produces small pinkish nodules on the head and trunk in juveniles, which appear for a few weeks and then regress, suggesting an intermittently reactivated localized infection that mostly remains dormant. In the second case, it has been found in small white pulmonary nodules on necropsy of many asymptomatic adults. These are both characteristic of EEHV2, EEHV3 and EEHV6. In a fatal attack, however, it manifests very quickly. In a number of cases, death has occurred within 24 hours of the onset of the infection, while other cases do not last longer than around five days. The virus attacks endothelial cells, rupturing capillaries and causing blood loss and haemorrhaging; once this reaches the heart, the haemorrhage kills quickly through shock. Symptoms include lethargy and an unwillingness to eat, a rapid heartbeat, and decreased blood-cell count, as well as cyanosis of the tongue, mouth ulcers, and oedema of the head and trunk. Rapid treatment with famciclovir, sustained for around a month, has appeared to cure eight calves infected with EEHV1; however, this treatment is very expensive, only partially effective, and relies on early identification of the infection. A polymerase chain reaction test on a blood sample from affected animals will confirm a suspected case by identifying the viral DNA, though it is now common to start famciclovir treatment at the earliest possible moment rather than waiting for confirmation of the case. Prior to the development of the test, or in circumstances where it is not available, the disease may be misdiagnosed as any of a number of other conditions which have a quick onset leading to rapid death, including encephalomyocarditis and salmonellosis. History The virus has been identified in the pulmonary nodules of African elephants as far back as the 1970s. The first recognised fatal case of EEHV in an Asian elephant was identified at the National Zoo in Washington, D.C., in 1995; testing on stored tissue samples was able to identify a number of earlier deaths as being due to the same virus. These cases have so far been identified as early as 1983. Since this date, there have been a total of 54 more cases in North America and Europe, nine of which were successfully treated. The May 2009 deaths of two calves at Whipsnade Zoo were not included in this calculation. This gives a fatality rate of over 80% among known symptomatic disease cases. In cases where antiviral medication