Is the Epidemiology of Plasmodium knowlesi Changing, and What Does This Mean for Malaria Control in Southeast Asia?

2019 ◽  
Author(s):  
Harin Karunajeewa ◽  
Jonathan Berman
Keyword(s):  
Southeast Asia ◽  
Malaria Control ◽  
Plasmodium Knowlesi

scholarly journals Deploying triple artemisinin-based combination therapy (TACT) for malaria treatment in Africa: ethical and practical considerations

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Paulina Tindana ◽  
Freek de Haan ◽  
Chanaki Amaratunga ◽  
Mehul Dhorda ◽  
Rob W. van der Pluijm ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Combination Therapy ◽  
Southeast Asia ◽  
Malaria Control ◽  
Lessons Learned ◽  
Line Treatment ◽  
African Continent ◽  
First Line ◽  
First Line Treatment ◽  
Made In

AbstractMalaria remains a major cause of morbidity and mortality in Africa, particularly in children under five years of age. Availability of effective anti-malarial drug treatment is a cornerstone for malaria control and eventual malaria elimination. Artemisinin-based combination therapy (ACT) is worldwide the first-line treatment for uncomplicated falciparum malaria, but the ACT drugs are starting to fail in Southeast Asia because of drug resistance. Resistance to artemisinins and their partner drugs could spread from Southeast Asia to Africa or emerge locally, jeopardizing the progress made in malaria control with the increasing deployment of ACT in Africa. The development of triple artemisinin-based combination therapy (TACT) could contribute to mitigating the risks of artemisinin and partner drug resistance on the African continent. However, there are pertinent ethical and practical issues that ought to be taken into consideration. In this paper, the most important ethical tensions, some implementation practicalities and preliminary thoughts on addressing them are discussed. The discussion draws upon data from randomized clinical studies using TACT combined with ethical principles, published literature and lessons learned from the introduction of artemisinin-based combinations in African markets.

Acquired clinical immunity to malaria in non-human primates co-infected with Schistosoma and Plasmodium parasites

2021 ◽  
Author(s):  
Ruth K. Nyakundi ◽  
Jann Hau ◽  
Paul Ogongo ◽  
Onkoba Nyamongo ◽  
Maamum Jeneby ◽  
...  
Keyword(s):  
T Cells ◽  
Malaria Control ◽  
Malaria Infection ◽  
Memory T Cells ◽  
Clinical Symptoms ◽  
Plasmodium Knowlesi ◽  
Acquired Immunity ◽  
Control Group ◽  
Chronic Infections ◽  
Long Term Impact

Background. Naturally acquired immunity to malaria develops over several years and can be compromised by concomitant infections. This study explored the influence of chronic schistosomiasis on clinical outcome and immunity to repeated malaria infection. Methods. Two groups of baboons (n=8 each), were infected with Schistosoma mansoni cercariae to establish chronic infections. One of the two groups was treated with Praziquantel to eliminate schistosome infection. The two groups plus a new malaria control group (n=8), were inoculated three times with Plasmodium knowlesi parasites at one-month intervals. Clinical data, IgG, IgG1, memory T-cells and monocyte levels were recorded. Results. We observed after three P. knowlesi infections; i) reduced clinical symptoms in all groups with each subsequent infection, ii) increase IgG and IgG1in the malaria control (Pk-only) group iii) increased IgG and IgG1, CD14 + and CD14 - CD16 + in the Schistosoma treated (Schisto/PZQ+Pk) group and iv) significantly lower IgG and IgG1 levels compared to Pk-only, reduced CD4 + CD45RO + and increased CD14 - CD16 + cells in the co-infected (Schisto+Pk) group. Conclusion. Chronic S. mansoni does not compromise establishment of clinical immunity after multiple malaria infections with non-classical monocytes seeming to play a role. Failure to develop robust antibody and memory T-cells may have a long-term impact on acquired immunity to malaria infection.

scholarly journals Plasmodium knowlesi Malaria in Sabah, Malaysia, 2015–2017: Ongoing Increase in Incidence Despite Near-elimination of the Human-only Plasmodium Species

2019 ◽  
Vol 70 (3) ◽  
pp. 361-367 ◽  
Author(s):  
Daniel J Cooper ◽  
Giri S Rajahram ◽  
Timothy William ◽  
Jenarun Jelip ◽  
Rashidah Mohammad ◽  
...  
Keyword(s):  
Malaria Control ◽  
Plasmodium Knowlesi ◽  
Plasmodium Species ◽  
Chain Reaction ◽  
Molecular Surveillance ◽  
Department Of Health ◽  
Zoonotic Malaria ◽  
Polymerase Chain ◽  
Prevention Activities ◽  
Notification Data

