Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Infect Dis ; 2024 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-38462671

RESUMEN

BACKGROUND: The association between low-frequency HIV-1 drug resistance mutations (DRMs) and treatment failure (TF) is controversial. We explore this association using NGS methods that accurately sample low-frequency DRMs. METHODS: We enrolled women with HIV-1 in Malawi who were either ART naïve (A), had ART failure (B), or had discontinued ART (C). At entry, A and C began an NNRTI-based regimen and B started a PI-based regimen. We used Primer ID MiSeq to identify regimen-relevant DRMs in entry and TF plasma samples, and a Cox proportional hazards model to calculate hazard ratios (HRs) for entry DRMs. Low-frequency DRMs were defined as ≤ 20%. RESULTS: We sequenced 360 participants. Cohort B and C participants were more likely to have TF than Cohort A participants. The presence of K103N at entry significantly increased TF risk among A and C participants at both high and low frequency, with HR of 3.12 [1.58-6.18, 95% CI] and 2.38 [1.00-5.67, 95% CI] respectively. At TF, 45% of participants showed selection of DRMs while in the remaining participants there was an apparent lack of selective pressure from ART. CONCLUSIONS: Using accurate NGS for DRM detection may benefit an additional 10% of the patients by identifying low-frequency K103N mutations.

2.
J Infect Dis ; 225(2): 257-268, 2022 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-34244739

RESUMEN

BACKGROUND: Plasmodium falciparum malaria dominates throughout sub-Saharan Africa, but the prevalence of Plasmodium malariae, Plasmodium ovale spp., and Plasmodium vivax increasingly contribute to infection in countries that control malaria using P. falciparum-specific diagnostic and treatment strategies. METHODS: We performed quantitative polymerase chain reaction (qPCR) on 2987 dried blood spots from the 2015-2016 Malawi Demographic and Health Survey to identify presence and distribution of nonfalciparum infection. Bivariate models were used to determine species-specific associations with demographic and environmental risk factors. RESULTS: Nonfalciparum infections had broad spatial distributions. Weighted prevalence was 0.025 (SE, 0.004) for P. malariae, 0.097 (SE, 0.008) for P. ovale spp., and 0.001 (SE, 0.0005) for P. vivax. Most infections (85.6%) had low-density parasitemias ≤ 10 parasites/µL, and 66.7% of P. malariae, 34.6% of P. ovale spp., and 40.0% of P. vivax infections were coinfected with P. falciparum. Risk factors for P. malariae were like those known for P. falciparum; however, there were few risk factors recognized for P. ovale spp. and P. vivax, perhaps due to the potential for relapsing episodes. CONCLUSIONS: The prevalence of any nonfalciparum infection was 11.7%, with infections distributed across Malawi. Continued monitoring of Plasmodium spp. becomes critical as nonfalciparum infections become important sources of ongoing transmission.


Asunto(s)
Malaria/epidemiología , Plasmodium malariae/aislamiento & purificación , Plasmodium ovale/aislamiento & purificación , Plasmodium vivax/aislamiento & purificación , Adolescente , Adulto , Femenino , Humanos , Malaria/diagnóstico , Malaria Vivax/epidemiología , Malaui/epidemiología , Masculino , Plasmodium malariae/genética , Plasmodium ovale/genética , Plasmodium vivax/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Adulto Joven
3.
Clin Infect Dis ; 73(7): e2000-e2004, 2021 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-33033831

RESUMEN

BACKGROUND: Prior to the widespread availability of antiretroviral therapy (ART), men living with human immunodeficiency virus (HIV) with urethritis had increased concentrations of HIV in semen. This study aims to better evaluate HIV shedding in men with urethritis receiving ART, and its implications for the cure of HIV. METHODS: Men living with HIV with urethritis taking ART ≥12 weeks were enrolled at a sexually transmitted infections clinic in Lilongwe, Malawi. Study follow-up included visits at 1, 2, 4, 8, 12, 24, 36, and 48 weeks after urethritis diagnosis and treatment. Matched blood and semen samples were collected at all visits, and all additional episodes of urethritis were followed with extra visits 1, 2, and 4 weeks after treatment. RESULTS: There were 111 men enrolled in the study between January 2017-March 2019, and 77 (69%) were suppressed in the blood (<400 copies/mL). Among the 77 men, 87 episodes of urethritis were evaluated during follow-up. Of the 87 episodes, 15 episodes (17%) had instances of seminal viral shedding ≥400 copies/mL despite viral suppression in the blood. During nonurethritis follow-up, ≤6% of men at each visit had a viral load ≥400 copies/mL in the semen while maintaining viral suppression in the blood. CONCLUSIONS: An HIV cure requires the elimination of HIV from every body compartment, but available ART does not currently accomplish this. Our study highlights the male genital tract as a local source of HIV that can be reversibly activated. A better understanding of this phenomenon is important to advance the HIV cure field.


Asunto(s)
Infecciones por VIH , VIH-1 , Uretritis , Infecciones por VIH/tratamiento farmacológico , VIH-1/genética , Humanos , Masculino , ARN Viral , Semen , Uretritis/tratamiento farmacológico , Carga Viral , Esparcimiento de Virus
4.
J Virol ; 94(12)2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32269129

RESUMEN

Concurrent sexually transmitted infections (STI) can increase the probability of HIV-1 transmission primarily by increasing the viral load present in semen. In this study, we explored the relationship of HIV-1 in blood and seminal plasma in the presence and absence of urethritis and after treatment of the concurrent STI. Primer ID deep sequencing of the V1/V3 region of the HIV-1 env gene was done for paired blood and semen samples from antiretroviral therapy (ART)-naive men living in Malawi with (n = 19) and without (n = 5) STI-associated urethritis; for a subset of samples, full-length env genes were generated for sequence analysis and to test entry phenotype. Cytokine concentrations in the blood and semen were also measured, and a reduction in the levels of proinflammatory cytokines was observed following STI treatment. We observed no difference in the prevalence of diverse compartmentalized semen-derived lineages in men with or without STI-associated urethritis, and these viral populations were largely stable during STI treatment. Clonal amplification of one or a few viral sequences accounted for nearly 50% of the viral population, indicating a recent bottleneck followed by limited viral replication. We conclude that the male genital tract is a site where virus can be brought in from the blood, where localized sustained replication can occur, and where specific genotypes can be amplified, perhaps initially by cellular proliferation but further by limited viral replication.IMPORTANCE HIV-1 infection is a sexually transmitted infection that coexists with other STI. Here, we examined the impact of a concurrent STI resulting in urethritis on the HIV-1 population within the male genital tract. We found that viral populations remain largely stable even with treatment of the STI. These results show that viral populations within the male genital tract are defined by factors beyond transient inflammation associated with a concurrent STI.


