Malaria Microscopy Research Articles

Clinical management and outcomes of acute febrile illness in children attending a tertiary hospital in southern Ethiopia

BackgroundThe management of febrile illnesses is challenging in settings where diagnostic laboratory facilities are limited, and there are few published longitudinal data on children presenting with fever in such settings. We have previously conducted the first comprehensive study of infectious aetiologies of febrile children presenting to a tertiary care facility in Ethiopia. We now report on clinicians’ prescribing adherence with guidelines and outcomes of management in this cohort.MethodsWe consecutively enrolled febrile children aged 2 months and under 13 years, who were then managed by clinicians based on presentation and available laboratory and radiologic findings on day of enrolment. We prospectively collected outcome data on days 7 and 14, and retrospectively evaluated prescribing adherence with national clinical management guidelines.ResultsOf 433 children enrolled, the most common presenting syndromes were pneumonia and acute diarrhoea, diagnosed in 177 (40.9%) and 82 (18.9%), respectively. Antibacterial agents were prescribed to 360 (84.7%) of 425 children, including 36 (34.0%) of 106 children without an initial indication for antibacterials according to guidelines. Antimalarial drugs were prescribed to 47 (11.1%) of 425 children, including 30 (7.3%) of 411 children with negative malaria microscopy. Fever had resolved in 357 (89.7%) of 398 children assessed at day 7, and in-hospital death within 7 days occurred in 9 (5.9%) of 153 admitted patients. Among children with pneumonia, independent predictors of persisting fever or death by 7 days were young age and underweight for age. Antibacterial prescribing in the absence of a guideline-specified indication (overprescribing) was more likely among infants and those without tachypnea, while overprescribing antimalarials was associated with older age, anaemia, absence of cough, and higher fevers.ConclusionOur study underscores the need for improving diagnostic support to properly guide management decisions and enhance adherence by clinicians to treatment guidelines.

Caregivers’ vector control methods and its effect on malaria infection in febrile children presenting in a Tertiary Hospital in Nigeria

Background: Malaria is a major public health problem in sub-Saharan Africa. Several efforts are being made to reduce its prevalence and morbidity in Nigerian children with emphasison vector control measures.Methods: This was acrosssectional descriptive study conducted on 382 febrile children seen at a tertiary hospital in Nigeria over an eight-month period. A structured questionnaire was used to collect information on sociodemographic, vector control measures and care given to the subjects. Investigations conducted included malaria microscopy and total leukocyte count.Results: Eighty percent (308/382) employed at least one vector controlmeasures to prevent malaria infection, and majority 232 (75.2%) use only one control measure. The commonest control measures used included always keeping doors and windows shut 298 (96.7%) and/or netted 280 (90.9%), use of conventional insecticide sprays 183 (59.4%), use of insecticide treated bed nets (ITNs) 178 (57.8%) and ensuring child sleeps at night with body adequately covered 77(25%). Approximately half (178/315) of households who owned ITN used it, and only 40.4% (72/178) used it daily. It was noted that children that slept under an insecticide treated bed net (RR 0.56, 95% CI 0.33-0.94; P=0.029) and those who slept well covered at night (RR 0.26, 95% CI 0.12-0.61; P=0.002) had less risk of malaria infection. The use insecticide treated bed net however lost significance following adjustment for other control measures used and socio-demographic factors of interest (RR 0.63, 95% CI 0.36-1.10;P=0.101).Conclusion: There is need to intensify education on appropriate malaria control measures especially proper use of insecticide-treated nets and suitable clothing during sleep at night.

W066 Comprehensive performance assessment of malaria microscopists and laboratory diagnostic service capacity in districts stratified for malaria elimination in Ethiopia

W066 Comprehensive performance assessment of malaria microscopists and laboratory diagnostic service capacity in districts stratified for malaria elimination in Ethiopia

Nutritional status of children under five years old involved in a seasonal malaria chemoprevention study in the Nanyumbu and Masasi districts in Tanzania.

