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Scientific Reports Jul 2023Molecular detection methods have revealed higher sensitivity and specificity than conventional microscopy or rapid diagnostic tests for malaria diagnosis. In this study,...
Molecular detection methods have revealed higher sensitivity and specificity than conventional microscopy or rapid diagnostic tests for malaria diagnosis. In this study, we implemented, evaluated and validated according to the ISO 15,189 requirements, a multiplex real-time PCR assay to detect and identify the five human malaria parasites. DNA samples were extracted from whole blood or dried blood spots drawn from patients. Based on the External Quality Assessment (whole blood), this method shows 100% sensitivity and specificity. This PCR detected P. vivax up to 0.25 p/µl, P. falciparum and P. knowlesi up to 0.5 p/µl, P. ovale up to 1 p/µl and P. malariae up to 5 p/µl of blood. From blood spots (extraction from four punches), it detected P. vivax at 5 p/µl, P. falciparum, P. ovale and P. knowlesi at 20 p/µl and P. malariae at 125 p/µl. In conclusion, this quantitative PCR shows excellent performance, is easy to use and DNA saver. It is especially useful to actively screen large population groups and identify the five human malaria parasites in a context of low malaria transmission.
Topics: Humans; Real-Time Polymerase Chain Reaction; Plasmodium; Malaria; Malaria, Vivax; Malaria, Falciparum; Sensitivity and Specificity; Plasmodium vivax; Plasmodium falciparum
PubMed: 37452123
DOI: 10.1038/s41598-023-38621-9 -
PloS One 2023The double burden of malaria and helminthiasis in children poses an obvious public health challenge, particularly in terms of anemia morbidity. While both diseases...
BACKGROUND
The double burden of malaria and helminthiasis in children poses an obvious public health challenge, particularly in terms of anemia morbidity. While both diseases frequently geographically overlap, most studies focus on mono-infection and general prevalence surveys without molecular analysis. The current study investigated the epidemiological determinants of malaria, schistosomiasis, and geohelminthiasis transmission among children in the North Region of Cameroon.
METHODOLOGY
School and pre-school children aged 3-15 year-of-age were enrolled from three communities in March 2021 using a community cross-sectional design. Capillary-blood samples were obtained, and each was examined for malaria parasites using rapid-diagnostic-test (RDT), microscopy, and PCR while hemoglobin level was measured using a hemoglobinometer. Stool samples were analyzed for Schistosoma mansoni, S. guineensis, and soil-transmitted-helminthiasis (STH) infections using the Kato Katz method, and urine samples were assessed for the presence of S. haematobium eggs (including hybrids) using the standard urine filtration technique.
RESULT
A malaria prevalence of 56% (277/495) was recorded by PCR as opposed to 31.5% (156/495) by microscopy and 37.8% (186/495) by RDT. Similarly, schistosomiasis was observed at prevalence levels of up to 13.3% (66/495) overall [S. haematobium (8.7%); S. mansoni (3.8%); mixed Sh/Sm (0.6%); mixed Sh/Sm/Sg (0.2%). Both infections were higher in males and the 3-9 year-of-age groups. A high frequency of PCR reported P. falciparum mono-infection of 81.9% (227/277) and mixed P. falciparum/P. malariae infection of 17.3% (48/277) was observed. Malaria-helminths co-infections were observed at 13.1% (65/495) with marked variation between P. falciparum/S. haematobium (50.8%, 33/65); P. falciparum/S. mansoni (16.9%, 11/65) and P. falciparum/Ascaris (9.2%, 6/65) (χ2 = 17.5, p = 0.00003). Anemia prevalence was 32.9% (163/495), categorically associated with P. falciparum (45.8%, 104/227), Pf/Sh (11.5%, 26/227), and Pf/Sm (3.9%, 9/227) polyparasitism.
CONCLUSION
Polyparasitism with malaria and helminth infections is common in school-aged children despite periodic long-lasting insecticide-treated nets (LLINs) distribution and regular school-based praziquantel (for schistosomiasis) and albendazole (for STH) campaigns. Co-existence of Plasmodium parasites and helminths infections notably Schistosoma species among children may concurrently lead to an increase in Plasmodium infection with an enhanced risk of anemia, highlighting the necessity of an integrated approach for disease control interventions.
