One Health Approach to Arbovirus Control in Africa: Interests, Challenges, and Difficulties

Climate change and contagion: the emerging threat of zoonotic diseases in Africa

This article investigates the escalating occurrence of zoonotic diseases in Africa, attributing their spread to climate change and human activities. Africa's unique combination of biodiversity, reliance on animal husbandry, and swift urbanization heightens its susceptibility. Climate change disrupts ecosystems and animal habitats, intensifying human-wildlife interactions. Urbanization, inadequate sanitation, and insufficient healthcare infrastructure further facilitate disease spread. Climate-induced displacement adds another layer of complexity. Mitigation strategies include improving surveillance systems, fostering early detection via point-of-care diagnostics and digital contact tracing, and investing in vaccines and therapeutics. Our purpose of this is to advocate for sustainable land use, robust community-level public health systems, international cooperation, and resource-sharing. We also emphasize the need for effective vector-control policies, dedicated research funding, and annual awareness, vaccination, and early detection campaigns in endemic regions.

Mitigating the escalating threat of infectious diseases outbreaks in tropical Africa: a perspective examination of challenges and strategies for future preparedness

Background

The escalating threat of infectious disease outbreaks in Africa, particularly emerging and re-emerging diseases, necessitates urgent and comprehensive action. The frequency of these outbreaks demands a robust enhancement of notification and reporting systems to enable swift public health interventions.

Main body of the abstract

Tropical diseases such as malaria, COVID-19, typhoid fever, yellow fever, arboviruses, cholera, rabies, schistosomiasis, tuberculosis, black fungus, meningitis, evolving pathogens, and antimicrobial resistance pose significant health risks globally, especially in Sub-Saharan Africa. The region faces complexities in healthcare, including weak systems, inadequate surveillance, socioeconomic disparities, and other issues. Poor health literacy, traditional practices, and distrust hinder effective disease control and contribute to disease emergence in Sub-Saharan Africa. Continuous research and global collaboration are essential to address these public health concerns, especially given Africa's unique challenges. Disease surveillance emerges as a highly effective strategy, crucial in regions vulnerable to infectious diseases. Establishing and strengthening comprehensive surveillance and reporting systems at individual, regional, national, and international levels is crucial due to the unpredictable nature of borderless outbreaks and their significant impact on morbidity, mortality, and economic stability. National surveillance relies heavily on effective control mechanisms within local community areas, necessitating the active involvement of medical personnel. Successful systems depend on functional countries using collected data for timely warnings and localized interventions. Stakeholders, including governments, health authorities, and international organizations, must collaborate urgently to implement and sustain these vital systems, mitigating the devastating consequences of infectious disease outbreaks. Additionally, a holistic approach is crucial, involving prioritized local production of vaccines, medicines, and diagnostics through initiatives like the African Vaccine Producers Initiative. This approach emphasizes the need for domestic pharmaceutical production, intensified public awareness campaigns, and the training of the next generation of global health leaders, ensuring multidimensional strategies, political and diplomatic skills, and evidence-based assessments.

Conclusion

Collaboration among governments, international organizations, and educational institutions is essential for successful policy advocacy and implementation to strengthen health security and mitigate the continuous rise of infectious diseases on the continent.

Cloning and phylogenetic analysis of N protein gene from Rift Valley Fever Virus (RVFV)

Rift Valley Fever (RVF) is a mosquito-borne viral zoonosis caused by RVFV in humans and livestock. Currently, there are no approved vaccines or antiviral therapies available. Additionally, in Saudi Arabia, there is a lack of a routine screening system to monitor RVFV in humans and animals which hinders to design and develop the preventive measures as well as the prediction of future outbreaks and the potential re-emergence of RVFV. Hence, we have performed the cloning, sequencing, and phylogenetic analysis, of nucleocapsid (N) protein gene. The sequence analysis showed high similarities with RVFV isolates reported from humans and animals. The highest similarity (99.5%) was observed with an isolate from Saudi Arabia (KU978775-Human) followed by 99.1% with four RVFV isolates (Human and Bovine) from other locations. A total of 51 nucleotides and 31 amino acid variations were observed throughout the N protein gene sequences. The phylogenetic relationship formed closed clusters with other isolates collected from Saudi Arabia. Thus, we report of the cloning, sequencing, and phylogenetic analysis of the RVFV-N protein gene from Saudi Arabia.

Development of Vaccines against Emerging Mosquito-Vectored Arbovirus Infections

Among emergent climate-sensitive infectious diseases, some mosquito-vectored arbovirus infections have epidemiological, social, and economic effects. Dengue virus (DENV), West Nile virus (WNV), and Chikungunya virus (CHIKV) disease, previously common only in the tropics, currently pose a major risk to global health and are expected to expand dramatically in the near future if adequate containment measures are not implemented. The lack of safe and effective vaccines is critical as it seems likely that emerging mosquito-vectored arbovirus infections will be con-trolled only when effective and safe vaccines against each of these infections become available. This paper discusses the clinical characteristics of DENV, WNV, and CHIKV infections and the state of development of vaccines against these viruses. An ideal vaccine should be able to evoke with a single administration a prompt activation of B and T cells, adequate concentrations of protecting/neutralizing antibodies, and the creation of a strong immune memory capable of triggering an effective secondary antibody response after new infection with a wild-type and/or mutated infectious agent. Moreover, the vaccine should be well tolerated, safe, easily administrated, cost-effective, and widely available throughout the world. However, the development of vaccines against emerging mosquito-vectored arbovirus diseases is far from being satisfactory, and it seems likely that it will take many years before effective and safe vaccines for all these infections are made available worldwide.

Mosquito-Borne Arboviruses Occurrence and Distribution in the Last Three Decades in Central Africa: A Systematic Literature Review

Arboviruses represent a real public health problem globally and in the Central African subregion in particular, which represents a high-risk zone for the emergence and re-emergence of arbovirus outbreaks. Furthermore, an updated review on the current arbovirus burden and associated mosquito vectors is lacking for this region. To contribute to filling this knowledge gap, the current study was designed with the following objectives: (i) to systematically review data on the occurrence and distribution of arboviruses and mosquito fauna; and (ii) to identify potential spillover mosquito species in the Central African region in the last 30 years. A web search enabled the documentation of 2454 articles from different online databases. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) and the quality of reporting of meta-analyses (QUORUM) steps for a systematic review enabled the selection of 164 articles that fulfilled our selection criteria. Of the six arboviruses (dengue virus (DENV), chikungunya virus (CHIKV), yellow fever virus (YFV), Zika virus (ZIKV), Rift Valley fever virus (RVFV), and West Nile virus (WNV)) of public health concern studied, the most frequently reported were chikungunya and dengue. The entomological records showed >248 species of mosquitoes regrouped under 15 genera, with Anopheles (n = 100 species), Culex (n = 56 species), and Aedes (n = 52 species) having high species diversity. Three genera were rarely represented, with only one species included, namely, Orthopodomyia, Lutzia, and Verrallina, but individuals of the genera Toxorhinchites and Finlayas were not identified at the species level. We found that two Aedes species (Ae. aegypti and Ae. albopictus) colonised the same microhabitat and were involved in major epidemics of the six medically important arboviruses, and other less-frequently identified mosquito genera consisted of competent species and were associated with outbreaks of medical and zoonotic arboviruses. The present study reveals a high species richness of competent mosquito vectors that could lead to the spillover of medically important arboviruses in the region. Although epidemiological studies were found, they were not regularly documented, and this also applies to vector competence and transmission studies. Future studies will consider unpublished information in dissertations and technical reports from different countries to allow their information to be more consistent. A regional project, entitled "Ecology of Arboviruses" (EcoVir), is underway in three countries (Gabon, Benin, and Cote d'Ivoire) to generate a more comprehensive epidemiological and entomological data on this topic.