The Ebola Virus: Primer and Urologic Manifestations

The Ebola virus causes hemorrhagic fever and can lead to death in a high proportion of patients. The most recent outbreak in Liberia, Guinea and Sierra Leone has affected more than 1,300 people and killed over 700 in the past year. As our infected, American colleagues return home for treatment, we take this opportunity to review the Ebola virus and urologic complications.

Ebola Virus Basics

Ebola virus.

The Ebolavirus genus belongs to the Filoviridae family of RNA viruses -- named from the Latin word fÍlum, or thread, for its unique morphology. The other member of the Filoviridae family is the Marburgvirus. There are five members of Ebolavirus and four cause hemorrhagic fever in humans. The severe infection is propagated by rapid viral replication in host macrophages (immune cells), subsequent immunosuppression of the host and vascular dysfunction.
The first recognized fioviral hemorrhagic fever in humans was due to the Marburg virus and occurred in Germany and Yugoslavia in 1967. Since then, more than 30 separate outbreaks, individual cases and laboratory infections have led to about 2,500 confirmed cases. Mortality rates vary by the strain of virus, but range from 50-90%.
The virus is transmitted by contact with infected body fluids (blood, urine, stool, semen, saliva, breast milk and tears). It is believed to be transmitted from animals to humans, with bats the most likely reservoir.

Ebola virus lifecycle from the Centers for Disease Control and Prevention (www.cdc.gov).

Clinical Features

The incubation period (from infection to symptoms) can vary from 3-21 days. The initial symptoms are typically "flu-like" and can include: fever, chills, fatigue, headache, myalgias, nausea, vomiting and diarrhea. These symptoms often mimic malaria; and in areas where malaria is endemic (like sub-Saharan Africa), these non-specific symptoms can lead to a delay in diagnosis.
Fever, rash and thrombocytopenia (low platelet counts) are the classic symptoms described in all cases of infection. The fever is typically very high, between 102-104°F (39-40°C). Rash usually appears early in the course and is described as nonpruritic, erythematous and maculopapular that progresses from focal to generalized, to confluent. Thrombocytopenia appears early in the course of infection, and platelet counts continue to decline and remain low in fatal cases. Thrombocytopenia can manifest as "hemorrhage," which usually manifests as bleeding in the conjunctiva (eyes), easy bruising and bleeding from venipuncture sites. Fulminant hemorrhage or "bleeding out" is very rare and is usually localized to the gastrointestinal tract.
Other signs and symptoms can appear depending on the severity of infection. These can include sore throat, enlarged lymph nodes, hepatomegaly (enlarged liver) with abnormalities in liver function tests, loss in appetite, jaundice, and hiccups (which tend to be an end-stage symptom). Fatal cases usually progress through hypotension and shock to coma and death within two weeks of presentation. Survivors are debilitated by the disease for weeks to months. These persistent symptoms include fatigue, anemia, weight loss, joint pain, hair loss and painful skin sloughing for weeks after infection.

Signs and symptoms of disease caused by Ebola and Marburg viruses.  From Hartman et al, 2010.

Urologic Signs and Symptoms

While these viruses can affect the entire body, the urologic manifestations are typically rare. These include renal failure and hematuria. Loss in renal function is present in most cases and is manifest by a transient rise in creatinine and BUN with concomitant decrease in urine output. However, oliguria (severely low urine output) and complete renal failure usually only occur in fatal cases. Bleeding from mucosal surfaces, including the gastrointestinal and genitourinary system, is extremely common. While hematuria is common, bleeding from the gastrointestinal tract is usually more severe and pronounced. Treatment of urologic complications is typically supportive with intravenous hydration, support of renal function and correction of metabolic abnormalities. Hematuria is also managed conservatively -- no cases of clot retention are described.

-----
References and more details can be found at:

Hartman AL, Towner JS, Nichol ST.  Ebola and marburg hemorrhagic fever.  Clin Lab Med. 2010 Mar;30(1):161-77. doi: 10.1016/j.cll.2009.12.001.

Kortepeter MG, Bausch DG, Bray M.  Basic clinical and laboratory features of filoviral hemorrhagic fever.  J Infect Dis. 2011 Nov;204 Suppl 3:S810-6. doi: 10.1093/infdis/jir299.

http://www.cdc.gov/vhf/ebola/index.html

http://en.wikipedia.org/wiki/Ebola_virus_disease