YEARS OF DIVESTMENT ERODE WEST NILE VIRUS INFRASTRUCTURE

FEATURING: Dr. Don Reed, Dallas, Texas

 

YOUR BRAIN ON A SKILLET

Dr. Don Read, a decorated Vietnam veteran and prominent colorectal surgeon in Dallas, was walking with his wife one summer evening. Within days, he was experiencing severe, flu-like symptoms. Soon, he was sleeping more than 20 hours a day. By week’s end, Don says, “both of my legs were paralyzed, both of my arms were almost paralyzed. I was sleeping 23 and half hours a day. I couldn’t talk. I couldn’t hear. I couldn’t write. All from a mosquito bite.”i

A mosquito had infected Don with the West Nile Vile virus (WNV). Symptoms typically include fever, headache, and fatigue, if they present at all. But Don’s case wasn’t typical. He was one of the less than one percent in whom the virus attacks the central nervous system. “Like putting your brain on a skillet, and frying it,” he said.

For the rest of his life, Don will wear braces on both of his legs because of his “polio-like paralysis.” Still Don is grateful to be alive. He runs a support group for WNV survivors and educates the public about the disease, and how to prevent it.

DEAD CROWS AND MOSQUITOS

WNV first appeared in the Western Hemisphere in the summer 1999, and New York City was ground zero. The rare virus infected crows and other birds, hundreds of which “fell dead from the sky.” Mosquitos fed upon infected birds’ blood, and passed the virus on to humans.ii Today, WNV is the most common mosquito-borne disease in America. An estimated 3 million Americans have been infected, with more than 16,000 neuroinvasive cases similar to Don’s, and almost 1,600 deaths in the United States.iii

The federal Centers for Disease Control and Prevention (CDC) works in concert with state and local health departments 24/7 to prevent, detect, and control the growing risk of infectious disease outbreaks. Epidemiologists or “disease detectives” at the CDC and embedded in states and communities work on the front lines, investigating outbreaks like WNV and figuring out how to stop them.iv As Dr. Alexandra Levitt writes in her new book, Deadly Outbreaks:

Their work typically occurs behind the scenes, unknown to the general public…As a result, the importance of what they do may be overlooked, and their jobs may be endangered by budget cuts, especially at times of recession and belt-tightening.v

Personal responsibility goes a long way in preventing WNV infection—covering your skin, avoiding outdoor activity at dawn and dusk, and wearing insect repellent. But there’s only so much any one individual can do. It falls to the government to monitor the disease and coordinate the response. As such, epidemiologists and laboratory scientists at the federal, state, and local level play an indispensible role in our health and security.

WEST NILE FORGOTTEN, BUT NOT GONE

As WNV spread rapidly across the county, Congress provided essential funding for health departments to build capacity to monitor and prevent it through CDC’s Epidemiology and Laboratory Capacity (ELC) grant program. At its peak in 2002, federal ELC grant funding for WNV was $35 million; starting in 2006, it precipitously declined. During 2009-2011, fewer than 1,000 annual WNV cases were reported in the United States. “As the incidence declined, so too did concern about WNV among the media, the general public, the research community, and policymakers,” said Dr. Stephen M. Ostroff.vi By 2013, federal funding for WNV was only $9.4 million.

Findings from a Council of State and Territorial Epidemiologists (CSTE) assessment of state and select local health departments on vector borne disease surveillance capacity in 2012 show that the epidemiology, laboratory, and mosquito monitoring capacity built at the state and local levels for WNV with ELC funding has eroded since last assessed in 2004.vii

According to Dr. Ostroff, “such complacency had serious ramifications when a nationwide resurgence of [WNV occurred in 2012.” Don’s hometown of Dallas, Texas was one of the most severely affected, with 173 cases of West Nile neuroinvasive disease, 225 cases of West Nile Fever, and 19 deaths.viii

Studies show that in Dallas, the rapid increase in human cases tracked closely with growth in the number of mosquitos, fueled by warmer winters and more precipitation. But the eroding public health infrastructure may have also played a role, as in the absence of government funding, some programs have been eliminated and others scaled back.ix Indeed austerity in the end costs more:

The cost of surveillance and preventive efforts are likely to be less than the costs associated with responding to major [WNV] outbreaks, as evidenced by the $8 million in estimated [WNV]-related health care costs and $1.6 million for aerial spraying [in Dallas] combined with the significant burden of illness, disability, and death.x

As Dr. Donald R. Hopkins of The Carter Center notes, “the struggle between humans, microbes…is long and ever-changing, but never ending.”xi The data show that WNV—as are other infectious diseases—is predictable in its unpredictability. The current fiscal environment undermines the public health infrastructure, and the scientists who are trying to keep up.

