Malaria

Malaria is a subtropical and tropical protozoan infection that accounts for nearly half a million deaths each year. Most deaths occur in sub-Saharan Africa and are caused by Plasmodium falciparum. The least studied of the five Plasmodia species that cause malaria, P. knowlesi, along with P. vivax cause life-threatening disease, mostly in Southeast Asia. Children, pregnant women, and non-immune travellers to endemic countries are most vulnerable to severe malaria. Cerebral malaria and anaemia are complications that results in neurological deficit and death if treatment is delayed or inappropriately administered. Rapid diagnostic tests have emerged as accurate and reliable means to diagnosing malaria at point-of-care.

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Improving Accuracy of Malaria Diagnosis in Underserved Rural and Remote Endemic Areas of Sub-Saharan Africa: A Call to Develop Multiplexing Rapid Diagnostic Tests

Scientifica ◽

10.1155/2020/3901409 ◽

2020 ◽

Vol 2020 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Rasheed O. Makanjuola ◽

Andrew W. Taylor-Robinson

Keyword(s):

Low Income ◽

Diagnostic Tests ◽

Medical Condition ◽

Hot Spot ◽

Rapid Diagnostic Tests ◽

Sub Saharan Africa ◽

Low Income Countries ◽

Patient Treatment ◽

Sub Saharan ◽

Effective Diagnosis

Clinical infection with malaria, caused by parasites of the genus Plasmodium, is considered a serious medical condition with the potential to become a life-threatening emergency. This is especially relevant to low-income countries in tropical and subtropical regions of the world where high rates of malaria-related morbidity and mortality are recorded. As a means to combat this major global public health threat, rapid and effective diagnosis remains the frontline action to initiate a timely and appropriate medical intervention. From all the approaches to parasite detection, rapid diagnostic tests, so-called RDTs, are the easiest to use and most cost-effective. However, some of the limitations inherent in this methodology could hinder effective patient treatment. A primary drawback is that the vast majority of commercially available RDTs detect only one of the five species of human malaria, P. falciparum. While this is the main cause of infection in many areas, it excludes the possibility of infection with another parasite (P. vivax, P. ovale, P. malariae, and P. knowlesi) or of mixed infections containing different species. Hence, a diagnosis of non-P. falciparum malaria is missed. In turn, in resource-constrained settings where optimal microscopy is not available, a misdiagnosis of bacterial infection based on signs and symptoms alone often results in an inappropriate prescription of antibiotics. Here, we discuss how effective diagnosis of malaria and indiscriminate use of antibiotics in sub-Saharan Africa, a hot spot for P. falciparum transmission, may both be addressed by the development of innovative multiplexing RDTs that detect two or more species of Plasmodium.

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PO 8271 PFHRP2 GENE DELETIONS IN PLASMODIUM FALCIPARUM AND SCHISTOSOMA MANSONI CO-INFECTIONS: AN EMERGING CHALLENGE FOR MALARIA RAPID DIAGNOSTIC TESTS

BMJ Global Health ◽

10.1136/bmjgh-2019-edc.64 ◽

2019 ◽

Vol 4 (Suppl 3) ◽

pp. A25.2-A25

Author(s):

Hilda Echelibe ◽

Masumbe Netongo Palmer ◽

Nji Akindeh ◽

Wilfred Mbacham

Keyword(s):

Plasmodium Falciparum ◽

Schistosoma Mansoni ◽

Diagnostic Tests ◽

False Negative ◽

Rapid Diagnostic Tests ◽

Sub Saharan Africa ◽

P Value ◽

Gene Deletions ◽

Malaria Rdts ◽

Malaria Rapid Diagnostic Tests

BackgroundMalaria and schistosomiasis are infections that have a great impact in sub-Saharan Africa based on their high morbidity and mortality rates. We suggest the possibility that the microenvironment created from interactions between the parasites involved generates a pressure on the malaria parasite which could in turn favour the parasite’s adaptation or escape through Pfhrp2 gene deletions. Thus, this study aimed at determining the association between the co-infection with both parasites and false-negative PfHRP2-based malaria rapid diagnostic tests which occur because of these deletions.MethodsThis pilot study was conducted in a total of 149 children aged 7–17 years living in Yorro, located in the Mbam-Inoubou division of the Center region of Cameroon. We collected fresh stool samples from each participant to identify Schistosoma mansoni (Sm) eggs by Kato Katz method and blood samples to identify the ring stages of Plasmodium falciparum (Pf) by thick smear. Malaria rapid diagnostic test and Pfhrp2 gene polymerase chain reaction were performed. The association between the co-infection with Sm/Pf and the false-negative malaria RDTs was determined by the Fisher’s exact test. A p value<0.05 was considered statistically significant.ResultsOur results showed that samples were singly infected with Sm, Pf, co-infected (Sm/Pf) and negative for both infections at frequencies of 12%, 43%, 30.2% and 14.8% respectively. False-negative PfHRP2-based RDTs were observed in 4.7% of the participants. A higher frequency (5/7) of the cases with false-negative malaria RDTs were co-infected with Sm/Pf. A p value of 0.027 showed statistical significance in the association of Sm/Pf co-infection and false-negative PfHRP2-based RDTs.ConclusionA significant association of Plasmodium falciparum and Schistosoma mansoni co-infection with false-negative PfHRP2-based RDTs supports the case for a plausible implication of Pfhrp2 gene deletions, with consequences for malaria rapid diagnostic testing.

