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1.
J Glob Health ; 12: 04086, 2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-36227754

RESUMO

Background: Unmet needs for contraception constitute a major public health problem in sub-Saharan Africa. Several mechanisms have been tested to reduce the financial barrier and facilitate access to family planning services, with inconclusive results. Based on the positive impacts following the introduction of free health care for pregnant women, Burkina Faso decided to extend its national policy and abolished direct payment for family planning services. This study aims to evaluate the impact of this policy on contraceptive use and unmet needs for contraception among women of reproductive age (WRA) in Burkina Faso. Methods: This study uses two different study designs to examine the impact of a user fee removal policy on contraceptive use across a panel of 1400 households randomly selected across eight health districts. Data were collected using a standardized socio-demographic questionnaire at three different time points during the pilot and scale-up phases of the fee abolition program. The questionnaire was administered six months after the launch of the pilot fee abolition program in four health districts. For the remaining four health districts, the survey was conducted one year prior to and six months after the implementation of the program in those areas. All WRA in the households were eligible to participate. A cross-sectional study design was used to determine the association between knowledge of the fee abolition policy among WRA and actual use of contraceptives by WRA six months after the policy's implementation and across all eight districts. Additionally, a pre-post study with a non-randomized, reflexive control group was designed using repeated surveys in four health districts. Hierarchical logistic mixed effects models were adjusted for a set of time-variant individual variables; the impact was assessed by a difference-in-differences approach that compared pre-post changes in contraception use in women who knew about the new policy and those who did not. Results: Of the 1471 WRA surveyed six months after the removal of user fees for family planning services, 56% were aware of the policy's existence. Knowledge of the fee abolition policy was associated with a 46% increase probability of contraceptive use among WRA six months after the policy's implementation. Among the subset of the participants who were surveyed twice (n = 507), 65% knew about the fee removal policy six months after its introduction and constitute the intervention group. Pre-post changes in contraceptive use differed significantly between the intervention (n = 327) and control groups (n = 180). Removing user fees for family planning led to an 86% (95% confidence interval (CI) = 0.49, 1.31) increase in the likelihood of using contraception. In the study area, the policy reduced the prevalence of unmet needs for contraception by 13 percentage points. Conclusions: Removing user fees for family planning services is a promising strategy to increase access to, and reduce unmet needs for, contraception. A broader dissemination of the policy's existence will likely increase its impact on the overall population.


Assuntos
Anticoncepção , Serviços de Planejamento Familiar , Burkina Faso , Anticoncepcionais , Estudos Transversais , Feminino , Humanos , Políticas , Gravidez
2.
J Infect Dis ; 226(8): 1461-1469, 2022 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-35711005

RESUMO

Serological data can provide estimates of human exposure to both malaria vector and parasite based on antibody responses. A multiplex bead-based assay was developed to simultaneously detect IgG to Anopheles albimanus salivary gland extract (SGE) and 23 Plasmodium falciparum antigens among 4185 participants enrolled in Artibonite department, Haiti in 2017. Logistic regression adjusted for participant- and site-level covariates and found children under 5 years and 6-15 years old had 3.7- and 5.4-fold increase in odds, respectively, of high anti-SGE IgG compared to participants >15 years. Seropositivity to P. falciparum CSP, Rh2_2030, and SEA-1 antigens was significantly associated with high IgG response against SGE, and participant enrolment at elevations under 200 m was associated with higher anti-SGE IgG levels. The ability to approximate population exposure to malaria vectors through SGE serology data is very dependent by age categories, and SGE antigens can be easily integrated into a multiplex serological assay.


Assuntos
Anopheles , Malária Falciparum , Malária , Animais , Anopheles/parasitologia , Formação de Anticorpos , Antígenos , Criança , Pré-Escolar , Haiti/epidemiologia , Humanos , Imunoglobulina G , Malária/epidemiologia , Malária Falciparum/epidemiologia , Mosquitos Vetores , Plasmodium falciparum , Glândulas Salivares
3.
FASEB J ; 36(5): e22279, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35344219

