Multisectoral Approach to Address Chikungunya Outbreaks Driven by Human Mobility: A Systematic Review and Meta-Analysis

Assessing chikungunya's economic burden and impact on health-related quality of life: Two systematic literature reviews

BACKGROUND

Chikungunya virus (CHIKV), transmitted through Aedes mosquitoes, has witnessed a global surge in distribution and outbreaks, posing a significant public health threat. This study conducted two systematic literature reviews (SLRs) to examine the socio-economic burden associated with chikungunya.

METHODS

Two SLRs were conducted employing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 (PRISMA 2020) standards. The SLRs covered electronic databases, grey literature, and bibliographic searches. Inclusion criteria were guided by the PICOS (Population, Intervention, Comparator, Outcomes, Study type) framework.

FINDINGS

A total of 34 studies on cost and resource use and 37 studies on health-related quality of life (HRQoL) were included. Direct costs, driven by hospitalization, consultations, diagnostics, and drugs, were frequently reported, with significant variability across studies. Indirect costs, mainly attributed to absenteeism, constituted a substantial portion of the total economic burden. HRQoL studies consistently revealed high pain levels and diminished physical functioning among chikungunya patients, particularly in chronic cases, where these impacts persisted for months to years.

CONCLUSIONS

This study highlights the significant economic and public health impact of chikungunya, driven by high treatment costs, productivity losses, and chronic disability. Despite the severity of the disease, limited awareness regarding the severity and economic burden, particularly in resource-limited regions, persists. Our findings underscore the need for targeted public health strategies, standardized management approaches, and increased research to better understand the socio-economic burden of the disease and inform effective interventions.

Emerging Arboviral Diseases in Pakistan: Epidemiology and Public Health Implications

Arboviruses pose significant public health challenges globally, particularly in Pakistan, where deforestation, climate change, urbanization, inadequate sanitation, and natural disasters have all contributed to the spread of mosquito-borne flavivirus diseases like dengue fever. The lack of a thorough national surveillance system has made it difficult to determine the extent and distribution of these diseases. Concern has been raised by recent outbreaks of West Nile virus (WNV) and chikungunya (CHIKV) epidemics, which may lead to Zika virus (ZIKV) outbreaks in the future. Additionally, hospital-based surveillance has detected the Japanese encephalitis virus (JEV) in the region. Evidence also points to the presence of additional arboviruses in healthy populations, such as the Karshi virus (KSV), Tamdy virus (TAMV), Crimean-Congo hemorrhagic fever virus (CCHFV), and severe fever with thrombocytopenia syndrome virus (SFTSV). This review aims to address the risk factors linked to these diseases, provide specific policy recommendations for efficient disease prevention and control, and describe the epidemiological trends of these diseases in Pakistan while emphasizing the critical need for improved surveillance and thorough epidemiological investigations.

The Impacts of Climate Change on the Emergence and Reemergence of Mosquito-Borne Diseases in Temperate Zones: An Umbrella Review Protocol

INTRODUCTION

Mosquito-borne diseases represent a global public health concern and are responsible for over 700 000 deaths globally every year. Additionally, many mosquito species have undergone a dramatic global expansion due to various factors, including climate change, and forecasts indicate that mosquito populations will persist in dispersing beyond their present geographic range, namely in temperate climates. The research literature on this topic has grown in recent years, including some systematic evidence synthesis. However, to provide a comprehensive overview of this growing literature needed for policy action, a summary of this evidence, including existing systematic reviews, is required. This study aims to undertake an umbrella review that explores the impacts of climate change on the emergence and reemergence of diseases transmitted by mosquitoes in temperate zones and the publication of the protocol is a fundamental step to ensure the credibility, transparency and reproducibility of this research.

METHODS AND ANALYSIS

Studies published in scientific journals indexed by PubMed, EMBASE, Cochrane Library, Epistemonikos, and Web of Science Core Collection to be included in this umbrella review will meet the following criteria: the topic of study (climate change and mosquito-borne diseases), regions (temperate zones), study designs (systematic reviews and meta-analysis), language (any) and date (since inception until December 31st, 2023). Titles and abstracts from selected articles will be evaluated by two authors independently and any discrepancy will be resolved through consensus or, if not possible, through a third author. The data will be extracted, and the risk of bias will be evaluated. The quality of the methodology of the included reviews will be assessed using AMSTAR 2. A narrative synthesis will examine the included systematic reviews. The quality of evidence for all outcomes will be judged using the Grading of Recommendations Assessment, Development and Evaluation working group methodology.

Risk Index of Regional Infection Expansion of COVID-19: Moving Direction Entropy Study Using Mobility Data and Its Application to Tokyo

BACKGROUND

Policies, such as stay home, bubbling, and stay with your community, recommending that individuals reduce contact with diverse communities, including families and schools, have been introduced to mitigate the spread of the COVID-19 pandemic. However, these policies are violated if individuals from various communities gather, which is a latent risk in a real society where people move among various unreported communities.

OBJECTIVE

We aimed to create a physical index to assess the possibility of contact between individuals from diverse communities, which serves as an indicator of the potential risk of SARS-CoV-2 spread when considered and combined with existing indices.

METHODS

Moving direction entropy (MDE), which quantifies the diversity of moving directions of individuals in each local region, is proposed as an index to evaluate a region's risk of contact of individuals from diverse communities. MDE was computed for each inland municipality in Tokyo using mobility data collected from smartphones before and during the COVID-19 pandemic. To validate the hypothesis that the impact of intercommunity contact on infection expansion becomes larger for a virus with larger infectivity, we compared the correlations of the expansion of infectious diseases with indices, including MDE and the densities of supermarkets, restaurants, etc. In addition, we analyzed the temporal changes in MDE in municipalities.

RESULTS

This study had 4 important findings. First, the MDE values for local regions showed significant invariance between different periods according to the Spearman rank correlation coefficient (>0.9). Second, MDE was found to correlate with the rate of infection cases of COVID-19 among local populations in 53 inland regions (average of 0.76 during the period of expansion). The density of restaurants had a similar correlation with COVID-19. The correlation between MDE and the rate of infection was smaller for influenza than for COVID-19, and tended to be even smaller for sexually transmitted diseases (order of infectivity). These findings support the hypothesis. Third, the spread of COVID-19 was accelerated in regions with high-rank MDE values compared to those with high-rank restaurant densities during and after the period of the governmental declaration of emergency (P<.001). Fourth, the MDE values tended to be high and increased during the pandemic period in regions where influx or daytime movement was present. A possible explanation for the third and fourth findings is that policymakers and living people have been overlooking MDE.

CONCLUSIONS

We recommend monitoring the regional values of MDE to reduce the risk of infection spread. To aid in this monitoring, we present a method to create a heatmap of MDE values, thereby drawing public attention to behaviors that facilitate contact between communities during a highly infectious disease pandemic.

Developing brain under renewed attack: viral infection during pregnancy

Living in a globalized world, viral infections such as CHIKV, SARS-COV-2, and ZIKV have become inevitable to also infect the most vulnerable groups in our society. That poses a danger to these populations including pregnant women since the developing brain is sensitive to maternal stressors including viral infections. Upon maternal infection, the viruses can gain access to the fetus via the maternofetal barrier and even to the fetal brain during which factors such as viral receptor expression, time of infection, and the balance between antiviral immune responses and pro-viral mechanisms contribute to mother-to-fetus transmission and fetal infection. Both the direct pro-viral mechanisms and the resulting dysregulated immune response can cause multi-level impairment in the maternofetal and brain barriers and the developing brain itself leading to dysfunction or even loss of several cell populations. Thus, maternal viral infections can disturb brain development and even predispose to neurodevelopmental disorders. In this review, we discuss the potential contribution of maternal viral infections of three relevant relative recent players in the field: Zika, Chikungunya, and Severe Acute Respiratory Syndrome Coronavirus-2, to the impairment of brain development throughout the entire route.

Safety and immunogenicity of PXVX0317, an aluminium hydroxide-adjuvanted chikungunya virus-like particle vaccine: a randomised, double-blind, parallel-group, phase 2 trial

BACKGROUND

Chikungunya virus (CHIKV) disease is an ongoing public health threat. We aimed to evaluate the safety and immunogenicity of PXVX0317, an aluminium hydroxide-adjuvanted formulation of a CHIKV virus-like particle (VLP) vaccine.

METHODS

This randomised, double-blind, parallel-group, phase 2 trial was conducted at three clinical trial centres in the USA. Eligible participants were healthy CHIKV-naïve adults aged 18-45 years. Participants were stratified by site and randomly assigned (1:1:1:1:1:1:1:1) to one of the eight vaccination groups using a block size of 16. Group 1 received two doses of unadjuvanted PXVX0317 28 days apart (2 × 20 μg; standard); all other groups received adjuvanted PXVX0317: groups 2-4 received two doses 28 days apart (2 × 6 μg [group 2], 2 × 10 μg [group 3], or 2 × 20 μg [group 4]; standard); group 4 also received a booster dose 18 months after the first active injection (40 μg; standard plus booster); groups 5-7 received two doses 14 days apart (2 × 6 μg [group 5], 2 × 10 μg [group 6], or 2 × 20 μg [group 7]; accelerated); and group 8 received one dose (1 × 40 μg; single). The primary endpoint was the geometric mean titre of anti-CHIKV neutralising antibody on day 57 (28 days after the last vaccination), assessed in the immunogenicity-evaluable population. Additionally, we assessed safety. This trial is registered at ClinicalTrials.gov, NCT03483961.

FINDINGS

This trial was conducted from April 18, 2018, to Sept 21, 2020; 468 participants were assessed for eligibility. Of these, 415 participants were randomly assigned to eight groups (n=53 in groups 1, 5, and 6; n=52 in groups 2 and 8; n=51 in groups 3 and 7; and n=50 in group 4) and 373 were evaluable for immunogenicity. On day 57, serum neutralising antibody geometric mean titres were 2057·0 (95% CI 1584·8-2670·0) in group 1, 1116·2 (852·5-1461·4; p=0·0015 vs group 1 used as a reference) in group 2, 1465·3 (1119·1-1918·4; p=0·076) in group 3, 2023·8 (1550·5-2641·7; p=0·93) in group 4, 920·1 (710·9-1190·9; p<0·0001) in group 5, 1206·9 (932·4-1562·2; p=0·0045) in group 6, 1562·8 (1204·1-2028·3; p=0·14) in group 7, and 1712·5 (1330·0-2205·0; p=0·32) in group 8. In group 4, a booster dose increased serum neutralising antibody geometric mean titres from 215·7 (95% CI 160·9-289·1) on day 547 to 10 941·1 (7378·0-16 225·1) on day 575. Durability of the immune response (evaluated in groups 1, 4, and 8) was shown up to 2 years. The most common solicited adverse event was pain at the injection site, reported in 12 (23%) of 53 participants who received the unadjuvanted vaccine (group 1) and 111 (31%) of 356 who received the adjuvanted vaccine. No vaccine-related serious adverse events were reported.

INTERPRETATION

PXVX0317 was well tolerated and induced a robust and durable serum neutralising antibody immune response against CHIKV up to 2 years. A single 40 μg injection of adjuvanted PXVX0317 is being further investigated in phase 3 clinical trials (NCT05072080 and NCT05349617).

FUNDING

Emergent BioSolutions.