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The theory of amoebic surveys

Published online by Cambridge University Press:  15 May 2009

H. O. Lancaster
H. O. Lancaster
Affiliation:
School of Public Health and Tropical Medicine, Sydney, Australia
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(i) The theory of amoebic surveys and of related types of pathological surveys is discussed.

(ii) An inequality is derived,

where X is the total number of carriers and X1, X2 are the new carriers found at the first and second examinations.

(iii) Demonstrability is defined and several theoretical distributions of it are considered.

(iv) Demonstrability is shown not to be a constant in the populations considered.

(v) The danger of extrapolation is noted.

(vi) Life-table methods are introduced to treat some well-known published series.

(vii) A criterion for the adequacy of any estimate of the total carrier rate is given. The mean demonstrability of the outstanding carriers after successive examinations must form a decreasing series.

(viii) This criterion usually shows that the method of estimating the carrier rate for Entamoeba histolytica as three times the proportion of positives at a single examination, or as the total number of positives picked up in six examinations, both give too low a carrier rate.

(ix) It is suggested that the investigation of the ‘carrier’ rate may in certain cases be merely a measure of ‘demonstrability’.

(x) Possible future lines of investigation of the problem are noted.

Type
Research Article
Information
Journal of Hygiene , Volume 48 , Issue 3 , September 1950 , pp. 257 - 276
Copyright
Copyright © Cambridge University Press 1950

References

REFERENCES

Andrews, J. (1934). The diagnosis of intestinal protozoa from purged and normally passed stools. J. Parasit. 20, 252.CrossRefGoogle Scholar
Boeck, W. C. & Stiles, C. W. (1923). Studies on various intestinal parasites (especially amoebae) of man. Hygienic Laboratory Bull. U.S. Treasury Dep. No. 133.Google Scholar
Carter, H. F., Mackinnon, D. L., Matthews, J. R., Smith, A. & Malins., (1917). Proto zoological investigation of cases of dysentery conducted at the Liverpool School of Tropical Medicine (Second Report). Ann. trop. Med. Parasit. 11, 27.CrossRefGoogle Scholar
Dobell, C. (1917). Amoebic dysentery and the protozoological investigation of cases and carriers. Spec. Rep. Ser. med. Res. Comm., Lond., no. 4. FairfieldGoogle Scholar
Fairfield Smith, H. (1946). Appendix to Marsden (1946).CrossRefGoogle Scholar
Gini, C. (1924). Prime ricerche sulla ‘fecondabilità’ della donna. Atti Ist. veneto, 83, 315.Google Scholar
Mccoy, G. (1936). Epidemic amebic dysentery. The Chicago outbreak of 1933. Nat. Inst. Health Bull. U.S. Treasury Dep. No 166.Google Scholar
Marsden, A. T. H. (1946). The detection of the cysts of Entamoeba histolytica in the faeces by microscopic examination. Med. J. Aust. 33(1), 915.CrossRefGoogle Scholar
Porter, A. (1916). An enumerative study of the cysts of Giardia (lamblia) intestinalis in human dysenteric faeces. Lancet, 1, 1166.CrossRefGoogle Scholar
Sawitz, W. G. & Faust, E. C. (1942). The probability of detecting intestinal protozoa by successive stool examinations. Amer. J. trop. Med. 22, 130.Google Scholar
Sawitz, W. & Karpinos, B. D. (1942). Statistical problems involved in the application of the N.I.H. swab for the diagnosis of oxyuriasis. Amer. J. Hyg. 35, 15.Google Scholar
Svensson, R. (with the co-operation of Linders, F. J.). (1934). The chances of detecting infections with intestinal protozoa. Acta med. scand. 81, 267.CrossRefGoogle Scholar