RESUMO

Ornithine decarboxylase (ODC; EC 4.1.1.17) catalyzes the conversion of ornithine to putrescine, the rate-limiting first step for de novo polyamine biosynthesis. Previously, we reported that genetic knockdown of xanthine dehydrogenase 1 (XDH1)-a gene encoding the enzyme involved in the last two steps of uric acid synthesis-causes an increase in ODC transcript levels in fat body of blood-fed Aedes aegypti mosquitoes, suggesting a crosstalk at molecular level between XDH1 and ODC during nitrogen disposal. To further investigate the role of ODC in nitrogen metabolism, we conducted several biochemical and genetic analyses in sugar- and blood-fed A. aegypti females. Distinct ODC gene and protein expression patterns were observed in mosquito tissues dissected during the first gonotrophic cycle. Both pharmacological and RNA interference-mediated knockdown of ODC negatively impacted mosquito survival, disrupted nitrogen waste disposal, delayed oviposition onset, and decreased fecundity in vitellogenic blood-fed females. A lag in the expression of two major digestive serine proteases, a reduction of blood meal digestion in the midgut, and a decrease in vitellogenin yolk protein uptake in ovarian follicles were observed by western blots in ODC-deficient females. Moreover, genetic silencing of ODC showed a broad transcriptional modulation of genes encoding proteins involved in multiple metabolic pathways in mosquito fat body, midgut, and Malpighian tubules prior to and after blood feeding. All together, these data demonstrate that ODC plays an essential role in mosquito metabolism, and that ODC crosstalks with multiple genes and proteins to prevent deadly nitrogen perturbations in A. aegypti females.


Assuntos
Aedes , Animais , Feminino , Nitrogênio/metabolismo , Ornitina , Ornitina Descarboxilase/genética , Oviposição
4.
J Infect Dis ; 225(9): 1611-1620, 2022 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33993294

RESUMO

BACKGROUND: Haiti is planning targeted interventions to accelerate progress toward malaria elimination. In the most affected department (Grande-Anse), a combined mass drug administration (MDA) and indoor residual spraying (IRS) campaign was launched in October 2018. This study assessed the intervention's effectiveness in reducing Plasmodium falciparum prevalence. METHODS: An ecological quasi-experimental study was designed, using a pretest and posttest with a nonrandomized control group. Surveys were conducted in November 2017 in a panel of easy access groups (25 schools and 16 clinics) and were repeated 2-6 weeks after the campaign, in November 2018. Single-dose sulfadoxine-pyrimethamine and primaquine was used for MDA, and pirimiphos-methyl as insecticide for IRS. RESULTS: A total of 10 006 participants were recruited. Fifty-two percent of the population in the intervention area reported having received MDA. Prevalence diminished between 2017 and 2018 in both areas, but the reduction was significantly larger in the intervention area (ratio of adjusted risk ratios, 0.32 [95% confidence interval, .104-.998]). CONCLUSIONS: Despite a moderate coverage, the campaign was effective in reducing P. falciparum prevalence immediately after 1 round. Targeted MDA plus IRS is useful in preelimination settings to rapidly decrease the parasite reservoir, an encouraging step to accelerate progress toward malaria elimination.


Assuntos
Inseticidas , Malária , Haiti/epidemiologia , Humanos , Inseticidas/farmacologia , Malária/tratamento farmacológico , Malária/epidemiologia , Malária/prevenção & controle , Administração Massiva de Medicamentos , Controle de Mosquitos
5.
Am J Trop Med Hyg ; 104(6): 2139-2145, 2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33819177

RESUMO

Haiti is targeting malaria elimination by 2025. The Grand'Anse department in southwestern Haiti experiences one-third to half of all nationally reported Plasmodium falciparum cases. Although there are historical reports of Plasmodium vivax and Plasmodium malariae, today, non-falciparum infections would remain undetected because of extensive use of falciparum-specific histidine-rich protein 2 (HRP2) rapid diagnostic tests (RDT) at health facilities. A recent case-control study was conducted in Grand'Anse to identify risk factors for P. falciparum infection using HRP2-based RDTs (n = 1,107). Post hoc multiplex Plasmodium antigenemia and antibody (IgG) detection by multiplex bead assay revealed one blood sample positive for pan-Plasmodium aldolase, negative for P. falciparum HRP2, and positive for IgG antibodies to P. malariae. Based on this finding, we selected 52 samples with possible P. malariae infection using IgG and antigenemia data and confirmed infection status by species-specific PCR. We confirmed one P. malariae infection in a 6-month-old infant without travel history. Congenital P. malariae could not be excluded. However, our finding-in combination with historical reports of P. malariae-warrants further investigation into the presence and possible extent of non-falciparum malaria in Haiti. Furthermore, we showed the use of multiplex Plasmodium antigen and IgG detection in selecting samples of interest for subsequent PCR analysis, thereby reducing costs as opposed to testing all available samples by PCR. This is of specific use in low-transmission or eliminating settings where infections are rare.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/sangue , Erradicação de Doenças/métodos , Malária/diagnóstico , Malária/prevenção & controle , Programas de Rastreamento/métodos , Plasmodium malariae/imunologia , Proteínas de Protozoários/sangue , Adolescente , Antígenos de Protozoários/imunologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Erradicação de Doenças/normas , Haiti/epidemiologia , Humanos , Imunoglobulina G/sangue , Lactente , Malária/epidemiologia , Malária/imunologia , Programas de Rastreamento/estatística & dados numéricos , Plasmodium malariae/química , Plasmodium malariae/genética , Proteínas de Protozoários/imunologia
6.
Front Immunol ; 11: 928, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32499783

