Detection Of Malaria Parasites Research Articles

Efficacy of Plasmodium falciparum histidine-rich protein 2 ( Pfhrp 2) rapid diagnostic test (RDT) and microscopy in the detection of falciparum malaria among symptomatic patients in Akure, Nigeria.

Accurate diagnosis and prompt treatment are highly essential in the management of malaria, which is one of the deadliest infectious diseases worldwide, particularly in tropical and sub-tropical regions including Nigeria. This study was designed to evaluate the efficacy of malaria histidine-rich protein 2-based rapid diagnostic test (RDT) and microscopy in the diagnosis of falciparum malaria in Nigeria. This was a cross-sectional and hospital-based study. The standard method of microscopy was used as the gold standard. Giemsa stained thick and thin smears were prepared to count and detect malaria parasite species. Also, a malaria histidine-rich protein 2-based RDT was used to detect malaria parasites and diagnostic efficacy were determined through the measure of sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV), diagnostic accuracy and Youden Index (J). The result showed that out of the total 303 individuals examined, a total malaria prevalence of 67.0% and 68.0% were recorded for micr oscopy and RDT, respectively. Additionally, the sensitivity (95% C.I), specificity (95% C.I), PPV (95% C.I), and NPV (95% C.I) of RDT compared to microscopy were 97.54 (94.36-98.94), 92.00 (85.00-95.89), 96.12 (92.53-98.02), and 94.85 (88.50- 97.78), respectively. The diagnostic accuracy (95% C.I) and Youden Index (J) were 95.71 (92.77- 97.70) and 0.89, respectively. Conclusively, our study revealed that RDT continues to remain efficacious. Thus, while malaria diagnosis by microscopy which is the gold standard remains the major method of malaria detection, it should be complemented by rapid diagnostic test (RDT), particularly in high malaria endemic regions where mean parasite density of patients are usually high.

Ultrasensitive molecular tests for Plasmodium detection: applicability in control and elimination programs and reference laboratories.

ABSTRACTObjective.To evaluate molecular tools to detect low-level parasitemia and the five species of Plasmodium that infect humans for use in control and elimination programs, and in reference laboratories.Methods.We evaluated 145 blood samples from patients who tested positive by nested polymerase chain reaction (nPCR), from asymptomatic individuals and from the WHO Global Malaria Programme/United Kingdom National External Quality Assessment Service. Samples were assayed using the genus-specific RealStar® Malaria PCR Kit 1.0 (alt-Gen; altona Diagnostics) and the RealStar® Malaria Screen & Type PCR Kit (alt-S&T; altona Diagnostics). The results from the molecular tests were compared with those from quantitative PCR (qPCR), nPCR and thick blood smear.Results.The levels of parasitemia ranged from 1 to 518 000 parasites/µL, depending on the species. Compared with nPCR, alt-S&T had a sensitivity of 100%, except for identifying P. falciparum, for which the sensitivity was 93.94%. All samples positive by alt-Gen were also positive by nPCR. When comparing alt-Gen to qPCR, the sensitivity was 100% for P. vivax, P. malariae and P. falciparum. For all Plasmodium species, the correlation between cycle threshold values of alt-S&T and alt-Gen compared with qPCR was significant (P < 0.0001, Spearman’s test), with r = 0.8621 for alt-S&T and r = 0.9371 for alt-Gen. When all Plasmodium species were considered, there was a negative correlation between the level of parasitemia and real-time PCR cycle threshold values (P < 0.0001). In this study, only 2 of 28 samples from asymptomatic individuals were positive by thick blood smear; however, all 28 of these samples were positive by alt-S&T.Conclusions.The alt-Gen and alt-S&T assays are suitable for detecting submicroscopic infections for distinct epidemiological purposes, such as for use in surveys and reference laboratories, and screening in blood banks, which will contribute to global efforts to eliminate malaria.

