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Emerging Infectious Diseases Apr 2017In Africa, control programs that target primarily Plasmodium falciparum are inadequate for eliminating malaria. To learn more about prevalence and genetic variability of...
In Africa, control programs that target primarily Plasmodium falciparum are inadequate for eliminating malaria. To learn more about prevalence and genetic variability of P. malariae in Africa, we examined blood samples from 663 asymptomatic and 245 symptomatic persons from western Kenya during June-August of 2014 and 2015. P. malariae accounted for 5.3% (35/663) of asymptomatic infections and 3.3% (8/245) of clinical cases. Among asymptomatic persons, 71% (32/45) of P. malariae infections detected by PCR were undetected by microscopy. The low sensitivity of microscopy probably results from the significantly lower parasitemia of P. malariae. Analyses of P. malariae circumsporozoite protein gene sequences revealed high genetic diversity among P. malariae in Africa, but no clear differentiation among geographic populations was observed. Our findings suggest that P. malariae should be included in the malaria elimination strategy in Africa and highlight the need for sensitive and field-applicable methods to identify P. malariae in malaria-endemic areas.
Topics: Adolescent; Animals; Case-Control Studies; Child; Child, Preschool; Female; Genetic Variation; Humans; Kenya; Malaria; Male; Phylogeny; Plasmodium malariae; Prevalence; Protozoan Proteins; Rabbits
PubMed: 28322694
DOI: 10.3201/eid2304.161245 -
Proceedings (Baylor University. Medical... 2023is a genus of parasites that comprises different species. The species and are known to cause a vector-borne illness called malaria, and among these, is known to... (Review)
Review
is a genus of parasites that comprises different species. The species and are known to cause a vector-borne illness called malaria, and among these, is known to cause major complications. The vector, the Anopheles mosquito, is commonly found in warmer regions close to the equator, and hence transmission and numbers of cases tend to be higher in Sub-Saharan Africa, South Asia, and Central America. The number of cases of malaria in the United States has remained stable over the years with low transmission rates, and the disease is mostly seen in the population with a recent travel history to endemic regions. The main reason behind this besides the weather conditions is that economically developed countries have eliminated mosquitos. However, there have been reports of locally reported cases with in areas such as Florida and Texas in patients with no known travel history. This paper aims to familiarize US physicians with the pathophysiology, clinical features, and diagnostic modalities of malaria, as well as available treatment options.
PubMed: 37829240
DOI: 10.1080/08998280.2023.2255514 -
Parasitology Nov 2023Of the 5 human malarial parasites, and are the most prevalent species globally, while and are less prevalent and typically occur as mixed-infections. , previously... (Review)
Review
Of the 5 human malarial parasites, and are the most prevalent species globally, while and are less prevalent and typically occur as mixed-infections. , previously considered a non-human primate (NHP) infecting species, is now a cause of human malaria in Malaysia. The other NHP species, , , , , and cause malaria in primates, which are mainly reported in southeast Asia and South America. The non- NHP species also emerged and were found to cross-transmit from their natural hosts (NHP) – to human hosts in natural settings. Here we have reviewed and collated data from the literature on the NHPs-to-human-transmitting species. It was observed that the natural transmission of these NHP parasites to humans had been reported from 2010 onwards. This study shows that: (1) the majority of the non- NHP mixed species infecting human cases were from Yala province of Thailand; (2) mono/mixed infections with other human-infecting species were prevalent in Malaysia and Thailand and (3) and were found in Central and South America.
Topics: Animals; Humans; Malaria; Plasmodium knowlesi; Primates; Asia, Southeastern; Plasmodium vivax
PubMed: 37929579
DOI: 10.1017/S003118202300077X -
Microorganisms Jan 2021In the south and southeast regions of Brazil, cases of malaria occur outside the endemic Amazon region near the Atlantic Forest in some coastal states, where is the... (Review)
Review
In the south and southeast regions of Brazil, cases of malaria occur outside the endemic Amazon region near the Atlantic Forest in some coastal states, where is the recognized parasite. Characteristics of cases and vectors, especially , raise the hypothesis of a zoonosis with simians as reservoirs. The present review aims to report on investigations of the disease over a 23-year period. Two main sources have provided epidemiological data: the behavior of vectors and the genetic and immunological aspects of spp. obtained from humans, simians, and spp. mosquitoes. is the most captured species in the forest canopy and is the recognized vector. The similarity between and and that between and shared between simian and human hosts and the involvement of the same vector in the transmission to both hosts suggest interspecies transfer of the parasites. Finally, recent evidence points to the presence of in a silent cycle, detected only by molecular methods in asymptomatic individuals and . In the context of malaria elimination, it is paramount to assemble data about transmission in such non-endemic low-incidence areas.
PubMed: 33430150
DOI: 10.3390/microorganisms9010132 -
Malaria Journal Nov 2022Indonesia is progressing towards malaria elimination. To achieve this goal, intervention measures must be addressed to cover all Plasmodium species. Comprehensive...
