Pandemic and Epidemic Disease Prevention – Zika virus.

Penny Ou

The 2016 Summer Olympics scheduled to take place in Rio de Janeiro, Brazil, from August 5 to August 21 has raised concerns to the spread of disease and future health of the general population worldwide, as the mosquito-borne virus Zika sweeps its way over countries and territories in the Americas. Throughout the course of history, diseases have had decisive influences on the development of mankind. Before the industrial revolution, infectious diseases were deadly, but could only cause damage in a specific area. In the tightly connected world we live in today however, infectious diseases are not only a concern to the local region in which a virus originates, but also a serious threat to human health on a global scale. Related organizations must keep up with the ever changing threats around us.

 

Background

 

The Zika fever has been a concerning issue since its wide-scaled outbreak in 2013 to this present day. Scientists first identified this virus in 1947, on monkeys in the Zika forest of Uganda, and human cases were later confirmed in the 1960s to 1980s in equatorial regions of Asia and Africa; fortunately no deaths were reported. In 2007, the first outbreak of Zika virus infected an estimated 73% of residents on the Pacific Island of Yap, and from 2013 on, the virus has spread from 4 other groups in the Pacific Islands to Brazil. As of 2016, cases have been reported across the globe in areas where vectors are found.

The virus belongs to the virus family Flaviviridae, which indicates typical transmissions are done primarily through mosquitoes or other arthropod vectors, and is related to yellow fever, Japanese encephalitis, and dengue fever. Uniquely, person-to-person transmission is also possible for the Zika virus, as cases of sexual transmission and via blood transfusion have been documented in areas where locally transmitted cases have not been reported. Symptoms generally last for seven days, and typically resemble a very weak form of dengue fever, which include fever, red eyes, joint pain, and headache. These mild and nonspecific indications pose particular challenges to the surveillance of the virus and cause complications in disease control.

Although severe cases that require hospitalization are uncommon and deaths are rare, potential long-term dangers for infected populations are being unraveled with further research and understanding of this disease in the recent 2015-2016 outbreak. Since the outbreak in 2013, Brazil, El Salvador, Mexico and other areas have reported unusual increase in the number of cases of microcephaly among newborns and individuals with Guillain- Barre syndrome (GBS). Situation reports published on June 16th 2016 by the Emergency Committee of WHO have confirmed that the Zika virus is a cause of microcephaly and GBS and experts believe the virus is likely to cause additional neurological problems that will become apparent as infected children develop. Until further information can be uncovered, the extent of damage is still unknown.

Response Actions

 

On February 14th 2016, WHO launched the global Strategic Response Framework and Joint Operations Plan, acknowledging the importance of coordination amongst key responders such as the UN, NGOs, and other researchers on this global issue. A revised Zika Strategic Response Plan was announced on June 16th with added information on the situation at hand. The new response strategy has moved away from an emergency framework to a longer term programmatic approach, and includes finalizing the definition of Zika virus and its complications, developing relevant risk communication, behavior change and materials, and also focuses on management and surveillance of infected and high risk populations. Towards transmission control, the approach is to implement integrated vector management (IVM) through efficient use of resources in applications of various control methods (Sterile Insect Technique (SIT)); adaption of interventions to local vector ecology and epidemiology will be closely evaluated for evidence-based decision-making.

The Centers for Disease Control and Prevention (CDC) published a Draft Interim Response Plan on June 14th to announce protocol procedures that take action in the continental United States and Hawaii, in response to locally acquired cases of Zika infection, as well as sexually transmitted and Travel- associated infections found in the United States before locally transmitted cases were detected. Using observations from historical locally-acquired cases of related infections such as dengue, the CDC recommends applying surveillance for human-related illnesses rather than surveillance for infected mosquitoes, as investigations have shown that human illness surveillance is more informative and sensitive. Guidelines to ensuring blood safety and availability were promoted with recommendations from the Food and Drug Administration (FDA) and Council of State and Territorial Epidemiologists (CSTE), along with other action steps to communication, vector control, and patient support.

Other regional organizations have yet to establish strategic plans in specific response to the Zika virus, given the un-likeliness of the virus's nature to spread in areas not optimal to the primary vector. Precautions for non-local transmission are acknowledged in existing work plans related to blood safety, and sexually transmitted disease (STD) prevention. Listed in the Health Asia-Pacific 2020 Roadmap published in 2014 are plans to invest in the prevention of Neglected Tropical Diseases that are increasingly endemic in some APEC member economies, enhance regional cooperation on human security, and address emerging and re-emerging infectious disease outbreaks. The APEC-Life Sciences and Innovation Forum (LSIF) purposed a Blood Supply Chain 2020 Roadmap in 2015 to improve the safety and sustainability of blood supply in APEC economies through multi-disciplinary, coordinated and collaborative approaches. A Blood Supply Chain Partnership Training Network (PTN) was established to assist roadmap goals, with training on quality systems and leadership programs scheduled from 2016-2017, and further assessments until 2020. Risk communication and surveillance was emphasized in during the APEC Health Working Group (HWG) meeting in Lima, Peru on February 29th 2016, the Chair of the HWG, Dr. Victor Cuba, commented saying "Ebola, MERS and now the Zika virus underscore the increasing risk of health emergencies that we all face," and that "Adopting 'health in all policies' and a whole of government, society and region approach to health system development can help to make us safer and is at the core of APEC's health agenda."

Further approaches

 

Current research on vaccines for the Zika virus is prioritized on developing inactivated vaccines which are a safer option for pregnant women and those of childbearing age. The WHO has reported at least 15 ongoing projects to produce effective vaccines, though none have reached clinical trials. It is estimated that another two years will be required to develop a vaccine and five times longer for it become available to the general public and developing countries where treatment is most needed. WHO's Strategic Response Plan stresses further research beyond the purely health- related considerations, around economic and environmental considerations, including modeling of potential scenarios to estimate the impact of spread and economic costs.

(Penny Ou is the Research Intern of TIER and Student of George Mason University.)

 

Reference

1.      Zika Strategic Response Plan WHO http://apps.who.int/iris/bitstream/10665/246091/1/WHO-ZIKV-SRF-16.3-eng.pdf?ua=1&ua=1

2.      Situation Report Zika Virus Microcephaly GBS http://apps.who.int/iris/bitstream/10665/242439/1/zikasitrep-16Jun2016-eng.pdf?ua=1

3.      CDC Draft Inerim Response Plan http://www.cdc.gov/zika/pdfs/zika-draft-interim-conus-plan.pdf

4.      APEC Health Working Group Proposed Work Plan for 2016 http://mddb.apec.org/Documents/2016/SCE/SCE-COW/16_sce-cow_023.pdf

5.      LSIF Blood Supply Chain Partnership Training Network http://mddb.apec.org/Documents/2016/LSIF/LSIF1/16_lsif1_026.pdf

https://en.wikipedia.org/wiki/Zika_virus