Since April, an outbreak of Ebola in the Democratic Republic of Congo has ballooned to 1,114 confirmed cases and 279 deaths, already the third-largest such epidemic since the disease was identified 50 years ago.

Despite its worrying size, this outbreak is threaded with mystery — particularly regarding its origins.

The cause is a little-known pathogen called Bundibugyo virus, one of three viral species known to cause Ebola disease. Scientists favor the idea that the virus normally dwells in animals, jumping the species barrier every now and then to cause an outbreak among people.

Continue reading “The Ebola Outbreak’s Central Mystery: Where Did This Virus Come From?” →

Linsey Marr, an environmental engineer, stood next to a pair of clear plastic boxes packed with tubes, nozzles and electronics, an odd-looking prototype that one day might serve to protect children in day care from airborne pathogens.

A nozzle filled the right-hand box with a faint silvery mist. A pump pulled some of that air into the left-hand box, where a sampler trapped floating particles and droplets. Soon, a digital screen bolted to the box turned red: “Detected! Dust mite allergen Der f 1.”

Continue reading “Buildings May Soon Have ‘Immune Systems’ That Fight Airborne Disease” →

In ancient Siberian graves, scientists have discovered the oldest traces of one of humanity’s greatest enemies. Examining skeletons of hunter-gatherers who lived 5,500 years ago, the researchers have isolated DNA from the bacteria that cause the plague.

The findings suggest that the plague, which would later devastate Europe in the “Black Death,” was already a lethal threat early in human history. That would be a big change from the earlier view of scientists: that these bacteria were originally relatively mild, and only later produced deadly outbreaks.

Continue reading “A Deadly Outbreak of Plague, Nearly 5,000 Years Before the Black Death” →