Topics: Male; Animals; Humans; Child, Preschool; Child; Adolescent; Cross-Sectional Studies; Cameroon; Seasons; Schistosomiasis; Helminthiasis; Malaria; Malaria, Falciparum; Schistosoma mansoni; Anemia; Prevalence; Feces; Soil
PubMed: 37523402
DOI: 10.1371/journal.pone.0288560 -
Malaria Journal Sep 2023The routine surveillance of asymptomatic malaria using nucleic acid-based amplification tests is essential in obtaining reliable data that would inform malaria policy...
BACKGROUND
The routine surveillance of asymptomatic malaria using nucleic acid-based amplification tests is essential in obtaining reliable data that would inform malaria policy formulation and the implementation of appropriate control measures.
METHODS
In this study, the prevalence rate and the dynamics of Plasmodium species among asymptomatic children (n = 1697) under 5 years from 30 communities within the Hohoe municipality in Ghana were determined.
RESULTS AND DISCUSSION
The observed prevalence of Plasmodium parasite infection by polymerase chain reaction (PCR) was 33.6% (571/1697), which was significantly higher compared to that obtained by microscopy [26.6% (451/1697)] (P < 0.0001). Based on species-specific analysis by nested PCR, Plasmodium falciparum infection [33.6% (570/1697)] was dominant, with Plasmodium malariae, Plasmodium ovale and Plasmodium vivax infections accounting for 0.1% (1/1697), 0.0% (0/1697), and 0.0% (0/1697), respectively. The prevalence of P. falciparum infection among the 30 communities ranged from 0.0 to 82.5%. Following artesunate-amodiaquine (AS + AQ, 25 mg/kg) treatment of a sub-population of the participants (n = 184), there was a substantial reduction in Plasmodium parasite prevalence by 100% and 79.2% on day 7 based on microscopy and nested PCR analysis, respectively. However, there was an increase in parasite prevalence from day 14 to day 42, with a subsequent decline on day 70 by both microscopy and nested PCR. For parasite clearance rate analysis, we found a significant proportion of the participants harbouring residual Plasmodium parasites or parasite genomic DNA on day 1 [65.0% (13/20)], day 2 [65.0% (13/20)] and day 3 [60.0% (12/20)] after initiating treatment. Of note, gametocyte carriage among participants was low before and after treatment.
CONCLUSION
Taken together, the results indicate that a significant number of individuals could harbour residual Plasmodium parasites or parasite genomic DNA after treatment. The study demonstrates the importance of routine surveillance of asymptomatic malaria using sensitive nucleic acid-based amplification techniques.
Topics: Child; Humans; Ghana; Malaria; Artemisinins; Malaria, Falciparum; Plasmodium malariae; Nucleic Acids
PubMed: 37710288
DOI: 10.1186/s12936-023-04712-1 -
Tropical Medicine and Infectious Disease Oct 2023() causes zoonotic malaria and is known as the "fifth human malaria parasite". malaria is an emerging threat because infections are increasing and can be fatal. While... (Review)
Review
() causes zoonotic malaria and is known as the "fifth human malaria parasite". malaria is an emerging threat because infections are increasing and can be fatal. While most infections are in Southeast Asia (SEA), especially Malaysia, travelers frequently visit this region and can present with malaria around the world. So, clinicians need to know (1) patients who present with fever after recent travel to SEA might be infected with and (2) is often misdiagnosed as (which typically causes less severe malaria). Here we review the history, pathophysiology, clinical features, diagnosis, and treatment of malaria. Severe disease is most common in adults. Signs and symptoms can include fever, abdominal pain, jaundice, acute kidney injury, acute respiratory distress syndrome, hyponatremia, hyperparasitemia, and thrombocytopenia. Dengue