Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
1.
Artículo en Inglés | MEDLINE | ID: mdl-39284005

RESUMEN

The human immunodeficiency virus (HIV) heavily affects women from resource-limited settings who are vulnerable to potentially harmful mycotoxins including aflatoxin B1 (AFB1), fumonisin B1 (FB1) and ochratoxin A (OTA). We aimed to conduct biomonitoring and ascertain the determinants of maternal mycotoxin exposure in pregnancy, lactation and post-lactation periods. We conducted a retrospective longitudinal study in HIV-infected and HIV-uninfected women from Harare, Zimbabwe. 175 and 125 random urine samples in pregnancy and 24 months after delivery (post-lactation) respectively were analysed for aflatoxin M1 (AFM1) and FB1 by ELISA. 6 weeks after delivery (lactation), 226 and 262 breast milk (BM) samples were analysed for AFM1 and OTA respectively by ELISA. The association of demographics and food consumption with mycotoxins was evaluated using multivariable logistic regression. In HIV-infected, urinary AFM1 was detected in 46/94 (Median: 0.05; Range: 0.04-0.46 ng mL-1) in pregnancy and 47/66 (Median: 0.05; Range: 0.04-1.01 ng mL-1) post-lactation. Urinary FB1 was detected in 86/94 (Median: 1.39; Range: 0.17-6.02 ng mL-1) in pregnancy and 56/66 (Median: 0.72; Range: 0.20-3.81 ng mL-1) post-lactation. BM AFM1 was detected in 28/110 (Median: 7.24; Range: 5.96-29.80 pg mL-1) and OTA in 11/129 (Median: 0.20; Range: 0.14-0.65 ng mL-1). In HIV-uninfected, urinary AFM1 was detected in 48/81 (Median: 0.05; Range: 0.04-1.06 ng mL-1) in pregnancy and 41/59 (Median: 0.05; Range: 0.04-0.52 ng mL-1) post-lactation. Urinary FB1 was detected in 74/81 (Median: 1.15; Range: 0.17-6.16 ng mL-1) in pregnancy and 55/59 (Median: 0.96; Range: 0.20-2.82 ng mL-1) post-lactation. BM AFM1 was detected in 38/116 (Median: 7.70; Range: 6.07-31.75 pg mL-1) and OTA in 4/133 (Median: 0.24; Range: 0.18-0.83 ng mL-1). Location, wealth, and peanut butter consumption were determinants of AFB1 exposure. HIV infection, BMI, location, rainy season, unemployment, and age were determinants of FB1 exposure. Women especially those pregnant and/or HIV-infected are at risk of adverse effects of mycotoxins.

2.
Front Public Health ; 12: 1283350, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38645447

RESUMEN

The WHO African Region had 81 million people with chronic hepatitis B in 2019, which remains a silent killer. Hepatitis B virus (HBV), hepatitis delta virus (HDV), and HIV can be transmitted from the mother to child. If the HBV infection is acquired at infancy, it may lead to chronic hepatitis B in 90% of the cases. WHO reports that 6.4 million children under 5 years live with chronic hepatitis B infection worldwide. The prevention of mother-to-child transmission (PMTCT) of HBV is therefore critical in the global elimination strategy of viral hepatitis as we take lessons from PMTCT of HIV programs in Africa. We sought to create a network of multidisciplinary professional and civil society volunteers with the vision to promote cost-effective, country-driven initiatives to prevent the MTCT of HBV in Africa. In 2018, the Mother-Infant Cohort Hepatitis B Network (MICHep B Network) with members from Cameroon, Zimbabwe, and the United Kingdom and later from Chad, Gabon, and Central African Republic was created. The long-term objectives of the network are to organize capacity-building and networking workshops, create awareness among pregnant women, their partners, and the community, promote the operational research on MTCT of HBV, and extend the network activities to other African countries. The Network organized in Cameroon, two "Knowledge, Attitude and Practice" (KAP) surveys, one in-depth interview of 45 health care workers which revealed a high acceptability of the hepatitis B vaccine by families, two in-person workshops in 2018 and 2019, and one virtual in 2021 with over 190 participants, as well as two workshops on grant writing, bioethics, and biostatistics of 30 postgraduate students. Two HBV seroprevalence studies in pregnant women were conducted in Cameroon and Zimbabwe, in which a prevalence of 5.8% and 2.7%, respectively, was reported. The results and recommendations from the MICHep B Network activities could be implemented in countries of the MICHep B Network and beyond, with the goal of providing free birth dose vaccine against hepatitis B in Africa.


Asunto(s)
Hepatitis B , Transmisión Vertical de Enfermedad Infecciosa , Humanos , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Femenino , África/epidemiología , Embarazo , Hepatitis B/prevención & control , Hepatitis B/transmisión , Lactante , Erradicación de la Enfermedad , Adulto , Complicaciones Infecciosas del Embarazo/prevención & control , Recién Nacido
3.
Front Immunol ; 14: 1280262, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38045684