Asunto(s)
Infecciones por VIH/virología , VIH-1/genética , Semen/virología , Enfermedades de Transmisión Sexual/virología , Uretritis/virología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética , Adulto , Secuencia de Bases , Recuento de Linfocito CD4 , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/virología , Estudios de Cohortes , Citocinas/genética , Citocinas/inmunología , Infecciones por VIH/epidemiología , Infecciones por VIH/inmunología , Infecciones por VIH/transmisión , VIH-1/clasificación , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Malaui/epidemiología , Masculino , Persona de Mediana Edad , Filogenia , Enfermedades de Transmisión Sexual/epidemiología , Enfermedades de Transmisión Sexual/inmunología , Enfermedades de Transmisión Sexual/transmisión , Uretritis/epidemiología , Replicación Viral , Productos del Gen env del Virus de la Inmunodeficiencia Humana/sangre , Productos del Gen env del Virus de la Inmunodeficiencia Humana/clasificación
5.
BMC Public Health ; 20(1): 910, 2020 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-32532234

RESUMEN

BACKGROUND: RTS,S/AS01 is the first vaccine against malaria to undergo pilot implementation, beginning in 2019 and vaccinating 360,000 children per year in Malawi, Ghana, and Kenya. The four-dose vaccine is given as a primary three-dose series with a fourth dose given approximately 18 months later. The efficacy of RTS,S/AS01 was variable among the 11 sites participating in the 2009-2014 phase III trial (MALARIA-055, NCT00866619), possibly due to differences in transmission intensity. However, a within-site examination of environmental factors related to transmission intensity and their impact on vaccine efficacy has yet to be conducted. METHODS: We implemented the phase III RTS,S/AS01 trial at the Malawi site, which enrolled 1578 infants (6-12 weeks) and children (5-17 months) living in the Lilongwe District in Central Malawi and followed them for 3 years between 2009 and 2014. A global positioning system survey and an ecological questionnaire were conducted to collect participant household locations and characteristics, while additional data on background malaria prevalence were obtained from a concurrent Malaria Transmission Intensity (MTI) survey. Negative binomial regression models were used to assess whether the efficacy of the vaccine varied by estimated background malaria prevalence, household roof type, or amount of nearby vegetation. RESULTS: Vaccine efficacy did not significantly vary by estimated malaria prevalence or by roof type. However, increased vegetation cover was associated with an increase in the efficacy of the three-dose primary RTS,S/AS01 series in the 18 months before the fourth dose and a decrease in the efficacy of the primary vaccine series in the second 18 months following, if the fourth dose was not given. Vegetation cover did not alter the efficacy of the fourth dose in a statistically or practically significant manner. CONCLUSIONS: Vegetation coverage in this study site might be a proxy for nearness to rivers or branching, shallow wetlands called "dambos" which could serve as breeding sites for mosquitoes. We observed statistically significant modification of the efficacy of RTS,S/AS01 by forest cover, suggesting that initial vaccine efficacy and the importance of the fourth dose varies based on ecological context. TRIAL REGISTRATION: Efficacy of GSK Biologicals' Candidate Malaria Vaccine (257049) Against Malaria Disease Caused by P. falciparum Infection in Infants and Children in Africa. NCT00866619 prospectively registered 20 March 2009.


Asunto(s)
Vacunas contra la Malaria/inmunología , Malaria Falciparum/epidemiología , Plasmodium falciparum/inmunología , Niño , Ambiente , Femenino , Sistemas de Información Geográfica , Humanos , Lactante , Malaria Falciparum/prevención & control , Malaui/epidemiología , Masculino , Análisis Espacial , Encuestas y Cuestionarios , Vacunación
6.
Malar J ; 18(1): 205, 2019 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-31234875

RESUMEN

BACKGROUND: Heterogeneity in the immune response to parasite infection is mediated in part by differences in host genetics, gender, and age group. In infants and young children, ongoing immunological maturation often results in increased susceptibility to infection and variable responses to drug treatment, increasing the risk of complications. Even though significant age-associated effects on host cytokine responses to Plasmodium falciparum infection have been identified, age-associated effects on uncomplicated malaria infection and anti-malarial treatment remain poorly understood. METHODS: In samples of whole blood from a cohort of naturally infected malaria-positive individuals with non-severe falciparum malaria in Malawi (n = 63 total; 34 infants and young children < 2 years old, 29 adults > 18 years old), blood cytokine levels and monocyte and dendritic cell frequencies were assessed at two timepoints: acute infection, and 4 weeks post anti-malarial treatment. The effects of age group, gender, and timepoint were modeled, and the role of these factors on infection and treatment outcomes was evaluated. RESULTS: Regardless of treatment timepoint, in this population age was significantly associated with overall blood haemoglobin, which was higher in adults, and plasma nitric oxide metabolites, IL-10, and TNF levels, which were higher in young children. There was a significant effect of age on the haemoglobin treatment response, whereby after treatment, levels increased in young children and decreased in adults. Furthermore, there were significant age-associated effects on treatment response for overall parasite load, IFN-γ, and IL-12(p40), and these effects were gender-dependent. Significant age effects on the overall levels and treatment response of myeloid dendritic cell frequencies were observed. In addition, within each age group, results showed continuous age effects on gametocyte levels (Pfs16), TNF, and nitric oxide metabolites. CONCLUSIONS: In a clinical study of young children and adults experiencing natural falciparum malaria infection and receiving anti-malarial treatment, age-associated signatures of infection and treatment responses in peripheral blood were identified. This study describes host markers that may indicate, and potentially contribute to, differential post-treatment outcomes for malaria in young children versus adults.


