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2.
Int J Equity Health ; 21(1): 73, 2022 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-35590403

RESUMO

Significant progress has been made to advance Maternal, Newborn and Child Health (MNCH) in Ethiopia. Further, the country has enshrined equity as a core value in their strategic and development frameworks and policies. Although national statistics show improved health outcomes, there exists persistent inequities in avoidable health risks and premature deaths. Additionally, the improving health statistics mask the disparities in health outcomes based on education, employment status, income level, gender and ethnicity dimensions.The EquiFrame framework was used to assess the extent to which equity was entrenched in MNCH health policies and plans. The framework, which describes core concepts against which health policies and plans can be assessed, also provides a scoring criterion for policy assessment. The framework was modified to include the concept of intersectionality, which is increasingly gaining significance in the health policy ecosystems. The policies and plans reviewed in this analysis exercise were selected based on (1) their relevance - only policies and plans in force as of the year 2020 were considered; (2) availability in the public domain as this study was limited to desk research; and (3) relevance to MNCH. A total of five policies and plans were analyzed and evaluated against the 15 core concepts presented in the modified EquiFrame framework. Following the outcomes of the assessment, documents were ranked as either being low, moderate, or high, in exhaustively addressing the core concepts.The Ethiopia Health Sector Transformation Plan (2016-2020) is the only policy or plan that earned a high ranking. The other four policies and plans were ranked as moderate. This shows that while majority of the Ethiopian health sector policies and plans exist and address the core health equity concepts, they fail to: (i) spell out plans to implement and monitor the proposed interventions; and (ii) demonstrate evidence that the interventions were implemented or monitored. With the global goal of leaving no one behind, future policy development in Ethiopia needs to prioritize equity considerations in order to enhance the ongoing health improvement.


Assuntos
Saúde da Criança , Ecossistema , Criança , Etiópia , Política de Saúde , Humanos , Recém-Nascido , Formulação de Políticas
3.
Malar J ; 16(1): 344, 2017 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-28818071

RESUMO

BACKGROUND: Health facility-based data reported through routine health information systems form the primary data source for programmatic monitoring and evaluation in most developing countries. The adoption of District Health Information Software (DHIS2) has contributed to improved availability of routine health facility-based data in many low-income countries. An assessment of malaria indicators data reported by health facilities in Kenya during the first 5 years of implementation of DHIS2, from January 2011 to December 2015, was conducted. METHODS: Data on 19 malaria indicators reported monthly by health facilities were extracted from the online Kenya DHIS2 database. Completeness of reporting was analysed for each of the 19 malaria indicators and expressed as the percentage of data values actually reported over the expected number; all health facilities were expected to report data for each indicator for all 12 months in a year. RESULTS: Malaria indicators data were analysed for 6235 public and 3143 private health facilities. Between 2011 and 2015, completeness of reporting in the public sector increased significantly for confirmed malaria cases across all age categories (26.5-41.9%, p < 0.0001, in children aged <5 years; 30.6-51.4%, p < 0.0001, in persons aged ≥5 years). Completeness of reporting of new antenatal care (ANC) clients increased from 53.7 to 70.5%, p < 0.0001). Completeness of reporting of intermittent preventive treatment in pregnancy (IPTp) decreased from 64.8 to 53.7%, p < 0.0001 for dose 1 and from 64.6 to 53.4%, p < 0.0001 for dose 2. Data on malaria tests performed and test results were not available in DHIS2 from 2011 to 2014. In 2015, sparse data on microscopy (11.5% for children aged <5 years; 11.8% for persons aged ≥5 years) and malaria rapid diagnostic tests (RDTs) (8.1% for all ages) were reported. In the private sector, completeness of reporting increased significantly for confirmed malaria cases across all age categories (16.7-23.1%, p < 0.0001, in children aged <5 years; 19.4-28.6%, p < 0.0001, in persons aged ≥5 years). Completeness of reporting also improved for new ANC clients (16.2-23.6%, p < 0.0001), and for IPTp doses 1 and 2 (16.6-20.2%, p < 0.0001 and 15.5-20.5%, p < 0.0001, respectively). In 2015, less than 3% of data values for malaria tests performed were reported in DHIS2 from the private sector. CONCLUSIONS: There have been sustained improvements in the completeness of data reported for most key malaria indicators since the adoption of DHIS2 in Kenya in 2011. However, major data gaps were identified for the malaria-test indicator and overall low reporting across all indicators from private health facilities. A package of proven DHIS2 implementation interventions and performance-based incentives should be considered to improve private-sector data reporting.


Assuntos
Notificação de Doenças/estatística & dados numéricos , Sistemas de Informação em Saúde , Malária , Humanos , Quênia , Software
4.
Sci Rep ; 6: 19472, 2016 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-26846726

RESUMO

Serology has become an increasingly important tool for the surveillance of a wide range of infectious diseases. It has been particularly useful to monitor malaria transmission in elimination settings where existing metrics such as parasite prevalence and incidence of clinical cases are less sensitive. Seroconversion rates, based on antibody prevalence to Plasmodium falciparum asexual blood-stage antigens, provide estimates of transmission intensity that correlate with entomological inoculation rates but lack precision in settings where seroprevalence is still high. Here we present a new and widely applicable method, based on cross-sectional data on individual antibody levels. We evaluate its use as a sero-surveillance tool in a Tanzanian setting with declining malaria prevalence. We find that the newly developed mathematical models produce more precise estimates of transmission patterns, are robust in high transmission settings and when sample sizes are small, and provide a powerful tool for serological evaluation of malaria transmission intensity.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Malária Falciparum/imunologia , Malária Falciparum/transmissão , Plasmodium falciparum/imunologia , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Humanos , Incidência , Lactente , Vigilância da População , Prevalência , Estudos Soroepidemiológicos , Tanzânia/epidemiologia
5.
Infect Immun ; 84(4): 950-963, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26787721

RESUMO

Severe malaria (SM) is a life-threatening complication of infection with Plasmodium falciparum Epidemiological observations have long indicated that immunity against SM is acquired relatively rapidly, but prospective studies to investigate its immunological basis are logistically challenging and have rarely been undertaken. We investigated the merozoite targets and antibody-mediated mechanisms associated with protection against SM in Kenyan children aged 0 to 2 years. We designed a unique prospective matched case-control study of well-characterized SM clinical phenotypes nested within a longitudinal birth cohort of children (n= 5,949) monitored over the first 2 years of life. We quantified immunological parameters in sera collected before the SM event in cases and their individually matched controls to evaluate the prospective odds of developing SM in the first 2 years of life. Anti-AMA1 antibodies were associated with a significant reduction in the odds of developing SM (odds ratio [OR] = 0.37; 95% confidence interval [CI] = 0.15 to 0.90; P= 0.029) after adjustment for responses to all other merozoite antigens tested, while those against MSP-2, MSP-3, Plasmodium falciparum Rh2 [PfRh2], MSP-119, and the infected red blood cell surface antigens were not. The combined ability of total IgG to inhibit parasite growth and mediate the release of reactive oxygen species from neutrophils was associated with a marked reduction in the odds of developing SM (OR = 0.07; 95% CI = 0.006 to 0.82;P= 0.03). Assays of these two functional mechanisms were poorly correlated (Spearman rank correlation coefficient [rs] = 0.12;P= 0.07). Our data provide epidemiological evidence that multiple antibody-dependent mechanisms contribute to protective immunity via distinct targets whose identification could accelerate the development of vaccines to protect against SM.


Assuntos
Anticorpos Antiprotozoários/fisiologia , Malária Falciparum/imunologia , Plasmodium falciparum/fisiologia , Envelhecimento , Antígenos de Protozoários/imunologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Inibidores do Crescimento/metabolismo , Humanos , Lactente , Quênia/epidemiologia , Merozoítos/imunologia , Razão de Chances , Explosão Respiratória/fisiologia
6.
BMC Med ; 13: 114, 2015 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-25967134