is one of the diseases to be considered in the differential. Regarding pathophysiologic mechanisms, when parasites invade mature red blood cells (RBCs, i.e., normocytes) and reticulocytes, changes in the red blood cell (RBC) surface can result in life-threatening cytoadherence, sequestration, and reduced RBC deformability. Since molecular mechanisms involving the erythrocytic stage are responsible for onset of severe disease and lethal outcomes, it is biologically plausible that manual exchange transfusion (ET) or automated RBC exchange (RBCX) could be highly beneficial by replacing "sticky" parasitized RBCs with uninfected, deformable, healthy donor RBCs. Here we suggest use of special -resistant donor RBCs to optimize adjunctive manual ET/RBCX for malaria. "Therapeutically-rational exchange transfusion" (T-REX) is proposed in which -resistant RBCs are transfused (instead of disease-promoting RBCs). Because expression of the Duffy antigen on the surface of human RBCs is essential for parasite invasion, T-REX of Duffy-negative RBCs-also known as Fy(a-b-) RBCs-could replace the majority of the patient's circulating normocytes with invasion-resistant RBCs (in a single procedure lasting about 2 h). When sequestered or non-sequestered iRBCs rupture-in a 24 h asexual life cycle-the released merozoites cannot invade Fy(a-b-) RBCs. When Fy(a-b-) RBC units are scarce (e.g., in Malaysia), clinicians can consider the risks and benefits of transfusing plausibly -resistant RBCs, such as glucose-6-phosphate dehydrogenase deficient (G6PDd) RBCs and Southeast Asian ovalocytes (SAO). Patients typically require a very short recovery time (<1 h) after the procedure. Fy(a-b-) RBCs should have a normal lifespan, while SAO and G6PDd RBCs may have mildly reduced half-lives. Because SAO and G6PDd RBCs come from screened blood donors who are healthy and not anemic, these RBCs have a low-risk for hemolysis and do not need to be removed after the patient recovers from malaria. T-REX could be especially useful if (1) antimalarial medications are not readily available, (2) patients are likely to progress to severe disease, or (3) drug-resistant strains emerge. In conclusion, T-REX is a proposed optimization of manual ET/RBCX that has not yet been utilized but can be considered by physicians to treat malaria patients.
PubMed: 37888606
DOI: 10.3390/tropicalmed8100478 -
Malaria Journal May 2024Malaria elimination in Senegal requires accurate diagnosis of all Plasmodium species. Plasmodium falciparum is the most prevalent species in Senegal, although Plasmodium...
BACKGROUND
Malaria elimination in Senegal requires accurate diagnosis of all Plasmodium species. Plasmodium falciparum is the most prevalent species in Senegal, although Plasmodium malariae, Plasmodium ovale, and recently Plasmodium vivax have also been reported. Nonetheless, most malaria control tools, such as Histidine Rich Protein 2 rapid diagnosis test (PfHRP2-RDT,) can only diagnose P. falciparum. Thus, PfHRP2-RDT misses non-falciparum species and P. falciparum infections that fall below the limit of detection. These limitations can be addressed using highly sensitive Next Generation Sequencing (NGS). This study assesses the burden of the four different Plasmodium species in western and eastern regions of Senegal using targeted PCR amplicon sequencing.
METHODS
Three thousand samples from symptomatic and asymptomatic individuals in 2021 from three sites in Senegal (Sessene, Diourbel region; Parcelles Assainies, Kaolack region; Gabou, Tambacounda region) were collected. All samples were tested using PfHRP2-RDT and photoinduced electron transfer polymerase chain reaction (PET-PCR), which detects all Plasmodium species. Targeted sequencing of the nuclear 18S rRNA and the mitochondrial cytochrome B genes was performed on PET-PCR positive samples.
