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PloS One 2020Plasmodium ovale can infect humans, causing malaria disease. We aimed to investigate the severity and mortality of severe P. ovale infection to increase the awareness of... (Meta-Analysis)
Meta-Analysis
Plasmodium ovale can infect humans, causing malaria disease. We aimed to investigate the severity and mortality of severe P. ovale infection to increase the awareness of physicians regarding the prognosis of this severe disease and outcome-related deaths in countries in which this disease is endemic. Articles that were published in the PubMed, Scopus, and ISI Web of Science databases prior to January 5, 2020 and reported the prevalence of severe P. ovale infection were systematically searched and reviewed. Studies that mainly reported severe P. ovale infection according to the 2014 WHO criteria for the treatment of malaria were included. Two reviewers selected, identified, assessed, and extracted data from studies independently. The pooled prevalence of severe P. ovale mono-infections was estimated using the command "metaprop case population, random/fixed", which yielded the pooled estimate, 95% confidence interval (CI) and the I2 value, indicating the level of heterogeneity. Meta-analyses of the proportions were performed using a random-effects model to explore the different proportions of severity between patients with P. ovale and those with other Plasmodium species infections. Among the eight studies that were included and had a total of 1,365 ovale malaria cases, the pooled prevalence of severe P. ovale was 0.03 (95% CI = 0.03-0.05%, I2 = 54.4%). Jaundice (1.1%), severe anemia (0.88%), and pulmonary impairments (0.59%) were the most common severe complications found in patients infected with P. ovale. The meta-analysis demonstrated that a smaller proportion of patients with P. ovale than of patients with P. falciparum had severe infections (P-value = 0.01, OR = 0.36, 95% CI = 0.16-0.81, I2 = 72%). The mortality rate of severe P. ovale infections was 0.15% (2/1,365 cases). Although severe complications of P. ovale infections in patients are rare, it is very important to increase the awareness of physicians regarding the prognosis of severe P. ovale infections in patients, especially in a high-risk population.
Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Female; Humans; Infant; Malaria; Male; Middle Aged; Plasmodium falciparum; Plasmodium ovale; Prevalence
PubMed: 32559238
DOI: 10.1371/journal.pone.0235014 -
PLoS Neglected Tropical Diseases Jan 2023Plasmodium parasites caused 241 million cases of malaria and over 600,000 deaths in 2020. Both P. falciparum and P. ovale are endemic to Mali and cause clinical malaria,...
Plasmodium parasites caused 241 million cases of malaria and over 600,000 deaths in 2020. Both P. falciparum and P. ovale are endemic to Mali and cause clinical malaria, with P. falciparum infections typically being more severe. Here, we sequenced RNA from nine pediatric blood samples collected during infections with either P. falciparum or P. ovale, and characterized the host and parasite gene expression profiles. We found that human gene expression varies more between individuals than according to the parasite species causing the infection, while parasite gene expression profiles cluster by species. Additionally, we characterized DNA polymorphisms of the parasites directly from the RNA-seq reads and found comparable levels of genetic diversity in both species, despite dramatic differences in prevalence. Our results provide unique insights into host-pathogen interactions during malaria infections and their variations according to the infecting Plasmodium species, which will be critical to develop better elimination strategies against all human Plasmodium parasites.
Topics: Child; Humans; Malaria; Malaria, Falciparum; Plasmodium falciparum; Plasmodium ovale; Transcriptome
PubMed: 36696438
DOI: 10.1371/journal.pntd.0010802 -
Nature Communications Oct 2023Reports suggest non-falciparum species are an underappreciated cause of malaria in sub-Saharan Africa but their epidemiology is ill-defined, particularly in highly...