RESUMO

BACKGROUND: Epidemiological studies indicate that some children experience many more episodes of clinical malaria than their age mates in a given location. Whether this is as a result of the micro-heterogeneity of malaria transmission with some children effectively getting more exposure to infectious mosquitoes than others, or reflects a failure in the acquisition of immunity needs to be elucidated. Here, we investigated the determinants of increased susceptibility to clinical malaria by comparing the intensity of exposure to Plasmodium falciparum and the acquisition of immunity in children at the extreme ends of the over-dispersed distribution of the incidence of clinical malaria. METHODS: The study was nested within a larger cohort in an area where the intensity of malaria transmission was low. We identified children who over a five-year period experienced 5 to 16 clinical malaria episodes (children at the tail-end of the over-dispersed distribution, n = 35), remained malaria-free (n = 12) or had a single episode (n = 26). We quantified antibodies against seven Plasmodium falciparum merozoite antigens in plasma obtained at six cross-sectional surveys spanning these five years. We analyzed the antibody responses to identify temporal dynamics that associate with disease susceptibility. RESULTS: Children experiencing multiple episodes of malaria were more likely to be parasite positive by microscopy at cross-sectional surveys (X (2) test for trend 14.72 P = 0.001) and had a significantly higher malaria exposure index, than those in the malaria-free or single episode groups (Kruskal-Wallis test P = 0.009). In contrast, the five-year temporal dynamics of anti-merozoite antibodies were similar in the three groups. Importantly in all groups, antibody levels were below the threshold concentrations previously observed to be correlated with protective immunity. CONCLUSIONS: We conclude that in the context of a low malaria transmission setting, susceptibility to clinical malaria is not accounted for by anti-merozoite antibodies but appears to be a consequence of increased parasite exposure. We hypothesize that intensive exposure is a prerequisite for protective antibody concentrations, while little to modest exposure may manifest as multiple clinical infections with low levels of antibodies. These findings have implications for interventions that effectively lower malaria transmission intensity.


Assuntos
Malária Falciparum/epidemiologia , Malária Falciparum/imunologia , Animais , Anticorpos Antiprotozoários/sangue , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Incidência , Lactente , Malária Falciparum/transmissão , Masculino , Plasmodium falciparum
7.
Clin Infect Dis ; 57(10): 1409-16, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23983244

RESUMO

BACKGROUND: Elucidating the mechanisms of naturally acquired immunity to Plasmodium falciparum infections would be highly valuable for malaria vaccine development. Asymptomatic multiclonal infections have been shown to predict protection from clinical malaria in a transmission-dependent manner, but the mechanisms underlying this are unclear. We assessed the breadth of antibody responses to several vaccine candidate merozoite antigens in relation to the infecting parasite population and clinical immunity. METHODS: In a cohort study in Tanzania, 320 children aged 1-16 years who were asymptomatic at baseline were included. We genotyped P. falciparum infections by targeting the msp2 gene using polymerase chain reaction and capillary electrophoresis and measured antibodies to 7 merozoite antigens using a multiplex assay. We assessed the correlation between the number of clones and the breadth of the antibody response, and examined their effects on the risk of malaria during 40 weeks of follow-up using age-adjusted multivariate regression models. RESULTS: The antibody breadth was positively correlated with the number of clones (RR [risk ratio], 1.63; 95% confidence interval [CI], 1.32-2.02). Multiclonal infections were associated with a nonsignificant reduction in the risk of malaria in the absence of antibodies (RR, 0.83; 95% CI, .29-2.34). The breadth of the antibody response was significantly associated with a reduced risk of malaria in the absence of infections (RR, 0.25; 95% CI, .09-.66). In combination, these factors were associated with a lower risk of malaria than they were individually (RR, 0.14; 95% CI, .04-.48). CONCLUSIONS: These data suggest that malaria vaccines mimicking naturally acquired immunity should ideally induce antibody responses that can be boosted by natural infections.