BackgroundMalnutrition and malaria are common co-morbidities in low-income countries, especially among under-fives children. But the malnutrition situation in Masasi and Nanyumbu districts, its interaction with malaria infection and the influence of socioeconomic factors are not well understood.MethodsChildren aged between 3–59 months in Masasi and Nanyumbu were screened for nutritional status and malaria infection in the community. Nutritional status was determined using age and anthropometric parameters. Z-scores (weight for age (WAZ), height for age (HAZ) and weight for height (WHZ)) were calculated based on the World Health Organisation (WHO) growth reference curves. Malaria infection was determined using malaria rapid diagnostic test and microscopy. Hemoglobin concentration was assessed using HemoCue spectrophotometer, and anemia was classified as hemoglobin concentration < 11.0g/dL. Structured questionnaire was used to collect socio- demographic information electronically.ResultsA total of 2242 children, 1539 (68.6%) from Masasi and 1169 (52.1%) females were involved in the study. The mean z-scores (WAZ = -0.60 and HAZ = -1.56) were lower than the WHO reference population. The overall prevalence of malnutrition was 49%, and it was significantly higher in Nanyumbu (52.5%) than in Masasi (47.3%), (x2 = 5.045, p = 0.025). Prevalence of malnutrition was higher in boys (53.0%) than in girls (45.0%) (x2 = 13.9, p < 0.001). Stunting was the most prevalent component of undernutrition; it was slightly prevalent in Nanyumbu (46.5%) compared to Masasi (42.0%), (x2 = 3.624, p = 0.057) and in boys (48.2%) than in girls (39.1%), x2 = 17.44, p<0.001. Only 15.8% of the undernourished children had malaria infection. Sex, age group and anaemia were significantly associated with undernourishment (p<0.05), while district and malaria infection were marginally (p≤0.06) associated with undernourishment. None of the undernutrition indices was associated with malaria infection.ConclusionUndernutrition was highly prevalent in the study population and was influenced sex, age, anaemia and malaria infection. More emphasis is needed to address the malnutrition problem especially stunting in Masasi and Nanyumbu districts.

Field evaluation of the diagnostic performance of EasyScan GO: a digital malaria microscopy device based on machine-learning

BackgroundMicroscopic examination of Giemsa-stained blood films remains the reference standard for malaria parasite detection and quantification, but is undermined by difficulties in ensuring high-quality manual reading and inter-reader reliability. Automated parasite detection and quantification may address this issue.MethodsA multi-centre, observational study was conducted during 2018 and 2019 at 11 sites to assess the performance of the EasyScan Go, a microscopy device employing machine-learning-based image analysis. Sensitivity, specificity, accuracy of species detection and parasite density estimation were assessed with expert microscopy as the reference. Intra- and inter-device reliability of the device was also evaluated by comparing results from repeat reads on the same and two different devices. This study has been reported in accordance with the Standards for Reporting Diagnostic accuracy studies (STARD) checklist.ResultsIn total, 2250 Giemsa-stained blood films were prepared and read independently by expert microscopists and the EasyScan Go device. The diagnostic sensitivity of EasyScan Go was 91.1% (95% CI 88.9–92.7), and specificity 75.6% (95% CI 73.1–78.0). With good quality slides sensitivity was similar (89.1%, 95%CI 86.2–91.5), but specificity increased to 85.1% (95%CI 82.6–87.4). Sensitivity increased with parasitaemia rising from 57% at < 200 parasite/µL, to ≥ 90% at > 200–200,000 parasite/µL. Species were identified accurately in 93% of Plasmodium falciparum samples (kappa = 0.76, 95% CI 0.69–0.83), and in 92% of Plasmodium vivax samples (kappa = 0.73, 95% CI 0.66–0.80). Parasite density estimates by the EasyScan Go were within ± 25% of the microscopic reference counts in 23% of slides.ConclusionsThe performance of the EasyScan Go in parasite detection and species identification accuracy fulfil WHO-TDR Research Malaria Microscopy competence level 2 criteria. In terms of parasite quantification and false positive rate, it meets the level 4 WHO-TDR Research Malaria Microscopy criteria. All performance parameters were significantly affected by slide quality. Further software improvement is required to improve sensitivity at low parasitaemia and parasite density estimations.Trial registration ClinicalTrials.gov number NCT03512678.

