RESUMO
Malaria is among the major threats to global health with the main burden of disease being in rural areas of developing countries where accurate diagnosis based on non-invasive samples is in high demand. We here present a novel molecular assay for detection of malaria parasites based on technology that may be adapted for low-resource settings. Moreover, we demonstrate the exploitation of this assay for detection of malaria in saliva. The setup relies on pump-free microfluidics enabled extraction combined with a DNA sensor substrate that is converted to a single-stranded DNA circle specifically by topoisomerase I expressed by the malaria causing Plasmodium parasite. Subsequent rolling circle amplification of the generated DNA circle in the presence of biotin conjugated deoxynucleotides resulted in long tandem repeat products that was visualized colorimetrically upon binding of horse radish peroxidase (HRP) and addition of 3,3',5,5'-Tetramethylbenzidine that was converted to a blue colored product by HRP. The assay was directly quantitative, specific for Plasmodium parasites, and allowed detection of Plasmodium infection in a single drop of saliva from 35 out of 35 infected individuals tested. The results could be determined directly by the naked eye and documented by quantifying the color intensity using a standard paper scanner.
Assuntos
DNA Topoisomerases Tipo I/metabolismo , DNA/química , Malária Falciparum , Plasmodium falciparum/enzimologia , Proteínas de Protozoários/metabolismo , Saliva/metabolismo , Biomarcadores/metabolismo , Colorimetria/métodos , Humanos , Malária Falciparum/diagnóstico , Malária Falciparum/enzimologiaRESUMO
An estimated 40 million women of childbearing age suffer from schistosomiasis. Animal models indicate a deleterious effect of maternal schistosomiasis on pregnancy outcomes. To date there is a lack of epidemiological evidence evaluating schistosomiasis-related morbidity in pregnancy. This study was designed to describe the impact of urogenital schistosomiasis on pregnancy outcomes in a highly endemic region of central Africa. Pregnant women attending antenatal clinics in Fougamou and Lambaréné, Gabon, were consecutively screened for the presence of Schistosoma haematobium eggs in diurnal urine samples. Maternal and newborn characteristics assessed at delivery were compared between infected and uninfected mothers. The impact of maternal schistosomiasis on low birth weight and preterm delivery was assessed using logistic regression analysis. Urogenital schistosomiasis was diagnosed in 103 (9%) of 1115 pregnant women. Maternal age was inversely associated with the prevalence of urogenital schistosomiasis, with a higher burden amongst nulliparous women. Low birth weight was more common amongst infants of S. haematobium-infected mothers. This association was unaffected by controlling for demographic characteristics, gestational age and Plasmodium infection status (adjusted Odds Ratio 1.93; 95% confidence interval: 1.08-3.42). Other risk factors associated with low birth weight delivery were underweight mothers (adjusted Odds Ratio 2.34; 95% confidence interval: 1.12-4.92), peripheral or placental Plasmodium falciparum infection (adjusted Odds Ratio 2.04; 95% confidence interval: 1.18-3.53) and preterm birth (adjusted Odds Ratio 3.12; 95% confidence interval: 1.97-4.96). Preterm delivery was not associated with S. haematobium infection (adjusted Odds Ratio 1.07 95% confidence interval: 0.57-1.98). In conclusion, this study indicates that pregnant women with urogenital schistosomiasis are at an increased risk for low birth weight deliveries. Further studies evaluating targeted treatment and prevention programmes for urogenital schistosomiasis in pregnant women and their impact on delivery outcomes are warranted.
Assuntos
Recém-Nascido de Baixo Peso , Complicações Infecciosas na Gravidez/fisiopatologia , Complicações Infecciosas na Gravidez/parasitologia , Esquistossomose Urinária/fisiopatologia , Adolescente , Adulto , Animais , Doenças Endêmicas , Feminino , Gabão/epidemiologia , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Malária/complicações , Malária Falciparum/complicações , Masculino , Trabalho de Parto Prematuro/epidemiologia , Trabalho de Parto Prematuro/parasitologia , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/urina , Resultado da Gravidez/epidemiologia , Prevalência , Estudos Prospectivos , Fatores de Risco , Schistosoma haematobium/isolamento & purificação , Esquistossomose Urinária/diagnóstico , Esquistossomose Urinária/epidemiologia , Esquistossomose Urinária/urina , Adulto JovemRESUMO
Premastication-defined as pre-chewing of food for infants by their caregiver-is a common feeding practice in various societies. To date the impact of premastication on children's health including the potential for transmission of infectious diseases is not well understood. Since there are no epidemiologic data on premastication from resource poor regions in Central Africa, we investigated the epidemiology and demographic variables associated with premastication in Central Africa. Between 2011 and 2012, mothers were interviewed about child feeding behaviors in three rural communities in Gabon. A quarter (n = 20, 24%) of 82 participants stated to perform premastication regularly. Despite the small sample size, our study provides first baseline data for the epidemiology of premastication in Central Africa, indicating that this feeding practice is common in rural communities.
Assuntos
Comportamento Alimentar , Mastigação , Mães , População Rural , Adulto , Cuidadores , Criança , Proteção da Criança , Pré-Escolar , Estudos Transversais , Características da Família , Feminino , Gabão , Humanos , Lactente , Entrevistas como Assunto , Masculino , Idade Materna , Fatores Socioeconômicos , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Urogenital schistosomiasis is a major public health problem in sub-Saharan Africa, and routine programs for screening and treatment of pregnant women are not established. Mefloquine-currently evaluated as a potential alternative to sulfadoxine-pyrimethamine as intermittent preventive treatment against malaria in pregnancy (IPTp)-is known to exhibit activity against Schistosoma haematobium. In this study we evaluated the efficacy of mefloquine IPTp against S. haematobium infection in pregnant women. METHODS: Pregnant women with S. haematobium infection presenting at 2 antenatal health care centers in rural Gabon were invited to participate in this nested randomized controlled, assessor-blinded clinical trial comparing sulfadoxine-pyrimethamine with mefloquine IPTp. Study drugs were administered twice during pregnancy with a 1- month interval after completion of the first trimester. RESULTS: Sixty-five pregnant women were included in this study. Schistosoma haematobium egg excretion rates showed a median reduction of 98% (interquartile range [IQR], 70%-100%) in the mefloquine group compared to an increase of 20% (IQR, -186% to 75%) in the comparator group. More than 80% of patients showed at least 50% reduction of egg excretion and overall cure rate was 47% (IQR, 36%-70%) 6 weeks after the second administration of mefloquine IPTp. CONCLUSION: When used as IPTp for the prevention of malaria, mefloquine shows promising activity against concomitant S. haematobium infection leading to an important reduction of egg excretion in pregnant women. Provided that further studies confirm these findings, the use of mefloquine may transform future IPTp programs into a 2-pronged intervention addressing 2 of the most virulent parasitic infections in pregnant women in sub-Saharan Africa. CLINICAL TRIALS REGISTRATION: NCT01132248; ATMR2010020001429343.