Stopping Puerto Rico’s Zika crisis

As Congress debates a must-pass government funding measure this week, federal aid to combat the Zika virus has emerged as one of the most important provisions of the spending bill. After political feuding and partisan bickering, leaders in both parties appear to have reached a deal to break the months long Zika funding impasse.

This is encouraging news for the 3.4 million Americans living in Puerto Rico, who for too long, have been put at risk by the inability of Congress to act on this critical issue.

{mosads}Zika is causing a major crisis in Puerto Rico. The Centers for Disease Control and Prevention (CDC) projects that up to a quarter of the island’s 3.5 million inhabitants may become infected with Zika.

As a result, by this time next year, Puerto Rico is expected to have up to 270 babies born with microcephaly and an additional 7,800 newborns could suffer other brain defects not yet fully understood.

Zika’s effect on the brain’s neural stem cells is under investigation with one study showing that the virus reduced neural progenitor cells by a third, which suggests that Zika could cause brain defects even among children without microcephaly.

Lead exposure, which causes several neurological problems, also acts on neural stem cells and children infected with Zika may suffer similar effects. Studies in mice suggest that Zika may affect the adult brain too.

The medical cost of caring for a child born with microcephaly is conservatively estimated as $600,000 and rises to $4 million per child when factoring total costs including round-the-clock care and lost income of the parents.

That’s up to a billion dollars for bankrupt Puerto Rico’s struggling economy to care for the babies with microcephaly, which will recur each year until the epidemic ends.

With the effects on tourism, the economy has already seen a downturn and will continue to flounder as long as Zika persists — this will lead to ongoing drops in the tax revenues and public health funding needed to contain the epidemic.

Zika is just beginning to spread in Florida and is on pace to disseminate throughout the Southern US; the virus could end up affecting as many as 41 states. We need to act now to fight the epidemic in Puerto Rico and prevent it from becoming a similar crisis on the mainland.

When intelligence agencies attempt to prevent future attacks they look for patterns. In the case of infectious diseases the patterns are clear.

While we cannot always pinpoint the exact type of diseases that will affect us in the future or its method of distribution or dissemination we do know that their incidence level is increasing.

One does not need to go back to the horrors of the Spanish flu pandemic of 1918 in which up to 5 percent of the world’s population died. What these recent cases illustrate is that we — the national and international community working together — need should remember fundamental steps. These include research on the biology of the disease, short-term treatment options and research and development of safe and effective vaccines.

Additionally, the development of accurate and readily accessible diagnostic tools for early detection to reduce transmission and guide treatment is required.

In an era of rapid mobility of people and goods we simply need to create a permanent rapid response plan and team to guard against the next few epidemics and beyond because our national security depends on it.

Current Strategies Won’t Be Enough

Zika is transmitted by mosquitos and unprotected sex. As long as each infected person infects, on average, one or more people, the epidemic expands. Stopping Zika requires reducing this transmission rate below one. Most infected people have no symptoms at all or only nonspecific symptoms, such as fever and body aches, that are also seen with other, more common illnesses.

As a result, most infected people don’t go for testing and never know they are infected, even while passing infection onto others. Because of this ‘invisible’ transmission, we do not have an accurate idea of just how many people are infected.

Since an estimated 80 percent of the Zika infections are asymptomatic, over five times as many people are probably infected than the infections reported to public health authorities. Each additional of the Puerto Rico population infected represents 35,000 people who can infect others.

Current proposals for containing Zika concentrate on vaccines and eradicating mosquitoes. Research and development on vaccines is underway, but, assuming they are safe and effective, they are not expected to become available for use until 2018 or later, allowing too long a window of time during which Zika would likely become more entrenched.

Eradicating mosquitoes would require widespread spraying of insecticide across the island, an approach that is both costly and environmentally disruptive.

Below is a population density map of the island Puerto Rico, which is about 50 miles by 100 miles with an area of about 3500 square miles. The highest population density is in San Juan in the northeast, which is also where Zika infections are likely to accumulate. Zika, however, has already been reported across the island including in smaller cities.

For spraying to be effective, it would have to be applied intensively throughout the island, especially in the more populated half closer to San Juan. Such widespread spraying comes with grave environmental concerns and is opposed by some local groups.

There is already a tenor of distrust among communities and government, all of which would be exacerbated by aerial spraying. Even if applied in full, it is questionable whether spraying alone could eradicate enough mosquitoes within a reasonable time frame.

How to Stop Zika

Though the current situation in Puerto Rico appears daunting, we have faced much greater challenges in the past. Two of us advised the President of Guinea, one of the poorest countries in the world, on reining in its Ebola epidemic — all in the absence of a vaccine – by focusing on two principles.

First, we must identify a sufficient fraction of those who are infected, and providing them whatever resources are need to prevent them from infecting others. Secondly, we must encourage communities to adopt practices that sufficiently prevent further transmission

Both approaches helped ensure that each infected patient would infect, on average, less than one additional person, thereby causing the epidemic to burn out.

This requires widespread screening of all people with symptoms and otherwise in areas of known Zika transmission. Those infected with the virus can be engaged and supported to, by all means necessary, avoid mosquitoes and practice safe sex during the period of time during which they are infectious (current research suggests this to be two weeks for mosquito bites and possible longer for sex).

They can also be provided with bed nets, mosquito repellent, and other items to help protect themselves from mosquitoes.

Door-to-door testing is already being conducted in parts of Miami by local authorities, and it needs to be done throughout Puerto Rico and may also soon be needed elsewhere in the US mainland.

At the moment, the only limitation to this strategy is that Zika diagnosis can only be made by specialized labs with highly trained personnel that are not easy to scale.

We need a user-friendly screening test that public health authorities can use to voluntarily test people at their homes (if not a test that people can use themselves like urine pregnancy tests). People that screen positive with this test could then be confirmed by laboratory testing.

Building on the progress that diagnostic developers have already made, the development, validation, and approval of a user-friendly diagnostic needs to be sped up so that it can be put to widespread use within months by people worldwide to end the Zika pandemic.

Ranu S. Dhillon, MD, is an advisor to the president of Guinea and the country’s National Ebola Coordination Cell. Javier Ortiz is the executive director of the Puerto Rico Economic Recovery Initiative and is a partner at Falcon Cyber Investments. Devabhaktuni Srikrishna is the founder of Patient Knowhow, which curates patient educational content on YouTube. David Beier is a managing director of Bay City Capital and formerly served as chief domestic policy advisor to then-Vice President Al Gore. 

The views expressed by contributors are their own and not the views of The Hill.