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

incubation period of the disease. Therefore, the likelihood of entry of virus in the
commodity is assessed to be low but non-negligible.
17.2.2. Exposure assessment
Infected animals introduced into New Zealand could transmit the virus to other animals
through contact exposure involving minor abrasions of the oral mucosa or skin. However
this would be an inefficient method of transmission and is unlikely to lead to establishment
of the disease. The disease has never spread outside of the Americas, suggesting that there
are factors unique to endemic regions that are necessary for the establishment of the
disease. The disease is transmitted primarily by insect vectors. Whether any competent
vectors occur in New Zealand is not known. However, blackflies, commonly known as
‘sandflies’ belonging to the family Simuliidae are present. Therefore, the likelihood that
insect vectors in New Zealand could become infected and transmit the disease to naïve
animals in New Zealand is assessed to be very low but non-negligible.
17.2.3. Consequence assessment
If the virus became established in competent vectors in New Zealand, sporadic cases of
disease would be likely in animals, resulting in confusion with foot and mouth disease.
Expensive control procedures normally reserved for cases of foot and mouth disease might
be activated. There would also be losses due to interference with trade at least until foot
and mouth disease could be ruled out. Individual farmers would also incur costs due to
production losses.
The virus can cause disease in humans, as a result of direct contact or laboratory accidents
(Wilks 1994; Letchworth et al 1999; Swenson 2008). Many people in endemic areas have
antibody against the virus. Most cases of the disease go undiagnosed as the symptoms are
similar to influenza. It is likely that the establishment of the disease in New Zealand would
result in sporadic infections in humans during outbreaks of disease in livestock.
The exact host range of the virus is not known but infection or antibody production has
been described in pigs, white tailed deer, raccoon, skunk, bobtail, kinkajou, two- and threetoed
sloths, night monkeys, marmosets, agoutis and rabbits (Hanson & McMillan 1990). In
view of the wide host range it is possible that wild and feral animals could be infected but
indigenous birds are unlikely to be susceptible. Infections in feral and wild species are
likely to be subclinical. Therefore, the effects on the environment are likely to be
negligible.
In view of the above, the consequences of introduction and establishment are assessed to
be non-negligible.
17.2.4. Risk estimation
Since entry, exposure, and consequence assessments are all non-negligible, the risk
estimate for VS is non-negligible. Therefore it is classified as a hazard in the commodity
and risk management measures may be justified.
MAF Biosecurity New Zealand Import risk analysis: Llamas and alpacas from specified countries ● 59