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

Since salmonellosis in camelids is rarely reported, much of the information given below is
extrapolated from other species, particularly cattle, in which enteric salmonellosis caused
by host adapted serovars is a very common form of the disease.
In enteric salmonellosis transmission is mainly by the oral route and factors such as
infecting dose, the particular strain and serovar, and various stress factors influence the
outcome of infection (Fenwick & Collett 2004). The incubation period in camelids is not
known, but in cattle it is as little as 15 minutes in newborn calves (Radostits et al 2007).
After oral infection, salmonellae colonise the distal ileum. Initial infection may be
followed by bacteraemia and dissemination to several organs. In the case of pregnant
animals, abortion may occur. Animals that recover from Salmonella infections may
become carriers for life, shedding organisms sporadically in their faeces. Excreted
organisms contaminate the environment and become a source of infection (Radostits et al
2007).
Carriers of infections can be detected by culturing faeces but, because excretion is
intermittent, repeated sampling and culture may be necessary. Serology may be useful but
is best applied on a herd basis (Davies 2008; Veling et al 2002). No practical serological
method exists for detecting individual carrier animals (Hansen et al 2006).
29.1.5. Hazard identification conclusion
Salmonellosis is very rarely reported in camels. However, assuming that they could, like
other animals, become carriers of exotic Salmonella serovars such as S. Dublin or S.
Typhimurium DT104 that could be harmful to animal industries or to humans, salmonellae
are considered to be potential hazards in the commodity.
29.2. RISK ASSESSMENT
29.2.1. Entry assessment
Salmonella spp. have a world-wide distribution and the range of serovars varies from one
country to the next. Assuming that subclinical carriers can occur, the likelihood that
imported camelids could introduce exotic Salmonella serovars is assessed to be nonnegligible.
29.2.2. Exposure assessment
Imported camelids will be introduced onto premises where New Zealand camelids and
other animals are present. Assuming that camelids that are enteric carriers of salmonellae
will excrete organisms in their faeces as other carrier animals do, the likelihood of
exposure and infection of indigenous animals is assessed to be non-negligible.
29.2.3. Consequence assessment
Introduction of infected animals would be likely to result in spread of the organisms
throughout the country due to movement of animals and people. The potential for spread is
illustrated by the spread of S. Brandenberg in sheep and humans (Clark et al 2004; Clarke
& Tomlinson 2004). Another example was the spread of S. Typhimurium DT160 following
its first detection in sparrows and humans (Alley et al 2002). It spread rapidly to become
the most widely isolated Salmonella spp. as can be seen in the data reported in the ESR
database (ESR 2009). Introduction of new serovars may result in production losses in
108 ● Import risk analysis: Llamas and alpacas from specified countries MAF Biosecurity New Zealand