-
Acta Medica Indonesiana Jan 2023Plasmodium ovale consists of two subspecies - P. ovale wallikeri and P. ovale curtisi. Increased reports of imported malaria ovale in non-endemic regions and mixed...
Plasmodium ovale consists of two subspecies - P. ovale wallikeri and P. ovale curtisi. Increased reports of imported malaria ovale in non-endemic regions and mixed infection of P. ovale with other Plasmodium species suggest that P. ovale might be under-detected during routine surveillance. Areas endemic with P. ovale have mostly been reported in African and Western Pacific countries. A recent case report in Indonesia indicated that regions with P. ovale endemicity are not only distributed in Lesser Sunda and Papua, but also in North Sumatra.
Topics: Humans; Plasmodium ovale; Indonesia; Malaria; Coinfection
PubMed: 36999258
DOI: No ID Found -
Microbiology Spectrum Oct 2022Since 2010, the human-infecting malaria parasite Plasmodium ovale spp. has been divided into two genetically distinct species, P. ovale wallikeri and P. ovale curtisi....
Since 2010, the human-infecting malaria parasite Plasmodium ovale spp. has been divided into two genetically distinct species, P. ovale wallikeri and P. ovale curtisi. In recent years, application of whole-genome sequencing (WGS) to spp. allowed to get a better understanding of its evolutionary history and discover some specific genetic patterns. Nevertheless, WGS data from spp. are still scarce due to several drawbacks, including a high level of human DNA contamination in blood samples, infections with commonly low parasite density, and the lack of robust culture. Here, we developed two selective whole-genome amplification (sWGA) protocols that were tested on six and five mono-infection clinical samples. Blood leukodepletion by a cellulose-based filtration was used as the gold standard for intraspecies comparative genomics with sWGA. We also demonstrated the importance of genomic DNA preincubation with the endonuclease McrBC to optimize spp. sWGA. We obtained high-quality WGS data with more than 80% of the genome covered by ≥5 reads for each sample and identified more than 5,000 unique single-nucleotide polymorphisms (SNPs) per species. We also identified some amino acid changes in and for which similar mutations in P. falciparum and P. vivax are associated with pyrimethamine or cycloguanil resistance. In conclusion, we developed two sWGA protocols for spp. WGS that will help to design much-needed large-scale spp. population studies. Plasmodium ovale spp. has the ability to cause relapse, defined as recurring asexual parasitemia originating from liver-dormant forms. Whole-genome sequencing (WGS) data are of importance to identify putative molecular markers associated with relapse or other virulence mechanisms. Due to low parasitemia encountered in spp. infections and no culture available, WGS of spp. is challenging. Blood leukodepletion by filtration has been used, but no technique exists yet to increase the quantity of parasite DNA over human DNA when starting from genomic DNA extracted from whole blood. Here, we demonstrated that selective whole-genome amplification (sWGA) is an easy-to-use protocol to obtain high-quality WGS data for both spp. species from unprocessed blood samples. The new method will facilitate spp. population genomic studies.
Topics: Humans; Plasmodium ovale; Parasitemia; Pyrimethamine; Malaria; Recurrence; Amino Acids; Endonucleases
PubMed: 36098524
DOI: 10.1128/spectrum.00726-22 -
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 -
Journal of Clinical Microbiology Dec 2004There have been reports of increasing numbers of cases of malaria among migrants and travelers. Although microscopic examination of blood smears remains the "gold... (Comparative Study)
Comparative Study
There have been reports of increasing numbers of cases of malaria among migrants and travelers. Although microscopic examination of blood smears remains the "gold standard" in diagnosis, this method suffers from insufficient sensitivity and requires considerable expertise. To improve diagnosis, a multiplex real-time PCR was developed. One set of generic primers targeting a highly conserved region of the 18S rRNA gene of the genus Plasmodium was designed; the primer set was polymorphic enough internally to design four species-specific probes for P. falciparum, P. vivax, P. malarie, and P. ovale. Real-time PCR with species-specific probes detected one plasmid copy of P. falciparum, P. vivax, P. malariae, and P. ovale specifically. The same sensitivity was achieved for all species with real-time PCR with the 18S screening probe. Ninety-seven blood samples were investigated. For 66 of them (60 patients), microscopy and real-time PCR results were compared and had a crude agreement of 86% for the detection of plasmodia. Discordant results were reevaluated with clinical, molecular, and sequencing data to resolve them. All nine discordances between 18S screening PCR and microscopy were resolved in favor of the molecular method, as were eight of nine discordances at the species level for the species-specific PCR among the 31 samples positive by both methods. The other 31 blood samples were tested to monitor the antimalaria treatment in seven patients. The number of parasites measured by real-time PCR fell rapidly for six out of seven patients in parallel to parasitemia determined microscopically. This suggests a role of quantitative PCR for the monitoring of patients receiving antimalaria therapy.