RESUMEN

Introduction: Combination antiretroviral therapy (cART) effectively controls HIV; however, chronic low-level viremia and gut microbiota dysbiosis remain significant drivers of gut and systemic inflammation. In this study, we explored the relationship between gut microbiota composition, intestinal inflammation, microbial translocation, and systemic inflammation in women on cART in Sub-Saharan Africa. Methods: We conducted a study in HIV-infected and HIV-uninfected lactating women followed up at 6 weeks and 6 months postpartum in Harare, Zimbabwe. We used 16S ribosomal Ribonucleic Acid (rRNA) sequencing and MesoScale Discovery V-Plex assays to examine the gut microbiome and to quantify plasma inflammatory biomarkers, respectively. In addition, we measured fecal calprotectin, plasma lipopolysaccharide-binding protein (LBP), and soluble cluster of differentiation 14 (sCD14) by enzyme-linked immunosorbent assay to assess gut inflammation, microbial translocation, and monocyte/macrophage activation. Results: A group of 77 lactating women were studied, of which 35% were HIV-infected. Fecal calprotectin levels were similar by HIV status at both follow-up time points. In the HIV-infected group at 6 weeks postpartum, fecal calprotectin was elevated: median (interquartile range) [158.1 µg/g (75.3-230.2)] in women who had CD4+ T-lymphocyte counts <350 cells/µL compared with those with ≥350 cells/µL [21.1 µg/g (0-58.4)], p = 0.032. Plasma sCD14 levels were significantly higher in the HIV-infected group at both 6 weeks and 6 months postpartum, p < 0.001. Plasma LBP levels were similar, but higher levels were observed in HIV-infected women with elevated fecal calprotectin. We found significant correlations between fecal calprotectin, LBP, and sCD14 with proinflammatory cytokines. Gut microbial alpha diversity was not affected by HIV status and was not affected by use of antibiotic prophylaxis. HIV significantly affected microbial beta diversity, and significant differences in microbial composition were noted. The genera Slackia and Collinsella were relatively more abundant in the HIV-infected group, whereas a lower relative abundance of Clostriduim sensu_stricto_1 was observed. Our study also found correlations between gut microbial taxa abundance and systemic inflammatory biomarkers. Discussion and conclusion: HIV-infected lactating women had increased immune activation and increased microbial translocation associated with increased gut inflammation. We identified correlations between the gut inflammation and microbial composition, microbial translocation, and systemic inflammation. The interplay of these parameters might affect the health of this vulnerable population.


Asunto(s)
Microbioma Gastrointestinal , Infecciones por VIH , Humanos , Femenino , Terapia Antirretroviral Altamente Activa , Receptores de Lipopolisacáridos , Lactancia , Infecciones por VIH/tratamiento farmacológico , Zimbabwe , Inflamación/tratamiento farmacológico , Biomarcadores , Complejo de Antígeno L1 de Leucocito
4.
BMC Infect Dis ; 23(1): 736, 2023 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-37891471

RESUMEN

BACKGROUND: Despite the availability of an effective vaccine, chronic hepatitis B virus (HBV) infections remain a major cause of liver cirrhosis and hepatocellular carcinoma. HBV burden in pregnancy, risk factors and the timing of mother to child transmission remain poorly described especially during this era of lifelong use of Tenofovir/Lamivudine/Efavirenz as firstline for HIV treatment. We aimed to determine the burden of HBV in pregnancy and infants receiving their first dose of HBV vaccine 6 weeks after birth in a high HIV-prevalence setting. METHODS: Pregnant women ≥ 20 weeks' gestational age were enrolled and followed up as mother-infant dyads from delivery, 6, 24 and 96 weeks after birth. HBV surface antigen (HBsAg) was tested (fresh plasma, immunochromatography) in pregnancy. Women testing HBsAg-seropositive were further evaluated for other four HBV-biomarkers. Maternally HBV exposed babies were tested for HBsAg from birth and HBs-antibodies from 6 months of age. Maternal-infant factors were tested in univariable and multivariable analyses for predictors of HBsAg-seropositivity. RESULTS: Six hundred HIV-uninfected and 608 HIV-infected women on Tenofovir/Lamivudine/Efavirenz-regimen with median (interquartile range) 350: (87-1477) days of therapy use were enrolled. The overall HBsAg-seroprevalence was 32/1208: 2.65%, 95% confidence interval (CI) [1.74, 3.55]; being 7/600: 1.17%, 95% CI [0.37, 1.97] and 25/608: 4.11%, 95% CI [2.52, 5.68] in HBsAg-monoinfected and HBsAg/HIV-coinfected respectively, disproportionately detected in 31/32: 96.9%, 95% CI [90.8, 100] women presumably HBV-unvaccinated in infancy. HBV exposed babies tended to be born prematurely (< 37 weeks); 15.2% versus 9.9% in the HBV-unexposed, p = 0.009. In multivariate logistic regression-models with variable elimination, HIV-infection and reported tooth extractions predicted antenatal HBsAg-seropositivity; odds ratios (CI): 3.85 (1.61-10.7) and 2.46 (1.07-5.34), respectively. None of the exposed infants were HBsAg-seropositive neither before nor after 6 weeks of age. No HBs-antibodies were detected in 23.3% of HBsAg-exposed infants at two years despite having successfully completed the HBV vaccination schedule. CONCLUSION: Low and moderate HBV endemics were observed in HIV-uninfected and HIV-infected pregnant women, respectively. This underscores the need to routinely screen for HBV in pregnancy, especially the HIV-infected attending antenatal-care. Being HIV-infected and reported tooth extractions were independent risk factors for maternal HBsAg-seropositivity. Vertical and child horizontal transmissions were both absent, probably due to ~ the 50% frequency of antenatal anti-HBe-antibodies observed. Of concern was the absence of anti-HBs-antibodies in 23.3% of fully vaccinated/maternally HBV-exposed infants by two years. Absence of molecular diagnosis may have underestimated HBV burden. TRIAL REGISTRATION: www. CLINICALTRIALS: gov , trial registration number: NCT04087239.


Asunto(s)
Infecciones por VIH , Hepatitis B Crónica , Hepatitis B , Complicaciones Infecciosas del Embarazo , Lactante , Niño , Femenino , Embarazo , Humanos , Virus de la Hepatitis B/genética , Antígenos de Superficie de la Hepatitis B , Hepatitis B Crónica/complicaciones , Hepatitis B Crónica/epidemiología , Hepatitis B Crónica/tratamiento farmacológico , Resultado del Embarazo , Hepatitis B/complicaciones , Hepatitis B/epidemiología , Hepatitis B/prevención & control , Lamivudine/uso terapéutico , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Prevalencia , Estudios Seroepidemiológicos , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Factores de Riesgo , Tenofovir/uso terapéutico , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Vacunas contra Hepatitis B , Anticuerpos contra la Hepatitis B , Madres
5.
Front Immunol ; 14: 1182217, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37350953

