by Sunil Kumar Dogga, Jesse C. Rop, Alex Makunin, Fiona Teltscher, Damon-Lee Pointon, Ying Sims, Marcela Uliano-Silva, James Torrance, Thomas C. Mathers, Jonathan M. D. Wood, Sekou Sissoko, Antoine Dara, Dinkorma T. Ouologuem, Arthur M. Talman, Abdoulaye A. Djimdé, Mara K. N. Lawniczak Malaria, caused by mosquito-transmitted #Plasmodium parasites, remains a major global health challenge. While P. falciparum accounts for most malaria deaths, the lesser-studied P. ovale spp. and P. malariae also contribute to disease burden across many endemic regions, typically causing milder but chronic infections. Here, we generated high quality, chromosome-level reference genomes for P. ovale wallikeri, P. malariae, and P. falciparum directly from blood samples taken from natural infections. Using PacBio Ultra-Low-Input HiFi long-read sequencing and Hi-C chromatin conformation capture, we overcome limitations posed by low parasite biomass and the absence of in vitro culture for P. ovale wallikeri and P. malariae. These high quality reference genomes resolve previously inaccessible subtelomeric regions that include expanded gene families likely involved in host–parasite interactions, and they enhance our understanding of parasite persistence, transmission, immune evasion and comparative evolutionary studies. This work provides a critical foundation for including these neglected species in global malaria elimination efforts.

by Sunil Kumar Dogga, Jesse C. Rop, Alex Makunin, Fiona Teltscher, Damon-Lee Pointon, Ying Sims, Marcela Uliano-Silva, James Torrance, Thomas C. Mathers, Jonathan M. D. Wood, Sekou Sissoko, Antoine Dara, Dinkorma T. Ouologuem, Arthur M. Talman, Abdoulaye A. Djimdé, Mara K. N. Lawniczak Malaria, caused by mosquito-transmitted #Plasmodium parasites, remains a major global health challenge. While P. falciparum accounts for most malaria deaths, the lesser-studied P. ovale spp. and P. malariae also contribute to disease burden across many endemic regions, typically causing milder but chronic infections. Here, we generated high quality, chromosome-level reference genomes for P. ovale wallikeri, P. malariae, and P. falciparum directly from blood samples taken from natural infections. Using PacBio Ultra-Low-Input HiFi long-read sequencing and Hi-C chromatin conformation capture, we overcome limitations posed by low parasite biomass and the absence of in vitro culture for P. ovale wallikeri and P. malariae. These high quality reference genomes resolve previously inaccessible subtelomeric regions that include expanded gene families likely involved in host–parasite interactions, and they enhance our understanding of parasite persistence, transmission, immune evasion and comparative evolutionary studies. This work provides a critical foundation for including these neglected species in global malaria elimination efforts.

Plasmodium falciparum (Pf), Plasmodium ovalewallikeri (Pow), Plasmodium ovalecurtisi (Poc), and Plasmodium malariae (Pm) coexists in Kenya sympatrically. Some infections progress to classical symptoms of malaria prompting hospital visits, while others remain asymptomatic. There is limited information on whether the species composition status of infections in endemic areas influences progression to either asymptomatic or symptomatic infection. This cross-sectional study determined the composition...

