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The American Journal of Tropical... May 2024India is a major contributor to the global burden of malaria, especially Plasmodium vivax infection. Understanding the spatiotemporal trends of malaria across India over...
India is a major contributor to the global burden of malaria, especially Plasmodium vivax infection. Understanding the spatiotemporal trends of malaria across India over the last two decades may assist in targeted intervention. The population-normalized spatiotemporal trends of malaria epidemiology in India from 2007 to 2022 were analyzed using a geographic information system with the publicly available "malaria situation" report of the National Vector Borne Disease Control Program (NVBDCP). The NVBDCP data showed malaria cases to have steeply declined from 1.17 million in 2015 to 0.18 million cases in 2022; this is 10.1 and 18.7 fold lower than the WHO's estimate of 11.93 million and 3.38 million cases in 2015 and 2022, respectively. From 2007 to 2022, Mizoram, Meghalaya, Tripura, Odisha, Chhattisgarh, and Jharkhand consistently reported high caseloads of Plasmodium falciparum. In the same period, the P. vivax caseload was high in Arunachal Pradesh, Mizoram, Nagaland, Jharkhand, Odisha, Chhattisgarh, Goa, Daman and Diu, Dadra and Nagar Haveli, and Andaman and Nicobar Islands. The distribution of forest cover, annual rainfall, and proportion of the Scheduled Tribe population (the most underprivileged in Indian society) spatially correlated with malaria cases and deaths. Mizoram is the only state where cases were higher in 2022 than in 2007. Overall, India has made tremendous progress in controlling malaria and malaria-related deaths in the last decade. The decline could be attributed to the effective vector and parasite control strategies implemented across the country.
PubMed: 38772359
DOI: 10.4269/ajtmh.23-0688 -
PLOS Global Public Health 2024Sensitive and accurate malaria diagnosis is required for case management to accelerate control efforts. Diagnosis is particularly challenging where multiple Plasmodium...
Sensitive and accurate malaria diagnosis is required for case management to accelerate control efforts. Diagnosis is particularly challenging where multiple Plasmodium species are endemic, and where P. falciparum hrp2/3 deletions are frequent. The Noul miLab is a fully automated portable digital microscope that prepares a blood film from a droplet of blood, followed by staining and detection of parasites by an algorithm. Infected red blood cells are displayed on the screen of the instrument. Time-to-result is approximately 20 minutes, with less than two minutes hands-on time. We evaluated the miLab among 659 suspected malaria patients in Gondar, Ethiopia, where P. falciparum and P. vivax are endemic, and the frequency of hrp2/3 deletions is high, and 991 patients in Ghana, where P. falciparum transmission is intense. Across both countries combined, the sensitivity of the miLab for P. falciparum was 94.3% at densities >200 parasites/μL by qPCR, and 83% at densities >20 parasites/μL. The miLab was more sensitive than local microscopy, and comparable to RDT. In Ethiopia, the miLab diagnosed 51/52 (98.1%) of P. falciparum infections with hrp2 deletion at densities >20 parasites/μL. Specificity of the miLab was 94.0%. For P. vivax diagnosis in Ethiopia, the sensitivity of the miLab was 97.0% at densities >200 parasites/μL (RDT: 76.8%, microscopy: 67.0%), 93.9% at densities >20 parasites/μL, and specificity was 97.6%. In Ethiopia, where P. falciparum and P. vivax were frequent, the miLab assigned the wrong species to 15/195 mono-infections at densities >20 parasites/μL by qPCR, and identified only 5/18 mixed-species infections correctly. In conclusion, the miLab was more sensitive than microscopy and thus is a valuable addition to the toolkit for malaria diagnosis, particularly for areas with high frequencies of hrp2/3 deletions.
PubMed: 38768243
DOI: 10.1371/journal.pgph.0003091 -
SAGE Open Medicine 2024In the Eastern Mediterranean region, Afghanistan ranks third for the world's highest burden of malaria. The vast majority (95%) of malaria cases in Afghanistan are...
BACKGROUND
In the Eastern Mediterranean region, Afghanistan ranks third for the world's highest burden of malaria. The vast majority (95%) of malaria cases in Afghanistan are attributed to and 5% to . Most cases occur in low-altitude regions, especially in the eastern province of Nangarhar, where agriculture and farming are predominant. To better understand the public sentiment toward malaria, this study aimed to understand the knowledge, attitude, and practice of patients toward malaria who visited public and private hospitals of Nangarhar province.
METHODS
A cross-sectional descriptive study was conducted on Nangarhar residents who visited the adult Outpatient departments of eight local public and private health facilities. Data collection took place from 1st August 2022 to 15th September 2022.
RESULTS
Of 700 participants, 37.9% ( = 265) identified as male and 62.1% ( = 435) identified as female. The majority of participants (84.6 %) were within the (18-40) age range, followed by 12.7% in the (41-60) age range, and 2.7% were aged 61 years or older. Moreover, 99.7% ( = 698) of the participants had heard of malaria. The main sources of information about malaria were family members (31.3%, = 219), television (32.6%, = 228), Internet (12.6%, = 88), school (11.3%, = 79), and health facilities (31.4%, = 220). Most respondents correctly identified mosquito bites as the primary mode of malaria transmission (72.6%, = 508). Others suggested that transmission could occur by close contact with a malaria patient (14.0%, = 98) and drinking contaminated water (17.3%, = 121). The majority of participants (70.6%) agreed that malaria is a serious and life-threatening disease. A significant number of participants (96.6%) reported owning an insecticide-treated mosquito net at home, and 87.0% reported using the net.
CONCLUSION
Overall, participants reported good knowledge, attitude, and practice toward malaria. This may be linked to the awareness campaigns and preventive programs in Nangarhar province that have contributed to participant's willingness to prevent malaria and treat themselves if they get infected. Public health campaigns are difficult in Afghanistan with weak governance and conflict, and thus, populations may find themselves at risk if health promotion activities are stopped.
PubMed: 38764536
DOI: 10.1177/20503121241251758 -
Communications Medicine May 2024Five years after successful malaria elimination, Aneityum Island in Vanuatu experienced an outbreak of Plasmodium vivax of unknown origin in 2002. Epidemiological...
BACKGROUND
Five years after successful malaria elimination, Aneityum Island in Vanuatu experienced an outbreak of Plasmodium vivax of unknown origin in 2002. Epidemiological investigations revealed several potential sources of P. vivax. We aimed to identify the genetic origin of P. vivax responsible for the resurgence.
METHODS
Five P. vivax microsatellite markers were genotyped using DNA extracted from archived blood samples. A total of 69 samples from four P. vivax populations was included: 29 from the outbreak in 2002, seven from Aneityum in 1999 and 2000, 18 from visitors to Aneityum in 2000, and 15 from nearby Tanna Island in 2002. A neighbour-joining phylogenetic tree was constructed to elucidate the relationships among P. vivax isolates. STRUCTURE and principal component analysis were used to assess patterns of genetic structure.
RESULTS
Here we show distinct genetic origins of P. vivax during the outbreak on Aneityum. While the origin of most P. vivax lineages found during the outbreak remains unidentified, limited genetic diversity among these lineages is consistent with a rapid expansion from a recent common ancestor. Contemporaneous P. vivax from neighboring Tanna and potential relapse of P. vivax acquired from other islands in 1999 and 2000 are also identified as minor contributors to the outbreak.
CONCLUSIONS
Multiple reintroductions of P. vivax after elimination highlight the high receptivity and vulnerability to malaria resurgence in island settings of Vanuatu, despite robust surveillance and high community compliance to control measures.
PubMed: 38762604
DOI: 10.1038/s43856-024-00524-9 -
Indian Journal of Medical Microbiology 2024Genetically diverse parasites enhances resistance against antimalarials, vaccines and host immune responses. The present study was designed to evaluate the role played...
PURPOSE
Genetically diverse parasites enhances resistance against antimalarials, vaccines and host immune responses. The present study was designed to evaluate the role played by Plasmodium falciparum genetic diversity in predicting the real world malarial population.
METHODS
Initially, the incidence pattern of all four northern Indian malarial species was examined using 18S rRNA gene and performed principal component analysis (PCA) based on frequencies of Plasmodium species. Consequently, genetic variance of Plasmodium falciparum histidine-rich protein-2 (Pfhrp2) gene among different malarial populations were compared using phylogenetic analysis. Multi-dimensional scaling was performed to assess genetic similarities and distances among studied populations.
