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1.
Nature ; 617(7961): 555-563, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36996873

RESUMO

An outbreak of acute hepatitis of unknown aetiology in children was reported in Scotland1 in April 2022 and has now been identified in 35 countries2. Several recent studies have suggested an association with human adenovirus with this outbreak, a virus not commonly associated with hepatitis. Here we report a detailed case-control investigation and find an association between adeno-associated virus 2 (AAV2) infection and host genetics in disease susceptibility. Using next-generation sequencing, PCR with reverse transcription, serology and in situ hybridization, we detected recent infection with AAV2 in plasma and liver samples in 26 out of 32 (81%) cases of hepatitis compared with 5 out of 74 (7%) of samples from unaffected individuals. Furthermore, AAV2 was detected within ballooned hepatocytes alongside a prominent T cell infiltrate in liver biopsy samples. In keeping with a CD4+ T-cell-mediated immune pathology, the human leukocyte antigen (HLA) class II HLA-DRB1*04:01 allele was identified in 25 out of 27 cases (93%) compared with a background frequency of 10 out of 64 (16%; P = 5.49 × 10-12). In summary, we report an outbreak of acute paediatric hepatitis associated with AAV2 infection (most likely acquired as a co-infection with human adenovirus that is usually required as a 'helper virus' to support AAV2 replication) and disease susceptibility related to HLA class II status.


Assuntos
Infecções por Adenovirus Humanos , Dependovirus , Hepatite , Criança , Humanos , Doença Aguda/epidemiologia , Infecções por Adenovirus Humanos/epidemiologia , Infecções por Adenovirus Humanos/genética , Infecções por Adenovirus Humanos/virologia , Alelos , Estudos de Casos e Controles , Linfócitos T CD4-Positivos/imunologia , Coinfecção/epidemiologia , Coinfecção/virologia , Dependovirus/isolamento & purificação , Predisposição Genética para Doença , Vírus Auxiliares/isolamento & purificação , Hepatite/epidemiologia , Hepatite/genética , Hepatite/virologia , Hepatócitos/virologia , Cadeias HLA-DRB1/genética , Cadeias HLA-DRB1/imunologia , Fígado/virologia
2.
Cell Immunol ; 395-396: 104797, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38157646

RESUMO

Vγ9Vδ2 T lymphocytes are programmed for broad antimicrobial responses with rapid production of Th1 cytokines even before birth, and thus thought to play key roles against pathogens in infants. The process regulating Vδ2 cell acquisition of cytotoxic potential shortly after birth remains understudied. We observed that perforin production in cord blood Vδ2 cells correlates with phenotypes defined by the concomitant assessment of PD-1 and CD56. Bulk RNA sequencing of sorted Vδ2 cell fractions indicated that transcripts related to cytotoxic activity and NK function are enriched in the subset with the highest proportion of perforin+ cells. Among differentially expressed transcripts, IRF8, previously linked to CD8 T cell effector differentiation and NK maturation, has the potential to mediate Vδ2 cell differentiation towards cytotoxic effectors. Our current and past results support the hypothesis that distinct mechanisms regulate Vδ2 cell cytotoxic function before and after birth, possibly linked to different levels of microbial exposure.


Assuntos
Antígeno CD56 , Linfócitos T CD8-Positivos , Citotoxicidade Imunológica , Receptor de Morte Celular Programada 1 , Receptores de Antígenos de Linfócitos T gama-delta , Subpopulações de Linfócitos T , Humanos , Linfócitos T CD8-Positivos/imunologia , Citocinas/metabolismo , Sangue Fetal , Perforina/genética , Perforina/metabolismo , Receptor de Morte Celular Programada 1/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Subpopulações de Linfócitos T/imunologia , Antígeno CD56/metabolismo
3.
Malar J ; 22(1): 32, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36707795