Background: Angola is one of the most affected countries in sub-Saharan Africa and was off-track to meet the WHO Global Technical Strategy targeting of a 75% reduction in malaria incidence and mortality by 2025. Recent studies highlighted major knowledge gaps regarding malaria vectors in Angola, particularly secondary vectors. A malaria control project initiated in 2007 in Balombo (Benguela Province, central Angola) has monitored malaria dynamics for 18 years, revealing increased Plasmodium prevalence and more frequent detection of non-falciparum species, mainly Plasmodium malariae (in co-infection with P. falciparum) in villagers of the Balombo region. This study aimed to characterize Anopheles populations in this region by assessing species composition, behavioural patterns, and infection rate. And to a less extent, to compare the performance of two indoor and outdoor mosquito trapping methods. Methods: Surveys were conducted during the rainy (December 2023 and 2024) and dry seasons (July 2024) in villages around the town of Balombo. Adult mosquitoes were collected indoors and outdoors using CDC Light Traps and BG-Pro traps in randomly selected houses. Female Anopheles were morphologically and molecularly identified. Primary and secondary vectors were screened for Plasmodium spp. using qPCR-high resolution melting, and positive samples were sequenced. Results: A strong seasonal effect was observed in Anopheles populations, with higher abundance, diversity, and Plasmodium- infection rates during the rainy season. An. funestus remained the main vector, but Plasmodium spp. was also detected in five other species: An. arabiensis, An. gambiae, An. marshallii, An. rufipes, and An. maculipalpis. This is the first report of P. malariae in Anopheles mosquitoes and the first mention of the role of secondary vectors in malaria transmission in Benguela Province. Conclusion: This study provides a thorough and updated inventory of Anopheles species in the Balombo region. Molecular biology confirmed the presence of P. falciparum and P. malariae in several species of Anopheles underscoring the existence of a complex transmission system in villages of Balombo. Infected exophagic and exophilic Anopheles species, exhibiting opportunistic behaviour, likely contribute, as secondary vectors, to the increase of Plasmodiumspp. transmission in the study sites. Therefore, confirming the need to implement complementary interventions targeting outdoor malaria transmission.

Background: Angola is one of the most affected countries in sub-Saharan Africa and was off-track to meet the WHO Global Technical Strategy targeting of a 75% reduction in malaria incidence and mortality by 2025. Recent studies highlighted major knowledge gaps regarding malaria vectors in Angola, particularly secondary vectors. A malaria control project initiated in 2007 in Balombo (Benguela Province, central Angola) has monitored malaria dynamics for 18 years, revealing increased Plasmodium prevalence and more frequent detection of non-falciparum species, mainly Plasmodium malariae (in co-infection with P. falciparum) in villagers of the Balombo region. This study aimed to characterize Anopheles populations in this region by assessing species composition, behavioural patterns, and infection rate. And to a less extent, to compare the performance of two indoor and outdoor mosquito trapping methods. Methods: Surveys were conducted during the rainy (December 2023 and 2024) and dry seasons (July 2024) in villages around the town of Balombo. Adult mosquitoes were collected indoors and outdoors using CDC Light Traps and BG-Pro traps in randomly selected houses. Female Anopheles were morphologically and molecularly identified. Primary and secondary vectors were screened for Plasmodium spp. using qPCR-high resolution melting, and positive samples were sequenced. Results: A strong seasonal effect was observed in Anopheles populations, with higher abundance, diversity, and Plasmodium- infection rates during the rainy season. An. funestus remained the main vector, but Plasmodium spp. was also detected in five other species: An. arabiensis, An. gambiae, An. marshallii, An. rufipes, and An. maculipalpis. This is the first report of P. malariae in Anopheles mosquitoes and the first mention of the role of secondary vectors in malaria transmission in Benguela Province. Conclusion: This study provides a thorough and updated inventory of Anopheles species in the Balombo region. Molecular biology confirmed the presence of P. falciparum and P. malariae in several species of Anopheles underscoring the existence of a complex transmission system in villages of Balombo. Infected exophagic and exophilic Anopheles species, exhibiting opportunistic behaviour, likely contribute, as secondary vectors, to the increase of Plasmodiumspp. transmission in the study sites. Therefore, confirming the need to implement complementary interventions targeting outdoor malaria transmission.

Fundamental aspects of the biology of the third most prevalent human malaria species Plasmodium malariae, including the basis for its capacity to establish chronic, low-density infections associated with debilitating quartan fevers, remain poorly characterized, hampering control efforts. Here, we combined ex- vivo flowcytometric profiling of P. malariae isolates with infection studies in a recently developed humanised mouse model. We demonstrate a five-fold higher tropism of P. malariae compared...

YouTube video by Erik Cohen

Plasmodium malariae is a neglected human malaria parasite that causes persistent, often asymptomatic infections and remains difficult to diagnose. Despite being generally associated with lower prev...

