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1.
PLOS Glob Public Health ; 3(12): e0001690, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38051697

RESUMO

Diabetes mellitus is a serious global health issue which significantly impacts public health and socioeconomic development. Exploring how the community perceives the causes of death and their associated risk factors is crucial for public health. This study combines verbal autopsy (VA) with the Type 2 Diabetes Mellitus (T2DM) register to explore community perceptions of causes of death and associated influential factors in Makkah province, Saudi Arabia. 302 VA interviews were conducted with relatives or caregivers of deceased who died between 2018 and 2021 based on T2DM medical register from Alnoor Specialist Hospital in Makkah City, Saudi Arabia. Cause-specific mortality fractions (CSMFs) obtained from the VA using the InterVA-5 model were utilized to assess community perception. We used a multivariable logistic regression model to determine factors influencing community perceptions of causes of death. Lin's CCC with 95% CI was used to analyze the concordance for the CSMFs from verbal autopsy causes of death (VACoD) as a presumed reference standard and family-reported causes of death (FRCoD). The outcomes of this study demonstrate a generally broad spectrum of community perceived mortalities, with some critical misconceptions based on the type of death and other vital events like marital status, with an overall CCC of 0.60 (95% CI: 0.20-1.00; p = 003). The study findings demonstrate that community perception is weak if the deceased was male compared to female (aOR: 0.52; 95% CI: 0.26-1.03) and if the deceased was > = 80 years compared to 34-59 years (aOR: 0.48; 95% CI: 0.16-1.38), but it significantly improves among married compared to single (aOR: 2.13; 95% CI: 1.02-4.42). Exploring community perception of causes of death is crucial as it provides valuable insights into the community's understanding, beliefs, and concerns regarding mortality. Higher or lower community perception is attributed to how people may perceive risk factors associated with the causes of death, which can guide public health planning and interventional programs. The study findings further emphasize the need to employ robust and standardized VA methods within the routine medical services for a systemized assessment of families' reported causes of death.

2.
BMC Womens Health ; 23(1): 609, 2023 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-37974142

RESUMO

BACKGROUND: Unsafe abortion is a major contributor to maternal morbidity and mortality in countries where induced abortion is restricted. In Kurdistan Region of Iraq, induced abortion is strictly forbidden except for life-threatening situations, increasing the risk of seeking unsafe abortions. Attitudes among healthcare professionals who directly encounter cases and consequences of induced abortion can be studied to improve women's access to safe abortion. This study aimed to examine attitudes towards induced abortion among gynecologists in Kurdistan Region of Iraq. METHODS: This cross-sectional facility-based study was conducted in the first quarter of 2022 in Kurdistan Region of Iraq in the cities of Erbil, Sulaymaniyah, and Duhok. Convenient sampling was used to invite 330 gynecologists to participate, with 171 ultimately completing the questionnaire, giving a response rate of 53%. Questionaries using the Taylor and Whitehead abortion attitude scale were sent in person or digitally. The data was then analyzed using Chi-square and Fisher's exact tests to determine the independence of attitudes and associations between attitudes and sociodemographic factors. RESULTS: Among 171 gynecologists, 25% of the gynecologists agreed that induced abortion is unacceptable under any circumstances. Most (71%) disagreed that a woman has the right to choose to have an induced abortion. Around 51% considered induced abortion murder, and 41% agreed that induced abortion goes against all morals. Around 57% disagreed with the legalization of induced abortion, while 43% agreed. Gynecologists who were unmarried (P = 0.025), under the age of 40 (P = 0.044), and with less than 10 years of clinical experience (P = 0.043) were more likely to support the legalization of induced abortion in Kurdistan Region. None of the variables was found to be independently associated with attitudes towards abortion legalization. CONCLUSIONS: Despite some younger gynecologists having more favorable attitudes towards induced abortion, most gynecologists in Kurdistan Region had less favorable views. Most gynecologists were willing to provide post-abortion care regardless of their legal status. We recommend conducting more studies to investigate the consequences of current abortion legislation among women in need of induced abortion in Kurdistan Region of Iraq.


Assuntos
Aborto Induzido , Aborto Espontâneo , Gravidez , Feminino , Humanos , Ginecologista , Iraque , Estudos Transversais , Conhecimentos, Atitudes e Prática em Saúde , Aborto Legal
3.
BMC Infect Dis ; 22(1): 925, 2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-36496395

