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1.
J Pharmacol Exp Ther ; 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38955493

RESUMEN

Secondary spinal cord injury (SCI) is characterized by increased cytokines and chemokines at the site of injury that have been associated with the development of neuropathic pain. Nearly 80% of SCI patients report suffering from chronic pain, which is poorly managed with available analgesics. While treatment with the FDA-approved ß2-adrenergic receptor agonist, formoterol, improves various aspects of recovery post-SCI in vivo, its effects on cytokines, chemokines and neuropathic pain remain unknown. Female mice were subjected to moderate (60 kdyn) or severe (80 kdyn) SCI followed by daily treatment with vehicle or formoterol (0.3 mg/kg, i.p.) beginning 8h after injury. The expression of pro-inflammatory cytokines/chemokines, such as IP-10, MIP-1a, MCP-1, BCA-1 and NF-κB, was increased in the injury site of vehicle-treated mice 24h post-SCI, which was ameliorated with formoterol treatment, regardless of injury severity. Thermal hyperalgesia and mechanical allodynia, as measured by Hargreaves infrared apparatus and von Frey filaments, respectively, were assessed prior to SCI and then weekly beginning 21 days post injury (DPI). While all injured mice exhibited decreased withdrawal latency following thermal stimulation compared to baseline, formoterol treatment reduced this response ~15% by 35 DPI. Vehicle-treated mice displayed significant mechanical allodynia, as evidenced by a 55% decrease in withdrawal threshold from baseline. In contrast, mice treated with formoterol maintained a consistent withdrawal time at all times tested. These data indicate that formoterol reduces inflammation post-SCI, likely contributing to mitigation of neuropathic pain, and further supporting the therapeutic potential of this treatment strategy. Significance Statement Chronic pain is a detrimental consequence of spinal cord injury (SCI). We show that treatment with the FDA-approved drug formoterol after SCI decreases injury site pro-inflammatory chemo/cytokines and alters markers of glial cell activation and infiltration. Additionally, formoterol treatment improves locomotor function and body composition, and decreases lesion volume. Finally, formoterol treatment decreased mechanical allodynia and thermal hyperalgesia post-SCI. These data are suggestive of the mechanism of formoterol-induced recovery, and further indicate its potential as a therapeutic strategy for SCI.

2.
J Infect Dis ; 225(2): 248-256, 2022 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-34216212

RESUMEN

BACKGROUND: Intermittent preventive treatment of malaria during pregnancy (IPTp) with dihydroartemisinin-piperaquine (DP) provides greater protection from placental malaria than sulfadoxine-pyrimethamine (SP). Some studies suggest placental malaria alters risk of malaria infection in infants, but few have quantified the effect of IPTp on infant susceptibility to malaria. METHODS: Infants born to women enrolled in a randomized clinical trial comparing IPTp-SP and IPTp-DP in Malawi were followed from birth to 24 months to assess effect of IPTp and placental malaria on time to first malaria episode and Plasmodium falciparum incidence. RESULTS: In total, 192 infants born to mothers randomized to IPTp-SP and 195 randomized to IPTp-DP were enrolled. Infants in IPTp exposure groups did not differ significantly regarding incidence of clinical malaria (incidence rate ratio [IRR], 1.03; 95% confidence interval [CI], .58-1.86) or incidence of infection (IRR, 1.18; 95% CI, .92-1.55). Placental malaria exposure was not associated with incidence of clinical malaria (IRR, 1.03; 95% CI, .66-1.59) or infection (IRR, 1.15; 95% CI, .88-1.50). Infant sex, season of birth, and maternal gravidity did not confound results. CONCLUSIONS: We did not find evidence that IPTp regimen or placental malaria exposure influenced risk of malaria during infancy in this population. Clinical Trials Registration. NCT03009526.


Asunto(s)
Antimaláricos/uso terapéutico , Artemisininas/uso terapéutico , Malaria/tratamiento farmacológico , Malaria/prevención & control , Parasitemia/prevención & control , Piperazinas/uso terapéutico , Complicaciones Parasitarias del Embarazo/tratamiento farmacológico , Complicaciones Parasitarias del Embarazo/prevención & control , Quinolinas/uso terapéutico , Adulto , Combinación de Medicamentos , Femenino , Humanos , Lactante , Malaria/epidemiología , Malaui/epidemiología , Placenta/parasitología , Embarazo , Complicaciones Parasitarias del Embarazo/epidemiología , Pirimetamina/uso terapéutico , Sulfadoxina/uso terapéutico , Resultado del Tratamiento
3.
J Infect Dis ; 226(1): 138-146, 2022 08 12.
Artículo en Inglés | MEDLINE | ID: mdl-35290461

RESUMEN

BACKGROUND: In areas highly endemic for malaria, Plasmodium falciparum infection prevalence peaks in school-age children, adversely affecting health and education. School-based intermittent preventive treatment reduces this burden but concerns about cost and widespread use of antimalarial drugs limit enthusiasm for this approach. School-based screening and treatment is an attractive alternative. In a prospective cohort study, we evaluated the impact of school-based screening and treatment on the prevalence of P. falciparum infection and anemia in 2 transmission settings. METHODS: We screened 704 students in 4 Malawian primary schools for P. falciparum infection using rapid diagnostic tests (RDTs), and treated students who tested positive with artemether-lumefantrine. We determined P. falciparum infection by microscopy and quantitative polymerase chain reaction (qPCR), and hemoglobin concentrations over 6 weeks in all students. RESULTS: Prevalence of infection by RDT screening was 37% (9%-64% among schools). An additional 9% of students had infections detected by qPCR. Following the intervention, significant reductions in infections were detected by microscopy (adjusted relative reduction [aRR], 48.8%; P < .0001) and qPCR (aRR, 24.5%; P < .0001), and in anemia prevalence (aRR, 30.8%; P = .003). Intervention impact was reduced by infections not detected by RDT and new infections following treatment. CONCLUSIONS: School-based screening and treatment reduced P. falciparum infection and anemia. This approach could be enhanced by repeating screening, using more-sensitive screening tests, and providing longer-acting drugs. CLINICAL TRIALS REGISTRATION: NCT04858087.