RESUMEN

Commencing lifelong antiretroviral therapy (ART) immediately following HIV diagnosis (Option B+) has dramatically improved the health of HIV-infected women and their children, with the majority being of HIV-exposed children born uninfected (HEU). This success has led to an increasing population of HIV-infected women receiving ART during pregnancy and children exposed to ART in utero. Nonetheless, a small proportion of children are still infected with HIV (HEI) each year. HEI children suffer from reduced immunocompetence and host-defence, due to CD4+ T lymphocyte depletion, but also dysregulation of other immune cells including CD8+ T lymphocytes, natural killer (NK) cells, macrophages including B lymphocytes. Furthermore, although HEU children are uninfected, altered immune responses are observed and associated with increased vulnerability to infections. The mechanisms underlying immune dysregulation in HEU children remain poorly described. Building on early studies, emerging data suggests that HIV/ART exposure early in life affects cell metabolic function of HEU children. Prenatal HIV/ART exposure has been associated with dysregulation of mitochondria, including impaired DNA polymerase activity. Furthermore, dysregulation of oxidative phosphorylation (OXPHOS) causes a decreased generation of adenosine triphosphate (ATP) and increased production of reactive oxygen species (ROS), resulting in oxidative stress. These altered metabolic processes can affect immune cell viability and immune responses. Recent studies have indicated that immune-metabolic dysregulation may contribute to HIV-associated pathogenesis and clinical observations associated with HIV and ART exposure in HEU/HEI children. Given the critical role metabolic processes in immune cell functioning, immune-metabolic dysregulation in HEU and HEI children may have implications in effective host-defence responses against pathogens, as well as efficacy of standard ART regimens and future novel HIV cure approaches in HEI children. At the same time, targeting metabolic pathways of immune cells may provide safer and novel approaches for HIV cure strategies. Here, we review the current literature investigating immune-metabolic dysregulation in paediatric HIV pathogenesis.


Asunto(s)
Infecciones por VIH , Complicaciones Infecciosas del Embarazo , Embarazo , Humanos , Niño , Femenino , VIH , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Infecciones por VIH/tratamiento farmacológico , Parto , Linfocitos T CD4-Positivos
6.
AIDS ; 37(9): 1367-1376, 2023 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-37070556

RESUMEN

OBJECTIVE: To determine immune-metabolic dysregulation in children born to women living with HIV. METHODS: Longitudinal immune-metabolomic analyses of plasma of 32 pregnant women with HIV (WHIV) and 12 uninfected women and their children up to 1.5 years of age were performed. RESULTS: Using liquid chromatography-mass spectrometry and a multiplex bead assay, 280 metabolites (57 amino acids, 116 positive lipids, 107 signalling lipids) and 24 immune mediators (e.g. cytokines) were quantified. combinational antiretroviral therapy (cART) exposure was categorized as cART initiation preconception (long), cART initiation postconception up to 4 weeks before birth (medium) and cART initiation within 3 weeks of birth (short). Plasma metabolite profiles differed between HIV-exposed-uninfected (HEU)-children with long cART exposure compared to HIV-unexposed-children (HUU). Specifically, higher levels of methionine-sulfone, which is associated with oxidative stress, were detected in HEU-children with long cART exposure compared to HUU-children. High infant methionine-sulfone levels were reflected by high prenatal plasma levels in the mother. Increased methionine-sulfone levels in the children were associated with decreased growth, including both weight and length. CONCLUSION: These findings based on longitudinal data demonstrate that dysregulation of metabolite networks associated with oxidative stress in children born to WHIV is associated with restricted infant growth.


Asunto(s)
Infecciones por VIH , Complicaciones Infecciosas del Embarazo , Lactante , Humanos , Embarazo , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/complicaciones , Metionina , Sulfonas , Lípidos
7.
BMC Microbiol ; 23(1): 4, 2023 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-36604616

RESUMEN

BACKGROUND: Human immunodeficiency virus (HIV) severely damages the epithelial cells of the gut lining leading to an inflamed leaky gut, translocation of microbial products, and dysbiosis resulting in systemic immune activation. Also, microbiota composition and maternal gut function can be altered in pregnancy through changes in the immune system and intestinal physiology. The aim of this study was to investigate the gut microbiota in HIV-infected and HIV-uninfected pregnant women and to compare and identify the association between gut microbial composition and adverse birth outcomes. RESULTS: A total of 94 pregnant women (35 HIV-infected and 59 HIV-uninfected controls) were recruited in Harare from 4 polyclinics serving populations with relatively poor socioeconomic status. Women were of a median age of 28 years (interquartile range, IQR: 22.3-32.0) and 55% of women were 35 weeks gestational age at enrolment (median 35.0 weeks, IQR: 32.5-37.2). Microbiota profiling in these participants showed that species richness was significantly lower in the HIV-infected pregnant women compared to their HIV-uninfected peers and significant differences in ß-diversity using Bray-Curtis dissimilarity were observed. In contrast, there was no significant difference in α-diversity between immune-compromised (CD4+ < 350 cells/µL) and immune-competent HIV-infected women (CD4+ ≥ 350 cells/µL) even after stratification by viral load suppression. HIV infection was significantly associated with a reduced abundance of Clostridium, Turicibacter, Ruminococcus, Parabacteroides, Bacteroides, Bifidobacterium, Treponema, Oscillospira, and Faecalibacterium and a higher abundance of Actinomyces, and Succinivibrio. Low infant birth weight (< 2500 g) was significantly associated with high abundances of the phylum Spirochaetes, the families Spirochaeteceae, Veillonellaceae, and the genus Treponema. CONCLUSION: The results reported here show that the species richness and taxonomy composition of the gut microbiota is altered in HIV-infected pregnant women, possibly reflecting intestinal dysbiosis. Some of these taxa were also associated with low infant birth weight.


