Further preliminary reports on flies as carriers of infection.

Date:
1909
Catalogue details

Licence: In copyright

Credit: Further preliminary reports on flies as carriers of infection. Source: Wellcome Collection.

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    paper is coated. Bait for fly “ balloons ” should consist of a few grains of the coarsest brown sugar moistened with (but not dissolved in) a little stale beer. When desired, samples of the fly-papers and “ balloons ” recom- mended will be sent to Medical Officers of Health on application being made to the Medical Department of the Local Government Board. Collection and Enumeration of Flies. At regular intervals of 24, 48, or at most 72 hours, the papers and balloons are to be removed, fresh ones being substituted for them before the collector leaves the house. To kill the flies caught in the “ balloons ” the readiest method is to place the trap under a bell- glass together with a pledget of cotton-wool, on which has been sprinkled a few drops of chloroform. Or the trap may be dropped bodily into a bucket of boiling water, in which case it will be necessary afterwards to- turn out the dead flies on to a sheet of blotting paper to dry, before attempt at counting them is made. Before actual counting is commenced the flies should be sorted out, as far as possible, into different species, for which purpose the illustrations and descriptions contained in the pamphlet recently issued by the Medical Department will be found of service. The numbers of each species in the particular “ catch ” should then at once be entered in a book kept for the purpose. From the numbers thus obtained curves will subsequently be plotted, for comparison with curves representing incidence of deaths from epidemic enteritis, and also from enteric fever, in the event of this disease having been prevalent. Range of Flight. Much need exists for accurate information as to the distance, vertically as well as horizontally, to which flies can be traced from their breeding places ; or from some spot, for instance, at which specially marked flies are intentionally liberated. A paper by Mr. Jepson dealing with the marking of flies is appended. Bacteriology. In large towns especially, where expert assistance is likely to be available, observations on the bacteriology of flies, particularly of those caught in the enteric fever wards of hospitals or on premises invaded by epidemic enteritis, will obviously be of importance. “ Spot ” Maps. Maps will require to be prepared on which are shown the exact location of fly “ centres ” and observation “ stations.” On these pme maps shoidd be shown by means of dots the particular houses invaded by epidemic enteritis or enteric fever, respectively. 14009 A 2