Asunto(s)
Antimaláricos/uso terapéutico , Biomarcadores/sangre , Malaria Falciparum/sangre , Malaria Falciparum/tratamiento farmacológico , Modelos Biológicos , Adulto , Factores de Edad , Recuento de Células Sanguíneas , Citocinas/sangre , Femenino , Humanos , Lactante , Malaui , Masculino , Carga de Parásitos , Factores Sexuales
7.
Pediatr Blood Cancer ; 66(11): e27954, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31397075

RESUMEN

INTRODUCTION: Sickle cell disease (SCD) is among the most common inherited hematologic diseases in sub-Saharan Africa (SSA). Historically, hydroxyurea administration in SSA has been restricted due to limited region-specific evidence for safety and efficacy. METHODS: We conducted a prospective observational cohort study of pediatric patients with SCD in Malawi. From January 2015 to November 2017, hydroxyurea at doses of 10-20 mg/kg/day was administered to children with clinically severe disease (targeted use policy). From December 2017 to July 2018, hydroxyurea was prescribed to all patients (universal use policy). RESULTS: Of 187 patients with SCD, seven (3.7%) died and 23 (12.3%) were lost to follow-up. The majority (135, 72.2%) were prescribed hydroxyurea, 59 (43.7%) under the targeted use policy and 76 (56.3%) under the universal use policy. There were no documented severe toxicities. Under the targeted use policy, children with SCD demonstrated absolute decreases in the rates of hospitalization (-4.1 per 1000 person-days; -7.2, -1.0; P = .004), fevers (-4.2 per 1000 person-days; -7.2, -1.1; P = .002), transfusions (-2.3 per 1000 person-days; 95% confidence interval: -4.9, 0.3; P = .06), and annual school absenteeism (-51.2 per person-year; -60.1, -42.3; P < .0001) within 6 months of hydroxyurea commencement. CONCLUSION: We successfully implemented universal administration of hydroxyurea to children with SCD at a tertiary hospital in Malawi. Similar to recently reported trials, hydroxyurea was safe and effective during routine programmatic experience, with clinical benefits particularly among high-risk children. This highlights the importance of continued widespread scale-up of hydroxyurea within SCD programs across SSA.


Asunto(s)
Anemia de Células Falciformes/tratamiento farmacológico , Países en Desarrollo , Hidroxiurea/uso terapéutico , Absentismo , Adolescente , Anemia de Células Falciformes/epidemiología , Transfusión Sanguínea/estadística & datos numéricos , Niño , Preescolar , Terapia Combinada , Femenino , Fiebre/epidemiología , Fiebre/etiología , Hemoglobinas/análisis , Hospitalización/estadística & datos numéricos , Hospitales Públicos/estadística & datos numéricos , Humanos , Hidroxiurea/efectos adversos , Hidroxiurea/provisión & distribución , Lactante , Cooperación Internacional , Malaui/epidemiología , Masculino , North Carolina , Pacientes Desistentes del Tratamiento , Utilización de Procedimientos y Técnicas , Estudios Prospectivos , Centros de Atención Terciaria/estadística & datos numéricos
8.
Matern Child Nutr ; 14(2): e12503, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-28851037

RESUMEN

We evaluated effects of antiretroviral (ARV) therapy and lipid-based nutrient supplements (LNSs) on iron, copper, and zinc in milk of exclusively breastfeeding HIV-infected Malawian mothers and their correlations with maternal and infant biomarkers. Human milk and blood at 2, 6, and 24 weeks post-partum and blood during pregnancy (≤30 weeks gestation) were collected from 535 mothers/infant-pairs in the Breastfeeding, Antiretrovirals, and Nutrition study. The participants received ARV, LNS, ARV and LNS, or no intervention from 0 to 28 weeks post-partum. ARVs negatively affected copper and zinc milk concentrations, but only at 2 weeks, whereas LNS had no effect. Among all treatment groups, approximately 80-90% of copper and zinc and <50% of iron concentrations met the current adequate intake for infants at 2 weeks and only 1-19% at 24 weeks. Pregnancy haemoglobin was negatively correlated with milk iron at 2 and 6 weeks (r = -.18, p < .02 for both). The associations of the milk minerals with each other were the strongest correlations observed (r = .11-.47, p < .05 for all); none were found with infant biomarkers. At 2 weeks, moderately anaemic women produced milk higher in iron when ferritin was higher or TfR lower. At 6 weeks, higher maternal α-1-acid glycoprotein and C-reactive protein were associated with higher milk minerals in mildly anaemic women. Infant TfR was lower when milk mineral concentrations were higher at 6 weeks and when mothers were moderately anaemic during pregnancy. ARV affects copper and zinc milk concentrations in early lactation, and maternal haemoglobin during pregnancy and lactation could influence the association between milk minerals and maternal and infant iron status and biomarkers of inflammation.


