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Trends in Parasitology Feb 2023Plasmodium malariae is a 'neglected malaria parasite' in as much as the amount of research conducted on it pales into insignificance when compared to that pertaining to... (Review)
Review
Plasmodium malariae is a 'neglected malaria parasite' in as much as the amount of research conducted on it pales into insignificance when compared to that pertaining to Plasmodium falciparum and Plasmodium vivax, its more notorious and pathogenic cousins. There has, however, been an increase in interest in this parasite over the past decade. Principally, this is because of the increasing use of sensitive molecular detection techniques that have revealed a wider than previously recorded prevalence in some regions (particularly in Africa), and high numbers of chronic, asymptomatic infections.
Topics: Animals; Humans; Malaria; Parasites; Plasmodium malariae; Plasmodium falciparum; Plasmodium vivax
PubMed: 36517330
DOI: 10.1016/j.pt.2022.11.008 -
Critical Reviews in Microbiology Feb 2021is often reported as a benign malaria parasite. There are limited data on its biology and disease burden in sub-Saharan Africa (sSA) possibly due to the unavailability... (Review)
Review
is often reported as a benign malaria parasite. There are limited data on its biology and disease burden in sub-Saharan Africa (sSA) possibly due to the unavailability of specific and affordable tools for routine diagnosis and large epidemiology studies. In addition, occurs at low parasite densities and in co-infections with other species, predominately . The paucity of data on infections limits the capacity to accurately determine its contribution to malaria and the effect of control interventions against on its prevalence. Here, we summarise the current knowledge on epidemiology in sSA - overall prevalence ranging from 0-32%, as detected by different diagnostic methods; seroprevalence ranging from 0-56% in three countries (Mozambique, Benin and Zimbabwe), and explore the future application of next-generation sequencing technologies as a tool for enriching genomic epidemiology. This will provide insights into important adaptive mechanisms of this neglected non-falciparum species, including antimalarial drug resistance, local and regional parasite transmission patterns and genomic signatures of selection. Improved diagnosis and genomic surveillance of non-falciparum malaria parasites in Africa would be helpful in evaluating progress towards elimination of all human species.
Topics: Africa; Animals; Antibodies, Protozoan; Biomedical Research; Humans; Malaria; Neglected Diseases; Plasmodium malariae
PubMed: 33507842
DOI: 10.1080/1040841X.2020.1838440 -
Malaria Journal May 2019Plasmodium malariae is the most neglected of the six human malaria species and it is still unknown which is the mechanism underlying the long latency of this Plasmodium. (Review)
Review
BACKGROUND
Plasmodium malariae is the most neglected of the six human malaria species and it is still unknown which is the mechanism underlying the long latency of this Plasmodium.
CASE PRESENTATION
A case of PCR-confirmed P. malariae recurrence in a 52-year old Italian man was observed 5 months after a primary attack. In the interval between the two observed episodes of malaria the patient denied any further stay in endemic areas except for a visit to Libya, a country considered malaria-free. Genomic DNA of the P. malariae strain using five microsatellites (PM2, PM9, PM11, PM25, PM34) and the antigen marker of circumsporozoite (csp) was amplified and sequenced. Analysis of polymorphisms of the P. malariae csp central repeat region showed differences between the strains responsible of the first and second episode of malaria. A difference in the allele size was also observed for the sequence analysis of PM2 microsatellites.
CONCLUSIONS
Plasmodium malariae is a challenging human malaria parasite and even with the use of molecular techniques the pathogenesis of recurrent episodes cannot be precisely explained.
