RESUMO
BACKGROUND: Malaria diagnostics by rapid diagnostic test (RDT) relies primarily on the qualitative detection of Plasmodium falciparum histidine-rich protein 2 (PfHRP2) and Plasmodium spp lactate dehydrogenase (pLDH). As novel RDTs with increased sensitivity are being developed and implemented as point of care diagnostics, highly sensitive laboratory-based assays are needed for evaluating RDT performance. Here, a quantitative suspension array technology (qSAT) was developed, validated and applied for the simultaneous detection of PfHRP2 and pLDH in a variety of biological samples (whole blood, plasma and dried blood spots) from individuals living in different endemic countries. RESULTS: The qSAT was specific for the target antigens, with analytical ranges of 6.8 to 762.8 pg/ml for PfHRP2 and 78.1 to 17076.6 pg/ml for P. falciparum LDH (Pf-LDH). The assay detected Plasmodium vivax LDH (Pv-LDH) at a lower sensitivity than Pf-LDH (analytical range of 1093.20 to 187288.5 pg/ml). Both PfHRP2 and pLDH levels determined using the qSAT showed to positively correlate with parasite densities determined by quantitative PCR (Spearman r = 0.59 and 0.75, respectively) as well as microscopy (Spearman r = 0.40 and 0.75, respectively), suggesting the assay to be a good predictor of parasite density. CONCLUSION: This immunoassay can be used as a reference test for the detection and quantification of PfHRP2 and pLDH, and could serve for external validation of RDT performance, to determine antigen persistence after parasite clearance, as well as a complementary tool to assess malaria burden in endemic settings.
Assuntos
Antígenos de Protozoários/sangue , L-Lactato Desidrogenase/sangue , Malária Falciparum/diagnóstico , Malária Vivax/diagnóstico , Proteínas de Protozoários/sangue , Adolescente , Adulto , África , Animais , Biotina , Calibragem , Criança , Estudos Transversais , Feminino , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Malária Falciparum/sangue , Malária Vivax/sangue , Camundongos , Microesferas , Parasitemia/sangue , Parasitemia/diagnóstico , Gravidez , Reação em Cadeia da Polimerase em Tempo Real , América do Sul , Espanha , Adulto JovemAssuntos
Malária Vivax/diagnóstico , Auditoria Médica , Militares , Campanha Afegã de 2001- , Afeganistão , Animais , Antimaláricos/uso terapêutico , Celulite (Flegmão)/complicações , Celulite (Flegmão)/diagnóstico , Cloroquina/uso terapêutico , Diagnóstico Diferencial , Humanos , Malária Vivax/complicações , Malária Vivax/tratamento farmacológico , Masculino , Entorpecentes/efeitos adversos , Ópio/efeitos adversos , Sepse/diagnóstico , Sepse/tratamento farmacológico , Sepse/etiologia , Síndrome de Abstinência a Substâncias/diagnóstico , Inquéritos e Questionários , Reino Unido , Adulto JovemRESUMO
BACKGROUND: Early diagnosis and treatment with artesunate-mefloquine combination therapy (MAS) have reduced the transmission of falciparum malaria dramatically and halted the progression of mefloquine resistance in camps for displaced persons along the Thai-Burmese border, an area of low and seasonal transmission of multidrug-resistant Plasmodium falciparum. We extended the same combination drug strategy to all other communities (estimated population 450,000) living in five border districts of Tak province in northwestern Thailand. METHODS AND FINDINGS: Existing health structures were reinforced. Village volunteers were trained to use rapid diagnostic tests and to treat positive cases with MAS. Cases of malaria, hospitalizations, and malaria-related deaths were recorded in the 6 y before, during, and after the Tak Malaria Initiative (TMI) intervention. Cross-sectional surveys were conducted before and during the TMI period. P. falciparum malaria cases fell by 34% (95% confidence interval [CI], 33.5-34.4) and hospitalisations for falciparum malaria fell by 39% (95% CI, 37.0-39.9) during the TMI period, while hospitalisations for P. vivax malaria remained constant. There were 32 deaths attributed to malaria during, and 22 after the TMI, a 51.5% (95% CI, 39.0-63.9) reduction compared to the average of the previous 3 y. Cross-sectional surveys indicated that P. vivax had become the predominant species in Thai villages, but not in populations living on the Myanmar side of the border. In the displaced persons population, where the original deployment took place 7 y before the TMI, the transmission of P. falciparum continued to be suppressed, the incidence of falciparum malaria remained low, and the in vivo efficacy of the 3-d MAS remained high. CONCLUSIONS: In the remote malarious north western border area of Thailand, the early detection of malaria by trained village volunteers, using rapid diagnostic tests and treatment with mefloquine-artesunate was feasible and reduced the morbidity and mortality of multidrug-resistant P. falciparum.