Asunto(s)
Fármacos Anti-VIH/farmacología , Cobre/metabolismo , Infecciones por VIH/tratamiento farmacológico , Hierro/metabolismo , Lípidos/farmacología , Leche Humana/efectos de los fármacos , Zinc/metabolismo , Adulto , Fármacos Anti-VIH/uso terapéutico , Biomarcadores/sangre , Lactancia Materna , Suplementos Dietéticos , Femenino , Hemoglobinas/metabolismo , Humanos , Lactante , Recién Nacido , Inflamación/sangre , Hierro/sangre , Lípidos/administración & dosificación , Malaui , Masculino , Leche Humana/metabolismo , Madres , Adulto Joven
9.
Malar J ; 16(1): 142, 2017 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-28388914

RESUMEN

BACKGROUND: The protective effect of insecticide-treated bed nets against individual-level malaria transmission is well known, however community-level effects are less understood. Protective effects from community-level bed net use against malaria transmission have been observed in clinical trials, however, the relationship is less clear outside of a controlled research setting. The objective of this research was to investigate the effect of community-level bed net use against malaria transmission outside of a bed net clinical trial setting in Lilongwe, Malawi following national efforts to scale-up ownership of long-lasting, insecticide-treated bed nets. METHODS: An annual, cross-sectional, household-randomized, malaria transmission intensity survey was conducted in Lilongwe, Malawi (2011-2013). Health, demographic, and geographic-location data were collected. Participant blood samples were tested for Plasmodium falciparum presence. The percentage of people sleeping under a bed net within 400-m and 1-km radii of all participants was measured. Mixed effects logistic regression models were used to measure the relationship between malaria prevalence and surrounding bed net coverage. Each year, 800 people were enrolled (400 <5 years; 200 5-19 years; 200 ≥20 years; total n = 2400). RESULTS: From 2011 to 2013, malaria prevalence declined from 12.9 to 5.6%, while bed net use increased from 53.8 to 78.6%. For every 1% increase in community bed net coverage, malaria prevalence decreased among children under 5 years old [adjusted odds ratio: 0.98 (0.96, 1.00)]. Similar effects were observed in participants 5-19 years [unadjusted odds ratio: 0.98 (0.97, 1.00)]; the effect was attenuated after adjusting for individual-level bed net use. Community coverage was not associated with malaria prevalence among adults ≥20 years. Supplemental analyses identified more pronounced indirect protective effects from community-level bed net use against malaria transmission among children under 5 years who were sleeping under a bed net [adjusted odds ratio: 0.97 (0.94, 0.99)], compared to children who were not sleeping under a bed net [adjusted odds ratio: 0.99 (0.97, 1.01)]. CONCLUSIONS: Malawi's efforts to scale up ownership of long-lasting, insecticide-treated bed nets are effective in increasing reported use. Increased community-level bed net coverage appears to provide additional protection against malaria transmission beyond individual use in a real-world context.


Asunto(s)
Transmisión de Enfermedad Infecciosa/prevención & control , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Malaria Falciparum/epidemiología , Malaria Falciparum/prevención & control , Control de Mosquitos/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Estudios Transversales , Composición Familiar , Femenino , Humanos , Lactante , Recién Nacido , Malaui/epidemiología , Masculino , Persona de Mediana Edad , Plasmodium falciparum , Prevalencia , Distribución Aleatoria , Adulto Joven
10.
Paediatr Perinat Epidemiol ; 31(2): 134-143, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28205255

RESUMEN

BACKGROUND: The relationship between mastitis and antiretroviral therapy among HIV-positive, breast-feeding women is unclear. METHODS: In the Breastfeeding, Antiretrovirals, and Nutrition (BAN) study, conducted in Lilongwe, Malawi, 2369 mother-infant pairs were randomized to a nutritional supplement group and to one of three treatment groups: maternal antiretroviral therapy (ART), infant nevirapine (NVP) or standard of care for 24 weeks of exclusive breast-feeding and 4 weeks of weaning. Among 1472 HIV-infected women who delivered live infants between 2004 and 2007, we estimated cumulative incidence functions and sub-distribution hazard ratios (HR) of mastitis or breast inflammation comparing women in maternal ART (n = 487) or infant nevirapine (n = 492) groups to the standard of care (n = 493). Nutritional supplement groups (743 took, 729 did not) were also compared. RESULTS: Through 28-weeks post-partum, 102 of 1472 women experienced at least one occurrence of mastitis or breast inflammation. The 28-week risk was higher for maternal ART (risk difference (RD) 4.5, 95% confidence interval (CI) 0.9, 8.1) and infant NVP (RD 3.6, 95% CI 0.3, 6.9) compared to standard of care. The hazard of late-appearing mastitis or breast inflammation (from week 5-28) was also higher for maternal ART (HR 6.7, 95% CI 2.0, 22.6) and infant NVP (HR 5.1, 95% CI 1.5, 17. 5) compared to the standard of care. CONCLUSIONS: Mastitis or breast inflammation while breast-feeding is a possible side effect for women taking prophylactic ART and women whose infants take NVP, warranting additional research in the context of postnatal HIV transmission.


Asunto(s)
Fármacos Anti-VIH/efectos adversos , Lactancia Materna , Infecciones por VIH/tratamiento farmacológico , Mastitis/inducido químicamente , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Adulto , Suplementos Dietéticos , Femenino , Infecciones por VIH/epidemiología , Humanos , Malaui/epidemiología , Mastitis/epidemiología , Atención Posnatal , Embarazo , Factores de Riesgo
11.
J Virol ; 89(19): 9952-61, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26202232

RESUMEN

UNLABELLED: Infants born to HIV-1-infected mothers in resource-limited areas where replacement feeding is unsafe and impractical are repeatedly exposed to HIV-1 throughout breastfeeding. Despite this, the majority of infants do not contract HIV-1 postnatally, even in the absence of maternal antiretroviral therapy. This suggests that immune factors in breast milk of HIV-1-infected mothers help to limit vertical transmission. We compared the HIV-1 envelope-specific breast milk and plasma antibody responses of clade C HIV-1-infected postnatally transmitting and nontransmitting mothers in the control arm of the Malawi-based Breastfeeding Antiretrovirals and Nutrition Study using multivariable logistic regression modeling. We found no association between milk or plasma neutralization activity, antibody-dependent cell-mediated cytotoxicity, or HIV-1 envelope-specific IgG responses and postnatal transmission risk. While the envelope-specific breast milk and plasma IgA responses also did not reach significance in predicting postnatal transmission risk in the primary model after correction for multiple comparisons, subsequent exploratory analysis using two distinct assay methodologies demonstrated that the magnitudes of breast milk total and secretory IgA responses against a consensus HIV-1 envelope gp140 (B.con env03) were associated with reduced postnatal transmission risk. These results suggest a protective role for mucosal HIV-1 envelope-specific IgA responses in the context of postnatal virus transmission. This finding supports further investigations into the mechanisms by which mucosal IgA reduces risk of HIV-1 transmission via breast milk and into immune interventions aimed at enhancing this response. IMPORTANCE: Infants born to HIV-1-infected mothers are repeatedly exposed to the virus in breast milk. Remarkably, the transmission rate is low, suggesting that immune factors in the breast milk of HIV-1-infected mothers help to limit transmission. We compared the antibody responses in plasma and breast milk of HIV-1-transmitting and -nontransmitting mothers to identify responses that correlated with reduced risk of postnatal HIV-1 transmission. We found that neither plasma nor breast milk IgG antibody responses were associated with risk of HIV-1 transmission. In contrast, the magnitudes of the breast milk IgA and secretory IgA responses against HIV-1 envelope proteins were associated with reduced risk of postnatal HIV-1 transmission. The results of this study support further investigations of the mechanisms by which mucosal IgA may reduce the risk of HIV-1 transmission via breastfeeding and the development of strategies to enhance milk envelope-specific IgA responses to reduce mother-to-child HIV transmission and promote an HIV-free generation.