BACKGROUND
Indonesia is progressing towards malaria elimination. To achieve this goal, intervention measures must be addressed to cover all Plasmodium species. Comprehensive control measures and surveillance programmes must be intensified. This study aims to determine the prevalence of microscopic and submicroscopic malaria in Langkat district, North Sumatera Province, Indonesia.
METHODS
A cross-sectional survey was conducted in six villages in Langkat district, North Sumatera Province in June 2019. Data were recorded using a standardized questionnaire. Finger pricked blood samples were obtained for malaria examination using rapid diagnostic test, thick and thin blood smears, and polymerase chain reaction.
RESULTS
A total of 342 individuals were included in the study. Of them, one (0.3%) had a microscopic Plasmodium malariae infection, no positive RDT examination, and three (0.9%) were positive for P. malariae (n = 1) and Plasmodium knowlesi (n = 2). The distribution of bed net ownership was owned by 40% of the study participants. The participants had a house within a radius of 100-500 m from the forest (86.3%) and had the housing material of cement floor (56.1%), a tin roof (82.2%), wooden wall (35.7%), bamboo wall (28.1%), and brick wall (21.6%).
CONCLUSION
Malaria incidence has substantially decreased in Langkat, North Sumatera, Indonesia. However, submicroscopic infection remains in the population and may contribute to further transmission. Surveillance should include the detection of microscopic undetected parasites, to enable the achievement of malaria elimination.
Topics: Humans; Plasmodium knowlesi; Plasmodium malariae; Cross-Sectional Studies; Indonesia; Malaria; Plasmodium falciparum
PubMed: 36333701
DOI: 10.1186/s12936-022-04335-y -
Frontiers in Genetics 2022Many standard-textbook population-genetic results apply to a wide range of species. Sometimes, however, population-genetic models and principles need to be tailored to a...
Many standard-textbook population-genetic results apply to a wide range of species. Sometimes, however, population-genetic models and principles need to be tailored to a particular species. This is particularly true for malaria, which next to tuberculosis and HIV/AIDS ranks among the economically most relevant infectious diseases. Importantly, malaria is not one disease-five human-pathogenic species of exist. is not only the most severe form of human malaria, but it also causes the majority of infections. The second most relevant species, , is already considered a neglected disease in several endemic areas. All human-pathogenic species have distinct characteristics that are not only crucial for control and eradication efforts, but also for the population-genetics of the disease. This is particularly true in the context of selection. Namely, fitness is determined by so-called fitness components, which are determined by the parasites live-history, which differs between malaria species. The presence of hypnozoites, i.e., dormant liver-stage parasites, which can cause disease relapses, is a distinct feature of and sp. In inactivated blood-stage parasites can cause a recrudescence years after the infection was clinically cured. To properly describe population-genetic processes, such as the spread of anti-malarial drug resistance, these features must be accounted for appropriately. Here, we introduce and extend a population-genetic framework for the evolutionary dynamics of malaria, which applies to all human-pathogenic malaria species. The model focuses on, but is not limited to, the spread of drug resistance. The framework elucidates how the presence of dormant liver stage or inactivated blood stage parasites that act like seed banks delay evolutionary processes. It is shown that, contrary to standard population-genetic theory, the process of selection and recombination cannot be decoupled in malaria. Furthermore, we discuss the connection between haplotype frequencies, haplotype prevalence, transmission dynamics, and relapses or recrudescence in malaria.
PubMed: 36406132
DOI: 10.3389/fgene.2022.1030463 -
The American Journal of Tropical... May 2021In 2016, we reported the presence of Plasmodium vivax in Botswana through active case detection. A real-time PCR was used during a similar study in 10 districts to...
In 2016, we reported the presence of Plasmodium vivax in Botswana through active case detection. A real-time PCR was used during a similar study in 10 districts to assess changes in the P. vivax prevalence. We assessed 1,614 children (2-13 years of age) for hemoglobin (Hb; g/dL) and Plasmodium parasites. The median age of all participants was 5.0 years (25th percentile, 3 years; 75th percentile, 8 years). The median Hb (g/dL) level was 12.1, but 18.3% of the participants had anemia (Hb < 11.0 g/dL); these participants were clustered in the younger than 5 years age group in all districts (P < 0.001). The risk of anemia decreased with age 5 years or older (odds ratio [OR], 0.26; 95% confidence interval [CI], 0.197-0.34; P < 0.001). The prevalence rates of Plasmodium parasites were as follows: P. vivax, 12.7%; P. falciparum, 12.7%; P. malariae, 0.74%; and P. ovale (P. ovale curtisi), 0.68%. Mixed infection rates were as follows: P. falciparum and P. vivax, 2.35%; P. falciparum and P. ovale curtisi, 0.56%; P. vivax and P. malariae, 0.06%; and P. falciparum and P. malariae, 0.68%. The infections were largely asymptomatic (99.6%). Using logistic regression, the risk of infection with P. vivax was highest in Kweneng East (OR, 6.2; 95% CI, 2.9-13.1), followed by South East (OR, 5.6; 95% CI, 2.5-12.3) and Ngami (OR, 5.1; 95% CI, 2.2-12.0). Compared to the risk of infection for children younger than 5 years, the risk of infection decreased for children 5 years or older in regions with high rates of P. vivax and P. falciparum infections. P. vivax and P. falciparum have expanded within the asymptomatic population in Botswana; therefore, careful attention is required for their elimination.