Asunto(s)
Microbioma Gastrointestinal , Infecciones por VIH , Lactante , Embarazo , Humanos , Femenino , VIH , Resultado del Embarazo , Infecciones por VIH/microbiología , Peso al Nacer , Disbiosis , Configuración de Recursos Limitados , Zimbabwe
8.
Virol J ; 18(1): 30, 2021 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-33514390

RESUMEN

INTRODUCTION: Despite being a leading infectious cause of childhood disability globally, testing for cytomegalovirus (CMV) infections in pregnancy is generally not done in Sub-Sahara Africa (SSA), where breastfeeding practice is almost universal. Whilst CMV and human immunodeficiency virus (HIV) are both endemic in SSA, the relationship between antenatal plasma CMV-DNA, HIV-1-RNA levels and HIV-1-mother to child transmission (MTCT) including pregnancy outcomes remains poorly described. METHODS: Pregnant women at least 20 weeks' gestational age at enrolment were recruited from relatively poor high-density suburbs in Harare, Zimbabwe. Mother-infant dyads were followed up until 6 months postpartum. In a case-control study design, we tested antenatal plasma CMV-DNA levels in all 11 HIV-1 transmitting mothers, as well as randomly selected HIV-infected but non-transmitting mothers and HIV-uninfected controls. CMV-DNA was detected and quantified using polymerase chain reaction (PCR) technique. Antenatal plasma HIV-1-RNA load was quantified by reverse transcriptase PCR. Infants' HIV-1 infection was detected using qualitative proviral DNA-PCR. Predictive value of antenatal plasma CMV-DNAemia (CMV-DNA of > 50 copies/mL) for HIV-1-MTCT was analyzed in univariate and multivariate regression analyses. Associations of CMV-DNAemia with HIV-1-RNA levels and pregnancy outcomes were also explored. RESULTS: CMV-DNAemia data were available for 11 HIV-1 transmitting mothers, 120 HIV-infected but non-transmitting controls and 46 HIV-uninfected mothers. In a multivariate logistic regression model, we found a significant association between CMV-DNAemia of > 50 copies/mL and HIV-1 vertical transmission (p = 0.035). There was no difference in frequencies of detectable CMV-DNAemia between HIV-infected and -uninfected pregnant women (p = 0.841). However, CMV-DNA levels were higher in immunosuppressed HIV-infected pregnant women, CD4 < 200 cells/µL (p = 0.018). Non-significant associations of more preterm births (< 37 weeks, p = 0.063), and generally lower birth weights (< 2500 g, p = 0.450) were observed in infants born of HIV-infected mothers with CMV-DNAemia. Furthermore, in a multivariate analysis of HIV-infected but non-transmitting mothers, CMV-DNAemia of > 50 copies/mL correlated significantly with antenatal plasma HIV-1-RNA load (p = 0.002). CONCLUSION: Antenatal plasma CMV-DNA of > 50 copies/mL may be an independent risk factor for HIV-1-MTCT and higher plasma HIV-1-RNA load, raising the possibility that controlling antenatal CMV-DNAemia might improve infant health outcomes. Further studies with larger sample sizes are warranted to confirm our findings.


Asunto(s)
Infecciones por Citomegalovirus/sangre , Citomegalovirus/genética , ADN Viral/sangre , Infecciones por VIH/transmisión , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Adolescente , Adulto , Estudios de Casos y Controles , Estudios de Cohortes , Femenino , VIH-1/genética , Humanos , Lactante , Recién Nacido , Madres , Embarazo , Complicaciones Infecciosas del Embarazo/virología , Resultado del Embarazo , Diagnóstico Prenatal/estadística & datos numéricos , Adulto Joven , Zimbabwe
9.
BMC Infect Dis ; 20(1): 725, 2020 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-33008316

RESUMEN

BACKGROUND: Commencing lifelong antiretroviral therapy (ART) immediately following HIV diagnosis (Option B+), has greatly improved maternal-infant health. Thus, large and increasing numbers of HIV-infected women are on ART during pregnancy, a situation concurrently increasing numbers of HIV-exposed-uninfected (HEU) infants. Compared to their HIV-unexposed-uninfected (HUU) counterparts, HEU infants show higher rates of adverse birth outcomes, mortality, infectious/non-communicable diseases including impaired growth and neurocognitive development. There is an urgent need to understand the impact of HIV and early life ART exposures, immune-metabolic dysregulation, comorbidities and environmental confounders on adverse paediatric outcomes. METHODS: Six hundred (600) HIV-infected and 600 HIV-uninfected pregnant women ≥20 weeks of gestation will be enrolled from four primary health centres in high density residential areas of Harare. Participants will be followed up as mother-infant-pairs at delivery, week(s) 1, 6, 10, 14, 24, 36, 48, 72 and 96 after birth. Clinical, socio-economic, nutritional and environmental data will be assessed for adverse birth outcomes, impaired growth, immune/neurodevelopment, vertical transmission of HIV, hepatitis-B/C viruses, cytomegalovirus and syphilis. Maternal urine, stool, plasma, cord blood, amniotic fluid, placenta and milk including infant plasma, dried blood spot and stool will be collected at enrolment and follow-up visits. The composite primary endpoint is stillbirth and infant mortality within the first two years of life in HEU versus HUU infants. Maternal mortality in HIV-infected versus -uninfected women is another primary outcome. Secondary endpoints include a range of maternal and infant outcomes. Sub-studies will address maternal stress and malnutrition, maternal-infant latent tuberculosis, Helicobacter pylori infections, immune-metabolomic dysregulation including gut, breast milk and amniotic fluid dysbiosis. DISCUSSION: The University of Zimbabwe-College of Health-Sciences-Birth-Cohort study will provide a comprehensive assessment of risk factors and biomarkers for HEU infants' adverse outcomes. This will ultimately help developing strategies to mitigate effects of maternal HIV, early-life ART exposures and comorbidities on infants' mortality and morbidity. TRIAL REGISTRATION: ClinicalTrial.gov Identifier: NCT04087239 . Registered 12 September 2019.


