Biomedical Engineering Reference
In-Depth Information
Some countries use the Bacille Calmette-Gu´rin (BCG)
vaccine to protect from tuberculosis. This vaccine has
demonstrated highly variable efficacy and most likely does
not prevent primary TB infection but does prevent
progression to miliary or meningeal TB. Individuals who
have received this vaccine may have false-positive first-step
TST, though this is not expected after 5 years following
vaccination. Generally, the second-step TST is more likely
to be positive in vaccinated individuals due to the boosting
effect. A positive TST in a person who received the BCG
vaccine more than 5 years before the test should be handled
in the same manner as any other positive reaction and that
person should be referred to a health care professional for
consultation prior to being granted access to the facility.
While TST is the mainstay of TB diagnostics in most
settings, there are several newly approved blood assays for
M. tuberculosis (BAMT) that may prove useful to augment
the TST. BAMT measure cytokine response and cell-
mediated immunity to the TB agents in samples of whole
blood. These tests are approved for use in lieu of TST and
do not require the use of a two-step approach. Generally,
a negative result on a BAMT test indicates that a person is
not infected with TB and these tests can also distinguish
between BCG vaccination and true TB infection. They may
also be useful to identify latent TB infection. One should
consider incorporating these tests into a comprehensive TB
screening program based on a
Recent data from the CDC's Division of Global
Migration and Quarantine has demonstrated that measles
continues to be a pathogen of importance for newly
imported NHPs. Measles infection in NHPs is a direct
result of exposure to infected humans or exposure to
monkeys that have been infected by humans. Therefore, all
NHP facilities should collaborate with their occupational
health unit to develop a measles control and prevention
program that is based on risk assessment and may include
immunization of both employees and animals. Based on
recommendations from the CDC's Advisory Committee on
Immunization Practices (
Advisory Committee on Immu-
nization Practices (ACIP), 2009
), adequate presumptive
evidence of immunity to measles is expected if a person has
either: (1) documented administration of two doses of live
measles virus vaccine; (2) laboratory evidence of immunity
or laboratory confirmation of disease; or (3) was born
before 1957.
Although seasonal influenza infections do not appear to
have high virulence in NHPs, it is recommended that NHP
personnel receive yearly vaccination to reduce the
frequency of transmission of the virus to co-workers and
NHPs. Facilities performing experimental infections with
influenza or any other infectious pathogen for which
a vaccine exists should ensure that all personnel who may
come in contact with infected animals are appropriately
vaccinated.
Hepatitis A vaccination is also a CDC recommended
practice for those people working with NHPs (
Advisory
Committee on Immunization Practices (ACIP) et al., 2006
).
Extensive serology from a variety of NHP species has
shown high simian hepatitis A seroprevalence (
Eichberg
and Kalter, 1980
) and outbreaks of hepatitis A among those
working with NHPs have been reported (
Dienstag et al.,
1976
). If personnel have not already been vaccinated as part
of their childhood vaccination series, then hepatitis
B vaccination should be considered for those working with
apes or with human serum or biological material. While the
risk of infection from New and Old World monkeys is
probably quite low due to the exceedingly low rate of
seroreactivity in these species, apes pose a much greater
risk and vaccination for those working with apes should be
strongly considered (
Heckel et al., 2001
).
Prophylactic rabies vaccination should be considered in
situations where large numbers of animals are housed
outdoors and may come in contact with potentially rabid
wildlife vectors such as raccoons or skunks. A combination
of rabies vaccination for colony animals and personnel
immunization can mitigate the risk of rabies exposure in
such situations. While human rabies vaccination does not
preclude the need for post-exposure rabies prophylaxis in
the event of an injury, it does reduce the risk of serious
illness and makes post-exposure prophylaxis easier to
manage (
Manning et al., 2008
).
comprehensive risk
assessment.
An employee serum bank should also be considered.
This is recommended by the CDC in situations where
a substantial risk of occupational exposure to specific
agents exists and where it may be possible to monitor
immunological response to that agent. Serum samples are
obtained at the time of employment and on a regular basis
thereafter and can be used to compare serum after an acute
illness to a baseline serum sample. Before implementing
a serum banking program it is important to consider the
potential uses as well as capabilities for storage, mainte-
nance of confidentiality, etc.
Personnel Immunization Program
While tuberculosis is the most important reverse zoonosis
to consider in the management of NHP colonies, viral
diseases also pose a significant risk to colonies. In order to
limit the transmission of viruses from personnel to colony
animals, an immunization program should be in effect. This
vaccination program can also be used to protect staff from
any infectious diseases that may be transmitted from NHPs
to personnel, either due to natural infection of the primates
or experimental inoculation. The design of a personnel
immunization program should be based on a risk assess-
ment of the species on nonhuman primate(s), facility, and
experimental use.