RESUMO

BACKGROUND: The World Health Organization recommends pneumococcal vaccination (PCV) in the first year of life. We investigated pneumococcal serotypes in children with clinical or radiologically confirmed pneumonia and healthy controls prior to PCV13 vaccine introduction in Zanzibar. METHODS: Children (n = 677) with non-severe acute febrile illness aged 2-59 months presenting to a health centre in Zanzibar, Tanzania April-July 2011 were included. Nasopharyngeal swabs collected at enrolment were analysed by real-time PCR to detect and quantify pneumococcal serotypes in patients (n = 648) and in healthy asymptomatic community controls (n = 161). Children with clinical signs of pneumonia according to the Integrated Management of Childhood illness guidelines ("IMCI pneumonia") were subjected to a chest-X-ray. Consolidation on chest X-ray was considered "radiological pneumonia". RESULTS: Pneumococcal DNA was detected in the nasopharynx of 562/809 (69%) children (70% in patients and 64% in healthy controls), with no significant difference in proportions between patients with or without presence of fever, malnutrition, IMCI pneumonia or radiological pneumonia. The mean pneumococcal concentration was similar in children with and without radiological pneumonia (Ct value 26.3 versus 27.0, respectively, p = 0.3115). At least one serotype could be determined in 423 (75%) participants positive for pneumococci of which 33% had multiple serotypes detected. A total of 23 different serotypes were identified. One serotype (19F) was more common in children with fever (86/648, 13%) than in healthy controls (12/161, 7%), (p = 0.043). Logistic regression adjusting for age and gender showed that serotype 9A/V [aOR = 10.9 (CI 2.0-60.0, p = 0.006)] and 14 [aOR = 3.9 (CI 1.4-11.0, p = 0.012)] were associated with radiological pneumonia. The serotypes included in the PCV13 vaccine were found in 376 (89%) of the 423 serotype positive participants. CONCLUSION: The PCV13 vaccine introduced in 2012 targets a great majority of the identified serotypes. Infections with multiple serotypes are common. PCR-determined concentrations of pneumococci in nasopharynx were not associated with radiologically confirmed pneumonia. Trial registration Clinicaltrials.gov (NCT01094431).


Assuntos
Infecções Pneumocócicas , Pneumonia , Pré-Escolar , Humanos , Lactente , Infecções Pneumocócicas/prevenção & controle , Portador Sadio , Vacinas Pneumocócicas , Streptococcus pneumoniae/genética , Sorogrupo , Nasofaringe , Febre , Vacinas Conjugadas
4.
Pediatr Infect Dis J ; 37(7): 643-648, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29889810

RESUMO

BACKGROUND: New molecular methods have revealed frequent and often polymicrobial respiratory infections in children in low-income settings. It is not known whether presence of multiple pathogens is due to prolonged infections or to frequent exposure. The aim of this study was to analyze short-term pathogen clearance from nasopharynx and the rate of new respiratory tract infections in febrile preschool children. METHODS: Children (n = 207) with uncomplicated acute febrile illness 2-59 months of age presenting to a health center in Zanzibar, Tanzania, April-July 2011, were included. Paired nasopharyngeal swab samples, collected at enrolment and after 14 days, were analyzed by multiple real-time polymerase chain reaction for Adenovirus, bocavirus, Bordetella pertussis, Chlamydophila pneumoniae, Coronaviruses, Enterovirus, influenza A and B virus, metapneumovirus, measles virus, Mycoplasma pneumoniae, parainfluenza virus, Parechovirus, respiratory syncytial virus and Rhinovirus. An age-matched and geographically matched healthy control group (n = 166) underwent nasopharyngeal sampling on 1 occasion. RESULTS: At baseline, 157/207 (76%) patients had at least 1 pathogen detected, in total 199 infections. At follow-up (day 14), 162/199 (81%) of these infections were not detected, including >95% of the previously detected infections with Enterovirus, influenza A virus, influenza B virus, metapneumovirus or parainfluenza virus. Still 115 (56%) children were positive for at least 1 pathogen at follow-up, of which 95/115 (83%) were not found at baseline. Detection of influenza B on day 14 was significantly associated with fever during follow-up. CONCLUSION: The results suggest that children with acute febrile illness in Zanzibar rapidly clear respiratory tract infections but frequently acquire new infections within 14 days.


Assuntos
Febre/etiologia , Mycoplasma pneumoniae/isolamento & purificação , Nasofaringe/microbiologia , Nasofaringe/virologia , Infecções Respiratórias/diagnóstico , Vírus/isolamento & purificação , Pré-Escolar , Coinfecção/diagnóstico , Feminino , Febre/diagnóstico , Humanos , Lactente , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Estudos Longitudinais , Masculino , Reação em Cadeia da Polimerase Multiplex , Mycoplasma pneumoniae/genética , Estudos Prospectivos , Vírus Sincicial Respiratório Humano/genética , Vírus Sincicial Respiratório Humano/isolamento & purificação , Infecções Respiratórias/microbiologia , Infecções Respiratórias/virologia , Rhinovirus/genética , Rhinovirus/isolamento & purificação , Tanzânia/epidemiologia , Vírus/genética
5.
Clin Infect Dis ; 65(8): 1371-1377, 2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-29017253

RESUMO

Background: Acute infectious gastroenteritis is an important cause of illness and death among children in low-income countries. In addition to rotavirus vaccination, actions to improve nutrition status, sanitation, and water quality are important to reduce enteric infections, which are frequent also among asymptomatic children. The aim of this study was to investigate if the high prevalence of these infections reflects that they often are not cleared properly by the immune response or rather is due to frequent pathogen exposure. Methods: Rectal swabs were collected at time of acute diarrhea and 14 days later from 127 children, aged 2-59 months and living in rural Zanzibar, and were analyzed by real-time polymerase chain reaction targeting multiple pathogens. Results: At baseline, detection rates >20% were found for each of enterotoxigenic Escherichia coli, Shigella, Campylobacter, Cryptosporidium, norovirus GII, and adenovirus. At follow-up, a large proportion of the infections had become cleared (34-100%), or the pathogen load reduced, and this was observed also for agents that were presumably unrelated to diarrhea. Still, the detection frequencies at follow-up were for most agents as high as at baseline, because new infections had been acquired. Neither clearance nor reinfection was associated with moderate malnutrition, which was present in 21% of the children. Conclusions: Children residing in poor socioeconomic conditions, as in Zanzibar, are heavily exposed to enteric pathogens, but capable of rapidly clearing causative and coinfecting pathogens.