RESUMO

BACKGROUND: When people with human immunodeficiency virus (HIV) infection (PWH) develop malaria, they are at risk of poor anti-malarial treatment efficacy resulting from impairment in the immune response and/or drug-drug interactions that alter anti-malarial metabolism. The therapeutic efficacy of artemether-lumefantrine was evaluated in a cohort of PWH on antiretroviral therapy (ART) and included measurement of day 7 lumefantrine levels in a subset to evaluate for associations between lumefantrine exposure and treatment response. METHODS: Adults living with HIV (≥ 18 years), on ART for ≥ 6 months with undetectable HIV RNA viral load and CD4 count ≥ 250/mm3 were randomized to daily trimethoprim-sulfamethoxazole (TS), weekly chloroquine (CQ) or no prophylaxis. After diagnosis of uncomplicated Plasmodium falciparum malaria, a therapeutic efficacy monitoring was conducted with PCR-correction according to WHO guidelines. The plasma lumefantrine levels on day 7 in 100 episodes of uncomplicated malaria was measured. A frailty proportional hazards model with random effects models to account for clustering examined the relationship between participant characteristics and malaria treatment failure within 28 days. Pearson's Chi-squared test was used to compare lumefantrine concentrations among patients with treatment failure and adequate clinical and parasitological response (ACPR). RESULTS: 411 malaria episodes were observed among 186 participants over 5 years. The unadjusted ACPR rate was 81% (95% CI 77-86). However, after PCR correction to exclude new infections, ACPR rate was 94% (95% CI 92-97). Increasing age and living in Ndirande were associated with decreased hazard of treatment failure. In this population of adults with HIV on ART, 54% (51/94) had levels below a previously defined optimal day 7 lumefantrine level of 200 ng/ml. This occurred more commonly among participants who were receiving an efavirenz-based ART compared to other ART regimens (OR 5.09 [95% CI 1.52-7.9]). Participants who experienced treatment failure had lower day 7 median lumefantrine levels (91 ng/ml [95% CI 48-231]) than participants who experienced ACPR (190 ng/ml [95% CI 101-378], p-value < 0.008). CONCLUSION: Recurrent malaria infections are frequent in this population of PWH on ART. The PCR-adjusted efficacy of AL meets the WHO criteria for acceptable treatment efficacy. Nevertheless, lumefantrine levels tend to be low in this population, particularly in those on efavirenz-based regimens, with lower concentrations associated with more frequent malaria infections following treatment. These results highlight the importance of understanding drug-drug interactions when diseases commonly co-occur.


Assuntos
Antimaláricos , Artemisininas , Infecções por HIV , Malária Falciparum , Malária , Humanos , Adulto , Antimaláricos/uso terapêutico , Malaui , Artemisininas/uso terapêutico , Artemeter/uso terapêutico , Combinação de Medicamentos , Combinação Arteméter e Lumefantrina/uso terapêutico , Malária/tratamento farmacológico , Malária Falciparum/tratamento farmacológico , Malária Falciparum/prevenção & controle , Lumefantrina/uso terapêutico , Infecções por HIV/tratamento farmacológico , Resultado do Tratamento , Etanolaminas/uso terapêutico , Fluorenos/uso terapêutico
4.
BMC Health Serv Res ; 23(1): 1288, 2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-37996862

RESUMO

BACKGROUND: Rapid diagnostic testing may support improved treatment of COVID patients. Understanding COVID testing and care pathways is important for assessing the impact and cost-effectiveness of testing in the real world, yet there is limited information on these pathways in low-and-middle income countries (LMICs). We therefore undertook an expert consultation to better understand testing policies and practices, clinical screening, the profile of patients seeking testing or care, linkage to care after testing, treatment, lessons learnt and expected changes in 2023. METHODS: We organized a qualitative consultation with ten experts from seven LMICs (India, Indonesia, Malawi, Nigeria, Peru, South Africa, and Zimbabwe) identified through purposive sampling. We conducted structured interviews during six regional consultations, and undertook a thematic analysis of responses. RESULTS: Participants reported that, after initial efforts to scale-up testing, the policy priority given to COVID testing has declined. Comorbidities putting patients at heightened risk (e.g., diabetes) mainly relied on self-identification. The decision to test following clinical screening was highly context-/location-specific, often dictated by local epidemiology and test availability. When rapid diagnostic tests were available, public sector healthcare providers tended to rely on them for diagnosis (alongside PCR for Asian/Latin American participants), while private sector providers predominantly used polymerase chain reaction (PCR) tests. Positive test results were generally taken at 'face value' by clinicians, although negative tests with a high index of suspicion may be confirmed with PCR. However, even with a positive result, patients were not always linked to care in a timely manner because of reluctance to receiving care or delays in returning to care centres upon clinical deterioration. Countries often lacked multiple components of the range of therapeutics advised in WHO guidelines: notably so for oral antivirals designed for high-risk mild patients. Severely ill patients mostly received corticosteroids and, in higher-resourced settings, tocilizumab. CONCLUSIONS: Testing does not always prompt enhanced care, due to reluctance on the part of patients and limited therapeutic availability within clinical settings. Any analysis of the impact or cost-effectiveness of testing policies post pandemic needs to either consider investment in optimal treatment pathways or constrain estimates of benefits based on actual practice.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico , COVID-19/epidemiologia , Países em Desenvolvimento , Teste para COVID-19 , Procedimentos Clínicos , Encaminhamento e Consulta
5.
Emerg Infect Dis ; 28(13): S76-S84, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36502413

