A recent study published in the journal Pediatric Research reviewed emerging and re-emerging viral diseases.
Increased Prevalence of Viral Diseases
Multiple epidemics and pandemics have occurred in the past two decades due to novel and known viruses. Global cooperation in research, surveillance, and preparedness measures is urgently required to address existing and future outbreaks. The World Health Organization (WHO) introduced the Disease X concept in 2018 to develop a preparedness planning framework for unpredictable events.
Study: Emerging and re-emerging pediatric viral diseases: a continuing global challenge
The COVID-19 Pandemic and Disease X
Disease X represents a hypothetical pathogen that could trigger an epidemic or pandemic in the future. The coronavirus disease 2019 (COVID-19) pandemic caused an unprecedented global emergency. While preparations for Disease X led to calls for action and recommendations, public health institutions, which were underfunded for a long time, were slow to react. As such, there have been over 771.8 million COVID-19 cases and 6.9 million deaths to date.
Although the global emergency of COVID-19 ended in May 2023, there is a pressing need to continue to develop more effective strategies for emerging and re-emerging viral infections. Understanding the trends of these diseases and the state of global prevention and control efforts is necessary to address the ongoing public health challenge. As such, the present study reviewed emerging and re-emerging viral diseases, focusing on pediatric populations.
Impact on Pediatric Health
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of COVID-19, was first reported in late 2019. COVID-19 appears to have a low mortality rate in pediatric populations relative to adults but a high multifactorial morbidity. Specifically, multisystem inflammatory syndrome in children (MIS-C) is a severe complication, manifesting four-to-six weeks after mild or asymptomatic COVID-19.
Moderna’s mRNA-1273 and Pfizer’s BNT162b2 vaccines have been safe and effective in children under 18 to prevent infection, hospitalization, severe illness, MIS-C, and death.
Zika Virus Resurgence and Its Consequences
Zika virus (ZIKV) is an arbovirus (mosquito-borne), first detected in Uganda in the 1940s. The virus has spread worldwide due to the ecology of its vectors (Aedes aegypti and Aedes albopictus ).
There were more than 40,000 cases of ZIKV in the Americas in 2022. Studies have linked maternal ZIKV infection during the first two trimesters to microcephaly. Management of acute ZIKV cases is supportive, and evidence-based therapies are lacking. The mechanisms of microcephaly and other defects related to congenital ZIKV syndrome are poorly defined. Further, vaccines and therapeutics for ZIKV are under various stages of development.
Viral Threats: From Nipah to Mpox
Nipah virus (NiV) was first isolated after an outbreak in Malaysia in 1999. NiV has a high mortality rate (> 70%) and has been a research priority, given its pandemic potential. A study on NiV transmission in Bangladesh highlighted that children aged ≤ 14 were the most affected, with the case fatality rate estimated at around 80%.
Mpox, previously known as monkeypox, is a zoonotic disease caused by the mpox virus. The virus was first isolated in 1958. The mpox case burden has been historically disproportionate in children. The largest mpox outbreak occurred in 2022, resulting in > 86,000 cases worldwide, predominantly among men who have sex with men. Although pediatric cases were rare in 2022, prior reports suggest a higher risk of severe illness in children.
Challenges in Eradicating Endemic Viruses
Measles virus (MV) is highly contagious and spreads through respiratory droplets. Vaccination or infection offers lifetime immunity. Efforts to achieve MV eradication have been a global priority for decades. However, the number of MV cases and deaths has been steadily increasing since 2016, mainly due to the failure to vaccinate, with many deaths recorded in children under five years.
Children with weakened immune systems and malnutrition are at an increased risk of severe illness and death. The resurgence of measles and the failure to achieve MV eradication emphasize the need for continued investment in surveillance and vaccination efforts. Ebola virus (EBOV) causes the Ebola virus disease. EBOV was isolated in 1976 during separate outbreaks of viral hemorrhagic fever in Sudan and the Democratic Republic of Congo (DRC).
At the time, the case fatality rate was 53% in Sudan and 88% in DRC. EBOV outbreaks were mostly recorded in Central Africa until 2013. The largest outbreak occurred between 2013 and 2016, resulting in 28,000 cases and 11,000 deaths. Although children represent a minor proportion of cases, the EBOV incubation period is shorter, with an increased mortality risk in children under five.
Chikungunya virus (CHIKV) is an arbovirus that causes chikungunya fever, a febrile disease associated with severe arthritis, arthralgia, maculopapular rash, and headache. It was first described in southern Tanzania in 1952-53. CHIKV infection is more frequently associated with severe disease than Dengue. The neurologic, hematologic, and cutaneous manifestations of the disease are more broad and common in children than in adults.
Dengue virus (DENV) is an arbovirus causing dengue fever. Re-infection with a different serotype of DENV results in severe illness associated with dengue hemorrhagic fever and dengue shock syndrome through antibody-dependent enhancement. The incidence of Dengue is higher among young individuals and children. Treatment for Dengue is supportive, with no approved antivirals or therapies.
Rising Concerns: H5N1 and the Impact of Climate Change
The global spread of a highly pathogenic avian influenza H5N1 virus has led to the deaths and culling of millions of wild birds and poultry since 2022. Moreover, the increasing spillover of H5N1 into mammals raises speculations over the emergence of a more transmissible virus. Furthermore, the dissemination of misinformation and disinformation in the globally interconnected society can compound the threat.
Additionally, climate change has disproportionately impacted underserved communities with limited resources, widening the gaps in health inequity. Addressing these challenges requires international cooperation and partnerships that adopt the one health-planetary health approach, which integrates the health of humans, animals, and ecosystems to ensure equitable resource distribution and enhanced resilience in global communities and tackle the disproportionate burden of viral diseases.
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