Asunto(s)
Anemia , Antimaláricos , Malaria Falciparum , Malaria , Anemia/diagnóstico , Anemia/epidemiología , Anemia/prevención & control , Antimaláricos/uso terapéutico , Arteméter , Combinación Arteméter y Lumefantrina/uso terapéutico , Niño , Humanos , Malaria/epidemiología , Malaria Falciparum/diagnóstico , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/epidemiología , Malaui/epidemiología , Plasmodium falciparum , Prevalencia , Estudios Prospectivos , Instituciones Académicas
4.
J Infect Dis ; 219(12): 1948-1958, 2019 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-30629187

RESUMEN

BACKGROUND: The contribution of immune activation to arterial stiffness and its reversibility in human immunodeficiency virus (HIV)-infected adults in sub-Saharan Africa is unknown. METHODS: HIV-uninfected and HIV-infected Malawian adults initiating antiretroviral therapy (ART) with a CD4+ T-cell count of <100 cells/µL were enrolled and followed for 44 weeks; enrollment of infected adults occurred 2 weeks after ART initiation. We evaluated the relationship between carotid femoral pulse wave velocity (cfPWV) and T-cell activation (defined as HLA-DR+CD38+ T cells), exhaustion (define as PD-1+ T cells), and senescence (defined as CD57+ T cells) and monocyte subsets, using normal regression. RESULTS: In 279 HIV-infected and 110 HIV-uninfected adults, 142 (37%) had hypertension. HIV was independently associated with a 12% higher cfPWV (P = .02) at baseline and a 14% higher cfPWV at week 10 (P = .02), but the increases resolved by week 22. CD4+ and CD8+ T-cell exhaustion were independently associated with a higher cfPWV at baseline (P = .02). At 44 weeks, arterial stiffness improved more in those with greater decreases in the percentage of CD8+ T cells and the percentage of PD-1+CD8+ T cells (P = .01 and P = .03, respectively). When considering HIV-infected participants alone, the adjusted arterial stiffness at week 44 tended to be lower in those with higher baseline percentage of PD-1+CD8+ T cells (P = .054). CONCLUSIONS: PD-1+CD8+ T-cells are associated with HIV-related arterial stiffness, which remains elevated during the first 3 months of ART. Resources to prevent cardiovascular disease in sub-Saharan Africa should focus on blood pressure reduction and individuals with a low CD4+ T-cell count during early ART.


Asunto(s)
Antirretrovirales/uso terapéutico , Linfocitos T CD8-positivos/metabolismo , Infecciones por VIH , Receptor de Muerte Celular Programada 1/metabolismo , Rigidez Vascular/efectos de los fármacos , Adulto , Antirretrovirales/farmacología , Linfocitos T CD8-positivos/citología , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/fisiopatología , Humanos , Malaui , Masculino
5.
J Infect Dis ; 214(11): 1700-1711, 2016 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-27630199

RESUMEN

BACKGROUND: We used data from 4 years of pediatric severe acute respiratory illness (SARI) sentinel surveillance in Blantyre, Malawi, to identify factors associated with clinical severity and coviral clustering. METHODS: From January 2011 to December 2014, 2363 children aged 3 months to 14 years presenting to the hospital with SARI were enrolled. Nasopharyngeal aspirates were tested for influenza virus and other respiratory viruses. We assessed risk factors for clinical severity and conducted clustering analysis to identify viral clusters in children with viral codetection. RESULTS: Hospital-attended influenza virus-positive SARI incidence was 2.0 cases per 10 000 children annually; it was highest among children aged <1 year (6.3 cases per 10 000), and human immunodeficiency virus (HIV)-infected children aged 5-9 years (6.0 cases per 10 000). A total of 605 SARI cases (26.8%) had warning signs, which were positively associated with HIV infection (adjusted risk ratio [aRR], 2.4; 95% confidence interval [CI], 1.4-3.9), respiratory syncytial virus infection (aRR, 1.9; 95% CI, 1.3-3.0) and rainy season (aRR, 2.4; 95% CI, 1.6-3.8). We identified 6 coviral clusters; 1 cluster was associated with SARI with warning signs. CONCLUSIONS: Influenza vaccination may benefit young children and HIV-infected children in this setting. Viral clustering may be associated with SARI severity; its assessment should be included in routine SARI surveillance.


Asunto(s)
Infecciones del Sistema Respiratorio/epidemiología , Virosis/epidemiología , Virus/clasificación , Virus/aislamiento & purificación , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Malaui/epidemiología , Masculino , Nasofaringe/virología
6.
BMC Pulm Med ; 15: 96, 2015 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-26286032

RESUMEN

BACKGROUND: Pneumonia is the 2nd leading cause of years of life lost worldwide and is a common cause of adult admissions to hospital in sub-Saharan Africa. Risk factors for adult pneumonia are well characterised in developed countries, but are less well described in sub-Saharan Africa where HIV is a major contributing factor. Exposure to indoor and outdoor air pollution is high, and tobacco smoking prevalence is increasing in sub-Saharan Africa, yet the contribution of these factors to the burden of chronic respiratory diseases in sub-Saharan Africa remains poorly understood. Furthermore, the extent to which the presence of chronic respiratory diseases and exposure to air pollution contribute to the burden of pneumonia is not known. DESIGN: The Acute Infection of the Respiratory Tract Study (The AIR Study) is a case-control study to identify preventable risk factors for adult pneumonia in the city of Blantyre, Malawi. Cases will be adults admitted with pneumonia, recruited from Queen Elizabeth Central Hospital, the largest teaching hospital in Malawi. Controls will be adults without pneumonia, recruited from the community. The AIR Study will recruit subjects and analyse data within strata defined by positive and negative HIV infection status. All participants will undergo thorough assessment for a range of potential preventable risk factors, with an emphasis on exposure to air pollution and the presence of chronic respiratory diseases. This will include collection of questionnaire data, clinical samples (blood, urine, sputum and breath samples), lung function data and air pollution monitoring in their home. Multivariate analysis will be used to identify the important risk factors contributing to the pneumonia burden in this setting. Identification of preventable risk factors will justify research into the effectiveness of targeted interventions to address this burden in the future. DISCUSSION: The AIR Study is the first study of radiologically confirmed pneumonia in which air pollution exposure measurements have been undertaken in this setting, and will contribute important new information about exposure to air pollution in urban SSA. Through identification of preventable risk factors, the AIR Study aims to facilitate future research and implementation of targeted interventions to reduce the high burden of pneumonia in SSA.


Asunto(s)
Contaminación del Aire/efectos adversos , Neumonía/epidemiología , Infecciones del Sistema Respiratorio/epidemiología , Enfermedad Aguda , Adulto , Femenino , Humanos , Incidencia , Malaui/epidemiología , Masculino , Neumonía/etiología , Prevalencia , Infecciones del Sistema Respiratorio/etiología , Factores de Riesgo , Tasa de Supervivencia/tendencias , Adulto Joven
7.
Front Neurosci ; 18: 1367473, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38435055

RESUMEN

Astrocytes are a widely heterogenic cell population that play major roles in central nervous system (CNS) homeostasis and neurotransmission, as well as in various neuropathologies, including spinal cord injury (SCI), traumatic brain injury, and neurodegenerative diseases, such as amyotrophic lateral sclerosis. Spinal cord astrocytes have distinct differences from those in the brain and accurate modeling of disease states is necessary for understanding disease progression and developing therapeutic interventions. Several limitations to modeling spinal cord astrocytes in vitro exist, including lack of commercially available adult-derived cells, lack of purchasable astrocytes with different genotypes, as well as time-consuming and costly in-house primary cell isolations that often result in low yield due to small tissue volume. To address these issues, we developed an efficient adult mouse spinal cord astrocyte isolation method that utilizes enzymatic digestion, debris filtration, and multiple ACSA-2 magnetic microbead purification cycles to achieve an astrocyte monoculture purity of ≅93-98%, based on all markers assessed. Importantly, the isolated cells contain active mitochondria and express key astrocyte markers including ACSA-1, ACSA-2, EAAT2, and GFAP. Furthermore, this isolation method can be applied to the spinal cord of male and female mice, mice subjected to SCI, and genetically modified mice. We present a primary adult mouse spinal cord astrocyte isolation protocol focused on purity, viability, and length of isolation that can be applied to a multitude of models and aid in targeted research on spinal-cord related CNS processes and pathologies.

8.
BMC Pediatr ; 12: 95, 2012 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-22770231

RESUMEN

BACKGROUND: There is little data on responses to combination antiretroviral therapy (cART) among HIV-infected children in the West African region. We describe treatment outcomes among HIV-1 and HIV-2 infected children initiating cART in a research clinic in The Gambia, West Africa. METHODS: All treatment naive HIV-infected children who initiated cART according to the WHO ART guidelines for children between October 2004 and December 2009 were included in the analysis. Kaplan-Meir estimates and sign-rank test were used to investigate the responses to treatment. RESULTS: 65 HIV-1 and five HIV-2 infected children aged < 15 years were initiated on cART over this time period. HIV-1 infected children were treated with a combination of Zidovudine or Stavudine + Lamivudine + Nevirapine or Efavirenz while children with HIV-2 were treated with Zidovudine + Lamivudine + ritonavir-boosted Lopinavir. HIV-1 infected children were followed-up for a median (IQR) duration of 20.1 months (6.9 - 34.3), with their median (IQR) age at treatment initiation, CD4% and plasma viral load at baseline found to be 4.9 years (2.1 - 9.1), 13.0% (7.0 - 16.0) and 5.4 log10 copies/ml (4.4 - 6.0) respectively. The median age at treatment initiation of the five HIV-2 infected children was 12 years (range: 4.6 - 14.0) while their median baseline CD4+ T cell count and HIV-2 viral load were 140 cells/mm3 (Range: 40 - 570 cells/mm3) and 4.5 log10copies/mL (Range: 3.1 - 4.9 log10copies/mL) respectively.Among HIV-1 infected children <5 years of age at ART initiation, the median (IQR) increases in CD4% from baseline to 12, 24 and 36 months were 14% (8 - 19; P = 0.0004), 21% (15 - 22; P = 0.005) and 15% (15 - 25; P = 0.0422) respectively, while the median (IQR) increase in absolute CD4 T cell count from baseline to 12, 24 and 36 months for those ≥5 years at ART initiation were 470 cells/mm3 (270 - 650; P = 0.0005), 230 cells/mm3 (30 - 610; P = 0.0196) and 615 cells/mm3 (250 - 1060; P = 0.0180) respectively. The proportions of children achieving undetectable HIV-1 viral load at 6-, 12-, 24- and 36 months of treatment were 24/38 (63.2%), 20/36 (55.6%), 8/22 (36.4%) and 7/12 (58.3%) respectively. The probability of survival among HIV-1 infected children after 12 months on ART was 89.9% (95% CI 78.8 - 95.3). CD4 T cell recovery was sub-optimal in all the HIV-2 infected children and none achieved virologic suppression. Two of the HIV-2 infected children died within 6 months of starting treatment while the remaining three were lost to follow-up. CONCLUSIONS: The beneficial effects of cART among HIV-1 infected children in our setting are sustained in the first 24 months of treatment with a significant improvement in survival experience up to 36 months; however the outcome was poor in the few HIV-2 infected children initiated on cART.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , VIH-1 , VIH-2 , Inhibidores de la Transcriptasa Inversa/uso terapéutico , Adolescente , Alquinos , Terapia Antirretroviral Altamente Activa , Benzoxazinas/uso terapéutico , Niño , Preescolar , Estudios de Cohortes , Ciclopropanos , Combinación de Medicamentos , Femenino , Estudios de Seguimiento , Gambia , Infecciones por VIH/mortalidad , Infecciones por VIH/virología , Humanos , Lactante , Estimación de Kaplan-Meier , Lamivudine/uso terapéutico , Lopinavir/uso terapéutico , Masculino , Nevirapina/uso terapéutico , Ritonavir/uso terapéutico , Resultado del Tratamiento , Carga Viral/estadística & datos numéricos , Zidovudina/uso terapéutico
9.
PLoS One ; 17(1): e0262797, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35045119

