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R Nduati

Publications and source records attributed to R Nduati.

18 recordsLinked to original sources
PubMed2001

Morbidity and mortality in breastfed and formula-fed infants of HIV-1-infected women: A randomized clinical trial.

CONTEXT: Breastfeeding among women infected with human immunodeficiency virus type 1 (HIV-1) is associated with substantial risk of HIV-1 transmission, but little is known about the morbidity risks associated with formula feeding in infants of HIV-1-infected women in resource-poor settings. OBJECTIVE: To compare morbidity, nutritional status, mortality adjusted for HIV-1 status, and cause of death among formula-fed and breastfed infants of HIV-1-infected women. DESIGN: Randomized clinical trial conducted between 1992 and 1998. SETTING: Four antenatal clinics in Nairobi, Kenya. PARTICIPANTS: Of 401 live-born, singleton, or first-born twin infants of randomized HIV-1-seropositive mothers, 371 were included in the analysis of morbidity and mortality. INTERVENTIONS: Mothers were randomly assigned either to use formula (n = 186) or to breastfeed (n = 185) their infants. MAIN OUTCOME MEASURES: Mortality rates, adjusted for HIV-1 infection status; morbidity; and nutritional status during the first 2 years of life. RESULTS: Two-year estimated mortality rates among infants were similar in the formula-feeding and breastfeeding arms (20.0% vs 24.4%; hazard ratio [HR], 0.8; 95% confidence interval [CI], 0.5-1.3), even after adjusting for HIV-1 infection status (HR, 1.1; 95% CI, 0.7-1.7). Infection with HIV-1 was associated with a 9.0-fold increased mortality risk (95% CI, 5.3-15.3). The incidence of diarrhea during the 2 years of follow-up was similar in formula and breastfeeding arms (155 vs 149 per 100 person-years, respectively). The incidence of pneumonia was identical in the 2 groups (62 per 100 person-years), and there were no significant differences in incidence of other recorded illnesses. Infants in the breastfeeding arm tended to have better nutritional status, significantly so during the first 6 months of life. CONCLUSIONS: In this randomized clinical trial, infants assigned to be formula fed or breastfed had similar mortality rates and incidence of diarrhea and pneumonia during the first 2 years of life. However, HIV-1-free survival at 2 years was significantly higher in the formula arm. With appropriate education and access to clean water, formula feeding can be a safe alternative to breastfeeding for infants of HIV-1-infected mothers in a resource-poor setting.

Adult↗
PubMed2001

CCR5 promoter polymorphisms in a Kenyan perinatal human immunodeficiency virus type 1 cohort: association with increased 2-year maternal mortality.

The CCR5 chemokine receptor acts as a coreceptor with CD4 to permit infection by primary macrophage-tropic human immunodeficiency virus type 1 (HIV-1) strains. The CCR5Delta32 mutation, which is associated with resistance to infection in homozygous individuals and delayed disease progression in heterozygous individuals, is rare in Africa, where the HIV-1 epidemic is growing rapidly. Several polymorphisms in the promoter region of CCR5 have been identified, the clinical and functional relevance of which remain poorly defined. We evaluated the effect of 4 CCR5 promoter mutations on systemic and mucosal HIV-1 replication, disease progression, and perinatal transmission in a cohort of 276 HIV-1-seropositive women in Nairobi, Kenya. Mutations at positions 59353, 59402, and 59029 were not associated with effects on mortality, virus load, genital shedding, or transmission in this cohort. However, women with the 59356 C/T genotype had a 3.1-fold increased risk of death during the 2-year follow-up period (95% confidence interval [CI], 1.0-9.5) and a significant increase in vaginal shedding of HIV-1-infected cells (odds ratio, 2.1; 95% CI, 1.0-4.3), compared with women with the 59356 C/C genotype.

Adult↗
PubMed2001

Effect of breastfeeding on mortality among HIV-1 infected women: a randomised trial.