Prevalence of Plasmodium falciparum Malaria among Children Residing in Urban and Peri-urban Settlements in Rivers State

Urban and peri-urban areas are considered to be at lower risk of malaria compared to rural areas because of improved housing, higher socioeconomic status, improved environmental sanitation, and a limited number of breeding sites for mosquitoes. Reports have shown that there is an increased prevalence of malaria in urban and peri-urban areas but it has not been established which of these areas is at risk. The aim of this study, therefore, is to determine the prevalence rate of Plasmodium falciparum malaria infection among children in urban and peri-urban areas of Rivers State. A total of 601 and 500 blood samples were collected from urban and peri-urban areas respectively and examined using standard microscopy technique for detection of malaria parasites in blood samples. From the urban area, 282 tested positive out of 601 blood samples that were examined, giving the prevalence rate of 47% while in the peri-urban settlement, a total of 210 out of 500 tested positive to Plasmodium falciparum giving the prevalence rate of 42%. When the age was considered, the highest prevalence was recorded in children between 1-3 years and 7-12 years in urban settlement while in peri-urban, the highest prevalence was recorded in children between the age of 4-6 years with a prevalence of 45% and 46% respectively. Although the prevalence rates are relatively high. There is no significant difference between the prevalence rate in urban areas and that of peri-urban areas. Conclusively, intensive efforts should be made in controlling malaria parasites not only in rural areas but also in urban and peri-urban areas in Rivers State.

EVALUATION OF PERFORMANCE OF TWO MONOPLEX QUANTITATIVE REAL TIME PCR ASSAYS IN COMPARISON TO MICROSCOPY FOR IDENTIFICATION OF MALARIA PARASITES.

Background: Microscopy is the gold standard for Malaria diagnosis with shortcomings such as false positives, false negatives,errors in species identification,and errors in enumeration of parasites.Quantitative real-time PCR (qPCR) has improved submicroscopic malaria diagnosis. This study evaluated the performance, concordance, correlation and methods agreement of two monoplex qPCR assays against expert malaria microscopy for the detection and enumeration of malaria parasites. Methods: This was a cross sectional study utilizing 127 archived blood samples collected from five provinces in Kenya. Malaria microscopy was conducted by two independent microscopists then 18S-rRNA-qPCR and non-18S-rRNA-qPCR assays were done to identify and quantify the infecting species.The sensitivity,specificity,and predictive values.Cohen Kappa value was used to quantify the method agreement and Bland Altman test was used to assess the bias and limits of agreement.Correlation between microscopy and qPCR parasite densities was determined by the Spearman's rank test. Statistical significance was taken at p&lt;0.05. Results: A higher sensitivity and a lower specificity were observed in all the three plasmodium species in non 18SrRNA-qPCR compared to 18S-rRNA-qPCR. The sensitivity and specificity of 18S-rRNA-qPCR was 91.3% and 75% in detection of P.falciparum,67.6% and 88.1% in detection of P.malariae,and 55.8% and 91.4% in detection of P.ovale.The sensitivity and specificity of non 18S-rRNA-qPCR was 99.1% and 66.7% in detection of P.falciparum,77.9% and 88.1% in detection of P. malariae, and 79.4% and 90.3% in detection of P. ovale. All the positive and negative predictive values were above 70% except the negative predictive value for 18S-rRNA-qPCR (47.4%).Kappa of more than 0.5 was observed between microscopy and both18S-rRNA-qPCR and non-18S-rRNA-qPCR in the detection of all three malaria parasites. The non-18S-rRNA-qPCR method had higher kappa &gt; 0.65,in all the three species compared to 18S-rRNA-qPCR method (kappa &lt; 0.55).There was a clear positive correlation between microscopy parasite density and the parasite densities estimated by the 18S-rRNA-qPCR and Non-18S-rRNA-qPCR (P&lt;0.001). Conclusion: The results showed that both monoplex realtime PCR methods demonstrated a high performance compared to microscopy proving to be better methods in the identification and speciation of malaria parasites especially of low parasitemia.The realtime PCR methods also had a positive correlation with parasite density and hence can be used in accurate determination of parasite densities when compared to microscopy. Therefore, this study recommends the utilization of realtime PCR methods in the detection,speciation and quantification of both microscopic and submicroscopic malaria parasites.

House design and risk of malaria, acute respiratory infection and gastrointestinal illness in Uganda: A cohort study.