Asunto(s)
Anticuerpos Anti-VIH/metabolismo , Infecciones por VIH/inmunología , Infecciones por VIH/transmisión , VIH-1 , Inmunoglobulina A/metabolismo , Transmisión Vertical de Enfermedad Infecciosa , Leche Humana/inmunología , Leche Humana/virología , Adulto , Anticuerpos Neutralizantes/metabolismo , Especificidad de Anticuerpos , Citotoxicidad Celular Dependiente de Anticuerpos , Lactancia Materna/efectos adversos , Femenino , Anticuerpos Anti-VIH/sangre , Infecciones por VIH/complicaciones , VIH-1/inmunología , Humanos , Inmunidad Mucosa , Inmunoglobulina A/sangre , Inmunoglobulina A Secretora/metabolismo , Inmunoglobulina G/metabolismo , Lactante , Recién Nacido , Malaui , Modelos Inmunológicos , Embarazo , Complicaciones Infecciosas del Embarazo/inmunología , Complicaciones Infecciosas del Embarazo/virología , Factores de Riesgo , Adulto Joven , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología
13.
Clin Infect Dis ; 61(3): 368-74, 2015 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-25900173

RESUMEN

BACKGROUND: Cotrimoxazole preventive therapy (CPT) is recommended for all human immunodeficiency virus (HIV)-exposed infants to avoid opportunistic infections. Cotrimoxazole has antimalarial effects and appears to reduce clinical malaria infections, but the impact on asymptomatic malaria infections is unknown. METHODS: We conducted an observational cohort study using data and dried blood spots (DBSs) from the Breastfeeding, Antiretrovirals and Nutrition study to evaluate the impact of CPT on malaria infection during peak malaria season in Lilongwe, Malawi. We compared malaria incidence 1 year before and after CPT implementation (292 and 682 CPT-unexposed and CPT-exposed infants, respectively), including only infants who remained HIV negative by 36 weeks of age. Malaria was defined as clinical, asymptomatic (using DBSs at 12, 24, and 36 weeks), or a composite outcome of clinical or asymptomatic. Linear and binomial regression with generalized estimating equations were used to estimate the association between CPT and malaria. Differences in characteristics of parasitemias and drug resistance polymorphisms by CPT status were also assessed in the asymptomatic infections. RESULTS: CPT was associated with a 70% (95% confidence interval, 53%-81%) relative reduction in the risk of asymptomatic infection between 6 and 36 weeks of age. CPT appeared to provide temporary protection against clinical malaria and more sustained protection against asymptomatic infections, with no difference in parasitemia characteristics. CONCLUSIONS: CPT appears to reduce overall malaria infections, with more prolonged impacts on asymptomatic infections. Asymptomatic infections are potentially important reservoirs for malaria transmission. Therefore, CPT prophylaxis may have important individual and public health benefits.


Asunto(s)
Antimaláricos/uso terapéutico , Malaria/tratamiento farmacológico , Malaria/epidemiología , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico , Antimaláricos/administración & dosificación , Antimaláricos/farmacología , Infecciones Asintomáticas , Resistencia a Medicamentos , Femenino , Infecciones por VIH , Humanos , Lactante , Malaria/parasitología , Malaui/epidemiología , Masculino , Parasitemia/tratamiento farmacológico , Parasitemia/epidemiología , Parasitemia/parasitología , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/genética , Distribución Aleatoria , Combinación Trimetoprim y Sulfametoxazol/administración & dosificación , Combinación Trimetoprim y Sulfametoxazol/farmacología
14.
J Nutr ; 145(8): 1950-7, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26156797

RESUMEN

BACKGROUND: Little is known about the influence of antiretroviral therapy with or without micronutrient supplementation on the micronutrient concentrations of HIV-infected lactating women in resource-constrained settings. OBJECTIVE: We examined associations of highly active antiretroviral therapy (HAART) and lipid-based nutrient supplements (LNS) with concentrations of selected micronutrients in HIV-infected Malawian women at 24 wk postpartum. METHODS: Plasma micronutrient concentrations were measured in a subsample (n = 690) of Breastfeeding, Antiretrovirals, and Nutrition (BAN) study participants who were randomly assigned at delivery to receive HAART, LNS, HAART+LNS, or no HAART/no LNS (control). HAART consisted of protease inhibitor-based triple therapy. LNS (140 g/d) met energy and micronutrient requirements of lactation. Multivariable linear regression tested the association of HAART and LNS, plus their interaction, with micronutrient concentrations, controlling for season, baseline viral load, and baseline CD4 count. RESULTS: We found significant HAART by LNS interactions for folate (P = 0.051), vitamin B-12 (P < 0.001), and transferrin receptors (TfRs) (P = 0.085). HAART was associated with lower folate (with LNS: -27%, P < 0.001; without LNS: -12%, P = 0.040) and higher TfR concentrations (with LNS: +14%, P = 0.004; without LNS: +28%, P < 0.001), indicating iron deficiency. LNS increased folate (with HAART: +17%, P = 0.037; without HAART: +39%, P < 0.001) and decreased TfR concentrations (with HAART only: -12%, P = 0.023). HAART was associated with lower vitamin B-12 concentrations only when LNS was present (-18%, P = 0.001), whereas LNS increased vitamin B-12 only when no HAART was present (+27%, P < 0.001). HAART, but not LNS, was associated with higher retinol-binding protein (RBP; +10%, P = 0.007). We detected no association of HAART or LNS with selenium, ferritin, or hemoglobin. CONCLUSION: The association of HAART with lower folate, iron deficiency, and higher RBP plus the attenuation of LNS effects on folate and vitamin B-12 when combined with HAART has implications for the health of lactating HIV-infected women taking HAART in prevention of mother-to-child transmission programs. This trial was registered at clinicaltrials.gov as NCT00164736.