Assuntos
Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Malária Falciparum/imunologia , Malária Falciparum/parasitologia , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia , Adolescente , Anticorpos Antiprotozoários/biossíntese , Antígenos de Protozoários/genética , Infecções Assintomáticas , Criança , Pré-Escolar , Estudos de Coortes , Genótipo , Humanos , Lactente , Merozoítos/imunologia , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Risco , Tanzânia
8.
Eur J Immunol ; 43(11): 2919-29, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23881859

RESUMO

Antibodies (Abs) are critical for immunity to malaria. However, Plasmodium falciparum specific Abs decline rapidly in absence of reinfection, suggesting impaired immunological memory. This study determines whether residents of Sweden that were treated for malaria following international travel maintained long-lasting malaria-specific Abs and memory B cells (MBCs). We compared levels of malaria-specific Abs and MBCs between 47 travelers who had been admitted with malaria at the Karolinska University Hospital between 1 and 16 years previously, eight malaria-naïve adult Swedes without histories of travel, and 14 malaria-immune adult Kenyans. Plasmodium falciparum-lysate-specific Ab levels were above naïve control levels in 30% of the travelers, whereas AMA-1, merozoite surface protein-142 , and merozoite surface protein-3-specific Ab levels were similar. In contrast, 78% of travelers had IgG-MBCs specific for at least one malaria antigen (59, 45, and 28% for apical merozoite antigen-1, merozoite surface protein-1, and merozoite surface protein-3, respectively) suggesting that malaria-specific MBCs are maintained for longer than the cognate serum Abs in the absence of re-exposure to parasites. Five travelers maintained malaria antigen-specific MBC responses for up to 16 years since the diagnosis of the index episode (and had not traveled to malaria-endemic regions in the intervening time). Thus P. falciparum can induce long-lasting MBCs, maintained for up to 16 years without reexposure.


Assuntos
Anticorpos Antiprotozoários/imunologia , Linfócitos B/imunologia , Memória Imunológica/imunologia , Malária Falciparum/imunologia , Plasmodium falciparum/imunologia , Adulto , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Malária Falciparum/sangue , Malária Falciparum/parasitologia , Masculino , Proteínas de Membrana/imunologia , Proteína 1 de Superfície de Merozoito/imunologia , Merozoítos/imunologia , Proteínas de Protozoários/imunologia , Inquéritos e Questionários , Suécia , Viagem
9.
PLoS One ; 8(2): e56032, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23418502

RESUMO

Children in malaria endemic areas acquire immunity to severe malaria faster than to mild malaria. Only a minority of children suffers from severe malaria and it is not known what determines this. The aim of this study was to establish how P. falciparum infections during the first years of life affect the risk of severe malaria. A matched case-control study was nested within a large birth cohort set up to study the immunoepidemiology of pneumococci on the Kenyan coast. Infection patterns in three-monthly blood samples in cohort children admitted to hospital with severe malaria were compared to controls matched on age, residential location and time of sampling. P. falciparum detected at least once from birth conferred an increased risk of severe malaria and particularly if multiclonal infections, as characterized by genotyping of a polymorphic antigen gene, were ever detected. The results show for the first time that children with severe malaria have more infections early in life compared to community controls. These findings provide important insights on the immunity to severe disease, knowledge essential for the development of a vaccine against severe malaria.


Assuntos
Malária Falciparum/epidemiologia , Plasmodium falciparum/isolamento & purificação , Estudos de Casos e Controles , Pré-Escolar , Feminino , Humanos , Lactente , Quênia/epidemiologia , Malária Falciparum/imunologia , Masculino , Risco , Índice de Gravidade de Doença
10.
Malar J ; 11: 176, 2012 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-22632033

RESUMO

Artemether-lumefantrine is currently first-line therapy of Plasmodium falciparum malaria in many countries. This report describes a treatment failure despite adequate drug concentrations in a traveller returning from sub-Saharan Africa. Genotyping confirmed recrudescence and suggested reduced sensitivity. Potential sub-optimal effect of artemether-lumefantrine highlights the need to follow non-immune individuals the weeks after treatment.