Assuntos
Diarreia , Gastroenterite , Bactérias/genética , Pré-Escolar , Estudos de Coortes , Cryptosporidium/genética , Diarreia/epidemiologia , Diarreia/microbiologia , Fezes/virologia , Gastroenterite/epidemiologia , Gastroenterite/microbiologia , Humanos , Lactente , Reação em Cadeia da Polimerase , Recidiva , Fatores Socioeconômicos , Tanzânia/epidemiologia , Vírus/genética
6.
Am J Trop Med Hyg ; 97(4): 1170-1179, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28820705

RESUMO

Since 2010, the World Health Organization has been recommending that all suspected cases of malaria be confirmed with parasite-based diagnosis before treatment. These guidelines represent a paradigm shift away from presumptive antimalarial treatment of fever. Malaria rapid diagnostic tests (mRDTs) are central to implementing this policy, intended to target artemisinin-based combination therapies (ACT) to patients with confirmed malaria and to improve management of patients with nonmalarial fevers. The ACT Consortium conducted ten linked studies, eight in sub-Saharan Africa and two in Afghanistan, to evaluate the impact of mRDT introduction on case management across settings that vary in malaria endemicity and healthcare provider type. This synthesis includes 562,368 outpatient encounters (study size range 2,400-432,513). mRDTs were associated with significantly lower ACT prescription (range 8-69% versus 20-100%). Prescribing did not always adhere to malaria test results; in several settings, ACTs were prescribed to more than 30% of test-negative patients or to fewer than 80% of test-positive patients. Either an antimalarial or an antibiotic was prescribed for more than 75% of patients across most settings; lower antimalarial prescription for malaria test-negative patients was partly offset by higher antibiotic prescription. Symptomatic management with antipyretics alone was prescribed for fewer than 25% of patients across all scenarios. In community health worker and private retailer settings, mRDTs increased referral of patients to other providers. This synthesis provides an overview of shifts in case management that may be expected with mRDT introduction and highlights areas of focus to improve design and implementation of future case management programs.


Assuntos
Testes Diagnósticos de Rotina/métodos , Febre/diagnóstico , Malária/diagnóstico , Afeganistão/epidemiologia , África Subsaariana/epidemiologia , Antimaláricos/uso terapêutico , Administração de Caso , Humanos , Malária/tratamento farmacológico , Malária/epidemiologia
7.
BMJ Open ; 7(3): e012973, 2017 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-28274962

RESUMO

OBJECTIVES: The overuse of antimalarial drugs is widespread. Effective methods to improve prescribing practice remain unclear. We evaluated the impact of 10 interventions that introduced rapid diagnostic tests for malaria (mRDTs) on the use of tests and adherence to results in different contexts. DESIGN: A comparative case study approach, analysing variation in outcomes across different settings. SETTING: Studies from the ACT Consortium evaluating mRDTs with a range of supporting interventions in 6 malaria endemic countries. Providers were governmental or non-governmental healthcare workers, private retail sector workers or community volunteers. Each study arm in a distinct setting was considered a case. PARTICIPANTS: 28 cases from 10 studies were included, representing 148 461 patients seeking care for suspected malaria. INTERVENTIONS: The interventions included different mRDT training packages, supervision, supplies and community sensitisation. OUTCOME MEASURES: Analysis explored variation in: (1) uptake of mRDTs (% febrile patients tested); (2) provider adherence to positive mRDTs (% Plasmodium falciparum positive prescribed/given Artemisinin Combination Treatment); (3) provider adherence to negative mRDTs (% P. falciparum negative not prescribed/given antimalarial). RESULTS: Outcomes varied widely across cases: 12-100% mRDT uptake; 44-98% adherence to positive mRDTs; 27-100% adherence to negative mRDTs. Providers appeared more motivated to perform well when mRDTs and intervention characteristics fitted with their own priorities. Goodness of fit of mRDTs with existing consultation and diagnostic practices appeared crucial to maximising the impact of mRDTs on care, as did prior familiarity with malaria testing; adequate human resources and supplies; possible alternative treatments for mRDT-negative patients; a more directive intervention approach and local preferences for ACTs. CONCLUSIONS: Basic training and resources are essential but insufficient to maximise the potential of mRDTs in many contexts. Programme design should respond to assessments of provider priorities, expectations and capacities. As mRDTs become established, the intensity of supporting interventions required seems likely to reduce.