Topics: Adult; Aged; Antimalarials; Female; Genome, Protozoan; Humans; Infant; Malaria; Male; Microsatellite Repeats; Middle Aged; Phylogeny; Plasmodium malariae; Polymerase Chain Reaction; Polymorphism, Genetic; Recurrence; Young Adult
PubMed: 31088460
DOI: 10.1186/s12936-019-2806-y -
The Journal of Infectious Diseases Mar 2020
Topics: Humans; Malaria; Plasmodium malariae; Plasmodium ovale
PubMed: 30855671
DOI: 10.1093/infdis/jiz103 -
Clinical Microbiology Reviews Oct 2007A review of the life history of Plasmodium malariae, the quartan malaria parasite of humans, is presented. Much of the information is based on data obtained from induced... (Review)
Review
A review of the life history of Plasmodium malariae, the quartan malaria parasite of humans, is presented. Much of the information is based on data obtained from induced infections in humans who were given malaria therapy for the treatment of neurosyphilis between 1940 and 1963. Prepatent periods (i.e., the time until the first day of parasite detection) fever episodes, and maximum parasitemias as a result of infection with P. malariae were obtained and are presented. Experimental and known vectors of the parasite are also discussed. Splenectomized chimpanzees and New World monkeys are readily infected and serve as sources of parasites and antigens for diagnostic and molecular studies. South American monkeys are naturally infected with a parasite known as Plasmodium brasilianum. This parasite appears to be P. malariae that has adapted from humans to grow in monkeys, probably within the last 500 years. Infection with P. malariae is associated with the production of immune complexes in the kidneys and the associated nephrotic syndrome. The essential lesions are a thickening of the glomerular basement membrane and endocapillary cell proliferation. Studies of monkeys infected with P. malariae indicate the same pathology as that demonstrated in humans.
Topics: Animals; Anopheles; Erythrocytes; Humans; Life Cycle Stages; Malaria; Plasmodium malariae
PubMed: 17934075
DOI: 10.1128/CMR.00027-07 -
Trends in Parasitology Jun 2007Although Plasmodium malariae was first described as an infectious disease of humans by Golgi in 1886 and Plasmodium ovale identified by Stevens in 1922, there are still... (Review)
Review
Although Plasmodium malariae was first described as an infectious disease of humans by Golgi in 1886 and Plasmodium ovale identified by Stevens in 1922, there are still large gaps in our knowledge of the importance of these infections as causes of malaria in different parts of the world. They have traditionally been thought of as mild illnesses that are caused by rare and, in case of P. ovale, short-lived parasites. However, recent advances in sensitive PCR diagnosis are causing a re-evaluation of this assumption. Low-level infection seems to be common across malaria-endemic areas, often as complex mixed infections. The potential interactions of P. malariae and P. ovale with Plasmodium falciparum and Plasmodium vivax might explain some basic questions of malaria epidemiology, and understanding these interactions could have an important influence on the deployment of interventions such as malaria vaccines.
Topics: Adolescent; Adult; Animals; Child; Child, Preschool; Humans; Infant; Infant, Newborn; Malaria; Microscopy; Plasmodium malariae; Plasmodium ovale; Polymerase Chain Reaction; Prevalence
PubMed: 17459775
DOI: 10.1016/j.pt.2007.04.009 -
Malaria Journal May 2022During the twentieth century, there was an explosion in understanding of the malaria parasites infecting humans and wild primates. This was built on three main data... (Review)
Review
During the twentieth century, there was an explosion in understanding of the malaria parasites infecting humans and wild primates. This was built on three main data sources: from detailed descriptive morphology, from observational histories of induced infections in captive primates, syphilis patients, prison inmates and volunteers, and from clinical and epidemiological studies in the field. All three were wholly dependent on parasitological information from blood-film microscopy, and The Primate Malarias" by Coatney and colleagues (1971) provides an overview of this knowledge available at that time. Here, 50 years on, a perspective from the third decade of the twenty-first century is presented on two pairs of primate malaria parasite species. Included is a near-exhaustive summary of the recent and current geographical distribution for each of these four species, and of the underlying molecular and genomic evidence for each. The important role of host transitions in the radiation of Plasmodium spp. is discussed, as are any implications for the desired elimination of all malaria species in human populations. Two important questions are posed, requiring further work on these often ignored taxa. Is Plasmodium brasilianum, circulating among wild simian hosts in the Americas, a distinct species from Plasmodium malariae? Can new insights into the genomic differences between Plasmodium ovale curtisi and Plasmodium ovale wallikeri be linked to any important differences in parasite morphology, cell biology or clinical and epidemiological features?