RESULTS
Malaria prevalence by PfHRP2-RDT showed 9.4% (94/1000) and 0.2% (2/1000) in Diourbel (DBL) and Kaolack (KL), respectively. In Tambacounda (TAM) patients who had malaria symptoms and had a negative PfHRP2-RDT were enrolled. The PET-PCR had a positivity rate of 23.5% (295/1255) overall. The PET-PCR positivity rate was 37.6%, 12.3%, and 22.8% in Diourbel, Kaolack, and Tambacounda, respectively. Successful sequencing of 121/295 positive samples detected P. falciparum (93%), P. vivax (2.6%), P. malariae (4.4%), and P. ovale wallikeri (0.9%). Plasmodium vivax was co-identified with P. falciparum in thirteen samples. Sequencing also detected two PfHRP2-RDT-negative mono-infections of P. vivax in Tambacounda and Kaolack.
CONCLUSION
The findings demonstrate the circulation of P. vivax in western and eastern Senegal, highlighting the need for improved malaria control strategies and accurate diagnostic tools to better understand the prevalence of non-falciparum species countrywide.
Topics: Senegal; Humans; Adolescent; Adult; Young Adult; Child; Middle Aged; Male; Female; Plasmodium vivax; Child, Preschool; Malaria, Vivax; Prevalence; Aged; Infant; Polymerase Chain Reaction; Plasmodium ovale
PubMed: 38750583
DOI: 10.1186/s12936-024-04932-z -
Tropical Medicine and Infectious Disease Sep 2023Up-to-date knowledge of key epidemiological aspects of each species is necessary for making informed decisions on targeted interventions and control strategies to...
Up-to-date knowledge of key epidemiological aspects of each species is necessary for making informed decisions on targeted interventions and control strategies to eliminate each of them. This study aims to describe the epidemiology of plasmodial species in Mali, where malaria is hyperendemic and seasonal. Data reports collected during high-transmission season over six consecutive years were analyzed to summarize malaria epidemiology. Malaria species and density were from blood smear microscopy. Data from 6870 symptomatic and 1740 asymptomatic participants were analyzed. The median age of participants was 12 years, and the sex ratio (male/female) was 0.81. Malaria prevalence from all species was 65.20% (95% CI: 60.10-69.89%) and 22.41% (CI: 16.60-28.79%) for passive and active screening, respectively. was the most prevalent species encountered in active and passive screening (59.33%, 19.31%). This prevalence was followed by (1.50%, 1.15%) and (0.32%, 0.06%). Regarding frequency, was more frequent in symptomatic individuals (96.77% vs. 93.24%, = 0.014). In contrast, was more frequent in asymptomatic individuals (5.64% vs. 2.45%, < 0.001). remained the least frequent species (less than 1%), and no was detected. The most frequent coinfections were and (0.56%). Children aged 5-9 presented the highest frequency of infections (41.91%). Non- species were primarily detected in adolescents (10-14 years) with frequencies above 50%. Only infections had parasitemias greater than 100,000 parasites per µL of blood. gametocytes were found with variable prevalence across age groups. Our data highlight that represented the first burden, but other non- species were also important. Increasing attention to and is essential if malaria elimination is to be achieved.
PubMed: 37755899
DOI: 10.3390/tropicalmed8090438 -
Health Science Reports Oct 2023Malaria is a parasitic infection primarily caused by four main species of the genus , that is, , , , and . It is transmitted through the bite of the female mosquito. It...
BACKGROUND
Malaria is a parasitic infection primarily caused by four main species of the genus , that is, , , , and . It is transmitted through the bite of the female mosquito. It holds the status of one of the leading causes of death in the developing world. Malaria is endemic to Pakistan, and the country experienced the worst floods in its history from April to October 2022. The stagnant flood water served as a breeding ground for mosquitoes, culminating in an alarming spike in malaria cases. According to the World Health Organization (WHO), the number of cases reported till August 2022 was more than in the whole year of 2021. There was more than a twofold rise in cumulative cases in 62 high-burden Pakistani Districts in August 2022 as compared to August 2021.
AIMS
This commentary aims to bring this emerging issue to notice and highlight the most effective probable measures to help eliminate and prevent the hazards the current outbreak poses.
RESULTS
Rapid planning and execution are needed to ensure the most efficient and rapid elimination of malaria. To educate the general public, the national government must start public awareness efforts in electronic, print, and social media and deploy solar-powered mobile healthcare units to far-flung areas. Prophylactic and postexposure treatments should be planned because larvicidal preventive measures are less practical in flood-affected vicinities.
