Observations on the Meningococcus Carrier-Rate in relation to density of population in Sleeping Quarters

Abstract

1. A high meningococcus carrier-rate in a military unit denotes that dangerous overcrowding exists in this unit.2. Severe overcrowding (i.e. when beds are less than 1 foot apart) is usually accompanied by a carrier-rate (serological) of at least 20 per cent.(Twenty per cent. is the danger line indicated in the War Office Memorandum on Cerebro-spinal Fever, March 1917.)3. A carrier-rate of this height will usually imply that the mobilization standard of 40 square feet has been infringed, and also that beds are less than 1 foot apart.4. A carrier-rate of 20 per cent. (without awaiting the occurrence of any actual cases of the disease) should be regarded as a signal for prompt and effective action to abolish overcrowding, and to improve ventilation, and to increase the distance between the beds to at least 2½ feet.5. The distance between beds is of paramount importance.6. Carrier-rates of between 10 and 20 per cent. are unsatisfactory and imply a certain degree of overcrowding. They must be watched with suspicion, and the mobilization standard strictly enforced.7. Under the same conditions of overcrowding “non-contact” carrier-rates are the same as “contact” carrier-rates.8. Quite a moderate degree of “spacing out” of beds, combined with simple methods for improving ventilation are highly efficient agents in reducing high carrier-rates.9. When, however, a unit shows a high carrier-rate, insistence on the restoration of the mobilization standard is not sufficient.“Spacing out” must be carried further; and a distance of at least 2½ feet between beds insisted on.The “peace” standard of 3 feet between beds and 60 square feet of floor space with 600 cubic feet of air space would, of course, be still more effective.10. The mobilization standard, introduced for a grave emergency, is the lowest possible concession to military necessity, which can be allowed with safety.

Meningococcus Carrier Rates and Meningitis Incidence 1

“…." (7), and that 22% of civilians examined in an outpatient infirmary "although they had no relation to cerebrospinal fever" harbored in their nasopharynx organisms indistinguishable from the meningococci (8), a result confirming previous studies which showed that "meningococci are to be found in a considerable percentage of persons in whom no relation to cases of cerebrospinal meningitis is discoverable".…”

“…It is sometimes difficult in these studies to determine whether a high carrier rate was associated with actual overcrowding, or to what extent a high carrier rate was in itself interpreted as evidence of overcrowding. A sharp rise in the noncontact carrier rate "is a sure a storm signal of imminent danger of an outbreak as it is a sign of overcrowding or of dangerously deficient ventilation" (7). (The latter was sometimes invoked in instances of otherwise unsatisfactory evidence of ''overcrowdingg".…”

An epidemiological review of changes in meningococcal biology during the last 100 years

“…Carriage was highest among military populations. 59,65,75 Among civilian populations, carriage ranged from 4 to 18.8% although two-thirds of participants were less than 12 years old in the study where the lowest average carriage rate of 4% was reported. 37,57 It was reported that the presence of respiratory infections facilitates carriage but no evidence of association between respiratory infections and carriage was found in two studies.…”

Meningococcal carriage, alcohol consumption, and campus bar patronage in a serogroup C meningococcal disease outbreak

“…Crowding, cigarette smoke, and alcohol would seem the most prominent candidates. Elevated carriage and disease have been linked to shared living accomodations and possibly crowding in studies evaluating spread in households and dormitories (7,10,15,18,21). Crowding in a campus bar environment is of shorter duration but often at much higher density than that observed in households and dormitories.…”