scholarly journals Progress in Parasite Genomics and Its Application to Current Challenges in Malaria Control

2021 ◽  
Author(s):  
Cheikh Cambel Dieng ◽  
Colby T. Ford ◽  
Jennifer Huynh ◽  
Linda E. Amoah ◽  
Yaw A. Afrane ◽  
...  
Keyword(s):  
Malaria Control ◽  
Vaccine Development ◽  
Diagnostic Testing ◽  
Current Control ◽  
Control Mechanisms ◽  
African Countries ◽  
Malaria Vaccines ◽  
Antimalarial Resistance ◽  
Genetic Mechanisms ◽  
Parasite Genomics

A wide deployment of malaria control tools have significantly reduced malaria morbidity and mortality across Africa. However, in the last five to seven years, there has been a resurgence of malaria in several African countries, raising the questions of whether and why current control mechanisms are failing. Since the first Plasmodium falciparum reference genome was published in 2002, few thousands more representing a broad range of geographical isolates have been sequenced. These advances in parasite genomics have improved our understanding of mutational changes, molecular structure, and genetic mechanisms associated with diagnostic testing, antimalarial resistance, and preventive measures such as vaccine development. In this chapter, we summarize the current progress on: (1) genomic characteristics of P. falciparum; (2) novel biomarkers and revolutionary techniques for diagnosing malaria infections; and (3) current vaccine targets and challenges for developing efficacious and long-lasting malaria vaccines.

scholarly journals Incidence of Plasmodium falciparum malaria infection in 6-month to 45-year-olds on selected areas of Bioko Island, Equatorial Guinea

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Vicente Urbano Nsue Ndong Nchama ◽  
Ali Hamad Said ◽  
Ali Mtoro ◽  
Gertrudis Owono Bidjimi ◽  
Marta Alene Owono ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Control ◽  
Malaria Infection ◽  
Age Groups ◽  
Control Measures ◽  
Equatorial Guinea ◽  
Safety And Efficacy ◽  
Bioko Island ◽  
Malaria Vaccines

Abstract Background Extensive malaria control measures have been implemented on Bioko Island, Equatorial Guinea over the past 16 years, reducing parasite prevalence and malaria-related morbidity and mortality, but without achieving elimination. Malaria vaccines offer hope for reducing the burden to zero. Three phase 1/2 studies have been conducted successfully on Bioko Island to evaluate the safety and efficacy of whole Plasmodium falciparum (Pf) sporozoite (SPZ) malaria vaccines. A large, pivotal trial of the safety and efficacy of the radiation-attenuated Sanaria® PfSPZ Vaccine against P. falciparum is planned for 2022. This study assessed the incidence of malaria at the phase 3 study site and characterized the influence of socio-demographic factors on the burden of malaria to guide trial design. Methods A cohort of 240 randomly selected individuals aged 6 months to 45 years from selected areas of North Bioko Province, Bioko Island, was followed for 24 weeks after clearance of parasitaemia. Assessment of clinical presentation consistent with malaria and thick blood smears were performed every 2 weeks. Incidence of first and multiple malaria infections per person-time of follow-up was estimated, compared between age groups, and examined for associated socio-demographic risk factors. Results There were 58 malaria infection episodes observed during the follow up period, including 47 first and 11 repeat infections. The incidence of malaria was 0.25 [95% CI (0.19, 0.32)] and of first malaria was 0.23 [95% CI (0.17, 0.30)] per person per 24 weeks (0.22 in 6–59-month-olds, 0.26 in 5–17-year-olds, 0.20 in 18–45-year-olds). Incidence of first malaria with symptoms was 0.13 [95% CI (0.09, 0.19)] per person per 24 weeks (0.16 in 6–59-month-olds, 0.10 in 5–17-year-olds, 0.11 in 18–45-year-olds). Multivariate assessment showed that study area, gender, malaria positivity at screening, and household socioeconomic status independently predicted the observed incidence of malaria. Conclusion Despite intensive malaria control efforts on Bioko Island, local transmission remains and is spread evenly throughout age groups. These incidence rates indicate moderate malaria transmission which may be sufficient to support future larger trials of PfSPZ Vaccine. The long-term goal is to conduct mass vaccination programmes to halt transmission and eliminate P. falciparum malaria.

