preprint · medRxiv
Malaria control in sub-Saharan Africa primarily concentrates on Plasmodium falciparum, but non-falciparum parasites such as Plasmodium ovale curtisi and Plasmodium ovale wallikeri are increasingly prevalent. An assessment of over seven thousand asymptomatic participants in coastal Tanzania between 2018 and 2022 tracked infections using sensitive molecular assays. While Plasmodium falciparum predominated, Plasmodium ovale occurred in more than one in ten individuals. Unlike falciparum infections, ovale cases showed no link to recent rainfall, age, or sex. Notably, ovale infections were highest when falciparum numbers dropped, particularly during the long wet season where single ovale infections were common and co-infections were fewer than expected. This pattern shifted during the short rainy season, which had more co-infections. Furthermore, mixed infections containing both distinct ovale subspecies were common throughout the entire year.
Efforts to eliminate malaria have historically targeted the most lethal parasite species. Evidence that other malaria species persist, peak at different times of the year, and co-infect hosts alongside the main parasite highlights critical gaps in current public health strategies. Understanding these species dynamics is essential for designing treatments and interventions that prevent neglected malaria parasites from sustaining transmission.
This early-stage epidemiological research provides data relevant to diagnostic developers and public health bodies designing species-specific malaria tests and surveillance tools. While it indicates the need for diagnostic kits that capture non-falciparum species such as Plasmodium ovale, the abstract does not indicate an explicit commercialisation pathway or application pipeline.
AI-generated from the published abstract. Always read the original work before citing.
Abstract Background Malaria control in sub-Saharan Africa is typically focused on Plasmodium falciparum ( Pf ), but non-falciparum species like P. ovale curtisi ( Poc ) and P. ovale wallikeri ( Pow ) appear to be rising in prevalence, especially in East Africa. Methods We conducted polymerase chain reaction (PCR)-based screening of 7,173 asymptomatic individuals over 5 years of age in coastal Tanzania from 2018-2022, employing real-time 18S rRNA PCR assays for P. falciparum and P. ovale , followed by Poc / Pow detection. Plasmodium positivity was compared across seasons and demographic groups, and interactions between species were analyzed via binomial regression. Results Pf infection (prevalence 27.4%) was associated with younger age, male sex, and higher recent cumulative rainfall, whereas these associations were not apparent for P. ovale ( Po , prevalence 11.5%). Po infections appeared to peak during months with lower Pf prevalence, especially during the long wet season, when Po mono-infections predominated and fewer Pf - Po co-infections were detected than expected by independent assortment. This apparent antagonism was reversed during the short wet season: Pf - Po co-infections were comparatively enriched despite low overall Po prevalence. In contrast, excess mixed Poc / Pow infections were detected across all seasons, composing 23% of the Po -positive isolates in which a specific Po species could be detected. Conclusions The epidemiology of P. ovale species in coastal Tanzania suggests they are frequently present when P. falciparum recedes, but also co-infect the same hosts during the short wet season. Meanwhile, the individual Poc and Pow species often co-exist within individuals, perhaps due to co-transmission or concurrent relapse.
This page summarises published work. The authoritative version sits with the publisher.
DOI: 10.1101/2025.03.12.25323778
Is something wrong with this record? Report it or request removal.
Discussion
Have you built on this work, tried to replicate it, or seen it applied in practice? Share what you know. Verified researchers and MARATTO™ domain experts can open a discussion, and any member can reply. Contributions are reviewed before they appear.
No discussion yet. Open the first thread.
New to MARATTO™? Create a free account.