RESUMO

In our aim to eliminate malaria, more sensitive tools to detect residual transmission are quickly becoming essential. Antimalarial antibody responses persist in the blood after a malaria infection and provide a wider window to detect exposure to infection compared to parasite detection metrics. Here, we aimed to select antibody responses associated with recent and cumulative exposure to malaria using cross-sectional survey data from Haiti, an elimination setting. Using a multiplex bead assay, we generated data for antibody responses (immunoglobulin G) to 23 Plasmodium falciparum targets in 29,481 participants across three surveys. This included one community-based survey in which participants were enrolled during household visits and two sentinel group surveys in which participants were enrolled at schools and health facilities. First, we correlated continuous antibody responses with age (Spearman) to determine which showed strong age-related associations indicating accumulation over time with limited loss. AMA-1 and MSP-119 antibody levels showed the strongest correlation with age (0.47 and 0.43, p < 0.001) in the community-based survey, which was most representative of the underlying age structure of the population, thus seropositivity to either of these antibodies was considered representative of cumulative exposure to malaria. Next, in the absence of a gold standard for recent exposure, we included antibody responses to the remaining targets to predict highly sensitive rapid diagnostic test (hsRDT) status using receiver operating characteristic curves. For this, only data from the survey with the highest hsRDT prevalence was used (7.2%; 348/4,849). The performance of the top two antigens in the training dataset (two-thirds of the dataset; n = 3,204)-Etramp 5 ag 1 and GLURP-R0 (area-under-the-curve, AUC, 0.892 and 0.825, respectively)-was confirmed in the test dataset (remaining one-third of the dataset; n = 1,652, AUC 0.903 and 0.848, respectively). As no further improvement was seen by combining seropositivity to GLURP-R0 and Etramp 5 ag 1 (p = 0.266), seropositivity to Etramp 5 ag 1 alone was selected as representative of current or recent exposure to malaria. The validation of antibody responses associated with these exposure histories simplifies analyses and interpretation of antibody data and facilitates the application of results to evaluate programs.


Assuntos
Anticorpos Antiprotozoários/sangue , Formação de Anticorpos , Malária Falciparum/imunologia , Plasmodium falciparum/imunologia , Adolescente , Adulto , Fatores Etários , Anticorpos Antiprotozoários/imunologia , Criança , Estudos Transversais , Erradicação de Doenças , Haiti , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Prevalência , Adulto Jovem
7.
BMC Med ; 18(1): 141, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32571323

RESUMO

BACKGROUND: As in most eliminating countries, malaria transmission is highly focal in Haiti. More granular information, including identifying asymptomatic infections, is needed to inform programmatic efforts, monitor intervention effectiveness, and identify remaining foci. Easy access group (EAG) surveys can supplement routine surveillance with more granular information on malaria in a programmatically tractable way. This study assessed how and which type of venue for EAG surveys can improve understanding malaria epidemiology in two regions with different transmission profiles. METHODS: EAG surveys were conducted within the departments of Artibonite and Grand'Anse (Haiti), in regions with different levels of transmission intensity. Surveys were conducted in three venue types: primary schools, health facilities, and churches. The sampling approach varied accordingly. Individuals present at the venues at the time of the survey were eligible whether they presented malaria symptoms or not. The participants completed a questionnaire and were tested for Plasmodium falciparum by a highly sensitive rapid diagnostic test (hsRDT). Factors associated with hsRDT positivity were assessed by negative binomial random-effects regression models. RESULTS: Overall, 11,029 individuals were sampled across 39 venues in Artibonite and 41 in Grand'Anse. The targeted sample size per venue type (2100 in Artibonite and 2500 in Grand'Anse) was reached except for the churches in Artibonite, where some attendees left the venue before they could be approached or enrolled. Refusal rate and drop-out rate were < 1%. In total, 50/6003 (0.8%) and 355/5026 (7.1%) sampled individuals were hsRDT positive in Artibonite and Grand'Anse, respectively. Over half of all infections in both regions were identified at health facilities. Being male and having a current or reported fever in the previous 2 weeks were consistently identified with increased odds of being hsRDT positive. CONCLUSIONS: Surveys in churches were problematic because of logistical and recruitment issues. However, EAG surveys in health facilities and primary schools provided granular information about malaria burden within two departments in Haiti. The EAG surveys were able to identify residual foci of transmission that were missed by recent national surveys. Non-care seeking and/or asymptomatic malaria infections can be identified in this alternative surveillance tool, facilitating data-driven decision-making for improved targeting of interventions.


