The pandemic of influenza that has during the last 12 months swept over the world started in China or Russia, where it is endemic, became epidemic, spreading to neighbouring countries along the ordinary channels of human intercourse, and from persons to persons, and finally took on pandemic proportions, passing over the whole world. The seriousness of the disease is shown by the mortality returns, which were  enormously increased everywhere.

Borough of Lambeth, London

As an example in London, the Borough of Lambeth may be taken: a fourth of the total deaths from all causes were due to influenza directly or indirectly. The age-period that suffered most was 25 to 40 years, though the age-periods 45 to 60 years and over 60 years also suffered severely. The sexes suffered equally, and the disease was spread throughout the borough, affecting no particular area, the inner, crowded districts suffering equally with the outer, less crowded districts.

Secondary cases were common, showing that the disease spread rapidly from person to person, the infection being most virulent during the first few hours of the disease (lasting in a less virulent form up to two days).

Whole households were hors de combat from the disease at one and the same time, and the staffs of workshops and factories practically depleted to half-shifts in the course of a few days.

Second attacks of the disease in the same persons were very few, if any. The incubation period is 48 hours. Morbidity must have been enormous, judging from mortality.

Preventive measures 

The Royal College of Physicians of London deemed the epidemic  warranted an authoritative statement on the subject. This was officially adopted by the Local Government Board  and circulated by the Board to all Medical Officers of Health,  with the Board’s other circulars dealing with the epidemic.

Public authorities have difficulties of administration in an influenza epidemic, on account of the very short incubation period of the disease and the rapidity with which the disease spreads from person to person.

The ordinary means of prevention do not apply in the sense that they apply to a disease like smallpox or scarlet fever, viz., (a) prompt notification; (b) isolation in a hospital; (c) disinfection; and (d) medical inspection of contacts.

It must be left to the individual to apply such measures to himself and his immediate surroundings, leaving to the public authorities the education side and the prevention of overcrowding in public places, vehicles, schools, etc., as well as in private premises used as common lodging houses and dormitories, etc., and the arranging for the proper ventilation at stated intervals of all such public or quasi-public places.

Ventilation of public or quasi-public places 

The Local Government Board introduced orders with a view to such ventilation being effected, known  as the Public Health (influenza) Regulations, 1918, and the Public Health Influenza Regulations  (No. 2), 1918, under which it is provided that, where the public are admitted to a place of public entertainment, the entertainment shall not be carried on for more than three hours consecutively, except in the case of a cinematograph exhibition, when the period of three hours may be extended to four hours; and further, that there shall be an interval of not less than 30 minutes between any two entertainments given at a place of public entertainment, to which the public is admitted, such interval to be for the purpose of the premises being effectually and thoroughly ventilated.

In the case of cinematograph exhibitions, children from a district wherein a public elementary school has been temporarily closed on account of the prevalence of influenza shall not be admitted in that district. 

School closure or exclusion from, or closure of places of public entertainment, exclusion from occupations, provision of proper nursing and medical assistance and of the more recently introduced domestic assistance or home-help are also matters for public authorities carrying out preventive measures  in dealing with influenza outbreaks that are epidemics or even pandemics. It must not be forgotten, however, how important are the personal or individual’s preventive measures.