Topics: Adolescent; Asymptomatic Infections; Botswana; Child; Child, Preschool; DNA, Protozoan; Humans; Malaria, Falciparum; Malaria, Vivax; Odds Ratio; Plasmodium falciparum; Plasmodium vivax; Prevalence; Real-Time Polymerase Chain Reaction
PubMed: 33939635
DOI: 10.4269/ajtmh.21-0083 -
Tropical Parasitology 2020Malaria, a mosquito-transmitted parasitic disease, has been targeted for elimination in many parts of the world. For many years, and have been known to cause malaria... (Review)
Review
Malaria, a mosquito-transmitted parasitic disease, has been targeted for elimination in many parts of the world. For many years, and have been known to cause malaria in humans. Now, is considered to be an important cause of malaria, especially in Southeast Asia. The emergence of zoonotic implication is a challenge in the elimination efforts of malaria in Southeast Asia. is known to cause severe complicated malaria in humans. parasite is transmitted between humans and wild macaque through mosquito vectors. It appears that the malaria disease severity and host immune evasion depend on antigenic variation exhibited at the surface of the infected erythrocyte. is sensitive to antimalarial drug artemisinin. Identification of vector species, their biting behavior, timely correct diagnosis, and treatment are important steps in disease management and control. There is a need to identify and implement effective intervention measures to cut the chain of transmissions from animals to humans. The zoonotic malaria definitely poses a significant challenge in elimination and subsequent eradication of all types of malaria from this globe.
PubMed: 32775284
DOI: 10.4103/tp.TP_17_18 -
Iranian Journal of Parasitology 2016Malaria is the most important transfusion-transmitted infection (TTI) in worldwide after viral hepatitis and human immunodeficiency virus (HIV) infection. The main... (Review)
Review
BACKGROUND
Malaria is the most important transfusion-transmitted infection (TTI) in worldwide after viral hepatitis and human immunodeficiency virus (HIV) infection. The main objective of the present study was to review and evaluate the transmission of malaria via blood transfusion in Iran.
METHODS
A literature search was done without time limitation in the electronic databases as follows: PubMed, Scopus, Google Scholar, Web of Science, Science Direct, scientific information database (SID), Magiran, IranMedex and Irandoc. The searches were limited to the published papers to English and Persian languages.
RESULTS
Six papers were eligible. From 1963 to 1983, 344 cases of Transfusion-transmitted malaria (TTM) had been reported from different provinces of Iran. The most prevalent species of involved in investigated cases of TTM was (79.24%). The screening results of 1,135 blood donors for malaria were negative by microscopic examination of peripheral blood smears and rapid diagnostic test (RDT) methods.
CONCLUSION
Lack of TTM report from Iran in the last three decades indicates that the screening of blood donors through interviewing (donor selection) may be effective in the prevention of the occurrence of transfusion-transmitted malaria.
PubMed: 28096847
DOI: No ID Found -
Frontiers in Public Health 2014The four main Plasmodium species that cause human malaria, Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, and Plasmodium ovale, are transmitted between... (Review)
Review
The four main Plasmodium species that cause human malaria, Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, and Plasmodium ovale, are transmitted between humans by mosquito vectors belonging to the genus Anopheles. It has recently become evident that Plasmodium knowlesi, a parasite that typically infects forest macaque monkeys, can be transmitted by anophelines to cause malaria in humans in Southeast Asia. Plasmodium knowlesi infections are frequently misdiagnosed microscopically as P. malariae. Direct human to human transmission of P. knowlesi by anophelines has not yet been established to occur in nature. Knowlesi malaria must therefore be presently considered a zoonotic disease. Polymerase chain reaction is now the definitive method for differentiating P. knowlesi from P. malariae and other human malaria parasites. The origin of P. falciparum and P. vivax in African apes are examples of ancient zoonoses that may be continuing at the present time with at least P. vivax, and possibly P. malariae and P. ovale. Other non-human primate malaria species, e.g., Plasmodium cynomolgi in Southeast Asia and Plasmodium brasilianum and Plasmodium simium in South America, can be transmitted to humans by mosquito vectors further emphasizing the potential for continuing zoonoses. The potential for zoonosis is influenced by human habitation and behavior as well as the adaptive capabilities of parasites and vectors. There is insufficient knowledge of the bionomics of Anopheles vector populations relevant to the cross-species transfer of malaria parasites and the real extent of malaria zoonoses. Appropriate strategies, based on more research, need to be developed for the prevention, diagnosis, and treatment of zoonotic malaria.
PubMed: 25184118
DOI: 10.3389/fpubh.2014.00123