Assuntos
Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Pessoal de Saúde/educação , Malária/diagnóstico , Malária/tratamento farmacológico , Padrões de Prática Médica , Gerenciamento Clínico , Prescrições de Medicamentos , Febre/diagnóstico , Fidelidade a Diretrizes/estatística & dados numéricos , Humanos , Plasmodium falciparum , Uso Excessivo de Medicamentos Prescritos/prevenção & controle , Kit de Reagentes para Diagnóstico/estatística & dados numéricos , Testes Sorológicos , Fatores de Tempo
8.
BMJ ; 356: j1054, 2017 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-28356302

RESUMO

Objectives To examine the impact of use of rapid diagnostic tests for malaria on prescribing of antimicrobials, specifically antibiotics, for acute febrile illness in Africa and Asia.Design Analysisof nine preselected linked and codesigned observational and randomised studies (eight cluster or individually randomised trials and one observational study).Setting Public and private healthcare settings, 2007-13, in Afghanistan, Cameroon, Ghana, Nigeria, Tanzania, and Uganda.Participants 522 480 children and adults with acute febrile illness.Interventions Rapid diagnostic tests for malaria.Main outcome measures Proportions of patients for whom an antibiotic was prescribed in trial groups who had undergone rapid diagnostic testing compared with controls and in patients with negative test results compared with patients with positive results. A secondary aim compared classes of antibiotics prescribed in different settings.Results Antibiotics were prescribed to 127 052/238 797 (53%) patients in control groups and 167 714/283 683 (59%) patients in intervention groups. Antibiotics were prescribed to 40% (35 505/89 719) of patients with a positive test result for malaria and to 69% (39 400/57 080) of those with a negative result. All but one study showed a trend toward more antibiotic prescribing in groups who underwent rapid diagnostic tests. Random effects meta-analysis of the trials showed that the overall risk of antibiotic prescription was 21% higher (95% confidence interval 7% to 36%) in intervention settings. In most intervention settings, patients with negative test results received more antibiotic prescriptions than patients with positive results for all the most commonly used classes: penicillins, trimethoprim-sulfamethoxazole (one exception), tetracyclines, and metronidazole.Conclusions Introduction of rapid diagnostic tests for malaria to reduce unnecessary use of antimalarials-a beneficial public health outcome-could drive up untargeted use of antibiotics. That 69% of patients were prescribed antibiotics when test results were negative probably represents overprescription.This included antibiotics from several classes, including those like metronidazole that are seldom appropriate for febrile illness, across varied clinical, health system, and epidemiological settings. It is often assumed that better disease specific diagnostics will reduce antimicrobial overuse, but they might simply shift it from one antimicrobial class to another. Current global implementation of malaria testing might increase untargeted antibiotic use and must be examined.


Assuntos
Antibacterianos/administração & dosagem , Malária/diagnóstico , Malária/tratamento farmacológico , Estudos Observacionais como Assunto , Padrões de Prática Médica/estatística & dados numéricos , Ensaios Clínicos Controlados Aleatórios como Assunto , Kit de Reagentes para Diagnóstico , África/epidemiologia , Assistência Ambulatorial , Antimaláricos/administração & dosagem , Antimaláricos/uso terapêutico , Ásia/epidemiologia , Testes Diagnósticos de Rotina , Febre/sangue , Febre/diagnóstico , Febre/tratamento farmacológico , Humanos , Malária/sangue , Avaliação de Programas e Projetos de Saúde
9.
PLoS One ; 11(1): e0146054, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26821179

RESUMO

BACKGROUND: Despite the fact that a large proportion of children with fever in Africa present at primary health care facilities, few studies have been designed to specifically study the causes of uncomplicated childhood febrile illness at this level of care, especially in areas like Zanzibar that has recently undergone a dramatic change from high to low malaria transmission. METHODS: We prospectively studied the aetiology of febrile illness in 677 children aged 2-59 months with acute uncomplicated fever managed by IMCI (Integrated Management of Childhood Illness) guidelines in Zanzibar, using point-of-care tests, urine culture, blood-PCR, chest X-ray (CXR) of IMCI-pneumonia classified patients, and multiple quantitative (q)PCR investigations of nasopharyngeal (NPH) (all patients) and rectal (GE) swabs (diarrhoea patients). For comparison, we also performed NPH and GE qPCR analyses in 167 healthy community controls. Final fever diagnoses were retrospectively established based on all clinical and laboratory data. Clinical outcome was assessed during a 14-day follow-up. The utility of IMCI for identifying infections presumed to require antibiotics was evaluated. FINDINGS: NPH-qPCR and GE-qPCR detected ≥1 pathogen in 657/672 (98%) and 153/164 (93%) of patients and 158/166 (95%) and 144/165 (87%) of controls, respectively. Overall, 57% (387/677) had IMCI-pneumonia, but only 12% (42/342) had CXR-confirmed pneumonia. Two patients were positive for Plasmodium falciparum. Respiratory syncytial virus (24.5%), influenza A/B (22.3%), rhinovirus (10.5%) and group-A streptococci (6.4%), CXR-confirmed pneumonia (6.2%), Shigella (4.3%) were the most common viral and bacterial fever diagnoses, respectively. Blood-PCR conducted in a sub-group of patients (n = 83) without defined fever diagnosis was negative for rickettsiae, chikungunya, dengue, Rift Valley fever and West Nile viruses. Antibiotics were prescribed to 500 (74%) patients, but only 152 (22%) had an infection retrospectively considered to require antibiotics. Clinical outcome was generally good. However, two children died. Only 68 (11%) patients remained febrile on day 3 and three of them had verified fever on day 14. An additional 29 (4.5%) children had fever relapse on day 14. Regression analysis determined C-reactive Protein (CRP) as the only independent variable significantly associated with CXR-confirmed pneumonia. CONCLUSIONS: This is the first study on uncomplicated febrile illness in African children that both applied a comprehensive laboratory panel and a healthy control group. A majority of patients had viral respiratory tract infection. Pathogens were frequently detected by qPCR also in asymptomatic children, demonstrating the importance of incorporating controls in fever aetiology studies. The precision of IMCI for identifying infections requiring antibiotics was low.


Assuntos
Antibacterianos/uso terapêutico , Febre/tratamento farmacológico , Influenza Humana/tratamento farmacológico , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Doença Aguda , Estudos de Casos e Controles , Pré-Escolar , Feminino , Febre/virologia , Humanos , Lactente , Masculino , Estudos Prospectivos , Infecções por Vírus Respiratório Sincicial/epidemiologia , Tanzânia/epidemiologia , Resultado do Tratamento
10.
Infect Genet Evol ; 33: 110-7, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25917493

RESUMO

BACKGROUND: Improved understanding of the asymptomatic malaria parasite reservoir is a prerequisite to pursue malaria elimination efforts. We therefore characterised temporal trends and transporter polymorphisms in asymptomatic Plasmodium infections during the transition from high to low transmission in Zanzibar. METHODS: Healthy individuals participating in cross-sectional surveys conducted 2005-2013 were screened for asymptomatic malaria by PCR. Complexity/diversity of infection and transporter polymorphisms were assessed in Plasmodium falciparum positive samples. Symptomatic samples were included for comparison of polymorphisms in 2013. RESULTS: PCR-determined parasite prevalence declined from 21.1% (CI95% 17.4-24.9) to 2.3% (CI95% 1.7-2.9) from 2005 to 2013. P. falciparum remained the predominant species; prevalence was highest in children and young adults aged 5-25 years. Parasite densities and complexity of infection, but not population genetic diversity of P. falciparum, decreased from 2005-2009. pfcrt 76T (99.2-64.7%, p < 0.001) and pfmdr1 86Y frequencies (89.4-66.7%, p = 0.03) decreased over time. Pfmdr1 (a.a.86,184,1246) YYY and YYD haplotypes were more frequent in asymptomatic than symptomatic infections in 2013 (p < 0.001). CONCLUSIONS: There is a declining, albeit persistent, reservoir of parasites present at low-densities in asymptomatic individuals in Zanzibar. This study revealed important characteristics of the remaining parasite population, including intriguing temporal trends in molecular markers associated with antimalarial resistance, which need to be further investigated.


Assuntos
Infecções Assintomáticas , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Proteínas de Membrana Transportadoras/genética , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Adolescente , Adulto , Criança , Pré-Escolar , Estudos Transversais , Feminino , Genótipo , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Carga Parasitária , Plasmodium falciparum/classificação , Polimorfismo de Nucleotídeo Único , Prevalência , Tanzânia/epidemiologia , Adulto Jovem
11.
PLoS One ; 10(3): e0120210, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25774805

RESUMO

A prerequisite for reliable detection of low-density Plasmodium infections in malaria pre-elimination settings is the availability of ultra-sensitive and high-throughput molecular tools. We developed a SYBR Green real-time PCR restriction fragment length polymorphism assay (cytb-qPCR) targeting the cytochrome b gene of the four major human Plasmodium species (P. falciparum, P. vivax, P. malariae, and P. ovale) for parasite detection and species determination with DNA extracted from dried blood spots collected on filter paper. The performance of cytb-qPCR was first compared against four reference PCR methods using serially diluted Plasmodium samples. The detection limit of the cytb-qPCR was 1 parasite/µl (p/µl) for P. falciparum and P. ovale, and 2 p/µl for P. vivax and P. malariae, while the reference PCRs had detection limits of 0.5-10 p/µl. The ability of the PCR methods to detect low-density Plasmodium infections was then assessed using 2977 filter paper samples collected during a cross-sectional survey in Zanzibar, a malaria pre-elimination setting in sub-Saharan Africa. Field samples were defined as 'final positive' if positive in at least two of the five PCR methods. Cytb-qPCR preformed equal to or better than the reference PCRs with a sensitivity of 100% (65/65; 95%CI 94.5-100%) and a specificity of 99.9% (2910/2912; 95%CI 99.7-100%) when compared against 'final positive' samples. The results indicate that the cytb-qPCR may represent an opportunity for improved molecular surveillance of low-density Plasmodium infections in malaria pre-elimination settings.