Asunto(s)
Transmisión Vertical de Enfermedad Infecciosa , Estudios de Cohortes , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por Helicobacter/complicaciones , Helicobacter pylori , Hepatitis B/complicaciones , Humanos , Lactante , Mortalidad Infantil , Leche Humana , Morbilidad , Parto , Embarazo , Complicaciones Infecciosas del Embarazo/virología , Factores de Riesgo , Mortinato , Sífilis/complicaciones , Universidades , Zimbabwe
10.
J Microbiol Immunol Infect ; 53(4): 612-621, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30583941

RESUMEN

BACKGROUND: Asymptomatic Entamoeba histolytica infections in pregnant women puts infants at risk of infection through vertical transmission or transmission during breastfeeding in high HIV prevalence areas. The study aimed at investigating the immune response to asymptomatic E.histolytica infection in pregnant women and their infants in a high HIV burdened setting in Harare, Zimbabwe. METHODOLOGY: Serum samples from 39 predominantly breastfeeding mother-infant pairs were analyzed for inflammatory cytokine and immunoglobulin profiles using BIOPLEX. The infants' ages ranged from 10 days to 14 weeks. RESULTS: IL-1r, IL-4, IL-9, IL-12p70, IL-17a, G-CSF and PDGF-BB were significantly raised in E. histolytica infected compared to non-infected lactating mothers (p < 0.05). Carriage of any form of enteric infection such as Non-lactose fermenters (NLFs) including E. histolytica significantly increased concentration levels of IL-1r, IL-4, IL-9, IL-10, IL-12p70, IL17a, G-CSF, GM-CSF, IFN-γ, PDGF-BB and TNF-α cytokines (p < 0.05) but no significant differences in immunoglobulin levels among the mothers. Anti-inflammatory cytokines (IL-1r, IL-2, IL-4, IL-5, IL-6), pro-inflammatory cytokines (IL-9, IL-12-p70, IL-15, IL-17a, TNF-α) and growth factors (FGF-ß, G-CSF, GM-CSF, PDGF-bb) were significantly raised in HIV-uninfected mothers and not HIV-infected mothers during E. histolytica infection (p < 0.05). In infants, E. histolytica carriage and HIV exposure had no significant impact on the cytokine and immunoglobulin concentrations. CONCLUSION: Pro-inflammatory cytokines and chemokines are highly raised in lactating mothers with asymptomatic enteric pathogens hence there is need to check cytokine profiles in pregnant women and their infants to assist in decision making linked to treatment and prevention in times of pandemics.


Asunto(s)
Infecciones Asintomáticas/epidemiología , Citocinas/sangre , Entamoeba histolytica/inmunología , Entamebiasis/epidemiología , Entamebiasis/inmunología , Infecciones por VIH/epidemiología , Anticuerpos Antiprotozoarios/sangre , Bacterias/clasificación , Bacterias/inmunología , Bacterias/patogenicidad , Infecciones Bacterianas/epidemiología , Infecciones Bacterianas/inmunología , Lactancia Materna/estadística & datos numéricos , Estudios de Cohortes , Citocinas/inmunología , Entamoeba histolytica/patogenicidad , Femenino , Humanos , Lactante , Recién Nacido , Madres/estadística & datos numéricos , Embarazo , Mujeres Embarazadas , Adulto Joven , Zimbabwe/epidemiología
11.
Viral Immunol ; 32(7): 289-295, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31347990

RESUMEN

This study aimed to investigate the seroprevalence of cytomegalovirus (CMV) infection and risk factors associated with CMV acquisition among pregnant women in Zimbabwe. In a cross-sectional study, pregnant women were recruited in late gestation, seeking antenatal care at council clinics in three high-density suburbs in Harare, Zimbabwe. Anti-CMV IgM and IgG antibodies were quantified in serum using an enzyme-linked immunosorbent assay. Antibody avidity tests were used to distinguish active infection from viral reactivation in anti-CMV IgM-positive cases. Five hundred and twenty four women were recruited: 278 HIV infected and 246 HIV uninfected. Current or active CMV infection defined as IgM positive+low avidity was detected in 4.6% (24/524), 95% confidence interval (CI): 3-6.9 in all women, 5.8% (16/278) in the HIV infected and 3.3% (8/246), 95% CI: 1.4-6.3 in the HIV uninfected. IgG seroprevalence was 99.6% (522/524), 95% CI: 98.6-99.9 in all women. Notably, the difference in the prevalence of active CMV infection between the HIV-infected and HIV-uninfected women was not statistically significant (p = 0.173). The study shows a low prevalence of primary or active CMV infection among the pregnant women, but the IgG seroprevalence suggests high previous CMV exposure. Importantly, CMV seroprevalence was not associated with the HIV status of the women, perhaps due to the ubiquitous exposure of the population to CMV.


Asunto(s)
Infecciones por Citomegalovirus/epidemiología , Citomegalovirus/aislamiento & purificación , Infecciones por VIH/epidemiología , Complicaciones Infecciosas del Embarazo/epidemiología , Atención Prenatal/estadística & datos numéricos , Adulto , Anticuerpos Antivirales/sangre , Coinfección/sangre , Coinfección/epidemiología , Coinfección/virología , Estudios Transversales , Citomegalovirus/inmunología , Infecciones por Citomegalovirus/sangre , Infecciones por Citomegalovirus/virología , Femenino , Infecciones por VIH/sangre , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Embarazo , Complicaciones Infecciosas del Embarazo/sangre , Complicaciones Infecciosas del Embarazo/virología , Estudios Seroepidemiológicos , Adulto Joven , Zimbabwe/epidemiología
12.
BMC Pregnancy Childbirth ; 19(1): 218, 2019 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-31253114

RESUMEN

BACKGROUND: The importance of vitamin D in bone health and calcium homeostasis has been well documented. However, emerging evidence supports the role of vitamin D beyond its recognised traditional roles. In pregnancy, vitamin D levels are crucial in sustaining both the maternal stores and optimal growth of the foetus. In Southern Africa, there is paucity of data on vitamin D in pregnancy and related outcomes. To expand this body of knowledge, we assessed vitamin D levels in late pregnancy and (if any) associated maternal determinants in Harare, Zimbabwe. METHODS: Study participants comprised of 138 pregnant Zimbabwean women in their third trimester. These were stratified by HIV status; sampling median (IQR) gestation for HIV negative study participants was 34 weeks (26-41) and 31 weeks (20-40) in the HIV positive participants. Maternal plasma 25 hydroxyvitamin (OH) Dlevels were measured using the ClinPrepHigh Pressure Liquid Chromatography (HPLC) kit. Statistical analysis was carried out using the STATA statistical package version 13. A p-value of < 0.05was considered to be statistically significant. RESULTS: HIV infected participants had significantly higher mean 25 (OH) D concentration (112 ± 33.4 nmol/L) compared to the HIV uninfected (100 ± 27.1 nmol/L), p = 0.032.Participants whose samples were collected during summer had higher maternal 25 (OH) D levels than those cART duration and maternal 25 (OH) D levels (p = 0.031, Spearman correlation =0.28). CONCLUSIONS: Our findings show high mean levels of maternal 25 (OH) D in late pregnancy in our setting and in the absence of vitamin D supplementation. Both HIV infection and season are significant determinants of maternal vitamin D levels. Summer season is associated with higher maternal plasma 25 (OH) D levels. HIV infection is associated with increased maternal vitamin D levels. Prolonged use of cART, Tenolam E is associated with improved maternal 25(OH) D levels.