RESULTS
Of total 2168 patients screened, 561 patients with fever of unknown origin were included. 18S rRNA and Pfhrp2 genes were amplified in 78 and 45 samples, respectively. Among them 13.9%(78/561) patients had Plasmodium infection. Infections by P. falciparum, P. vivax and mixed infections were diagnosed among 47(60.2%) and 28(35.9%) and 3(3.8%) patients, respectively. We found eight types of Pfhrp2 amino acid sequence repeats among northern Indian population. The PCA findings were in line with genetic diversity and phylogenetic data. Temporal analysis showed the proportion of total diversity present in total subpopulation (ΔS/ΔT) was maximum for P. falciparum.
CONCLUSIONS
Higher incidence of Pfhrp2 sequence variation through genetic recombination among multiple strains during sexual reproduction is potentially correlated with high transmission activity. This sequence variation might alter RDT detection sensitivities for different parasites by modulating the structure and frequency of antigenic epitopes.
Topics: Humans; Protozoan Proteins; Plasmodium falciparum; Antigens, Protozoan; Genetic Variation; Malaria, Falciparum; India; Phylogeny; RNA, Ribosomal, 18S; Male; Female; Adult; Adolescent; Child; Young Adult; Child, Preschool; Middle Aged
PubMed: 38761865
DOI: 10.1016/j.ijmmb.2024.100616 -
Infection, Genetics and Evolution :... Aug 2024Plasmodium vivax Merozoite Surface Protein 8 (PvMSP8) is a promising candidate target for the development of multi-component vaccines. Therefore, determining the genetic...
Plasmodium vivax Merozoite Surface Protein 8 (PvMSP8) is a promising candidate target for the development of multi-component vaccines. Therefore, determining the genetic variation pattern of Pvmsp8 is essential in providing a reference for the rational design of the P. vivax malaria vaccines. This study delves into the genetic characteristics of the Pvmsp8 gene, specifically focusing on samples from the China-Myanmar border (CMB) region, and contrasts these findings with broader global patterns. The study uncovers that Pvmsp8 exhibits a notable level of conservation across different populations, with limited polymorphisms and relatively low nucleotide diversity (0.00023-0.00120). This conservation contrasts starkly with the high polymorphisms found in other P. vivax antigens such as Pvmsp1. A total of 25 haplotypes and 14 amino acid mutation sites were identified in the global populations, and all mutation sites were confined to non-functional regions. The study also notes that most CMB Pvmsp8 haplotypes are shared among Burmese, Cambodian, Thai, and Vietnamese populations, indicating less geographical variance, but differ notably from those found in Pacific island regions or the Panama. The findings underscore the importance of considering regional genetic diversity in P. vivax when developing targeted malaria vaccines. Non departure from neutral evolution were found by Tajima's D test, however, statistically significant differences were observed between the kn/ks rates. The study's findings are crucial in understanding the evolution and population structure of the Pvmsp8 gene, particularly during regional malaria elimination efforts. The highly conserved nature of Pvmsp8, combined with the lack of mutations in its functional domain, presents it as a promising candidate for developing a broad and effective P. vivax vaccine. This research thus lays a foundation for the rational development of multivalent malaria vaccines targeting this genetically stable antigen.
Topics: Plasmodium vivax; Selection, Genetic; Protozoan Proteins; Haplotypes; Humans; Genetic Variation; Malaria, Vivax; Mutation; Phylogeny; Antigens, Protozoan
PubMed: 38759940
DOI: 10.1016/j.meegid.2024.105605 -
Malaria Journal May 2024Malaria is a major public health concern in Ethiopia, where more than half of the population lives in malaria risk areas. While several studies have been conducted in...
BACKGROUND
Malaria is a major public health concern in Ethiopia, where more than half of the population lives in malaria risk areas. While several studies have been conducted in different eco-epidemiological settings in Ethiopia, there is a notable scarcity of data on the prevalence of malaria in the Gindabarat district. Therefore, this study aimed to analyse 10-year trend of malaria prevalence in Gindabarat district, West Shawa Zone of Oromia, Western Ethiopia.