Assuntos
Surtos de Doenças/estatística & dados numéricos , Monitoramento Epidemiológico , Malária Falciparum/epidemiologia , Plasmodium falciparum/patogenicidade , Adolescente , Adulto , Criança , Feminino , Haiti/epidemiologia , Humanos , Masculino , Adulto Jovem
8.
Am J Trop Med Hyg ; 103(2): 767-777, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32458784

RESUMO

The island of Hispaniola aims to eliminate malaria by 2025; however, there are limited data to describe epidemiologic risk factors for malaria in this setting. A prospective case-control study was conducted at four health facilities in southwest Haiti, aiming to describe factors influencing the risk of current and past malaria infection. Cases were defined as individuals attending facilities with current or recent fever and positive malaria rapid diagnostic test (RDT), while controls were those with current or recent fever and RDT negative. Serological markers of recent and cumulative exposure to Plasmodium were assessed using the multiplex bead assay from dried blood spots and used for alternate case definitions. Kuldorff's spatial scan statistic was used to identify local clusters of infection or exposure. Logistic regression models were used to assess potential risk factors for RDT positivity and recent exposure markers, including age-group, gender, and recruiting health facility as group-matching variables. A total of 192 cases (RDT positive) and 915 controls (RDT negative) were recruited. Consistent spatial clusters were identified for all three infection and exposure metrics, indicating temporal stability of malaria transmission at these sites. Risk factors included remoteness from health facilities and household construction, furthermore, insecticide-treated net ownership or use was associated with reduced odds of RDT positivity. These findings indicate the malaria risk in Grand'Anse is driven primarily by location. Travel, occupation, and other behavioral factors were not associated with malaria. These data can support the National Malaria Program to refine and target their intervention approaches, and to move toward elimination.


Assuntos
Anticorpos Antiprotozoários/imunologia , Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Malária Falciparum/epidemiologia , Controle de Mosquitos/estatística & dados numéricos , Plasmodium falciparum/imunologia , Adolescente , Adulto , Fatores Etários , Estudos de Casos e Controles , Criança , Pré-Escolar , Materiais de Construção , Fazendeiros , Feminino , Febre , Haiti/epidemiologia , Instalações de Saúde , Habitação , Humanos , Malária Falciparum/imunologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Estudantes , Adulto Jovem
9.
Sci Rep ; 10(1): 1135, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31980693

RESUMO

Measuring antimalarial antibodies can estimate transmission in a population. To compare outputs, standardized laboratory testing is required. Here we describe the in-country establishment and quality control (QC) of a multiplex bead assay (MBA) for three sero-surveys in Haiti. Total IgG data against 21 antigens were collected for 32,758 participants. Titration curves of hyperimmune sera were included on assay plates, assay signals underwent 5-parameter regression, and inspection of the median and interquartile range (IQR) for the y-inflection point was used to determine assay precision. The medians and IQRs were similar for Surveys 1 and 2 for most antigens, while the IQRs increased for some antigens in Survey 3. Levey-Jennings charts for selected antigens provided a pass/fail criterion for each assay plate and, of 387 assay plates, 13 (3.4%) were repeated. Individual samples failed if IgG binding to the generic glutathione-S-transferase protein was observed, with 659 (2.0%) samples failing. An additional 455 (1.4%) observations failed due to low bead numbers (<20/analyte). The final dataset included 609,438 anti-malaria IgG data points from 32,099 participants; 96.6% of all potential data points if no QC failures had occurred. The MBA can be deployed with high-throughput data collection and low inter-plate variability while ensuring data quality.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Imunoglobulina G/sangue , Separação Imunomagnética/métodos , Malária Falciparum/diagnóstico , Plasmodium falciparum/imunologia , Controle de Qualidade , Testes Sorológicos/métodos , Anticorpos Antiprotozoários/imunologia , Especificidade de Anticorpos , Estudos Transversais , Conjuntos de Dados como Assunto , Haiti/epidemiologia , Humanos , Imunoglobulina G/imunologia , Separação Imunomagnética/instrumentação , Malária Falciparum/sangue , Malária Falciparum/epidemiologia , Malária Falciparum/imunologia , Proteínas Recombinantes/imunologia , Padrões de Referência , Reprodutibilidade dos Testes
10.
J Infect Dis ; 221(5): 786-795, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-31630194