Assuntos
Citocromos b/genética , Genes de Protozoários , Malária/diagnóstico , Malária/parasitologia , Plasmodium/genética , Polimorfismo de Fragmento de Restrição , Reação em Cadeia da Polimerase em Tempo Real , Humanos , Plasmodium/classificação , RNA Ribossômico 18S , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase em Tempo Real/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
PLoS One ; 9(8): e103905, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25105591

RESUMO

BACKGROUND: Loop mediated isothermal amplification (LAMP) provides an opportunity for improved, field-friendly detection of malaria infections in endemic areas. However data on the diagnostic accuracy of LAMP for active case detection, particularly low-density parasitaemias, are lacking. We therefore evaluated the performance of a new LAMP kit compared with PCR using DNA from filter paper blood spots. METHODS AND FINDINGS: Samples from 865 fever patients and 465 asymptomatic individuals collected in Zanzibar were analysed for Pan (all species) and Pf (P. falciparum) DNA with the Loopamp MALARIA Pan/Pf kit. Samples were amplified at 65°C for 40 minutes in a real-time turbidimeter and results were compared with nested PCR. Samples with discordant results between LAMP and nested PCR were analysed with real-time PCR. The real-time PCR corrected nested PCR result was defined as gold standard. Among the 117 (13.5%) PCR detected P. falciparum infections from fever patients (mean parasite density 7491/µL, range 6-782,400) 115, 115 and 111 were positive by Pan-LAMP, Pf-LAMP and nested PCR, respectively. The sensitivities were 98.3% (95%CI 94-99.8) for both Pan and Pf-LAMP. Among the 54 (11.6%) PCR positive samples from asymptomatic individuals (mean parasite density 10/µL, range 0-4972) Pf-LAMP had a sensitivity of 92.7% (95%CI 80.1-98.5) for detection of the 41 P. falciparum infections. Pan-LAMP had sensitivities of 97% (95%CI 84.2-99.9) and 76.9% (95%CI 46.2-95) for detection of P. falciparum and P. malariae, respectively. The specificities for both Pan and Pf-LAMP were 100% (95%CI 99.1-100) in both study groups. CONCLUSION: Both components of the Loopamp MALARIA Pan/Pf detection kit revealed high diagnostic accuracy for parasite detection among fever patients and importantly also among asymptomatic individuals of low parasite densities from minute blood volumes preserved on filter paper. These data support LAMPs potential role for improved detection of low-density malaria infections in pre-elimination settings.


Assuntos
DNA de Protozoário/isolamento & purificação , Malária/sangue , Malária/diagnóstico , Técnicas de Amplificação de Ácido Nucleico/métodos , Primers do DNA/genética , DNA de Protozoário/sangue , Humanos , Limite de Detecção , Malária/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Tanzânia
13.
PLoS One ; 8(9): e72912, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24023791

RESUMO

BACKGROUND: We assessed if histidine-rich-protein-2 (HRP2) based rapid diagnostic test (RDT) remains an efficient tool for Plasmodium falciparum case detection among fever patients in Zanzibar and if primary health care workers continue to adhere to RDT results in the new epidemiological context of low malaria transmission. Further, we evaluated the performance of RDT within the newly adopted integrated management of childhood illness (IMCI) algorithm in Zanzibar. METHODS AND FINDINGS: We enrolled 3890 patients aged ≥ 2 months with uncomplicated febrile illness in this health facility based observational study conducted in 12 primary health care facilities in Zanzibar, between May-July 2010. One patient had an inconclusive RDT result. Overall 121/3889 (3.1%) patients were RDT positive. The highest RDT positivity rate, 32/528 (6.1%), was found in children aged 5-14 years. RDT sensitivity and specificity against PCR was 76.5% (95% CI 69.0-83.9%) and 99.9% (95% CI 99.7-100%), and against blood smear microscopy 78.6% (95% CI 70.8-85.1%) and 99.7% (95% CI 99.6-99.9%), respectively. All RDT positive, but only 3/3768 RDT negative patients received anti-malarial treatment. Adherence to RDT results was thus 3887/3889 (99.9%). RDT performed well in the IMCI algorithm with equally high adherence among children <5 years as compared with other age groups. CONCLUSIONS: The sensitivity of HRP-2 based RDT in the hands of health care workers compared with both PCR and microscopy for P. falciparum case detection was relatively low, whereas adherence to test results with anti-malarial treatment was excellent. Moreover, the results provide evidence that RDT can be reliably integrated in IMCI as a tool for improved childhood fever management. However, the relatively low RDT sensitivity highlights the need for improved quality control of RDT use in primary health care facilities, but also for more sensitive point-of-care malaria diagnostic tools in the new epidemiological context of low malaria transmission in Zanzibar. TRIAL REGISTRATION: ClinicalTrials.gov NCT01002066.


Assuntos
Testes Diagnósticos de Rotina/métodos , Malária/diagnóstico , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Malária/transmissão , Masculino , Plasmodium falciparum/patogenicidade , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Tanzânia
14.
Malar J ; 12: 106, 2013 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-23510231

