When tuberculosis kills lung tissue, it can produce gaping
holes like in the lung on the right.
For a long time, tuberculosis was a gruesome and incurable disease. Antibiotics changed that, but over the last century, as the drugs have been incorrectly used, the tuberculosis bacterium has been developing resistance to them. Multi-drug resistant tuberculosis, which requires a cocktail of many drugs to treat it, has become common. Now Indian doctors have reported in a medical journal that a strain that is resistant to all known drugs for tuberculosis has appeared in Mumbai. Twelve patients so far have been diagnosed with the strain, and it’s likely that they are just the tip of the iceberg in terms of those infected.
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Around two million people die each year from TB, and the bacterial infection is startlingly widespread—the World Health Organization says about one in three people around the world carry Mycobacterium tuberculosis (and humans may have been carrying it around for at least 9,000 years). Thankfully, TB is latent in the vast majority of these cases. But tuberculosis’ pervasiveness presents the question of just how the bacteria evades our immune system to set up shop on a long-term basis.
According to a study led by Gobardhan Das in the Proceedings of the National Academy of Sciences, stem cells might be the answer. Particularly, mesenchymal stem cells (MSC).
TB recruits mesenchymal stem cells to the lungs, where they help suppress the immune system that fights disease… The stem cells produce nitric oxide, a chemical that reduces the type of white blood cells called T-cells, the researchers wrote. [Bloomberg]
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The first scientific autopsy on an ancient Egyptian mummy, performed back in 1825, might have botched the cause of death. The original ruling was that the mummified woman, Irtyersenu, died of ovarian cancer, but a new study strongly suggests she died of tuberculosis [BBC News]. The original autopsy was performed by one Dr. Augustus Bozzi Granville, a surgeon and a gynecologist (and apparently a fan of infectious diseases; he personally overcame bouts with malaria, bubonic plague and yellow fever).
Irtyersenu is a remarkable specimen in that she was mummified with her organs intact. Most mummies have their organs removed or dissolved inside their bodies prior to mummification. Dr. Granville was correct in detecting that the mummified woman had an ovarian tumor—but later studies determined it was benign. Granville studied her pelvic bone and also determined the woman to be an overweight mother between the ages of 50-55 when she died.
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Developing nations may be where infectious diseases like malaria and tuberculosis flourish, but ironically, these regions often have the fewest resources for equipment to diagnose the maladies.
A new fluorescence microscope, however, could offer an affordable solution: One that attaches to an ordinary mobile phone. Once snapped on to any mobile phone that has a basic camera function, the microscope can illuminate pathogens, allowing the viewer to identify them and even send the image to a health care facility, according to an article published in the journal PLoS ONE.
To use the device, called the CellScope, fluorescent molecular “tags” are added to a blood sample, which attach themselves to a certain pathogen, such as tuberclosis-causing bacteria. The pathogens are then illuminated by microscope, which uses cheap commercial light-emitting diodes as the light source – in place of the high-power, gas-filled lamps used in laboratory versions of the device, and cheap optical filters to isolate the light coming from the fluorescent tags [BBC News]. The apparatus allows the viewer to “see” things as small as one-millionth of a meter.
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A genetic analysis of two 9,000-year-old human skeletons found off the coast of Israel reveal that the Neolithic people were infected with tuberculosis, making them the earliest known TB cases to be confirmed with genetic testing. The bone discovery contradicts the long-held theory that human TB evolved from cattle strains around the time of animal domestication, says [study coauthor] Helen Donoghue…. Rather, high population densities could have made it easier for the disease to spread [New Scientist].
The skeletons of a mother and child were found amidst other artifacts of a Neolithic village, called Atlit-Yam, which is now covered by the Mediterranean Sea. A roughly 25-year–old mother had apparently passed on the bacterial infection to her 1-year–old child, after which they both died and were buried together…. Salt water, sand and clay had covered the bodies, providing excellent conditions for bone preservation. Atlit-Yam was located within a coastal marshland before its immersion by the rising ocean [Science News].
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A new study has found that countries in Eastern Europe and the former Soviet Union that accepted International Monetary Fund loans in the 1990s had an immediate increase in tuberculosis cases, and more people died from the disease. The study’s authors argue that the strict conditions of the loans, which often call for “austerity measures,” may have caused governments to slash health services, thus bringing about the surge in TB cases.
The fund strongly disputes the finding, saying the former communist countries would be much worse off without the loans. “Tuberculosis is a disease that takes time to develop,” said William Murray, a spokesman for the fund, “so presumably the increase in mortality rates must be linked to something that happened earlier than I.M.F. funding. This is just phony science” [The New York Times].
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