MOLECULAR DETECTION OF THE PLASMODIUM FALCIPARUM OBTAINED FROM OUT-PATIENTS FROM SELECTED HOSPITALS IN KADUNA STATE

Molecular detection of Plasmodium falciparum based on PCR amplification is generally very specific and sensitive test for determining the species of Plasmodium present in the blood of an individual than the microscopy-based diagnosis from blood smears. Thirty-two (32) microscopic malaria positive blood samples were collected from some patients between November 2013 to March 2014 from three major hospitals.Plasmodium DNA was extracted from the 32 blood samples collected from the malaria-positive patients confirmed by microscopy and the DNA amplification was done by using Polymerase Chain Reaction (PCR). The amplified COX3 gene of each malaria isolates were further characterized using Agarose gel electrophoresis while sequence identification was performed by using GenBank’s BLAST algorithm. After the completion of the agarose gel electrophoresis the bands indicating amplified Cox3 gene by PCR was observed in four (4) plasmodium positive blood samples out of the 32 samples analyzed. Amplified band for COX3 gene was located at 300bp position on the DNA ladder on the agarose gel plate for sample 1, 9 and 24 all from Kagarko general hospital while sample 28 was from GwannaAwan general hospital. The BLAST results showed that the P. falciparum DNA sequences aligned at 98-99% similarity with those deposited in the GenBank confirming the parasite isolated from the patients were P. falciparum. The use of PCR diagnosis to compliment microscopy examination of stained blood smears in our medical centres is strongly recommended so that an accurate detection of malaria parasites in blood will help to institute proper drug therapy

Plasmodium falciparum\xa0multiplicity of infection and pregnancy outcomes in Congolese women from southern Brazzaville, Republic of Congo

BackgroundInvestigating whether the multiplicity of Plasmodium falciparum infection (MOI) is related to pregnancy outcomes, is of interest in sub-Saharan area where malaria is highly endemic. The present study aimed to characterize the genetic diversity of P. falciparum in women at delivery from Southern Brazzaville, and investigate whether the MOI is associated with maternal anaemia, preterm delivery, or low birth weight.MethodsThis was a cross sectional study carried out with samples collected between March 2014 and April 2015 from 371 women recruited at delivery at a Health Centre in southern Brazzaville, Republic of Congo. Matched peripheral, placental, and cord blood collected from each of the women at delivery were used for the detection of P. falciparum microscopic and submicroscopic parasitaemia, and parasite DNA genotyping by nested PCR.ResultsFrom 371 recruited women, 27 were positive to microscopic malaria parasitaemia while 223 women harboured submicroscopic parasitaemia. All msp-1 block 2 family allelic types (K1, MAD20 and RO33) were observed in all the three compartments of blood, with K1 being most abundant. K1 (with 12, 10, and 08 alleles in the peripheral, placental, and cord blood respectively) and MAD20 (with 10, 09, and 06 alleles in the respective blood compartments) were more diverse compared to RO33 (with 06, 06, and 05 alleles in the respective blood compartments). From the 250 women with microscopic and/or submicroscopic parasitaemia, 38.5%, 30.5%, and 18.4% of peripheral, placental and cord blood sample, respectively, harboured more than one parasite clone, and polyclonal infection was more prevalent in the peripheral blood of women with microscopic parasitaemia (54.5%) compared to those with submicroscopic parasitaemia (36.7%) (p = 0.02). The mean multiplicity of genotypes per microscopic and submicroscopic infection in peripheral blood was higher in anemic women (2.00 ± 0.23 and 1.66 ± 0.11, respectively) than in non-anaemic women (1.36 ± 0.15 and 1.45 ± 0.06, respectively) (p = 0.03 and 0.06). In logistic regression, women infected with four or more clones of the parasite were 9.4 times more likely to be anaemic than women harbouring one clone. This association, however, was only observed with the peripheral blood infection. No significant association was found between the MOI and low birth weight or preterm delivery.ConclusionsThese results indicate that the genetic diversity of P. falciparum is high in pregnant women from southern Brazzaville in the Republic of Congo, and the multiplicity of the infection might represent a risk for maternal anaemia.

Current status of 4-aminoquinoline resistance markers 18 years after cessation of chloroquine use for the treatment of uncomplicated falciparum malaria in the littoral coastline region of Cameroon

ABSTRACT The onset and rapid spread of chloroquine resistance and the introduction of amodiaquine for the treatment of uncomplicated malaria in Cameroon have influenced the proportion of Plasmodium falciparum sensitive and resistant alleles related to 4-aminoquinoline drugs. This study was undertaken to determine the prevalence of resistance markers to antimalarial 4-aminoquinolines in Douala in the Littoral Region, and Buea in the South West Region in June 2020. Dry blood spots were prepared from malaria microscopy positive cases and used for parasite DNA extraction by chelex-100 method. Plasmodium species identification was carried out by PCR amplification/agarose gel electrophoresis of 18srRNA. The Pfcrt and Pfmdr1 genes were amplified by PCR followed by restriction digestion. The prevalence of single nucleotide polymorphisms (SNPs) was compared between study sites and with previous studies carried out between 2003–2005 and 2009–2011 using the Chi square test. The results showed that Plasmodium falciparum was the dominant species occurring as mono-infections (84.6%). The wild type K76 allele of the Pfcrt gene was found in 74.9% of isolates while the wild N86, Y184 and D1246 alleles of the Pfmdr1 gene were found respectively in 87.2%, 89.6% and 100% of field isolates. The results showed a significant reduction in the mutant alleles compared to results obtained in 2003–2005 and 2009–2013. The KNYD haplotype was observed to be the most prevalent. The results indicated that there is a gradual erosion of the mutant Pfcrt and Pfmdr1 genotype and a gradual return to the sensitive P. falciparum genotype in Cameroon.

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.

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.

Assessing malaria staining practices with Giemsa for malaria microscopy; a case of selected laboratory facilities in the Ashanti region of Ghana

BackgroundMicroscopy remains the gold standard for malaria diagnosis globally, especially where quality Giemsa stain is used. However, several Giemsa stains products have flooded the Ghanaian market which may not meet the required standard. In this study we report on the efficacy of Giemsa stains used for malaria detection in selected medical laboratories in Ashanti region. MethodologyA questionnaire was administered to obtain data of staining practices among participants. Thick and thin blood smears with standard parasite density of 300,000 parasites/ul ± 25,000 was given to facilities for staining. The stained slides were examined for their staining characteristics of the white blood cells, malaria parasites and parasite density by certified malaria microscopists. ResultsLess than 40% of the participant had parasite density within the expected range (225,000-375,000/ul). Forty percent (40%) also scored less than 7 out of 10 on the staining characteristics of the white blood cells. Additionally, 73.3% of participating laboratories used tap water for preparation of Giemsa working solution which affected parasite negatively. A statistically significant association was observed between immediate preparations of working solution and the morphological changes of neutrophils (p<0.0001). ConclusionThe study found that a less than half (40%) of Giemsa products used in Ghanaian medical laboratory facilities were adequately effective in detecting in malaria parasites optimally. This poses a great threat to malaria diagnosis in Ghana.

Congenital cerebral malaria: a masquerader in a neonate

BackgroundCongenital malaria, which is caused by vertical transmission of malaria parasites, is a potentially fatal condition. Despite Africa’s high malaria burden, congenital malaria is not routinely screened for, and thus may go undiagnosed. Malaria, if not treated promptly, can quickly progress to severe forms and result in death. Severe congenital malaria is believed to be uncommon in neonates due to maternal antibodies, fetal haemoglobin, and the placenta’s sieving effect. The majority of reported cases were classified as having severe anaemia. Following a thorough review of the literature, only one case of congenital cerebral malaria (CCM) has been reported, and it was misdiagnosed.Case presentationA 5-day-old Nigerian neonate born to an apparently healthy mother initially displayed characteristics consistent with neonatal sepsis and severe neonatal hyperbilirubinaemia. He quickly developed characteristics consistent with meningitis. Surprisingly, the peripheral blood film revealed evidence of malaria parasites, which was immediately confirmed by Giemsa-stained thick and thin blood film microscopy for malaria. The patient was diagnosed with congenital cerebral malaria. The medication was modified to parenteral artesunate followed by oral artemisinin combination therapy. The neonate recovered fully and had no neurological deficits on follow up.ConclusionBecause CCM and infant meningitis have similar clinical presentations, CCM could be misdiagnosed and lead to death if there isn’t a high index of suspicion.