Assuntos
Antimaláricos/administração & dosagem , Artemisininas/administração & dosagem , Etanolaminas/administração & dosagem , Fluorenos/administração & dosagem , Malária Falciparum/tratamento farmacológico , Viagem , Combinação Arteméter e Lumefantrina , Combinação de Medicamentos , Resistência a Medicamentos , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/classificação , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Recidiva , Tanzânia , Falha de Tratamento
11.
Infect Immun ; 80(5): 1900-8, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22392930

RESUMO

Plasmodium falciparum's ability to invade erythrocytes is essential for its survival within the human host. Immune mechanisms that impair this ability are therefore expected to contribute to immunity against the parasite. Plasma of humans who are naturally exposed to malaria has been shown to have growth-inhibitory activity (GIA) in vitro. However, the importance of GIA in relation to protection from malaria has been unclear. In a case-control study nested within a longitudinally followed population in Tanzania, plasma samples collected at baseline from 171 individuals (55 cases and 116 age-matched controls) were assayed for GIA using three P. falciparum lines (3D7, K1, and W2mef) chosen based on their erythrocyte invasion phenotypes. Distribution of GIA differed between the lines, with most samples inhibiting the growth of 3D7 and K1 and enhancing the growth of W2mef. GIA to 3D7 was associated with a reduced risk of malaria within 40 weeks of follow-up (odds ratio, 0.45; 95% confidence interval [CI], 0.21 to 0.96; P = 0.04), whereas GIA to K1 and W2mef was not. These results show that GIA, as well as its association with protection from malaria, is dependent on the P. falciparum line and can be explained by differences in erythrocyte invasion phenotypes between parasite lines. Our study contributes knowledge on the biological importance of growth inhibition and the potential influence of P. falciparum erythrocyte invasion phenotypic differences on its relationship to protective immunity against malaria.


Assuntos
Malária Falciparum/sangue , Malária Falciparum/parasitologia , Plasmodium falciparum/classificação , Adolescente , Adulto , Envelhecimento , Animais , Estudos de Casos e Controles , Criança , Feminino , Humanos , Malária Falciparum/epidemiologia , Masculino , Fatores de Risco , Tanzânia/epidemiologia , Adulto Jovem
12.
Antimicrob Agents Chemother ; 54(8): 3302-7, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20516285

RESUMO

Resistance to the amino alcohol quinine has been associated with polymorphisms in pfnhe, a sodium hydrogen exchanger. We investigated the role of this gene in quinine resistance in vitro in isolates from Kenya. We analyzed pfnhe whole-gene polymorphisms, using capillary sequencing, and pfcrt at codon 76 (pfcrt-76) and pfmdr1 at codon 86 (pfmdr1-86), using PCR-enzyme restriction methodology, in 29 isolates from Kilifi, Kenya, for association with the in vitro activities of quinine and 2 amino alcohols, mefloquine and halofantrine. In vitro activity was assessed as the drug concentration that inhibits 50% of parasite growth (IC50). The median IC50s of quinine, halofantrine, and mefloquine were 92, 22, and 18 nM, respectively. The presence of 2 DNNND repeats in microsatellite ms4760 of pfnhe was associated with reduced susceptibility to quinine (60 versus 227 nM for 1 and 2 repeats, respectively; P<0.05), while 3 repeats were associated with restoration of susceptibility. The decrease in susceptibility conferred by the 2 DNNND repeats was more pronounced in parasites harboring the pfmdr1-86 mutation. No association was found between susceptibility to quinine and the pfcrt-76 mutation or between susceptibility to mefloquine or halofantrine and the pfnhe gene and the pfcrt-76 and pfmdr1-86 mutations. Using previously published data on the in vitro activities of chloroquine, lumefantrine, piperaquine, and dihydroartemisinin, we investigated the association of their activities with pfnhe polymorphism. With the exception of a modulation of the activity of lumefantrine by a mutation at position 1437, pfnhe did not modulate their activities. Two DNNND repeats combined with the pfmdr1-86 mutation could be used as an indicator of reduced susceptibility to quinine.


Assuntos
Antimaláricos/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Polimorfismo Genético , Quinina/farmacologia , Trocadores de Sódio-Hidrogênio/genética , Sequência de Aminoácidos , Animais , Resistência a Medicamentos/genética , Humanos , Quênia , Mefloquina/farmacologia , Proteínas de Membrana Transportadoras , Dados de Sequência Molecular , Proteínas Associadas à Resistência a Múltiplos Medicamentos , Testes de Sensibilidade Parasitária , Fenantrenos/farmacologia , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Análise de Sequência de DNA , Trocadores de Sódio-Hidrogênio/química
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