Asunto(s)
Antirretrovirales/uso terapéutico , Suplementos Dietéticos , Infecciones por VIH/sangre , Infecciones por VIH/tratamiento farmacológico , Lípidos/química , Micronutrientes/sangre , Adulto , Antirretrovirales/administración & dosificación , Terapia Antirretroviral Altamente Activa , Femenino , Infecciones por VIH/epidemiología , Humanos , Malaui/epidemiología , Masculino , Adulto Joven
15.
BMC Infect Dis ; 15: 328, 2015 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-26265222

RESUMEN

BACKGROUND: We established Safeguard the Family (STF) to support Ministry of Health (MoH) scale-up of universal antiretroviral therapy (ART) for HIV-infected pregnant and breastfeeding women (Option B+) and to strengthen the prevention of mother-to-child transmission (PMTCT) cascade from HIV testing and counseling (HTC) through maternal ART provision and post-delivery early infant HIV diagnosis (EID). To these ends, we implemented the following interventions in 5 districts: 1) health worker training and mentorship; 2) couples' HTC and male partner involvement; 3) women's psychosocial support groups; and 4) health and laboratory system strengthening for EID. METHODS: We conducted a serial cross-sectional study using facility-level quarterly (Q) program data and individual-level infant HIV-1 DNA PCR data to evaluate STF performance on PMTCT indicators for project years (Y) 1 (April-December 2011) through 3 (January-December 2013), and compared these results to national averages. RESULTS: Facility-level uptake of HTC, ART, infant nevirapine prophylaxis, and infant DNA PCR testing increased significantly from quarterly baselines of 66 % (n/N = 32,433/48,804), 23 % (n/N = 442/1,958), 1 % (n/N = 10/1,958), and 52 % (n/N = 1,385/2,644) to 87 % (n/N = 39,458/45,324), 96 % (n/N = 2,046/2,121), 100 % (n/N = 2,121/2,121), and 62 % (n/N = 1,462/2,340), respectively, by project end (all p < 0.001). Quarterly HTC, ART, and infant nevirapine prophylaxis uptake outperformed national averages over years 2-3. While transitioning EID laboratory services to MoH, STF provided first-time HIV-1 DNA PCR testing for 2,226 of 11,261 HIV-exposed infants (20 %) tested in the MoH EID program in STF districts from program inception (Y2) through Y3. Of these, 78 (3.5 %) tested HIV-positive. Among infants with complete documentation (n = 608), median age at first testing decreased from 112 days (interquartile range, IQR: 57-198) in Y2 to 76 days (IQR: 46-152) in Y3 (p < 0.001). During Y3 (only year with national data for comparison), non-significantly fewer exposed infants tested HIV-positive (3.6 %) at first testing in STF districts than nationally (4.1 %) (p = 0.4). CONCLUSIONS: STF interventions, integrated within the MoH Option B+ program, achieved favorable HTC, maternal ART, infant prophylaxis, and EID services uptake, and a low proportion of infants found HIV-infected at first DNA PCR testing. Continued investments are needed to strengthen the PMTCT cascade, particularly around EID.


Asunto(s)
Terapia Antirretroviral Altamente Activa , Infecciones por VIH/tratamiento farmacológico , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Adulto , Lactancia Materna , Estudios Transversales , Diagnóstico Precoz , Femenino , Infecciones por VIH/transmisión , Humanos , Lactante , Recién Nacido , Malaui , Masculino , Profilaxis Posexposición , Periodo Posparto , Embarazo , Atención Prenatal , Evaluación de Programas y Proyectos de Salud , Adulto Joven
16.
J Nutr ; 144(3): 367-74, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24381222

RESUMEN

Infant iron status at birth is influenced by maternal iron status during pregnancy; however, there are limited data on the extent to which maternal iron status is associated with infant iron status during exclusive breastfeeding. We evaluated how maternal and infant hemoglobin and iron status [soluble transferrin receptors (TfR) and ferritin] were related during exclusive breastfeeding in HIV-infected women and their infants. The Breastfeeding, Antiretrovirals, and Nutrition Study was a randomized controlled trial in Lilongwe, Malawi, in which HIV-infected women were assigned with a 2 × 3 factorial design to a lipid-based nutrient supplement (LNS), or no LNS, and maternal, infant, or no antiretroviral drug, and followed for 24 wk. Longitudinal models were used to relate postpartum maternal hemoglobin (n = 1926) to concurrently measured infant hemoglobin, adjusting for initial infant hemoglobin values. In a subsample, change in infant iron status (hemoglobin, log ferritin, log TfR) between 2 (n = 352) or 6 wk (n = 167) and 24 wk (n = 519) was regressed on corresponding change in the maternal indicator, adjusting for 2 or 6 wk values. A 1 g/L higher maternal hemoglobin at 12, 18, and 24 wk was associated with a 0.06 g/L (P = 0.01), 0.10 g/L (P < 0.001), and 0.06 g/L (P = 0.01), respectively, higher infant hemoglobin. In the subsample, a reduction in maternal log TfR and an increase in hemoglobin from initial measurement to 24 wk were associated with the same pattern in infant values (log TfR ß = -0.18 mg/L, P < 0.001; hemoglobin ß = 0.13 g/L, P = 0.01). Given the observed influence of maternal and initial infant values, optimizing maternal iron status in pregnancy and postpartum is important to protect infant iron status. This trial was registered at clinicaltrials.gov as NCT00164736.


