How Scared Should We Be?

Ebola Virus

David Willman relays concerns from some Ebola experts about our knowledge of how the disease spreads, some of whom “question the official assertion that Ebola cannot be transmitted through the air”:

In late 1989, virus researcher Charles L. Bailey supervised the government’s response to an outbreak of Ebola among several dozen rhesus monkeys housed for research in Reston, Va., a suburb of Washington. What Bailey learned from the episode informs his suspicion that the current strain of Ebola afflicting humans might be spread through tiny liquid droplets propelled into the air by coughing or sneezing. “We know for a fact that the virus occurs in sputum and no one has ever done a study [disproving that] coughing or sneezing is a viable means of transmitting,” he said. Unqualified assurances that Ebola is not spread through the air, Bailey said, are “misleading.”

[Dr. C.J.] Peters, whose CDC team studied cases from 27 households that emerged during a 1995 Ebola outbreak in Democratic Republic of Congo, said that while most could be attributed to contact with infected late-stage patients or their bodily fluids, “some” infections may have occurred via “aerosol transmission.”

Jonathan Ball dismisses fears of airborne Ebola:

While respiratory transmission has been shown in the laboratory, this was using a highly artificial animal model system, and most scientists concur that the virus is not spread through the respiratory route.

Similarly, in the only study of its kind, a report in the Journal of Infectious Diseases showed that the risk of contracting Ebola virus from fomites – particles loitering in the environment – was also very small. So all of the evidence suggests that if you avoid transferring virus from an infected individual or contaminated cadaver then the risk of infection is very low indeed.

But Allahpundit sees reason to worry about Ebola mutating into a more contagious virus:

The virus simply hasn’t had much of a chance to evolve while passing from person to person. It does now, with an outcome that’s yet to be determined. Just today, the World Health Organization walked back the conventional wisdom that the virus incubates in an infected person for no more than 21 days. Turns out that a man who’s gotten the disease and survived it can still pass it through his semen for up to 70 days afterward and possibly more than 90 days. Ebola could thus continue to thrive in Africa a la HIV as a killer STD.

Neo-Neocon notes something interesting too, per the bit in the excerpt about what it means to be “symptomatic”: Both Thomas Duncan, the Dallas Ebola patient, and the nurse in Spain had “slight fevers” when they first presented themselves to doctors. Fevers associated with Ebola typically run 101.5 or more. Could it be that victims with “slight fevers” are sufficiently symptomatic to pass the disease on?

Responding to those fears, Peter Barlow makes the point that just because a virus has an opportunity to mutate doesn’t mean it will:

While this certainly seems to be a real possibility, it is worth looking at what has happened with H5N1 avian influenza (“bird flu”). This highly contagious virus is relatively common in birds in Asia. But despite numerous human infections over the past 15-20 years, it has never mutated to spread through the air.

Alex Park has more on the WHO’s statement:

The sample sizes for these studies are extremely small, and it’s unclear just how great a risk the semen of surviving men poses in the weeks following their illness. Still, officials from the Centers for Disease Control and Prevention have recommended that they use condoms. And Doctors Without Borders—which has been on the front lines of the current outbreak since its early stages—is distributing condoms to survivors, according to a spokesperson for the group. …

Semen may not be the only bodily fluid through which a patient recovering from Ebola could pass on the disease. In 2000, researchers tested the fluids of a female Ebola survivor whose blood was already clear of the virus. Fifteen days after first falling ill, Ebola was still found in the woman’s breast milk. Her child eventually died of Ebola, though the researchers could not be certain the child got sick from feeding.

Meanwhile, Scott McConnell can’t believe we haven’t issued a travel ban yet:

In defense of the current, not very rigorous, regime, President Obama argues that “in recent months we’ve had thousands of travelers arriving from West Africa and so far only one case of Ebola.” But this was in the early stages of the epidemic, before the breakout of Ebola in West Africa’s cities. Does Obama really want thousands more West Africans flying here once Ebola cases number more than a million?

The answer appears to be yes. Mark Krikorian of the Center for Immigration Studies has pointed out that 13,000 visas for travel to America have been handed out in Liberia, Sierra Leone, and Guinea—which means that so long as such travelers don’t have a fever observed by the West African screeners when boarding and can get a ticket, they’re coming to the U.S.

Some issues are complicated, but this one seems simple. So long as the epidemic is raging, why should even a single traveler come here from the Ebola-infected countries?

Karen Weintraub outlines the case against such a policy:

Many public health experts who oppose the travel ban argue that it’s simply not practical. That includes Columbia University’s [Stephen] Morse, who describes himself as a “fence-sitter” on the issue but doesn’t support a travel ban right now because people with financial means can travel to an intermediate country before entering the United States. West Africa’s many porous borders make such travel even easier, he said.

It wouldn’t make sense to ban people who fly out of Senegal—where, like the United States, there has been only one case of Ebola, Morse said. But if one person with Ebola made it there, others could, too. A ban could also encourage people to lie about where they have been, Morse said: “One of the real concerns is that if you outlaw [travel], it will discourage people from coming forth with the truth.”

Mary Katherine Ham is characteristically skeptical of the government’s actions thus far:

It’s true that the administration has some kind of process in place to deal with the possibility of infected people getting to the U.S., albeit so bare and reactive a response that even senators don’t know anything about it. It’s also true the administration constantly uses incompetence as an excuse for its own failures, which it routinely does not find out about until they are reported in the media. It’s true that the CDC has done good and competent things in the past for public health. It’s also true that government health organizations have grossly mishandled anthrax, bird flu, and smallpox in the last year.

(Photo: In this handout from the Center for Disease Control, a colorized transmission electron micrograph of an Ebola virus virion is seen. By CDC via Getty Images)