Tuberculosis outbreak

Science News, Jan 31, 1998 by Kathleen Fackelmann

M. tuberculosis continues to wage war, not just against the Yanomami, but against all peoples, notes biologist Christopher Wills of the University of California, San Diego. The recent emergence of drug-resistant strains of M. tuberculosis means that people who get the illness in the future may be harder to treat. Furthermore, as people continue to crowd into cities, M. tuberculosis may once again come to the fore.

Wills elaborated on the increasingly precarious relationship between M. tuberculosis and people in Yellow Fever, Black Goddess: The Coevolution of People and Plagues (1996, Reading, Mass.: Addison-Wesley).

"A lot of diseases that really do depend on people's proximity to one another might be in for quite a resurgence," says Wills.

RELATED ARTICLE: Egyptian Mummy Reveals Tuberculosis

Tuberculosis is a disease with a very long history, one that has been difficult to piece together with the standard tools of the pathologist.

In 1994, Arthur C. Aufderheide and his colleagues at the University of Minnesota in Duluth used a new molecular technique to identify traces of Mycobacterium tuberculosis DNA in a 1,000-year-old Peruvian mummy (SN: 8/30/97, p. 136).

Now, a German team has found molecular evidence of this microbe in a 3,000-year-old Egyptian mummy--the oldest such evidence of tuberculosis in any population, says Andreas G. Nerlich of Ludwig Maximilians, University in Munich. He and his colleagues describe the finding in the Nov. 8, 1997 Lancet.

The researchers discovered the linen-wrapped body in a tomb at Thebes-West, an ancient city on the Nile River. A pathological examination showed evidence of tuberculosis infection in the right lung, Nerlich says.

To confirm the diagnosis, the researchers removed samples of tissue from the lungs and extracted DNA from them. They searched for a particular stretch of DNA that is common to several microorganisms, including M. tuberculosis. Nerlich and his colleagues found the target DNA in tissue from the mummy's right lung. They then matched that stretch of DNA to one in M. tuberculosis.

To make sure the samples had not been contaminated with M. tuberculosis, the researchers also tested tissue from the mummy's unaffected left lung and lung tissue taken from modern people without the disease. They found no evidence of M. tuberculosis in those controls.

Nerlich and his colleagues plan to determine how widespread tuberculosis was in ancient Egypt. Their research already suggests that M. tuberculosis might have affected more Egyptians than previously believed--they have unpublished molecular evidence of M. tuberculosis in five additional mummies at the same burial site.