BACKGROUND: We have completed a randomised clinical trial of breastfeeding and formula feeding to identify the frequency of breastmilk transmission of HIV-1 to infants. However, we also analysed data from this trial to examine the effect of breastfeeding on maternal death rates during 2 years after delivery. We report our findings from this secondary analysis. METHODS: Pregnant women attending four Nairobi city council clinics were offered HIVtests. At about 32 weeks' gestation, 425 HIV-1 seropositive women were randomly allocated to either breastfeed or formula feed their infants. After delivery, mother-infant pairs were followed up monthly during the first year and quarterly during the second year until death, or 2 years after delivery, or end of study. FINDINGS: Mortality among mothers was higher in the breastfeeding group than in the formula group (18 vs 6 deaths, log rank test, p=0.009). The cumulative probability of maternal death at 24 months after delivery was 10.5% in the breastfeeding group and 3.8% in the formula group (p=0.02). The relative risk of death for breastfeeding mothers versus formula feeding mothers was 3.2 (95% CI 1.3-8.1, p=0.01). The attributable risk of maternal death due to breastfeeding was 69%. There was an association between maternal death and subsequent infant death, even after infant HIV-1 infection status was controlled for (relative risk 7.9, 95% CI 3.3-18.6, p<0.001). INTERPRETATION: Our findings suggest that breastfeeding by HIV-1 infected women might result in adverse outcomes for both mother and infant.

Adult↗
PubMed2001

Comparison of techniques for HIV-1 RNA detection and quantitation in cervicovaginal secretions.

PRINCIPLES: HIV-1 in female genital secretions has been measured using swabs, Sno Strips (Akorn, Inc., Buffalo Grove, IL), and cervicovaginal lavage (CVL), but little is known regarding the comparability of these collection techniques. METHODS: We compared HIV-1 RNA detection and quantity in specimens obtained from HIV-1-seropositive women in Kenya using three sample collection techniques and three storage techniques and evaluated reproducibility in samples collected 5 days apart. Specimens were stored in no medium, freezing medium, or TRI Reagent (Molecular Research Center, Cincinnati, OH) for 2 to 15 months. RESULTS: HIV-1 RNA assays were conducted on 640 specimens from 20 antiretroviral naive women. Storage in TRI Reagent significantly enhanced detection of genital HIV-1 and yielded significantly higher mean log10 RNA levels than specimens collected in either no or freezing medium. The prevalence of HIV-1 RNA detection in TRI Reagent ranged from 50% to 80% depending on collection method and was highest in cervical swabs. Mean log10 HIV-1 RNA levels were 3.1 log10 copies/cervical swab, 2.6 log10 copies/cervical Sno Strip, 2.5 log10 copies/vaginal swab, 2.4 log10 copies/vaginal Sno Strip, 2.9 log10 copies/ml for cervicovaginal lavage (CVL) cell pellet, and 2.1 log10 copies/ml in CVL supernatant. Comparing specimens from days 1 and 6, there was significant concordance of HIV-1 RNA detection and correlation of HIV-1 RNA levels for cervical swabs, vaginal swabs, vaginal Sno Strips, and CVL cell pellets (kappa, 0.5-0.9; r, 0.5-0.9), but not for cervical Sno Strips or CVL supernatants. CONCLUSIONS: Cervical or vaginal swab, vaginal Sno Strip, and CVL collection led to reproducible measurement of genital HIV-1 RNA, despite storage for several months and international transport. Collection using swabs was simpler than Sno Strips or cervicovaginal lavage, and yielded the highest prevalence of HIV-1 RNA detection and reproducibility.

Cervix Uteri↗
PubMed2000

Effect of breastfeeding and formula feeding on transmission of HIV-1: a randomized clinical trial.

