The Zika Virus Epidemic: Challenges and the Road Ahead

August 5, 2016

On February 1, 2016, the World Health Organization declared the Zika virus “a public health emergency of international concern.” Since early 2015, when it was first declared an epidemic in Brazil, 60 countries and territories have been affected by the virus. WHO and CDC have concluded that scientific evidence supports the link between Zika virus infection and microcephaly. In response to the urgency of this global health concern, IANPHI’s President Mauricio Hernández-Avila, in conjunction with the Oswaldo Cruz Foundation (FIOCRUZ) and with the support of the Inter American Developing Bank, requested members to participate in a conference to discuss surveillance strategies, preparedness, and response to the current population living in the critical situation.

Held in Rio de Janeiro, participants of the three-day summit included leadership of 15 Latin American national public health institutes (NPHIs), and experts from PAHO, the Public Health Agency of France, the U.S. Centers for Disease Control and Prevention, the Public Health Agency of Canada, Public Health England, the Secretary for Access to Rights and Equity at the Organization of Americas State, and other international organizations. The focus of the meeting was to analyze public health priorities and develop a research agenda for the Zika epidemic for the Americas region.

On the first day of the meeting, experts summarized the impact of the Zika virus epidemic in the Americas, lessons learned, and balance of social and economic effects in the region. PAHO representatives presented the main actions taken to support detection, prevention, and control of the virus, as well as the initiative of mapping all regional research projects. A summary of the strategies to analyze, manage and communicate risk were presented by the Epidemiological Surveillance experts from Ministry of Health of Brazil and Colombia. NPHI leadership from Peru and México presented integrated entomology and epidemiological surveillance systems including use of the geospatial platform for early detection of risk dissemination of diseases associated to Aedes vector. Phylogenetic studies were also presented in order to compare outbreaks in different parts of the world.

In regards to clinical and laboratory diagnosis, experts from the Arboviral Diseases Branch of the CDC discussed the process of development, validation, and harmonization of algorithms and techniques for Zika laboratory diagnosis. The use of real-time PCR in the first week of diseases was proven to be the most reliable test to confirm acute cases and the complicated situation of cross-reactivity using IgM and IgG as well as PRNT detection to further define previous exposition to the virus. The availability of the virus to be detected in urine in acute infection in the first two weeks was mentioned.

The first day concluded with a panel focused on surveillance models, supporting a more proactive, qualitative and territorial approach, rather than the classical reactive quantitative approach of counting suspected and laboratory confirmed cases. Emphasis was placed on the importance of geographic distribution of the vector and the disease, rather than counting cases. The social determination of the vector and disease distribution was considered of highest concern, including the need for more multilateral financing of research instead of bilateral projects. Of equal concern is the need to prioritize medium and long-term actions because the impact affects both the child and the mother. PAHO representatives emphasized the importance of laboratory networks for the purpose of sample and data sharing.

The second day of the meeting, the discussion continued linking the Zika virus infection with microcephaly and Guillain-Barre syndrome, and studies from sequential arbovirus infection and co-infection. A representative of FIOCRUZ Brazil concluded there is strong evidence of causal association; however, there is a need to establish and measure its effect, to investigate associated mechanisms, possible interventions. The Public Health Agency of France attributed the effects of microcephaly and other adverse pregnancy outcomes to the Zika virus in the frame of medical investigation or surveillance data. In particular, some challenges are the actual feasibility of pregnant women, in all French territories and the Americas, to have access to prenatal care.

In regards to data on GBS from Colombia and the regional unit of the French Public Health Institute located in the French Caribbean and Guiana, an increase in the number of cases that resulted morbidity following the Zika virus infection was revealed. This trend further indicates a need to standardize protocols to support this causality.

The Public Health Agency of Canada described the importance of risk communication to help decision-makers, stakeholders, and the public make well-informed choices to protect against and minimize risk. Governments face challenges during a public health crisis such as inconsistent communication among involved organization, failing to reach at-risk populations with appropriate information, failing to acknowledge risk perception and putting health information for the public upfront, before government action. Best practices for risk communication are based on transparency, coordinated messaging, working with stakeholders and making information easy to find and understand. A call-to-action must be a clear, culturally and emotionally sensitive message that addresses the wants and needs of the public, and is adaptable.

The National Institute of Public Health of Chile discussed the current available guidelines for caring for pregnant women during a Zika virus outbreak. Increased awareness of national contraceptive programs, in addition to counseling, are strategic ways to provide women with the tools needed to make a safe choice regarding pregnancy during this epidemic.

The last day of the meeting focused on vector control strategies. The Technical Advisory Group of Public Health Entomology of PAHO recommended that vector control and the response strategy to the Zika Virus epidemic are matters of international importance. The representative of National Institute of Public Health of Mexico presented the main gaps in the vector control programs, including the lack of trained personnel and the limitations of tracking systems that are focused on human clinical cases and are not integrated to include entomology monitoring.

The sustainability of disease control programs requires a sense of community ownership, including the use of community resources, ideas, and leadership in providing program design and direction. IANPHI links and strengthens the government agencies responsible for public health. Without these international connections, epidemics, such as Zika, are much more likely to be uncontrolled and unmonitored. The peer-to-peer model provides additional support, resources and expertise to help grow national public health institutes as well as respond decisively and effectively to public health threats.

Since the meeting between international health officials in Brazil in February, officials in Colombia have reported an end to the Zika virus according to the New York Times. Fernando Ruiz Gómez, the deputy health minister, has said he expected an influx in cases of microcephaly in September and October as women that are infected begin to give birth. However, cases of the virus peaked in March and have consistently dropped in the following months. This is the first time a South American country has been able to reverse the trends of the disease.

Despite the fact that Brazil has been the country hardest hit by the Zika virus, the risks of infection for 2016 Olympic participants and attendees are substantially lower than residents of Brazil. Because of the modern amenities, time spent indoors, and precautionary measures, foreigners are less likely to transmit the virus according to the Annals of Internal Medicine published by The American College of Physicians. Even if a visitor were to be infected with Zika, an infection typically clears the human body within 10 days, meaning that people who are infected probably won't be contagious by the time they head home. Regardless, notable athletes have back out of the Rio 2016 Olympics due to the risk of transmitting the virus. 

The outcome of the meeting can be summarized by the following:

  • Develop of methods and enhancement of surveillance approaches, include a standardization of indicators.
  • Organize a workshop bringing together health surveillance experts from across the Institutes and identify the most appropriate model and subsequent training needs.
  • Develop an algorithm to combine clinical, laboratory and epidemiological data
  • Identify collaborations and training programmed to aid improvements in surveillance capabilities– overlapping areas should be considered for maximum benefit.
  • Focus on capacity building to enable compliance with International Health Regulations and development of good laboratory resources for detection of outbreaks and emerging pathogens.
  • Develop a corpus of Good Practices to include social considerations, public health needs
  • Promote the concept of health security, with the recognition of economic impact, with Local Governments to develop a process for unhindered access to funding for emergency management.
  • Build laboratory facilities capable of diagnosis of novel pathogens, perhaps through a network of regional laboratories.
  • Integrate vector control programs.