[NOTE: I’d like to get the following information to Megyn Kelly, so she can do some further investigating on this point. Just emailing her seems futile, because it will get lost in the shuffle. Any ideas?]

Last night I watched Megyn Kelly’s interview with Dr. Rick Sacra, a Massachusetts doctor who contracted ebola in August while working in Liberia and who was flown to this country and recovered. His answers during this part of their exchange especially interested me:

DR. RICK SACRA, SURVIVED EBOLA: You know, [Kaci Hickox is] not ill. She’s not sick. She doesn’t have a fever. She doesn’t have other symptoms. And the science suggests that she’s really not a risk to anyone at this time. So in that sense, yes, I support her contention. She’s not a risk. KELLY: OK. SACRA: The reason you confine someone is because they’re a risk. She’s not a risk. KELLY: Here’s why people are concerned about her and other workers, I think. Because, first of all in 13 percent of an Ebola cases, you have no fever. So not having a fever isn’t the end-all tell-all about whether you have Ebola, right? SACRA: I think, you know, you can’t take a statistic like that in the absence of context. Sometimes people with Ebola at the end of their lives will no longer be able to mount a fever because they’re so weak. So when someone arrives at the tent for treatment in West Africa and they’re about to die, they may not be having a fever. Generally, healthy people like Miss Hickox, when they develop Ebola, they will have a fever. I think they will look behind those kinds of statistics. KELLY: OK. Understood.

That seemed plausible. However, Dr. Sacra didn’t cite from where he got his information. Perhaps there is a bona fide study that backs up what he’s saying, but I couldn’t find one (which of course doesn’t mean it doesn’t exist). What I did find was much more curious.

Before I go into that, let me say that for quite some time I’ve been doing online research about ebola itself, particularly transmission and early symptoms, as well as symptoms in general. I now have enough information to write about twenty posts, which means I despair of ever getting the information all out there, although I certainly plan to write a couple of lengthy ones.

But the summary version of what I’ve found is that the bulk of the information we have so far about ebola is based on data from past epidemics, plus animal research. The first source is hampered by the fact that this epidemic seems to be going differently and spreading further and faster, although what has caused that difference is as yet unclear . The second source is hampered by the usual caveat that a disease acts differently in different species, although some species (in the case of ebola, non-human primates) are more similar to humans in their responses than others.

There’s also a third problem with the data, which is that the the data from previous ebola outbreaks is sketchy, to say the least. That’s because record-keeping in medical facilities in those parts of Africa has been haphazard (plus some patients may not be coming in for care or even recognized as ebola patients):

Everything we know about Ebola since the disease’s two dozen or so outbreaks since 1976 comes not from a rich, deep database of scientific evidence that’s been carefully collected and recorded. With few formal health care systems in the areas hardest hit by the disease, there were no medical records, no charts and no standardized ways to document patients’ symptoms, vital signs, treatment regimens and whether or not they survived. Instead, much of our knowledge comes from the haphazard scrawl of doctors’ notes and their recollections about treatment and survival rates. But for the past 10 years at Kenema Government Hospital in Sierra Leone, the country’s Ministry of Health has been working with a group of international researchers to establish a meticulous medical records system””originally for patients with Lassa fever, another common infection in the region. So when the first Ebola patient walked through the door on May 25, the same procedures for documenting vital signs and treatment information stayed in place. Now, for the first time, doctors have a robust record of the first Ebola patients in the current outbreak treated at Kenema beginning in May””and the results of that record-keeping appear in the New England Journal of Medicine.

The article goes on to discuss some of the findings, none of which seem to deal with the main subject matter of this post: fever’s reliability as a symptom of ebola.

Back to Kelly, Sacra, and fevers—here’s a discussion of the study Kelly is presumably referring to when she asks the question of Dr. Sacra—the research that suggested that around 13% of ebola patients don’t appear to exhibit fever. Note, when you read it, how “garbage in, garbage out” the data seems, due mostly to lack of resources in that part of the world. Note, also, that “fever” was defined at a suitably low level (100.4) rather than the higher 101.5 level previous protocols have laid out [emphasis mine]:

The official assumptions about the frequency of fever in Ebola patients have not been challenged publicly. But Dr. Paul D. Stolley, former chairman of the University of Maryland’s Department of Epidemiology and Preventive Medicine, said the matter “requires further investigation.” Given the stakes, he said, the “absolute” assumption that Ebola can be spread only when an infected person displays fever should be reevaluated. “It may be true,” said Stolley, a member of the Institute of Medicine, part of the National Academies. “It just doesn’t sound very plausible to me.”… The authors of the recent World Health Organization study said they analyzed “a detailed subset of data” on confirmed and probable cases, including information from forms completed by doctors and other healthcare workers in the affected countries, indicating whether a patient had a fever and at what temperature and whether the reading was taken by armpit, by mouth or rectally. The study defined fever as 38 degrees Celsius ”” 100.4 degrees Fahrenheit. “To create the fullest possible picture of the unfolding epidemic,” the authors said, they collected additional information from “informal case reports” and other sources. The researchers described imperfections in some of the data. In a footnote, they wrote that “in practice, healthcare workers at the district level often do not have a medical thermometer and simply ask whether the person’s body temperature is more elevated than usual.” Yet the lead author, Dr. Christl Donnelly, a professor of statistical epidemiology at Imperial College London, stood by the findings on the prevalence of fever. Asked by email whether the study found no fever in 12.9% of confirmed and probable cases, Donnelly replied: “Yes.”… Three studies of previous outbreaks, cited in the same World Health Organization report, provide further grounds to question whether fever is a fail-safe signal. Researchers studying an outbreak in Uganda in late 2000 and early 2001 reported that “the commonest symptom ”¦ was fever, which occurred in 85% of the cases.” Another study of that outbreak, focusing on 24 confirmed cases of Ebola, found fever in 88%. The third study, which examined a 1995 outbreak in the Democratic Republic of Congo, found fever in 93% of 84 people who died and in 18 of 19 individuals who survived. Asked Friday how many people infected in the current outbreak should be expected to display fever, a CDC spokeswoman, Sharon Hoskins, said “the vast majority” would, but added that it was “impossible to give an exact percentage.” For doctors and nurses fighting the epidemic in West Africa, the risk of encountering Ebola in the absence of fever is more than academic. Dr. Nick Zwinkels, a Dutch physician, last month closed a hospital he had been running with a colleague in central Sierra Leone after five nursing aides contracted Ebola ”” possibly from unprotected contact with three patients who were not promptly diagnosed with the virus. Four of the nursing aides died, as did all three of the patients belatedly found to have Ebola. Interviewed by email, Zwinkels said that hospital staff members took the temperature of one of the doomed patients four times a day for three consecutive days, and the patient never showed a fever. The readings were taken by a digital thermometer placed in the armpit, he said. Based on what his staff observed, Zwinkels wrote, “it seems that only measuring the temperature as a form of triage is insufficient.” He added: “It seems that Ebola can present without fever especially in the first phase.” Zwinkels said that without fever as a trustworthy marker, it is difficult for medical professionals to treat the many West Africans suffering from everyday maladies… If Ebola cannot be readily identified, Zwinkels wrote, “Ebola patients will be admitted in the normal ward and possibly contaminating health staff and caretakers. This is why a lot of hospitals in West Africa are closed.

I wonder how Dr. Sacra would square those findings with his statements to Kelly about the absence of fever in ebola patients. I’ve seen no evidence that the absence of fever involves those in late stages only; on the contrary, experts in this article state that it tends more to involve the earlier stages (although there were also patients in late stages who lacked a fever, they seem to have never had a fever, which delayed their diagnoses, although after death they were finally documented as having had ebola). There is no discussion whatsoever of the sort of phenomenon Dr. Sacra describes.

Who is Dr. Sacra? According to this, he’s a family physician from Massachusetts. He doesn’t seem to be an ebola researcher or even an ebola expert, although I would imagine he certainly knows something about it, and not just from his personal experience of having suffered from the disease.

I had assumed that Sacra had gotten infected in Liberia treating ebola patients. But this was not the case:

Sacra, a family physician from Worcester, Massachusetts, wasn’t treating Ebola patients when he got infected. He was helping pregnant women. Like Writebol and Brantly before him, when a fever came on, he desperately hoped it was malaria and not Ebola.

I can only conclude that the most likely way Dr. Sacra contracted ebola was from treating a pregnant woman whose undiagnosed ebola was advanced enough to be contagious (diagnosis of ebola in pregnancy is easier to miss, by the way). Dr. Sacra’s story would appear to be evidence that ebola isn’t necessarily easy to diagnose or recognize even in contagious stages, and that symptoms do not always point so clearly to the disease, even when Western physicians are treating the patient in a hospital or clinic setting (much less when laypeople such as Thomas Eric Duncan are dealing with a similar patient presentation).

In terms of judgment, denial, and quarantines—it’s fascinating that Sacra, Brantly, and Writebol all thought and hoped they had malaria, a disease far more common in Africa, and certainly a possible diagnosis at the beginning. This shows that doctors and nurses are not always the best judges of what they have contracted. You know the old saying: a physician who treats himself has a fool for a patient.

[NOTE: As I said, I’ve got a lot more information on transmission and symptoms. Rather than deal with it all now, I’ll just offer a smattering.

This:

“It may not be absolutely true that those without symptoms can’t transmit the disease, because we don’t have the numbers to back that up,” said Beutler, “It could be people develop significant viremia [where viruses enter the bloodstream and gain access to the rest of the body], and become able to transmit the disease before they have a fever, even. People may have said that without symptoms you can’t transmit Ebola. I’m not sure about that being 100 percent true. There’s a lot of variation with viruses.”

What’s more, we assume that diarrhea and vomiting are always present, but apparently they’re not: