Data on malaria transmission intensity and prevalences of asexual parasites and of gametocytes were obtained in an urban district of Yaoundé, Cameroon. The transmission level from mosquito to human was determined by indoor night capture of mosquitoes on human volunteers, revealing a calculated entomological inoculation rate of 34 infectious bites per person per year. Only Anopheles gambiae and A. funestus contributed to malaria transmission and their distribution was seasonal. Cross-sectional surveys every 2 months from July 1999 to May 2000 (n = 965) showed average annual prevalences of 35% Plasmodium falciparum asexual parasites (range 29-38%) and 4.4% gametocytes (range 0-6.7%). Prevalence of high parasitaemia (> 400 parasites/microL) and of gametocytes was seasonal. Prevalence of asexual parasitaemias and of gametocytaemias was age-dependent. The potential infectious reservoir in this area is dominated by the age group 0-15 years, representing 75% of carriers of asexual parasites (P < 0.001), 85% of carriers of high parasitaemias (P < 0.001), and 83% of gametocyte carriers (P = 0.03). Full year logistic models developed from the available data accurately predicted parasite prevalences in subsequent analyses, thus permitting a precise determination of study samples for intervention and seroepidemiology studies, and analysis of the infectious reservoir in this area.
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http://dx.doi.org/10.1016/s0035-9203(03)90059-9 | DOI Listing |
PLoS Pathog
January 2025
LPHI, UMR 5294 CNRS/UM-UA15 Inserm, Université de Montpellier, Montpellier, France.
A sustained blood-stage infection of the human malaria parasite P. falciparum relies on the active exit of merozoites from their host erythrocytes. During this process, named egress, the infected red blood cell undergoes sequential morphological events: the rounding-up of the surrounding parasitophorous vacuole, the disruption of the vacuole membrane and finally the rupture of the red blood cell membrane.
View Article and Find Full Text PDFACS Infect Dis
January 2025
Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, United States.
Half the world's population is at risk of developing a malaria infection, which is caused by parasites of the genus . Currently, resistance has been identified to all clinically available antimalarials, highlighting an urgent need to develop novel compounds and better understand common mechanisms of resistance. We previously identified a novel tetrahydro-β-carboline compound, PRC1590, which potently kills the malaria parasite.
View Article and Find Full Text PDFis a common, waterborne gastrointestinal parasite that causes diarrheal disease worldwide. Currently there are no effective therapeutics to treat cryptosporidiosis in at-risk populations. Since natural products are a known source of anti-parasitic compounds, we screened a library of extracts and pure natural product compounds isolated from bacteria and fungi collected from subterranean environments for activity against .
View Article and Find Full Text PDFInt J Parasitol
January 2025
Institute of Parasitology, Department for Biological Sciences and Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1 A-1210 Vienna, Austria.
Cystoisospora suis, a porcine enteral parasite of the order Coccidia, is characterized by a complex life cycle, with asexual and sexual development in the epithelium of the host gut and an environmental phase as an oocyst. All developmental stages vary greatly in their morphology and function, and therefore excrete different bioactive molecules for intercellular communication. Due to their complex development, we hypothesized that the extracellular vesicles (EVs) cargo is highly dependent on the life cycle stages from which they are released.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.
Despite the enormous significance of malaria parasites for global health, some basic features of their ultrastructure remain obscure. Here, we apply high-resolution volumetric electron microscopy to examine and compare the ultrastructure of the transmissible male and female sexual blood stages of Plasmodium falciparum as well as the more intensively studied asexual blood stages revisiting previously described phenomena in 3D. In doing so, we challenge the widely accepted notion of a single mitochondrion by demonstrating the presence of multiple mitochondria in gametocytes.
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