RESUMEN

BACKGROUND: In drug trials, adverse events (AEs) burden can induce treatment non-adherence or discontinuation. The non-adherence and discontinuation induce selection bias, affecting drug safety interpretation. Nested case-control (NCC) study can efficiently quantify the impact of the AEs, although choice of sampling approach is challenging. We investigated whether NCC study with incidence density sampling is more efficient than NCC with path sampling under conditional logistic or weighted Cox models in assessing the effect of AEs on treatment non-adherence and participation in preventive antimalarial drug during pregnancy trial. METHODS: Using data from a trial of medication to prevent malaria in pregnancy that randomized 600 women to receive chloroquine or sulfadoxine-pyrimethamine during pregnancy, we conducted a NCC study assessing the role of prospectively collected AEs, as exposure of interest, on treatment non-adherence and study non-completion. We compared estimates from NCC study with incidence density against those from NCC with path sampling under conditional logistic and weighted Cox models. RESULTS: Out of 599 women with the outcomes of interest, 474 (79%) experienced at least one AE before delivery. For conditional logistic model, the hazard ratio for the effect of AE occurrence on treatment non-adherence was 0.70 (95% CI: 0.42, 1.17; p = 0.175) under incidence density sampling and 0.68 (95% CI: 0.41, 1.13; p = 0.137) for path sampling. For study non-completion, the hazard ratio was 1.02 (95% CI: 0.56, 1.83; p = 0.955) under incidence density sampling and 0.85 (95% CI: 0.45, 1.60; p = 0.619) under path sampling. We obtained similar hazard ratios and standard errors under incidence density sampling and path sampling whether weighted Cox or conditional logistic models were used. CONCLUSION: NCC with incidence density sampling and NCC with path sampling are practically similar in efficiency whether conditional logistic or weighted Cox analytical methods although path sampling uses more unique controls to achieve the similar estimates. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01443130.


Asunto(s)
Malaria/tratamiento farmacológico , Cumplimiento de la Medicación/psicología , Antimaláricos/uso terapéutico , Estudios de Casos y Controles , Quimioprevención/métodos , Cloroquina/uso terapéutico , Análisis de Datos , Combinación de Medicamentos , Femenino , Humanos , Incidencia , Malaria/epidemiología , Modelos Teóricos , Embarazo , Complicaciones Parasitarias del Embarazo/epidemiología , Pirimetamina/uso terapéutico , Sulfadoxina/uso terapéutico
10.
Am J Trop Med Hyg ; 107(5): 1036-1040, 2022 11 14.
Artículo en Inglés | MEDLINE | ID: mdl-36252805

RESUMEN

Malaria in pregnancy (MIP) causes poor birth outcomes, but its impact on neurocognitive development has not been well characterized. Between 2012 and 2014, we enrolled 307 mother-infant pairs and monitored 286 infants for neurocognitive development using the Malawi Developmental Assessment Tool at 6, 12, and 24 months of age. MIP was diagnosed from peripheral blood and placental specimens. Cord blood cytokine levels were assessed for a subset of neonates. Predictors of neurodevelopment were examined using mixed-effect logistic regression for developmental delay. Among the participants, 78 mothers (25.4%) had MIP, and 45 infants (15.7%) experienced severe neurocognitive delay. MIP was not associated with differences in cord blood cytokine levels or neurocognitive development. Preterm birth, low birthweight, increasing maternal education level, and increasing interleukin 6 levels were associated significantly with delay. The results highlight the prevalence of severe delay and a need for broad access to early childhood support in this setting.


