Sessional_Paper_1918 — Page 78

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74

Summarizing the results of the positive cultures, we find that there are:---

Normal types (corresponding to Type II of the English

classification),

Para type (corresponding to Type 1 of the English clas-

sification),

11

Irregular normal type (Type IV ?),

Irregular para types (Type III ?),

Irregular (neither normal nor para) including those men-

tioned under "4" above,

Cultures impossible to agglutinate as no growth was

obtained,

Inagglutinable types,

Total,

1

2

7

32

Therefore, notwithstanding the fact that no cases have developed in the gaol, we find in the series investigated that 2461 per cent. harbour meningococcus-like orga- nisms in the nasopharynx.

An analysis of the types found show that three inmates yielded para of irregular para- meningococci, the types prevailing in the epidemic in the Colony. Yet the normal or regular types of meningococci, which are capable of developing the disease, were present in 11 of the prisoners. The significance of the predominant normal types in the healthy carriers and the presence of the other irregular types is still under investigation. The types among the cultures of contacts taken by Drs. Macfarlane and Earle were not deter- mined so that no comparisons can be made.

The age of the inmate apparently has no bearing on the carriage of the meningococcus.

The length of time of detention in the gaol previous to the taking of the culture is summarized as follows:-

Up to 1 month.

From 1 to 3 months.

From 3 to 6 months.

Negatives Positives...

32

9

31

18

10

From 6 to 12 months.

13

After 1 year.

I

12

0

It will be noted that most of the inmates showing positive cultures have been con- fined, up to 3 months. The epidemic was 5 months in its course when the cultures were taken. The three inmates who carried the same type of meningococci which prevails in the epidemic entered the gaol, 11 days, 29 days and 36 days previous to the culture. In other words, it appears that the old prisoners were less apt to be infected than the younger (with regard to the time of confinement).

With reference to the degree of infection, it will be noted that most of these carriers harboured only few or occasional organisms. However, in four carriers they were nume- rous (2 plus) and in two the meningococcus was the predominating organism (3 plus). One of these two carried the same type found in the patients (irregular para). while the other, the irregular type.

The former (Prison No. 5662) may be regarded as a "dangerous carrier". I shall explain this term later on.

Finally in several instances, more than one colony of the same plate culture was examined for type. The results confirm the already established fact that usually all the meningococci in the same nasopharynx are of the same type.