RESUMO

To determine early COVID-19 burden in Malawi, we conducted a multistage cluster survey in 5 districts. During October-December 2020, we recruited 5,010 community members (median age 32 years, interquartile range 21-43 years) and 1,021 health facility staff (HFS) (median age 35 years, interquartile range 28-43 years). Real-time PCR-confirmed SARS-CoV-2 infection prevalence was 0.3% (95% CI 0.2%-0.5%) among community and 0.5% (95% CI 0.1%-1.2%) among HFS participants; seroprevalence was 7.8% (95% CI 6.3%-9.6%) among community and 9.7% (95% CI 6.4%-14.5%) among HFS participants. Most seropositive community (84.7%) and HFS (76.0%) participants were asymptomatic. Seroprevalence was higher among urban community (12.6% vs. 3.1%) and HFS (14.5% vs. 7.4%) than among rural community participants. Cumulative infection findings 113-fold higher from this survey than national statistics (486,771 vs. 4,319) and predominantly asymptomatic infections highlight a need to identify alternative surveillance approaches and predictors of severe disease to inform national response.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Adulto Jovem , Adulto , COVID-19/epidemiologia , Estudos Soroepidemiológicos , Pessoal de Saúde , Prevalência , Anticorpos Antivirais
6.
Malar J ; 21(1): 292, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36224585

RESUMO

BACKGROUND: The prevalence of small for gestational age (SGA) may vary depending on the chosen weight-for-gestational-age reference chart. An individual participant data meta-analysis was conducted to assess the implications of using a local reference (STOPPAM) instead of a universal reference (Intergrowth-21) on the association between malaria in pregnancy and SGA. METHODS: Individual participant data of 6,236 newborns were pooled from seven conveniently identified studies conducted in Tanzania and Malawi from 2003-2018 with data on malaria in pregnancy, birthweight, and ultrasound estimated gestational age. Mixed-effects regression models were used to compare the association between malaria in pregnancy and SGA when using the STOPPAM and the Intergrowth-21 references, respectively. RESULTS: The 10th percentile for birthweights-for-gestational age was lower for STOPPAM than for Intergrowth-21, leading to a prevalence of SGASTOPPAM of 14.2% and SGAIG21 of 18.0%, p < 0.001. The association between malaria in pregnancy and SGA was stronger for STOPPAM (adjusted odds ratio (aOR) 1.30 [1.09-1.56], p < 0.01) than for Intergrowth-21 (aOR 1.19 [1.00-1.40], p = 0.04), particularly among paucigravidae (SGASTOPPAM aOR 1.36 [1.09-1.71], p < 0.01 vs SGAIG21 aOR 1.21 [0.97-1.50], p = 0.08). CONCLUSIONS: The prevalence of SGA may be overestimated and the impact of malaria in pregnancy underestimated when using Intergrowth-21. Comparing local reference charts to global references when assessing and interpreting the impact of malaria in pregnancy may be appropriate.


Assuntos
Recém-Nascido Pequeno para a Idade Gestacional , Malária , Peso ao Nascer , Feminino , Retardo do Crescimento Fetal , Idade Gestacional , Humanos , Recém-Nascido , Malária/epidemiologia , Gravidez , Tanzânia/epidemiologia
7.
Euro Surveill ; 27(15)2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35426362

RESUMO

On 31 March 2022, Public Health Scotland was alerted to five children aged 3-5 years admitted to hospital with severe hepatitis of unknown aetiology. Retrospective investigation identified eight additional cases aged 10 years and younger since 1 January 2022. Two pairs of cases have epidemiological links. Common viral hepatitis causes were excluded in those with available results. Five children were adenovirus PCR-positive. Other childhood viruses, including SARS-CoV-2, have been isolated. Investigations are ongoing, with new cases still presenting.


Assuntos
COVID-19 , Hepatite A , Criança , Pré-Escolar , Humanos , Estudos Retrospectivos , SARS-CoV-2 , Escócia/epidemiologia
8.
Clin Infect Dis ; 73(6): 1058-1065, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-33744963