House construction is rapidly modernizing across Africa but the potential benefits for human health are poorly understood. We hypothesised that improvements to housing would be associated with reductions in malaria, acute respiratory infection (ARI) and gastrointestinal illness in an area of low malaria endemicity in Uganda. Data were analysed from a cohort study of male and female child and adult residents (n = 531) of 80 randomly-selected households in Nagongera sub-county, followed for 24 months (October 4, 2017 to October 31, 2019). Houses were classified as modern (brick walls, metal roof and closed eaves) or traditional (all other homes). Light trap collections of mosquitoes were done every two weeks in all sleeping rooms. Every four weeks, we measured malaria infection (using microscopy and qPCR to detect malaria parasites), incidence of malaria, ARI and gastrointestinal illness. We collected 15,780 adult female Anopheles over 7,631 nights. We collected 13,277 blood samples of which 10.2% (1,347) were positive for malaria parasites. Over 958 person years we diagnosed 38 episodes of uncomplicated malaria (incidence 0.04 episodes per person-year at risk), 2,553 episodes of ARI (incidence 2.7 episodes per person-year) and 387 episodes of gastrointestinal illness (incidence 0.4 episodes per person-year). Modern houses were associated with a 53% lower human biting rate compared to traditional houses (adjusted incidence rate ratio [aIRR] 0.47, 95% confidence interval [CI] 0.32-0.67, p<0.001) and a 24% lower incidence of gastrointestinal illness (aIRR 0.76, 95% CI 0.59-0.98, p = 0.04) but no changes in malaria prevalence, malaria incidence nor ARI incidence. House improvements may reduce mosquito-biting rates and gastrointestinal illness among children and adults. For the health sector to leverage Africa's housing modernization, research is urgently needed to identify the healthiest house designs and to assess their effectiveness across a range of epidemiological settings in sub-Saharan Africa.

Residual attention learning network and SVM for malaria parasite detection

Residual attention learning network and SVM for malaria parasite detection

Detection of asymptomatic malaria in Asian countries: a meta-analysis of diagnostic accuracy

BackgroundAchieving malaria elimination requires the targeting of the human reservoir of infection, including those patients with asymptomatic infection. The objective was to synthesise evidence on the accuracy of the rapid-onsite diagnostic tests (RDTs) and microscopy for the detection of asymptomatic malaria as part of the surveillance activities in Asian countries.MethodsThis was a meta-analysis of diagnostic test accuracy. Relevant studies that evaluated the diagnostic performance of RDTs and microscopy for detection of asymptomatic malaria were searched in health-related electronic databases. The methodological quality of the studies included was assessed using the QUADAS-2 tool.ResultsTen studies assessing RDT and/or microscopy were identified. The diagnostic accuracies in all these studies were verified by PCR. Overall, the pooled sensitivities of RDT, as well as microscopy for detection of any malaria parasites in asymptomatic participants, were low, while their pooled specificities were almost ideal. For the detection of Plasmodium falciparum, pooled sensitivity by RDT (59%, 95%CI:16–91%) or microscopy (55%, 95%CI: 25–82%) were almost comparable. For detection of Plasmodium vivax, pooled sensitivity of RDT (51%, 95% CI:7–94%) had also the comparable accuracy of microscopy (54%, 95%CI,11–92%). Of note are the wide range of sensitivity and specificity.ConclusionThe findings of this meta-analysis suggest that RDTs and microscopy have limited sensitivity and are inappropriate for the detection of asymptomatic Plasmodium infections. Other methods including a combination of PCR-based strategies, Loop-Mediated Isothermal Amplification (LAMP) technique must be considered to target these infections, in order to achieve malaria elimination. However, more data is needed for the wide acceptance and feasibility of these approaches. Studies to explore the role of asymptomatic and sub-patent infections in the transmission of malaria are of critical importance and are recommended.

Limited Reliability of the Molecular Detection of Plasmodium spp. from Incubated Blood Culture Samples for Forensic Purposes.