Asunto(s)
Malaria , Nacimiento Prematuro , Preescolar , Lactante , Recién Nacido , Embarazo , Femenino , Humanos , Placenta , Malaria/complicaciones , Malaria/epidemiología , Inflamación , Citocinas
11.
AIDS Res Ther ; 8(1): 24, 2011 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-21774813

RESUMEN

BACKGROUND: High early mortality rate among HIV infected patients following initiation of antiretroviral therapy (ART) in resource limited settings may indicate high pre-treatment mortality among ART-eligible patients. There is dearth of data on pre-treatment mortality in ART programmes in sub-Sahara Africa. This study aims to determine pre-treatment mortality rate and predictors of pre-treatment mortality among ART-eligible adult patients in a West Africa clinic-based cohort. METHODS: All HIV-infected patients aged 15 years or older eligible for ART between June 2004 and September 2009 were included in the analysis. Assessment for eligibility was based on the Gambia ART guideline. Survival following ART-eligibility was determined by Kaplan-Meier estimates and predictors of pre-treatment mortality determined by Cox proportional hazard models. RESULT: Overall, 790 patients were assessed as eligible for ART based on their clinical and/or immunological status among whom 510 (64.6%) started treatment, 26 (3.3%) requested transfer to another health facility, 136 (17.2%) and 118 (14.9%) were lost to follow-up and died respectively without starting ART. ART-eligible patients who died or were lost to follow-up were more likely to be male or to have a CD4 T-cell count < 100 cells/µL, while patients in WHO clinical stage 3 or 4 were more likely to die without starting treatment. The overall pre-treatment mortality rate was 21.9 deaths per 100 person-years (95% CI 18.3 - 26.2) and the rate for the composite end point of death or loss to follow-up was 47.1 per 100 person-years (95% CI 41.6 - 53.2). Independent predictors of pre-treatment mortality were CD4 T-cell count <100 cells/µL (adjusted Hazard ratio [AHR] 3.71; 95%CI 2.54 - 5.41) and WHO stage 3 or 4 disease (AHR 1.91; 95% CI 1.12 - 3.23). Forty percent of ART-eligible patients lost to follow-up seen alive at field visit cited difficulty with the requirement of disclosing their HIV status as reason for not starting ART. CONCLUSION: Approximately one third of ART-eligible patients did not start ART and pre-treatment mortality rate was found high among HIV infected patients in our cohort. CD4 T-cell count <100 cells/µL is the strongest independent predictor of pre-treatment mortality. The requirement to disclose HIV status as part of ART preparation counselling constitutes a huge barrier for eligible patients to access treatment.

12.
Am J Trop Med Hyg ; 104(6): 2123-2130, 2021 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-33939628

RESUMEN

In endemic settings where asymptomatic malaria infections are common, malaria infection can complicate fever diagnosis. Factors influencing fever misdiagnosis, including accuracy of malaria rapid diagnostic tests (mRDTs) and the malaria-attributable fraction of fevers (MAF), require further investigation. We conducted facility-based surveillance in Malawi, from January 2012 through December 2013 in settings of high perennial (Chikhwawa), high seasonal (Thoylo), and moderate seasonal (Ndirande) malaria transmission. Consecutive patients presenting to outpatient departments were screened; those with suspected malaria illness were tested by mRDT or routine thick-smear microscopy. Test positivity rates (TPRs), positive predictive value (PPVs) of mRDTs, and MAFs were calculated by site, age, and season. Of 41,471 patients, 10,052 (24.2%) tested positive for malaria. The TPR was significantly greater in Chikhwawa (29.9%; 95% CI, 28.6-30.0) compared with Thyolo (13.2%; 95% CI, 12.5-13.7) and Ndirande (13.1%; 95% CI, 12.2-14.4). The overall PPV was 77.8% (95% CI, 76.8-78.7); it was lowest among infants (69.9%; 95% CI, 65.5-74.2) and highest among school-age children (81.9%; 95% CI, 80.3-83.4). Malaria infection accounted for about 50% of fevers in children younger than 5 years old with microscopy-confirmed Plasmodium falciparum infection, and less than 20% of such fevers in school-age children. Outpatient settings in Malawi had a high burden of malaria illness, but also possible overdiagnosis of malaria illness. Interventions to reduce malaria transmission and rapid testing for other common febrile illness may improve diagnostic clarity among outpatients in malaria endemic settings.


Asunto(s)
Enfermedades Endémicas , Monitoreo Epidemiológico , Malaria Falciparum/diagnóstico , Malaria Falciparum/epidemiología , Sobrediagnóstico/estadística & datos numéricos , Preescolar , Femenino , Fiebre/epidemiología , Fiebre/etiología , Humanos , Lactante , Recién Nacido , Malaui/epidemiología , Masculino , Plasmodium falciparum/patogenicidad , Valor Predictivo de las Pruebas , Estaciones del Año
13.
Retrovirology ; 7: 50, 2010 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-20525366

