Resurgence of dengue in the Philippines

Abstract

The coronavirus disease 2019 (COVID-19) pandemic has significantly influenced the epidemiological landscape of various infectious diseases such as dengue. Dengue is an endemic disease in the Philippines, which showed a significant decline in the number of cases beginning in March 2020 due to the stringent public health measures implemented to curb COVID-19 cases. However, the easing of these restrictions subsequently led to a resurgence in dengue cases, as reported by the World Health Organization, with a notable increase compared to previous years. As the country navigates towards a post-pandemic phase, addressing the resurgence of dengue requires sustained efforts in vector control, surveillance, and healthcare preparedness. This article underscores the critical need for collaborative efforts among stakeholders to mitigate the resurgence of dengue while managing the ongoing recovery from the COVID-19 pandemic.

Key Words: Dengue; Dengue fever; COVID-19; Pandemic; SARS-CoV-2; Philippines

Core Tip: Maintaining robust public health measures implemented during the coronavirus disease pandemic and developing long-term strategies are crucial to mitigating the impact of dengue in the face of changing environmental and social dynamics. These measures not only address immediate outbreaks but also fortify the country's defenses against future infectious disease challenges as societal activities resume.

INTRODUCTION

The societal disruption brought by the coronavirus disease 2019 (COVID-19) pandemic indirectly affected the dynamics of various infectious diseases[1]. Dengue fever, considered a major public health problem in tropical countries such as the Philippines[2], is one of the diseases found to be significantly affected[1]. The decline in the incidence of dengue from March 2020 was strongly associated with public health and social measures implemented by governments to limit the spread of COVID-19[1]. These include limitations of social gatherings, cancellation of face-to-face classes, increased work-from-home setups, and community lockdowns. However, the recent lifting of lockdown restrictions and the gradual increase in human mobility resulted in a 191% increase in dengue cases in the Philippines[3].

Philippines against dengue

One of the Philippine government programs is the National Dengue Prevention and Control Program. This aims to eliminate dengue infection by properly implementing an integrated vector control approach and simultaneously reinforcing the diagnosis, management, and surveillance of dengue cases[4]. The 5S strategy, the 4 o’clock habit, and the dengue fast lane are the three main campaigns of the Department of Health to prevent dengue. The 5S strategy encourages communities to search and destroy breeding sites, employ self-protection measures, seek early consultation, support fogging in hotspot areas, and sustain adequate hydration. The 4 o’clock habit specifically refers to a stop, look, and listen approach, whereby one drops whatever is being done to search and destroy mosquito breeding sites. Dengue fast lanes in hospitals are put in place to ensure that suspected dengue patients are given immediate and proper medical intervention.

The government also introduced the Dengvaxia vaccine through mass immunization campaigns in April 2016 to protect children from hospitalization and severe dengue. However, these efforts turned out to be futile as new findings revealed that the dengue vaccine could result in a higher risk of severe dengue infection to recipients without prior dengue infection. The Dengvaxia controversy spawned a significant decline in vaccine confidence in the country. Nevertheless, the culmination of efforts against dengue infection has resulted in a significant decline in dengue cases in the country; with cases dropping from 430282 in 2019 to 59675 in 2020 and mortalities dropping from 1612 in 2019 to 231 in 2020[5]. The Department of Health claims that current activities and initiatives against dengue, such as updating the Dengue Manual of Operations, partnering with tertiary hospitals, and releasing administrative issuance lowered dengue incidence and mortalities[5]. However, this must be taken with a grain of salt because the emergence of COVID-19 in 2020 also significantly contributed to the observed decline in dengue cases.

LIMITATIONS IN DENGUE RESPONSE IN THE PHILIPPINES

Despite the progress reported by the Department of Health in terms of prevention and control of dengue during the COVID-19 pandemic, there is an alarming rise in dengue cases in the country at the moment. Its alarming resurgence uncovers the presence of various lapses and barriers to healthcare. While the COVID-19 pandemic laid bare the systemic healthcare inequities faced by millions of Filipinos, it has ironically concealed the omnipresent lapses in our dengue response. This is primarily due to the health and sociopolitical policies put in place to mitigate the spread of the COVID-19 pandemic. However, the improving pandemic response, the diminishing fears of COVID-19 infection, and our slow return to the old normal are slowly uncovering the gaps in our dengue response, paving the way for its subsequent re-emergence in the Philippines.

CONCLUSION

Mitigating the resurgence of dengue relies heavily on controlling the vector that transmits it. The key to the decline of dengue morbidity and mortality can be achieved by properly implementing existing strategies and incorporating various modifications necessary as the country transitions to a new normal. These strategies include: (1) Proper implementation of the enhanced 5S-Strategy against dengue to protect the population from mosquito bites and prevent the spread of dengue; (2) Increase public awareness and education through health campaigns; (3) Strengthening of current surveillance and reporting systems to track outbreaks, monitor disease trends, evaluate progress in morbidity and mortality reduction goals, and consequently guide decision-making for quicker responses and better resource allocation; (4) Promotion of vaccine confidence through a coordinated, transparent, evidence-based education, and behavioral intervention campaign; (5) Allocation of health resources to cheap and simple dengue diagnostics like nucleic acid amplification test-loop mediated isothermal amplification assay; (6) Supporting research and projects like the Wolbachia Project within Bicol-Center for Health Development to control dengue spread; and (7) Increasing capacity building by training healthcare providers, ensuring adequacy of medical supplies, and improving healthcare facilities’ capacity to diagnose and treat dengue promptly.

While we are recovering from the COVID-19 pandemic, we urge the government and relevant stakeholders to act hand in hand in transitioning to a new normal, without sacrificing all the progress that has already been made concerning dengue control and eradication.