The phenomenon of relapsing malaria has been recognised for centuries. It is caused in humans by the parasite species Plasmodium vivax and Plasmodium ovale, which can arrest growth at an early, asymptomatic stage as hypnozoites inside liver cells. These dormant parasites can remain quiescent for months or years, then reactivate causing symptomatic malaria.
Plasmodial transketolase (PTKT) enzyme is one of the novel pharmacological targets being explored as potential anti-malarial drug target due to its functional role and low sequence identity to the human enzyme. Despite this, features contributing to such have not been exploited for anti-malarial drug design. Additionally, there are no anti-malarial drugs targeting PTKTs whereas the broad activity of these inhibitors against PTKTs from other Plasmodium spp. is yet to be reported. This study characterises different PTKTs [Plasmodium falciparum (PfTKT), Plasmodium vivax (PvTKT), Plasmodium ovale (PoTKT), Plasmodium malariae (PmTKT) and Plasmodium knowlesi (PkTKT) and the human homolog (HsTKT)] to identify key sequence and structural based differences as well as the identification of selective potential inhibitors against PTKTs.
Imported malaria is a major challenge for countries that are in malaria elimination stage such as Zambia. Legitimate cross-border activities add to the risk of transmission, necessitating determination of prevalence, characteristics and risk factors of imported and local malaria.
Plasmodium vivax (P vivax) is a focus of malaria elimination. It is important because P vivax and Plasmodium falciparum infection are co‐endemic in some areas. There are asymptomatic carriers of P vivax, and the treatment for P vivax and Plasmodium ovale malaria differs from that used in other types of malaria. Rapid diagnostic tests (RDTs) will help distinguish P vivax from other malaria species to help treatment and elimination. There are RDTs available that detect P vivax parasitaemia through the detection of P vivax‐specific lactate dehydrogenase (LDH) antigens.
A thorough understanding of malaria vector species composition and their bionomic characteristics is crucial to devise effective and efficient vector control interventions to reduce malaria transmission. It has been well documented in Africa that malaria interventions in the past decade have resulted in major changes in species composition from endophilic Anopheles gambiae to exophilic An. arabiensis.
Asymptomatic carriers of Plasmodium parasites hamper malaria control and eradication. Achieving malaria eradication requires ultrasensitive diagnostics for low parasite density infections (<100 parasites per microliter blood) that work in resource-limited settings (RLS). Sensitive point-of-care diagnostics are also lacking for nonfalciparum malaria, which is characterized by lower density infections and may require additional therapy for radical cure.
Plasmodium ovale is an understudied malaria species prevalent throughout much of sub-Saharan Africa. Little is known about the distribution of ovale malaria and risk factors associated with infection in areas of high malaria endemicity.
We report two cases of malaria diagnosed in Rhode Island. First, a 21-year-old female who presented with 5 days of fevers, chills, headache, and myalgias after returning from a trip to Liberia, found to have uncomplicated malaria due to P. ovale which was treated successfully with atovaquone/proguanil and primaquine.
In clinical practice, mixed-species malaria infections are often not detected by light microscopy (LM) or rapid diagnostic test, as a low number of parasites of one species may occur. Here, we report the case of an 8-year-old girl migrating with her family from Afghanistan with a two-species mixed infection with Plasmodium vivax and Plasmodium ovale.