More diseases, fewer barriers, more problems. Since 1980, the number and diversity of infectious disease outbreaks has increased significantly. There were fewer than 1,000 outbreaks of infectious disease from 1980 to 1985, according to a 2014 paper published in the Journal of the Royal Society. From 2005 to 2010, there were more than 3,000. Because this growth is linked to trends such as globalization, urbanization and climate change, scientists believe it’s likely that there will continue to be more outbreaks in the near future.

The good news, according to the authors of that 2014 paper, is that the number of infected people has gone down — thanks to coordinated efforts related to prevention, early detection, control and treatment. But all of that costs money. Lots of money. As the rate of outbreaks increases, then, it’s not surprising that the budgetary breather between infectious disease emergencies is getting shorter and shorter. Case in point: the overlap of Ebola and Zika. In December 2014, the United States mobilized against Ebola with a bill appropriating extra money for the 2015 budget, including $1.7 billion for the Centers for Disease Control and Prevention. But now, with Ebola in retreat in the West African nations most affected, the fear of an American outbreak is a distant public memory. Instead, it’s Zika that keeps us up at night, and the money is following that shift in attention. On April 6, the White House announced a plan to take $510 million of unspent Ebola money and earmark it for Zika-related activities.

Some Democrats think that’s still not enough money to combat Zika. A bill introduced by House Democrats on Monday called for $1.6 billion in additional 2016 spending for Zika-related activities. Although the bulk of the Ebola funds were designated for international assistance through the U.S. Agency for International Development, the biggest beneficiary of the Zika bill by far would be the CDC, which stands to gain $743 million in the bill’s current form.

FUNDING TARGET AMOUNT CDC $743m – Bilateral aid 325 – National Institutes of Health 277 – Public Health and Social Services Emergency Fund 233 – State Department 32 – Multilateral aid 14 – FDA 10 – USAID 10 – Where the proposed Zika funding would go Source: U.S. House of Representatives

The Zika funding, if approved, could be spent over multiple years, but it would still represent a huge increase in the CDC’s resources to fight vector-borne and emerging infectious diseases. From fiscal year 2013 to fiscal year 2016, the agency spent about $695 million on those issues. The House bill would be like getting four years’ worth of money all at once.

DISEASE FUNDING Zika (proposed) $743m – Influenza 188 – Emerging infectious diseases 147 – Immediate Zika response (existing) 50 – Vector-borne diseases 26 – Parasitic diseases (global health) 26 – How new Zika funding would compare to the current CDC budget Source: CDC

The bill’s impact on the National Institutes of Health would be much less overwhelming — which makes sense, as the NIH’s role is less about immediate, boots-on-the-ground outbreak response and more about funding research that will help us fight future outbreaks. The NIH doesn’t have a categorized budget the same way the CDC does. But it does offer an imperfect estimate of how the research it funds affects different health categories. The $277 million proposed for the NIH in this bill would be a drop in the bucket compared with the more than $2 billion directed to research on emerging infectious diseases and $459 million for vector-borne disease research this fiscal year.

DISEASE FUNDING Emerging infectious diseases $2,200m – Vector-borne diseases 459 – Influenza 285 – Zika (proposed) 277 – Malaria (and vaccine) 217 – West Nile virus 42 – How new Zika funding would compare to the current NIH budget Source: NIH

All of that, however, depends on the bill actually passing. And it probably won’t. Congress is leaving the bill to stew over a weeklong recess. Congressional Republicans are concerned that the Zika funding is a “blank check” for the federal government to spend on whatever it pleases. On Thursday, Senate Majority Whip John Cornyn told the Washington Post that these efforts amounted to a request for a blank check and that Democrats were set to play a shell game — taking funds for Zika but then using them for other projects.

This bill would certainly make that possible — at least to a point. All the bill’s funding requests include the provision that the money can be spent on “Zika virus, other vector-borne diseases, or other infectious diseases and related health outcomes, domestically and internationally.” Effectively, it would leave the door open to do exactly what the White House is doing with the Ebola money now: take funds earmarked for one emerging infectious disease and shift them to deal with another. As the rates of outbreaks go up, the desire for this kind of flexibility is likely going to increase, as well.