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Frontiers in Public Health 2023This study aimed at exploring the epidemiological pattern of imported malaria in China before malaria elimination in 2021, to provide evidence-based data for preventing...
BACKGROUND
This study aimed at exploring the epidemiological pattern of imported malaria in China before malaria elimination in 2021, to provide evidence-based data for preventing malaria re-establishment in China.
METHODS
Nine-year surveillance data on imported malaria in four provincial-level administrative divisions (PLADs) (Anhui, Chongqing, Guangxi, and Zhejiang) between 2011 and 2019 were thoroughly collected and analyzed.
RESULTS
A quite stable trend in imported malaria cases between 2011 and 2019 was observed. In total, 6,064 imported patients were included. was the most frequently reported species (4,575, 75.6%). Cases of malaria were most frequently imported from Western Africa (54.4%). We identified an increasing trend in and a persistence of infections among the cases of malaria imported from Western Africa. Most patients (97.5%) were 20-50 years old. Among imported malaria infections, the main purposes for traveling abroad were labor export (4,914/6,064, 81.0%) and business trips (649, 10.7%). Most patients (2,008/6,064, 33.1%) first visited county-level medical institutions when they sought medical help in China. More patients were diagnosed within 3 days after visiting Centers for Disease Control and Prevention (CDCs) or entry-exit quarantine facilities (EQFs) (1,147/1609, 71.3%) than after visiting medical institutions (2,182/3993, 54.6%).
CONCLUSION
Imported malaria still poses a threat to the malaria-free status of China. County-level institutions are the primary targets in China to improve the sensitivity of the surveillance system and prevent the re-establishment of malaria. Health education should focus on exported labors, especially to Western and Central Africa. Increasing trend in and persistence of infections indicated their underestimations in Western Africa. Efficient diagnostic tools and sensitive monitoring systems are required to identify species in Africa.
Topics: Humans; Young Adult; Adult; Middle Aged; Plasmodium ovale; Plasmodium vivax; Incidence; China; Malaria
PubMed: 37448654
DOI: 10.3389/fpubh.2023.1203095 -
Malaria Journal Jul 2023The global battle against malaria is facing formidable challenges, particularly in controlling Plasmodium vivax and Plasmodium ovale, whose cases have not been reduced...
BACKGROUND
The global battle against malaria is facing formidable challenges, particularly in controlling Plasmodium vivax and Plasmodium ovale, whose cases have not been reduced as effectively as Plasmodium falciparum because of their relapse. This study investigates the current situation and underlying factors contributing to relapse or recrudescence of imported cases of P. vivax and P. ovale, and seeks to provide a reference for reducing relapse or recrudescence in malaria-free areas and offers a scientific basis for designing strategies to prevent imported re-transmission.
METHODS
This study analysed imported P. vivax and P. ovale in Anhui, Zhejiang, Henan, Hubei, and Guangxi provinces during 2014-2021 by retrospective analysis. A case-control study was conducted on patients who experienced relapse or recrudescence.
RESULTS
From 2014 to 2021, 306 cases of P.vivax and 896 cases of P.ovale were included in the study, while 75 cases had relapse or recrudescence, including 49 cases of P. ovale (65.33%) and 26 cases of P. vivax (34.67%). Within less than 5 weeks after returning to the country, 122 cases of P. vivax (39.87%, 122/306) and 265 cases of P. ovale (29.58%, 265/896) occurred. Within less than 53 weeks, the ratio of P. vivax was 94.77% (290/306), and that of P. ovale was 89.96% (806/896). Among the cases experiencing relapse or recrudescence, only 1 case of P. vivax (1/26 3.85%) and 3 cases of P. ovale (3/49 6.12%) occurred within less than 5 weeks after the first onset, whereas 21 cases of P. vivax (21/26 80.77%) and 42 cases of P. ovale (42/49 85.71%) occurred within less than 53 weeks after the first onset. The difference in relapse or recrudescence due to different drugs and medication regimens and medical activities at various levels of medical institutions was statistically significant.
CONCLUSION
In areas where malaria has been eliminated, routine health screening in a scientific time frame for people returning from at-risk areas can effectively improve the efficiency of preventing re-transmission, thereby reducing prevention costs and disease burden. Preventing patients from self-treating and strengthening medication regulations in health facilities are key measures to reduce relapse or recrudescence.
