Inflammatory cytokines play an important role in human immune responses to malarial disease. However, the role of these mediators in disease pathogenesis, and the relationship between host protection and injury remains unclear. A total of 248 cases of severePlasmodium falciparummalaria among children aged 3 months to 14 years residing in Bandiagara, Mali, were matched to cases of uncomplicated malaria and healthy controls. Using modified World Health Organization criteria for defining severe malaria, we identified 100 cases of cerebral malaria (coma, seizure, and obtundation), 17 cases of severe anemia (hemoglobin, 500,000/mm³). Significantly elevated levels (given as geometric mean concentrations in picograms/milliliter) of interleukin-6 (IL-6; 485.2 versus 54.1;P= <0.001), IL-10 (1,099.3 versus 14.1;P= <0.001), tumor necrosis factor alpha (10.1 versus 7.7;P= <0.001), and IL-12(p70) (48.9 versus 31.3;P= 0.004) in serum were found in severe cases versus healthy controls. Significantly elevated levels of IL-6 (485.2 versus 141.0;P= <0.001) and IL-10 (1,099.3 versus 133.9;P= <0.001) were seen in severe malaria cases versus uncomplicated malaria controls. Cerebral malaria was associated with significantly elevated levels of IL-6 (754.5 versus 311.4;P= 5 g/dl. Hyperparasitemia was associated with significantly lower levels of IL-6 (336.6 versus 602.1;P= 0.002). These results illustrate the complex relationships between inflammatory cytokines and disease inP. falciparummalaria.

Residents of malaria-endemic areas sometimes spontaneously clear Plasmodium falciparum infection without drug treatment, implying an important role for host factors such as immunity in this clearance. Host factors may also contribute to clearance of parasites resistant to a treatment drug. Chloroquine resistance is caused by point mutations in P. falciparum chloroquine resistance transporter (pfcrt) gene. We investigated the clearance of malaria parasites carrying the key chloroquine resistance-conferring PfCRT mutation K76T in patients treated with chloroquine. We found that the ability to clear these resistant parasites is strongly dependent on age (the best surrogate for protective immunity in endemic areas), suggesting that host immunity plays a critical role in the clearance of resistant P. falciparum infections. Age-adjusted comparison of subjects able to clear resistant parasites and those unable to do so provides a new phenotype for identifying host immune and genetic factors responsible for protective immunity against malaria.

Peripheral parasite density of Plasmodium falciparum is used as an indicator of malaria disease severity, but does not quantify central sequestration, which is important in the pathogenesis of severe disease. Malaria pigment, recognizable within the cytoplasm of phagocytic cells by light microscopy may represent a peripheral marker for parasite biomass. One hundred seventy-two index cases of severe malaria and 172 healthy age-, residence-, and ethnicity-matched controls with uncomplicated malaria in Bandiagara, Mali were analyzed prospectively for presence of malaria pigment. The presence of polymorphonuclear cell (PMN) and monocyte pigment was strongly associated with severe disease compared with uncomplicated malaria. Total PMN pigment burden in children with severe malaria was higher in those with cerebral manifestations and with combined cerebral manifestations and severe anemia (hemoglobin ≤ 5 g/dL) but was not associated with hyperparasitemia (> 500,000 asexual forms/mm³). Additionally, pigmented PMNs/mm³ was associated with a fatal outcome in patients with severe malaria. This study validates the presence of malaria pigment in monocytes and neutrophils as a marker for disease severity, and demonstrates that pigmented neutrophils are associated with cerebral malaria and with death in children with severe malaria.

BackgroundTrimethoprim-sulfamethoxazole (TS) prophylaxis is recommended for persons living with human immunodeficiency virus infection and acquired i

Background: To end the COVID-19 pandemic, a large part of the world must be immune to the virus by vaccination. Therefore, this study aimed to gauge intent to be vaccinated against COVID-19 among ordinary people and to identify attitudes towards vaccines and barriers for vaccine acceptance. Methods: The study population comprises 1880 people residing in different countries that answer a prepared questionnaire. The questionnaire topics are demographics, historical issues, participants’ attitudes and beliefs regarding vaccines, concerns, and vaccine hesitancy. Results: Attitudes and beliefs relating to vaccines in general, and the COVID-19 vaccine, were ascertained. Overall, 66.81% of the contributors would like to be vaccinated against COVID-19, while %33.19 did not intend to be vaccinated. Reasons for COVID-19 vaccine hesitancy included concern regarding vaccine side effects, fear of getting sick from the uptake of the vaccine, and the absence of accurate vaccine promotion news. Individuals with higher education believe that India (68.6%) produces the best vaccine (P<0.001), while healthcare workers think the Chinese vaccine (44.2%) is the best (P=0.020). Individuals with higher education have not been vaccinated, not be healthcare workers, and females were the most contributors to effective of the vaccine in reducing mortality from COVID-19 disease. Conclusion: Given the degree of hesitancy against COVID-19 vaccination, a multifaceted approach to facilitate vaccine uptake that includes vaccine education, behavioral change strategies, and health promotion, is paramount.

Treating malaria before immunizing has been standard in malaria vaccine field trials. To assess the impact of this practice on subsequent infection and disease incidence, we conducted a randomized cohort study in Bandiagara, Mali. Subjects received a treatment dose of sulfadoxine-pyrimethamine (SP) or no treatment at the beginning of the transmission season. Cumulative and age-specific incidence of clinical episodes was similar between the 2 groups, but SP treatment delayed the median time to first clinical episode from 38.5 to 68 days, and after this initial period of protection, disease incidence in the SP group quickly surpassed the incidence in the untreated group. Parasite densities during disease episodes were lower in the SP group. SP was chosen as the drug for initial parasite clearance for the following reasons: 1) it has been used in previous vaccine trials; 2) our studies have found it to have >99% efficacy in treating uncomplicated malaria in Mali compared to 85-90% efficacy for chloroquine in this area; 3) SP is the approved second-line antimalarial agent in Mali; and 4) its single-dose regimen ensures compliance when treatment is directly observed.