 0.56–0.94]) and a 26% reduction in risk of severe microcytic anemia (HR=0.74 [0.56–0.96]) through 18 months. No effects of Zn on risk of anemia were seen. Infants treated with MV alone had higher mean Hb (9.9 g/dL [95% CI 9.7–10.1]) than those given placebo (9.6 g/dL [9.4–9.8]) or Zn alone (9.6 g/dL [9.4–9.7]).

CONCLUSIONS

MV treatment improved iron status in infancy, whereas Zn worsened iron status but without an associated increase in risk for anemia. Infants in long-term zinc supplementation programs at risk for ID may benefit from screening and/or the addition of a multivitamin supplement.

Maternal exposure to carbon monoxide and fine particulate matter during pregnancy in an urban Tanzanian cohort

Low birthweight contributes to as many as 60% of all neonatal deaths; exposure during pregnancy to household air pollution has been implicated as a risk factor. Between 2011 and 2013, we measured personal exposures to carbon monoxide (CO) and fine particulate matter (PM_2.5 ) in 239 pregnant women in Dar es Salaam, Tanzania. CO and PM_2.5 exposures during pregnancy were moderately high (geometric means 2.0 ppm and 40.5 μg/m³ ); 87% of PM_2.5 measurements exceeded WHO air quality guidelines. Median and high (75th centile) CO exposures were increased for those cooking with charcoal and kerosene versus kerosene alone in quantile regression. High PM_2.5 exposures were increased with charcoal use. Outdoor cooking reduced median PM_2.5 exposures. For PM_2.5 , we observed a 0.15 kg reduction in birthweight per interquartile increase in exposure (23.0 μg/m³ ) in multivariable linear regression; this finding was of borderline statistical significance (95% confidence interval 0.30, 0.00 kg; P = 0.05). PM_2.5 was not significantly associated with birth length or head circumference nor were CO exposures associated with newborn anthropometrics. Our findings contribute to the evidence that exposure to household air pollution, and specifically fine particulate matter, may adversely affect birthweight.

The prevalence of anemia and iron deficiency is more common in breastfed infants than their mothers in Bhaktapur, Nepal

Background/Objectives:

Iron deficiency anemia is a widespread public health problem, particularly in low- and middle-income countries. Maternal iron status around and during pregnancy may influence infant iron status. We examined multiple biomarkers to determine the prevalence of iron deficiency and anemia among breastfed infants and explored its relationship with maternal and infant characteristics in Bhaktapur, Nepal.

Subjects/Methods:

In a cross-sectional survey, we randomly selected 500 mother–infant pairs from Bhaktapur municipality. Blood was analyzed for hemoglobin, ferritin, total iron-binding capacity, transferrin receptors and C-reactive protein.

Results:

The altitude-adjusted prevalence of anemia was 49% among infants 2–6-month-old (hemaglobin (Hb) <10.8 g/dl) and 72% among infants 7–12-month-old (Hb <11.3 g/dl). Iron deficiency anemia, defined as anemia and serum ferritin <20 or <12 μg/l, affected 9 and 26% of infants of these same age groups. Twenty percent of mothers had anemia (Hb <12.3 g/dl), but only one-fifth was explained by depletion of iron stores. Significant predictors of infant iron status and anemia were infant age, sex and duration of exclusive breastfeeding and maternal ferritin concentrations.

Conclusions:

Our findings suggest that iron supplementation in pregnancy is likely to have resulted in a low prevalence of postpartum anemia. The higher prevalence of anemia and iron deficiency among breastfed infants compared with their mothers suggests calls for intervention targeting newborns and infants.

Elevated alanine aminotransferase in antiretroviral-naïve HIV-infected African patients: magnitude and risk factors

BACKGROUND

Alanine aminotransferase (ALT) is commonly used to measure liver injury in resource-limited settings. Elevations in ALT are predictive of increased mortality from liver disease and may influence the choice of first-line antiretroviral therapy (ART).

