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Cholera Vaccine and InternationalTravel

THE LANCET

IN 1971, cholera became once again a dominantglobal public-health problem. A major epidemicoccurred in India among the refugees from Bangla-desh, and outbreaks of cholera were reported fromforty-two countries. Fourteen countries in East andWest Africa, in North Africa, in the Arabian penin-sula, and in Europe experienced the disease for thefirst time. There were some 150,000 reported casesof the disease-three times as many as in 1970.1

Emergency assistance was provided through theWorld Health Organisation by a score of contributingcountries. Supplies of rehydration fluid, antibiotics,bacteriological media, diagnostic antisera, vaccine,and vaccination equipment were promptly dispatchedto the centres of distribution. Many lives were savedand in some areas the epidemics soon abated. Thenumber of reported cases of cholera increased in 1972to some 170,000, but this reflects improved epidemio-logical surveillance of the disease; about 100,000cases were notified in fourteen countries of Asia,and 70,000 cases in twenty-two countries of Africa,and 121 cases of imported infection were recorded inseveral European countries.2 2 However, while thegeographical spread of cholera is still very wide, thesize and severity of outbreaks has certainly decreased.The spread of this, the seventh, pandemic of cholerawas largely due to the El Tor biotype of Vibrio

cholerae, which causes many mild or symptomlessinfections.3 3 Greatly increased population mobilityby air, sea, rivers, and land, together with poorsanitary conditions in congested areas in developingcountries, are responsible for the new situation. 4

Since improvement of environmental conditions suchas proper sewage disposal and provision of safe

water-supplies demands time and is expensive, muchreliance has been placed on vaccination againstcholera, which was first introduced in 1884 byFERRAN (a pupil of PASTEUR) and used with somesuccess by HAFFKINE in 1892 in India.

Belief in the efficacy of vaccine to deal with anylarge-scale outbreak of cholera has been dispelled bytwo controlled field trials.5,6 In the Philippines,5monovalent Inaba and Ogawa parenteral vaccineswere given in an area where the causal organism isthe Ogawa serotype. The Inaba vaccine gave about

60% protection for 6 months, while the Ogawa1. The Work of W.H.O., 1971. Off. Rec. no. 197. World Health

Organisation, Geneva.2. Wkly epidem. Rec. 1972, no. 30.3. Cvjetanovic, B., Barua, D. Nature, 1972, 239, 137.4. Lapeyssonnie, L. Thesis. University of Montpellier, 1972.5. Azurin, J. C., et al. Bull. Wld Hlth Org. 1967, 37, 703.6. Mosley, W. H., Bart, K. J., Sommer, A. Int. J. Epidem. 1972,

1, 5.

vaccine gave some 70% protection for a similar

period. But the incidence of cholera in villagesprovided with simple sanitary facilities was reducedby about 70% in 3 years and cost-benefit analysis hasconfirmed that this is more permanent and econ-

omically more advantageous than mass vaccination.Lately, two investigations 7,8 in Bangladesh, carried

out by the Cholera Research Laboratory at Dacca,indicated that there was no appreciable difference inthe incidence of infection in two groups of contactsof cholera patients-one group being given a mono-valent Inaba vaccine and the other a placebo. Mass-vaccination programmes are of little value as a

public-health measure because the short duration ofprotection and the high cost of vaccination force theauthorities to postpone the campaign until clinicalcases become apparent; by then, intervention is toolate to stem the outbreak. In these circumstances,tetracycline is a more effective prophylactic agent.

Control of cholera depends on the establishmentand maintenance of a level of sanitation that will

prevent faecal/oral transmission of the pathogen.3 3A safe piped water-supply, good methods of sewagedisposal, improved housing conditions-all these arebetter long-term investments in health than any large-scale immunisation programmes with the existing,not very satisfactory, vaccines. Nevertheless, immun-isation reduces quite substantially the risk to indivi-duals and should be made available to those particu-larly exposed to the infection. Medical personneland travellers proceeding to countries where cholerais prevalent should be protected by vaccination. The

vaccine, while offering partial protection, does notprevent people from becoming carriers of thedisease. Surveillance and treatment are sufficient tocontain the infection if it is introduced. Manycountries, including the U.K., require travellers

coming from certain countries to produce validinternational certificates of vaccination againstcholera. The U.S. Public Health Service,9 havingrecognised the limited value of vaccination againstcholera, no longer requires a certificate of travellerscoming to the U.S.A. from cholera-infected areas.This stand has now been endorsed by the 26thWorld Health Assembly, which introduced a changein the International Health Regulation so that hence-forth vaccination against cholera shall not be requiredas a condition of admission of any individual travellerto a country The question of removing cholerafrom the list of diseases covered by the InternationalHealth Regulations was discussed, but the 1973World Health Assembly wisely decided that thiswould be inappropriate, since it might imply thatcholera is no longer a serious public-health problem.This is certainly not so, and the continuing menace

7. Sommer, A., Khan, M., Mosley, W. H. Lancet, June 2, 1973, p. 1230.8. Sommer, A., Mosley, W. H. ibid. p. 1232.9. Communicable Disease Center. Morbidity and Mortality. ACIP

Recommendations, 1972, no. 21.10. World Health Organisation. Press release WHA/18, May 23, 1973.