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Asexual and sexual stages of Plasmodium falciparum in Nigerian pregnant women attending antenatal booking clinic

Obstetric Medicine ◽

10.1258/om.2010.090060 ◽

2010 ◽

Vol 3 (3) ◽

pp. 106-109 ◽

Cited By ~ 2

Author(s):

S T Balogun ◽

F A Fehintola ◽

O A Adeyanju ◽

A A Adedeji

Keyword(s):

Plasmodium Falciparum ◽

Preterm Birth ◽

Infant Mortality ◽

Pregnant Women ◽

Blood Meal ◽

Sub Saharan Africa ◽

Female Mosquito ◽

Susceptibility To Infection ◽

Sexual Stages ◽

Sub Saharan

Susceptibility to infection by Plasmodium falciparum is increased in pregnant women. In sub-Saharan Africa, the consequences of maternal malaria include preterm birth, fetal growth restriction and increased infant mortality. Malaria transmission requires the circulation of viable gametocytes that can be ingested by the female mosquito taking a blood meal. This study was conducted to evaluate the presence of asexual and sexual stages of P. falciparum in pregnant women attending antenatal booking clinics in south-western Nigeria, an area hyper-endemic for malaria. Gametocyte carriage was about 13%, similar to that documented for children symptomatic for malaria in our area of study.

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Asymptomatic Malaria Correlates with Anaemia in Pregnant Women at Ouagadougou, Burkina Faso

Journal of Biomedicine and Biotechnology ◽

10.1155/2012/198317 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 18

Author(s):

Zoenabo Douamba ◽

Cyrille Bisseye ◽

Florencia W. Djigma ◽

Tegwinde R. Compaoré ◽

Valérie Jean Telesphore Bazie ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Pregnant Women ◽

Rapid Detection ◽

Intermittent Preventive Treatment ◽

Preventive Treatment ◽

Asymptomatic Infection ◽

Sub Saharan Africa ◽

Asymptomatic Malaria ◽

Low Levels ◽

Sub Saharan

Sub-Saharan Africa records each year about thirty-two million pregnant women living in areas of high transmission ofPlasmodium falciparumcausing malaria. The aim of this study was to carve out the prevalence of asymptomatic malaria among pregnant women and to emphasize its influence on haematological markers. The prevalence ofPlasmodium falciparumasymptomatic infection among pregnant women was 30% and 24% with rapid detection test (RDT) and microscopy, respectively. The prevalence ofP. falciparumasymptomatic malaria was reduced among pregnant women using sulfadoxine-pyrimethamine's intermittent preventive treatment and 61% of them were anaemic. Anaemia was significantly more common in women infected withP. falciparumcompared with the uninfected pregnant women. Most of the women had normal levels of homocysteine and low levels of folate, respectively. Therefore, the systematic diagnosis of malaria should be introduced to pregnant women as a part of the antenatal care.

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Rapid diagnostic tests for bacterial meningitis applicable in sub-Saharan Africa

Cochrane Database of Systematic Reviews ◽

10.1002/14651858.cd011634.pub2 ◽

2019 ◽

Author(s):

Thomas D Waite ◽

Lilanganee Telisinghe ◽

Maya Gobin ◽

Olivier Ronveaux ◽

Ana-Katya Fernandez ◽

...