Reports suggest non-falciparum species are an underappreciated cause of malaria in sub-Saharan Africa but their epidemiology is ill-defined, particularly in highly malaria-endemic regions. We estimated incidence and prevalence of PCR-confirmed non-falciparum and Plasmodium falciparum malaria infections within a longitudinal study conducted in Kinshasa, Democratic Republic of Congo (DRC) between 2015-2017. Children and adults were sampled at biannual household surveys and routine clinic visits. Among 9,089 samples from 1,565 participants, incidences of P. malariae, P. ovale spp., and P. falciparum infections by 1-year were 7.8% (95% CI: 6.4%-9.1%), 4.8% (95% CI: 3.7%-5.9%) and 57.5% (95% CI: 54.4%-60.5%), respectively. Non-falciparum prevalences were higher in school-age children, rural and peri-urban sites, and P. falciparum co-infections. P. falciparum remains the primary driver of malaria in the DRC, though non-falciparum species also pose an infection risk. As P. falciparum interventions gain traction in high-burden settings, continued surveillance and improved understanding of non-falciparum infections are warranted.
Topics: Child; Adult; Humans; Plasmodium ovale; Plasmodium malariae; Democratic Republic of the Congo; Longitudinal Studies; Malaria, Falciparum; Malaria; Prevalence; Plasmodium falciparum
PubMed: 37857597
DOI: 10.1038/s41467-023-42190-w -
Clinical Infectious Diseases : An... Dec 2021In a cross-sectional molecular study in the Democratic Republic of the Congo, 78% of households had ≥1 member infected with Plasmodium falciparum, Plasmodium vivax,...
In a cross-sectional molecular study in the Democratic Republic of the Congo, 78% of households had ≥1 member infected with Plasmodium falciparum, Plasmodium vivax, and/or Plasmodium ovale spp.; 47% of children and 33% of adults tested positive for ≥1 species. Risk factors varied by species and age group.
Topics: Adult; Child; Cross-Sectional Studies; Democratic Republic of the Congo; Humans; Malaria, Falciparum; Plasmodium falciparum; Plasmodium ovale; Plasmodium vivax; Prevalence
PubMed: 33238298
DOI: 10.1093/cid/ciaa1772 -
MedRxiv : the Preprint Server For... Apr 2023Increasing reports suggest that non-falciparum species are an underappreciated cause of malaria in sub-Saharan Africa, but their epidemiology is not well-defined. This...
BACKGROUND
Increasing reports suggest that non-falciparum species are an underappreciated cause of malaria in sub-Saharan Africa, but their epidemiology is not well-defined. This is particularly true in regions of high endemicity such as the Democratic Republic of Congo (DRC), where 12% of the world's malaria cases and 13% of deaths occur.
METHODS AND FINDINGS
The cumulative incidence and prevalence of and spp. infection detected by real-time PCR were estimated among children and adults within a longitudinal study conducted in seven rural, peri-urban, and urban sites from 2015-2017 in Kinshasa Province, DRC. Participants were sampled at biannual household survey visits (asymptomatic) and during routine health facility visits (symptomatic). Participant-level characteristics associated with non-falciparum infections were estimated for single- and mixed-species infections. Among 9,089 samples collected from 1,565 participants over a 3-year period, the incidence of and spp. infection was 11% (95% CI: 9%-12%) and 7% (95% CI: 5%-8%) by one year, respectively, compared to a 67% (95% CI: 64%-70%) one-year cumulative incidence of infection. Incidence continued to rise in the second year of follow-up, reaching 26% and 15% in school-age children (5-14yo) for and spp., respectively. Prevalence of spp., and infections during household visits were 3% (95% CI: 3%-4%), 1% (95% CI: 1%-2%), and 35% (95% CI: 33%-36%), respectively. Non-falciparum malaria was more prevalent in rural and peri-urban vs. urban sites, in school-age children, and among those with P. falciparum co-infection. A crude association was detected between and any anemia in the symptomatic clinic population, although this association did not hold when stratified by anemia severity. No crude associations were detected between non-falciparum infection and fever prevalence.
CONCLUSIONS
remains the primary driver of malaria morbidity and mortality in the DRC. However, non-falciparum species also pose an infection risk across sites of varying urbanicity and malaria endemicity within Kinshasa, DRC, particularly among children under 15 years of age. As interventions gain traction in high-burden settings like the DRC, continued surveillance and improved understanding of non-falciparum infections are warranted.
PubMed: 37790376
DOI: 10.1101/2023.04.20.23288826 -
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 -
Infectious Diseases of Poverty Aug 2021China has reached important milestones in the elimination of malaria. However, the numbers of imported recurrent cases of Plasmodium vivax and P. ovale are gradually...
BACKGROUND
China has reached important milestones in the elimination of malaria. However, the numbers of imported recurrent cases of Plasmodium vivax and P. ovale are gradually increasing, which increases the risk of malaria re-establishment in locations where Anopheles mosquitoes exist. The aim of this study is to characterize the epidemiological profiles of imported recurrent P. vivax and P. ovale cases, quantifying the recurrence burden and guiding the development of appropriate public health intervention strategies.
METHODS
Individual-level data of imported recurrent P. vivax and P. ovale cases were collected from 2013 to 2020 in China via the Parasitic Diseases Information Reporting Management System. Demographic characteristics, temporal and spatial distributions, and the interval from previous infection to recurrence were analyzed by SAS, ArcGIS and GraphPad Prism software, respectively, to explore the epidemiological profiles of imported recurrent cases.
RESULTS
A total of 307 imported recurrent cases, including 179 P. vivax and 128 P. ovale cases, were recorded. The majority of cases occurred in males (P. vivax 91.1%, P. ovale 93.8%) and migrant workers (P. vivax 43.2%, P. ovale 44.7%). Individuals aged 30-39 years had the highest P. vivax and P. ovale recurrent infection rates, respectively. The number of imported recurrent cases of infection by these two malaria species increased from 2013 to 2018, and P. vivax infection showed well-defined seasonality, with two peaks in February and June, respectively. More than 90% of patients with recurrent cases did not receive radical treatment for previous infection. Most imported recurrent P. vivax cases were reported in Yunnan Province and were imported from Myanmar, Ethiopia, and Pakistan, while most recurrent P. ovale cases were reported in southern China and primarily imported from Cameroon, Ghana, and Nigeria. The intervals from previous malaria infection to recurrence among different continents were significantly different (P = 0.0016) for P. vivax malaria but not for P. ovale malaria (P = 0.2373).
CONCLUSIONS
The large number of imported recurrent cases has been a major challenge in the prevention of malaria re-establishment in China. This study provides evidence to guide the development of appropriate public health intervention strategies for imported recurrent P. vivax and P. ovale cases.
Topics: Animals; Anopheles; China; Humans; Malaria; Male; Plasmodium ovale; Plasmodium vivax
PubMed: 34425898
DOI: 10.1186/s40249-021-00896-3 -
Microbiology Spectrum Jun 2023Malaria treatments resulted in the decline of the deadliest Plasmodium falciparum globally while species, such as , infections have been increasingly detected across...
Malaria treatments resulted in the decline of the deadliest Plasmodium falciparum globally while species, such as , infections have been increasingly detected across sub-Saharan Africa. Currently, no experimental drug sensitivity data are available to guide effective treatment and management of infections, which is necessary for effective malaria elimination. We conducted a prospective study to evaluate epidemiology over 1 year and determined susceptibility of the field isolates to existing and lead advanced discovery antimalarial drugs. We report that while P. falciparum dominated both symptomatic and asymptomatic malaria cases, in mono or co-infections caused 7.16% of symptomatic malaria. Frontline antimalarials artesunate and lumefantrine inhibited as potently as P. falciparum. Chloroquine, which has been withdrawn in Ghana, was also highly inhibitory against both and P. falciparum. In addition, and P. falciparum displayed high susceptibility to quinine, comparable to levels observed with chloroquine. Pyrimethamine, which is a major drug for disease massive prevention, also showed great inhibition of , comparable to effects on P. falciparum. Furthermore, we identified strong inhibition of using GNF179, a close analogue of KAF156 imidazolopiperazines, which is a novel class of antimalarial drugs currently in clinical phase II testing. We further demonstrated that the phosphatidylinositol-4-OH kinase (PI4K)-specific inhibitor, KDU691, is highly inhibitory against and P. falciparum field isolates. Our data indicated that existing and lead advanced discovery antimalarial drugs are suitable for the treatment of infections in Ghana. Current malaria control and elimination tools such as drug treatments are not specifically targeting . can form hypnozoite and cause relapsing malaria. is the third most dominant species in Africa and requires radical cure treatment given that it can form liver dormant forms called hypnozoites that escape all safe treatments. The inappropriate treatment of would sustain its transmission in Africa where the medical need is the greatest. This is a hurdle for successful malaria control and elimination. Here, we provided experiment data that were lacking to guide treatment and disease control policy makers using reference antimalarial drugs. We also provided key experimental data for 2 clinical candidate drugs that can be used for prioritization selection of lead candidate's identification for clinical development.
Topics: Humans; Antimalarials; Plasmodium falciparum; Plasmodium ovale; Ghana; Prospective Studies; Malaria; Malaria, Falciparum; Chloroquine
PubMed: 37093000
DOI: 10.1128/spectrum.04916-22 -
Parasitology Research Jun 2016Malaria recurrences after an initially successful therapy and malarial fever occurring a long time after infection are well-known problems in malariology. Currently, two... (Review)
Review
Malaria recurrences after an initially successful therapy and malarial fever occurring a long time after infection are well-known problems in malariology. Currently, two distinct types of malaria recurrences are defined: recrudescence and relapse. A recrudescence is thought to originate from circulating Plasmodium blood stages which do not cause fever before a certain level of a microscopically detectable parasitemia is reached. Contrary, a relapse is thought to originate from quiescent intracellular hepatic parasite stages called hypnozoites. Recrudescences would typically occur in infections due to Plasmodium falciparum. Plasmodium knowlesi, and Plasmodium malariae, whereas relapses would be caused exclusively by Plasmodium vivax and Plasmodium ovale. This schematic view is, however, insufficiently supported by experimental evidence. For instance, hypnozoites of P. ovale have never been experimentally documented. On the other hand, the nonfinding of P. malariae hypnozoites turned into the proof for the nonexistence of P. malariae hypnozoites. Clinical relapse-type recurrences have been observed in both P. ovale and P. malariae infections, and decade-long incubation times have also been reported in P. falciparum infections. We propose a gradual hypothesis in accordance with the continuity concept of biological evolution: both, relapse and recrudescence may be potentially caused by all Plasmodium spp. We hypothesize that the difference between the various Plasmodium spp. is quantitative rather than qualitative: there are Plasmodium spp. which frequently cause relapses such as P. vivax, particularly the P.v. Chesson strain, species which cause relapses less frequently, such as P. ovale and sometimes P. malariae, and species which may exceptionally cause relapses such as P. falciparum. All species may cause recrudescences. As clinical consequences, we propose that 8-aminquinolines may be considered in a relapse-type recrudescence regardless of the causal Plasmodium sp., whereas primaquine relapse prevention might not be routinely indicated in malaria due to P. ovale.
Topics: Aminoquinolines; Antimalarials; Humans; Liver; Malaria; Parasitemia; Plasmodium; Plasmodium falciparum; Plasmodium knowlesi; Plasmodium malariae; Plasmodium ovale; Plasmodium vivax; Primaquine; Recurrence; Species Specificity
PubMed: 27079460
DOI: 10.1007/s00436-016-5043-0 -
British Journal of Clinical Pharmacology Jun 2022Methaemoglobin results from the oxidation of ferrous to ferric iron in the centre of the haem moiety of haemoglobin. The production of dose-dependent methaemoglobinaemia... (Review)
Review
Methaemoglobin results from the oxidation of ferrous to ferric iron in the centre of the haem moiety of haemoglobin. The production of dose-dependent methaemoglobinaemia by 8-aminoquinoline antimalarial drugs appears to be associated with, but is not directly linked to, therapeutic efficacy against latent Plasmodium vivax and Plasmodium ovale malarias (radical cure). Iatrogenic methaemoglobinaemia may be a useful pharmacodynamic measure in 8-aminoquinoline drug and dose optimization.
Topics: Aminoquinolines; Antimalarials; Humans; Methemoglobinemia; Plasmodium vivax
PubMed: 34997616
DOI: 10.1111/bcp.15219