Asunto(s)
Infecciones por VIH/sangre , Complicaciones del Embarazo/epidemiología , Tercer Trimestre del Embarazo/sangre , Deficiencia de Vitamina D/epidemiología , Vitamina D/análogos & derivados , Adulto , Estudios Transversales , Suplementos Dietéticos/estadística & datos numéricos , Femenino , Infecciones por VIH/complicaciones , Humanos , Embarazo , Complicaciones del Embarazo/sangre , Complicaciones del Embarazo/virología , Factores de Riesgo , Estaciones del Año , Estadísticas no Paramétricas , Vitamina D/sangre , Vitamina D/uso terapéutico , Deficiencia de Vitamina D/sangre , Deficiencia de Vitamina D/virología , Vitaminas/uso terapéutico , Zimbabwe/epidemiología
13.
OMICS ; 23(2): 111-118, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30614763

RESUMEN

Past studies on the relationship between Killer cell Immunoglobulin-like Receptor (KIR) and Human Leukocyte Antigen (HLA) genetic variation and chronic immune activation (CIA) in HIV infection are not uniformly consistent. Moreover, interferon-γ-induced protein 10 (IP-10) is a soluble biomarker of immune activation, with high plasma concentrations predicting accelerated disease progression in HIV infection. Thus, we investigated the association of KIR and HLA-C genetic polymorphisms with plasma IP-10 concentration in 183 treatment-naive chronically HIV-infected adults of Bantu origin from Zimbabwe. KIR genetic variation was determined using allele-specific primer PCR while HLA-C typing was characterized by sequencing. Plasma IP-10 was quantified using enzyme-linked immunosorbent assay. The KIR2DL3 gene was significantly associated with CIA as observed from IP-10 concentrations among KIR2DL3 carriers (265.20 pg/mL, IQR: 179.99-385.19) compared with KIR2DL3 noncarriers (183.56 pg/mL; IQR: 110.98-230.81; p = 0.001) and among KIR2DL3+HLA-C2 carriers (226.23 pg/mL, IQR: 187.96-394.73) compared with KIR2DL3+HLA-C2 noncarriers (212.86 pg/mL, IQR: 160.15-344.99; p = 0.017), respectively. Similarly, IP-10 concentrations were significantly higher (p = 0.030) in the KIR3DS1 carriers (313.86 pg/mL, IQR: 230.05-469.20) compared with KIR3DS1 noncarriers (246.01 pg/mL, IQR: 169.58-373.32). Thus, KIR and HLA-C could be playing important roles in HIV-associated immune activation. The elevation of IP-10 in KIR2DL3 and KIR2DL3+C2 could potentially be explained by increased IFN-γ secretion from activated NK cell activation due to the absence of KIR2DL3's cognate C1 ligand. To the best of our knowledge, this is the first study on a potential link between KIR and HLA-C genetic determinants and plasma IP-10 concentration in this population sample. Future studies are called for in other world populations for biomarkers of disease progression and mechanisms of IP-10 variability in HIV infection.


Asunto(s)
Antirretrovirales/uso terapéutico , Quimiocina CXCL10/sangre , Antígenos HLA-C/genética , Polimorfismo Genético/genética , Receptores KIR/genética , Adulto , Alelos , Biomarcadores/sangre , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Infecciones por VIH , Humanos , Células Asesinas Naturales/metabolismo , Masculino , Zimbabwe
14.
Afr J Reprod Health ; 22(3): 43-50, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30381931

RESUMEN

This study aimed at investigating the maternal characteristics that in turn influence the immunological status of infants in asymptomatic enteric pathogen carriers in mother baby pairs (MBPs) in a high HIV burdened population in Harare, Zimbabwe. BIOPLEX immunoassay was used to analyse serum samples from 39 MBPs for 27 cytokines and 6 immunoglobulins. The MBP were purposively selected based on HIV infection and Entamoeba histolytica carriage. Logistic regression was used to identify any link between maternal demographic and clinical data with infant cytokine and immunoglobulin levels. Maternal E. histolytica carriers were more likely to have infants with low levels of IL-12p70, FGF-basic, GM-CSF and TNF-α cytokines (OR: 0.14; 95% CI: 0.03-0.79) and high levels of IgA immunoglobulin (OR: 8.1; 95% CI: 1.45-45.06). HIV infected mothers were more likely to have infants with low levels of IgG2 (OR: 0.24; 95% CI: 0.06-1.00) and IgA (OR: 0.22; 95% CI: 0.05-0.90) immunoglobulins. Notably, it was highly likely to deliver infants with low IgG4 levels (OR: 0.24; 95% CI: 0.06-1.02) for maternal mean age above 30.38 years (Standard deviation 6.09) though not significant (p=0.05). Maternal E. histolytica asymptomatic carriage, and HIV-infection status result in low levels of pro-inflammatory cytokines IL-12p70, FGF-basic, GM-CSF and TNF-α and immunoglobulins IgG2, IgG4 and IgA on their infants.