RESUMO

Accurate malaria diagnosis is foundational for control and elimination, and Haiti relies on histidine-rich protein 2 (HRP2)-based rapid diagnostic tests (RDTs) identifying Plasmodium falciparum in clinical and community settings. In 2017, 1 household and 2 easy-access group surveys tested all participants (N = 32 506) by conventional and high-sensitivity RDTs. A subset of blood samples (n = 1154) was laboratory tested for HRP2 by bead-based immunoassay and for P. falciparum 18S rDNA by photo-induced electron transfer polymerase chain reaction. Both RDT types detected low concentrations of HRP2 with sensitivity estimates between 2.6 ng/mL and 14.6 ng/mL. Compared to the predicate HRP2 laboratory assay, RDT sensitivity ranged from 86.3% to 96.0% between tests and settings, and specificity from 90.0% to 99.6%. In the household survey, the high-sensitivity RDT provided a significantly higher number of positive tests, but this represented a very small proportion (<0.2%) of all participants. These data show that a high-sensitivity RDT may have limited utility in a malaria elimination setting like Haiti.


Assuntos
Testes Diagnósticos de Rotina/métodos , Malária Falciparum/diagnóstico , Malária Falciparum/transmissão , Plasmodium falciparum/genética , Plasmodium falciparum/imunologia , Adolescente , Antígenos de Protozoários/sangue , Antígenos de Protozoários/imunologia , Criança , Pré-Escolar , DNA de Protozoário/sangue , DNA de Protozoário/genética , DNA Ribossômico/sangue , DNA Ribossômico/genética , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Haiti/epidemiologia , Humanos , Lactente , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Masculino , Reação em Cadeia da Polimerase/métodos , Proteínas de Protozoários/sangue , Proteínas de Protozoários/imunologia , Sensibilidade e Especificidade
11.
Malar J ; 18(1): 402, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31801556

RESUMO

BACKGROUND: Serological data indicating the presence and level of antibodies against infectious disease antigens provides indicators of exposure and transmission patterns in a population. Laboratory testing for large-scale serosurveys is often hindered by time-consuming immunoassays that employ multiple tandem steps. Some nations have recently begun using malaria serosurveillance data to make inferences about the malaria exposure in their populations, and serosurveys have grown increasingly larger as more accurate estimates are desired. Presented here is a novel approach of antibody detection using bead-based immunoassay that involves incubating all assay reagents concurrently overnight. RESULTS: A serosurvey in was performed in Haiti in early 2017 with both sera (n = 712) and dried blood spots (DBS, n = 796) collected for the same participants. The Luminex® multiplex bead-based assay (MBA) was used to detect total IgG against 8 malaria antigens: PfMSP1, PvMSP1, PmMSP1, PfCSP, PfAMA1, PfLSA1, PfGLURP-R0, PfHRP2. All sera and DBS samples were assayed by MBA using a standard immunoassay protocol with multiple steps, as well a protocol where sample and all reagents were incubated together overnight-termed here the OneStep assay. When compared to a standard multi-step assay, this OneStep assay amplified the assay signal for IgG detection for all 8 malaria antigens. The greatest increases in assay signal were seen at the low- and mid-range IgG titers and were indicative of an enhancement in the analyte detection, not simply an increase in the background signal of the assay. Seroprevalence estimates were generally similar for this sample Haitian population for all antigens regardless of serum or DBS sample type or assay protocol used. CONCLUSIONS: When using the MBA for IgG detection, overnight incubation for the test sample and all assay reagents greatly minimized hands-on time for laboratory staff. Enhanced IgG signal was observed with the OneStep assay for all 8 malaria antigens employed in this study, and seroprevalence estimates for this sample population were similar regardless of assay protocol used. This overnight incubation protocol has the potential to be deployed for large-scale malaria serosurveys for the high-throughput and timely collection of antibody data, particularly for malaria seroprevalence estimates.


Assuntos
Imunoensaio/métodos , Malária/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Teste em Amostras de Sangue Seco , Feminino , Haiti/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Soroepidemiológicos , Adulto Jovem
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