RESUMEN

BACKGROUND: HTLV-1 is endemic in Guinea-Bissau, and the highest prevalence in the adult population (5.2%) was observed in a rural area, Caió, in 1990. HIV-1 and HIV-2 are both prevalent in this area as well. Cross-sectional associations have been reported for HTLV-1 with HIV infection, but the trends in prevalence of HTLV-1 and HIV associations are largely unknown, especially in Sub Saharan Africa. In the current study, data from three cross-sectional community surveys performed in 1990, 1997 and 2007, were used to assess changes in HTLV-1 prevalence, incidence and its associations with HIV-1 and HIV-2 and potential risk factors. RESULTS: HTLV-1 prevalence was 5.2% in 1990, 5.9% in 1997 and 4.6% in 2007. Prevalence was higher among women than men in all 3 surveys and increased with age. The Odds Ratio (OR) of being infected with HTLV-1 was significantly higher for HIV positive subjects in all surveys after adjustment for potential confounding factors. The risk of HTLV-1 infection was higher in subjects with an HTLV-1 positive mother versus an uninfected mother (OR 4.6, CI 2.6-8.0). The HTLV-1 incidence was stable between 1990-1997 (Incidence Rate (IR) 1.8/1,000 pyo) and 1997-2007 (IR 1.6/1,000 pyo) (Incidence Rate Ratio (IRR) 0.9, CI 0.4-1.7). The incidence of HTLV-1 among HIV-positive individuals was higher compared to HIV negative individuals (IRR 2.5, CI 1.0-6.2), while the HIV incidence did not differ by HTLV-1 status (IRR 1.2, CI 0.5-2.7). CONCLUSIONS: To our knowledge, this is the largest community based study that has reported on HTLV-1 prevalence and associations with HIV. HTLV-1 is endemic in this rural community in West Africa with a stable incidence and a high prevalence. The prevalence increases with age and is higher in women than men. HTLV-1 infection is associated with HIV infection, and longitudinal data indicate HIV infection may be a risk factor for acquiring HTLV-1, but not vice versa. Mother to child transmission is likely to contribute to the epidemic.


Asunto(s)
Infecciones por VIH/epidemiología , VIH-1/aislamiento & purificación , VIH-2/aislamiento & purificación , Infecciones por HTLV-I/epidemiología , Virus Linfotrópico T Tipo 1 Humano/aislamiento & purificación , Adolescente , Adulto , Factores de Edad , Anciano , Comorbilidad , Estudios Transversales , Femenino , Guinea Bissau/epidemiología , Infecciones por VIH/complicaciones , Infecciones por VIH/virología , Infecciones por HTLV-I/complicaciones , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Prevalencia , Factores de Riesgo , Factores Sexuales , Adulto Joven
14.
Virol J ; 7: 230, 2010 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-20843322

RESUMEN

BACKGROUND: The prevalence of HIV/hepatitis co-infection in sub-Saharan Africa is not well documented, while both HIV and HBV are endemic in this area. OBJECTIVE: The aim of this study is to determine the seroprevalence of HBV and HCV virus in HIV-infected subjects in the Gambia. METHODS: Plasma samples from HIV infected patients (190 individuals with clinically defined AIDS and 382 individuals without AIDS) were tested retrospectively for the presence of HBV sero-markers and for serum HBV DNA, screened for HCV infection by testing for anti-HCV antibody and HCV RNA. RESULTS: HBsAg prevalence in HIV-positive individuals is 12.2%. HIV/HBV co-infected individuals with CD4 count of <200 cells µL⁻¹ have a higher HBV DNA viral load than patients with higher CD4 count (log 4.0 vs. log 2.0 DNA copies/ml, p < 0.05). Males (OR = 1.8, 95% CI: 1.0, 3.2) were more likely to be HBsAg positive than female. HCV seroprevalence was 0.9% in HIV-positive individuals. CONCLUSION: The prevalence of HBsAg carriage in HIV- infected Gambians is similar to that obtained in the general population. However co-infected individuals with reduced CD4 levels, indicative of AIDS had higher prevalence of HBeAg retention and elevated HBV DNA levels compared to non-AIDS patients with higher CD4 count.


Asunto(s)
Infecciones por VIH/complicaciones , Hepatitis B/epidemiología , Hepatitis C/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Recuento de Linfocito CD4 , Niño , Preescolar , Comorbilidad , ADN Viral/sangre , Femenino , Gambia/epidemiología , Infecciones por VIH/virología , VIH-1/aislamiento & purificación , VIH-2/aislamiento & purificación , Antígenos de Superficie de la Hepatitis B/sangre , Anticuerpos contra la Hepatitis C/sangre , Humanos , Lactante , Masculino , Persona de Mediana Edad , ARN Viral/sangre , Estudios Retrospectivos , Estudios Seroepidemiológicos , Adulto Joven
15.
Parasit Vectors ; 13(1): 430, 2020 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-32843082

RESUMEN

BACKGROUND: Malaria is still a heavy public health concern in Madagascar. Few studies combining parasitology and entomology have been conducted despite the need for accurate information to design effective vector control measures. In a Malagasy region of moderate to intense transmission of both Plasmodium falciparum and P. vivax, parasitology and entomology have been combined to survey malaria transmission in two nearby villages. METHODS: Community-based surveys were conducted in the villages of Ambohitromby and Miarinarivo at three time points (T1, T2 and T3) during a single malaria transmission season. Human malaria prevalence was determined by rapid diagnostic tests (RDTs), microscopy and real-time PCR. Mosquitoes were collected by human landing catches and pyrethrum spray catches and the presence of Plasmodium sporozoites was assessed by TaqMan assay. RESULTS: Malaria prevalence was not significantly different between villages, with an average of 8.0% by RDT, 4.8% by microscopy and 11.9% by PCR. This was mainly due to P. falciparum and to a lesser extent to P. vivax. However, there was a significantly higher prevalence rate as determined by PCR at T2 ([Formula: see text] = 7.46, P = 0.025). Likewise, mosquitoes were significantly more abundant at T2 ([Formula: see text] = 64.8, P < 0.001), especially in Ambohitromby. At T1 and T3 mosquito abundance was higher in Miarinarivo than in Ambohitromby ([Formula: see text] = 14.92, P < 0.001). Of 1550 Anopheles mosquitoes tested, 28 (1.8%) were found carrying Plasmodium sporozoites. The entomological inoculation rate revealed that Anopheles coustani played a major contribution in malaria transmission in Miarinarivo, being responsible of 61.2 infective bites per human (ib/h) during the whole six months of the survey, whereas, it was An. arabiensis, with 36 ib/h, that played that role in Ambohitromby. CONCLUSIONS: Despite a similar malaria prevalence in two nearby villages, the entomological survey showed a different contribution of An. coustani and An. arabiensis to malaria transmission in each village. Importantly, the suspected secondary malaria vector An. coustani, was found playing the major role in malaria transmission in one village. This highlights the importance of combining parasitology and entomology surveys for better targeting local malaria vectors. Such study should contribute to the malaria pre-elimination goal established under the 2018-2022 National Malaria Strategic Plan.