Topics: Humans; Plasmodium vivax; Plasmodium ovale; Case-Control Studies; Retrospective Studies; China; Malaria; Malaria, Vivax; Recurrence; Chronic Disease
PubMed: 37443070
DOI: 10.1186/s12936-023-04642-y -
Oman Medical Journal May 2023Despite a significant reduction in the global case incidence and mortality of malaria in the past 20 years, malaria continues to wreak havoc on people's health across... (Review)
Review
OBJECTIVES
Despite a significant reduction in the global case incidence and mortality of malaria in the past 20 years, malaria continues to wreak havoc on people's health across the globe. Oman is a malaria-free country, meeting the World Health Organization's (WHO) criteria, having no indigenous malaria case documented since 2010, and maintaining that status for three consecutive years. Oman has a national strategy for prevention of re-establishment of malaria and to maintain their malaria-free status. In this paper, we explore Oman's malaria elimination progress and provide recommendations for accelerating and sustaining malaria free status using WHO malaria elimination strategies.
METHODS
Secondary data from the years 1976 to 2020 was extracted from official sources utilized to assess progress. A review and epidemiological analysis of malaria cases, species classification, and source of infection was conducted. The data and situation were compared to WHO malaria elimination pillars.
RESULTS
The number of malaria cases reported from 1976 to 2020 was 298 070, a decline from 1.6 to 0.1 per 1000 population. Of the 4415 cases reported between 1994-2004, 98.0% were classified as imported and 73.0% of people diagnosed with malaria were 20-34 years old. The number of autochthonous cases began to decline in 1994 from a high of 4415 cases (3.6 per 1000 population) to zero by 2004 with no deaths attributed to autochthonous malaria cases after the year 2000. By 2020, accounted for 86.0% of cases, cases declined to 9.0% and and comprised the remaining 6.0% of case notifications.
CONCLUSIONS
Oman achieved malaria elimination status in 2013. To maintain this status, it is essential to adopt a national prevention strategy of re-establishment of malaria and maintain malaria-free status targets.
PubMed: 37441673
DOI: 10.5001/omj.2023.50 -
The Journal of Infectious Diseases Oct 2023Like Plasmodium vivax, both Plasmodium ovale curtisi and Plasmodium ovale wallikeri have the ability to cause relapse in humans, defined as recurring asexual parasitemia...
Like Plasmodium vivax, both Plasmodium ovale curtisi and Plasmodium ovale wallikeri have the ability to cause relapse in humans, defined as recurring asexual parasitemia originating from liver-dormant forms subsequent to a primary infection. Here, we investigated relapse patterns in P ovale wallikeri infections from a cohort of travelers who were exposed to the parasite in sub-Saharan Africa and then experienced relapses after their return to France. Using a novel set of 8 highly polymorphic microsatellite markers, we genotyped 15 P ovale wallikeri relapses. For most relapses, the paired primary and relapse infections were highly genetically related (with 12 being homologous), an observation that was confirmed by whole-genome sequencing for the 4 relapses we further studied. This is, to our knowledge, the first genetic evidence of relapses in P ovale spp.
Topics: Humans; Plasmodium ovale; Malaria; Plasmodium vivax; Recurrence; Microsatellite Repeats
PubMed: 37329228
DOI: 10.1093/infdis/jiad216 -
Annals of Medicine Dec 2023Microscopy was used to characterize platelet--infected erythrocyte interactions in patients infected with , , or , and to investigate the relationship between...
OBJECTIVE
Microscopy was used to characterize platelet--infected erythrocyte interactions in patients infected with , , or , and to investigate the relationship between platelet-associated parasite killing and parasite clearance.
METHODS
Data from 244 malaria patients admitted to the Fourth People's Hospital of Nanning between 1 January 2011 and 30 September 2022, and 45 healthy controls, were collected prospectively and assessed retrospectively. Characteristics of platelet-erythrocyte interactions were visualized by microscopy, and blood cell count and clinical profiles of these participants were obtained from the electronic medical records. ANOVA, contingency tables and Cox proportional hazards regression models were used to do statistical analysis on the subgroups.
RESULTS
Platelet enlargement and minor pseudopodia development were observed. Platelets were found directly attaching to parasitized erythrocytes by all species studied, especially mature stages, and lysis of parasitized erythrocytes was connected to platelet-mediated cytolysis. Platelet counts were correlated inversely with parasitaemia and duration of parasite clearance. Artemisinin combination therapy was more effective than artemisinin alone in clearing in patients with thrombocytopenia.
CONCLUSIONS
Platelet-parasitized erythrocytes cell-to-cell contacts initiated platelet-associated parasite killing and helped to limit infection in cases of human malaria. The weakening platelet-associated parasite killing effects could be counteracted by artemisinin combination therapy in patients with thrombocytopenia.
