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Rwanda is located in the Central East African region where several viral pathogens with global importance were originally described, including human immunodeficiency virus (HIV), Ebola, Zika, Rift Valley Fever (RVF), dengue and a long list of other neglected tropical viral pathogens. Due to many factors, this region has the potential to become a global hotspot for viral emergence. In Rwanda, viral diseases are underreported and the question is whether this is due to the absence of these viruses or a lack of investigation. Like many developing countries, capabilities in Rwanda need improvement despite research efforts throughout the years. This review describes the status of human and animal virus research in Rwanda and identifies relevant research and operational gaps. A comprehensive search was conducted in PubMed for virus research in Rwanda: 233 primary studies on viruses/viral diseases are indexed with connection to Rwanda. From 1958 to 2020, yearly publications generally increased and HIV/acquired immunodeficiency syndrome is the most studied virus. Compared with human viruses, few studies focus on animal and/or zoonotic viruses. The occurrence of the current severe acute respiratory syndrome coronavirus 2 pandemic shows strengthening warning and surveillance systems is critical to efficient preparedness and response. We recommend investment in human capacity, laboratory facilities and research to inform policy for viral surveillance in Rwanda. [ABSTRACT FROM AUTHOR]

Chikungunya virus (CHIKV) has experienced 2 major expansion events in the last decade. The most recently emerged sublineage (ECSA-V) was shown to have increased efficiency in a historically secondary vector, Aedes albopictus, leading to speculation that this was a major factor in expansion. Subsequently, a number of experimental studies focused on the vector competence of CHIKV, as well as transmission modeling efforts. Mathematical models have used these data to inform their own investigations, but some have incorrectly parameterized the extrinsic incubation period (EIP) of the mosquitoes, using vector competence data. Vector competence and EIP are part of the same process but are not often correctly reported together. Thus, the way these metrics are used for model parameterization can be problematic. We offer suggestions for bridging this gap for the purpose of standardization of reporting and to promote appropriate use of experimental data in modeling efforts. [ABSTRACT FROM AUTHOR]

Zika virus has emerged in the Americas, where dengue virus is endemic. Among the 4 serotypes of dengue virus, antibody-dependent enhancement is thought to enhance viral replication and disease severity. Reports suggest that anti-dengue virus antibody may enhance Zika virus replication. We investigated whether Zika virus antibodies enhance dengue virus replication, by exposing C57Bl/6 mice to Zika virus. Polyclonal serum was verified for strong Zika virus-neutralizing, dengue virus-subneutralizing capacity. Then we determined the enhancement capabilities of Zika virus-immune serum for dengue virus in vitro. We showed that Zika virus antibodies have the ability to enhance dengue virus infections, which is important, because in many Zika virus-affected areas, dengue virus is expected to remain endemic. [ABSTRACT FROM AUTHOR]

Recent efforts to combat the growing global threat of dengue disease, including deployment of phase IIb vaccine trials, has continued to be hindered by uncertainty surrounding equitable immune responses of serotypes, relative viral fitness of vaccine vs naturally occurring strains, and the importance of altered immune environments due to natural delivery routes. Human infection models can significantly improve our understanding of the importance of certain phenotypic characteristics of viral strains, and inform strain selection and trial design. With human models, we can further assess the importance of the natural delivery route of DENV and/or the accompanying mosquito salivary milieu. Accordingly, we discuss the use of mosquitoes in such a human infection model with DENV, identify important considerations, and make preliminary recommendations for deployment of such a mosquito improved DENV human infection model (miDHIM). [ABSTRACT FROM AUTHOR]

The author comments on study related to the reevaluation of the role of Aedes albopictus mosquito in transmission of dengue which appeared in the 2015 issue of Journal of Infectious Diseases. Topics discussed include the complexity of vector-borne pathogen transmission cycles, the differences among dengue virus serotypes and comparison of Aedes aegypti and Aedes albopictus mosquitoes.