Plasmodium malariae is a neglected human malaria parasite that causes persistent, often asymptomatic infections and remains difficult to diagnose. Despite being generally associated with lower prevalence and severity than other malaria parasites, P. malariae represents a significant public health concern, particularly in Africa, but also as a zoonosis in South America with monkey-adapted Plasmodium brasilianum. Plasmodium malariae and P. brasilianum population genetic structure, evolutionary history, and adaptive potential remain poorly understood, largely due to the historical scarcity of whole-genome data. By screening 226 monkey samples from two Latin American countries, we identified 20 Plasmodium-positives across multiple primate species, highlighting the persistence of this parasite in sylvatic transmission cycles. We also investigated the evolutionary history and genetic diversity of P. malariae using whole-genome sequencing data. By combining 79 newly sequenced genomes with 248 publicly available genomes, we analyzed a filtered dataset comprising 179 P. malariae, two P. brasilianum, and two P. malariae-like genomes. Population structure analyses revealed the presence of two genetically distinct but recombining clusters across African P. malariae populations. These clusters occur across multiple African countries at varying frequencies, without clear geographic segregation. Genome-wide scans of genetic differentiation and selection further identified numerous cluster-specific signatures of adaptation, including loci putatively involved in interactions with human hosts and mosquito vectors. Our results provide the first evidence for fine-scale population substructure within African P. malariae and reveal ongoing adaptive processes that may contribute to its persistence and transmission. By uncovering previously unrecognized genetic diversity and selection patterns, this study highlights the importance of population genomic approaches for understanding the evolutionary dynamics of this neglected malaria parasite.

Plasmodium malariae is a neglected human malaria parasite that causes persistent, often asymptomatic infections and remains difficult to diagnose. Despite being generally associated with lower prevalence and severity than other malaria parasites, P. malariae represents a significant public health concern, particularly in Africa, but also as a zoonosis in South America with monkey-adapted Plasmodium brasilianum. Plasmodium malariae and P. brasilianum population genetic structure, evolutionary history, and adaptive potential remain poorly understood, largely due to the historical scarcity of whole-genome data. By screening 226 monkey samples from two Latin American countries, we identified 20 Plasmodium-positives across multiple primate species, highlighting the persistence of this parasite in sylvatic transmission cycles. We also investigated the evolutionary history and genetic diversity of P. malariae using whole-genome sequencing data. By combining 79 newly sequenced genomes with 248 publicly available genomes, we analyzed a filtered dataset comprising 179 P. malariae, two P. brasilianum, and two P. malariae-like genomes. Population structure analyses revealed the presence of two genetically distinct but recombining clusters across African P. malariae populations. These clusters occur across multiple African countries at varying frequencies, without clear geographic segregation. Genome-wide scans of genetic differentiation and selection further identified numerous cluster-specific signatures of adaptation, including loci putatively involved in interactions with human hosts and mosquito vectors. Our results provide the first evidence for fine-scale population substructure within African P. malariae and reveal ongoing adaptive processes that may contribute to its persistence and transmission. By uncovering previously unrecognized genetic diversity and selection patterns, this study highlights the importance of population genomic approaches for understanding the evolutionary dynamics of this neglected malaria parasite.

CONCLUSIONS: The optimized protocol is well-suited for laboratories in Southern Vietnam.

Malaria, caused by mosquito-transmitted Plasmodium parasites, remains a major global health challenge. While P. falciparum accounts for most malaria deaths, the lesser-studied P. ovale spp. and P. malariae also contribute to disease burden across many endemic regions, typically causing milder but chronic infections. Here, we generated high-quality, chromosome-level reference genomes for P. ovale wallikeri, P. malariae, and P. falciparum directly from blood samples taken from natural infections. Using PacBio Ultra-Low-Input HiFi long-read sequencing and Hi-C chromatin conformation capture, we overcome limitations posed by low parasite biomass and the absence of in vitro culture for P. ovale wallikeri and P. malariae. These high quality reference genomes resolve previously inaccessible subtelomeric regions that include expanded gene families likely involved in host-parasite interactions, and they enhance our understanding of parasite persistence, transmission, immune evasion and comparative evolutionary studies. This work provides a critical foundation for including these neglected species in global malaria elimination efforts.

Malaria, caused by mosquito-transmitted Plasmodium parasites, remains a major global health challenge. While P. falciparum accounts for most malaria deaths, the lesser-studied P. ovale spp. and P. malariae also contribute to disease burden across many endemic regions, typically causing milder but chronic infections. Here, we generated high-quality, chromosome-level reference genomes for P. ovale wallikeri, P. malariae, and P. falciparum directly from blood samples taken from natural infections. Using PacBio Ultra-Low-Input HiFi long-read sequencing and Hi-C chromatin conformation capture, we overcome limitations posed by low parasite biomass and the absence of in vitro culture for P. ovale wallikeri and P. malariae. These high quality reference genomes resolve previously inaccessible subtelomeric regions that include expanded gene families likely involved in host-parasite interactions, and they enhance our understanding of parasite persistence, transmission, immune evasion and comparative evolutionary studies. This work provides a critical foundation for including these neglected species in global malaria elimination efforts.

MOTIVATION: Malaria, caused by Plasmodium parasites, imposes a significant public health burden. While Plasmodium falciparum remains the primary target of elimination strategies due to its high mortality rate, lesser-known species such as P. malariae, P. vivax, and P. knowlesi continue to contribute to substantial human morbidity. Genomic approaches, including whole-genome sequencing, offer powerful tools for understanding the biology, transmission, and emerging drug resistance of these...

Background: In sub-Saharan Africa, Plasmodium falciparum is unequivocally responsible for almost all malaria cases and deaths. However, the long-neglected human P. vivax, P. ovale, and P. malariae parasites also emerge as relevant, though their prevalence and contribution to the burden of the disease are very poorly appreciated. This study aimed to bridge this gap and surveyed the circulation of non-falciparum malaria parasites among febrile patients in four regions in south Senegal. Methods: Blood samples were obtained from 1990 febrile patients during the malaria transmission seasons of 2020, 2021, and 2022 in four southern regions in Senegal (Kedougou, Kolda, Tambacounda, and Ziguinchor). Genomic DNA was isolated and tested for Plasmodium infections by using a combination of Plasmodium genus-specific qPCR and Plasmodium species-specific nested PCR. Frequencies and distribution of Plasmodium species according to region, period, and patient demographics were analyzed using R. Spatial patterns of infection were further explored and visualized with QGIS software version 3.30.2. Results: The Plasmodium positivity rate was 73.43% of which 67.92% were unique Plasmodium species infections and 32.08% were co-infections by two or three Plasmodium species. The results described the ongoing circulation of all non-falciparum species in three of the four study regions, the non-detection of P. vivax and P. malariae parasites among the samples tested in Ziguinchor, the first evidence of non-falciparum infections in Kolda and Tambacounda, as well as the first report of P. ovale in Ziguinchor. Conclusions: Our data call on clinicians to account for these species in clinical prognoses, but also on the National Malaria Control Programme to consider these species in their policy of reducing the incidence of the disease with a view to eliminating malaria in Senegal.

Background: In sub-Saharan Africa, Plasmodium falciparum is unequivocally responsible for almost all malaria cases and deaths. However, the long-neglected human P. vivax, P. ovale, and P. malariae parasites also emerge as relevant, though their prevalence and contribution to the burden of the disease are very poorly appreciated. This study aimed to bridge this gap and surveyed the circulation of non-falciparum malaria parasites among febrile patients in four regions in south Senegal. Methods: Blood samples were obtained from 1990 febrile patients during the malaria transmission seasons of 2020, 2021, and 2022 in four southern regions in Senegal (Kedougou, Kolda, Tambacounda, and Ziguinchor). Genomic DNA was isolated and tested for Plasmodium infections by using a combination of Plasmodium genus-specific qPCR and Plasmodium species-specific nested PCR. Frequencies and distribution of Plasmodium species according to region, period, and patient demographics were analyzed using R. Spatial patterns of infection were further explored and visualized with QGIS software version 3.30.2. Results: The Plasmodium positivity rate was 73.43% of which 67.92% were unique Plasmodium species infections and 32.08% were co-infections by two or three Plasmodium species. The results described the ongoing circulation of all non-falciparum species in three of the four study regions, the non-detection of P. vivax and P. malariae parasites among the samples tested in Ziguinchor, the first evidence of non-falciparum infections in Kolda and Tambacounda, as well as the first report of P. ovale in Ziguinchor. Conclusions: Our data call on clinicians to account for these species in clinical prognoses, but also on the National Malaria Control Programme to consider these species in their policy of reducing the incidence of the disease with a view to eliminating malaria in Senegal.