Malaria in the First Trimester of Pregnancy and Fetal Growth: Results from a Beninese Preconceptional Cohort.

Malaria in early pregnancy occurs at a time when the placenta is developing, with possible consequences for placental function and fetal growth. We assessed the association between first trimester malaria and fetal growth documented through repeated ultrasound scans. The RECIPAL preconceptional cohort included 411 Beninese pregnant women followed from 7 weeks' gestation (wg) until delivery. Among them, 218 had 4 scans for fetal monitoring at 16, 22, 28, and 34 wg. Multivariate seemingly unrelated regression models were used to assess association of microscopic malaria in the first trimester (<15 wg) with abdominal circumference, head circumference, biparietal diameter, and femur length throughout pregnancy. Of 39% (86/218) of women with at least 1 microscopic malarial infection during pregnancy, 52.3% (45/86) were infected in the first trimester. Most women (88.5%) were multiparous. There was no association between adjusted z-scores for fetal growth parameters and first trimester malaria. Parity, newborn sex, socioeconomic level, and maternal body mass index significantly influenced fetal growth. In a context where malaria infections in pregnancy are well detected and treated, their adverse effect on fetal growth may be limited. Our results argue in favor of preventing and treating infections as early as the first trimester.

The Prevalence of Dengue Virus and Malaria Co-Infection among HIV-Infected Patients within South Eastern Nigeria

Background: Dengue and malaria are infections of great public health concern, especially in tropical countries like Nigeria where the burden of HIV infection is high. This study was conducted to determine the seroprevalence of dengue virus and dengue/malaria coinfection among febrile HIV-infected patients attending the University of Nigeria Teaching Hospital and Nnamdi Azikiwe University teaching university both in the southeastern region of Nigeria. Methods: In this cross-sectional study, blood samples from 338 consenting HIV-infected patients were collected and tested for plasmodiasis and DENV using malaria microscopy and ELISA, respectively. Interviewer-based questionnaires were used to assess subjects’ sociodemographic variables and dengue risk factors. This study was conducted within the peak period of the dry season (January-February 2016). Results: Of the 338 screened participants, 13.02% were seropositive for DENV, whereas 55.8% were positive for Plasmodium spp. About 2.7% were positive for both dengue virus and Plasmodium spp. The overall seroprevalence of dengue virus by NS1 antigenemia, IgM and IgG antibodies was 9.5%, 5.6% and 8%. Conclusion: The high prevalence of malaria and DENV indicates the need to strengthen vector control and dengue surveillance programs.

High prevalence of asymptomatic Plasmodium falciparum malaria in Makenene, a locality in the forest-savannah transition zone, Centre Region of Cameroon

Malaria transmission and prevalence is still not well documented across Cameroon particularly in medium-sized cities or localities representing high transit zone. Different risk factors could be associated with persistence malaria transmission such as population movement from high to low transmission settings. A cross-sectional community-based study was carried out to determine malaria prevalence and risk factors in Makenene, a small city in a forest-savannah which is a crossroads between different parts of the country where travellers usually stop-over day and night to rest. Using malaria diagnostic test (mRDTs from SD-BIOLINE) and microscopy (thin and thick blood smears), 406 participants from 237 households were tested for malaria infection. The prevalence of malaria was high irrespective of the detection method: mRDT (41.87%) or microscopy (38.42%). At household level, 46.41% of households had at least one case of malaria with an average of 1.41 infected individuals per household. Parasite density was also high with the majority of infected individuals (64.74%) bearing more than 500 parasites/μl. Only Plasmodium falciparum was found. The chances of being infected with malaria parasites was almost the same for all participants irrespective of the sleeping behavior, bednet usage, house type and environmental factors. The study supports high malaria transmission in the locality and the need for additional studies on vectors bionomics and transmission patterns.