RESUMO

BACKGROUND: Daily co-trimoxazole is recommended for African adults living with human immunodeficiency virus (HIV) irrespective of antiretroviral treatment, immune status, or disease stage. Benefits of continued prophylaxis and whether co-trimoxazole can be stopped following immune reconstitution are unknown. METHODS: We conducted a randomized controlled trial at 2 sites in Malawi that enrolled adults with HIV with undetectable viral load and CD4 count of >250/mm3 and randomized them to continue daily co-trimoxazole, discontinue daily co-trimoxazole and begin weekly chloroquine, or discontinue daily co-trimoxazole. The primary endpoint was the preventive effect of co-trimoxazole prophylaxis against death or World Health Organization (WHO) HIV/AIDS stage 3-4 events, using Cox proportional hazards modeling, in an intention-to-treat population. RESULTS: 1499 adults were enrolled. The preventive effect of co-trimoxazole on the primary endpoint was 22% (95% CI: -14%-47%; P = .20) versus no prophylaxis and 25% (-10%-48%; P = .14) versus chloroquine. When WHO HIV/AIDS stage 2 events were added to the primary endpoint, preventive effect increased to 31% (3-51%; P = .032) and 32% (4-51%; P = .026), respectively. Co-trimoxazole and chloroquine prophylaxis effectively prevented clinical malaria episodes (3.8 and 3.0, respectively, vs 28/100 person-years; P < .001). CONCLUSIONS: Malawian adults with HIV who immune reconstituted on ART and continued co-trimoxazole prophylaxis experienced fewer deaths and WHO HIV/AIDS stage 3-4 events compared with prophylaxis discontinuation, although statistical significance was not achieved. Co-trimoxazole prevented a composite of death plus WHO HIV/AIDS stage 2-4 events. Given poor healthcare access and lack of routine viral load monitoring, co-trimoxazole prophylaxis should continue in adults on ART after immune reconstitution in sub-Saharan Africa. Clinical Trials Registration. NCT01650558.


Assuntos
Infecções por HIV , Combinação Trimetoprima e Sulfametoxazol , Adulto , Antirretrovirais/uso terapêutico , Contagem de Linfócito CD4 , Infecções por HIV/tratamento farmacológico , Infecções por HIV/prevenção & controle , Humanos , Malaui/epidemiologia , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico
9.
Emerg Infect Dis ; 27(7): 1831-1839, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34152962

RESUMO

The coronavirus disease (COVID-19) pandemic might affect tuberculosis (TB) diagnosis and patient care. We analyzed a citywide electronic TB register in Blantyre, Malawi and interviewed TB officers. Malawi did not have an official COVID-19 lockdown but closed schools and borders on March 23, 2020. In an interrupted time series analysis, we noted an immediate 35.9% reduction in TB notifications in April 2020; notifications recovered to near prepandemic numbers by December 2020. However, 333 fewer cumulative TB notifications were received than anticipated. Women and girls were affected more (30.7% fewer cases) than men and boys (20.9% fewer cases). Fear of COVID-19 infection, temporary facility closures, inadequate personal protective equipment, and COVID-19 stigma because of similar symptoms to TB were mentioned as reasons for fewer people being diagnosed with TB. Public health measures could benefit control of both TB and COVID-19, but only if TB diagnostic services remain accessible and are considered safe to attend.


Assuntos
COVID-19 , Tuberculose , Controle de Doenças Transmissíveis , Feminino , Humanos , Malaui/epidemiologia , Masculino , Pandemias , SARS-CoV-2 , Tuberculose/diagnóstico , Tuberculose/epidemiologia
10.
PLoS Med ; 18(9): e1003752, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34499665

RESUMO

BACKGROUND: Suboptimal tuberculosis (TB) diagnostics and HIV contribute to the high global burden of TB. We investigated costs and yield from systematic HIV-TB screening, including computer-aided digital chest X-ray (DCXR-CAD). METHODS AND FINDINGS: In this open, three-arm randomised trial, adults (≥18 years) with cough attending acute primary services in Malawi were randomised (1:1:1) to standard of care (SOC); oral HIV testing (HIV screening) and linkage to care; or HIV testing and linkage to care plus DCXR-CAD with sputum Xpert for high CAD4TBv5 scores (HIV-TB screening). Participants and study staff were not blinded to intervention allocation, but investigator blinding was maintained until final analysis. The primary outcome was time to TB treatment. Secondary outcomes included proportion with same-day TB treatment; prevalence of undiagnosed/untreated bacteriologically confirmed TB on day 56; and undiagnosed/untreated HIV. Analysis was done on an intention-to-treat basis. Cost-effectiveness analysis used a health-provider perspective. Between 15 November 2018 and 27 November 2019, 8,236 were screened for eligibility, with 473, 492, and 497 randomly allocated to SOC, HIV, and HIV-TB screening arms; 53 (11%), 52 (9%), and 47 (9%) were lost to follow-up, respectively. At 56 days, TB treatment had been started in 5 (1.1%) SOC, 8 (1.6%) HIV screening, and 15 (3.0%) HIV-TB screening participants. Median (IQR) time to TB treatment was 11 (6.5 to 38), 6 (1 to 22), and 1 (0 to 3) days (hazard ratio for HIV-TB versus SOC: 2.86, 1.04 to 7.87), with same-day treatment of 0/5 (0%) SOC, 1/8 (12.5%) HIV, and 6/15 (40.0%) HIV-TB screening arm TB patients (p = 0.03). At day 56, 2 SOC (0.5%), 4 HIV (1.0%), and 2 HIV-TB (0.5%) participants had undiagnosed microbiologically confirmed TB. HIV screening reduced the proportion with undiagnosed or untreated HIV from 10 (2.7%) in the SOC arm to 2 (0.5%) in the HIV screening arm (risk ratio [RR]: 0.18, 0.04 to 0.83), and 1 (0.2%) in the HIV-TB screening arm (RR: 0.09, 0.01 to 0.71). Incremental costs were US$3.58 and US$19.92 per participant screened for HIV and HIV-TB; the probability of cost-effectiveness at a US$1,200/quality-adjusted life year (QALY) threshold was 83.9% and 0%. Main limitations were the lower than anticipated prevalence of TB and short participant follow-up period; cost and quality of life benefits of this screening approach may accrue over a longer time horizon. CONCLUSIONS: DCXR-CAD with universal HIV screening significantly increased the timeliness and completeness of HIV and TB diagnosis. If implemented at scale, this has potential to rapidly and efficiently improve TB and HIV diagnosis and treatment. TRIAL REGISTRATION: clinicaltrials.gov NCT03519425.