METHODS
A retrospective laboratory record review was conducted at Gindabarat General Hospital and Gindabarat District Health Office from September 2011 to August 2020. The retrieved data included the date of examination, age, sex and laboratory results of the blood smears, including the Plasmodium species identified. Data were summarized and presented in the form of tables, figures, and frequencies to present the results. The data were analysed using SPSS (version 25.0) and Microsoft Excel.
RESULTS
Over the course of 10 years, a total of 11,478 blood smears were examined in the public health facilities in the district. Of the total blood smears examined, 1372 (11.95%) were microscopically confirmed malaria. Plasmodium falciparum, Plasmodium vivax and mixed infections (P. falciparum and P. vivax) accounted for 70.77%, 20.55% and 8.67% of the cases, respectively. Malaria prevalence was significantly higher among individuals aged ≥ 15 years (12.60%, x = 13.6, df = 2, p = 0.001) and males (14.21%, x = 59.7, df = 1, p = 0.001). The highest number of malaria cases was recorded from September to November.
CONCLUSION
Malaria remains a public health problem in the district. P. falciparum was the most predominant parasite species in the area. Malaria prevalence was significantly higher among individuals aged ≥ 15 years and males. There was a remarkable fluctuation in the number of malaria cases in different months and years. In the study area malaria cases peaked in 2015 and 2017 then decreasing from 2017 to 2019, with sharp increase in 2020. Moreover, this study showed malaria cases were reported in all seasons and months, but the highest was observed from September to November. Strengthening malaria control activities is essential to further reduce the burden of malaria and pave the way for the anticipated elimination.
Topics: Ethiopia; Prevalence; Male; Humans; Female; Retrospective Studies; Adolescent; Adult; Young Adult; Child; Child, Preschool; Malaria, Vivax; Middle Aged; Infant; Malaria, Falciparum; Plasmodium vivax; Plasmodium falciparum; Aged; Infant, Newborn; Aged, 80 and over
PubMed: 38755638
DOI: 10.1186/s12936-024-04975-2 -
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 -
Trends in Parasitology May 2024Plasmodium vivax contributes significantly to global malaria morbidity. Key advances include the discovery of pathways facilitating invasion by P. vivax merozoites of... (Review)
Review
Plasmodium vivax contributes significantly to global malaria morbidity. Key advances include the discovery of pathways facilitating invasion by P. vivax merozoites of nascent reticulocytes, crucial for vaccine development. Humanized mouse models and hepatocyte culture systems have enhanced understanding of hypnozoite biology. The spleen has emerged as a major reservoir for asexual vivax parasites, replicating in an endosplenic life cycle, and contributing to recurrent and chronic infections, systemic inflammation, and anemia. Splenic accumulation of uninfected red cells is the predominant cause of anemia. Recurring and chronic infections cause progressive anemia, malnutrition, and death in young children in high-transmission regions. Endothelial activation likely contributes to vivax-associated organ dysfunction. The many recent advances in vivax pathobiology should help guide new approaches to prevention and management.
PubMed: 38749866
DOI: 10.1016/j.pt.2024.04.015 -
Revista Do Instituto de Medicina... 2024This study reports a challenging diagnosis of Plasmodium ovale malaria in a Colombian citizen returning from Cameroon. Initial microscopy screenings conducted at two...
This study reports a challenging diagnosis of Plasmodium ovale malaria in a Colombian citizen returning from Cameroon. Initial microscopy screenings conducted at two private hospitals yielded conflicting results, with the first showing negative smears and the second diagnosing P. vivax. Subsequent microscopy examinations at two government laboratories identified P. ovale, although the routine species-specific PCR strategy was negative. PCR confirmation was finally obtained when P. ovale wallikeri primers were used. Although P. ovale is not frequently found in Colombia, there is a clear need to include both P. ovale curtisi and P. ovale wallikeri in the molecular diagnostic strategy. Such need stems primarily from their extended latency period, which affects travelers, the increasing number of African migrants, and the importance of accurately mapping the distribution of Plasmodium species in Colombia.
Topics: Plasmodium ovale; Humans; Malaria; Colombia; Polymerase Chain Reaction; Travel; Male; DNA, Protozoan; Adult; Cameroon
PubMed: 38747850
DOI: 10.1590/S1678-9946202466029