Knowledge,attitudes, and practices regarding schistosomiasis infection and prevention: A mixed-methods study among endemic communities of western Uganda

IntroductionIn Uganda, schistosomiasis (re)infections have continued to remain high despite the implementation of mass drug administration and sensitization campaigns aimed at controlling the disease. This could imply that there are some barriers to the implemented preventive measures. We conducted a mixed-methods study in Kagadi and Ntoroko districts around Lake Albert to assess knowledge, attitudes, and practices regarding schistosomiasis and to explore and understand perspectives regarding the disease.Materials and methodsSemi-structured survey questionnaires were administered to 337 household adults selected through systematic random sampling. We also interviewed 12 participants and held 28 focus-group discussion sessions with 251 individuals respectively. Quantitative data was analysed using frequencies, percentages, and chi-square tests for associations, while themes and sub-themes were used to analyse qualitative data respectively.FindingsA total of 98.5%, 81.3%, and 78.5% had heard about schistosomiasis, and knew the main transmission modes and symptoms, respectively. The majority (75.8%) said avoiding contact with water was a preventative way, while 67.5% said observing signs and symptoms was a form of diagnosis. Furthermore, 98.4% and 73.4% said it was important to defecate in latrines and to avoid contact with contaminated water respectively. However, it is difficult to avoid contact with lake water because it is the only source of livelihood, especially for fisher communities. Open defecation is commonly practiced along the lake due to insufficient space and difficulties in the construction of latrines. Myths and misconceptions reported include; lake water is safe, gassing in water causes transmission, fetching water early in the morning and from deep water is safe, and feces in the lake water act as a bait for catching fish.Conclusions and recommendationsDespite adequate knowledge of schistosomiasis and a positive attitude towards its prevention, existing myths and misconceptions, coupled with persistent risky water, sanitation, and hygiene practices still pose a challenge. A more robust community-based awareness intervention using bottom-up participatory approaches, accompanied by the provision of clean and safe water sources and increasing latrine coverage, could provide lasting solutions to these barriers.     

The development of broad-spectrum antiviral medical countermeasures to treat viral hemorrhagic fevers caused by natural or weaponized virus infections

The Joint Program Executive Office for Chemical, Biological, Radiological, and Nuclear Defense (JPEO-CBRND) began development of a broad-spectrum antiviral countermeasure against deliberate use of high-consequence viral hemorrhagic fevers (VHFs) in 2016. The effort featured comprehensive preclinical research, including laboratory testing and rapid advancement of lead molecules into nonhuman primate (NHP) models of Ebola virus disease (EVD). Remdesivir (GS-5734, Veklury, Gilead Sciences) was the first small molecule therapeutic to successfully emerge from this effort. Remdesivir is an inhibitor of RNA-dependent RNA polymerase, a viral enzyme that is essential for viral replication. Its robust potency and broad-spectrum antiviral activity against certain RNA viruses including Ebola virus and Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) led to its clinical evaluation in randomized, controlled trials (RCTs) in human patients during the 2018 EVD outbreak in the Democratic Republic of the Congo (DRC) and the ongoing Coronavirus Disease 2019 (COVID-19) pandemic today. Remdesivir was recently approved by the US Food and Drug Administration (FDA) for the treatment of COVID-19 requiring hospitalization. Substantial gaps remain in improving the outcomes of acute viral infections for patients afflicted with both EVD and COVID-19, including how to increase therapeutic breadth and strategies for the prevention and treatment of severe disease. Combination therapy that joins therapeutics with complimentary mechanisms of action appear promising, both preclinically and in RCTs. Importantly, significant programmatic challenges endure pertaining to a clear drug and biological product development pathway for therapeutics targeting biodefense and emerging pathogens when human efficacy studies are not ethical or feasible. For example, remdesivir’s clinical development was facilitated by outbreaks of Ebola and SARS-CoV-2; as such, the development pathway employed for remdesivir is likely to be the exception rather than the rule.The current regulatory licensure pathway for therapeutics targeting rare, weaponizable VHF agents is likely to require use of FDA’s established Animal Rule (21 CFR 314.600–650 for drugs; 21 CFR 601.90–95 for biologics). The FDA may grant marketing approval based on adequate and well-controlled animal efficacy studies when the results of those studies establish that the drug is safe and likely to produce clinical benefit in humans. In practical terms, this is anticipated to include a series of rigorous, well-documented, animal challenge studies, to include aerosol challenge, combined with human safety data. While small clinical studies against naturally occurring, high-consequence pathogens are typically performed where possible, approval for the therapeutics currently under development against biodefense pathogens will likely require the Animal Rule pathway utilizing studies in NHPs. We review the development of remdesivir as illustrative of the effort that will be needed to field future therapeutics against highly lethal, infectious agents.     

18O-exchange evidence that mutations of arginine in a signature sequence for P-type pumps affect inorganic phosphate binding

We have proposed a model for part of the catalytic site of P-type pumps in which arginine in a signature sequence functions like lysine in P-loop-containing enzymes that catalyze adenosine 5'-triphosphate hydrolysis [Smirnova, I. N., Kasho, V. N., and Faller, L. D. (1998) FEBS Lett. 431, 309-314]. The model originated with evidence from site-directed mutagenesis that aspartic acid in the DPPR sequence of Na,K-ATPase binds Mg(2+) [Farley, R. A., et al. (1997) Biochemistry 36, 941-951]. It was developed by assuming that the catalytic domain of P-type pumps evolved from enzymes that catalyze phosphoryl group transfer. The functions of the positively charged amino group in P-loops are to bind substrate and to facilitate nucleophilic attack upon phosphorus by polarizing the gamma-phosphorus-oxygen bond. To test the prediction that the positively charged guanidinium group of R596 in human alpha(1) Na,K-ATPase participates in phosphoryl group transfer, the charge was progressively decreased by site-directed mutagenesis. Mutants R596K, -Q, -T, -M, -A, -G, and -E were expressed in yeast membranes, and their ability to catalyze phosphorylation with inorganic phosphate was evaluated by following (18)O exchange. R596K, in which the positive charge is retained, resembled the wild type. Substitution of a negative charge (R596E) resulted in complete loss of activity. The remaining mutants with uncharged side chains had both lowered affinity for inorganic phosphate and altered phosphate isotopomer distributions, consistent with increased phosphate-off rate constants compared to that of the wild type. Therefore, mutations of R596 strengthen our hypothesis that the oppositely charged side chains of the DPPR peptide in Na,K-ATPase form a quaternary complex with magnesium phosphate.