Keyword(s):

Bacterial Meningitis ◽

Diagnostic Tests ◽

Rapid Diagnostic Tests ◽

Sub Saharan Africa ◽

Sub Saharan

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Parasitological Clearance Rates and Drug Concentrations of a Fixed Dose Combination of Azithromycin-Chloroquine in Asymptomatic Pregnant Women with Plasmodium Falciparum Parasitemia: An Open-Label, Non-Comparative Study in Sub-Saharan Africa

PLoS ONE ◽

10.1371/journal.pone.0165692 ◽

2016 ◽

Vol 11 (11) ◽

pp. e0165692 ◽

Cited By ~ 5

Author(s):

Kamija Phiri ◽

Joshua Kimani ◽

George A. Mtove ◽

Qinying Zhao ◽

Ricardo Rojo ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Comparative Study ◽

Pregnant Women ◽

Sub Saharan Africa ◽

Fixed Dose ◽

Clearance Rates ◽

Open Label ◽

Drug Concentrations ◽

Dose Combination ◽

Sub Saharan

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Diagnosis of Cryptococcosis and Prevention of Cryptococcal Meningitis Using a Novel Point-of-Care Lateral Flow Assay

Case Reports in Medicine ◽

10.1155/2013/640216 ◽

2013 ◽

Vol 2013 ◽

pp. 1-4 ◽

Cited By ~ 8

Author(s):

Ashar Dhana

Keyword(s):

Cryptococcal Meningitis ◽

Point Of Care ◽

World Health Organisation ◽

Lateral Flow ◽

Sub Saharan Africa ◽

World Health ◽

First Case ◽

Lateral Flow Dipstick ◽

Life Threatening ◽

Sub Saharan

Despite access to antiretroviral therapy, mortality from cryptococcal meningitis (CM) is high among persons with advanced HIV infection in sub-Saharan Africa. Cryptococcal antigen (CrAg) is present several weeks to months before the onset of symptoms of meningitis and can be screened to prevent life threatening meningitis. Recently, the World Health Organisation recommended that a new rapid CrAg lateral flow ‘‘dipstick’’ assay (LFA) is to be used to screen HIV-infected persons with CD4 counts of less than 100 cells/µL. In this paper, we describe two cases of cryptococcosis with differing outcomes. In the first case, the new CrAg LFA was used as part of a screen and preemptive treatment strategy to prevent CM. In the second case, our patient had no access to the CrAg LFA and subsequently developed life threatening meningitis. To the best of our knowledge, this is the first case report of cryptococcosis diagnosed using this novel assay.

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Evaluating Field Performance of Highly Sensitive Malaria RDT: Detection of Infection Among Febrile Patients, Asymptomatic Pregnant Women and Household Contacts in Mpigi, Uganda

10.21203/rs.3.rs-917448/v1 ◽

2021 ◽

Author(s):

Daniel Kyabayinze ◽

Dan Kajungu ◽

Proscovia M. Nambuya ◽

Christopher Okiira ◽

Bbaale Ndawula ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Pregnant Women ◽

Diagnostic Tests ◽

Health Workers ◽

Training Session ◽

Rapid Diagnostic Tests ◽

Community Settings ◽

Targeted Interventions ◽

Training Requirements ◽

Highly Sensitive

Abstract BackgroundWorld Health Organisation recommends that malaria case management be based on parasite-based diagnosis in all cases, but currently available tools for clinical use have limitations, including the inability to detect low-level infections. Currently, next-generation highly sensitive rapid diagnostic tests (hsRDT) for Plasmodium falciparum (Pf) are commercially available, but require field-based validation. This study evaluated the performance of the highly sensitive NxTek™ Eliminate Malaria Pf (NxTek) diagnostic test in health facilities and community settings in Mpigi district, Uganda in comparison to the conventional rapid diagnostic tests (cRDTs).MethodsBetween April and December 2019, symptomatic and asymptomatic participants were randomly enrolled from the Outpatient Department (OPD), Antenatal Care (ANC), and community settings. The participants were tested with both cRDTs and an hsRDT to detect Plasmodium falciparum HRP2 antigen and quality assured results with PCR as a reference. Geo-coded real time data were transmitted by health facility and community-based providers using a smartphone with custom designed software.ResultsAt the OPD, the parasite positivity rate was 13.3% for HS-RDT, compared to 6.4% with cRDT. The HS-RDT detected twice the number of positives compared to cRDT. At ANC, 11% (384/3,490) of the pregnant women were malaria parasite positive. HS-RDT detected more positive cases (10.4%) than cRDT (7.0%). At the community setting, 79.7% (2,397/3,009) of the under-five age group were positive for malaria parasites. Index clients in households resulted in a detection of 21.1% (1,877) asymptomatic positive especially among school going children. Health workers were able to learn how to effectively perform the HS-RDT, from a one-day training session. The additional support supervision was provided for VHTs to enable all to transmit results through the android phones. ConclusionUse of HS-RDTs increased case findings of low parasite density infections compared to cRDTs in study populations and provides the opportunity to eliminate malaria reservoirs through treatments. There were minimal additional training requirements when the HS-RDT kits were introduced. The observed increased positivity rates among school-age children call for integrating targeted interventions into school health programs.

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