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of cholera should serve as a reminder that the

improvement of environmental health in this shrink-ing world is more important than every

HERNIOGRAPHY

INGUINAL hernia is one of the commonest reasonsfor admission of a child to hospital for surgical treat-ment, yet accurate diagnosis of this simple anomalyappears still to be extremely difficult. Gilbert and

Clatworthy,12 in 164 patients who were each examinedmore than once by an experienced pxdiatric surgeon,found the diagnosis was wrong in 400,’,. White, Haller,and Dorst 13 likewise found an error of 40% in theclinical diagnosis, even though each patient was

examined by three surgeons. What is worse, diagnosiswas equally fallible in children over the age of twoyears. Opinion is divided on how often a hernia whichdoes not give rise to symptoms or physical signs willbe present on the other side. Roew et aI. 14 came to theconclusion that 40% of 1900 patients they examinedhad an open hernial sac on the opposite side and thathalf of these subsequently had symptoms of herniation.It is not surprising, therefore, that a number of

surgeons have recommended exploration of the

opposite side even when symptoms are confined toone hernia, on the ground that this avoids readmissionof the child to hospital and a second anxsthetic andoperation. Obviously, half the operations will be

unnecessary; they are also more likely to be asso-ciated with damage to the testicular artery, veins, orvas, since absence of a hernia leads to more intensivedissection in the search for the hernial sac.

Various methods have been proposed to make pre-operative diagnosis of hernia more exact. One is to

try to pass a sound or bougie through the hernial sacon the side which is giving rise to symptoms into thehernia on the opposite side; another is injection ofradio-opaque medium into the peritoneal cavity,followed by X-ray examination of the patient in theupright position (herniography). The report ofDucharme et al.,15 in which radiological diagnosis waswrong only 3 times in 60 patients, has been followedby a number of others.13.ic-is Blau et al.l8 recommendinsertion under local analgesia of an 18-gauge arterialcatheter into the peritoneal cavity through a smallincision just below the umbilicus. They then injectup to 30 ml. of meglumine iothalamate in a 60%solution (which they believe causes less discomfortthan other solutions). Care is taken to reduce anyknown hernia and the patient is exercised for five

minutes, infants being gently shaken in the uprightposition. X-rays are then taken 5 minutes and 15

11. Department of Health and Social Security. Communicable DiseasesContracted Outside Great Britain. London, 1972.

12. Gilbert, M., Clatworthy, H. W. Am. J. Surg. 1959, 97, 255.13. White, J. J., Haller, J. A., Dorst, J. P. Surg. Clins N. Am. 1970

50, 823.14. Rowe, M. I., Copelson, L. W., Clatworthy, H. W. J. pediat. Surg

1969, 4, 102.15. Ducharme, J. C., Bertrand, R., Chacar, R. J. Can. Ass. Radiol

1967, 18, 448.16. White, J. J., Parks, L. C., Haller, J. A. Surgery, St. Louis, 1968

63, 991.17. Swischuk, L. E., Stacy, R. M. Radiology, 1971, 101, 139.18. Blau, J. S., Keating, T. M., Stockinger, F. S. Surgery Gynec

Obstet. 1973, 136, 401.

minutes after the injection. As well as carrying outthis procedure, Blau et al. operated on both sides

irrespective of whether or not a hernia had beendemonstrated radiologically. Operation confirmedthat they had made the diagnosis correctly in everyone of their 40 patients. The risk of perforatinga distended bladder is reduced by getting the patientto pass urine before the catheter is inserted. Allergicreactions to the contrast medium have not beenreported, but care should be taken not to perforatethe bowel when the catheter is pushed into the

peritoneal cavity.Herniography appears to be a reliable method of

diagnosing symptomless hernias in infants, and so farno serious complications have been reported. Thetechnique may be justified in situations where the error-rate is high, 12,13 but centres with lower rates of diag-nostic failure will probably be unwilling to adopt it-especially as a means of excluding bilateral hernia inthe four out of five patients who have symptoms ononly one side. It is unlikely to be adopted by surgeonswho do not feel compelled to explore both sidesroutinely when history and physical examinationsuggest hernia on only one side. Herniography ismost likely to appeal to surgeons who do not habituallydeal with children, in the hope that their occasionalforay into this area will be made more productive bymore reliable diagnosis. But these are just the circum-stances in which the technique is least likely to

commend itself to those who prefer to treat childrenin children’s hospitals. Herniography involves radio-logical examination of the pelvis and gonads in eithersex, and for this reason alone it seems an undesirable

practice-even in pxdiatric radiological departments,where radiation dosage is consistently and con-

scientiously controlled. In many adult radiologicaldepartments, control of the dosage and technique forX-raying children and babies compares poorly withthat in paediatric radiological departments, andundesirable exposure to radiation is a distinct hazard.

CR

IN part 11 of their inquiry into the riot-control agentCS the Himsworth Committee 19 spelled out a principlerelating to any decision to release chemical agents foruse in civil disturbances-namely, that medical andscientific research relevant to such a decision should be

published. This did not happen with CS. Will it

happen with the successor to CS ? The signs are notencouraging. Strictly speaking, the Himsworthprinciple is not yet relevant to CR, for no decision touse it in Northern Ireland or anywhere else in theUnited Kingdom has yet been taken. However, theMinistry of Defence now confirms that CR is in pro-duction 20 and the U.S. Army may shortly decide toadopt CR as its agent of choice. 21 Little enough wasknown about CS when it caught the attention of news-men and scientists alike in 1969, but even less is knownabout CR at a time when it could, on a minister’ssay-so, be used tomorrow.

19. Report of the Enquiry into the Medical and Toxicological Aspectsof CS: part II. Cmnd. 4775. H.M. Stationery Office, 1971.

20. Times, June 7.21. Jones, R. New Scientist, May 31, p. 546.