The following was written by Meredith Li-Vollmerfor Public Health Insider:

With Zika virus dominating headlines, the Big Cities Health Coalition reached out to Dr. Jeff Duchin, Health Officer at Public Health – Seattle & King County, to discuss some of the unique challenges in the U.S. arising from the sudden emergence of this virus. We’ve excerpted it here (read the full interview on their Frontlines blog):

It seems like every year or so, there’s a new global infectious disease outbreak, like Ebola or MERS, and now Zika. Why is this, and what should we be prepared to do about it?

Part of this is due to the increased encroachment of humans on new habitats coupled with increased ease of regional and global travel, creating more opportunities for disease to spread. Humans and disease-carrying organisms are coming into more contact through urbanization and deforestation. Climate change has facilitated the movement of vectors like mosquitoes to broader habitats. And microorganisms have been adapting to be resistant to some of the treatments that have worked in the past.

To be effective in our response to infectious diseases, we must invest in a stronger public health system at the federal, state and local levels. State and local public health departments are on the front lines in our communities. We do surveillance to track and monitor diseases, update and coordinate our partners in hospitals and healthcare, provide public information and education, and operationalize federal guidance and plans on the local level.

Ongoing cuts in federal funding for the CDC and state and local public health  have reduced our ability to respond. Across the nation, the cuts at state and local health departments have compromised critical health emergency preparedness capacity and shrunk the public health workforce.

We appreciate the strong support the Big Cities Health Coalition and NACCHO have shown for the White House’s emergency funding for Zika virus readiness and response capacity. Without this funding, the federal public health system would be seriously hampered in developing the diagnostic tests and vaccine needed for Zika virus and in researching the link between Zika virus infections, birth defects, and other health risks. At the state and local levels, this investment will shore up mosquito control programs and develop the infrastructure needed for testing and surveillance of the disease.

Yet, while intermittent supplemental funding during health emergencies is critical, it does not provide the stability needed to ensure that an adequate level of public health resources, personnel and systems are available to address the many infectious, non-infectious and chronic disease health challenges facing our communities every day. And when emergency funds displace resources for other public health work, the net benefit is diminished. Because Zika is assuredly the latest, but not the last global infectious disease threat to emerge, long-term solutions to the lack of stable public health funding can’t come too soon.

Just how much of a threat is Zika virus to the American public?

In the US, the risk is mainly to travelers. Zika is a primarily a concern for pregnant women that are in or have traveled to areas with Zika virus transmission. Current information about Zika infections in pregnant women suggests a link to a serious problem in newborns called microcephaly, an abnormally small brain and skull, and other poor pregnancy outcomes. Zika can also spread through sex with a man who has been in a Zika-affected area because the virus can survive in semen for an extended period.  A link between Zika and a type of paralysis that can last weeks to months called Guillain Barré syndrome is also being investigated.

Based on experience with dengue and chikungunya (viruses that are transmitted by the same Aedes mosquitoes) Zika is unlikely to cause large outbreaks in the US. In areas within the US where these mosquitos exist, limited transmission of Zika could occur. For those who are infected, only about one in five will experience symptoms, and symptoms are typically mild: fever, rash, joint pain, or conjunctivitis (red eyes).

In the coming months, there are large-scale events happening in countries with ongoing Zika transmission, like Carnival in much of Latin America and the Caribbean, and the Olympics in Brazil. What are some of the challenges presented by these events?

International travelers can unknowingly carry infectious diseases to their travel destinations.  Whether the disease then spreads or takes hold locally depends on a variety of factors. Density of population is one factor that facilitates spread of infection, while pre-existing population immunity would prevent it. For diseases like Zika, dengue, and chikungunya, the specific mosquitoes that can carry the virus must be present for transmission to occur.  Factors that reduce opportunities for mosquitos to bite an infected person and then bite a susceptible person would reduce the risk of spread.  The more that susceptible people are crowded together, the more opportunity a disease would have theoretically to move from person to person.