Import risk analysis: Llamas (Lama glama) and alpacas (Vicugna ...

10. Bovine herpesvirus type 1
10.1. HAZARD IDENTIFICATION
10.1.1. Aetiological agents
Family: Herpesviridae; Subfamily: Alphaherpesvirinae; Genus: Varicellovirus; Species:
bovine herpesvirus 1 (BHV-1) (Davison et al 2005).
BHV-1 is associated with infectious bovine rhinotracheitis (IBR) and infectious pustular
vulvovaginitis/infectious pustular balanoposthitis (IPV/IPB). Subtypes BHV-1.1 and BHV-
1.2 can be identified by restriction endonuclease analysis of DNA (Engels et al 1981;
Wentink et al 1993; Babuik et al 2004). Rhinitis and respiratory signs are associated with
subtype 1.1, pustular vulvovaginitis and balanoposthitis is associated with subtype 1.2.
Subtype 1.2 strains can be further classified as BHV-1.2a and BHV-1.2b strains. Some
subtype 1.1 and 1.2a strains are abortifacient (Miller et al 1991). Subtype 1.2b strains are
associated with respiratory and genital infections but not with abortions (Miller et al 1991;
van Oirschot 1995).
Table 2 Bovine herpesviruses
Type
Syndrome
IBR IPV/IPB Abortion
BHV-1.1 + - +
BHV-1.2a + + +
BHV-1.2b + + -
10.1.2. OIE list
Infectious bovine rhinotracheitis and infectious pustular vulvovaginitis are listed as
diseases of bovidae.
10.1.3. New Zealand status
Only BHV-1.2b has been isolated in New Zealand (Wang et al 2006). Abortions caused by
bovine herpesviruses have not been seen in New Zealand (Horner 1990; Fairley 1996), and
an attempt to cause abortion by experimental infection with the New Zealand strain of the
virus was unsuccessful (Durham et al 1975). At the present time identification of
abortifacient strains of the virus from either subtype 1 or 2 strains would require
experimental infection of pregnant cows and a more pragmatic approach is to regard BHV-
1.1 and BHV-1.2a as exotic organisms. Abortifacient strains are classified as unwanted
notifiable organisms (MAF 2009).
10.1.4. Epidemiology
IBR/IPV has a world-wide distribution. Australia reports that BHV-1.2b is present but
BHV-1.1 and BHV-1.2a has never occurred (Animal Health Australia 2010).The virus is
endemic and widespread in New Zealand (Neilson & Grace 1988). Both the IBR and the
IPV syndrome have been described (Horner 1990; Fairley 1996; Vermunt & Parkinson
2000). However, in the vast majority of cases there are no, or only mild, clinical signs
(Vermunt & Parkinson 2000).
MAF Biosecurity New Zealand Import risk analysis: Llamas and alpacas from specified countries ● 31