Findings from a Council of State and Territorial Epidemiologists (CSTE) assessment of state and select local health departments on vector borne disease surveillance capacity in 2012 show that the epidemiology, laboratory, and mosquito monitoring capacity built at the state and local levels for West Nile Virus (WNV) with Epidemiology and Laboratory Capacity (ELC) grant funding from the Centers for Disease Control and Prevention (CDC) has eroded since last assessed in 2004.xii

Specifically:
  • The majority of these health departments indicate they lack sufficient epidemiology, laboratory and mosquito surveillance personnel to rapidly detect and respond to a new mosquito-borne disease threat.
  • Once conducted by all mainland states, less than half now monitor bird mortality—important since birds are often the first sign of WNV—and fewer states conduct mosquito surveillance, compared to 2004.xiii
  • Those that do, set fewer traps and do not test as many mosquito pools compared to years past.xiv

With states having cut back on mosquito surveillance, active surveillance for human disease and laboratory testing for WNV and other vector-borne viruses, ArboNET—a national surveillance system managed by CDC and state health departments that maintains data on human and veterinary disease—has also been compromised. This comes at a time when the need for a robust system is high:

  • 2012 was one of the most intense WNV seasons since 1999, with 2,873 cases of neuroinvasive disease and 286 deaths reported (see graph).
  • The threat of dengue outbreaks is growing with an average of 492 imported cases detected in more than 30 states annually 2010- 2012.xv In 2013, local dengue transmission was documented in Florida, Texas and New York State.xvi
  • Chikungunya virus transmission was documented in the Americas for the first time.xvii

AUTHOR
Council of State and Territorial Epidemiologists

SOURCES
i Interview with Dr. Don Read and Dallas County Medical Society. Available a thttp://www.dallas-cms.org/emerg_response.cfm

ii Levitt, A.M., Deadly Outbreaks: How Medical Detectives Save Lives Threatened by Killer Pandemics, Exotic Viruses, and Drug-Resistant Parasites. Deadly Outbreaks: How Medical Detectives Save Lives Threatened by Killer Pandemics, Exotic Viruses, and Drug-Resistant Parasites. Skyhorse Publishing. 2013.

iii Ostroff, S.M., “West Nile Virus: Too Important to Forget,” JAMA. Vol. 310, No. 3. July 17, 2013.

iv Levitt, A.M., Deadly Outbreaks. 2013.

v Ibid.

vi Ostroff, S.M. JAMA. July 17, 2013.

vii The Council of State and Territorial Epidemiologists. Assessment of Capacity in 2012 for the Surveillance, Prevention and Control of West Nile Virus and Other Mosquito-borne Virus Infections in State and Large City/County Health Departments and How it Compares to 2004. Available at http://www.cste2.org/docs/VBR.pdf. Accessed March 10, 2014.

viii Ostroff, S.M. JAMA. July 17, 2013.

ix Ibid.

x Chung, W.M, et al. “The 2012 West Nile Encephalitis Epidemic in Dallas, Texas.” JAMA. 2013; 310(3): 297-307.

xi Levitt, A.M., Deadly Outbreaks. 2013

xii The Council of State and Territorial Epidemiologists. Assessment of Capacity in 2012 for the Surveillance, Prevention and Control of West Nile Virus and Other Mosquito-borne Virus Infections in State and Large City/County Health Departments and How it Compares to 2004. Available at http://www.cste2.org/docs/VBR.pdf. Accessed March 10, 2014.

xiii Idid

xiv Idid.

xv USGS. Dengue fever (imported, locally acquired) – Human. Available at: http://diseasemaps.usgs.gov/index.html. Accessed December 20, 2013.

xvi Idid.

xvii World Health Organization, Global Alert and Response. Chikungunya in the French part of the Caribbean isle of Saint Martin. December 10, 2013. Available at http://www.who.int/csr/don/20131210a/en/index.html. Accessed December 20, 2013.