Asunto(s)
Anopheles/parasitología , Plasmodium falciparum/aislamiento & purificación , Plasmodium vivax/aislamiento & purificación , Animales , Vectores de Enfermedades , Madagascar/epidemiología , Malaria Falciparum/transmisión , Malaria Vivax/parasitología , Malaria Vivax/transmisión , Microscopía , Mosquitos Vectores/parasitología , Reacción en Cadena de la Polimerasa/métodos , Coloración y Etiquetado/métodos
16.
Front Chem ; 8: 173, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32232027

RESUMEN

Controlling mechanical properties of polymeric biomaterials, including the elastic modulus, is critical to direct cell behavior, such as proliferation and differentiation. Dityrosine photocrosslinking is an attractive and simple method to prepare materials that exhibit a wide range of elastic moduli by rapidly crosslinking tyrosyl-containing polymers. However, high concentrations of commonly used oxidative crosslinking reagents, such as ruthenium-based photoinitiators and persulfates, present cytotoxicity concerns. We found the elastic moduli of materials prepared by crosslinking an artificial protein with tightly controlled tyrosine molarity can be modulated up to 40 kPa by adjusting photoinitiator and persulfate concentrations. Formulations with various concentrations of the crosslinking reagents were able to target a similar material elastic modulus, but excess unreacted persulfate resulted in cytotoxic materials. Therefore, we identified a systematic method to prepare non-cytotoxic photocrosslinked polymeric materials with targeted elastic moduli for potential biomaterials applications in diverse fields, including tissue engineering and 3D bioprinting.

17.
Sex Transm Dis ; 36(12): 745-9, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19704397

RESUMEN

BACKGROUND: Syphilis is a common disease in Africa and may be an important contributor to the HIV epidemic. Trends in syphilis prevalence are important in their own right and because syphilis is a cofactor for HIV infection. In this study we analyzed trends in serological syphilis prevalence at a sexually transmitted infections (STI) clinic in The Gambia. METHODS: At the Genitourinary Medicine clinic of the Medical Research Council in The Gambia patients were routinely screened for syphilis using a 2-test algorithm, measuring rapid plasma reagin followed by the Treponema pallidum haemagglutination assay. Serological syphilis was defined as both tests being positive. We determined year to year trends in serological syphilis. Logistic regression was used to identify risk factors. RESULTS: Over the period 1994-2007, 23,674 people were tested for syphilis. The prevalence of serological syphilis dropped from 11.2% in 1994 to 1.5% in 2007 (P <0.0001; chi test for trend). Significant risk factors for serological syphilis in women were found to be ethnicity, commercial sex work, and HIV infection. No associations between serological syphilis and possible risk factors in men were found. CONCLUSIONS: This study identified a strong and significant downward trend in the prevalence of serological syphilis among patients attending the Genitourinary Medicine clinic in The Gambia in the period 1994-2007. These results suggest that syphilis prevalence may be declining in the general population, in the absence of a targeted control program. Research is needed to identify the reasons for this decline.


Asunto(s)
Instituciones de Atención Ambulatoria/estadística & datos numéricos , Serodiagnóstico de la Sífilis , Sífilis/epidemiología , Treponema pallidum , Adolescente , Adulto , Femenino , Gambia/epidemiología , Infecciones por VIH/complicaciones , Infecciones por VIH/epidemiología , Infecciones por VIH/virología , VIH-1 , VIH-2 , Humanos , Masculino , Persona de Mediana Edad , Vigilancia de la Población , Prevalencia , Factores de Riesgo , Trabajo Sexual , Enfermedades de Transmisión Sexual/diagnóstico , Enfermedades de Transmisión Sexual/epidemiología , Enfermedades de Transmisión Sexual/etiología , Enfermedades de Transmisión Sexual/prevención & control , Sífilis/diagnóstico , Sífilis/microbiología , Sífilis/prevención & control , Adulto Joven
18.
PLoS One ; 14(4): e0208155, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31009480

RESUMEN

Influenza virus infections cause between 291 243 and 645 832 deaths annually, with the highest burden in low-income settings. Research in high-income countries has examined public understanding of influenza, but there is little information on views and behaviours about influenza in low-income countries. We explored communities' ideas about the severity, causes, prevention and treatment of influenza in Chikwawa district, Malawi. We conducted 64 in-depth interviews with parents of children aged <5 years, and 7 focus groups with community health workers, parents, and traditional healers. Data were analysed thematically and using a framework matrix to compare views between groups. Respondents held varied ideas about influenza, and many were uncertain about its causes and treatment. Some parents, traditional healers and health workers thought influenza was not severe because they felt it did not cause death or limit activities, but others disagreed. Many saw influenza as a symptom of other conditions, especially malaria and pneumonia, rather than as a disease of its own. Most mentioned dust as the main cause of influenza and believed influenza could be prevented by cleaning the home thoroughly. Treatment seeking for influenza followed different stages, usually starting with home remedies followed by purchasing drugs from groceries and then visiting a health centre. Seeking a clinician tended to be triggered by severe symptoms like high fever or difficulty breathing, and suspicions of malaria or pneumonia. Community health workers provide health education for communities, but some lacked understanding of influenza. Our findings suggest uncertainty about the causes and control of influenza among parents and varied levels of understanding among health providers. Strengthening the capacity of community health workers to provide relevant information about influenza prevention and treatment could address parents' interest in further information and support informed health seeking and engagement with future influenza interventions.


