HEALTH NOTES.

Otago Witness, Issue 3803, 1 February 1927, Page 9

HEALTH NOTES.

CARRIERS OF DISEASE. THEIR CONTROL AND RECOGNITION. Contributed by the Department of Health. The origin of epidemics of infectious disease has long been a mystery, and it is still largely a matter of conjecture how or why they come to an end. With regard to the latter, several factors may co-operate, such as a gradual diminution and ultimate loss of virulence of the infecting agent, the survival of the fittest among the population attacked, and the production of an acquired immunity by these' individuals. With regard to the former problems, however, as to how cases of infectious disease—whether sporadic or epidemic—start, nothing definite was known until it was discovered that persons who had previously suffered from certain infectious diseases, notably enteric fever, were the cause of outbreaks of the disease among people with whom they come in contact. Such individuals are known as “ carriers.” A carrier may be defined as a person who in some part of his body carries the germs of an infectious disease without himself exhibiting symptoms of the disease.

This “carrier state,” as it is called, may develop as a consequence of having had. the special disease, or it may develop in one who has never had the disease—that is, we may have “ convalescent carriers ” or “ contact carriers.” Also carriers may be either temporary or chroic—that is, they may harbour the germs either for only a short time or for a much longer time, . stretching into months, years, or even, in some cases, the rest of a lifetime. Now it will be easily understood that from a public health point of view the recognition of these “ carriers ” is most important, and even when recognised the problem of dealing with them is bristling with difficulties.

Having recognised the carrier and identified the particular bacteria that he or she is harbouring, it has next to be proved that the germs present are capable of infecting another person. Because not all germs are what we term pathogenic—that is, are capable of causing disease. For instance, it is well known that a person may harbour in his throat germs that, on microscopical examination, are identical in all respects with diphtheria bacilli and yet these may be quite a-virulent or .quite incapable of causing diphtheria either in himself or anyone else. It is. admitted among bacteriologists that bacteria that are avirulent never become virulent, but are always quite incapable of causing any infection, so that here at least as far as diphtheria carriers are concerned we have another problem to solve. We must not only identify the carrier, but also must prove whether he is a dangerous or a harmless carrier. This problem, as far as we at present know, arises only in the case of diphtheria carriers, and; fortunately, we have in this case means at our disposal to help us in arriving at a definite conclusion. From the public health aspect in this Dominion the following diseases present their “carrier” problems:—(l) Diphtheria; (2) enteric infections (typhoid and paratyphoid > ( 3 ) cerebro-spinal meningitis; (4) strepto-coccal infections. DIPHTHERIA.

This question of the “carrier” in this disease is in this country the most important of them all. The carrier state n * a s’ develop here as a result of an attack of diphtheria or merely as the result of coming into contact with a clinical case of diphtheria or another carrier. The carrier state may persist for some months, but is seldom or never permanent. It I s ’ j- s J las b ® en P° inted out, most important to differentiate between those carriers who convey virulent germs and those who harbour only a-virulent germs Briefly, the method of doing this consists in isolatipg the diphtheria bacilli and seeing if they will give a reaction in an animal like a guinea-pig, which has first been protected by a dose of diphtheria antitoxin. Another way is to subject the carrier to the ‘ Schick Test,” which is a test that has been devised with the object of ascertaining whether a person is susceptible or not—susceptible to diphtheria infection. . If a person gives what we call a negative Schick reaction he is considered to be nearly, but not absolutely, immune to diphtheria. If he gives a “positive” Schick reaction, he is considered to be susceptible to diphtheria. Now, the inference is, therefore, that if we isolate diphtheria bacilli from a person who is Schick positive, either he will develop diphtheria or his bacilli are a-virulent. But if the person is Schick negative then the bacilli isolated may or may not be a-virulent and must be tested further. The throat and the nose are the usual Sl i t i ? s ? or , carr yi n g diphtheria bacilli, although they have occasionally been isolated from the ear and from wounds. The question of isolation of diphtheria cartiers is one in which no specific statement can be made, the decision in each case is one resting with the individual medical officer of health. ENTERIC.CARRIERS. " These are persons who harbour the germs of tj’phoid or the paratyphoid forms. These “carriers” may also be of the two kinds, temporary or permanent. The temporary carriers are usually persons who are convalescing from the disease, and they usually soon clGar up. Occasionally, however, the condition may become more permanent, and these unfortunate individuals may “carry” these bacteria for years, or ,*pY en * or °f their life-time, they are not usually, however, continuous carriers, that is, there may be intervals of from several weeks up to several months during which it is impossible to recover the specific organism from their excretions. These “carriers” are usually of the intestinal type, that is, the bacteria are usually recovered from contents of the bowel. Occasionally we find a