Abstract Background Malaysia aims to eliminate malaria by 2020. However, while cases of Plasmodium falciparum and Plasmodium vivax have decreased substantially, the incidence of zoonotic malaria from Plasmodium knowlesi continues to increase, presenting a major challenge to regional malaria control efforts. Here we report incidence of all Plasmodium species in Sabah, including zoonotic P. knowlesi, during 2015–2017. Methods Microscopy-based malaria notification data and polymerase chain reaction (PCR) results were obtained from the Sabah Department of Health and State Public Health Laboratory, respectively, from January 2015 to December 2017. From January 2016 this was complemented by a statewide prospective hospital surveillance study. Databases were matched, and species was determined by PCR, or microscopy if PCR was not available. Results A total of 3867 malaria cases were recorded between 2015 and 2017, with PCR performed in 93%. Using PCR results, and microscopy if PCR was unavailable, P. knowlesi accounted for 817 (80%), 677 (88%), and 2030 (98%) malaria cases in 2015, 2016, and 2017, respectively. P. falciparum accounted for 110 (11%), 45 (6%), and 23 (1%) cases and P. vivax accounted for 61 (6%), 17 (2%), and 8 (0.4%) cases, respectively. Of those with P. knowlesi, the median age was 35 (interquartile range: 24–47) years, and 85% were male. Conclusions Malaysia is approaching elimination of the human-only Plasmodium species. However, the ongoing increase in P. knowlesi incidence presents a major challenge to malaria control and warrants increased focus on knowlesi-specific prevention activities. Wider molecular surveillance in surrounding countries is required.

Challenges and prospects for dengue and malaria control in Thailand, Southeast Asia

2013 ◽  
Vol 29 (12) ◽  
pp. 623-633 ◽  
Author(s):  
Vincent Corbel ◽  
Francois Nosten ◽  
Kanutcharee Thanispong ◽  
Christine Luxemburger ◽  
Monthathip Kongmee ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Malaria Control

scholarly journals Limited Polymorphism of the Kelch Propeller Domain in Plasmodium malariae and P. ovale Isolates from Thailand

2016 ◽  
Vol 60 (7) ◽  
pp. 4055-4062 ◽  
Author(s):  
Supatchara Nakeesathit ◽  
Naowarat Saralamba ◽  
Sasithon Pukrittayakamee ◽  
Arjen Dondorp ◽  
Francois Nosten ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Southeast Asia ◽  
Severe Malaria ◽  
Malaria Control ◽  
Artemisinin Resistance ◽  
Plasmodium Malariae ◽  
The Other ◽  
Content Type ◽  
Functional Consequences ◽  
First Time

ABSTRACTArtemisinin resistance inPlasmodium falciparum, the agent of severe malaria, is currently a major obstacle to malaria control in Southeast Asia. A gene named “kelch13” has been associated with artemisinin resistance inP. falciparum. The orthologue of thekelchgene inP. vivaxwas identified and a small number of mutations were found in previous studies. Thekelchorthologues in the other two human malaria parasites,P. malariaeandP. ovale, have not yet been studied. Therefore, in this study, the orthologouskelchgenes ofP. malariae,P. ovale wallikeri, andP. ovale curtisiwere isolated and analyzed for the first time. The homologies of thekelchgenes ofP. malariaeandP. ovalewere 84.8% and 82.7%, respectively, compared to the gene inP. falciparum.kelchpolymorphisms were studied in 13P. malariaeand 5P. ovaleisolates from Thailand. There were 2 nonsynonymous mutations found in these samples. One mutation was P533L, which was found in 1 of 13P. malariaeisolates, and the other was K137R, found in 1 isolate ofP. ovale wallikeri(n= 4). This result needs to be considered in the context of widespread artemisinin used within the region; their functional consequences for artemisinin sensitivity inP. malariaeandP. ovalewill need to be elucidated.

scholarly journals First case of detection of Plasmodium knowlesi in Spain by Real Time PCR in a traveller from Southeast Asia

2010 ◽  
Vol 9 (1) ◽  
pp. 219 ◽  
Author(s):  
Thuy-Huong Ta Tang ◽  
Ana Salas ◽  
Marwa Ali-Tammam ◽  
Maria del Carmen Martinez ◽  
Marta Lanza ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Real Time ◽  
Real Time Pcr ◽  
Plasmodium Knowlesi ◽  
First Case

scholarly journals RISK FACTORS FOR PLASMODIUM KNOWLESI IN SOUTHEAST ASIA:A SYSTEMATIC REVIEW Authors

2020 ◽  
Vol 2 (2) ◽  
pp. 220-228
Keyword(s):  
Risk Factors ◽  
Systematic Review ◽  
Southeast Asia ◽  
Study Protocol ◽  
Plasmodium Knowlesi ◽  
Work Related ◽  
Zoonotic Malaria ◽  
Common Risk Factors ◽  
Behavioural Factors

Introduction: Plasmodium knowlesi zoonotic malaria has been identified in Borneo Malaysia in 2004, and has led to an increase in the number of cases throughout Southeast Asia. Many factors have contributed to increasing pattern. Therefore, this systematic review aims to identify risk factors for Plasmodium knowlesi infection that can aid in predicting and controlling the infection. Methods:Systematic search on articles related to risk factors of Plasmodium knowlesi infection was conducted using three databases namely PubMed, Scopus and Science direct. All the articles from year 2015 till May 2019 were selected. Results: A total of three articles were included in this review based on the study protocol. Three common risk factors for Plasmodium knowlesi infection was in identify mainly involved sociodemographic, work-related and behavioural factors. Conclusion: Risk factors for P. Knowlesi ranges not only from individual and community socidemographic background but also by environmental and geographical determinants. The inconsistency of the result was due to the variability and limitations of the studies itself. The research on P. Knowlesi, should be conducted with larger participants and longer length of follow up.

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