Bma Illustrated Medical Dictionary

notably smallpox, tuberculosis, and mal-

aria. Other functions include sponsoring

medical research programmes, organiz-

ing a network of collaborating national

laboratories, and providing expert advice

and specific targets to its 160 member

states with regard to health matters.

worm infestation Several types of worm,

or their larvae, existing as parasites of

humans. They may live in the intestines,

blood, lymphatic system, bile ducts, or

in organs such as the liver. In many

cases, they cause few or no symptoms,

but some can cause chronic illness.

There are 2 main classes: roundworms

and platyhelminths, which are subdiv-

ided into cestodes (tapeworms) and

trematodes (flukes).

Worm diseases found in developed

countries include threadworm infestation,

ascariasis, whipworm infestation, toxocar-

iasis,liver-fluke infestation, and various

tapeworm infestations. Those occurring

in tropical regions include hookworm

infestation, filariasis, guinea worm dis-

ease,and schistosomiasis.

Worms may be acquired by eating

undercooked, infected meat, by contact

withsoil or water containing worm lar-

vae, or by accidental ingestion of worm

eggs from soil contaminated by infected

faeces. Most infestations can be easily

eradicated with anthelmintic drugs.

woundAny damage to the skin and/or

underlying tissues caused by an accident,

act of violence, or surgery. Wounds in

which the skin or mucous membrane is

broken are called open; those in which

they remain intact are termed closed.

WORM INFESTATION

Opioidwithdrawal symptoms start after

8–12 hours and may last for 7–10 days.

Symptoms include restlessness, sweat-

ing, runny eyes and nose, yawning,

diarrhoea, vomiting, abdominal cramps,

dilated pupils, loss of appetite, irritabil-

ity, weakness, tremor, and depression.

Withdrawal symptoms from barbiturate

drugsand meprobamatestart after 12–24

hours, beginning with tremor, anxiety,

restlessness, and weakness, sometimes

followed by delirium, hallucinations, and,

occasionally, seizures. A period of pro-

longed sleep occurs 3–8 days after onset.

Withdrawal from benzodiazepine drugs

may begin much more slowly and can

be life-threatening.

Withdrawal symptoms from nicotine

develop gradually over 24–48 hours and

include irritability, concentration prob-

lems, frustration, headaches, and anxiety.

Discontinuation of cocaine or amfe-

tamines results in extreme tiredness,

lethargy, and dizziness. Cocaine with-

drawal may also lead to tremor, severe

depression, and sweating.

Withdrawal symptoms from marijuana

include tremor, nausea, vomiting, diar-

rhoea, sweating, irritability, and sleep

problems. Caffeine withdrawal may lead

to tiredness, headaches,and irritability.

Severe withdrawal syndromes require

medical treatment. Symptoms may be

suppressed by giving the patient small

quantities of the drug he or she had been

taking. More commonly, a substitute drug

is given, such as methadonefor opioid

drugs or diazepamfor alcohol. The dose

of the drug is then gradually reduced.

wobble boardA balancing board used

during physiotherapyto improve mus-

cle strength and coordination in the

feet, ankles, and legs. A wobble board is

sometimes used after an ankle sprain.

wombSee uterus.

word blindnessSee alexia; dyslexia.

World Health Organization (WHO)

An international organization estab-

lished in 1948 as an agency of the

United Nations with responsibilities for

international health matters and public

health. The WHO headquarters are in

Geneva, Switzerland.

The WHO has campaigned effectively

against some infectious diseases, most

WOBBLE BOARD WOUND

W

Threadworm egg Larva inside egg

MICROSCOPIC VIEW OF WORM EGGS