 |
Marburg and Ebola are filoviruses that cause hemorrhage, multiple organ failure, and high mortality rates. Diagnosis is with enzyme-linked immunosorbent assay, PCR, or electron microscopy. Treatment is supportive. Strict isolation and quarantine measures are necessary to contain outbreaks.
Epidemics have occurred rarely and sporadically. Most index cases involve exposure to nonhuman primates from sub-Saharan Africa or the Philippines. The vector and reservoir are unknown, although the Marburg virus has been identified in bats, and cases have occurred in people exposed to bats.
Human-to-human transmission occurs via skin and mucous membrane contact with an infected person or other primate. Aerosol transmission has been postulated.
Symptoms and Signs
After an incubation period of 5 to 10 days, fever, myalgia, and headache occur, often with abdominal symptoms (nausea, vomiting, pain, diarrhea) and upper respiratory symptoms (cough, chest pain, pharyngitis). Photophobia, conjunctival injection, jaundice, and lymphadenopathy also occur. Delirium, stupor, and coma may occur, indicating CNS involvement. Hemorrhagic symptoms begin within the first few days and include petechiae, ecchymoses, and frank bleeding around puncture sites and mucous membranes. A maculopapular rash, primarily on the trunk, begins around day 5.
During the 2nd wk of symptoms, either defervescence occurs and patients begin recovery, or patients develop fatal multiple organ failure. Recovery is prolonged and may be complicated by recurrent hepatitis, uveitis, transverse myelitis, and orchitis. Mortality ranges from 25 to 90% (higher with Ebola).
Diagnosis
Marburg or Ebola virus infection is suspected in patients with bleeding tendencies, fever, and travel to endemic areas or exposure to primates from these areas. CBC, routine blood chemistries, liver function and coagulation tests, and urinalysis are then done. Diagnostic tests include the enzyme-linked immunosorbent blood assay (ELISA) and PCR. The gold standard is detection of characteristic virions with electron microscopy of infected tissue (especially liver) or blood.
Treatment
No effective antiviral therapy exists. Treatment is supportive and includes minimizing invasive procedures and replacing depleted coagulation factors.
Prevention
A vaccine is currently in development. Mask-gown-glove precautions, thorough equipment sterilization, hospital closures, and community education have shortened epidemics. All suspected cases, including the cadavers, require strict isolation and special handling.
The US has strict quarantine procedures to prevent importation of infected monkeys.
Case reporting is required.
Last full review/revision December 2009 by Kenneth M. Kaye, MD
Content last modified December 2009
| |
|