Assuntos
Coinfecção , Tosse/diagnóstico , Diagnóstico por Computador , Infecções por HIV/diagnóstico , Teste de HIV , Radiografia Torácica , Tuberculose/diagnóstico por imagem , Adulto , Fármacos Anti-HIV/uso terapêutico , Antituberculosos/uso terapêutico , Análise Custo-Benefício , Tosse/microbiologia , Diagnóstico por Computador/economia , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Teste de HIV/economia , Custos de Cuidados de Saúde , Acessibilidade aos Serviços de Saúde , Humanos , Malaui/epidemiologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prevalência , Atenção Primária à Saúde , Radiografia Torácica/economia , Tuberculose/tratamento farmacológico , Tuberculose/epidemiologia , Tuberculose/microbiologia , Adulto Jovem
11.
Cell Immunol ; 359: 104244, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33248366

RESUMO

Human Vγ9Vδ2 T cells respond to several diverse pathogens by sensing microbial cholesterol intermediates. Unlike CD4 T cells, they are poised for rapid Th1-like responses even before birth, which allows them to play a key role in the first line of defense against pathogens in early life. However, their regulation and functional maturation during infancy (in particular the acquisition of cytotoxic potential) remain understudied. We thus characterized their responses to cholesterol intermediates and Bacille Calmette-Guérin in a cohort of African neonates and 12-month-old infants. Infant Vδ2 lymphocytes exhibited intermediate or adult-like expression of markers associated with differentiation or function, intermediate proliferative responses, and adult-like cytotoxic potential. The enhancement of Vδ2 cell cytotoxic potential coincided with decreasing PD-1 and increasing NKG2A expression. Our results are consistent with the hypothesis that switching from a PD-1+ to a NKG2A+ phenotype during infancy indicates a shift in mechanisms regulating Vδ2 T cell function.


Assuntos
Sangue Fetal/citologia , Receptor de Morte Celular Programada 1/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Adulto , Fatores Etários , Diferenciação Celular/fisiologia , Células Cultivadas , Cordocentese , Feminino , Expressão Gênica/genética , Humanos , Lactente , Recém-Nascido , Interferon gama/metabolismo , Ativação Linfocitária/imunologia , Malaui/epidemiologia , Masculino , Subfamília C de Receptores Semelhantes a Lectina de Células NK/imunologia , Subfamília C de Receptores Semelhantes a Lectina de Células NK/metabolismo , Receptor de Morte Celular Programada 1/genética , Receptores de Antígenos de Linfócitos T gama-delta/genética , Linfócitos T/imunologia
12.
BMC Infect Dis ; 21(1): 178, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33588804

RESUMO

BACKGROUND: Tuberculosis (TB) control relies on early diagnosis and treatment. International guidelines recommend systematic TB screening at health facilities, but implementation is challenging. We investigated completion of recommended TB screening steps in Blantyre, Malawi. METHODS: A prospective cohort recruited adult outpatients attending Bangwe primary clinic. Entry interviews were linked to exit interviews. The proportion of participants progressing through each step of the diagnostic pathway were estimated. Factors associated with request for sputum were investigated using multivariable logistic regression. RESULTS: Of 5442 clinic attendances 2397 (44%) had exit interviews. In clinically indicated participants (n = 445) 256 (57.5%) were asked about cough, 36 (8.1%) were asked for sputum, 21 (4.7%) gave sputum and 1 (0.2%) received same-day results. Significant associations with request for sputum were: any TB symptom (aOR:3.20, 95%CI:2.02-5.06), increasing age (aOR:1.02, 95%CI:1.01-1.04 per year) and for HIV-negative participants only, a history of previous TB (aOR:3.37, 95%CI:1.45-7.81). Numbers requiring sputum tests (26/day) outnumbered diagnostic capacity (8-12/day). CONCLUSIONS: Patients were lost at every stage of the TB care cascade, with same day sputum submission following all steps of the diagnosis cascade achieved in only 4.7% if clinically indicated. Infection control strategies should be implemented, with reporting on early steps of the TB care cascade formalised. High-throughput screening interventions, such as digital CXR, that can achieve same-day TB diagnosis are urgently needed to meet WHO End TB goals.


