Not only we have to deal with the bothering regular flies, now the screwworm has reached the United States! I know it sounds scary, but you don’t need to worry because the risk to you and your family is very low. However, it’s important to understand what’s happening and that’s what we are here for. If you are surrounded by animals or you just want to know how agriculture is protected, learning about the screwworm will help you see why experts take it so seriously. So, let’s get started!
What is a screwworm?
This is not a worm at all, it’s the larva of a fly called Cochliomyia hominivorax. The female fly lays her eggs in the wounds or skin of warm-blooded animals. When the eggs hatch, the larvae (baby flies) start to eat the flesh of the animal. They dig in a spiral, like the motion of a screw, which is where the name “screwworm” comes from.
This parasite can infect cattle, horses, wildlife, pets, and in rare cases, even humans. If not treated, this insect infestations can be fatal.
Why screwworms are a big threat
The screwworm parasite can devastate livestock. In cattle herds, a single outbreak can cause animals to die or require expensive treatment. Therefore, farmers may lose millions of dollars if their herds are infected.
A U.S. Agriculture Department report estimated that an outbreak in Texas could cost at least $1.8 billion in livestock deaths, medicines, and labor. Considering that Texas agriculture supports about 2 million jobs and is worth over $867 billion, the screwworm is a very serious threat.
The first U.S. case in a human
On August 4, the first human case of screwworm myiasis (a parasitic infestation of fly larvae) in the United States was confirmed. The patient was a Maryland resident who had recently traveled to El Salvador, where the parasite is more common. Thankfully, the person has fully recovered, and there is no sign that the screwworm spread to other people or animals in the U.S.
Officials stressed that the public health risk in the U.S. is very low, but the event is a reminder of how dangerous screwworms can be if they spread.
Past outbreaks and eradication
Screwworms are not new. They caused large outbreaks in Central America in the 1980s and 1990s. At that time, governments spent millions to wipe them out. For a while, they succeeded.
However, in the last two years, screwworms have returned in parts of Central America and are moving north toward Mexico. Today, the parasite is also found in Cuba, Haiti, the Dominican Republic, and some South American countries.
How the U.S. is fighting back
To stop the screwworm from spreading into the United States, the Department of Agriculture has announced a five-part plan. The main strategy is to release billions of sterile male flies into the environment. So, let’s see how this works:
- Sterile male flies are bred in large numbers.
- They are dropped by planes over southern Texas and Mexico.
- When these males mate with females, the eggs do not hatch.
- Over time, the population shrinks and eventually dies out.
This method was very useful back in the 1960s to stop the last screwworm outbreak in the U.S. However, today the problem is speed since the program was expected to start in 2–3 years, but many experts say it should begin sooner.
So, you shouldn’t be scared about the screwworm because the U.S. government has strong prevention plans, but you should stay informed. This is really important if you want to protect your animals, support agriculture, and feel confident that experts are on top of this threat.