METHODS

A cross-sectional analysis of the prevalence and predictors of elevated ALT (defined as >40 IU/L) was conducted. ART-naïve, HIV-infected adults with a baseline ALT measurement who were enrolled in any of the 18 HIV Care and Treatment Clinics in Dar es Salaam, Tanzania between November 2004 and December 2009 were included in the study. Median values were calculated and log-binomial regression models were used to examine predictors of elevated ALT.

RESULTS

During the study period, 41891 adults had a baseline ALT measurement performed. The prevalence of ALT >40, >120 and >200 IU/L was 13, 1 and 0.3%, respectively. In multivariate analyses, male sex, CD4 T lymphocyte count <200 cells/μL and higher World Health Organization (WHO) clinical stages were associated with a significantly higher risk of ALT >40 IU/L (all P<0.01). Hypertryglyceridaemia, hyperglycaemia and hepatitis B virus (HBV) coinfection (positive for HBV surface antigen) were significantly associated with a higher risk of elevated ALT. Pregnancy, anaemia, low-density lipoprotein cholesterol >130 mg/dL and current tuberculosis treatment were associated with a significantly reduced risk for elevated ALT.

CONCLUSIONS

In this HIV-infected, ART-naïve Tanzanian population, extreme elevations in ALT were infrequent but minor elevations were not uncommon. Antiretrovirals with potentially hepatotoxic side effects should be initiated with caution in male patients, and in patients with HBV coinfection, advanced immunosuppression and components of the metabolic syndrome.

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.

Vitamin A status of patients presenting with pulmonary tuberculosis and asymptomatic HIV-infected individuals, Dar es Salaam, Tanzania

Serum vitamin A was determined in a cross-sectional study of 100 HIV-positive and -negative tuberculosis patients and 144 blood donors. Tuberculosis patients were seen again after 2 months of treatment. Mean vitamin A was lowest among tuberculosis patients co-infected with HIV, and was lower among HIV-positive than -negative donors. Mean vitamin A rose significantly at 2 months in HIV-negative patients, and not in -positive patients. HIV infection was the strongest predictor of low vitamin A. Vitamin A deficiency is common in tuberculosis and HIV infection, particularly in those patients who are dually infected, and nutritional supplementation may be beneficial.

Validity of the Hopkins Symptom Checklist-25 amongst HIV-positive pregnant women in Tanzania

OBJECTIVE

To validate the Hopkins Symptom Checklist-25 (HSCL-25) for use as a depression screen amongst human immuno-deficiency virus (HIV) positive pregnant women.

METHOD

Amongst 903 (mean age 24.8 years) HIV-positive pregnant women, a two-phased design included measures for health-related quality of life, perceived social support, and the HSCL-25 screen for depressive (HSCL-15 subscale) and anxiety symptoms. The Structured Clinical Interview for DSM-IV (SCID) was independently administered on a stratified random subsample.

RESULTS

Internal consistency of the HSCL-25 (alpha 0.93) and HSCL-15 (alpha 0.9) was adequate, with expected findings demonstrated in discriminant validity analysis. A depression-anxiety construct explained nearly 40% of the variance. Eight individual HSCL-25 items demonstrated an area under the curve (AUC) greater than 0.6 for DSM-IV major depression and the HSCL-25 and HSCL-revised had an optimal depression cut-off score of 1.06 and 1.03 for the HSCL-15.

CONCLUSION

The HSCL-25 demonstrated utility as a screen for depression; its inability to gauge severity of symptoms in this cultural context is discussed.

Micronutrients and child health: studies in international nutrition and HIV infection

Increasing data link micronutrient deficiencies to excess childhood morbidity and mortality, and similar relationships have been noted in the study of nutrition and HIV infection. We review epidemiologic studies that have examined the relationship between micronutrient deficiencies and health outcomes in childhood and HIV infection, as well as clinical trials of micronutrient supplementation. Vitamin A supplementation among communities at risk of deficiency effectively reduces mortality and morbidity in children younger than age 5, and vitamin A may be especially effective in HIV-infected children. Vertical transmission of HIV has not to date been affected by maternal micronutrient supplementation. In children with poor dietary zinc intake and/or bioavailability, zinc supplementation reduces the incidence and severity of diarrheal diseases, as well as the occurrence of pneumonia. Vitamin A therapy has not been associated with improved growth, whereas some trials have shown that zinc supplementation is associated with greater increments in height. Further trials of micronutrient supplementation are warranted.

