As I mentioned last week, the idea of zombies comes from a magical tradition in the varieties of Voudo or Voudon practiced in parts of Africa, Haiti, and the US. A bokor, or sorcerer, casts a spell on a living person to make them undead, or casts a spell on a corpse to revive them. Traditionally, and as presented in early zombie entertainment like The Magic Island, zombies were revived to be used for manual labor, including murder.
Scientists like to explain the concept of zombies with diseases. Africa is home to several terrifying diseases that have zombie-like symptoms, so it is no wonder that we get the idea from African traditions.
A classic zombie-making disease, this time native to sub-Saharan Africa, is Sleeping Sickness, which most scientists and medical professionals now refer to as African trypanosomiasis. The parasitic disease, caused by protozoa, starts with the haemolymphic stage, in which the victim suffers fever, headaches, itching, and joint pain. Fevers can last up to a week, but are separated by intervals, so the initial symptoms are very similar to another, more treatable chronic illness – malaria. However, as the disease progresses, the victim’s lymph nodes swell up, often to tremendous sizes. If the disease remains untreated – and there are very few effective treatments for human trypanosomiasis – the victim begins to suffer anemia and dysfunctions of the kidneys, heart, and endocrine system.
That’s only the first stage. As African trypanosomiasis progresses into the neurologic, or second, stage, the parasite invades the nervous system and passes the blood-brain barrier. The victim loses the ability to concentrate, or perform simple tasks such as holding a pencil, or walking. Sufferers often develop tremors and a shuffling gait as they lose muscle strength. Their circadian rhythm flips – instead of sleeping at night, victims find it impossible to stay awake during the day, and cannot sleep at all at night.
After moving through the second stage, the unfortunate victim will eventually pass into a coma, suffer organ failure, and die.
“This is an infection that carries nightmarish qualities, reducing many of its victims to a zombie-like state before they go into a coma and die,” said Professor Sanjeev Krishna of the University of London, who is a doctor at a hospital in Lucala, Angola, said in a BBC interview. “Those that do survive can be left with irreparable brain damage.”
In Uganda, one in every three people are at risk of catching human trypanosomiasis, and the disease kills 50,000 to 70,000 people annually. The disease is transmitted by the tsetse fly, an insect that feeds on blood from both humans and animals. There is still no vaccine to prevent infection, and metarsoprol, one of the few “effective” treatments against the disease, contains enough arsenic to kill 1 in 20 people treated with it. If caught in the early stages, fortunately, the disease is treatable, but the most effective methods for prevention are to kill any cattle with the disease – putting entire towns at risk of starvation – or destroying all tsetse flies in the area.
So far, there have been no reports of sleeping sickness outside of Africa, because the disease relies on the tsetse fly for transmission, although, frighteningly, there has been one case of the disease being transmitted sexually. Despite that, because there are no tsetse flies outside of Africa, those of us who do not travel to Africa very often are safe from trypanosomiasis, right?
Nope.
There is already an American form of trypanosomiasis, spread throughout South and Central America, caused by a protozoan, with similar symptoms to African trypanosomiasis – the main difference is, in American trypanosomiasis, there is no change in circadian rhythm. That form of the disease, normally called Chagas Disease, is spread through a triatomine bug, also known as a kissing bug because they drop down onto sleeping victims’ faces at night and suck their blood. While they are not related to bed bugs (Cimex lectularius) they have similar nighttime feeding habits, so African trypanosomiasis has a ready host in the Americas, with bed bugs a potential next jump. Have I mentioned that bed bugs have made a huge come-back in the last 10 years? The top 10 most infested cities in the United States, at the moment, are Cincinnati, Ohio; Columbus, Ohio; Chicago, Illinois; Denver, Colorado; Detroit, Michigan; New York, New York; Philadelphia, Pennsylvania; Dayton, Ohio; and Baltimore, Maryland.
So. Completely. Screwed.