scholarly journals SARS-CoV-2 full length spike protein for COVID-19 vaccine development and diagnostic testing

2021 ◽  
Vol 147 (2) ◽  
pp. AB152
Author(s):  
Crystal Richardson ◽  
Mayuresh Abhyankar ◽  
Jillian Bracaglia ◽  
Sayeh Agah ◽  
Zachary Schuhmacher ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Diagnostic Testing ◽  
Full Length ◽  
Spike Protein

scholarly journals Competing interests, clashing ideas and institutionalizing influence: insights into the political economy of malaria control from seven African countries

2020 ◽  
Author(s):  
Justin Parkhurst ◽  
Ludovica Ghilardi ◽  
Jayne Webster ◽  
Robert W Snow ◽  
Caroline A Lynch
Keyword(s):  
Decision Making ◽  
Malaria Control ◽  
Qualitative Interviews ◽  
Sub Saharan Africa ◽  
African Countries ◽  
Health Community ◽  
Control Programmes ◽  
Control Decision ◽  
Sub Saharan ◽  
Economic Considerations

Abstract This article explores how malaria control in sub-Saharan Africa is shaped in important ways by political and economic considerations within the contexts of aid-recipient nations and the global health community. Malaria control is often assumed to be a technically driven exercise: the remit of public health experts and epidemiologists who utilize available data to select the most effective package of activities given available resources. Yet research conducted with national and international stakeholders shows how the realities of malaria control decision-making are often more nuanced. Hegemonic ideas and interests of global actors, as well as the national and global institutional arrangements through which malaria control is funded and implemented, can all influence how national actors respond to malaria. Results from qualitative interviews in seven malaria-endemic countries indicate that malaria decision-making is constrained or directed by multiple competing objectives, including a need to balance overarching global goals with local realities, as well as a need for National Malaria Control Programmes to manage and coordinate a range of non-state stakeholders who may divide up regions and tasks within countries. Finally, beyond the influence that political and economic concerns have over programmatic decisions and action, our analysis further finds that malaria control efforts have institutionalized systems, structures and processes that may have implications for local capacity development.

scholarly journals In silico characterisation of putative Plasmodium falciparum vaccine candidates in African malaria populations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
O. Ajibola ◽  
M. F. Diop ◽  
A. Ghansah ◽  
L. Amenga-Etego ◽  
L. Golassa ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Vaccine ◽  
Transmembrane Domain ◽  
Vaccine Development ◽  
Balancing Selection ◽  
Immune Recognition ◽  
African Countries ◽  
Vaccine Candidates ◽  
D Values ◽  
Tajima’S D

AbstractGenetic diversity of surface exposed and stage specific Plasmodium falciparum immunogenic proteins pose a major roadblock to developing an effective malaria vaccine with broad and long-lasting immunity. We conducted a prospective genetic analysis of candidate antigens (msp1, ama1, rh5, eba175, glurp, celtos, csp, lsa3, Pfsea, trap, conserved chrom3, hyp9, hyp10, phistb, surfin8.2, and surfin14.1) for malaria vaccine development on 2375 P. falciparum sequences from 16 African countries. We described signatures of balancing selection inferred from positive values of Tajima’s D for all antigens across all populations except for glurp. This could be as a result of immune selection on these antigens as positive Tajima’s D values mapped to regions with putative immune epitopes. A less diverse phistb antigen was characterised with a transmembrane domain, glycophosphatidyl anchors between the N and C- terminals, and surface epitopes that could be targets of immune recognition. This study demonstrates the value of population genetic and immunoinformatic analysis for identifying and characterising new putative vaccine candidates towards improving strain transcending immunity, and vaccine efficacy across all endemic populations.

scholarly journals Infectious Diseases Society of America Guidelines on the Diagnosis of Coronavirus Disease 2019 (COVID-19): Serologic Testing

2020 ◽  
Author(s):  
Kimberly E Hanson ◽  
Angela M Caliendo ◽  
Cesar A Arias ◽  
Janet A Englund ◽  
Mary K Hayden ◽  
...  
Keyword(s):  
Infectious Diseases ◽  
Best Practice ◽  
Vaccine Development ◽  
Clinical Performance ◽  
Diagnostic Testing ◽  
Molecular Diagnostic ◽  
Past Infection ◽  
Serologic Tests ◽  
Serologic Testing ◽  
Grade Methodology

Abstract Background The availability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serologic testing has rapidly increased. Current assays use a variety of technologies, measure different classes of immunoglobulin or immunoglobulin combinations, and detect antibodies directed against different portions of the virus. The overall accuracy of these tests, however, has not been well defined. The Infectious Diseases Society of America (IDSA) convened an expert panel to perform a systematic review of the coronavirus disease 2019 (COVID-19) serology literature and construct best-practice guidance related to SARS-CoV-2 serologic testing. This guideline is the fourth in a series of rapid, frequently updated COVID-19 guidelines developed by IDSA. Objective IDSA’s goal was to develop evidence-based recommendations that assist clinicians, clinical laboratories, patients, and policymakers in decisions related to the optimal use of SARS-CoV-2 serologic tests in a variety of settings. We also highlight important unmet research needs pertaining to the use of anti–SARS-CoV-2 antibody tests for diagnosis, public health surveillance, vaccine development, and the selection of convalescent plasma donors. Methods A multidisciplinary panel of infectious diseases clinicians, clinical microbiologists, and experts in systematic literature review identified and prioritized clinical questions related to the use of SARS-CoV-2 serologic tests. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was used to assess the certainty of evidence and make testing recommendations. Results The panel agreed on 8 diagnostic recommendations. Conclusions Information on the clinical performance and utility of SARS-CoV-2 serologic tests is rapidly emerging. Based on available evidence, detection of anti–SARS-CoV-2 antibodies may be useful for confirming the presence of current or past infection in selected situations. The panel identified 3 potential indications for serologic testing, including (1) evaluation of patients with a high clinical suspicion for COVID-19 when molecular diagnostic testing is negative and ≥2 weeks have passed since symptom onset, (2) assessment of multisystem inflammatory syndrome in children, and (3) conducting serosurveillance studies. The certainty of available evidence supporting the use of serology for either diagnosis or epidemiology was, however, graded as very low to moderate. For the most updated version of these guidelines, please go to https://www.idsociety.org/covid19guidelines.

scholarly journals Bovine Babesiosis in Turkey: Impact, Current Gaps, and Opportunities for Intervention

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1041
Author(s):  
Sezayi Ozubek ◽  
Reginaldo G. Bastos ◽  
Heba F. Alzan ◽  
Abdullah Inci ◽  
Munir Aktas ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Point Of Care ◽  
Animal Health ◽  
Current Control ◽  
Diagnostic Methods ◽  
Control Measures ◽  
Bovine Babesiosis ◽  
Research Programs ◽  
The Impact

Bovine babesiosis is a global tick-borne disease that causes important cattle losses and has potential zoonotic implications. The impact of bovine babesiosis in Turkey remains poorly characterized, but several Babesia spp., including B. bovis, B. bigemina, and B. divergens, among others and competent tick vectors, except Rhipicephalus microplus, have been recently identified in the country. Bovine babesiosis has been reported in all provinces but is more prevalent in central and highly humid areas in low and medium altitude regions of the country housing approximately 70% of the cattle population. Current control measures include acaricides and babesicidal drugs, but not live vaccines. Despite the perceived relevant impact of bovine babesiosis in Turkey, basic research programs focused on developing in vitro cultures of parasites, point-of-care diagnostic methods, vaccine development, “omics” analysis, and gene manipulation techniques of local Babesia strains are scarce. Additionally, no effective and coordinated control efforts managed by a central animal health authority have been established to date. Development of state-of-the-art research programs in bovine babesiosis to address current gaps in knowledge and implementation of long-term plans to control the disease will surely result in important economic, nutritional, and public health benefits for the country and the region.

scholarly journals Seeking Research Questions from Implementers: Considerations for Leveraging Ground Actors Research Needs in the Fight against Malaria in West Africa.

2020 ◽  
Author(s):  
Tete Sitou Amouh ◽  
Saidou Malam Ekoye ◽  
Césaire Damien Ahanhanzo ◽  
Tinga Robert Guiguemdé ◽  
Issiaka Sombié
Keyword(s):  
West Africa ◽  
World Bank ◽  
Malaria Control ◽  
Program Implementation ◽  
Neglected Tropical Diseases ◽  
Control Program ◽  
Monitoring And Evaluation ◽  
African Countries ◽  
Malaria Control Program ◽  
Research Questions

Abstract In Sahel countries in West Africa malaria remains a public health scourge. To strengthen the fight against malaria, weaknesses, and solutions must be identified before programs implementation. This study reports experiences gained from collaborations between decision-makers and researchers. This project was undertaken in the framework of the regional World Bank funded project titled: Malaria and Neglected Tropical Diseases in the Sahel (SM/NTD). The objectives of this World Bank program are to identifying bottlenecks in program implementation as well as the related research questions they enticed. National malaria control program managers and prioritization workshops were used as working method to identify research questions. These identified priority research questions were implemented in selected countries. The results of this study showed that priority issues were related to prevention, governance, drugs, monitoring, and evaluation of programs. The first five priority questions were related to (1) factors of compliance with drug doses for the second and third days during the seasonal chemoprevention (SMC) campaigns, (2) the contribution of community-based distributors to the management of severe cases of malaria in under 5 years-old children, (3) the SMC efficacy, (4) artemisinin-based combination therapy (ACTs) tolerance and efficacy according to existing guidelines, and (5) the quality of malaria control at all levels of the health system. In conclusion, this work showed the effectiveness of collaboration between implementers, programs managers, and researchers in identifying research questions. Furthermore, the results of this study will contribute to improve the implementation of malaria control programs across African countries.

scholarly journals Progress and Insights Toward an Effective Placental Malaria Vaccine

2021 ◽  
Vol 12 ◽  
Author(s):  
Benoît Gamain ◽  
Arnaud Chêne ◽  
Nicola K. Viebig ◽  
Nicaise Tuikue Ndam ◽  
Morten A. Nielsen
Keyword(s):  
Pregnant Women ◽  
Chondroitin Sulfate ◽  
Malaria Vaccine ◽  
Vaccine Development ◽  
Placental Malaria ◽  
Premature Delivery ◽  
Phase I Clinical Trials ◽  
Malaria Vaccines ◽  
Clinical Consequences ◽  
Chondroitin Sulfate A

In areas where Plasmodium falciparum transmission is endemic, clinical immunity against malaria is progressively acquired during childhood and adults are usually protected against the severe clinical consequences of the disease. Nevertheless, pregnant women, notably during their first pregnancies, are susceptible to placental malaria and the associated serious clinical outcomes. Placental malaria is characterized by the massive accumulation of P. falciparum infected erythrocytes and monocytes in the placental intervillous spaces leading to maternal anaemia, hypertension, stillbirth and low birth weight due to premature delivery, and foetal growth retardation. Remarkably, the prevalence of placental malaria sharply decreases with successive pregnancies. This protection is associated with the development of antibodies directed towards the surface of P. falciparum-infected erythrocytes from placental origin. Placental sequestration is mediated by the interaction between VAR2CSA, a member of the P. falciparum erythrocyte membrane protein 1 family expressed on the infected erythrocytes surface, and the placental receptor chondroitin sulfate A. VAR2CSA stands today as the leading candidate for a placental malaria vaccine. We recently reported the safety and immunogenicity of two VAR2CSA-derived placental malaria vaccines (PRIMVAC and PAMVAC), spanning the chondroitin sulfate A-binding region of VAR2CSA, in both malaria-naïve and P. falciparum-exposed non-pregnant women in two distinct Phase I clinical trials (ClinicalTrials.gov, NCT02658253 and NCT02647489). This review discusses recent advances in placental malaria vaccine development, with a focus on the recent clinical data, and discusses the next clinical steps to undertake in order to better comprehend vaccine-induced immunity and accelerate vaccine development.

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