Topics: Animals; DNA, Protozoan; Humans; Malaria; Plasmodium; Plasmodium falciparum; Plasmodium malariae; Plasmodium ovale; Plasmodium vivax; Polymerase Chain Reaction; RNA, Ribosomal, 18S; Sensitivity and Specificity; Species Specificity
PubMed: 15583293
DOI: 10.1128/JCM.42.12.5636-5643.2004 -
Malaria Journal Sep 2013In Ethiopia Plasmodium falciparum and Plasmodium vivax are the dominant species accounting for roughly 60 and 40% of malaria cases, respectively. Recently a major shift...
BACKGROUND
In Ethiopia Plasmodium falciparum and Plasmodium vivax are the dominant species accounting for roughly 60 and 40% of malaria cases, respectively. Recently a major shift from P. falciparum to P. vivax has been observed in various parts of the country but the epidemiology of the other human malaria species, Plasmodium ovale spp. and Plasmodium malariae remains poorly understood. The aim of this study was to assess P. ovale curtisi and wallikeri infection in north-west Ethiopia by using microscopy and nested PCR.
METHODS
A health institution-based survey using non-probability sampling techniques was conducted at Maksegnet, Enfranze and Kola Diba health centres and Metema hospital in North Gondar. Three-hundred patients with signs and symptoms consistent with malaria were included in this study and capillary blood was collected for microscopic examination and molecular analysis of Plasmodium species. Samples were collected on Whatman 903 filter papers, stored in small plastic bags with desiccant and transported to Vienna (Austria) for molecular analysis. Data from study participants were entered and analysed by SPSS 20 software.
RESULTS
Out of 300 study participants (167 males and 133 females), 184 samples were classified positive for malaria (133 P. falciparum and 51 P. vivax) by microscopy. By species-specific PCR 233 Plasmodium spp (95% CI: 72.6-82) were detected and the majority 155 (66.5%, 95% CI: 60.2-72.3) were P. falciparum followed by P. vivax 69 (29.6%, 95% CI; 24.1-35.8) and 9 (3.9%, 95% CI: 2-7.2) samples were positive for P. ovale. Seven of P. ovale parasites were confirmed as P. ovale wallikeri and two were confirmed as P. ovale curtisi. None of the samples tested positive for P. malariae. During microscopic examination there were high (16.3%) false negative reports and all mixed infections and P. ovale cases were missed or misclassified.
CONCLUSION
This study indicates that P. ovale malaria is under-reported in Ethiopia and provides the first known evidence of the sympatric distribution of indigenous P. ovale wallikeri and P. ovale curtisi in Ethiopia. Therefore, further studies assessing the prevalence of the rare species P. ovale and P. malariae are urgently needed to better understand the species distribution and to adapt malaria control strategies.
Topics: Adolescent; Adult; DNA, Protozoan; Ethiopia; Female; Humans; Malaria; Male; Microscopy; Molecular Sequence Data; Plasmodium ovale; Polymerase Chain Reaction; Prevalence; Sequence Analysis, DNA; Young Adult
PubMed: 24073668
DOI: 10.1186/1475-2875-12-346 -
The American Journal of Tropical... Dec 2014Splenic infarction is a rare complication of malaria. We report two recent cases of splenic infarction after Plasmodium vivax infection. No systematic review of...
Splenic infarction is a rare complication of malaria. We report two recent cases of splenic infarction after Plasmodium vivax infection. No systematic review of malaria-induced splenic infarction was available, therefore we conducted a systematic review of the English, French, and Spanish literature in PubMed and KoreaMed for reports of malaria-associated splenic infarction from 1960 to 2012. Of the 40 cases collected on splenic infarction by Plasmodium species, 23 involved P. vivax, 11 Plasmodium falciparum, one Plasmodium ovale, and five a mixed infection of P. vivax and P. falciparum. Of the 40 cases, 2 (5.0%) involved splenectomy and 5 (12.5%) were accompanied by splenic rupture. The median time from symptom onset to diagnosis was 8.5 days (range, 3-90 days). Improved findings after treatment were observed in 8 (88.9%) of 9 patients with splenic infarction on follow-up by computed tomography or ultrasonography. All patients survived after treatment with the exception of one patient with cerebral malaria. Clinicians should consider the possibility of splenic infarction when malaria-infected patients have left upper quadrant pain.