The suitability of incubated blood culture material for forensic molecular malaria diagnosis was assessed for non-endemic settings for cases in which the differential diagnosis malaria was initially overlooked. For the proof-of-principle assessment, residual blood culture materials from febrile patients from tropical Ghana were investigated by real-time PCR and compared with available historic microscopic results. In 2114 samples, for which microscopical results and real-time PCR results were available, microscopical results comprised 711 P. falciparum detections, 7 P. malariae detections, 1 microscopically not-further-discriminable Plasmodium spp. detection as well as 13 detections of mixed infections comprising 12 cases of P. falciparum/P. malariae co-infections and 1 case of a P. falciparum/P. ovale complex co-infection, while real-PCR indicated 558 P. falciparum detections, 95 P. malariae detections, 10 P. ovale complex detections, 1 P. vivax detection and 4 detected P. falciparum/P. malariae co-infections. Concordance of routine microscopy and real-time PCR was imperfect. Using routine microscopy as reference was associated with a seemingly low agreement of positive real-time PCR results of 90.9%. However, if positive samples, either by routine microscopy or real-time PCR or both, were applied as a combined reference, the agreement of positive results obtained with real-time PCR was increased from 74.0% to 77.9%, while the agreement of positive results obtained with routine microscopy was decreased from 100% to 85.3%. The predictive value of routine microscopy for negative results in the reference was slightly better with 90.9% compared to real-time PCR with 86.9%; the concordance between routine microscopy and real-time PCR was imperfect. In conclusion, even suboptimal sample materials such as incubated blood culture materials can be applied for forensic malaria diagnosis, if more suitable sample materials are not available, but the molecular detection rate of positive results in routine microscopy is much lower than previously reported for non-incubated blood.

Impact of malaria prophylaxis on Plasmodium Parasitemia among pregnant women receiving care at Federal Medical Centre, Owerri

Background: Malaria during pregnancy harms the baby's health. As personal protection and chemoprevention therapy, insecticide-treated nets (ITN) and intermittent preventive treatment (IPTps) of malaria during pregnancy are recommended. According to the World Health Organization, the introduction of IPTp and ITN constituted a defining moment in malaria prevention in endemic areas during pregnancy. The purpose of this research was to see if there was an association between the usage of IPTp and ITNs and maternal malaria prophylaxis. Methods: A cross-sectional study was conducted on 327 pregnant women who presented at the federal medical center in Owerri. Participants' blood samples were taken for microscopic inspection to detect malaria parasites using established procedures. Pregnant women provided information on their use of IPTp and ITN. Descriptive statistics were used to characterize the independent variables, and chi-square was used for categorical variables as needed using Microsoft Excel 2016. Results: There was a significant association between IPTp use in the prevention of malaria in pregnancy (P-Value = &lt;0.001) and ITN use in the prevention of malaria in pregnancy respectively (P-Value = &lt;0.001). Conclusions: Maternal Malaria is a major public health issue that poses severe danger to pregnant women and their fetuses. IPTp and ITN use are beneficial in malaria prevention among this population.

A Novel Data Augmentation Convolutional Neural Network for Detecting Malaria Parasite in Blood Smear Images

ABSTRACT Malaria fever is a potentially fatal disease caused by the Plasmodium parasite. Identifying Plasmodium parasites in blood smear images can help diagnose malaria fever rapidly and precisely. According to the World Health Organization (WHO), there were 241 million malaria cases and 627 000 deaths worldwide in 2020, while 95% of malaria cases and 96% of malaria deaths occurred in Africa. Also in Africa, children that are less than five years old accounted for an estimated 80% of all malaria deaths. To address the menace of malaria, this paper proposes a novel deep learning model, called a data augmentation convolutional neural network (DACNN), trained by reinforcement learning to tackle this problem. The performance of the proposed DACNN model is compared with CNN and directed acyclic graph convolutional neural network (DAGCNN) models. Results show that DACNN outperforms previous studies in processing and classification images. It achieved 94.79% classification accuracy in malaria blood sample images of balanced class dataset obtained from the Kaggle dataset. The proposed model can serve as an effective tool for the detection of malaria parasites in blood smear images.

Detection of Plasmodium vivax using Automated Hematology Analyzer in the Korean Army.

This study aimed to evaluate whether our equation model developed from the Sysmex hematology analyzer can discriminate patients with Plasmodium vivax (P. vivax) infection from those with acute febrile illness (AFI) and healthy controls. Besides, we compared our model with the previously studied models. A total of 312 blood samples were collected from the P. vivax, AFI, and healthy control groups. All samples were tested for routine complete blood count conducted by using a Sysmex XE-2100 or XE-5000 analyzer. We compared the reportable and research parameters generated from the Sysmex analyzer among the three groups. The selected parameters that showed a significant difference between the P. vivax and the other group were included in the logistic regression analysis to develop our model (N-OIpv model). Moreover, we analyzed the CBC data according to the previous models, such as the presence of abnormal blue coded events in the WBC/BASO scattergram called the observer-interpretation (OIpv) model, and the previous equation model (N-OD1pv model) developed by Campuzano-Zuluaga et al. Results: The N-OIpv model, which consists of three parameters, such as mean cell volume, plateletcrit, and Lymph-X, showed the best performance for detection of malaria (97.4% accuracy). Also, this model can increase the sensitivity by about 11.9% to 18.1% compared with the OIpv and N-OD1pv models, respectively. We concluded that the N-OIpv model using the Sysmex hematology analyzer is a useful diagnostic tool in the routine laboratory workup for malaria.

Intelligent Deep Transfer Learning Based Malaria Parasite Detection and Classification Model Using Biomedical Image

Malaria is a severe disease caused by Plasmodium parasites, which can be detected through blood smear images. The early identification of the disease can effectively reduce the severity rate. Deep learning (DL) models can be widely employed to analyze biomedical images, thereby minimizing the misclassification rate. With this objective, this study developed an intelligent deep-transfer-learning-based malaria parasite detection and classification (IDTL-MPDC) model on blood smear images. The proposed IDTL-MPDC technique aims to effectively determine the presence of malarial parasites in blood smear images. In addition, the IDTL-MPDC technique derives median filtering (MF) as a pre-processing step. In addition, a residual neural network (Res2Net) model was employed for the extraction of feature vectors, and its hyperparameters were optimally adjusted using the differential evolution (DE) algorithm. The k-nearest neighbor (KNN) classifier was used to assign appropriate classes to the blood smear images. The optimal selection of Res2Net hyperparameters by the DE model helps achieve enhanced classification outcomes. A wide range of simulation analyses of the IDTL-MPDC technique are carried out using a benchmark dataset, and its performance seems to be highly accurate (95.86%), highly sensitive (95.82%), highly specific (95.98%), with a high F1 score (95.69%), and high precision (95.86%), and it has been proven to be better than the other existing methods.

Socio-Demographic Profile, Asymptomatic Malaria Parasitaemia and Glycemic Control among Midled-Aged and Elderly Type 2 Diabetes Mellitus Patients in Rural Southwestern Nigeria: A Cross Sectional Study

The main therapeutic goal for all type 2 diabetes mellitus (T2DM) patients is to maintain good control so as to prevent the risk of complications associated with poor control. This study determined the prevalence of poor control and its association with socio-demographics and malaria parasitaemia among middle aged and elderly T2DM patients at a tertiary hospital in rural Southwestern Nigeria. We conducted a retrospective observational study on 250 T2DM using semi-structured interviewer administered questionnaire. Venous blood samples were collected and processed for glycated hemoglobin sugar estimation and malaria parasite detection by microscopy. Data were analyzed using SPSS version 20.0. Multivariate logistic regression identified the association of socio-demographics and asymptomatic malaria parasitaemia with poor control. The prevalence of poor glycemic control was 31.6% (95%CI: 34.4%-45.8%). Old age, (AOR=4.868; 95% CI: 1.258-24.574), female genders (AOR=7.100; 95% CI: 1.875-34.655), no formal education (AOR=3.447; 95% CI: 1.098-21.478), presence of malaria parasitaemia (AOR=48.423; 95% CI: 4.987-411.366), and higher parasite density (AOR=7.102; 95% CI: 1.785-15.002), were significantly associated with poor control. Health facilities should integrate screening of malaria parasitaemia into the management of T2DM patients while also exploring other barriers of poor control.

