Saturday, April 8, 2017

The rat lung worm is a nematode parasite that has snails as an intermediate host and can infect humans as incidental hosts and cause a fatal brain disease


Climate denial by Trump and Scott Pruit, the head of the Environmental Protection Agency, is not only stupid, but could turn out to be very dangerous for human health.

Angiostrongylus cantonensis is a nematode that lives in the lungs of rats and has snails as intermediate hosts.  It is endemic in humans and can cause an often fatal brain disease that is untreatable. The rat disease was discovered in 1935 and is found world-wide, and the first human case of the disease was recorded in Taiwan in 1944.  Recently, human cases have been identified in Hawaii, California, Alabama, Louisiana, Florida, and along the Gulf Coast. “It is a worm infection introduced into North America through globalization,” said Peter Hotez, the dean of the National School of Tropical Medicine at Baylor College of Medicine. Transmission to humans occurs when people eat the intermediate hosts, which may even not be detectable on a leaf of lettuce that wasn’t washed. Even the slime left by an infected slug could transmit the disease and eating raw freshwater prawns, crabs, and frogs is also dangerous. In Maui there were six cases in a three month period.  The infected rats defecate worm larvae that are then eaten by snails, slugs and shrimp.  Humans are infected by eating contaminated food or even directly from handling infected snails. The parasites migrate to the brain meninges and can even penetrate into the brain. The disease is very difficult to diagnose.  Even though humans are not a true host, the presence of the worms causes a meningitis with severe headache, tremors, pain and inflammation caused by death of the worms and the host immune response. In fact, treatment with drugs used against other worm parasites can exacerbate the disease by killing the parasites and increasing inflammation.  

The rapid increase in the range of these parasites is almost certainly caused by climate change and globalization. There is an excellent recent paper entitled Geographic Range Expansion for Rat Lungworm in North America in Emerging Infectious Diseases (Volume 21, Number 7—July 2015) by Emily M. York, James P. Creecy, Wayne D. Lord, and William Caire.

Unfortunately, we are in the era of the fake-President Donald Trump, a climate denier, who is proposing a 30% decrease in the EPA budget. In fact, EPA workers are not allowed to even mention the term “climate change”. That reminds me of the king who once demanded that the ocean waves stop. I just hope that the FBI finishes its investigation and Trump and his crowd are indicted for treason and prosecuted. It should prove difficult for Trump to do more damage to our country when he is in jail.

But also unfortunately, this will certainly prove to be one of the least problems caused by climate change, and will pale in relation to the financial and ecological disasters caused by the rise in ocean level which will submerge major coastal cities worldwide, the expected mass migrations of people affected by the losses of water and food, and by the possibly nuclear wars caused by these migrations. In fact I doubt that our civilization will survive this tremendous damage to its infrastructure. 

Ah well, I have no children to suffer, but I am sure that the politicians such as Trump and the Republicans have children and grandchildren who will wonder why their ancestors let this happen to our world!

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