Sympatric Plasmodium falciparum isolates from Venezuela have structured var gene repertoires

BACKGROUND: The human malaria parasite Plasmodium falciparum expresses adhesins belonging to the erythrocyte membrane protein 1 (PfEMP1) family on the surface of the infected host erythrocyte. These antigens elicit a strain-specific antibody response that is associated with protection from disease. During clonal expansion of blood-stage parasites, the surface phenotype of the infected erythrocyte changes because of transcriptional switching among the 40 to 50 members of the highly polymorphic var multi-gene family which encode PfEMP1 variants. Studies to date have compared var repertoires of natural isolates from various geographical locations but have not addressed any within-population structure that may exist among repertoires. METHODS: Distinct parasite genotypes from a single population co-circulating among a defined group of hosts were selected. PCR products encoding the DBL-α domain of PfEMP-1 were cloned and sequenced from each of three isolates. Repertoire similarity was statistically evaluated using combinatorial analysis. The chromosomal location of shared sequences was inferred from similarity to dbl-α of known location in the 3D7 genome. RESULTS: Sympatric parasites were found to share few var gene sequences, even when alleles at other polymorphic loci were shared. A number of the sequences shared by at least two of the isolates studied were found to be related to 3D7 genomic sequences with non-telomeric chromosomal locations, or atypical domain structures, which may represent globally conserved loci. CONCLUSION: The parasite population studied is structured, with minimal overlap in PfEMP1 repertoires. The var gene family accumulates diversity more rapidly than other antigen genes examined. This may be facilitated by ectopic recombination among the sub-telomeric regions of P. falciparum chromosomes

Knowledge, attitudes, and practices towards COVID-19 among Venezuelans during the 2020 epidemic:An online cross-sectional survey

BACKGROUND: COVID-19 threatens health systems worldwide, but Venezuela's system is particularly vulnerable. To prevent the spread of COVID-19, individuals must adopt preventive behaviors. However, to encourage behavior change, we must first understand current knowledge, attitudes, and practices (KAPs) that inform response to this health threat. METHODS: We explored KAPs among Venezuelans using a cross-sectional, internet-based questionnaire. The questionnaire explored individuals' knowledge about COVID-19; their attitudes toward the world's and the Venezuelan authorities' abilities to control it; and their self-reported practices. We also collected demographic data. Binomial logistic regression analyses were used to predict the adoption of preventive behaviors based on demographic variables, individual knowledge level, and individual attitudes. RESULTS: 3122 individuals completed the questionnaire. Participants had a high level of knowledge about COVID-19. They expressed high levels of optimism that the world would eventually control COVID-19, but they were very pessimistic about the public authorities in Venezuela. Most participants adopted preventive practices. Binomial regression suggests younger people, less educated people, and manual laborers hold lower levels of knowledge, and these groups, as well as men, were less likely to adopt preventive practices. Knowledge, by itself, had no association with optimism and little association with self-reported practices. CONCLUSIONS: As other KAP studies in Latin America found, knowledge is not sufficient to prompt behavior change. Venezuelans' pessimism about their own country's ability should be explored in greater depth. Health promotion in Venezuela may wish to target the most at risk groups: men, younger people, less educated people, and manual laborers

“What will the doctor give me, the same painkiller?”:a qualitative study exploring health-care seeking and symptoms self-management among patients for the treatment of long-term chikungunya disease, in Curaçao

Background: Long-term chikungunya disease, characterized by persistent disabling rheumatic symptoms, including poly-arthralgia/arthritis of severe pain intensity, can persist for years after infection with the re-emerging mosquito-borne chikungunya virus. Although persistent symptoms and pain severity are important determinants of health-care seeking and self-management of symptoms, research on these in relation to long-term chikungunya disease is scarce. This study aimed to explore the perceived benefits and perceived barriers concerning health-care seeking, based on the Health Belief Model, and the symptoms self-management strategies used for health outcome improvement among individuals affected by long-term chikungunya disease.Methods: An exploratory qualitative descriptive study was conducted with 20 purposively selected adults (17 females and 3 males) with persistent rheumatic symptoms, recruited from an ongoing longitudinal chikungunya cohort, in Curaçao. Semi-structured interviews were carried out, audio-recorded, and transcribed. An iterative coding process was used for themes identification through inductive thematic analyses.Results: No perceived benefits in health-care seeking were reported. Identified themes in relation to perceived barriers were: (1) health-care seeking at disease onset; (2) general practitioners (GPs) perceptions and awareness of persistent symptoms; (3) challenges for medical referrals and support; (4) no validation of symptoms and challenges accessing therapy; (5) health system restrictions; and (6) social stigmatization of psychological help. These perceived barriers have led participants to self-manage persistent symptoms. Over-the-counter pharmacological and/or non-pharmacological treatments were used without consulting GPs. Identified themes were: (1) self-medication of symptoms; and (2) self-management true non-pharmacological treatments.Conclusions: To promote the benefits of long-term health-care seeking and subsequently reduce the possible harmful use of analgesics, a collaborative physician-patient therapeutic relationship need to be encouraged. To facilitate this, important shifts may be needed in chikungunya sequalae education of both patients and health-care professionals, and policy makers need to revise health systems for the long-term provision of multidisciplinary care to achieve beneficial health outcomes in long-term chikungunya disease.</p

Evaluation of Olyset™ insecticide-treated nets distributed seven years previously in Tanzania

BACKGROUND: Insecticide-treated nets represent currently a key malaria control strategy, but low insecticide re-treatment rates remain problematic. Olyset™ nets are currently one of two long-lasting insecticidal nets recommended by WHO. An assessment was carried out of the effect of Olyset™ nets after seven years of use in rural Tanzania. METHODS: A survey of Olyset™ nets was conducted in two Tanzanian villages to examine their insecticide dosage, bioassay efficacy and desirability compared with ordinary polyester nets. RESULTS: Of 103 randomly selected nets distributed in 1994 to 1995, 100 could be traced. Most nets were in a condition likely to offer protection against mosquito biting. Villagers appreciated mainly the durability of Olyset™ nets and insecticide persistence. People disliked the small size of these nets and the light blue colour and preferred a smaller mesh size, features that can easily be modified. At equal price, 51% said they would prefer to buy an Olyset™ net and 49% opted for an ordinary polyester net. The average permethrin content was 33%-41% of the initial insecticide dose of 20,000 mg/Kg. Bioassay results indicated high knock-down rates at 60 minutes, but the mosquito mortality after 24 hours was rather low (mean: 34%). No significant correlation was found between bioassay results and insecticide concentration in and on the net. CONCLUSIONS: Olyset™ nets are popular, durable and with a much longer insecticide persistence than ordinary polyester nets. Hence, Olyset™ nets are one of the best choices for ITN programmes in rural malaria-endemic areas

COVID-19 Vaccine Hesitancy in Three Latin American Countries:Reasons Given for Not Becoming Vaccinated in Colombia, Ecuador, and Venezuela

Although vaccines have been developed to prevent COVID-19, vaccine hesitancy is a significant barrier for vaccination programs. Most research on COVID-19 vaccine hesitancy has blamed misinformation and misstated concerns about effectiveness, safety, and side effects of these vaccines. The preponderance of these studies has been performed in the Global North. Although Latin American has been substantially and negatively impacted by COVID-19, few studies have examined COVID-19 vaccine hesitancy there. We explored reasons volunteered for COVID-19 vaccine hesitancy from a sample of 1,173 Colombians, Ecuadorians, and Venezuelans. Overall, COVID-19 vaccine hesitancy in these three countries is higher than desirable, but most people who are COVID-19 vaccine hesitant offered one reason or fewer. The reasons offered are diverse, including myths and exaggerations, but also individual-level contraindications for vaccination and structural barriers. Because of the diversity of reasons, single-issue mass campaigns are unlikely to bring about large shifts in COVID-19 vaccine hesitancy in Colombia, Ecuador, and Venezuela. Our data suggest that interpersonal communication, particularly in Ecuador, and addressing structural concerns, particularly in Venezuela, are likely to have the greatest impact on vaccine uptake

Use and misuse of a discount voucher scheme as a subsidy for insecticide-treated nets for malaria control in southern Tanzania

Since 1997, discount vouchers for insecticide-treated nets (ITNs) have been used in two rural districts of southern Tanzania as a way to target subsidies to children under 5 years and pregnant women. We assessed appropriate use and misuse of discount vouchers through a follow-up study of 104 randomly selected vouchers. We traced these vouchers from their original issue in mother-and-child health (MCH) clinics through to being redeemed at a sales agent. We found that all vouchers that reached the target population (100%, 56/56) were used to buy an ITN. Moreover, 94% of the ITNs bought with vouchers were used by those intended, women and children under 5 years. However, up to 48% (50/104) of the vouchers had been misused at the clinics that issued them. Nevertheless, large-scale misuse occurred only at three of 21 clinics. Although most women slept under a net while pregnant, the use of voucher-subsidized ITNs during pregnancy was low despite widespread knowledge of the scheme. Parents had apparently decided to buy the subsidized ITNs once the child was born and not during pregnancy. Importantly, in 20% of households the only existing net had been bought with a voucher. Our findings suggest that vouchers are properly used by the target population, and that to minimize voucher leakage, control measures are needed at MCH clinics and to a certain extent for commercial sales agents. Increased awareness among the whole community on the right to receive a discount voucher may also help to control misuse at health facilitie

Evaluating and strengthening the health system of Curacao to improve its performance for future outbreaks of vector-borne diseases

BACKGROUND: Vector-borne diseases (VBDs) such as dengue, chikungunya, and Zika pose a significant challenge to health systems in countries they affect, especially countries with less developed healthcare systems. Therefore, countries are encouraged to work towards more resilient health systems. This qualitative study aims to examine the performance of the health system of the Dutch Caribbean island of Curaҫao regarding the prevention and control of VBDs in the last decade by using the WHO health system building blocks. METHODS: From November 2018 to December 2020, a multi-method qualitative study was performed in Curaçao, applying content analysis of documents (n = 50), five focus group discussions (n = 30), interviews with experts (n = 11) and 15 observation sessions. The study was designed based on the WHO framework: health system building blocks. Two cycles of inductive and deductive coding were employed, and Nvivo software was used to analyse the data. RESULTS: This study’s data highlighted the challenges (e.g. insufficient oversight, coordination, leadership skills, structure and communication) that the departments of the health system of Curaҫao faced during the last three epidemics of VBDs (2010–2020). Furthermore, low levels of collaboration between governmental and non-governmental organisations (e.g. semi-governmental and private laboratories) and insufficient capacity building to improve skills (e.g. entomological, surveillance skills) were also observed. Lastly, we observed how bottlenecks in one building block negatively influenced other building blocks (e.g. inadequate leadership/governance obstructed the workforce's performance). CONCLUSIONS: This study uncovers potential organisational bottlenecks that have affected the performance of the health system of Curaҫao negatively. We recommend starting with the reinforcement of oversight of the integrated vector management programme to ensure the development, implementation and evaluation of related legislation, policies and interventions. Also, we recommend evaluating and reforming the existing administrative and organisational structure of the health system by considering the cultural style, challenges and barriers of the current health system. More efforts are needed to improve the documentation of agreements, recruitment and evaluation of the workforce's performance. Based on our findings, we conceptualised actions to strengthen the health system's building blocks to improve its performance for future outbreaks of infectious diseases. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13071-021-05011-x

Complete Coding Sequences of Five Dengue Virus Type 2 Clinical Isolates from Venezuela Obtained through Shotgun Metagenomics

Dengue is a disease endemic in Latin American countries, like Venezuela, and has become one of the most important public health problems. We report five complete coding sequences of dengue virus serotype 2 (DENV-2) isolated from DENV-infected patients in Venezuela. Phylogenetic analysis placed the isolates within the American/Asian genotype

Health-related impact on quality of life and coping strategies for chikungunya:A qualitative study in Curaçao

Chikungunya is an emerging public health problem in tropical and subtropical regions, due to ongoing transmission and its incapacitating acute disease phase, and chronic sequelae. The disease is responsible for a major impact on Health Related Quality of Life (HRQoL), which may last several years. To our knowledge, this study is the first qualitative examination of HRQoL and coping strategies of chikungunya-infected individuals.Qualitative research methods consisted of 20 in-depth interviews and seven Focus Group Discussions (FGDs), n = 50. Analysis was based on the principles of the grounded theory.Different impacts on HRQoL were reported. The physical and emotional domains of the HRQoL were mainly affected by chikungunya, while social and individual financial consequences were limited. Individual financial impact was limited through the universal health care program of Curaçao. Long-term lingering musculoskeletal and other manifestations caused significant pain and limited mobility. Hence, participants experienced dependency, impairment of normal daily life activities, moodiness, hopelessness, a change of identity, and insecurity about their future. The unpredictable nature and consequences of chikungunya gave rise to various coping strategies. Problem-focused coping styles led to higher uptake of medical care and were linked to more negative impact of HRQoL, whereas emotional coping strategies focusing on acceptance of the situation were linked to less uptake of medical care and more positive impact on HRQoL.This study provides an in-depth understanding of acute and long-term HRQoL impact of chikungunya. The results can better inform health promotion policies and interventions. Messages to the public should focus on promoting healthy and efficient coping strategies, in order to prevent additional stress in affected individuals

Methods for the Elucidation of Protein-Small Molecule Interactions

Understanding the interactions between small molecules and proteins can be approached from different perspectives and is important for the advancement of basic science and drug development. Chemists often use bioactive small molecules, such as natural products or synthetic compounds, as probes to identify therapeutically relevant protein targets. Biochemists and biologists often begin with a specific protein and seek to identify the endogenous metabolites that bind to it. These interests have led to the development of methodology that relies heavily on synthetic and analytical chemistry to identify protein-small molecule and protein-metabolite interactions. Here, we survey these strategies, highlighting key findings, to demonstrate the value of these approaches in answering important chemical and biological questions