Introduction
Tuberculosis (TB) is an airborne infectious disease caused by
the tubercle
bacillus. TB cases can be broadly classified as "open"
and "non-open". Tiny tubercle bacilli can be seen, with
special staining, inside the sputum under direct microscopy
for "open" cases. "Open" cases are generally considered
infectious.
Not everyone exposed to an infectious TB
patient will be infected, and those infected may not develop
disease. The occurrence of infection and disease depends
on a number of factors, in particular the intensity of
exposure, and each individual’s body immunity. Only about
one out of ten infected individuals will develop disease
as a life-time risk. The disease may develop weeks, months,
years, or even decades after the infection. Unless disease
develops, the infected individual will remain well and
non-infectious like other healthy individuals.
When an inmate or a staff member in an institution
is diagnosed as having TB, the attending doctor should
notify the case to the Department of Health. In general,
contact examination will be conducted for close contacts
of an "open" case. However, the actual decision will depend
on careful assessment of the individual circumstances
which often vary. Advice may be sought from the nearby
chest clinics of the Department of Health.
Arrangement of contact screening
- The client and his/ her
relatives will be contacted by phone or interviewed by
a health nurse and explained of the need for any public
health actions including whether contact screening is
indicated.
- The supervisor of the institution
may be interviewed by the health nurse and explained of
the necessary public health actions. Information about
the staff/ inmate's close contacts, previous cases
of TB and the institutional environment may have to be
collected.
- Health information on TB
will be provided to the supervisor. This may be supplemented
by distribution of pamphlets, video show, or health talks,
depending on the actual needs.
- Staff or inmates with symptoms
suggestive of TB will be advised to seek prompt medical
consultation at the chest clinics.
- Advice will be provided
on the need for examination of asymptomatic contacts.
In case of need, X-ray examination may be arranged at
one of the X-ray centres.
Advice on prevention of TB
-
Symptom surveillance
At any time, staff or inmates with symptoms
suggestive of TB including persistent cough over 3 to
4 weeks, blood in sputum, weight loss, afternoon fever
and night sweating should seek prompt medical consultation.
-
Environmental hygiene
TB spreads mainly by air. It is essential to
maintain good indoor ventilation by means of natural ventilation
or mechanical ventilation such as exhaust fans. Furniture,
tables and walls do not play any significant role in the
transmission of the infection. Regular cleaning of the
environment should be done as general hygienic practice.
The dust filtres of air-conditioners should be cleansed as usual.
-
Healthy lifestyle
A healthy lifestyle helps to build up good body
resistance. This includes observation of good personal
hygiene, balanced diet, exercise, adequate rest, maintaining
a cheerful mood, quit smoking and refraining from alcohol.
-
Need to isolate TB patients?
"Non-open" TB cases are non-infectious.
For "open" cases, once anti-TB treatment is
started, the risk of spreading the infection is rapidly
reduced. For most TB patients, strict isolation is not
necessary. However, sick leave may be recommended for
an affected staff member when indicated (usually 2 weeks
or more). The staff member may resume usual work after
medical assessment for the rest of the treatment period.
The total duration of treatment usually lasts for 6 or
more months.
Conclusions
Prompt notification of TB cases inside institutions allows
proper assessment
and institution of appropriate public health actions,
which are important adjunctive measure in the overall
control of TB. However, with the high local prevalence
and variable latency of this disease, we have to maintain
our vigilance, even in absence of any
recent contact history.
TB telephone hotline:(852)
2572 6024
TB website: <http://www.info.gov.hk/tb_chest/en/index.htm>