CONCLUSION
The most effective preventive strategy is drug prophylaxis, followed by insecticide-treated nets, indoor residual spraying, and untreated nets. Scientists should intensify their investigations for effective medications to alleviate the malaria burden in Pakistan.
PubMed: 37822844
DOI: 10.1002/hsr2.1620 -
Malaria Journal Oct 2023Since 2018, no indigenous human malaria cases has been reported in Malaysia. However, during the recent COVID-19 pandemic the World Health Organization is concerned that...
BACKGROUND
Since 2018, no indigenous human malaria cases has been reported in Malaysia. However, during the recent COVID-19 pandemic the World Health Organization is concerned that the pandemic might erode the success of malaria control as there are reports of increase malaria cases in resource limited countries. Little is known how the COVID-19 pandemic has impacted malaria in middle-income countries like Malaysia. Here the public health response to a Plasmodium malariae outbreak occurred in a village in Sabah state, Malaysia, during a COVID-19 movement control order is reported.
METHODS
An outbreak was declared following the detection of P. malariae in July 2020 and active case detection for malaria was performed by collecting blood samples from residents residing within 2 km radius of Moyog village. Vector prevalence and the efficacy of residual insecticides were determined. Health awareness programmes were implemented to prevent future outbreaks. A survey was conducted among villagers to understand risk behaviour and beliefs concerning malaria.
RESULTS
A total of 5254 blood samples collected from 19 villages. Among them, 19 P. malariae cases were identified, including the index case, which originated from a man who returned from Indonesia. His return from Indonesia and healthcare facilities visit coincided with the movement control order during COVID-19 pandemic when the healthcare facilities stretched its capacity and only serious cases were given priority. Despite the index case being a returnee from a malaria endemic area presenting with mild fever, no malaria test was performed at local healthcare facilities. All cases were symptomatic and uncomplicated except for a pregnant woman with severe malaria. There were no deaths; all patients recovered following treatment with artemether-lumefantrine combination therapy. Anopheles balabacensis and Anopheles barbirostris were detected in ponds, puddles and riverbeds. The survey revealed that fishing and hunting during night, and self-treatment for mild symptoms contributed to the outbreak. Despite the index case being a returnee from a malaria-endemic area presenting with mild fever, no malaria test was performed at local healthcare facilities.
CONCLUSION
The outbreak occurred during a COVID-19 movement control order, which strained healthcare facilities, prioritizing only serious cases. Healthcare workers need to be more aware of the risk of malaria from individuals who return from malaria endemic areas. To achieve malaria elimination and prevention of disease reintroduction, new strategies that include multisectoral agencies and active community participation are essential for a more sustainable malaria control programme.
Topics: Male; Animals; Female; Humans; Malaysia; Plasmodium malariae; Antimalarials; Public Health; Pandemics; Mosquito Vectors; Plasmodium knowlesi; Artemether; Artemether, Lumefantrine Drug Combination; COVID-19; Malaria; Disease Outbreaks; Anopheles
PubMed: 37789320
DOI: 10.1186/s12936-023-04693-1 -
Malaria Journal Apr 2024While Plasmodium falciparum and Plasmodium vivax cause the majority of malaria cases and deaths, infection by Plasmodium malariae and other Plasmodium species also...
BACKGROUND
While Plasmodium falciparum and Plasmodium vivax cause the majority of malaria cases and deaths, infection by Plasmodium malariae and other Plasmodium species also causes morbidity and mortality. Current understanding of these infections is limited in part by existing point-of-care diagnostics that fail to differentiate them and have poor sensitivity for low-density infections. Accurate diagnosis currently requires molecular assays performed in well-resourced laboratories. This report describes the development of a P. malariae diagnostic assay that uses rapid, isothermal recombinase polymerase amplification (RPA) and lateral-flow-strip detection.