Asunto(s)
Lactancia Materna , Suplementos Dietéticos , Hemoglobinas/metabolismo , Hierro de la Dieta/administración & dosificación , Hierro de la Dieta/sangre , Receptores de Transferrina/sangre , Adulto , Antirretrovirales/administración & dosificación , Biomarcadores/sangre , Femenino , Ferritinas/sangre , Infecciones por VIH , Humanos , Lactante , Modelos Lineales , Estudios Longitudinales , Malaui/epidemiología , Masculino , Madres , Estado Nutricional , Periodo Posparto/fisiología , Embarazo , Adulto Joven
17.
J Infect Dis ; 208(4): 653-61, 2013 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-23687226

RESUMEN

BACKGROUND: Increased intestinal permeability may be one of the mechanisms of transmission of human immunodeficiency virus (HIV) to infants through breast-feeding. Intestinal permeability correlates with microbial translocation, which can be measured through quantification of bacterial lipopolysaccharide (LPS). METHODS: We evaluated levels of plasma LPS (by the Limulus amebocyte lysate assay) and immune activation markers in serial specimens from infants exposed to but uninfected with HIV and infants infected with HIV from the Breastfeeding, Antiretrovirals, and Nutrition (BAN) study. RESULTS: Plasma LPS levels increased after infants in the BAN study were weaned from the breast, at 24 weeks of age. Cotrimoxazole prophylaxis was associated with higher plasma LPS levels (P = .004). Infants with HIV infection had higher LPS levels, compared with uninfected infants (P = .004). Higher preinfection plasma LPS levels were a significant predictor of infant HIV infection through breast-feeding (hazard ratio = 1.60 for every unit increase in plasma LPS level; P = .01) and of lower infant length-for-age z scores (P = .02). CONCLUSIONS: These findings suggest that disruption in intestinal integrity is a mechanism of HIV transmission to infants through breast-feeding. Weaning from breast milk and use of antibiotic prophylaxis was associated with increased levels of microbial translocation, which could facilitate HIV entry through the intestine. Complementary approaches to enhance intestinal mucosal integrity in the infant may further reduce breast-feeding transmission of HIV.


Asunto(s)
Lactancia Materna , Infecciones por VIH/transmisión , Transmisión Vertical de Enfermedad Infecciosa , Mucosa Intestinal/inmunología , Mucosa Intestinal/fisiología , Traslocación Bacteriana , Femenino , Humanos , Lactante , Recién Nacido , Prueba de Limulus , Lipopolisacáridos/sangre , Masculino , Embarazo
18.
Lancet ; 379(9835): 2449-2458, 2012 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-22541418

RESUMEN

BACKGROUND: In resource-limited settings where no safe alternative to breastfeeding exists, WHO recommends that antiretroviral prophylaxis be given to either HIV-infected mothers or infants throughout breastfeeding. We assessed the effect of 28 weeks of maternal or infant antiretroviral prophylaxis on postnatal HIV infection at 48 weeks. METHODS: The Breastfeeding, Antiretrovirals, and Nutrition (BAN) Study was undertaken in Lilongwe, Malawi, between April 21, 2004, and Jan 28, 2010. 2369 HIV-infected breastfeeding mothers with a CD4 count of 250 cells per µL or more and their newborn babies were randomly assigned with a variable-block design to one of three, 28-week regimens: maternal triple antiretroviral (n=849); daily infant nevirapine (n=852); or control (n=668). Patients and local clinical staff were not masked to treatment allocation, but other study investigators were. All mothers and infants received one dose of nevirapine (mother 200 mg; infant 2 mg/kg) and 7 days of zidovudine (mother 300 mg; infants 2 mg/kg) and lamivudine (mothers 150 mg; infants 4 mg/kg) twice a day. Mothers were advised to wean between 24 weeks and 28 weeks after birth. The primary endpoint was HIV infection by 48 weeks in infants who were not infected at 2 weeks and in all infants randomly assigned with censoring at loss to follow-up. This trial is registered with ClinicalTrials.gov, number NCT00164736. FINDINGS: 676 mother-infant pairs completed follow-up to 48 weeks or reached an endpoint in the maternal-antiretroviral group, 680 in the infant-nevirapine group, and 542 in the control group. By 32 weeks post partum, 96% of women in the intervention groups and 88% of those in the control group reported no breastfeeding since their 28-week visit. 30 infants in the maternal-antiretroviral group, 25 in the infant-nevirapine group, and 38 in the control group became HIV infected between 2 weeks and 48 weeks of life; 28 (30%) infections occurred after 28 weeks (nine in maternal-antiretroviral, 13 in infant-nevirapine, and six in control groups). The cumulative risk of HIV-1 transmission by 48 weeks was significantly higher in the control group (7%, 95% CI 5-9) than in the maternal-antiretroviral (4%, 3-6; p=0·0273) or the infant-nevirapine (4%, 2-5; p=0·0027) groups. The rate of serious adverse events in infants was significantly higher during 29-48 weeks than during the intervention phase (1·1 [95% CI 1·0-1·2] vs 0·7 [0·7-0·8] per 100 person-weeks; p<0·0001), with increased risk of diarrhoea, malaria, growth faltering, tuberculosis, and death. Nine women died between 2 weeks and 48 weeks post partum (one in maternal-antiretroviral group, two in infant-nevirapine group, six in control group). INTERPRETATION: In resource-limited settings where no suitable alternative to breastfeeding is available, antiretroviral prophylaxis given to mothers or infants might decrease HIV transmission. Weaning at 6 months might increase infant morbidity. FUNDING: US Centers for Disease Control and Prevention.