RESUMO

BACKGROUND: The need for new malaria surveillance tools and strategies is critical, given improved global malaria control and regional elimination efforts. High quality Plasmodium falciparum DNA can reliably be extracted from malaria rapid diagnostic tests (RDTs). Together with highly sensitive molecular assays, wide scale collection of used RDTs may serve as a modern tool for improved malaria case detection and drug resistance surveillance. However, comparative studies of DNA extraction efficiency from RDTs and the field applicability are lacking. The aim of this study was to compare and evaluate different methods of DNA extraction from RDTs and to test the field applicability for the purpose of molecular epidemiological investigations. METHODS: DNA was extracted from two RDT devices (Paracheck-Pf® and SD Bioline Malaria Pf/Pan®), seeded in vitro with 10-fold dilutions of cultured 3D7 P. falciparum parasites diluted in malaria negative whole blood. The level of P. falciparum detection was determined for each extraction method and RDT device with multiple nested-PCR and real-time PCR assays. The field applicability was tested on 855 paired RDT (Paracheck-Pf) and filter paper (Whatman® 3MM) blood samples (734 RDT negative and 121 RDT positive samples) collected from febrile patients in Zanzibar 2010. RDT positive samples were genotyped at four key single nucleotide polymorphisms (SNPs) in pfmdr1 and pfcrt as well as for pfmdr1 copy number, all associated with anti-malarial drug resistance. RESULTS: The P. falciparum DNA detection limit varied with RDT device and extraction method. Chelex-100 extraction performed best for all extraction matrixes. There was no statistically significant difference in PCR detection rates in DNA extracted from RDTs and filter paper field samples. Similarly there were no significant differences in the PCR success rates and genotyping outcomes for the respective SNPs in the 121 RDT positive samples. CONCLUSIONS: The results support RDTs as a valuable source of parasite DNA and provide evidence for RDT-DNA extraction for improved malaria case detection, molecular drug resistance surveillance, and RDT quality control.


Assuntos
DNA de Protozoário/isolamento & purificação , Malária Falciparum/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Parasitologia/métodos , Plasmodium falciparum/isolamento & purificação , Manejo de Espécimes/métodos , DNA de Protozoário/genética , Dessecação/métodos , Humanos , Plasmodium falciparum/genética , Reação em Cadeia da Polimerase/métodos
15.
Malar J ; 12: 38, 2013 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-23360479

RESUMO

BACKGROUND: Formerly a high malaria transmission area, Zanzibar is now targeting malaria elimination. A major challenge is to avoid resurgence of malaria, the success of which includes maintaining high effective coverage of vector control interventions such as bed nets and indoor residual spraying (IRS). In this study, caretakers' continued use of preventive measures for their children is evaluated, following a sharp reduction in malaria transmission. METHODS: A cross-sectional community-based survey was conducted in June 2009 in North A and Micheweni districts in Zanzibar. Households were randomly selected using two-stage cluster sampling. Interviews were conducted with 560 caretakers of under-five-year old children, who were asked about perceptions on the malaria situation, vector control, household assets, and intention for continued use of vector control as malaria burden further decreases. RESULTS: Effective coverage of vector control interventions for under-five children remains high, although most caretakers (65%; 363/560) did not perceive malaria as presently being a major health issue. Seventy percent (447/643) of the under-five children slept under a long-lasting insecticidal net (LLIN) and 94% (607/643) were living in houses targeted with IRS. In total, 98% (628/643) of the children were covered by at least one of the vector control interventions. Seasonal bed-net use for children was reported by 25% (125/508) of caretakers of children who used bed nets. A high proportion of caretakers (95%; 500/524) stated that they intended to continue using preventive measures for their under-five children as malaria burden further reduces. Malaria risk perceptions and different perceptions of vector control were not found to be significantly associated with LLIN effective coverage. CONCLUSIONS: While the majority of caretakers felt that malaria had been reduced in Zanzibar, effective coverage of vector control interventions remained high. Caretakers appreciated the interventions and recognized the value of sustaining their use. Thus, sustaining high effective coverage of vector control interventions, which is crucial for reaching malaria elimination in Zanzibar, can be achieved by maintaining effective delivery of these interventions.


Assuntos
Malária/epidemiologia , Malária/prevenção & controle , Controle de Mosquitos/métodos , Adulto , Criança , Estudos Transversais , Características da Família , Conhecimentos, Atitudes e Prática em Saúde , Pesquisa sobre Serviços de Saúde , Humanos , Entrevistas como Assunto , Malária/transmissão , Tanzânia/epidemiologia
16.
Malar J ; 12: 37, 2013 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-23356837

RESUMO

BACKGROUND: In Zanzibar, malaria prevalence dropped substantially in the last decade and presently most febrile patients seen in primary health care facilities (PHCF) test negative for malaria. The availability of rapid diagnostic tests (RDTs) allows rural health workers to reliably rule out malaria in fever patients. However, additional diagnostic tools to identify alternative fever causes are scarce, often leaving RDT-negative patients without a clear diagnosis and management plan. This pilot study aimed to explore health workers' practices with febrile children and identify factors influencing their diagnostic and management decisions in non-malarial fever patients. METHODS: Semi-structured key informant interviews were conducted with 12 health workers in six PHCFs in North A district, Zanzibar, April to June 2011. Interviews were coded using Atlas.ti to identify emerging themes that play a role in the diagnosis and management of febrile children. RESULTS: The following themes were identified: 1) health workers use caregivers' history of illness and RDT results for initial diagnostic and management decisions, but suggest caregivers need more education to prevent late presentation and poor health outcomes; 2) there is uncertainty regarding viral versus bacterial illness and health workers feel additional point-of-care diagnostic tests would help with differential diagnoses; 3) stock-outs of medications and limited caregivers' resources are barriers to delivering good care; 4) training, short courses and participation in research as well as; 5) weather also influences diagnostic decision-making. CONCLUSIONS: This pilot study found that health workers in Zanzibar use caregiver history of fever and results of malaria RDTs to guide management of febrile children. However, since most febrile children test negative for malaria, health workers believe additional training and point-of-care tests would improve their ability to diagnose and manage non-malarial fevers. Educating caregivers on signs and symptoms of febrile illness, as well as the introduction of additional tests to differentiate between viral and bacterial illness, would be important steps to get children to PHCFs earlier and decrease unnecessary antibiotic prescribing without compromising patient safety. More research is needed to expand an understanding of what would improve fever management in other resource-limited settings with decreasing malaria.


Assuntos
Testes Diagnósticos de Rotina/métodos , Febre de Causa Desconhecida/diagnóstico , Febre de Causa Desconhecida/tratamento farmacológico , Atenção Primária à Saúde/métodos , Adulto , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Tanzânia
17.
Am J Trop Med Hyg ; 88(2): 289-91, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23249688

RESUMO

We screened for malaria in 594 blood samples from febrile patients who tested negative by a Plasmodium falciparum-specific histidine-rich protein-2-based rapid diagnostic test at 12 health facilities in Zanzibar districts North A and Micheweni, from May to August 2010. Screening was with microscopy, polymerase chain reaction (PCR) targeting the cytochrome b gene (cytbPCR) of the four major human malaria species, and quantitative PCR (qPCR). The prevalence of cytbPCR-detectable malaria infection was 2% (12 of 594), including 8 P. falciparum, 3 Plasmodium malariae, and 1 Plasmodium vivax infections. Microscopy identified 4 of 8 P. falciparum infections. Parasite density as estimated by microscopy or qPCR was > 4,000 parasites/µL in 5 of 8 cytbPCR-detectable P. falciparum infections. The infections that were missed by the rapid diagnostic test represent a particular challenge in malaria elimination settings and highlight the need for more sensitive point-of-care diagnostic tools to improve case detection of all human malaria species in febrile patients.


Assuntos
Malária/diagnóstico , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Adolescente , Adulto , Criança , Pré-Escolar , Primers do DNA , DNA de Protozoário/genética , Feminino , Humanos , Lactente , Malária/epidemiologia , Malária/parasitologia , Masculino , Microscopia , Plasmodium falciparum/genética , Plasmodium falciparum/patogenicidade , Plasmodium vivax/genética , Plasmodium vivax/patogenicidade , Prevalência , Inquéritos e Questionários , Tanzânia/epidemiologia , Viagem , Adulto Jovem
18.
Malar J ; 11: 321, 2012 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-22966778

RESUMO

BACKGROUND: Zanzibar has recently undergone a rapid decline in Plasmodium falciparum transmission following combined malaria control interventions with artemisinin-based combination therapy (ACT) and integrated vector control. Artesunate-amodiaquine (ASAQ) was implemented as first-line treatment for uncomplicated P. falciparum malaria in Zanzibar in 2003. Resistance to amodiaquine has been associated with the single nucleotide polymorphism (SNP) alleles pfcrt 76T, pfmdr1 86Y, 184Y and 1246Y. An accumulation of these SNP alleles in the parasite population over time might threaten ASAQ efficacy.The aim of this study was to assess whether prolonged use of ASAQ as first-line anti-malarial treatment selects for P. falciparum SNPs associated with resistance to the ACT partner drug amodiaquine. METHODS: The individual as well as the combined SNP allele prevalence were compared in pre-treatment blood samples from patients with uncomplicated P. falciparum malaria enrolled in clinical trials conducted just prior to the introduction of ASAQ in 2002-2003 (n = 208) and seven years after wide scale use of ASAQ in 2010 (n = 122). RESULTS: There was a statistically significant decrease of pfcrt 76T (96-63%), pfmdr1 86Y (75-52%), 184Y (83-72%), 1246Y (28-16%) and the most common haplotypes pfcrt/pfmdr1 TYYD (46-26%) and TYYY (17-8%), while an increase of pfcrt/pfmdr1 KNFD (0.4-14%) and KNYD (1-12%). CONCLUSIONS: This is the first observation of a decreased prevalence of pfcrt 76T, pfmdr1 86Y, 184Y and 1246Y in an African setting after several years of extensive ASAQ use as first-line treatment for uncomplicated malaria. This may support sustained efficacy of ASAQ on Zanzibar, although it was unexpected considering that all these SNPs have previously been associated with amodiaquine resistance. The underlying factors of these results are unclear. Genetic dilution by imported P. falciparum parasites from mainland Tanzania, a de-selection by artesunate per se and/or an associated fitness cost might represent contributing factors. More detailed studies on temporal trends of molecular markers associated with amodiaquine resistance are required to improve the understanding of this observation.


Assuntos
Amodiaquina/farmacologia , Antimaláricos/farmacologia , Resistência a Medicamentos , Malária Falciparum/parasitologia , Plasmodium falciparum/efeitos dos fármacos , Amodiaquina/uso terapêutico , Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Ensaios Clínicos como Assunto , Frequência do Gene , Humanos , Lactonas/uso terapêutico , Malária Falciparum/tratamento farmacológico , Proteínas de Membrana Transportadoras/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Mutação de Sentido Incorreto , Plasmodium falciparum/isolamento & purificação , Mutação Puntual , Polimorfismo de Nucleotídeo Único , Prevalência , Proteínas de Protozoários/genética , Tanzânia
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