METHODS
Multiple combinations of custom RPA primers and probes were designed using publicly available P. malariae genomic sequences, and by modifying published primer sets. Based on manufacturer RPA reaction conditions (TwistDx nfo kit), an isothermal assay was optimized targeting the multicopy P. malariae 18S rRNA gene with 39 °C incubation and 30-min run time. RPA product was visualized using lateral strips (FAM-labeled, biotinylated amplicon detected by a sandwich immunoassay, visualized using gold nanoparticles). Analytical sensitivity was evaluated using 18S rRNA plasmid DNA, and clinical sensitivity determined using qPCR-confirmed samples collected from Tanzania, Ethiopia, and the Democratic Republic of the Congo.
RESULTS
Using 18S rRNA plasmid DNA, the assay demonstrates a detection limit of 10 copies/µL (~ 1.7 genome equivalents) and 100% analytical specificity. Testing in field samples showed 95% clinical sensitivity and 88% specificity compared to qPCR. Total assay time was less than 40 min.
CONCLUSION
Combined with simplified DNA extraction methods, the assay has potential for future field-deployable, point-of-care use to detect P. malariae infection, which remains largely undiagnosed but a neglected cause of chronic malaria. The assay provides a rapid, simple readout on a lateral flow strip without the need for expensive laboratory equipment.
Topics: Gold; Metal Nanoparticles; RNA, Ribosomal, 18S; Biological Assay; DNA
PubMed: 38609964
DOI: 10.1186/s12936-024-04928-9 -
MedRxiv : the Preprint Server For... May 2024The emergence of the zoonotic monkey parasite as the dominant cause of malaria in Malaysia has disrupted current national WHO elimination goals. Malaysia has free...
BACKGROUND
The emergence of the zoonotic monkey parasite as the dominant cause of malaria in Malaysia has disrupted current national WHO elimination goals. Malaysia has free universal access to malaria care; however, out-of-pocket costs are unknown. This study estimated household costs of illness attributable to malaria due to against other non-zoonotic species infections in Sabah, Malaysia.
METHODOLOGY/PRINCIPAL FINDINGS
Household costs were estimated from patient-level surveys collected from four hospitals between 2013 and 2016. Direct costs including medical and associated travel costs, and indirect costs due to lost productivity were included. One hundred and fifty-two malaria cases were enrolled: (n=108), (n=22), (n=16), and (n=6). Costs were inflated to 2022 Malaysian Ringgits and reported in United States dollars (US$). Across all cases, the mean total costs were US$138 (SD=108), with productivity losses accounting for 58% of costs (US$80; SD=73). had the highest mean total household cost at US$210, followed by (US$127), (US$126), and (US$105). Most patients (80%) experienced direct health costs above 10% of monthly income, with 58 (38%) patients experiencing health spending over 25% of monthly income, consistent with catastrophic health expenditure.
CONCLUSIONS/SIGNIFICANCE
Despite Malaysia's free health-system care for malaria, patients and families face other related medical, travel, and indirect costs. Household out-of-pocket costs were driven by productivity losses; primarily attributed to infections in working-aged males in rural agricultural-based occupations. Costs for were comparable to and lower than The higher costs related to direct health facility costs for repeat monitoring visits given the liver-stage treatment required.
AUTHOR SUMMARY
Knowlesi malaria is due to infection with a parasite transmitted by mosquitos from monkeys to humans. Most people who are infected work or live near the forest. It is now the major type of malaria affecting humans in Malaysia. The recent increase of knowlesi malaria cases in humans has impacted individuals, families, and health systems in Southeast Asia. Although the region has made substantial progress towards eliminating human-only malaria species, knowlesi malaria threatens elimination targets as traditional control measures do not address the parasite reservoir in monkeys. The economic burden of illness due to knowlesi malaria has not previously been estimated or subsequently compared with other malaria species. We collected data on the cost of illness to households in Sabah, Malaysia, to estimate their related total economic burden. Medical costs and time off work and usual activities were substantial in patients with the four species of malaria diagnosed during the time of this study. This research highlights the financial burden which households face when seeking care for malaria in Malaysia, despite the free treatment provided by the government.
PubMed: 38746350
DOI: 10.1101/2024.05.02.24306734