Topics: Adult; Female; Humans; Malaria; Male; Middle Aged; Splenic Infarction; Tomography, X-Ray Computed
PubMed: 25294615
DOI: 10.4269/ajtmh.14-0190 -
Microorganisms Jun 2022was until recently thought to be a single unique species. However, the deployment of more sensitive tools has led to increased diagnostic sensitivity, including new...
was until recently thought to be a single unique species. However, the deployment of more sensitive tools has led to increased diagnostic sensitivity, including new evidence supporting the presence of two sympatric species: (Poc) and (Pow). The increased reports and evolution of subspecies are concerning for sub-Saharan Africa where the greatest burden of malaria is borne. Employing published sequence data, we set out to decipher the genetic diversity and phylogenetic relatedness of and using the tryptophan-rich protein and small subunit ribosomal RNA genes from Gabon, Senegal, Ethiopia and Kenya. Higher number of segregating sites were recorded in Poc isolates from Gabon than from Ethiopia, with a similar trend in the number of haplotypes. With regards to Pow, the number of segregating sites and haplotypes from Ethiopia were higher than from those in Gabon. Poc from Kenya, had higher segregating sites (20), and haplotypes (4) than isolates from Senegal (8 and 3 respectively), while nucleotide from Senegal were more diverse (θw = 0.02159; π = 0.02159) than those from Kenya (θw = 0.01452; π = 0.01583). Phylogenetic tree construction reveal two large clades with Poc from Gabon and Ethiopia, and distinct Gabonese and Ethiopian clades on opposite ends. A similar observation was recorded for the phylogeny of Poc isolates from Kenya and Senegal. With such results, there is a high potential that ovale malaria control measures deployed in one country may be effective in the other since parasite from both countries show some degree of relatedness. How this translates to malaria control efforts throughout the continent would be next step deserving more studies.
PubMed: 35744665
DOI: 10.3390/microorganisms10061147 -
Acta Medica Portuguesa Jun 2022Malaria is a major cause of suffering, disease, and death worldwide and is considered the most important of all human parasitic diseases. Malaria is still endemic in...
Malaria is a major cause of suffering, disease, and death worldwide and is considered the most important of all human parasitic diseases. Malaria is still endemic in most tropical and sub-tropical areas and globalization has contributed to an increase of imported cases around the world. We report a Plasmodium ovale infection in a traveler with recent return from a long land trip across West Africa. He declared adherence to mefloquine chemoprophylaxis only at the start of the trip. Initially, he was seen at two different hospitals and in both he was screened for malaria by microscopy and rapid diagnostic test, but his diagnosis was not confirmed. The traveler was then diagnosed at our hospital with a malaria infection by Plasmodium ovale. Complete blood count showed mild anemia, but leukocytes and platelets were already normal. Symptoms resolved in 24 hours after treatment started. Microscopy of stained blood films remains the gold standard for malaria diagnosis, which is critically dependent on trained eyes. In non-endemic regions with few cases during the year, training programs in malaria microscopy are crucial. The aim is to prevent the reintroduction of malaria in Europe, reduce individual morbidity and suffering, and thus contribute towards reduction in deaths caused by this disease.
Topics: Male; Humans; Plasmodium ovale; Antimalarials; Mefloquine; Travel; Malaria
PubMed: 33979568
DOI: 10.20344/amp.15814 -
International Journal For Parasitology May 2011It has been proposed that ovale malaria in humans is caused by two closely related but distinct species of malaria parasite, Plasmodium ovale curtisi and Plasmodium...
It has been proposed that ovale malaria in humans is caused by two closely related but distinct species of malaria parasite, Plasmodium ovale curtisi and Plasmodium ovale wallikeri. It was recently shown that these two parasite types are sympatric at the country level. However, it remains possible that localised geographic, temporal or ecological barriers exist within endemic countries which prevent recombination between the genomes of the two species. Here, using conventional and real-time quantitative PCR (qPCR) methods specifically designed to discriminate P. o. curtisi and P. o. wallikeri, it is shown that both species are present among clinic attendees in Congo-Brazzaville, and occur simultaneously both in lake-side and inland districts in Uganda and on Bioko Island, Equatorial Guinea. Thus P. o. curtisi and P. o. wallikeri in these localities are exactly sympatric in both time and space. These findings are consistent with the existence of a biological barrier, rather than geographical or ecological factors, preventing recombination between P. o. curtisi and P. o. wallikeri. In cross-sectional surveys carried out in Uganda and Bioko, our results show that infections with P. ovale spp. are more common than previously thought, occurring at a frequency of 1-6% in population samples, with both proposed species contributing to ovale malaria in six sites. Malaria elimination programmes in Africa need to include strategies for control of P. o. curtisi and P. o. wallikeri.
Topics: Animals; Congo; DNA, Protozoan; Guinea; Humans; Malaria; Molecular Sequence Data; Phylogeography; Plasmodium ovale; Protozoan Proteins; Sequence Analysis, DNA; Uganda
PubMed: 21315074
DOI: 10.1016/j.ijpara.2011.01.004