I started reading The Hot Zone, but have had to take a temporary hiatus from reading it due to school work and such, but the book promtped this question from me. Let us say that a patient was to go to an emergency room in America and was in fact infected with the Ebola virus. The person is throwing up blood and such. How long would it take for them to be diagnose them with Ebola? I don’t think it would be what would be immediately suspected and I don’t know if it is a standard part of any type of blood testing.
The filoviruses (encompassing the species of Ebola as well as the Marburg virus) which cause hemorrhagic fevers are quick replicating and the human body’s immune response to them is incomplete, so early diagnosis via detection of antibodies in the blood is unreliable. The viruses themselves, however, have very distinctive apperances (the Marburg virions are long, stringy structures, whereas the Ebola species have a characteristic “shephard’s hook” conformation), so if virions can be isolated out of a blood sample and viewed via electron micrography it’s pretty obvious what they are. Good luck getting access to such equipment or rapid transport of samples to a qualified lab from the locales where outbreaks occur, though.
From the onset, the early symptoms of hemorrhagic fevers (fever, diarrhea, joint pain, et cetera) can easily appear to be other very common illnesses like typhoid and malaria, and by the time they’ve developed to detectable levels in the bloodstream they’ll already be manifesting the more horrific symptoms of organ necrosis and internal hemorrhaging. Major symptoms (vomiting blood and the like cited by the o.p.) usually appear within a week after the incubation period (3-21 days, depending on species any type/intensity of contact), and the disease usually progresses to completion by two weeks after the incubation.
There is no cure and no effective treatment for the diesease other than to provide fluids, electrolytes, and coagulation serums intraveneously and otherwise keep the patient maintained while the disease wrecks its course. The diseases have a 50%-90% mortality rate for primary infection (depending on strain), with lower mortality for secondary infections, suggesting that any outbreak would be naturally limited in scope to initial infectees and caregivers. There is no evidence of aerosol transmission of any of the filoviruses, and barrier isolation and UV/chemical disinfection methods are effective in preventing transmission of the disease when executed stringently. In general, filoviruses are too virulent in their expressed state, and have too low a transmissability in their incubative state, to cause a mass outbreak even in a developed area, much less in the logistically isolated regions where it appears natively. Although its descriptions of the pathology and progress of hemorrhagic fevers are accurate, The Hot Zone is somewhat hyperbolic in its warning of the potential for epidemic such viruses may cause.
A patient attending a U.S. or European hospital would immediately be isolated if they showed signs of expectorating or vomiting blood regardless of whether they were suspected of harboring a hemorrhagic fever or otherwise. No doubt a complete workup including blood test would be performed before the patient would be permitted out of isolation. (I say this, of course, in the aftermath of our jet-setting Tuberculosis Andrew, but one would hope that doctors would and could be somewhat more persuasive with a patient who was literally coughing up blood.) I would suspect that after initial serological testing ruled out standard antigens that detail blood testing would be done while the patient remained in quarantine.
Stranger
The Horse’s Mouth indicates that a positive diagnosis of Ebola requires the use of a variety of tests, including ELISA and PCR, and that this would take a matter of days. Symptoms in the first several days are non-specific (rash, fever). And you would need strain-specifc ELISA and PCR tests to determine which strain is involved. Ditto for Marburg, which is really just the mildest of the Sisters Ebola.
Viruses are hard to diagnose, as they are very, very small, and need to be cultured. That, and they need to present a very distinctive antibody profile. Which only reaslly works if you have a good reference probe.
Once the initial phase of the disease is over, the symptoms might be somewhat more, errrr, distinctive. But not every case results in the dramatic bloody-vomit-gut-sloughing nightmare described in Preston’s book. A patient can expire with extended fever and internal bleeding, with little external signs beyond the rash.
The two factors that promote the outbreaks of Ebola are 1)the recycling of needles and 2)inferior sanitation protocols. These factors have turned clinics into foci for the amplification of the outbreaks. Also, tribal traditions in handling the dead serve as effective transmission modes that amplify the infection within tribes and families.
But I’ll stop now, as I find myself re-writing Preston’s book. 