Assuntos
Programas de Rastreamento/estatística & dados numéricos , Tuberculose/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Instituições de Assistência Ambulatorial , Feminino , Humanos , Entrevistas como Assunto/estatística & dados numéricos , Modelos Logísticos , Malaui/epidemiologia , Masculino , Programas de Rastreamento/métodos , Programas de Rastreamento/normas , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Estudos Prospectivos , Escarro/microbiologia , Tuberculose/epidemiologia , Tuberculose/prevenção & controle , Adulto Jovem
13.
BMC Med Ethics ; 20(1): 82, 2019 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-31727044

RESUMO

BACKGROUND: Compensating participants of biomedical research is a common practice. However, its proximity with ethical concerns of coercion, undue influence, and exploitation, demand that participant compensation be regulated. The objective of this paper is to discuss the current regulations for compensation of research participants in Malawi and how they can be improved in relation to ethical concerns of coercion, undue influence, and exploitation. MAIN TEXT: In Malawi, national regulations recommend that research subjects be compensated with a stipend of US$10 per study visit. However, no guidance is provided on how this figure was determined and how it should be implemented. While necessary to prevent exploitation, the stipend may expose the very poor to undue influence. The stipend may also raise the cost of doing research disadvantaging local researchers and may have implications on studies where income stipend is the intervention under investigation. We recommend that development and implementation of guidelines of this importance involve interested parties such as the research community and patient groups. CONCLUSION: Compensating human research subjects is important but can also act as a barrier to voluntary participation and good research efforts. Deliberate measures need to be put in place to ensure fair compensation of research participants, avoid their exploitation and level the field for locally funded research.


Assuntos
Pesquisa Biomédica/ética , Países em Desenvolvimento , Renda , Sujeitos da Pesquisa , Pesquisa Biomédica/normas , Coerção , Guias como Assunto , Humanos , Malaui
14.
Trop Med Int Health ; 23(5): 526-532, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29505108

RESUMO

OBJECTIVES: WHO recommends HIV viral load (VL) testing 6 months after antiretroviral therapy (ART) initiation and every 12 months thereafter, but cost prohibits routine, universal VL testing in many developing countries. We sought to devise a targeted approach to routine VL monitoring that could reduce cost and identify those at low risk for virologic failure (VF). METHODS: We analysed screening data from a clinical trial enrolling adults on ART in Malawi. We identified risk factors associated with VF and employed the Knill-Jones method to assign summary score identifying persons at lower risk for VF. RESULTS: Among 957 adults, prevalence of VF was 9.4%. Factors independently associated with VF included age <38 years (OR 3.44, 95% CI 2.01-5.89), ART duration >2.5 years (OR 2.98, 95% CI 1.79-4.96), ART adherence <95% (OR 1.76, 95% CI 1.06-2.94), CD4 count <200 cells/µl (OR 5.94, 95% CI 3.27-10.78), haemoglobin <13 g/dl (OR 2.76, 95% CI 1.70-4.50) and CD8 count >885 cells/µl (OR 2.10, 95% CI 1.28-3.44). Our VF prediction summary score included all factors above except CD8 count and was fairly accurate with validated area under receiver operating characteristic curve of 0.76. Implementation could reduce VL testing by 65%. CONCLUSION: A simple score incorporating age, ART duration and adherence, and CD4 count can accurately identify adults at low risk for VF in a sub-Saharan African setting. In areas with high ART utilisation and limited VL testing capacity, a targeted approach could optimise routine VL monitoring while identifying adults in need of alternate ART regimens.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Testes Diagnósticos de Rotina/estatística & dados numéricos , Infecções por HIV/tratamento farmacológico , Adesão à Medicação/estatística & dados numéricos , Carga Viral , Adulto , Terapia Antirretroviral de Alta Atividade , Contagem de Linfócito CD4 , Testes Diagnósticos de Rotina/economia , Feminino , Humanos , Malaui , Masculino , Pessoa de Meia-Idade , Adulto Jovem
15.
J Immunol ; 197(5): 1884-92, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27474072

RESUMO

A successful pregnancy depends on the maintenance of tolerance at the fetal-maternal interface; strong inflammation in the placental bed is generally associated with adverse fetal outcomes. Among the mechanisms that foster tolerance and limit inflammation, the fetal immune system favors Th2 or regulatory responses over Th1 responses. The unintended consequence of this functional program is high susceptibility to infections. Human Vδ2 T cells mount innate-like responses to a broad range of microorganisms and are poised for Th1 responses before birth. In infants they likely play a key role in protection against pathogens by exerting early Th1 effector functions, improving function of other innate cells, and promoting Th1 polarization of adaptive responses. However, their propensity to release Th1 mediators may require careful regulation during fetal life to avoid exaggerated proinflammatory responses. We investigated molecules with the potential to act as a rheostat for fetal Vδ2 cells. Programmed death 1 (PD1) is a negative regulator of T cell responses and a determinant of tolerance, particularly at the fetal-maternal interface. Neonatal Vδ2 cells upregulate PD1 shortly after activation and, unlike their adult counterparts, express this molecule for at least 28 d. Engagement of PD1 by one of its ligands, PDL1, effectively dampens TCR-mediated responses (TNF-α production and degranulation) by neonatal Vδ2 cells and may thus help maintain their activity within safe limits. PD1 expression by neonatal Vδ2 cells is inversely associated with promoter DNA methylation. Prolonged PD1 expression may be part of a functional program to control Vδ2 cell inflammatory responses during fetal life.


Assuntos
Epigênese Genética , Regulação da Expressão Gênica , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Linfócitos T Reguladores/imunologia , Adulto , Antígeno B7-H1/imunologia , Metilação de DNA , Feminino , Desenvolvimento Fetal , Humanos , Tolerância Imunológica , Recém-Nascido , Inflamação/imunologia , Ativação Linfocitária , Gravidez , Regiões Promotoras Genéticas , Células Th1/imunologia , Fatores de Tempo , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/imunologia
16.
J Infect Dis ; 216(6): 732-735, 2017 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-28934438

RESUMO

Pregnancy-associated Plasmodium falciparum infection impacts the health of mothers and newborns, but little is known about the effects of these infections on infant susceptibility to malaria. We followed 473 mother-infant pairs during pregnancy and through 2 years of age. We observed that children born to mothers with placental malaria, but not those born to mothers with peripheral infection without evidence of placental sequestration, had increased risk of malaria during the first year of life compared with children born to mothers with no malaria during pregnancy. Malaria infections with placental sequestration have long-lasting impact on infant susceptibility to malaria infection.


Assuntos
Malária Falciparum/diagnóstico , Doenças Placentárias/diagnóstico , Doenças Placentárias/parasitologia , Placenta/parasitologia , Plasmodium falciparum/isolamento & purificação , Complicações Parasitárias na Gravidez/diagnóstico , Cloroquina/uso terapêutico , Combinação de Medicamentos , Feminino , Seguimentos , Humanos , Lactente , Modelos Logísticos , Estudos Longitudinais , Malária Falciparum/sangue , Análise Multivariada , Doenças Placentárias/sangue , Gravidez , Complicações Parasitárias na Gravidez/sangue , Pirimetamina/uso terapêutico , Fatores de Risco , Sulfadoxina/uso terapêutico
18.
Malar J ; 14: 422, 2015 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-26510414

RESUMO

BACKGROUND: Preventing malaria during pregnancy is important for the health of mothers and newborns. Interventions, which include distribution of bed nets and administration of intermittent preventive treatment (IPT), typically occur at the first antenatal visit, usually in the second or third trimester of pregnancy. In 2012, during the course of ongoing clinical studies of malaria among pregnant women in Malawi, a universal bed net campaign was implemented by the Government. This study tested the hypothesis that a universal bed net campaign would decrease the prevalence of malaria among pregnant women at their first antenatal visit. METHODS: Some 1661 women were recruited for two studies from 2009 to 2014. Quantitative PCR (qPCR) was conducted from dried blood spots collected at the first antenatal care visit (prior to administration of IPT or any study interventions) from women who were in their first or second pregnancy and less than 28 weeks gestation by clinical assessment. RESULTS: Overall, 320 of 1629 (19.6 %) women tested for malaria at their first antenatal visit were infected. Malaria infection rates declined from 28.4 % before the universal bed net campaign, to 18.5 % in 2012, to 15.0 % in the years following the universal bed net campaign. The odds of malaria infection at the time of first antenatal visit in 2012 and the years following the bed net campaign were significantly lower than in the years prior to the intervention (OR 0.6, 95 % CI 0.4-0.8; and OR 0.4, 95 % CI 0.3-0.6, respectively). A similar pattern was observed for the prevalence of clinical malaria. The inverse trend was observed for reported bed net use. However bed net use and malaria infection were not significantly associated on the individual level. CONCLUSIONS: Malaria infection in pregnant women is common even after a bed net campaign in Malawi, though prevalence rates declined. These early infections may cause maternal anaemia and placental malaria resulting in adverse maternal and fetal outcomes. Infection early in pregnancy may also contribute to malaria transmission as pregnant women represent a significant untreated reservoir of parasites. Universal bed net distribution appears to have moderate success in preventing malaria early in pregnancy and these findings support continued efforts to target women early in pregnancy and all women of childbearing age.


