THIS IS EITHER JUST GOOD LUCK, OR IT’S MORE SUBSTANTIVE GOOD NEWS: Dallas Ebola Conundrum: Duncan Family Members and Emergency Room Staff Not Ill.

The onset of Duncan’s symptoms was September 24, which means that it has been 22 days since the folks in the apartment and the emergency room personnel could have been first exposed to the virus. The people from the apartment are currently quarantined and, if they show no symptoms, are expected to be released on Sunday, October 19.

Is there a signficant difference in the infectivity of early stage Ebola patients compared to later stages when symptoms are more severe? If so, this could bode well for the folks whose contacts with Duncan and the ill nurses were early and fleeting. Here’s hoping.

Indeed. And what about Duncan’s ambulance crew? Plus, from the comments: “I hate to say it, but things like this make me wish we had a, wait for it, government agency that could really land on infectious disease outbreaks with expertise and authority. Perhaps a Disease Control Center, something like that?” Yeah, like in the movies.

Plus, it appears that we may need to wait longer, according to WHO: “The period of 42 days, with active case-finding in place, is twice the maximum incubation period for Ebola virus disease and is considered by WHO as sufficient to generate confidence in a declaration that an Ebola outbreak has ended. Recent studies conducted in West Africa have demonstrated that 95% of confirmed cases have an incubation period in the range of 1 to 21 days; 98% have an incubation period that falls within the 1 to 42 day interval.” Of course that means 2% take longer than 42 days. That’s not a lot, but at 1 in 50 it’s not a little, either.

UPDATE: Tom Frieden Admits Officials Don’t Know How Ebola Transmission Occurred. “Centers for Disease Control and Prevention Director Tom Frieden admitted to a House panel on Thursday that officials still don’t know exactly how two nurses contracted Ebola from Thomas Eric Duncan, the first man to be diagnosed with the virus in the U.S.”

ANOTHER UPDATE: Yale student at Connecticut hospital being tested for Ebola. “The patient is one of two Yale University graduate epidemiology students who traveled to Liberia last month to advise the health ministry on using computers to track Ebola, according to Laurence Grotheer, a spokesman for New Haven Mayor Toni Harp. . . . Yale University said the students had not traveled into areas in Liberia where Ebola was present.”

YET ANOTHER UPDATE: Yale-New Haven Patient Tests Negative For Ebola.