Assuntos
Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Malária Falciparum/diagnóstico , Malária Falciparum/tratamento farmacológico , Mefloquina/uso terapêutico , Complicações Parasitárias na Gravidez/tratamento farmacológico , Sesquiterpenos/uso terapêutico , Adulto , Idoso , Artesunato , Estudos Transversais , Quimioterapia Combinada , Diagnóstico Precoce , Feminino , Mortalidade Hospitalar , Hospitalização , Humanos , Incidência , Malária Falciparum/epidemiologia , Malária Falciparum/prevenção & controle , Malária Vivax/diagnóstico , Malária Vivax/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Programas Nacionais de Saúde , Testes de Sensibilidade Parasitária , Gravidez , Complicações Parasitárias na Gravidez/diagnóstico , Prevalência , Refugiados , Tailândia/epidemiologia , Clima TropicalRESUMO
BACKGROUND: Although suppositories of artemisinin derivatives may be a valuable option for treatment of malaria in children when circumstances prevent oral and parenteral therapy, few confirmatory data have been published. METHODS: We assessed the safety and efficacy of rectal artesunate in 47 children ages 5 to 10 years with uncomplicated malaria acquired in a hyperendemic area of Papua New Guinea. Thirty were symptomatic and had Plasmodium falciparum parasitemia >2000/microl (Group 1), 12 had and either a parasitemia <2000/microl or minimal/no symptoms (Group 2) and 5 had Plasmodium vivax (Group 3). Each child received rectal artesunate 10 to 15 mg/kg at 0 and 12 h. After monitoring for 24 h, chloroquine plus sulfadoxine/pyrimethamine was given, and the patient discharged. RESULTS: Artesunate suppositories were well-tolerated. After 24 h only one child (from Group 1) had persistent parasitemia, and only one (from Group 3) had not defervesced. These two children received intramuscular quinine and recovered uneventfully. Three Group 2 children redeveloped fever and tachycardia at 24 h, but each responded to simple supportive measures and remained aparasitemic. CONCLUSIONS: Intrarectal artesunate is safe, effective initial treatment for uncomplicated malaria in children. A transient fever spike can sometimes occur after parasite clearance. We recommend that children with uncomplicated malaria receive two doses of > or =10 mg/kg rectal artesunate within the first 24 h.
Assuntos
Antimaláricos/administração & dosagem , Artemisininas/administração & dosagem , Doenças Endêmicas/estatística & dados numéricos , Malária Falciparum/tratamento farmacológico , Malária Vivax/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Plasmodium vivax/efeitos dos fármacos , Sesquiterpenos/administração & dosagem , Animais , Artesunato , Criança , Pré-Escolar , Estudos de Coortes , Países em Desenvolvimento , Relação Dose-Resposta a Droga , Esquema de Medicação , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Malária Falciparum/diagnóstico , Malária Falciparum/epidemiologia , Malária Vivax/diagnóstico , Malária Vivax/epidemiologia , Masculino , Monitorização Fisiológica , Papua Nova Guiné/epidemiologia , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Estudos Prospectivos , Sulfadoxina/administração & dosagem , Supositórios , Resultado do TratamentoRESUMO
Logistic, economic and technical factors limit rapid access to microscopic confirmation of symptomatic diagnosis of malaria in many rural areas in endemic countries such as Myanmar. A study was conducted to evaluate a rapid on-site immunochromatographic test (ICT Malaria Pf/Pv) for detection of Plasmodium falciparum and P. vivax in two villages in the Taikkyi region of Myanmar. The ICT Malaria tests were performed by a volunteer health worker (VHW) in Yae-Aye-San village and by a professionally trained midwife (MW) in Kankone village. A total of 1000 symptomatic patients participated in the study by providing blood samples for an ICT test and for microscopy. The ICT performance indices, relative to microscopy, were better for the trained MW compared with the less experienced VHW. For P. falciparum and/or P. vivax infections, the sensitivities were 82.7% for the VHW compared with 93.7% for the MW. For P. falciparum infections, the sensitivities were 82.2% for the VHW and 91.3% for the MW, while the corresponding values for P. vivax infections were 66.7 and 79%, respectively. Although the test kit appeared to perform better in more experienced hands, this study questions whether this difference is related to the use of the ICT Malaria Pf/Pv test kit, or related to other factors such as differences in the quality of blood slides prepared by the VHW and MW for microscopic examination. Overall, the results suggest that a rapid diagnostic assay such as the ICT Malaria Pf/Pv test kit can be used in rural settings by relatively inexperienced persons, such as VHWs, with a reasonable degree of sensitivity, thus providing on-site confirmation of symptomatic diagnosis of malaria.
Assuntos
Malária/diagnóstico , Kit de Reagentes para Diagnóstico , Animais , Agentes Comunitários de Saúde , Humanos , Malária Falciparum/diagnóstico , Malária Vivax/diagnóstico , Tocologia , Mianmar , Plasmodium falciparum/imunologia , Plasmodium vivax/imunologia , População Rural , Sensibilidade e EspecificidadeRESUMO
In order to assess the current pattern of malaria presenting to the Aberdeen Infection Unit a retrospective casenote review was undertaken of 110 patients admitted with that diagnosis between 1st January 1992 and 31st August 1999. Oil-related work was the reason for travel in 48 (43.6%) of the UK residents, holiday in 35 (31.8%), backpacking in 8 (7.3%) and other work in 5 (4.5%). Sixty-five patients (59.1%) had PL falciparum malaria (pure or mixed), 25 (22.7%) had PL vivax, 6 (5.4%) PL ovale and 3 (2.7%) PL malariae infection. No prophylaxis had been taken by 66% of the 47 UK-based oil workers and by 36% of the other 48 UK residents who had returned from Africa. There is a need for better education of oil workers and holidaymakers travelling to areas endemic for malaria. We are now setting up a travel advisory service in our Unit to address the problem.