Malaria Parasite Detection Using a Quantum-Convolutional Network

Malaria is a severe illness triggered by parasites that spreads via mosquito bites. In underdeveloped nations, malaria is one of the top causes of mortality, and it is mainly diagnosed through microscopy. Computer-assisted malaria diagnosis is difficult owing to the fine-grained differences throughout the presentation of some uninfected and infected groups. Therefore, in this study, we present a new idea based on the ensemble quantum-classical framework for malaria classification. The methods comprise three core steps: localization, segmentation, and classification. In the first core step, an improved FRCNN model is proposed for the localization of the infected malaria cells. Then, the RGB localized images were converted into YCbCr channels to normalize the image intensity values. Subsequently, the actual lesion region was segmented using a histogram-based color thresholding approach. The segmented images were employed for classification in two different ways. In the first method, a CNN model is developed by the selection of optimum layers after extensive experimentation, and the final computed feature vector is passed to the softmax layer for classification of the infection/non-infection of the microscopic malaria images. Second, a quantum-convolutional model is employed for informative feature extraction from microscopic malaria images, and the extracted feature vectors are supplied to the softmax layer for classification. Finally, classification results were analyzed from two different models and concluded that the quantum-convolutional model achieved maximum accuracy as compared to CNN. The proposed models attain a precision rate greater than 90%, thereby proving that these models performed better than the existing models.

A Rapid FRET Real-Time PCR Protocol for Simultaneous Quantitative Detection and Discrimination of Human Plasmodium Parasites.

Malaria is the most important parasitic disease worldwide, and accurate diagnosis and treatment without delay are essential for reducing morbidity and mortality, especially in P. falciparum malaria. Real-time PCR is highly sensitive and highly specific, therefore an excellent diagnostic tool for laboratory detection and species-specific diagnosis of malaria, especially in non-endemic regions where experience in microscopic malaria diagnostics is limited. In contrast to many other real-time PCR protocols, our new fluorescence resonance energy transfer-based real-time PCR (FRET-qPCR) allows the quantitative and species-specific detection of all human Plasmodium spp. in one run. Species identification is based on single nucleotide polymorphisms (SNPs) within the MalFL probe, detectable by melting curve analysis. A significant advantage of our FRET-qPCR is the short turn-around time of less than two hours, including DNA extraction, which qualifies it for routine diagnostics. Rapid and reliable species-specific malaria diagnosis is important, because treatment is species-dependent. Apart from first-line diagnosis, the quantitative results of our new FRET-qPCR can be helpful in therapy control, to detect early treatment failure. Graphic abstract.

Plasmodium falciparum Merozoite Surface Protein 2 Genetic Diversity and Multiplicity of Infection in Asymptomatic Malaria Cases in Lagos, Nigeria

Background: The burden of malaria due to Plasmodium falciparum is high in Nigeria. Continuous surveillance of the genetic diversity of malaria parasites can provide important information on transmission intensity in an area. Objective: This study investigated the genetic diversity in the highly polymorphic merozoite surface protein 2 (msp2) gene of P. falciparum in in asymptomatc malaria cases. Methods: A total of 59 P. falciparum-positive DNA samples collected from asymptomatic cases in Igbogbo-Bayekun, Lagos, were analyzed targeting block 3 of msp2 gene. Primers were specific for the two allelic families of msp2 block 3 (FC27 and 3D7). Results: Overall, the frequencies of 3D7 and FC27 alleles were 71.2% (42/59) and 67.8% (40/59) respectively. Twenty-three (39%) of the samples had polyinfections (3D7+FC27), while monoinfections with 3D7 and FC27 were observed in 19 (32%) and 17 (29%) samples respectively. Similar frequencies of 3D7 19/25(76%) and FC27 18/25(72%) were observed in samples with submicroscopic parasitaemia. Twenty-seven distinct msp2 genotypes were identified: 14 3D7 (range 175–480 bp) and 13 FC27 (range 125–500bp). Overall, there were more monoclonal infections 35(59.3%) than polyclonal infections 24 (40.7%). The overall mean multiplicity of infection (MOI) was 1.44 while the expected heterozygosity (He) was 0.51. The means of MOI were similar when compared on the basis of malaria status (microscopic or submicroscopic parasitemia) (P=0.166), gender (P=0.057) or age (P=0.866). Also, there was no association between polyclonal infection and submicroscopic parasitaemia (P=0.129). Conclusion: The genetic diversity of falciparum infections in the study area is high while moderate multiplicity of infection was observed. The genetic diversity and MOI of msp2 gene were similar in submicroscopic and microscopic malaria parasitaemia.

