No cross-reactivity was observed with antisera against other species of herpesviruses, except a distinct reaction with a polyvalent anti-CeHV-1 antiserum due to the well-known cross-reactivity between HHV-1 and CeHV-1.
To discriminate between HHV-1 and HHV-2, type-specific PCR was performed according to the protocol of Piiparinen and Vaheri, using their published primers (2).
Together with the reaction with different HHV-1-specific antibodies, including subtype-specific monoclonal antibodies, this was a clear indication of HHV-1 virus's being the causative agent, excluding other possible primate herpesviruses.
Moreover, HHV-1 can naturally pass to primitive primates such as tree shrews (9).
In Old World primates, reports of human HHV-1 infections (10-12) indicate a virus-host relationship similar to that in humans, although sporadic fatal cases have been described, mainly in very young animals (13,14).