(a) Because the infectious patient still remains in the house. In this case the healthy children must be kept from school until the patient has ceased to be infectious and disinfection has been thoroughly carried out; and for a further period longer than the longest known period of incubation of the disease in question (page [287]), a margin being left for contingencies. It would probably be 8 plus 2 weeks for scarlet fever.
(b) Children are kept from school for a period exceeding the longest period of incubation when the patient has been removed to hospital.
The table on page [322], modified from the Author’s School Hygiene, is introduced as furnishing a convenient summary of the subject.
Objection is sometimes taken to the exclusion of children under the above circumstances from school, on the ground that they continue to mix with others in the street or in neighbouring houses. Clearly, however, in a school-room, a suspected child may communicate infection to children coming from widely scattered streets, while out-of-doors the danger is comparatively slight, and among neighbours the danger is very limited in area.
It is assumed in the following table that all infected articles have been disinfected before the termination of the period of quarantine.
| DISEASE. | DURATION OF INFECTION. | DATE AT WHICH SCHOOL ATTENDANCE MAY BE RESUMED. | DURATION OF QUARANTINE OF CHILDREN EXPOSED TO INFECTION. |
|---|---|---|---|
| Scarlet fever | From 5 to 8 weeks; ceases when all peeling of the skin has been completed, and when the child is free from discharge from the nose or ear or sore places. | Not less than 8 weeks 14 days. from the beginning of the rash, and then only if no sore throat or sore places. | 14 days. |
| Diphtheria | At least 21 days; often much longer. Absence of infection should be confirmed by bacteriological tests. | Not less than 2 months, and not then if strength not recovered, or if any sore throat or any discharge from nose, eyes, ears, etc. | 12 days. |
| Small-pox and Chicken pox | About 4 to 5 weeks | When every scab has fallen off. | 18 days. |
| Measles | From 3 to 4 weeks; when all cough and branny shedding of skin has ceased. | Not less than 4 weeks from beginning of rash. | 21 days. |
| Rötheln (German measles) | 2 to 3 weeks | From 3 to 4 weeks from beginning of rash. | 21 days. |
| Mumps | About 21 days from the beginning. | 4 weeks from the beginning. | 24 days. |
| Whooping cough | 6 weeks from the beginning of whooping, or when the cough has quite ceased. | In about 8 weeks | 21 days. |
| Typhus and enteric fevers | 4 to 5 weeks | When strength sufficient. | 28 days. |
| Influenza | 2 to 3 weeks | 1 month | 10 days. |
School Closure is occasionally required to prevent the further spread of an infectious disease. This can be enforced on the order of any two members of the Local Sanitary Authority acting on the advice of the medical officer of health. This ought to be only occasionally necessary if notification of infectious diseases is strictly enforced, and if suspicious individual children are excluded from attendance at school. In diphtheria school closure may occasionally be rendered unnecessary by systematic bacteriological examination of the throats of children who had been exposed to infection (see page 299). School closure is more useful for country than for town schools, as in the former the homes of children are more remote from each other, but it is occasionally necessary for both. For measles school closure is specially indicated in Infants’ Schools. We have already seen that this disease is chiefly fatal when caught at a tender age (page [297]). The early closure of Infants’ Schools, and particularly of the Babies’ Class is therefore indicated. It is unfortunate that the attendance at school of children under six years of age is encouraged. Such children have more severe and more frequently fatal attacks of diphtheria, scarlet fever, measles, and whooping-cough; and these are frequently acquired at school.
International Quarantine was originally enforced against plague; but in many countries has been extended to other diseases, as cholera, yellow fever, typhus fever, small-pox and leprosy. In England cholera is the only disease in connection with which it has been in the past enforced. It has now been entirely abandoned. It consists in the compulsory isolation at the port of entry of all persons who have come from an infected district, or have been in contact with a case of the infectious disease against which quarantine is enforced, for a length of time which will enable it to be determined whether the persons detained are or are not incubating the disease. If this measure could be strictly enforced, and if infectious diseases were conveyed only by infectious persons, quarantine would undoubtedly be effective. But in practice quarantine cannot be enforced in Europe; and as it cannot be efficiently enforced it forms an ineffective and irrational derangement of commerce. Thus if plague prevailed in France it would be impracticable to detain for ten or twelve days every person entering England. Furthermore, in this instance, infection is brought by rats as well as persons; and measures effective for the latter do not prevent the former from importing infection. Because of its impracticability and of the disorganization of commerce which would be associated with any attempt to enforce it, England has abandoned quarantine and other countries are gradually following its example. England bases its action on the ground that (a) sanitation is the true chief means of defence, especially against cholera. It does not trust to this alone but to this along with (b) medical inspection at the ports, (c) and subsequent medical supervision of persons landed from suspected vessels. By these means a watch can be kept over persons who have been in contact with infection.
Regulations are issued at intervals by the Local Government Board requiring the disinfection by steam of all rags and similar materials imported from towns in which small-pox, cholera, etc., are prevalent.