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.

Nutritional factors and vertical transmission of HIV-1. Epidemiology and potential mechanisms

Transmission of HIV from mothers to children may occur through the transplacental, intrapartum, or breastfeeding routes. Adequate nutritional status may reduce vertical transmission by affecting several maternal or fetal and child risk factors for transmission including enhancing systemic immune function in the mother or fetus/child; reducing the rate of clinical, immunological, or virological progression in the mother; reducing viral load or the risk of viral shedding in lower genital secretions or breast milk; reducing the risks of low birth weight or prematurity; or by maintaining the integrity of the fetus/child gastrointestinal integrity. In prospective observational studies, low plasma vitamin A levels were associated with higher risks of vertical transmission. However, findings from randomized, controlled trials suggest that supplements of vitamin A or other vitamins are unlikely to have an effect on vertical transmission during pregnancy or the intrapartum period. The effect of other nutrient supplements, such as zinc and selenium, is unknown. Similarly, whether nutrition supplements of mothers during the breastfeeding period has an effect on transmission is unknown. The potential benefits of direct supplementation of children born to HIV-infected women on transmission of HIV, as well as on the risk and severity of childhood infections and mortality, are also important to examine.

Tomato intake in relation to mortality and morbidity among Sudanese children

The intake of foods that contain high levels of antioxidants may counteract the adverse effects of oxidative stress and lead to improved immune function and reduced risk of infectious disease. We prospectively examined the relationship between the consumption of tomatoes, a rich source of antioxidants, and mortality and diarrheal and respiratory morbidity rates among 28,753 children who were 6-60 mo old and enrolled in a longitudinal study in the Sudan. Children in each household were visited every 6 mo for a maximum of four visits. At each round, mothers recalled whether a child had consumed tomatoes in the previous 24 h. Events (death or morbidity) reported at each round were prospectively allocated according to the number of days of tomato intake. Intake of tomatoes for 2 or 3 d compared with none was associated, respectively, with 48% (relative risk, 0. 53; 95% confidence interval, 0.30-0.91) and 83% (0.17; 0.04-0.72) reductions in morality rates (P: for trend = 0.002). The association between tomato use and death remained statistically significant (P: for trend = 0.004), even after further adjustment for total vitamin A intake. Tomato intake was also associated with a reduced risk of death associated with diarrhea in the week preceding death (P: for trend = 0.009) or fever (P: for trend = 0.04). Intake of tomatoes was also inversely and significantly associated with the risks of diarrheal and respiratory infections. Our data suggest that tomatoes may be beneficial for child health but also emphasize the general importance of food-based approaches to the prevention of micronutrient malnutrition and protection of the health of children in developing countries.

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.

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.

Risk factors associated with xerophthalmia in northern Sudan

The prevalence of eye signs and symptoms of vitamin A deficiency was determined among 29,615 Sudanese children between 6 and 72 mo of age, in five rural areas of Khartoum and Gezira provinces. Of all children, 2.9% were vitamin A deficient, and of these > 90% had Bitot's spots. Bivariate associations were found between xerophthalmia and the rural councils where the children lived, household wealth, consumption of vitamin A-containing foods, child sex, child age and weight-for-height Z-scores. Multivariate analysis showed that the following factors made significant independent contributions to the risk of xerophthalmia: living in remote and arid regions, male gender, age, poverty of the household, and prevalence of diarrhea. On the other hand, less xerophthalmia was observed among children who during the 24 h preceding the survey had consumed dairy products or non-leafy vegetables containing vitamin A. Intervention programs aimed at increasing household income and promoting consumption of foods containing vitamin A should contribute to the reduction of vitamin A deficiency among Sudanese children.