On Pandemics by David Waltner-Toews

Author:David Waltner-Toews
Language: eng
Format: epub
Publisher: Greystone Books
Published: 2020-06-15T00:00:00+00:00

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RATS, BATS, AND MONKEYS: LASSA, EBOLA, AND MARBURG

HEMORRHAGIC FEVERS: the name says it all, and it conjures up many of our darkest fears. These diseases all, it seems, come out of the rain forests of Africa. They are described as “terrorizing” or “stalking” the human race. The agents are always “deadly,” and they are “killers.” They are reason enough for firebombing African villages and threatening to do the same to American cities, as in the movie Outbreak. They have names such as Lassa, Ebola, and Marburg. Marburg? Germany? Yes, and the strange thing is that if you are a virologist, used to looking at electron micrographs, you would say that Lassa was the one that doesn’t belong. It’s an arenavirus, you would say. The others are filoviruses; they look kind of stringy.

For non-virologists, what is more important is this: they all, more or less, start with malaise and aching muscles and then move on to high fever, coughing, diarrhea, pain everywhere, and, in the worst cases, bleeding all over, brain problems, shock, and death.

In 1969, a nurse in Lassa, North-Eastern State, Nigeria, came down with fever, aches, and pains—the unremarkable symptoms of serious tropical diseases such as malaria, or diseases of poverty such as typhoid fever. When she didn’t get better after being treated locally, she was flown to a hospital in the Nigerian city of Jos. She died. One of the nurses who had taken care of her there also died. A third nurse, who had helped with the post-mortem of the first, became ill and was flown home to the United States in a commercial airliner. The Yale Arbovirus Research Unit isolated a virus from her blood and called it Lassa virus. A laboratory worker at the Yale laboratory fell ill, was treated with a transfusion of serum from the nurse, who was recovering and presumably had antibodies. The lab worker recovered. Five months later, another laboratory technician at the lab died of Lassa fever. No one knows how it happened.

The natural home of the Lassa fever virus is an African soft-furred rat, also called a multimammate rodent, Mastomys natalensis. Mastomys are at home in savanna woodlands common throughout parts of sub-Saharan western Africa. The rodents are sometimes described as pests and sometimes as food. I guess that depends on where they are found and how hungry you are.

Lassa fever virus belongs to a larger family of rodent-loving viruses. Members of this family include Machupo virus (causing Bolivian hemorrhagic fever), Junin virus (Argentinian hemorrhagic fever), Guanarito virus (Venezuelan hemorrhagic fever), and lymphocytic choriomeningitis virus (found in Europe and North America and causing “flu-like” lymphocytic choriomeningitis disease, or LCM, and only rarely meningitis in people).

In the early 1970s, Lassa was considered a rare disease, which killed about half the people it infected, mostly in hospitals. But then, many diseases are considered serious when first discovered, simply because the most serious cases are the ones first reported. For a few years, small outbreaks with high death rates were reported from hospitals in Nigeria and Liberia.

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