Current Trends Recommendations for Preventing Possible
Transmission of Human T-Lymphotropic Virus Type III/
Lymphadenopathy-
Associated Virus from Tears
Human T-lymphotropic virus type III/lymphadenopathy-associated
virus (HTLV-III/LAV), the etiologic agent of acquired
immunodeficiency
syndrome (AIDS), has been found in various body fluids, including
blood, semen, and saliva. Recently, scientists at the National
Institutes of Health isolated the virus from the tears of an AIDS
patient (1). The patient, a 33-year-old woman with a history of
Pneumocystis carinii pneumonia and disseminated Mycobacterium
avium-intracellulare infection, had no ocular complaints, and her
eye
examination was normal. Of the tear samples obtained from six
other
patients with AIDS or related conditions, three showed equivocal
culture results, and three were culture-negative.
The following precautions are judged suitable to prevent spread
of
HTLV-III/LAV and other microbial pathogens that might be present in
tears. They do not apply to the procedures used by individuals in
caring for their own lenses, since the concern is the possible
virus
transmission between individuals.
Health-care professionals performing eye examinations or
other procedures involving contact with tears should wash
their hands immediately after a procedure and between
patients. Handwashing alone should be sufficient, but
when
practical and convenient, disposable gloves may be worn.
The
use of gloves is advisable when there are cuts, scratches,
or
dermatologic lesions on the hands. Use of other
protective
measures, such as masks, goggles, or gowns, is not
indicated.
Instruments that come into direct contact with external
surfaces of the eye should be wiped clean and then
disinfected by: (a) a 5- to 10-minute exposure to a fresh
solution of 3% hydrogen peroxide; or (b) a fresh solution
containing 5,000 parts per million (mg/L) free available
chlorine--a 1/10 dilution of common household bleach
(sodium
hypochlorite); or (c) 70% ethanol; or (d) 70% isopropanol.
The device should be thoroughly rinsed in tap water and
dried
before reuse.
Contact lenses used in trial fittings should be
disinfected
between each fitting by one of the following regimens:
Disinfection of trial hard lenses with a commercially
available hydrogen peroxide contact lens disinfecting
system currently approved for soft contact lenses.
(Other hydrogen peroxide preparations may contain
preservatives that could discolor the lenses.)
Alternatively, most trial hard lenses can be treated
with the standard heat disinfection regimen used for
soft lenses (78-80 C (172-176 F) for 10 minutes).
Practitioners should check with hard lens suppliers
to
ascertain which lenses can be safely heat-treated.
Rigid gas permeable (RGP) trial fitting lenses can be
disinfected using the above hydrogen peroxide
disinfection system. RGP lenses may warp if they are
heat-disinfected.
Soft trial fitting lenses can be disinfected using
the
same hydrogen peroxide system. Some soft lenses have
also been approved for heat disinfection.
Other than hydrogen peroxide, the chemical disinfectants
used
in standard contact lens solutions have not yet been
tested
for their activity against HTLV-III/LAV. Until other
disinfectants are shown to be suitable for disinfecting
HTLV-III/LAV, contact lenses used in the eyes of patients
suspected or known to be infected with HTLV-III/LAV are
most
safely handled by hydrogen peroxide disinfection.
The above recommendations are based on data from studies
conducted
at the National Institutes of Health and CDC on
disinfection/inactivation of HTLV-III/LAV virus (2-4). Additional
information regarding general hospital and laboratory precautions
have
been previously published (5-9).
Reported by the U.S. Food and Drug Administration; National
Institutes
of Health; Centers for Disease Control.
Editorial Note
Editorial Note: All secretions and excretions of an infected person
may
contain lymphocytes, host cells for HTLV-III/LAV; therefore,
thorough
study of these fluids might be expected to sometimes yield this
virus.
Despite positive cultures from a variety of body fluids of infected
persons, however, spread from infected persons to household
contacts who
have no other identifiable risks for infection has not been
documented.
Furthermore, there is no evidence to date that HTLV-III/LAV has
been
transmitted through contact with the tears of infected individuals
or
through medical instruments used to examine AIDS patients.
References
Fujikawa LS, Salahuddin SZ, Palestine AG, et al. Isolation of
human T-cell leukemia/lymphotropic virus type III (HTLV-III)
from
the tears of a patient with acquired immunodeficiency syndrome
(AIDS). Lancet (in press).
Resnick L, Veren K, Salahuddin SZ, Markham PD. Personal
communication.
Martin LS, McDougal JS, Loskoski SL. Disinfection and
inactivation of the human T lymphotropic virus type
III/lymphadenopathy-associated virus. J Infect Dis
1985;152:400-3.
Spire B, Barre-Sinoussi F, Montagnier L, Chermann JC.
Inactivation of a new retrovirus (lymphadenopathy-associated
virus) by various agents (chemical disinfectants). Lancet
1984:8408;899-901.
CDC. Acquired immune deficiency syndrome (AIDS): precautions
for
clinical and laboratory staffs. MMWR 1982;31:577-80.
CDC. Prevention of acquired immune deficiency syndrome (AIDS):
report of inter-agency recommendations. MMWR 1983;32:101-4.
CDC. Acquired immunodeficiency syndrome (AIDS): precautions
for
health-care workers and allied professionals. MMWR
1983;32:450-1.
CDC. Update: prospective evaluation of health-care workers
exposed via parenteral or mucous-membrane route to blood or
body
fluids from patients with acquired immunodeficiency syndrome.
MMWR 1985;34:101-3.
CDC. Hepatitis B vaccine: evidence confirming lack of AIDS
transmission. MMWR 1984;33:685-7.
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