Topics: Humans; Animals; Blood Platelets; Parasites; Retrospective Studies; Malaria; Thrombocytopenia; Artemisinins
PubMed: 37310126
DOI: 10.1080/07853890.2023.2221453 -
The American Journal of Tropical... Aug 2023Malaria remains a major public health challenge that needs attention, especially when the world is aiming at malaria elimination in the near future. It is crucial to...
Malaria remains a major public health challenge that needs attention, especially when the world is aiming at malaria elimination in the near future. It is crucial to understand the underlying genetic factors and epigenetics involved in malaria susceptibility and the dynamics of host immune responses that affect disease outcomes and relapses in Plasmodium vivax and Plasmodium ovale. Studies in newborn and adult twins can help in understanding the comparative roles of environmental and genetic factors on disease pathogenesis and outcome. These studies can help in providing insights into the factors responsible for malaria susceptibility, clinical presentation, responsiveness toward existing as well as candidate antimalarials, and even identification of novel therapeutic targets. The results and outcomes from twin studies can be further applied to the entire population. In the present manuscript, we analyze the available literature on malaria and human twins and discuss the significance and benefits of twin studies to help in better understanding malaria.
Topics: Adult; Infant, Newborn; Humans; Malaria; Antimalarials; Plasmodium vivax; Plasmodium ovale; Genetic Linkage; Malaria, Vivax
PubMed: 37277110
DOI: 10.4269/ajtmh.23-0028 -
Journal of Public Health in Africa Mar 2023In Gabon, malaria remains a major public health problem. All malaria cases with axillary temperature ≥ 37.5°C with a parasites density ≥ 1200/μL are serious cases...
BACKGROUND
In Gabon, malaria remains a major public health problem. All malaria cases with axillary temperature ≥ 37.5°C with a parasites density ≥ 1200/μL are serious cases and must be treated as a medical emergency. Thus, early diagnosis is essential for successful treatment. Because of the impact of malaria on the population, the surveillance of malaria infections in hospitals is urgently needed. The aim of this study was to to assess of clinical cases of malaria in a private health structure in Franceville between 2017 and 2019.
METHODS
For that, we conducted a retrospective study using data on malaria cases recorded in a private medical analysis laboratory in Franceville, southeast Gabon. Malaria was diagnosed in this laboratory using a Rapid Diagnostic Test and confirmed by microscopic analysis.
RESULTS
Analysis of 2518 patient forms revealed an increase in malaria prevalence in Franceville between 2017-2019. The global clinical cases was 26.1% (658/2015). Children under 5 years (44.0%) and patients aged 5-14 years (40.1%) were more affected than patients aged ≥15 years (18.8%, P=0.0001). Malaria infection was also significantly dependent on season and gender. We observed at least three Plasmodium species and the predominant Plasmodium species was 80.0%, followed by (19.5%) and (17.8%).
CONCLUSION
Our study showed that malaria remains a public health priority for the population of Franceville and that the prevalence of clinical cases of malaria at the laboratory decrease between 2017 and 2019. Our results highlight the need for strategies to control malaria in Franceville, adapted to epidemiological contexts and environmental constraint.
PubMed: 37229438
DOI: 10.4081/jphia.2023.1865 -
Emerging Infectious Diseases Jun 2023Achieving malaria elimination requires considering both Plasmodium falciparum and non-P. falciparum infections. We determined prevalence and geographic distribution of 4...
Achieving malaria elimination requires considering both Plasmodium falciparum and non-P. falciparum infections. We determined prevalence and geographic distribution of 4 Plasmodium spp. by performing PCR on dried blood spots collected within 8 regions of Tanzania during 2017. Among 3,456 schoolchildren, 22% had P. falciparum, 24% had P. ovale spp., 4% had P. malariae, and 0.3% had P. vivax infections. Most (91%) schoolchildren with P. ovale infections had low parasite densities; 64% of P. ovale infections were single-species infections, and 35% of those were detected in low malaria endemic regions. P. malariae infections were predominantly (73%) co-infections with P. falciparum. P. vivax was detected mostly in northern and eastern regions. Co-infections with >1 non-P. falciparum species occurred in 43% of P. falciparum infections. A high prevalence of P. ovale infections exists among schoolchildren in Tanzania, underscoring the need for detection and treatment strategies that target non-P. falciparum species.
Topics: Humans; Child; Plasmodium falciparum; Prevalence; Tanzania; Coinfection; Plasmodium malariae; Malaria; Malaria, Falciparum; Malaria, Vivax
PubMed: 37209670
DOI: 10.3201/eid2906.221016