Deep Learning for Real-Time Malaria Parasite Detection and Counting Using YOLO-mp

Deep Learning for Real-Time Malaria Parasite Detection and Counting Using YOLO-mp

Laser-Induced Surface Acoustic Wave Sensing-Based Malaria Parasite Detection and Analysis

Malaria parasite- <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Plasmodium falciparum</i> infection is a severe healthcare problem in tropical and subtropical regions. Early detection of such disease is vital in reducing mortality and controlling the spread in the affected areas. In this article, detecting the ring-stage malaria parasite is carried out by using the proposed photoacoustic (PA)-surface acoustic wave (SAW) sensing and detection system. By optical radiation, the PA signal is generated from the red blood cell (RBC), and then, the SAW sensor could transfer the acoustic wave into the electrical signal for the analysis. The SAW sensor is manufactured via the standard two-step lithography techniques. The proposed system consists of a tunable pulse laser device with the adjusting optical components, a PA-SAW sensor, a function generator, two analog front-end (AFE) circuits, a digital oscilloscope, a workstation for data postprocessing, and several auxiliary coaxial cables for data communications. With the acquired PA signal and its fast Fourier transform (FFT) spectrum from the various specimens, the cultured ring-stage malaria parasite in the infected whole blood could be detected at a low concentration level of 0.5% with the PA-SAW sensor. The proposed system demonstrates its excellent potential in the early diagnosis of the malaria parasite.

Occurrence and clinical features of HIV and malaria in co-infected individuals in Osun State, Nigeria.

Human immunodeficiency virus (HIV) and malaria infections are among the major public health concerns in sub-Saharan Africa, where they are associated with high morbidity and mortality. The study was conducted to assess the occurrence and clinical features of HIV and malaria in co-infected individuals in Osun State, Nigeria. The study was cross-sectional, which involved 422 participants who were administered structured questionnaires for socio-demographic and clinical data. Venous blood was collected for malaria parasite detection and count from One hundred and seventy-four HIV seropositive individuals. They were re-examined clinically for HIV diagnosis, CD4 + T cell counts, and packed cell volume (PCV). The mean age of the participants was 28.48 ± 15.38 while the overall predominance of malaria among the HIV-positive patients was 11.5% (20/174). The malaria prevalence was significantly higher in female patients (P = 0.0088) and occupational status among students (P = 0.0001). Malaria/HIV co-infected patients had a significantly lower mean value of PCV (P = 0.0001), CD4 + cell count (0.0001), and temperature (0.0001) compared to HIV-infected patients having no malaria. The study showed that females had relatively higher malaria infection compared to their male counterparts. To achieve better management of HIV patients against malaria infection, proper preventive measures, antiretroviral therapy (ART), and chemoprophylaxis are a useful strategy to put in place. Also, the monitoring of CD4 + cell count, viral load, and some hematology indices on a regular basis is crucial.

Malaria infection and its association with socio-demographics, preventive measures, and co-morbid ailments among adult febrile patients in rural Southwestern Nigeria: A cross-sectional study.

Objectives:The study determined the prevalence of malaria infection and its association with socio-demographics, environmental, housing, and co-morbid ailment factors.Methods:The study was a cross-sectional of 330 consented adult febrile patients who were recruited at a tertiary health facility in rural Southwestern Nigeria. The standardized interviewer-administered questionnaire sought information on their socio-demographics, environmental, housing, and co-morbid ailment factors. Venous blood samples were collected and processed for malaria parasite detection, retroviral screening, glycated hemoglobin, and hemoglobinopathy. Data were analyzed using SPSS version 20. The strength of the association between independent and dependent variables was measured using odds ratio and 95% confidence interval with a significant level (p value <0.05).Results:The prevalence of malaria parasitemia was 63.3% (95% confidence interval: 57.9%–68.5%). Being a farmer (p = 0.002), lack of formal education (p = 0.043), low-income earners (p = 0.031), presence of bushes (p = 0.048), stagnant water (p = 0.042), not sleeping under long-lasting insecticide-treated nets (p < 0.001), and sickle cell disease (p = 0.041) were significantly associated with malaria infection.Conclusion:The study revealed that there is a high prevalence of malaria infection in rural Southwestern Nigeria. There may be a need to pay greater attention to adult populations in rural areas for malaria intervention and control programs.

