Pathophysiology Of Bacillary Dysentery Definition....
Bacillary dysentery is caused by one of three germs, all members of the shigella family: Shigella soonish. jlexneri and Shshag. (Sonne, Flexner and Shiga were the names of three doctors concerned with the discovery of these germs.) Sh. sonnei is the commonest cause of bacillary dysentery in Britain, but in tropical countries Sh. flexneri and Sh. shigae are commoner, and these two usually cause much more severe illnesses than Sh. sonnei.
Sonne dysentery is usually spread by direct contact. A child soils its hands at toilet and then touches another child's hand: the second child lifts its hand to its mouth and the dysentery germs enter. A very small dose of Shigellae sonnei is enough to cause infection. Sh. flexneri and Sh. shigae are usually spread by food or water. But, in all three types, infection means that the germ has been conveyed from the faeces of one person to the mouth of another.
Symptoms. The incubation period is from one or two days to a week. The main symptom is diarrhoea. This may be mild or very severe. Espe¬cially in Sonne dysentery, the patient may have only one or two loose motions. Nurses must be very careful about such incidents: they can so easily be infected, become carriers and not realize it. At the other extreme, especially with infections due to Shigella flexneri or Sh. shigae, the diarrhoea may be overwhelmingly severe, with much blood passed per rectum, so that the patient rapidly becomes prostrated and collpsed. Such patients have much abdominal pain and vomiting and become rapidly dehydrated.
Course. In Britain and most temperate countries, bacillary dysentery is a mild, often trivial illness over in a day or two. Only in young babies or in frail old patients is it a dangerous condition. In the tropics it is a severe, debilitating illness lasting for one or two weeks and sometimes fatal.
Diagnosis. Specimens of faeces or rectal swabs should be sent to the laboratory. If the disease, seems to be food-borne, samples of the sus¬pected food should also be sent.
Treatment. Mild cases require no special treatment and this refers to most cases of Sonnie dysentery. Nurses must be very careful when dis¬posing of farces or soiled nappies, or even when changing bedclothes or ,,ashing the patient (see Chapter 35). For severe cases, especially in the tropics, treatment is by replacement of fluid, usually by intravenous infusions. Blood transfusions may be required for the worst cases.
If the patient can take liquid by mouth, he should be given drinks of glucose-saline flavoured with lemon or other fruit juices. Babies should be given plain 1/5 normal glucose-saline, but no milk till the diarrhoea has stopped. Diet must be built up gradually as the patient recorder.
Although sulphonamides and antibiotics do help to clear the bowel of dysentery germs, the germs can quickly become resistant to the drugs which are then useless. Moreover these resistant germs can transfer their resistance to other bowel germs. This transferable drug resistance is one of the great hazards of antibiotic therapy. It is better not to use antibiotics for dysentery except in very severe cases.
Prevention of bacillary dysentery depends on strict personal hygiene, aseptic nursing, good sanitation and careful food-handling. This can be difficult even in fully developed countries: in undeveloped tropical countries it is a major public-health problem.
Bacillary dysentery is caused by one of three germs, all members of the shigella family: Shigella soonish. jlexneri and Shshag. (Sonne, Flexner and Shiga were the names of three doctors concerned with the discovery of these germs.) Sh. sonnei is the commonest cause of bacillary dysentery in Britain, but in tropical countries Sh. flexneri and Sh. shigae are commoner, and these two usually cause much more severe illnesses than Sh. sonnei.
Sonne dysentery is usually spread by direct contact. A child soils its hands at toilet and then touches another child's hand: the second child lifts its hand to its mouth and the dysentery germs enter. A very small dose of Shigellae sonnei is enough to cause infection. Sh. flexneri and Sh. shigae are usually spread by food or water. But, in all three types, infection means that the germ has been conveyed from the faeces of one person to the mouth of another.
Symptoms. The incubation period is from one or two days to a week. The main symptom is diarrhoea. This may be mild or very severe. Espe¬cially in Sonne dysentery, the patient may have only one or two loose motions. Nurses must be very careful about such incidents: they can so easily be infected, become carriers and not realize it. At the other extreme, especially with infections due to Shigella flexneri or Sh. shigae, the diarrhoea may be overwhelmingly severe, with much blood passed per rectum, so that the patient rapidly becomes prostrated and collpsed. Such patients have much abdominal pain and vomiting and become rapidly dehydrated.
Course. In Britain and most temperate countries, bacillary dysentery is a mild, often trivial illness over in a day or two. Only in young babies or in frail old patients is it a dangerous condition. In the tropics it is a severe, debilitating illness lasting for one or two weeks and sometimes fatal.
Diagnosis. Specimens of faeces or rectal swabs should be sent to the laboratory. If the disease, seems to be food-borne, samples of the sus¬pected food should also be sent.
Treatment. Mild cases require no special treatment and this refers to most cases of Sonnie dysentery. Nurses must be very careful when dis¬posing of farces or soiled nappies, or even when changing bedclothes or ,,ashing the patient (see Chapter 35). For severe cases, especially in the tropics, treatment is by replacement of fluid, usually by intravenous infusions. Blood transfusions may be required for the worst cases.
If the patient can take liquid by mouth, he should be given drinks of glucose-saline flavoured with lemon or other fruit juices. Babies should be given plain 1/5 normal glucose-saline, but no milk till the diarrhoea has stopped. Diet must be built up gradually as the patient recorder.
Although sulphonamides and antibiotics do help to clear the bowel of dysentery germs, the germs can quickly become resistant to the drugs which are then useless. Moreover these resistant germs can transfer their resistance to other bowel germs. This transferable drug resistance is one of the great hazards of antibiotic therapy. It is better not to use antibiotics for dysentery except in very severe cases.
Prevention of bacillary dysentery depends on strict personal hygiene, aseptic nursing, good sanitation and careful food-handling. This can be difficult even in fully developed countries: in undeveloped tropical countries it is a major public-health problem.
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