CONTEXT: Transmission of human immunodeficiency virus type 1 (HIV-1) is known to occur through breastfeeding, but the magnitude of risk has not been precisely defined. Whether breast milk HIV-1 transmission risk exceeds the potential risk of formula-associated diarrheal mortality in developing countries is unknown. OBJECTIVES: To determine the frequency of breast milk transmission of HIV-1 and to compare mortality rates and HIV-1-free survival in breastfed and formula-fed infants. DESIGN AND SETTING: Randomized clinical trial conducted from November 1992 to July 1998 in antenatal clinics in Nairobi, Kenya, with a median follow-up period of 24 months. PARTICIPANTS: Of 425 HIV-1-seropositive, antiretroviral-naive pregnant women enrolled, 401 mother-infant pairs were included in the analysis of trial end points. INTERVENTIONS: Mother-infant pairs were randomized to breastfeeding (n = 212) vs formula feeding arms (n = 213). MAIN OUTCOME MEASURES: Infant HIV-1 infection and death during the first 2 years of life, compared between the 2 intervention groups. RESULTS: Compliance with the assigned feeding modality was 96% in the breastfeeding arm and 70% in the formula arm (P<.001). Median duration of breastfeeding was 17 months. Of the 401 infants included in the analysis, 94% were followed up to HIV-1 infection or mortality end points: 83% for the HIV-1 infection end point and 93% to the mortality end point. The cumulative probability of HIV-1 infection at 24 months was 36.7% (95% confidence interval [CI], 29.4%-44.0%) in the breastfeeding arm and 20.5% (95% CI, 14.0%-27.0%) in the formula arm (P = .001). The estimated rate of breast milk transmission was 16.2% (95% CI, 6.5%-25.9%). Forty-four percent of HIV-1 infection in the breastfeeding arm was attributable to breast milk. Most breast milk transmission occurred early, with 75% of the risk difference between the 2 arms occurring by 6 months, although transmission continued throughout the duration of exposure. The 2-year mortality rates in both arms were similar (breastfeeding arm, 24.4% [95% CI, 18.2%-30.7%] vs formula feeding arm, 20.0% [95% CI, 14.4%-25.6%]; P = .30). The rate of HIV-1-free survival at 2 years was significantly lower in the breastfeeding arm than in the formula feeding arm (58.0% vs 70.0%, respectively; P = .02). CONCLUSIONS: The frequency of breast milk transmission of HIV-1 was 16.2% in this randomized clinical trial, and the majority of infections occurred early during breastfeeding. The use of breast milk substitutes prevented 44% of infant infections and was associated with significantly improved HIV-1-free survival.

AIDS Serodiagnosis↗
PubMed2000

Prevention of mother-to-child transmission of HIV in developing countries: recommendations for practice. The Ghent International Working Group on Mother-To-Child Transmission of HIV.

OBJECTIVES: Different approaches to prevent mother-to-child transmission of HIV are being evaluated in developing countries. The first trials using a short regimen of zidovudine have been successful in Thailand, Côte d'Ivoire and Burkina Faso. International and local strategies are now being considered. The Ghent International Working Group on Mother-to-Child Transmission of HIV developed public health policy options to integrate these interventions into basic and maternal and child health (MCH) services. METHODS: The following tasks were undertaken: a critical review of randomized trials; an international pooled analysis of late postnatal transmission of HIV through breastfeeding; a review of the cost-effectiveness and cost-benefit of antiretroviral prophylaxis; a feasibility assessment of preventive strategies, including a postal survey on HIV voluntary counselling and testing (VCT) of pregnant women; the identification of requirements and research priorities for prenatal, obstetric and paediatric care. These projects provided the background for a three-day workshop in Ghent, Belgium, in November 1997. Conclusions were further refined, based on 1998 research findings. RESULTS: A summary of relevant evidence and ten public health recommendations are reported. VCT for pregnant women, a short regimen of zidovudine together with alternatives to breastfeeding currently represent the best option to reduce vertical transmission in most developing countries. The primary goal of the integrated package supporting these interventions is to alleviate overall maternal and infant morbidity and mortality. CONCLUSION: Prevention of mother-to-child transmission of HIV should now be considered for integration into basic health and MCH services of selected countries, with the involvement of governments and donor agencies.

