War Surgery and Medicine
Shortly after the start of the Second World War it was decided to X-ray the chests of all soldiers before they went overseas, but efficient equipment was lacking in certain areas, and there was a shortage of technicians, radiologists, and specialists in pulmonary page 589 tuberculosis. By the time arrangements had been made the First Echelon had sailed, and not many of the Second Echelon could be examined. (This point is important, as will be seen in the discussion on incidence.) Thereafter most members of the forces were X-rayed as part of their initial medical examination or else while they were in training camp. Later, chest X-rays were taken on discharge from the forces.
Mass radiography was introduced in order to eliminate the recruit likely to be useless and a burden to the service. It was a rapid and efficient method of detecting latent tuberculosis, and reduced the number requiring specialist examination. In spite of the strain under which they worked, the radiologists missed very few cases, although medical histories could not be made available to them. When microfilm came into use later in the war extra checks on large films were made in 5 per cent of cases.
Between two and three recruits per thousand were rejected on account of an active tuberculous lesion, and these were in men otherwise reported as fit after medical examinations. Many hundreds of cases reported on at enlistment as showing abnormalities relating to tubercular infection, but accepted as having no active disease, served through the war and never had any symptoms of the disease. The methods adopted were justified. Although 71 cases taken into the Army overseas with some evidence of old or latent infection were later diagnosed as suffering from active pulmonary tuberculosis, on the average they gave several years service and 25 were detected only at discharge. If a policy of doubt and fear had been adopted in all suspicious cases the services would have lost many recruits. Great care is required that unnecessary invalidism is not created by mass radiography.
All cases showing radiological abnormality were referred for boarding to specialists in disorders of the chest. Cases of active tuberculosis, however slight, were totally rejected; others with inactive lesions were in some instances graded for limited military duties in New Zealand.
The benefits of routine radiography have been amply emphasized by a survey of records of over 100,000 apparently normal recruits. It was found that the incidence of active pulmonary tuberculosis was 2.4 per 1000—a figure which compares favourably with that obtained from similar surveys in other countries. Reliance on clinical examination alone permitted detection of active tuberculosis in only 3.6 per cent, and suspicion of active tuberculosis in a further 3.2 per cent of the cases subsequently proved to be tuberculous. In other words, in 93.2 per cent clinical examination was negative, and only routine radiography raised the suspicion for subsequent page 590 confirmation by specialist boards. These figures speak for themselves, yet probably do not give an accurate assessment of the true incidence of detectable clinical signs. The conditions under which initial medical boards are of necessity conducted are not ideal for careful auscultation. In any case, the knowledge that a routine X-ray was to follow probably prompted and in part justified a relatively cursory examination of the chest by medical examiners working in adverse conditions. In the small group of cases detected or suspected clinically most had a bad family history, gross symptoms, or obvious physical signs; 33 per cent were Maoris.