Trachoma is an infectious eye disease that can
eventually cause blindness if left untreated. Infection of the eyes with the
bacteria Chlamydia trachomatis usually occurs in childhood, but
infected people generally do not develop severe sight problems until adulthood. It is therefore essential that
you are able to identify the early signs of the disease and treat patients
appropriately in order to avoid severe complications developing later in life.
First, we will describe the
infectious agents that cause trachoma, their modes of transmission and the
clinical manifestations of the disease. This knowledge will enable you to
identify people with symptoms, grade the signs according to a classification of
severity, and decide whether you should treat patients yourself or refer them
to a health centre or hospital. Then you will learn how to give health
education about trachoma and its prevention in your community.
What causes trachoma?
Identify the areas labelled as the conjunctiva and the
cornea. In the initial stages of trachoma, the bacteria Chlamydia
trachomatis primarily infect the conjunctiva (pronounced
‘kon-junk-tie-vah’). This is a thin clear membrane that covers the inner
surface of the eyelid and the white part of the eyeball. First it becomes itchy
and inflamed (red, swollen and painful); later it becomes scarred and the
eyelashes turn inwards.
The cornea is
the thick transparent tissue over the front part of the eye, covering the
white, black and coloured areas. The damage to the cornea is not due to the
bacteria, but by persistent scratching from the eyelashes, which have turned
inwards due to scarring in the conjunctiva.
Prevention and control of trachoma
There are four major components
for the prevention and control of trachoma at community level, which are
represented by the letters SAFE (see Box 39.2 and the
details below the box).
Box 39.2 SAFE strategy for the prevention and control of trachoma
S = Surgical
treatment for trichiasis to stop eyelashes rubbing the cornea
A = Antibiotic
treatment of active cases of trachoma by tetracycline 1% ointment applied to
the eyes
F = Faces and hands
washed regularly to prevent infection spreading
E = Environmental
sanitation and safe water supply.
Surgical treatment
A simple surgical procedure can
save a patient from becoming blind. Surgery can be carried out at the health
centre by trained nurses and may simply involve turning out the eyelashes that
are scarring the cornea. Your role is to reassure and refer patients with
Grades 3 to 5 (i.e. trachomatous scarring, trachomatous trichiasis, or corneal
opacity) for immediate surgery. Explain that the operation is very simple,
quick and safe, and it will greatly reduce the discomfort in their eyes and
prevent further damage from occurring.
Antibiotic treatment
You are expected to treat grade 1
and grade 2 active trachoma (i.e. people with trachomatous
follicles and trachomatous inflammation in at least one eye) in the community.
You should show parents how to administer tetracycline 1% ointment onto the
conjunctiva inside the eyelids twice every day for six weeks. If you identify
two or more family members with trachoma, treat the whole family.
If you are informed by the
District Health Office that trachoma is a major concern, you may be advised to
treat all the children in your community as a preventive measure. If this is
the case, treat all children with tetracycline eye ointment for five
consecutive days in a month, and repeat the same procedure for six consecutive
months. Alternatively, a doctor may prescribe the oral antibiotic azithromycine
(20 mg/kg bodyweight) as a single dose in place of tetracycline to treat the
whole community.
Face washing
Educate all families,
particularly mothers of children (Figure 39.10), by going house to house to
teach them the importance of regular washing of face and hands, ideally using
soap. Go to schools to teach children there in a large group that washing
regularly prevents the transmission of trachoma from person to person. Everyone
should learn the habit of washing their hands with soap and water in the early
morning before they touch their eyes, before and after eating or preparing
food, and after using the latrine.
Adapted from: http://labspace.open.ac.uk
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