388 THE BLOOD ALCOHOL TEST

they may have a selective action on the M. leprce.Unfortunately early hopes have not been fullyjustified. G. R. Rao in India reported 4 that the dyeshad no appreciable effect either on the course of thedisease or on the causative organism. R. G. Cochranefound 5 that intradermal injections of brilliant greenhad little effect on the bacilli in the lesion, althoughthere was some flattening of infiltrations and nodules.French clinicians in Indo-China have recently beengiving 1 per cent. methylene-blue in double distilledwater intravenously in doses as large as 20 c.cm.,and regard this drug as having a specific action inleprosy. 6 Unpleasant reactions were avoided byextreme attention to purity and sterility. While theresults are encouraging, it must not be forgotten thatso many remedies in leprosy have only been effectivein their inventors’ hands. One difficulty in assessingtreatment is that many of the lepra bacilli found inthe body are already dead ; no drug would be effica-cious unless it actually caused their disintegration.On the other hand, there is evidence that M. leprcewill live for some years under laboratory conditionsin biopsied material without apparent change andremaining acid-fast. The next step should be anendeavour to find out whether injections of methylene-blue combined with hydnocarpus preparations are

more efficacious than other lines of treatment. Theclaim that this treatment will rapidly render opencases non-infectious will be looked upon with caution,for, in the general experience of leprosy workers, themore dramatic the improvement the less permanentthe results.

VIRUS CARRIERS

IN the control of epidemic disease of bacterial’ origin, such as cholera, diphtheria, enterica, and

cerebro-spinal fever, the identification of " carriers "

has proved of help and it is pertinent to inquirewhether virus infections may spread in a similar way.To what extent true carriers of poliomyelitis andencephalitis exist it is not yet possible to say, as

although their virus has been isolated, no simplelaboratory test for their detection is available. Itwould seem probable, however, that the most commontransmitter of infection is not a true carrier but a

person suffering from an unrecognised attack. Thetrue nature of such an attack may be suspectedwhen a mild febrile illness occurs in the midst of an

epidemic outbreak, but as it does not present anycharacteristic clinical features or provide any reactioncapable of laboratory investigation, such suspicionmay or may not be correct. In the absence of an

epidemic such an attack is not only unrecognised butunrecognisable. It seems that in some virus infectionsthere may be persons affected, and therefore possiblesources of spread, in whom the initial infection

produces no symptoms at all. This is certainly trueas regards encephalitis of Economo type. As theresult of the great epidemic of 1924 a number of

young people in this country are suffering from typicalpost-encephalitic phenomena of various kinds inwhom after the fullest inquiry no history can beobtained of a single day’s illness, or of any sign orsymptom which could be construed as the initialinfection. Such " occult " infections in epidemicencephalitis, which form quite a distinct group fromthe unrecognised or the abortive attacks, may proveas serious in their after-effects as a full-blown primaryattack. There are no late manifestations after polio-

4 Leprosy Rev., 1935, vi., 4.5 Internat. Jour. of Leprosy, 1933, i., 495.

6 Freville, L. H. F. : Bull. de la soc. méd.-chir. de l’indochiue,1934, xii., 615.

myelitis comparable to those following encephalitisof Economo type and similar retrospective deductionsare not possible ; but there are other grounds forthinking that in poliomyelitis also cases do occur whichmerit the term occult. Levaditi 1 gives his reasonsfor thinking that this type of poliomyelitis is importantin spreading the disease. Virus recovered from rhino-

pharyngeal and gastro-intestinal sites may be theonly evidence of attacks which are not merelyabortive but " tota,lement inapparentes." Such a viewis supported not only by the wide divergence betweenthe small percentage of paralytic cases in the courseof one epidemic, but also by the apparent immunityof almost the whole population in the affected area.Experimentally the virus has been obtained not

only from the throat but also from the intestinalcontents of those affected. Monkeys can be infectednot only by the nasopharynx but by introducingthe virus into the stomach, and even into a loop ofintestine. It is possible that the primary site ofhuman infection may be either rhino-pharyngealor gastro-intestinal ; a sore-throat or a gastricdisturbance may be its only signs of infection.

THE BLOOD ALCOHOL TEST

ESTIMATION of the alcohol content of the bloodhas been suggested as a means of establishing theextent to which a person is under the influence ofdrink. Reliable evidence on this point would oftenhave judicial value. Apart from the question ofwhether a suspected motorist is unfit to drive byreason of drink, it would assist justice to know theextent to which an injured pedestrian was himselfdrunk. Inebriation is in some circumstances a defence

against a criminal charge, and there are severalmethods, notably that of Widmark, of accuratelyestimating the concentration of alcohol in the blood.But even when this figure is known its practicalvalue is questioned. Dr. Ernst Silberstern hassatisfied himself 2 from experience as chief policesurgeon in Vienna that the quantity of alcohol inthe blood does not correspond with the conditionof the drinker. Many factors modify the effect ofalcohol, e.g., the form of drink, the relation to food,the stimulants that have been taken after thealcohol, accessory factors such as tobacco, carbonmonoxide, climate, and psychological constitution.The capacity of the person for doing a particular act,or the degree of his responsibility for his acts, is, hethinks, more likely to be estimated correctly by anexperienced clinician. Subject to these limitationshowever Dr. Silberstern finds that the blood alcoholtest has definite uses. A negative result may provethat the subject has taken no drink at all-a findingof importance in certain motor cases. It may alsoserve to fill up gaps in the clinical evidence, and toamplify the clinical findings and explain theirrelationship to the general condition. When it isnot possible to make a clinical examination at once,an immediate sample of blood may have a peculiarvalue. Since in this country the sample can onlybe taken with consent, the test may take long tocome into general use. Nevertheless there must becases in which a solicitor or a medical man acting onbehalf of an accused motorist should suggest an

immediate blood test. If it were negative or theamount of alcohol very small the result would be astrong point in his favour. If the finding wereunfavourable, the advisers of the accused would not

1 Levaditi, J.: Caractère inapparent de la poliomyeliteépidémique, Paris Méd., Jan. 12th, 1935.

2 Wien. klin. Woch., 1934, xlvii., 1518.