In Brazil, Plasmodium infections in non-human primates (NHPs) have been associated with P. simium and P. brasilianum, which are morphologically and genetically similar to the human-infecting species P. vivax and P. malariae, respectively. Surveillance and monitoring of wild NHPs are crucial for understanding the distribution of these parasites and assessing the risk of zoonotic transmission. This study aimed to detect the presence of Plasmodium spp. genetic material in Platyrrhini primates from 47 municipalities in the states of Bahia and Minas Gerais. The animals were captured using Tomahawk-type live traps baited with fruit or immobilized with tranquilizer darts. Free-ranging individuals were chemically restrained via inhalation anesthesia using VetBag® or intramuscular anesthesia injection. Blood samples were collected from the femoral vein. A total of 298 blood and tissue samples were collected from 10 primate species across five genera: Alouatta caraya (25), Alouatta guariba clamitans (1), Callicebus melanochir (1), Callithrix geoffroyi (28), Callithrix jacchus (4), Callithrix kuhlii (31), Callithrix penicillata (175), Callithrix spp. hybrids (15), Leontopithecus chrysomelas (16), Sapajus robustus (1), and Sapajus xanthosthernos (1). Molecular diagnosis was performed using a nested PCR targeting the 18S small subunit ribosomal RNA (18S SSU rRNA) gene, followed by sequencing. Of the 298 samples analyzed, only one (0.3%) from Bahia tested positive for Plasmodium brasilianum/P. malariae. This represents the first detection of this parasite in a free-living C. geoffroyi in Brazil. These findings highlight the importance of continued surveillance of Plasmodium infections in NHPs to identify regions at risk for zoonotic transmission.

In Brazil, Plasmodium infections in non-human primates (NHPs) have been associated with P. simium and P. brasilianum, which are morphologically and genetically similar to the human-infecting species P. vivax and P. malariae, respectively. Surveillance and monitoring of wild NHPs are crucial for understanding the distribution of these parasites and assessing the risk of zoonotic transmission. This study aimed to detect the presence of Plasmodium spp. genetic material in Platyrrhini primates from 47 municipalities in the states of Bahia and Minas Gerais. The animals were captured using Tomahawk-type live traps baited with fruit or immobilized with tranquilizer darts. Free-ranging individuals were chemically restrained via inhalation anesthesia using VetBag® or intramuscular anesthesia injection. Blood samples were collected from the femoral vein. A total of 298 blood and tissue samples were collected from 10 primate species across five genera: Alouatta caraya (25), Alouatta guariba clamitans (1), Callicebus melanochir (1), Callithrix geoffroyi (28), Callithrix jacchus (4), Callithrix kuhlii (31), Callithrix penicillata (175), Callithrix spp. hybrids (15), Leontopithecus chrysomelas (16), Sapajus robustus (1), and Sapajus xanthosthernos (1). Molecular diagnosis was performed using a nested PCR targeting the 18S small subunit ribosomal RNA (18S SSU rRNA) gene, followed by sequencing. Of the 298 samples analyzed, only one (0.3%) from Bahia tested positive for Plasmodium brasilianum/P. malariae. This represents the first detection of this parasite in a free-living C. geoffroyi in Brazil. These findings highlight the importance of continued surveillance of Plasmodium infections in NHPs to identify regions at risk for zoonotic transmission.