Anti-HIV Agents↗
PubMed2000

Evaluation of performance of the Gen-Probe human immunodeficiency virus type 1 viral load assay using primary subtype A, C, and D isolates from Kenya.

Accurate and sensitive quantification of human immunodeficiency virus type 1 (HIV-1) RNA has been invaluable as a marker for disease prognosis and for clinical monitoring of HIV-1 disease. The first generation of commercially available HIV-1 RNA tests were optimized to detect the predominant HIV-1 subtype found in North America and Europe, subtype B. However, these tests are frequently suboptimal in detecting HIV-1 genetic forms or subtypes found in other parts of the world. The goal of the present study was to evaluate the performance of a new viral load assay with non-subtype B viruses. A transcription-mediated amplification method for detection and quantitation of diverse HIV-1 subtypes, called the Gen-Probe HIV-1 viral load assay, is under development. In this study we examined the performance of the Gen-Probe HIV-1 viral load assay relative to that of the commonly used commercial HIV-1 RNA assays using a panel of primary isolates from Kenya. For comparison, we included several subtype B cloned viruses, and we quantified each virus using an in-house quantitative-competitive reverse transcriptase PCR (QC-RT-PCR) method and gag(p24) antigen capture. The Gen-Probe HIV-1 viral load assay and a version of the Roche AMPLICOR HIV-1 MONITOR test (version 1.5) that was designed to detect a broader range of subtypes were both sensitive for the quantification of Kenyan primary isolates, which represented subtype A, C, and D viruses. The Gen-Probe HIV-1 viral load assay was more sensitive for the majority of viruses than the Roche AMPLICOR HIV-1 MONITOR test version 1.0, the Bayer Quantiplex HIV RNA 3.0 assay, or a QC-RT-PCR method in use in our laboratory, suggesting that it provides a useful method for quantifying HIV-1 RNAs from diverse parts of the world, including Africa.

Adult↗
PubMed2000

Maternal SDF1 3'A polymorphism is associated with increased perinatal human immunodeficiency virus type 1 transmission.

Genetic polymorphisms in chemokine and chemokine receptor genes influence susceptibility to human immunodeficiency virus type 1 (HIV-1) infection and disease progression, but little is known regarding the association between these allelic variations and the ability of the host to transmit virus. In this study, we show that the maternal heterozygous SDF1 genotype (SDF1 3'A/wt) is associated with perinatal transmission of HIV-1 (risk ratio [RR], 1.8; 95% confidence interval [CI], 1.0 to 3.3) and particularly postnatal breastmilk transmission (RR, 3.1; 95% CI, 1.1 to 8.6). In contrast, the infant SDF1 genotype had no effect on mother-to-infant transmission. These data suggest that SDF1, which is a ligand for the T-tropic HIV-1 coreceptor CXCR4, may affect the ability of a mother to transmit the virus to her infant. This suggests that a genetic polymorphism in a gene encoding a chemokine receptor ligand may be associated with increased infectivity of the index case and highlights the importance of considering transmission as well as clinical outcome in designing chemokine-based therapies for HIV-1.

3' Untranslated Regions↗
PubMed1999

Studies of human immunodeficiency virus type 1 mucosal viral shedding and transmission in Kenya.

If human immunodeficiency virus type 1 (HIV-1) vaccines are to be highly effective, it is essential to understand the virologic factors that contribute to HIV-1 transmission. It is likely that transmission is determined, in part, by the genotype or phenotype (or both) of infectious virus present in the index case, which in turn will influence the quantity of virus that may be exchanged during sexual contact. Transmission may also depend on the fitness of the virus for replication in the exposed individual, which may be influenced by whether a virus encounters a target cell that is susceptible to infection by that specific variant. Of interest, our data suggest that the complexity of the virus that is transmitted may be different in female and male sexual exposures.