“urinary” carrier who excretes the bacteria in the urine. The intestinal carrier state may also arise in one who has never had the disease. The identification of these enteric carriers is a problem presenting much greater difficulties than in the case of the diphtheria carriers. The bacteriological examination and test required are more elaborate and time consuming. They also differ .in one other respect from diphtheria carriers, in that none of them as far as we know are “a virulent,” but all are capable of infecting other people. Most of them are women, and many present symphoms of gastro-intes-.tmal disease such as pain in the region of the gall bladder, indigestion, diarrhoea, etc. .As to the treatment of these “enteric carriers,” a cure is practically impossible; they may remain apparently clear of the organism for months and the carrier state may again be in evidence. Fortunately, the observance of a few simple precautions is usually. sufficient to protect other people. Fhe chief of these precautions are:—(a) Prompt and efficient disinfection and disposal of the excretions; (b) cleanliness of the hands after having had a bowel movement; (c) abstinence from having anything to do with preparation or serving of food for other people. Usually when the position is explained to the unfortunate carriers, their complete co-operation is secured, and thus the possibility of their being a menace to their fellow creatures is removed. Obviously isolation of these people would be impossible unless isolation was observed for the remainder of their lifetime. The chief storehouse for these germs is usually the gall bladder, and some then have been cured by having that organ removed; but even then no guarantee can be given. Many typhoid epidemics in New Zealand as well as in other parts of the world have been traced to carriers of typhoid germs. CEREBRO-SPINAL MENINGITIS.

It can be safely .said that in no other disease is the continuance of infection from season to season or from epidemic so dependent on carriers as in cerebro-spinal meningitis. The carrier is of importance not only in the spread of epidemics, but also in the occurrence of sporadic or occasional cases. The cause of the disease is a minute organism called the meningococcus It is an extremely frail organism and when removed from the body it very soon dies. The organism usually inhabits the region behind the nose, called the nasopharynx. Here again the “carrier” state may arise as a consequence of having had the disease more usually, however, in this diease the carrier state arises as the result of having been in contact with an actual case of cerebro-spinal meningitis or with another carrier. The carrier state may last from only a week or two up to several months. It is estimated that in an ordinary healthy communty there are 2 per cent, of meningococcus carriers. How then is it that more cases of tm s ailment do not occur? Simply because it has been discovered that before an outbreak of this disease can occur there must be a much greater concentration of carriers, and there must be a certain continuous period of contact with a carrier e.ore sufficient infection is' received to oveicome our natural or acquired resistance.

j-X le I . l^e ™ I ® ea . t,o, ‘ of these carriers is not difficult. The chief essential is to make the bacteriological examinaton as promptly as possible after the material has been taken from the naso-pharynx. The naso-pharynx lw a l" ab^ ed a s P ee 'ally epnstructed swab and a suitable material is innoculated on the spot, or if a laboratory i s handy, the suspected carrier is sent there to have his examination made. Cerebro-spinal meningitis is most likely to occur where we get great concentration oi people as in army camps, etc. Another peculiarity of this disease is that it is very rare for a carrier to develop cerebro-spinal meningitis. The carriers are treated usually by various antiseptic douches, inhalations, or paints. The usual procedure is to consider a carrier as free if consecutive swabs suit™ 48' bour intervals give negative reSTREPTOCOCCAL CARRIERS. Streptococci form a large group of. microorganisms or bacteria, possessing certain features in common, but still capable of being differentiated into certain fairly wellg^ ups or “strains” as they are called. They are widely distributed in nature and it is considered by competent authorities a large percentage of people carries streptococci in the throat in and about the tonsils. Many disease conditions are due to infection by streptococci and many of the lung conditions following infection of influenza in the late epidemic were due to a secondary infection of streptococci. Similarly some of the lung complications following measles are due to infection of streptococci from the patient’s own throat. It is now known that scarlet fever is caused by a specific streptococcus. Other conditions due to invasion of these organisms are erysipelas, puerperal fever, septicaemia, or blood poisoning, etc. Unfortunately our knowledge of the streptococci is still very incomplete. We can identify the streptococcus, but we cannot accurately differentiate between the various strains Neither can we determine accurately the virulence” or power of invasion of the various strains. However, rapid strides in our knowledge are daily being made, and it is not too much to hope that in the near future we shall be able to identify the harmful carrier of streptococci as completely as we can that of diphtheria. Other diseas.ee. present their carrier problems, but in this country their public health importance is not great.

In an editorial the New Zealand Accountant says that in the course of its business it has recently scanned about 300 letters from youths, applying for positions, and it found that in letters from lads who had been given the privilege of secondary education the spelling and punctuation were abominable, and from the point of view of the commercial community, one wonders whether we are getting adequate value for the huge.sum of money that is expended annually in New Zealand on higher education. When walking along Ocean beach, at the foot, of Karori Hills at Raglan, a party of visitors discovered the skeleton of a man which had been exposed by the drifting sand. The party buried the skeleton. During storms human skeletons are frequent.lv uncovered at this spot. The skeletons are regarded. as those of Natives who died or were buried there many years ago. Greenstone meres and other Maori curios have also been found among the skeletons.