Prevalence of Infection and Malaria Parasite Density among Under Five Children: A Case Study of Dunukofia Rural Community in Anambra State, Nigeria

Aim: Malaria still remains an overwhelming cause of morbidity and mortality among children under five years of age, especially in sub-Saharan Africa. The study was carried out to evaluate malaria prevalence amongst children less than five years old. &#x0D; Study Design: A cross sectional study was carried out. The study adopted a retrospective descriptive survey using the hospital records and diagnostic cross sectional survey by examination of blood samples across three variables: gender, age group and mosquito net usage.&#x0D; Duration: The study was done in 2021 from the month of March to April in the rural community. &#x0D; Methodology: Parasitological diagnosis was with Plasmodium falciparum histidine-rich protein 2-based malaria Rapid Diagnostic Test (RDT) and microscopy of giemsa-stained blood smears. Demographic information was collected using questionnaire.&#x0D; Results: Three hundred (300) children aged less than five years malaria infection status was investigate, 174 (58.00% ) of them were females while 126 (42.00%. ) were males. Twenty one percent (21.00%) of the respondents are &lt;1 year, 23.33% (70) of them are between the ages of 2 to 3 years, while 55.67% (167) were 4 years and above. Current malaria prevalence was higher with microscopy (67.33%) than that of RDT (23.33%). Also, previous RDT results showed that there was a higher prevalence (73.56%) of malaria parasites in females than males (58.73%). The microscopy results showed that males had a higher prevalence (38.10%) of malaria parasites than females (12.64%). Overall gender result also revealed that males had a higher prevalence (96.83%) of malaria parasites than females (86.21%). There was a significant difference in the prevalence result with gender (P&lt;0.05). Females had higher parasite density (28.05±15.390) than males (23.22±19.171), there was no significant difference (P&gt;0.05). It further revealed that children from 4 years and above had higher intensity (29.68±17.357) while those of 1 year and below had the least (14.89±16.069). However, there was no significant difference in the malaria parasite among the age groups of patients (P&gt;0.05).&#x0D; Conclusion: Prevalence of malaria parasitaemia was still high in Dunukaofia, Anamba State, Nigeria despite various control measures and interventions put in place by WHO.

Co-infections and Comorbidities of Multiple Parasites and Hepatitis B Virus Infections in the Lowland Area of Western Ethiopia: Implications for Integrated Approaches.

BackgroundIn the current study area, the burden of morbidities associated with S. mansoni, soil-transmitted helminths (STHs), asymptomatic malaria, and hepatitis B virus (HBV) infections and co-infection has not been known for the last 20 years. This necessitated a systematic investigation of the status of these infections and their associated morbidities in the lowland areas of the Abbey and Didessa Valleys in Western Ethiopia.MethodsWe used a cross-sectional study design in three schistosomiasis endemic areas. Systematic random sampling and simple random sampling techniques were used to select households and one study participant from each household. Each selected and consented participants were give stool sample for S. mansoni and soil-transmitted helminths screening using duplicate kato-Katz technique; blood sample for screen of asymptomatic malaria using malaria rapid diagnostic test and microscopy and hepatitis B virus using hepatitis B surface antigen kit and anthropometric measurement to assess nutritional status and digital hemoglobin meter to measure hemoglobin and interviewed using structured questionnaire to assess factors associated with infections. A descriptive statistic to summarize the data and a chi-square test, Fisher’s exact test, and binary logistic regression models were used to see the associations.ResultsThe overall prevalence of studied infections was 74.5%. It was highest for Schistosoma mansoni (53.9%), followed by asymptomatic Plasmodium falciparum infection (23.6%). The prevalence of Schistosoma mansoni co-infection with asymptomatic malaria was 8.6%, Schistosoma mansoni and soil-transmitted helminths co-infection was 6.2%, and the seroprevalence of hepatitis B virus was 2.9%. About half (49.9%) of the study participants were undernourished and about a quarter (24.4%) were anemic. Age group, the younger age group and infection status, those with multiple infections were more anemic and commonly undernourished.ConclusionThere was a high prevalence of infections in the study area. Morbidities such as undernutrition and anemia were still prominent public health problems. There was a significant association between infection status and undernutrition and anemia.