Asunto(s)
Citocinas/inmunología , Sangre Fetal/inmunología , Infecciones por VIH/inmunología , Inmunoglobulinas/sangre , Recién Nacido/inmunología , Transmisión Vertical de Enfermedad Infecciosa/estadística & datos numéricos , Complicaciones del Embarazo/inmunología , Adulto , Citocinas/sangre , Femenino , Infecciones por VIH/epidemiología , Infecciones por VIH/transmisión , Infecciones por VIH/virología , Humanos , Lactante , Recién Nacido/sangre , Madres , Embarazo , Complicaciones del Embarazo/virología , Complicaciones Infecciosas del Embarazo/epidemiología , Zimbabwe/epidemiología
15.
Papillomavirus Res ; 5: 180-191, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29723682

RESUMEN

Human papillomaviruses (HPVs) co-evolve slowly with the human host and each HPV genotype displays epithelial tropisms. We assessed the evolution of intra HPV genotype variants within samples, and their association to anogenital site, cervical cytology and HIV status. Variability in the L1 gene of 35 HPV genotypes was characterized phylogenetically using maximum likelihood, and portrayed by phenotype. Up to a thousand unique variants were identified within individual samples. In-depth analyses of the most prevalent genotypes, HPV16, HPV18 and HPV52, revealed that the high diversity was dominated by a few abundant variants. This suggests high intra-host mutation rates. Clades of HPV16, HPV18 and HPV52 were associated to anatomical site and HIV co-infection. Particularly, we observed that one HPV16 clade was specific to vaginal cells and one HPV52 clade was specific to anal cells. One major HPV52 clade, present in several samples, was strongly associated with cervical neoplasia. Overall, our data suggest that tissue tropism and HIV immunosuppression are strong shapers of HPV evolution.


Asunto(s)
Alphapapillomavirus/genética , Variación Genética , Tropismo Viral/genética , Adulto , Alphapapillomavirus/clasificación , Canal Anal/citología , Canal Anal/virología , Proteínas de la Cápside/genética , Cuello del Útero/citología , Cuello del Útero/virología , Coinfección/virología , Evolución Molecular , Femenino , Genotipo , Infecciones por VIH/complicaciones , Humanos , Mutación , Proteínas Oncogénicas Virales/genética , Infecciones por Papillomavirus/virología , Filogenia , Vagina/citología , Vagina/virología , Adulto Joven
16.
J Infect Dev Ctries ; 12(12): 1105-1111, 2018 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-32027612

RESUMEN

INTRODUCTION: Polymorphisms in killer cell immunoglobulin-like receptor (KIR) and human leukocyte antigen (HLA) gene families are implicated in differential outcomes of HIV infection. However, research findings on the influence of KIR and HLA-C polymorphism on HIV disease progression remain inconclusive. We thus investigated the association of KIR and HLA-C gene polymorphisms with plasma HIV load (VL) and CD4+ T lymphocyte (CD4) count in 183 chronically HIV-infected, combination antiretroviral therapy (cART) naïve Zimbabweans of Bantu origin. METHODOLOGY: The presence or absence of 15 KIR genes were determined using sequence specific primer polymerase chain reaction while HLA-C typing was performed using chain termination DNA sequencing. Plasma VL was determined using the Cavidi Exavir viral load version 3 assay while CD4+ T lymphocytes were enumerated using flow cytometry. VLs and CD4 counts were compared between gene/genotype carriers and non-carriers using Mann-Whitney ranksum test. RESULTS: HLA-C*18:01 allele carriers had a significantly lower median log10 VL (2.87copies/mL [IQR;2.3-3.2]) than the non-C*18:01 carriers (3.33copies/mL [IQR; 2.74-3.9]), p = 0.018. Further, median log10 VL was significantly lower in KIR2DL2+C1 carriers (2.745 [IQR; 2.590-2.745]) than non-KIR2DL2+C1 carriers (3.4 [IQR; 2.746-3.412]), p = 0.041. Comparison of CD4 + T lymphocyte counts between C*08:02 allele carriers and non-C*08:02 carriers showed a significantly higher median CD4 count in C*08:02 carriers (548cells/µL [IQR;410-684]) than in non-carriers (428cells/µL [IQR;388-537]), p = 0.034. CONCLUSION: We conclude that the HLA-C*18:01 and KIR2DL2+C1 genetic variants are associated with low VL while the C*08:02 is associated with high CD4+ T lymphocyte count among cART naïve Zimbabwean adults with chronic HIV infection.


Asunto(s)
Infecciones por VIH/genética , Infecciones por VIH/virología , Antígenos HLA-C/genética , Receptores KIR2DL2/genética , Adulto , Terapia Antirretroviral Altamente Activa , Linfocitos T CD4-Positivos/fisiología , Linfocitos T CD4-Positivos/virología , Estudios Transversales , Frecuencia de los Genes , Infecciones por VIH/tratamiento farmacológico , Humanos , Polimorfismo Genético , Carga Viral , Zimbabwe
17.
Open Microbiol J ; 11: 45-52, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28553415

RESUMEN

BACKGROUND: Antiretroviral therapy (ART) to suppress HIV replication has reduced morbidity and mortality yet effectiveness of current HIV drugs is threatened by HIV drug resistance (HIVDR) mutations. OBJECTIVE: To determine HIVDR mutations using proviral DNA from specimens of patients presenting to an HIV treatment clinic. METHODS: DNA from 103 patients, 86 treatment-experienced, 17 treatment-naïve, were genotyped for the HIV-1C reverse transcriptase gene (RT; codons 21-304) using Sanger sequencing and sequences analyzed using Sequencher software. Resistance mutations were interpreted using Stanford HIVDR reference database. RESULTS: Median age was 39 (IQR, 33-46) years and 80% of patients were female. Six-percent (n=6) had at least one HIVDR mutation, comprising NRTI-associated mutations, (M184V, T69D, T69N and V75I); NNRTI-associated mutations (G190A, K103N, V106M, Y181C) and thymidine analogue associated mutations (D67N, K70R, K219Q, L210W, M41L, T215Y). Of the six participants, with at least one HIVDR mutation, all were treatment experienced, five were on tenofovir, lamivudine and nevirapine and one was on tenofovir, lamivudine and atazanavir. There was no difference in median CD4 count and viral loads when patients were compared by presence of HIVDR mutations. CONCLUSION: We demonstrated the use of proviral DNA in HIVDR testing in adult patients and present that all the patients with various kinds of HIVDR mutations were treatment experienced, pointing to the role of drug regimens in driving viral mutations. Thus, the use of proviral DNA has potential to help provide surveillance on risk of HIVDR in HIV-infected individuals who are on treatment, which may assist in corrective treatment.

