Zika: The Importance of Listening to the Scientific Wake-up Call

See this op-ed published in these newspapers: The Brownsville Herald and The Monitor

 

We moved quickly to get mosquito nets. As I reached for insect repellents to include in packages for pregnant women, I remembered the look in the women’s eyes—panic. I felt their fear. The Zika virus had suddenly become personal.

 

It was January, 2016 in Puerto Rico when my training as a birth defects researcher and my passion for optimal preconception care crossed paths. My team was conducting an on-going study to examine the role of environmental factors in preterm births. As news of the Zika epidemic spread, our focus whiplashed into a new direction—how to arm the approximately 150 pregnant study participants with the best information to protect themselves and their families against Zika. It was a wake-up call, but an all-too familiar one.

You see, I worked at the Centers for Disease Control and Prevention (CDC) for 27 years, served as the Founding Director of the National Center on Birth Defects and Developmental Disabilities, and Assistant Surgeon General of the US Public Health Service. My research at CDC focused on finding causes of birth defects and ways to prevent them. 

Several prenatal infections have historically been linked to serious birth defects and adverse neurodevelopmental outcomes. Zika is the first infection transmitted by a mosquito bite to cause birth defects, but many other infections – cytomegalovirus, toxoplasma, herpes, for example – are known to injure babies during pregnancy. 

And then there’s German measles (rubella). It was the first viral infection shown to cause birth defects when the mother was infected during pregnancy. Rubella during pregnancy caused a set of devastating birth defects, including cataracts, deafness, congenital heart disease, called the congenital rubella syndrome. About 7% of babies with this syndrome also have autism, one of the few known causes of this condition. 

An epidemic of rubella in the United States in the early 1960s instilled a sense of urgency for vaccine development. Live, attenuated rubella vaccines were first licensed in 1969, followed by establishment of a national vaccination program in the United States that same year. The numbers of babies with the congenital rubella syndrome in the United States plummeted.

In 1999, I published a commentary outlining the feasibility of eradicating rubella. At the time, the World Health Organization (WHO) recommended that children receive the measles vaccine, even when the combination measles rubella (MR) vaccine became available, due to a cost difference of just 25 cents per dose.

In response, I successfully lobbied the March of Dimes to provide supplemental funding to countries that were not using the combination vaccine. I also encouraged Merck, the developer and manufacturer of the measles-mumps-rubella (MMR) vaccine, to focus their vaccine donation efforts on Honduras, a country with an excellent immunization program and strong surveillance. Data from Honduras showed MMR could markedly reduce congenital rubella as well as mumps. Today, it is the standard in all of the Americas, and rubella has been eliminated in the U.S. and in many other countries.

The discovery of congenital rubella syndrome was a wake-up call accentuating the need to monitor birth defects. Thankfully, the March of Dimes sponsored the development of a global network of monitoring systems known today as the International Clearinghouse of Birth Defects Surveillance and Research. This effort represents independent programs from around the world. However, the WHO lacks a unit or focus to specifically address birth defects, their monitoring, or their contributions to infant and neonatal mortality. This remains a major blind spot in global health. 

The cost of such a system cannot be a barrier—it is nothing compared to the cost of an epidemic like Zika. CDC estimated the care of a single child suffering the devastating effects of Zika to be somewhere around $10 million through adulthood. Currently, over 1,500 pregnant women have been reported to be infected with Zika in Puerto Rico alone and over 500 in the 50 states. These represent mostly symptomatic cases, since only about 1 in 5 infected persons have clinical symptoms. So in actuality, the number of infected pregnant women is likely much larger. Even if only 5 percent have a baby with serious birth defects, the lifetime cost would be staggering. 

Zika struck French Polynesia in 2013, but its role in brain disruption leading to microcephaly was not recognized until reports emerged from Brazil last year. This underscores the need to add birth defect monitoring to the tools of global public health practice. 

We need a warning system to identify when potential causes of birth defects emerge. It is the best way to develop countermeasures to prevent exposure to new recognized causes of birth defects. The solution often is not as simple as just avoiding those exposures—we must understand how they cause serious birth defects.

I was asked by the National Institutes of Health (NIH) to join an international consortium studying Zika infections in pregnancy. The consortium will enroll about 10,000 pregnant women from Brazil, Colombia, Central America and Puerto Rico.  It is a start that is turning a wake-up call into a call-to-action that includes more focused funding to understand the pathogenesis of major birth defects. 

But where will that funding come from? According to the Federation of American Societies for Experimental Biology, from 2003 to 2015, the inflation-adjusted budget for NIH fell by 22%. The success rate for grants at the National Institute of Child Health and Human Development is less than 12%. That means many researchers must delay or stop important research, and others are leaving the field altogether. 

Some of my Brazilian colleagues have described how inconsolable many Zika-affected infants can be. Will their cries be heard by Congress? Will our leaders support birth defects research and prevention strategies and finally establish a global birth defects surveillance program? The call must not fall on deaf ears any longer.

José F. Cordero, MD, MPH, is Patel Distinguished Professor of Public Health and head of the department of epidemiology and biostatistics at the University of Georgia. He is also a past-president of the Teratology Society.

 

 

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