War Surgery and Medicine
In 1949 Dr D. Macdonald Wilson made a survey of pulmonary tuberculosis among New Zealand service personnel, embracing all the cases that had occurred in the ten-year period 1939–49 in a military population of 200,000 medically examined and passed fit for service, of whom about 134,000 served outside New Zealand. In the main this was a specially selected population, but, on the other hand, chest X-rays at discharge from the services, plus pensions applications later, resulted in nearly all those developing tuberculosis being brought within the compass of the review. Up to 31 December 1949, 1412 cases had applied for pension, while there had been 8 deaths on service overseas and 30 among servicemen in New Zealand. Included were 193 cases of pleurisy with effusion. Approximately 37.5 per cent of the cases took ill on service, 42.5 per cent were diagnosed by routine X-ray (usually at discharge), and 20 per cent became ill after discharge from service.
It was found that whereas the Army and Air Force produced numbers roughly corresponding to their relative strengths, the Navy had almost double the number of cases on a comparative basis. This emphasized the fact that exposure to infection rather than the physical hardships of a campaign is the greater cause of tuberculosis in the services. The naval authorities early became aware of this, and routine surveys by X-ray were carried out as frequently as possible, thus enabling many unsuspected cases of active tuberculosis to be diagnosed.
The importance of X-ray at enlistment was emphasized by the higher incidence among those army personnel of the first two echelons who were not X-rayed in 1939–40. The members of the Maori Battalion fortunately were nearly all X-rayed, so removing most of the potential sources of infection (16 per cent were rejected for chest conditions), and the Maoris in the services had an incidence of less than double the incidence for the whole group (13.5 against 7.4 per 1000 over the ten years), whereas in the civil population the Maori rate is nearly five times that of Europeans. By comparison page 592 with the annual civilian Maori rate of 23.5 per 1000 the rate of 13.5 per 1000 for a decade in Maoris who served overseas shows a marked reduction. (It has to be noted that on a comparative basis living conditions were much the same for Maoris and Europeans in the forces, but this is not so in civil life.)
In prisoners of war the incidence was fairly high—over 17 per 1000 over the period, but 84 of the 155 army cases had not been X-rayed on enlistment. Most of the prisoners of war were taken in the early campaigns and had entered the Army in 1939 and 1940 before the X-ray examinations were properly organised. Irrespective of prisoner-of-war privations, this group would have produced a higher incidence than the average. Of the total of 729 cases in the Army overseas, 222 were not X-rayed before going overseas. The First and Second Echelons, with 193 cases, produced an incidence of 14.3 per 1000.
The annual incidence of new civilian cases in 1948 (the lowest on record at that date) was European 0.77 and Maori 3.6 per 1000. The average annual incidence in returned service personnel for the years 1945 to 1949 was European 0.95 and Maori 1.73 per 1000. It has to be noted that the service figures were swollen by the large number of cases brought to light by X-rays taken on discharge after return from overseas in 1945 and 1946.