Genomic Sequencing of Dengue Virus Strains Associated with Papua New Guinean Outbreaks in 2016 Reveals Endemic Circulation of DENV-1 and DENV-2

Baseline assessment of front-line health system capacity in vector-borne disease surveillance and response in Papua New Guinea

International public health surveillance and timely response cannot exist without strengthened local surveillance and response systems. Supporting front-line healthcare workers to embed the use of innovative electronic health information systems into adaptable and sustainable processes within their contexts is essential for response to ongoing vector-borne diseases (VBDs) and emerging infectious diseases in resource-constrained settings such as Papua New Guinea (PNG). Baseline health service assessments were conducted at eight provinces to inform the implementation of the STRIVE-Tupaia platform. The STRIVE-Tupaia platform is an innovative electronic real-time data aggregation platform in PNG where healthcare workers are able to review, interpret and respond to febrile illness, molecular diagnostic and vector surveillance data to support evidence-based decision making. Baseline health service assessments involved semi-structured interviews and structured observations of facility procedures. Quantitative data were analyzed using Microsoft Excel, while the qualitative data were thematically coded in NVivo12 (QSR International Pty Ltd). A deductive analysis focussed on the health systems barriers and enablers using the WHO's seven component health systems framework. An inductive analysis explored these impacts for vector-borne disease services specifically. Results indicated barriers to VBD reporting, notification and response including limited training, infrastructure challenges, overstretched workforce and limited governance support. Key learnings from STRIVE's baseline health facility assessments have been used to inform the implementation of the STRIVE-Tupaia platform and improve health care workers routine reporting, notification and response to vector-borne diseases in Papua New Guinea.

Web Visualization for Spatiotemporal Genomic Epidemiology, Annotation, and Mutation Dynamics of Orthohantavirus hantanense Using Nextstrain

The phylogeographic inference approach aims to connect genomic data with epidemiology to understand the spread and evolution of pathogens using visualization of spatiotemporal reconstructions. Orthohantavirus hantanense (HTNV), the causative agent of hemorrhagic fever with renal syndrome (HFRS), represents a significant global public health concern. Here, we introduce a localized Nextstrain platform for HTNV, offering a comprehensive resource for facilitating spatiotemporal genomic surveillance and the study of evolutionary dynamics of viral genomes. Nextstrain enables web-based visualization and simple sharing of graphic and numeric data through unique web addresses. The Nextstrain build for HTNV stands out for its user-friendly interface and is readily accessible online at https://nextstrain.org/community/KU-MV/Hantavirus. This study provides valuable insights into genomic surveillance, viral phylodynamics, and the evolutionary history of orthohantaviruses for the development of public health policies against endemic HFRS outbreaks.

Whole Genome Sequencing of DENV-2 isolated from Aedes aegypti mosquitoes in Esmeraldas, Ecuador. Genomic epidemiology of genotype III Southern Asian-American in the country

Ecuador is a tropical country reporting Dengue virus (DENV) outbreaks with areas of hyperendemic viral transmission. Entomo-virological surveillance and monitoring effort conducted in the Northwestern border province of Esmeraldas in April 2022, five pools of female Aedes aegypti mosquitoes from a rural community tested positive for DENV serotype 2 by RT-qPCR. One pool was sequenced by Illumina MiSeq, and it corresponded to genotype III Southern Asian-American. Comparison with other genomes revealed genetic similarity to a human DENV genome sequenced in 2021, also from Esmeraldas. Potential introduction events to the country could have originated from Colombia, considering the vicinity of the collection sites to the neighboring country and high human movement. The inclusion of genomic information complements entomo-virological surveillance, providing valuable insights into genetic variants. This contribution enhances our understanding of Dengue virus (DENV) epidemiology in rural areas and guides evidence-based decisions for surveillance and interventions.

Changing Ecotypes of Dengue Virus 2 Serotype in Nigeria and the Emergence of Cosmopolitan and Asian I Lineages, 1966-2019

Dengue virus (DENV) is a leading mosquito-borne virus with a wide geographical spread and a major public health concern. DENV serotype 1 (DENV-1) and serotype 2 (DENV-2) were first reported in Africa in 1964 in Ibadan, Nigeria. Although the burden of dengue is unknown in many African countries, DENV-2 is responsible for major epidemics. In this study, we investigated the activities of DENV-2 to determine the circulating strains and to appraise the changing dynamics in the epidemiology of the virus in Nigeria. Nineteen DENV-2 sequences from 1966-2019 in Nigeria were retrieved from the GenBank of the National Center of Biotechnology Information (NCBI). A DENV genotyping tool was used to identify the specific genotypes. The evolutionary history procedure was performed on 54 DENV-2 sequences using MEGA 7. There is a deviation from Sylvatic DENV-2 to other genotypes in Nigeria. In 2019, the Asian I genotype of DENV-2 was predominant in southern Edo State, located in the tropical rainforest region, with the first report of the DENV-2 Cosmopolitan strain. We confirmed the circulation of other non-assigned genotypes of DENV-2 in Nigeria. Collectively, this shows that DENV-2 dynamics have changed from Sylvatic transmission reported in the 1960s with the identification of the Cosmopolitan strain and Asian lineages. Sustained surveillance, including vectorial studies, is required to fully establish the trend and determine the role of these vectors.