Adult↗
PubMed1999

Rapid method for screening dried blood samples on filter paper for human immunodeficiency virus type 1 DNA.

PCR is a highly sensitive method for the detection of human immunodeficiency virus type 1 (HIV-1) nucleic acids in blood mononuclear cells and plasma. However, blood separation techniques require extensive laboratory support systems and are difficult when a limited volume of blood is available, which is often the case for infants. The use of blood samples stored on filter paper has many advantages for the detection of perinatal HIV-1 infection, but current methods require extraction and purification of target DNA prior to PCR amplification. We report a highly sensitive and rapid method for the extraction and detection of HIV-1 DNA in infant blood samples stored on filter papers. Because this rapid protocol does not involve steps for the removal of potential inhibitors of the PCR, the highest sensitivity is achieved by testing the filter paper lysate in quadruplicate. Assays for HIV-1 DNA were done by using nested PCR techniques that amplify HIV-1 gag DNA from blood spot samples on filter paper and from corresponding viably frozen mononuclear cells separated from venous blood samples obtained from 111 infants born to HIV-1-seropositive mothers. PCR results with blood from filter papers showed 100% specificity (95% confidence internal [CI] 93.1 to 100%) and 96% (95% CI, 88.65 to 98.9%) and 88% (95% CI, 79.2 to 94.5%) sensitivity (for quadruplicate and duplicate tests, respectively) compared to PCR results with blood mononuclear cells. Moreover, this method could detect HIV-1 sequences of multiple subtypes.

Blood↗
PubMed1999

Effects of passive smoking and breastfeeding on childhood bronchial asthma.

OBJECTIVE: To evaluate the effect of passive smoking and breastfeeding on the severity and age of onset of bronchial asthma. DESIGN: Cross-sectional study. SETTING: Paediatric observation ward and paediatric chest clinic, Kenyatta National Hospital. PATIENTS: Children aged between one and 120 months. RESULTS: More than fifty per cent of the children had their first wheeze at less than 12 months of age and 68% were categorised as having moderate to severe asthma. Passive smoking was positively significantly associated with early onset of wheezing (chi 2 = 6.22, p = 0.012, Odds ratio = 2.44, 95% CI 1.2,5.0), and also, at a non significant level, to severity of asthma (chi 2 = 2.8, p = 0.09, Odds ratio = 2.1, 95% CI 0.9,4.7). On the other hand, exclusive breastfeeding was significantly negatively associated with severity of bronchial asthma (chi 2 = 4.02, p = 0.045, Odds ratio = 0.4, 95% CI 0.14,0.98), but did not seen to have effect on age of onset of the disease (chi 2 = 0.0006, p = 0.94, Odds ratio = 0.9, 95% CI 0.4,2.2). CONCLUSION: Passive smoking is associated with early onset of asthma and possibly with development of severe asthma while exclusive breastfeeding is protective against development of severe asthma but does not seem to affect the age of onset of this disease.

Age of Onset↗
PubMed1998

Cell-free human immunodeficiency virus type 1 in breast milk.

Breast-feeding may be an important route of human immunodeficiency virus type 1 (HIV-1) vertical transmission in settings where it is routinely practiced. To define the prevalence and quantity of HIV-1 in cell-free breast milk, samples from HIV-1-seropositive women were analyzed by quantitative competitive reverse transcription-polymerase chain reaction (QC-RT-PCR). HIV-1 RNA was detected in 29 (39%) of 75 specimens tested. Of these 29 specimens, 16 (55%) had levels that were near the detection limit of the assay (240 copies/mL), while 6 (21%) had >900 copies/mL. The maximum concentration of HIV-1 RNA detected was 8100 copies/mL. The prevalence of cell-free HIV-1 was higher in mature milk (47%) than in colostrum (27%, P = 0.1). Because mature milk is consumed in large quantities, these data suggest that cell-free HIV-1 in breast milk may contribute to vertical transmission of HIV-1.

Adolescent↗