Topics: Animals; Genomics; Humans; Malaria; Parasites; Plasmodium malariae; Plasmodium ovale; Primates
PubMed: 35505317
DOI: 10.1186/s12936-022-04151-4 -
The Journal of Infectious Diseases Apr 2024
Topics: Humans; Plasmodium ovale; Plasmodium malariae; Malaria; Plasmodium
PubMed: 38243611
DOI: 10.1093/infdis/jiae015 -
Malaria Journal Nov 2016The Greater Mekong Subregion is aiming to achieve regional malaria elimination by 2030. Though a shift in malaria parasite species predominance by Plasmodium vivax has...
BACKGROUND
The Greater Mekong Subregion is aiming to achieve regional malaria elimination by 2030. Though a shift in malaria parasite species predominance by Plasmodium vivax has been recently documented, the transmission of the two minor Plasmodium species, Plasmodium malariae and Plasmodium ovale spp., is poorly characterized in the region. This study aims to determine the prevalence of these minor species in the China-Myanmar border area and their genetic diversity.
METHODS
Epidemiology study was conducted during passive case detection in hospitals and clinics in Myanmar and four counties in China along the China-Myanmar border. Cross-sectional surveys were conducted in villages and camps for internally displaced persons to determine the prevalence of malaria infections. Malaria infections were diagnosed initially by microscopy and later in the laboratory using nested PCR for the SSU rRNA genes. Plasmodium malariae and P. ovale infections were confirmed by sequencing the PCR products. The P. ovale subtypes were determined by sequencing the Pocytb, Pocox1 and Pog3p genes. Parasite populations were evaluated by PCR amplification and sequencing of the MSP-1 genes. Antifolate sensitivity was assessed by sequencing the dhfr-ts and dhps genes from the P. malariae and P. ovale isolates.
RESULTS
Analysis of 2701 blood samples collected from the China-Myanmar border by nested PCR targeting the parasite SSU rRNA genes identified 561 malaria cases, including 161 Plasmodium falciparum, 327 P. vivax, 66 P. falciparum/P. vivax mixed infections, 4 P. malariae and 3 P. ovale spp. P. vivax and P. falciparum accounted for >60 and ~30% of all malaria cases, respectively. In comparison, the prevalence of P. malariae and P. ovale spp. was very low and only made up ~1% of all PCR-positive cases. Nevertheless, these two species were often misidentified as P. vivax infections or completely missed by microscopy even among symptomatic patients. Phylogenetic analysis of the SSU rRNA, Pocytb, Pocox1 and Pog3p genes confirmed that the three P. ovale spp. isolates belonged to the subtype P. ovale curtisi. Low-level genetic diversity was detected in the MSP-1, dhfr and dhps genes of these minor parasite species, potentially stemming from the low prevalence of these parasites preventing their mixing. Whereas most of the dhfr and dhps positions equivalent to those conferring antifolate resistance in P. falciparum and P. vivax were wild type, a new mutation S113C corresponding to the S108 position in pfdhfr was identified in two P. ovale curtisi isolates.
CONCLUSIONS
The four human malaria parasite species all occurred sympatrically at the China-Myanmar border. While P. vivax has become the predominant species, the two minor parasite species also occurred at very low prevalence but were often misidentified or missed by conventional microscopy. These minor parasite species displayed low levels of polymorphisms in the msp-1, dhfr and dhps genes.
Topics: Adult; Child; China; Cluster Analysis; Cross-Sectional Studies; DNA, Protozoan; DNA, Ribosomal; Drug Resistance; Female; Genetic Variation; Humans; Malaria; Male; Microscopy; Myanmar; Phylogeny; Plasmodium falciparum; Plasmodium malariae; Plasmodium ovale; Plasmodium vivax; Polymerase Chain Reaction; Prevalence; Protozoan Proteins; RNA, Ribosomal, 18S; Sequence Analysis, DNA; Young Adult
PubMed: 27846879
DOI: 10.1186/s12936-016-1605-y -
Acta Medica Indonesiana 2004
Topics: Adult; Animals; Humans; Malaria; Male; Plasmodium malariae; Remission, Spontaneous
PubMed: 15673945
DOI: No ID Found