18.
Open AIDS J ; 11: 24-31, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28553429

RESUMEN

BACKGROUND: Chronic immune activation is a feature of HIV infection associated with accelerated HIV disease progression. There is conflicting data on the association of biomarkers of immune activation with traditional markers of HIV disease progression; CD4 counts and viral load (VL). OBJECTIVE: The study aimed to determine the association of biomarkers of immune activation; interferon (IFN)-γ-induced protein 10 (IP-10) and soluble cluster of differentiation 14 (sCD14) in chronic HIV infection with traditional markers of HIV disease progression. METHODS: We collected demographic data, enumerated CD4 counts and quantified VL in 183 antiretroviral therapy (ART)-naive adults with chronic HIV infection. Plasma concentrations of IP-10 and sCD14 were quantified in the ART-naive adults with chronic HIV infection and 75 HIV-uninfected controls. RESULTS: IP-10 concentrations were significantly higher in the HIV-infected group (median; 257.40pg/ml, IQR; 174.08-376.32) than in the HIV-uninfected (median; 86.19pg/ml, IQR; 67.70-116.39) (P<0.001). Similarly, sCD14 concentrations were significantly higher in the HIV-infected (median; 1.45µg/ml, IQR; 1.02-2.16) group than in the controls (median; 0.89µ/ml, IQR; 0.74-1.18) (P<0.001). High log10 IP-10 concentrations were positively correlated with high log10 viral loads (Spearman's correlation coefficient [R]=0.21, P=0.003) and inversely correlated with low CD4 counts (R= -0.19, P=0.011). In contrast, log10 sCD14 was not significantly associated with either log10 viral loads (R=0.03, P=0.707) nor CD4 count (R=-0.04, P=0.568). CONCLUSION: We conclude that plasma sCD14 and IP-10 were elevated in the HIV-infected patients compared to HIV-uninfected individuals possibly due to on-going immune activation. In addition, plasma high concentrations of IP-10 but not sCD14 concentrations are associated with high VL and low CD4 count.

19.
J Med Virol ; 89(9): 1671-1677, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28390142

RESUMEN

Although anogenital cancers have been on a gradual rise in developing countries in the past few decades, they have been understudied. The objective was to investigate genotypic diversity of anogenital HPV amongst women reporting for routine cervical cancer screening in Harare in Zimbabwe. A cross-sectional study that enrolled 144 women ≥18 years from a cervical cancer-screening clinic was performed. Each woman provided a self-collected cervico-vaginal swab (VS) and a clinician-collected anal swab (CCAS). HIV testing was offered and cervical cytology was performed. Both VS and CCAS samples were HPV genotyped, using amplicon sequencing of the L1 gene region with Illumina technology. Mean age of the women was 39.9 (range 18-83 years, SD ± 11.0). HPV prevalence was 72% (104/144) in VS and 48% (69/144) in CCAS. The most common genotypes detected in both VS and CCAS were HPV18, HPV52, and HPV16. Sixty two percent of the subjects had multiple genotypic HPV infections. The odds of being HPV-positive among HIV-infected women were higher than in HIV-negative women in both the vagina and the anus (CCAS OR = 4.8; CI 2.4-9.8, P < 0.001) and (VS OR = 2.9; CI 1.3-6.4, P = 0.005). High HPV prevalence and diverse genotypes were detected in both the vagina and anus. Anal oncogenic HPV infection was common. HPV 52 was one of the most common oncogenic genotypes in both the vagina and anus. HIV co-infection played a significant role in the prevalence of HPV. These data have implications for design of primary and secondary programs for prevention of anogenital cancer in Zimbabwe.


Asunto(s)
Variación Genética , Genotipo , Papillomaviridae/clasificación , Papillomaviridae/genética , Infecciones por Papillomavirus/virología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Canal Anal/virología , Proteínas de la Cápside/genética , Estudios Transversales , Detección Precoz del Cáncer , Estudios Epidemiológicos , Femenino , Genitales Femeninos/virología , Técnicas de Genotipaje , Humanos , Persona de Mediana Edad , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/epidemiología , Análisis de Secuencia de ADN , Neoplasias del Cuello Uterino/diagnóstico , Adulto Joven , Zimbabwe/epidemiología
20.
OMICS ; 20(12): 727-735, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27930093

RESUMEN

Killer cell immunoglobulin-like receptors (KIRs) mediate natural killer cell function through interaction with their cognate human leukocyte antigen ligands. Thus, KIR gene variants have been implicated in resistance or susceptibility to viral infections. However, research on the role of these variants remains contradictory and inconclusive. In the present study, we investigated KIR gene content diversity and its association with human immunodeficiency virus (HIV) infection in an adult Black Zimbabwean population. Presence or absence of 15 KIR genes was determined in 189 HIV-infected adults and 97 HIV-uninfected blood donors using sequence specific primer polymerase chain reaction. Frequencies of KIR genes, genotypes, and haplotypes were compared between the cases and controls to identify putative associations between KIR gene variants and HIV status. We report in this study the frequencies of 15 KIR genes and 43 KIR genotypes (40 known and 3 novel) among Zimbabweans. Importantly, the frequency of the inhibitory KIR2DL2 gene was significantly higher in the uninfected group (62%) compared to the HIV-infected group (47%) (OR = 0.55, 95% CI: 0.33-0.90, p = 0.019). KIR2DL2/2DL2 homozygosity was also significantly higher in the uninfected group (35%) compared to HIV-infected group (53%) (OR = 0.33, 95% CI: 0.16-0.72, p = 0.005) under a recessive model. We conclude that the KIR2DL2 gene may be involved in protection against HIV infection. It may be possible that inhibitory KIR genes may have an important role to play in HIV acquisition among populations of African origin in whom the activating KIR genes are less frequent compared to among Caucasians.


Asunto(s)
Predisposición Genética a la Enfermedad/genética , Infecciones por VIH/genética , Adulto , Femenino , Frecuencia de los Genes/genética , Genotipo , Haplotipos/genética , Humanos , Masculino , Receptores KIR/genética , Zimbabwe
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...