Asunto(s)
Gripe Humana/epidemiología , Preescolar , Agentes Comunitarios de Salud , Grupos Focales , Conocimientos, Actitudes y Práctica en Salud , Humanos , Lactante , Gripe Humana/prevención & control , Gripe Humana/terapia , Malaui/epidemiología , Padres , Educación del Paciente como Asunto , Pobreza
19.
BMJ Open ; 9(9): e025576, 2019 09 12.
Artículo en Inglés | MEDLINE | ID: mdl-31515413

RESUMEN

INTRODUCTION: In Sub-Saharan Africa, the rising rates of cerebrovascular and cardiovascular diseases (CBD/CVD) are intersecting with an ageing HIV-infected population. The widespread use of antiretroviral therapy (ART) may confer an additive risk and may not completely suppress the risk associated with HIV infection. High-quality prospective studies are needed to determine if HIV-infected patients in Africa are at increased risk of CBD/CVD and to identify factors associated with this risk. This study will test the hypothesis that immune activation and dysfunction, driven by HIV and reactivation of latent herpesvirus infections, lead to increased CBD/CVD risk in Malawian adults aged ≥35 years. METHODS AND ANALYSIS: We will conduct a single-centre, 36-month, prospective cohort study in 800 HIV-infected patients initiating ART and 190 HIV-uninfected controls in Blantyre, Malawi. Patients and controls will be recruited from government ART clinics and the community, respectively, and will be frequency-matched by 5-year age band and sex. At baseline and follow-up visits, we will measure carotid intima-media thickness and pulse wave velocity as surrogate markers of vasculopathy, and will be used to estimate CBD/CVD risk. Our primary exposures of interest are cytomegalovirus and varicella zoster reactivation, changes in HIV plasma viral load, and markers of systemic inflammation and endothelial function. Multivariable regression models will be developed to assess the study's primary hypothesis. The occurrence of clinical CBD/CVD will be assessed as secondary study endpoints. ETHICS AND DISSEMINATION: The University of Malawi College of Medicine and Liverpool School of Tropical Medicine research ethics committees approved this work. Our goal is to understand the pathogenesis of CBD/CVD among HIV cohorts on ART, in Sub-Saharan Africa, and provide data to inform future interventional clinical trials. This study runs between May 2017 and August 2020. Results of the main trial will be submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ISRCTN42862937.


Asunto(s)
Terapia Antirretroviral Altamente Activa , Enfermedades Cardiovasculares/epidemiología , Trastornos Cerebrovasculares/epidemiología , Infecciones por VIH/tratamiento farmacológico , Herpesviridae/fisiología , Activación Viral , Adulto , Biomarcadores , Enfermedades Cardiovasculares/diagnóstico por imagen , Grosor Intima-Media Carotídeo , Trastornos Cerebrovasculares/diagnóstico por imagen , Estudios de Cohortes , Infecciones por VIH/epidemiología , Herpesviridae/efectos de los fármacos , Humanos , Inflamación/complicaciones , Malaui , Análisis de la Onda del Pulso , Análisis de Regresión , Proyectos de Investigación , Medición de Riesgo , Factores de Riesgo
20.
Soc Sci Med ; 213: 190-198, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30142500

RESUMEN

Ethics guidelines emphasise that research should be acceptable to the people invited to take part. However, acceptability is subjective and dependent on context, complicating its assessment and use as an ethical standard. This paper examines the concept of acceptability in relation to parents' perspectives on a paediatric vaccine trial in Malawi. We examined decisions on participation and experiences of the trial through interviews with parents in 41 households invited to enrol their children and participant observation of trial processes. Fieldwork took place in Chikwawa, Southern Malawi from February-October 2016. Parents were not neatly split between those who saw the trial as acceptable and those who did not; instead there were mixed and changing feelings among parents who enrolled their children, and among those who withdrew or did not take part. Some parents agreed to participate but had concerns about the trial, while others expressed satisfaction with the trial but still did not take part. These experiences indicate substantial variation in the nature of acceptance. We describe these variations in relation to six dimensions of acceptability: how acceptable the trial is, what aspects are acceptable, changes over time, circumstances affecting acceptability, variations between people, and reasons for participation or non-participation. The findings illustrate the difficulty of determining whether a trial is sufficiently acceptable to potential participants. We suggest that clarifying definitions of acceptability and examining how acceptability varies in degree, between trial components, over time, and between people and contexts may help researchers generate more nuanced descriptions of acceptability that support responsive and ethical trial design.


Asunto(s)
Ensayos Clínicos como Asunto , Toma de Decisiones , Padres/psicología , Aceptación de la Atención de Salud/psicología , Vacunas/administración & dosificación , Preescolar , Femenino , Humanos , Lactante , Malaui , Masculino , Aceptación de la Atención de Salud/estadística & datos numéricos
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