An algorithm based on molecular protocols to improve the detection of Plasmodium in autochthonous malarial areas in the Atlantic Forest biome

ABSTRACTMalaria is the most important vector-borne disease in the world and a challenge for control programs. In Brazil, 99% of cases occur in the Amazon region. In the extra-Amazonian region, a non-endemic area, epidemiological surveillance focuses on imported malaria and on autochthonous outbreaks, including cases with mild symptoms and low parasitemia acquired in the Atlantic Forest biome. In this scenario, cases are likely to be underreported, since submicroscopic parasitemias are not detected by thick blood smear, considered the reference test. Molecular tests are more sensitive, detecting asymptomatic individuals and mixed infections. The aim of this study was to propose a more efficient alternative to detect asymptomatic individuals living in areas of low malaria endemicity, as they are reservoirs of Plasmodium that maintain transmission locally. In total, 955 blood samples from residents of 16 municipalities with autochthonous malaria outbreaks in the Sao Paulo State were analyzed; 371 samples were collected in EDTA tubes and 584 in filter paper. All samples were initially screened by a genus-specific qPCR targeting ssrRNA genes (limit of detection of 1 parasite/µL). Then, positive samples were subjected to a nested PCR targeting ssrRNA and dihydrofolate reductase-thymidylate synthase genes (limit of detection of 10 parasites/µL) to determine Plasmodium species. The results showed a statistically significant difference (K = 0.049; p < 0.0001) between microscopy positivity (6.9%) and qPCR (22.9%) for EDTA-blood samples. Conversely, for samples collected in filter paper, no statistical difference was observed, with 2.6% positivity by thick blood smear and 3.1% for qPCR (K = 0.036; p = 0.7). Samples positive by qPCR were assayed by a species-specific nested PCR that was in turn positive in 26% of samples (16 P. vivax and 4 P. malariae ). The results showed that molecular protocols applied to blood samples from residents in areas with autochthonous transmission of malaria were useful to detect asymptomatic patients who act as a source of transmission. The results showed that the genus-specific qPCR was useful for screening positives, with the subsequent identification of species by nested PCR. Additional improvements, such as standardization of blood plotting on filter paper and a more sensitive protocol for species determination, are essential. The qPCR-based algorithm for screening positives followed by nested PCR will contribute to more efficient control of malaria transmission, offering faster and more sensitive tools to detect asymptomatic Plasmodium reservoirs.

SENSITIVITY AND SPECIFICITY OF LAMP IN DETECTING MALARIA PARASITE INFECTION IN ENDEMIC AREAS OF BINH PHUOC PROVINCE IN 2017

The study was conducted in two communes of the mesoendemic malaria area of Binh Phuoc province, using the giemsa technique and LAMP technique to detect malaria parasites. The purpose of the study was to determine the prevalence of malaria parasites in the community and to evaluate the sensitivity, specificity and predictive value of LAMP compare giemsa technique (gold standard). As a result, 384 samples of human blood were collected and analyzed: The prevalence of malaria parasitic by giemsa was 0.52% (2/384) and LAMP was 4.43 % (17/384). The sensitivity of the LAMP technique was 100% (02/02), the specificity was 96.07% (367/382). Positive predictive value was 11.76% (2/17), negative predictive value was 100% (367/367).

Malaria Parasitaemia and Intervention Measures amongst Pregnant Women in Delta State, Nigeria

Pregnant women and children under the age of five are mostly affected because of their level of immunity. WHO have outlines various intervention measures for the control of malaria which include the use of long-lasting insecticidal treated nets, indoor residual spraying, intermittent preventive treatment and prompt and early treatments of confirmed cases. The aim of this study is to evaluate malaria parasitaemia and the level of compliance to the various WHO intervention measures in Delta State. 5ml of venous blood was drawn from 1000 consenting pregnant women attending antenatal clinics in Delta State, Nigeria. Malaria parasite detection was done by microscopic examination of thin and thick blood films. Intervention measures were evaluated using a structured questionnaire, data obtained was analysed using measures of central tendency and student T-test. Out of the 1000 pregnant women examined, 624 (62.4%) tested positive for the P. falciparum parasite with the age group; 21-30 year having the highest prevalence of 70.9%. Primigravidae had the highest prevalence of 68.9% while women in their first trimester had (80.6%) prevalence. Women that slept under insecticide treated nets had a prevalence of 156 (46.6%), intermittent preventive treatment had 109(56.5%), indoor residual spraying had 186 (79.49%), early diagnosis and prompt treatment had 47 (74.60%) prevalence. Pregnant women should be encouraged on the use of various WHO intervention through health education.