Assuntos
Transmissão de Doença Infecciosa/prevenção & controle , Malária/epidemiologia , Malária/prevenção & controle , Controle de Mosquitos/métodos , Mosquiteiros/estatística & dados numéricos , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/prevenção & controle , Adolescente , Adulto , Feminino , Pesquisa sobre Serviços de Saúde , Humanos , Malaui/epidemiologia , Pessoa de Meia-Idade , Gravidez , Prevalência , Adulto Jovem
19.
PLOS Glob Public Health ; 4(3): e0002369, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38498477

RESUMO

The widespread use of antigen-detection rapid diagnostic tests (Ag-RDTs) has revolutionized SARS-CoV-2 (COVID-19) testing, particularly through the option of self-testing. The full extent of Ag-RDT utilization for self-testing, however, remains largely unexplored. To inform the development of WHO guidance on COVID-19 self-testing, we conducted a global consultation to gather the views and experiences of policy makers, researchers, and implementers worldwide. The consultation was conducted by disseminating a WHO questionnaire through professional networks via email and social media, encouraging onward sharing. We used a cross-sectional design with both closed and open-ended questions related to policy and program information concerning the regulation, availability, target population, indications, implementation, benefits, and challenges of COVID-19 self-testing (C19ST). We defined self-testing as tests performed and interpreted by an untrained individual, often at home. Descriptive summaries, cross-tabulations, and proportions were used to calculate outcomes at the global level and by WHO region and World Bank income classifications. All information was collated and reported according to WHO guideline development standards and practice for global consultations. Between 01 and 11 February 2022, 844 individuals from 139 countries responded to the survey, with 45% reporting affiliation with governments and 47% operating at the national level. 504 respondents from 101 countries reported policies supporting C19ST for a range of use cases, including symptomatic and asymptomatic populations. More respondents from low-and-middle-income countries (LMICs) than high-income countries (HICs) reported a lack of an C19ST policy (61 vs 11 countries) and low population-level reach of C19ST. Respondents with C19ST experience perceived that the tests were mostly acceptable to target populations, provided significant benefits, and highlighted several key challenges to be addressed for increased success. Reported costs varied widely, ranging from specific programmes enabling free access to certain users and others with high costs via the private sector. Based on this consultation, systems for the regulatory review, policy development and implementation of C19ST appeared to be much more common in HIC when compared to LIC in early 2022, though most respondents indicated self-testing was available to some extent (101 out of 139 countries) in their country. Addressing such global inequities is critical for ensuring access to innovative and impactful interventions in the context of a public health emergency of international concern. The challenges and opportunities highlighted by key stakeholders could be valuable to consider as future testing strategies are being set for outbreak-prone diseases.

20.
BMJ Open ; 14(1): e077148, 2024 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-38286709

RESUMO

INTRODUCTION: Health-related data collection tools, including digital ones, have become more prevalent across clinical studies in the last number of years. However, using digital data collection tools in low-income and middle-income countries presents unique challenges. In this review, we aim to provide an overview of the data collection tools currently being used in randomised controlled trials (RCTs) conducted in low-resource settings and evaluate the tools based on the characteristics outlined in the modified Mobile Survey Tool framework. These include functionality, reliability, usability, efficiency, maintainability, portability, effectiveness, cost-benefit, satisfaction, freedom from risk and context coverage. This evidence may provide a guide to selecting a suitable data collection tool for researchers planning to conduct research in low-income and middle-income countries for future studies. METHODS AND ANALYSIS: Searches will be conducted in four electronic databases: PubMed, CINAHL, Web of Science and EMBASE. For inclusion, studies must be a RCT, mention a health-related data collection tool and conducted in a low- and middle-income country. Only studies with available full-text and written in English will be included. The search was restricted to studies published between January 2005 and June 2023. This systematic review will use the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) tool. Two review authors will screen the titles and abstracts of search results independently for inclusion. In the initial screening process, the full-text articles will be retrieved if the abstract contains limited information about the study. Disagreements will be resolved through discussion. If the disagreement cannot be resolved, a third author (JO'D) will adjudicate. The study selection process will be outlined in a PRISMA flow-diagram. Data will be analysed using a narrative synthesis approach. The included studies and their outcomes will be presented in a table. ETHICS AND DISSEMINATION: Formal ethical approval is not required as primary data will not be collected in this study. The findings from this systematic review will be published in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42023405738.


Assuntos
Países em Desenvolvimento , Pobreza , Humanos , Análise Custo-Benefício , Coleta de Dados , Ensaios Clínicos Controlados Aleatórios como Assunto , Literatura de Revisão como Assunto , Revisões Sistemáticas como Assunto
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