Asunto(s)
Antirretrovirales/administración & dosificación , Infecciones por VIH/prevención & control , VIH-1 , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Adulto , Lactancia Materna , Femenino , Estudios de Seguimiento , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/transmisión , Humanos , Recién Nacido , Lamivudine/administración & dosificación , Nevirapina/administración & dosificación , Embarazo , Adulto Joven , Zidovudina/administración & dosificación
19.
N Engl J Med ; 362(24): 2271-81, 2010 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-20554982

RESUMEN

BACKGROUND: We evaluated the efficacy of a maternal triple-drug antiretroviral regimen or infant nevirapine prophylaxis for 28 weeks during breast-feeding to reduce postnatal transmission of human immunodeficiency virus type 1 (HIV-1) in Malawi. METHODS: We randomly assigned 2369 HIV-1-positive, breast-feeding mothers with a CD4+ lymphocyte count of at least 250 cells per cubic millimeter and their infants to receive a maternal antiretroviral regimen, infant nevirapine, or no extended postnatal antiretroviral regimen (control group). All mothers and infants received perinatal prophylaxis with single-dose nevirapine and 1 week of zidovudine plus lamivudine. We used the Kaplan-Meier method to estimate the cumulative risk of HIV-1 transmission or death by 28 weeks among infants who were HIV-1-negative 2 weeks after birth. Rates were compared with the use of the log-rank test. RESULTS: Among mother-infant pairs, 5.0% of infants were HIV-1-positive at 2 weeks of life. The estimated risk of HIV-1 transmission between 2 and 28 weeks was higher in the control group (5.7%) than in either the maternal-regimen group (2.9%, P=0.009) or the infant-regimen group (1.7%, P<0.001). The estimated risk of infant HIV-1 infection or death between 2 and 28 weeks was 7.0% in the control group, 4.1% in the maternal-regimen group (P=0.02), and 2.6% in the infant-regimen group (P<0.001). The proportion of women with neutropenia was higher among those receiving the antiretroviral regimen (6.2%) than among those in either the nevirapine group (2.6%) or the control group (2.3%). Among infants receiving nevirapine, 1.9% had a hypersensitivity reaction. CONCLUSIONS: The use of either a maternal antiretroviral regimen or infant nevirapine for 28 weeks was effective in reducing HIV-1 transmission during breast-feeding. (ClinicalTrials.gov number, NCT00164736.)


Asunto(s)
Antirretrovirales/uso terapéutico , Lactancia Materna , Infecciones por VIH/transmisión , VIH-1 , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Adulto , Antirretrovirales/efectos adversos , Recuento de Linfocito CD4 , Hipersensibilidad a las Drogas/etiología , Quimioterapia Combinada , Femenino , Infecciones por VIH/tratamiento farmacológico , Seronegatividad para VIH , Humanos , Recién Nacido , Estimación de Kaplan-Meier , Lamivudine/uso terapéutico , Masculino , Neutropenia/inducido químicamente , Nevirapina/efectos adversos , Nevirapina/uso terapéutico , Embarazo , Factores de Riesgo , Síndrome de Stevens-Johnson/inducido químicamente , Adulto Joven , Zidovudina/uso terapéutico
20.
mSphere ; 8(1): e0058522, 2023 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-36622252

RESUMEN

Important questions remain on how hormonal contraceptives alter the local immune environment and the microbiota in the female genital tract and how such effects may impact susceptibility to HIV infection. We leveraged samples from a previously conducted clinical trial of Malawian women with (n = 73) and without (n = 24) HIV infection randomized to depot medroxyprogesterone acetate (DMPA) or the levonogestrel implant in equal numbers within each group and determined the effects of these hormonal contraceptives (HCs) on the vaginal immune milieu and the composition of the vaginal microbiota. Longitudinal data for soluble immune mediators, measured by multiplex bead arrays and enzyme-linked immunosorbent assays (ELISAs), and vaginal microbiota, assessed by 16S rRNA gene amplicon, were collected prior to and over a period of 180 days post-HC initiation. DMPA and levonogestrel had only minimal effects on the vaginal immune milieu and microbiota. In women with HIV, with the caveat of a small sample size, there was an association between the median log10 change in the interleukin-12 (IL-12)/IL-10 ratio in vaginal fluid at day 180 post-HC compared to baseline when these women were classified as having a community state type (CST) IV vaginal microbiota and were randomized to DMPA. Long-lasting alterations in soluble immune markers or shifts in microbiota composition were not observed. Furthermore, women with HIV did not exhibit increased viral shedding in the genital tract after HC initiation. Consistent with the results of the ECHO (Evidence for Contraceptive Options and HIV Outcomes) trial, our data imply that the progestin-based HC DMPA and levonorgestrel are associated with minimal risk for women with HIV. (This study has been registered at ClinicalTrials.gov under registration no. NCT02103660). IMPORTANCE The results of the Evidence for Contraceptive Options and HIV Outcomes (ECHO) trial, the first large randomized controlled clinical trial comparing the HIV acquisition risk of women receiving DMPA, the levonorgestrel (LNG) implant, or the copper intrauterine device (IUD), did not reveal an increased risk of HIV acquisition for women on any of these three contraceptives. Our study results confirm that the two different progestin-based hormonal contraceptives DMPA and levonogestrel will not increase the risk for HIV infection. Furthermore, DMPA and levonogestrel have only minimal effects on the immune milieu and the microbiota in the vaginal tract, attesting to the safety of these hormonal contraceptives.


Asunto(s)
Agentes Anticonceptivos Hormonales , Infecciones por VIH , Microbiota , Femenino , Humanos , Anticonceptivos/efectos adversos , Anticonceptivos/uso terapéutico , Citocinas/efectos de los fármacos , Levonorgestrel/efectos adversos , Levonorgestrel/uso terapéutico , Malaui , Acetato de Medroxiprogesterona/efectos adversos , Acetato de Medroxiprogesterona/uso terapéutico , Microbiota/efectos de los fármacos , Progestinas/farmacología , ARN Ribosómico 16S , Agentes Anticonceptivos Hormonales/efectos adversos , Agentes Anticonceptivos Hormonales/uso terapéutico
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA