By MATTHEW PARK (COL ‘19)
In the past half-decade, the world witnessed the re-emergence of a variety of infectious diseases that were once secluded to remote ecological niches. The resurfacing of these infectious pathogens has reminded the global community of the undeniable link between the emergence of infectious disease and socio-cultural determinants that disrupt complex ecological systems. Such factors include, among others, urban gentrification, international travel, and other artificial forces.
In 2014, the Saudi Arabian Ministry of Health, with the assistance from the United States Centers for Disease Control and Prevention (CDC), began an investigation of an outbreak of Middle East Respiratory Syndrome coronavirus (MERS-CoV), a pathogen known to cause severe acute respiratory illness in humans. A marked increase in the number of cases of MERS-CoV raised international speculation, prompting research not only into the molecular bases of pathogenesis, but also into clinical practice based in the affected countries. Subsequent observations highlighted the role of health care-associated transmission, primarily secondary human-to-human transmission and amplification via hospital-acquired infections. Similarly, inadequate implementation of a quarantine protocol and poor public health surveillance in South Korea are the primary causes of the largest case cluster of MERS outside of the Middle East. Over the past four years, MERS cases have continued to increase, especially with respect to the number of cases involving symptomatic individuals with travel history in Europe, the U.S.A., and Africa.
Not long after the re-emergence of MERS came the development of the Ebola epidemic in 2013. It began in the rural confines of villages in Guinea, and soon crossed into the neighboring countries of Sierra Leone and Liberia.
The Ebola epidemic revealed that the World Health Organization (WHO) was unprepared and incapable of both combating emerging infectious diseases with sufficient technical expertise and alerting the global community through a clear strategy to ensure accurate assessments of the outbreak. As stated in the report of the Harvard Global Health Institute and the London School of Hygiene & Tropical Medicine (Harvard-LSHTM) Independent Panel on the Global Response to Ebola, “the west African Ebola epidemic that began in 2013 exposed deep inadequacies in the national and international institutions responsible for protecting the public from the far-reaching human, social, economic, and political consequences of infectious diseases epidemics.” The report recommended the creation of a “transparent and politically protected WHO Standing Emergency Committee” and “an independent UN Accountability Commission” in order to conduct system-wide assessments of world responses to major disease outbreaks. These are perhaps the first steps that a now cautious global community – one that hesitantly acknowledged the magnitude of the Ebola epidemic – must take to overcome the obstacle of the past: inadequate international public health control measures.
In light of another outbreak — the Zika virus (ZIKV) — these changes to public health infrastructure are more imperative than ever. As with MERS, there is no readily available cure or vaccine for Ebola. Likewise, there is no commercial test to detect the exact strain of Zika virus. Long-term efforts to effectively combat ZIKV infections may prove to be difficult due to the clinical manifestations of infection: microcephaly in the newborn children of infected mothers, neurological complications, and as most recently discovered, sexual transmission.
Perhaps what is most puzzling is how the ZIKV, has managed to exhibit high rates of infectivity in such a short period of time. Though it is too early to determine significance of the current global health response, early epidemiological surveillance and human case studies led by the Brazilian Ministry of Health and the Salvador Health Authorities, as well as the immediate epidemiological alerts put forth by the Pan American Health Organization (PAHO) and the WHO, are important signs of an efficacious approach to combating the virus.