Cosmopolitan A1 lineage of dengue virus serotype 2 is circulating in Pakistan: A study from 2017 dengue viral outbreak

Serotype and genomic diversity of dengue virus during the 2023 outbreak in Pakistan reveals the circulation of genotype III of DENV-1 and cosmopolitan genotype of DENV-2

Dengue, a mosquito-borne viral disease, poses a significant public health challenge in Pakistan, with a significant outbreak in 2023, prompting our investigation into the serotype and genomic diversity of the dengue virus (DENV). NS-1 positive blood samples from 153 patients were referred to the National Institute of Health, Pakistan, between July and October 2023. Among these, 98 (64.1%) tested positive using multiplex real-time PCR, with higher prevalence among males (65.8%) and individuals aged 31-40. Serotyping revealed DENV-1 as the predominant serotype (84.7%), followed by DENV-2 (15.3%). Whole-genome sequencing of 18 samples (DENV-1 = 17, DENV-2 = 01) showed that DENV-1 (genotype III) samples were closely related (>99%) to Pakistan outbreak samples (2022), and approx. > 98% with USA (2022), Singapore and China (2016), Bangladesh (2017), and Pakistan (2019). The DENV-2 sequence (cosmopolitan genotype; clade IVA) shared genetic similarity with Pakistan outbreak sequences (2022), approx. > 99% with China and Singapore (2018-2019) and showed divergence from Pakistan sequences (2008-2013). No coinfection with dengue serotypes or other viruses were observed. Comparisons with previous DENV-1 sequences highlighted genetic variations affecting viral replication efficiency (NS2B:K55R) and infectivity (E:M272T). These findings contribute to dengue epidemiology understanding and underscore the importance of ongoing genomic surveillance for future outbreak responses in Pakistan.

Genomic Characterization of Dengue Virus Outbreak in 2022 from Pakistan

Pakistan, a dengue-endemic country, has encountered several outbreaks during the past decade. The current study aimed to explore the serotype and genomic diversity of dengue virus responsible for the 2022 outbreak in Pakistan. From August to October 2022, NS-1 positive blood samples (n = 343) were collected from dengue patients, among which, (85%; n = 293) were positive based on RT-PCR. In terms of gender and age, dengue infection was more prevalent in male patients (63%; n = 184), with more adults (21-30 years; n = 94) being infected. The serotyping results revealed DENV-2 to be the most predominant serotype (62%; n = 183), followed by DENV-1 (37%; n = 109) and DENV-3 (0.32%; n = 1). Moreover, a total of 10 samples (DENV-2; n = 8, DENV-1; n = 2) were subjected to whole-genome sequencing. Among these, four were collected in early 2022, and six were collected between August and October 2022. Phylogenetic analysis of DENV-2 sequenced samples (n = 8) revealed a monophyletic clade of cosmopolitan genotype IVA, which is closely related to sequences from China and Singapore 2018, and DENV-1 samples (n = 2) show genotype III, which is closely related to Pakistan isolates from 2019. We also reported the first whole genome sequence of a coinfection case (DENV1-DENV2) in Pakistan detected through a meta-genome approach. Thus, dengue virus dynamics reported in the current study warrant large-scale genomic surveillance to better respond to future outbreaks.

A cross-sectional study to assess the epidemiological situation and associated risk factors of dengue fever; knowledge, attitudes, and practices about dengue prevention in Khyber Pakhtunkhwa Province, Pakistan

Background

Dengue fever has been responsible for around 12 countrywide large outbreaks in Pakistan, resulting in 286,262 morbidities and 1,108 deaths. Khyber Pakhtunkhwa (KP) is the most recently impacted province. This study aimed to investigate the molecular, epidemiological, and potential elements that contribute to increasing dengue transmission patterns, and knowledge, attitude, and practice (KAP) toward dengue in KP province.

Method

This cross-sectional community-based study was conducted (June-December, 2021) in two phases. Phase I involved the epidemiological (n = 5,242) and molecular analysis of DENV in 500 randomly collected blood samples of the 2021 dengue outbreak in KP. Phase II focused on assessing dengue-KAP levels in healthy communities (n = 14,745, aged >18 years), adopting a cross-sectional clustered multistage sampling in eight districts (dengue-hotspot vs. non-hotspot) of KP. Chi-square tests and logistic regression analysis were applied.

Results

Peshawar district had the highest dengue cases (60.0%) associated with the predominant co-circulation of DENV-2 (45.8%) and DENV-3 (50.4%) serotypes. A rise in cases was reported in October (41.8%) followed by September (27.9%) and August (14.4%; p < 0.001). Males (63.7%, p < 0.001) and individuals aged 16–30 years (37.0%, p < 0.001) were highly affected. General workers (18.0%), families with a monthly income of 10,000–20,000 Pak rupees (50.5%), unmarried (71.0%), uneducated (31%), families with higher human density (>10 individuals per household), and those (29.0%) who faced power outages for more than 7/24 h were the most affected. Moreover, co-morbidities like renal failure and bronchial asthma were associated with disease severity. A community survey on KAP revealed that an average of 74, 60, and 43% of the participants demonstrated good knowledge, attitudes, and dengue preventive practices, respectively.

Conclusion

Multiple poor socioeconomic elements are influencing dengue fever transmission in the province. Higher KAP levels may explain the low frequency of dengue in non-hotspot districts. Our study emphasizes the need for effective and long-term public health education, strengthened vector surveillance, and expanded laboratory capacity for better diagnosis and management of dengue cases to better predict the burden and seasonality of disease in the country.

Emerging Mosquito-Borne Viruses Linked to Aedes aegypti and Aedes albopictus: Global Status and Preventive Strategies

Emerging mosquito-borne viruses continue to cause serious health problems and economic burden among billions of people living in and near the tropical belt of the world. The highly invasive mosquito species Aedes aegypti and Aedes albopictus have successively invaded and expanded their presence as key vectors of Chikungunya virus, dengue virus, yellow fever virus, and Zika virus, and that has consecutively led to frequent outbreaks of the corresponding viral diseases. Of note, these two mosquito species have gradually adapted to the changing weather and environmental conditions leading to a shift in the epidemiology of the viral diseases, and facilitated their establishment in new ecozones inhabited by immunologically naive human populations. Many abilities of Ae. aegypti and Ae. albopictus, as vectors of significant arbovirus pathogens, may affect the infection and transmission rates after a bloodmeal, and may influence the vector competence for either virus. We highlight that many collaborating risk factors, for example, the global transportation systems may result in sporadic and more local outbreaks caused by mosquito-borne viruses related to Ae. aegypti and/or Ae. albopictus. Those local outbreaks could in synergy grow and produce larger epidemics with pandemic characters. There is an urgent need for improved surveillance of vector populations, human cases, and reliable prediction models. In summary, we recommend new and innovative strategies for the prevention of these types of infections.

Use of public health emergency operations center (PH-EOC) and adaptation of incident management system (IMS) for efficient inter-sectoral coordination and collaboration for effective control of Dengue fever outbreak in Pakistan - 2019

Public Health Emergency Operations Center (PH-EOC) and Incident Management System (IMS) provides a platform for inter-sectoral coordination, and collaboration to enhance efficiency of response activities and help in effective control of disease outbreaks. Dengue fever (DF) is an emerging serious public health threat with a potential to transform into a public health emergency. Pakistan faced a heavy outbreak of Dengue fever (DF) from August to December 2019. National Institute of Health (NIH), Islamabad activated its Public Health Emergency Operations Center (PH-EOC) with an objective to implement principles and practices of IMS for control of the outbreak. The challenges during inter-sectoral collaboration for response activities were also identified. PH-EOC was activated on 16th September 2019, and remained operational for next 81 days till 05th December 2019. Incident management structure, incident action plan (IAP), and risk communication plan was developed and executed during this phase. Daily morning and evening meetings were held during all operational days. Federal and provincial health departments, district health offices (DHO), and government/private hospitals were coordinated for collection of the data pertaining to Dengue confirmed cases and deaths. As of 05th December 2019, a total of 52,877 confirmed Dengue cases were reported from all across Pakistan with maximum cases reported from Rawalpindi and Islamabad collectively i.e. 20,988 (40%), followed by Karachi 14,768 (28%), and Peshawar 2,699 (5%), while AJK reported 1,690 (3%). A total of 92 deaths happened all across Pakistan, out of which 43 (47%) happened in Karachi, 23 (25%) in Rawalpindi, and 22 (24%) in Islamabad. The response was coordinated through NIH based PH-EOC, but was carried out by relevant federal and provincial district health offices, vector surveillance programs, dengue control programs and sanitation departments respectively. As a part of response plan, vector surveillance, larva source management, and insecticidal spraying i.e. both fogging and indoor residual spraying activities were carried out in hotspots or the areas where confirmed cases were reported. Sanitation departments daily reported the removal of additional 80-100 ton of solid waste from hotspot areas. Hospitals were coordinated for reporting of isolation of DF patients and provision of quality clinical management for admitted patients. The International Federation for Red Cross/Crescent conducted community awareness, and covered 28,800 households in affected areas of Islamabad. Conversely, the DF outbreak was controlled 02-03 weeks ahead of previous years trends. All the coordinated activities were incorporated in a daily situation report (SitRep) and this was widely distributed among all the stakeholders through emails. Additionally, the data was displayed on the dashboard in PH-EOC. The data dashboard at PH-EOC served as an information management hub that visually mapped, tracked, analyzed, and displayed clusters of DF cases and hotspots. Accordingly, SitRep substantiated as the main reporting tool to monitor response activities initiated by rapid response teams at the national and subnational level. The inter-sectoral coordinating efforts made among concerned line departments resulted in a timely response leading to effective handling of a national public health threat. The information distilled from this experience was that the early and judicious activation of PH-EOC with adaptation of IMS under decision making leadership resulted in a well-managed and prompt response executed by different departments/stakeholders, and effective control of the outbreak before its transformation into a public health event/emergency of national or international concern.

Stopping Membrane-Enveloped Viruses with Nanotechnology Strategies: Toward Antiviral Drug Development and Pandemic Preparedness

Membrane-enveloped viruses are a leading cause of viral epidemics, and there is an outstanding need to develop broad-spectrum antiviral strategies to treat and prevent enveloped virus infections. In this review, we critically discuss why the lipid membrane surrounding enveloped virus particles is a promising antiviral target and cover the latest progress in nanotechnology research to design and evaluate membrane-targeting virus inhibition strategies. These efforts span diverse topics such as nanomaterials, self-assembly, biosensors, nanomedicine, drug delivery, and medical devices and have excellent potential to support the development of next-generation antiviral drug candidates and technologies. Application examples in the areas of human medicine and agricultural biosecurity are also presented. Looking forward, research in this direction is poised to strengthen capabilities for virus pandemic preparedness and demonstrates how nanotechnology strategies can help to solve global health challenges related to infectious diseases.

Dengue outbreak 2018 in district Shangla KPK; clinical features and laboratory markers of dengue virus infection

Aim: To analyze and quantify the 2018 dengue outbreak which occurred in district Shangla, Pakistan. Materials & methods: 964 suspected dengue samples were collected and examined for clinical manifestation and laboratory markers. Results: In all, 375 suspected cases were confirmed with dengue virus infection using nonstructural protein 1 (NS1) antigen, immunoglobulin M (IgM) & Immunoglobulin G (IgG) antibodies and real-time PCR whereas PCR was 92.2% sensitive. The most prevalent serotype was dengue virus 3 (60.26%). The male/female ratio was 1.84 and the most highly affected tehsil was Alpuri. The most affected age group was 16–40 years (70.4%). A significant number of cases were reported in September (48.54%). Conclusion: Recurrence of the dengue outbreaks in the study area could alarmingly increase the mortality rate, therefore, proper measures are essential to control dengue epidemics in the future.

Current status of dengue virus, poliovirus, and chikungunya virus in Pakistan

Epidemics of infectious diseases especially dengue virus (DENV), chikungunya virus (CHIKV), and poliovirus are the leading cause of mortality and morbidity in Pakistan. Risks associated with these outbreaks have drastic effects on the healthcare infrastructure and economy of the country. This report provides the current status of DENV, poliovirus, and CHIKV in Pakistan and further highlights the measures needed to control these infections.