H.—3l

The known incidence rates at 31st December, 1944, in two groups of certain tuberculosis control areas with predominanting European or Maori populations are compared with New Zealand average incidence rates as follows :—

It is to be noted that Wellington Metropolitan Area has the highest European incidence rate, and it is also found to have the highest European death-rate, 6-7 per 10,000. The Maori Factor as a Cause of High Incidence Kates The marked differences in particular areas of tuberculosis incidence rates is undoubtedly due to their higher Maori population. With the far too common deficiencies in his housing and the inability to control infection, the Maori " carrier " easily infects the immediate members of his family. With the Maori mode of life the resistance of the family to infection is low. Disease quickly supervenes in the younger members and rapidly progresses to a fatal termination . The behaviour of these " carriers " is the main factor in producing a pool of active tuberculous infection that persists in a community. It is believed that the Maori, given good home conditions and sufficient health education, has no less a resistance to infection than Europeans. Urbanization Factors It is found that European incidence is higher in the main towns than in the country areas. The majority of cases come from conditions where poor housing, overcrowding, and malnutrition exist in any marked degree. Climatic Factors Within New Zealand it is believed that climate plays little, if any, part in causing a high incidence and also plays no part in regard to the success of treatment and control. In this connection the low incidence rate, 3-25/1,000, and a low death-rate, 4-3/10,000, in the southern half of the South Island compares favourably with the comparable incidence rate of 4-08/1,000 and a death-rate of 4-86/10,000 for the Auckland Metropolitan Area. The success of treatment depends more upon the availability of accommodation for giving instruction in preventive measures, medical and surgical treatment, good housing, and graded sheltered employment for the recovering " quiescent " or " disease arrested " case than upon any virtues of a good climate alone. Our methods in dealing with tuberculosis patients are based on the following ideals (1) To find every case. (2) To classify every case into those that are (a) active spreaders of infection ; (b) inactive cases. (3) To segregate and control the active cases in hospitals and sanatoria or in their homes and, where possible, at their place of work. (4) To teach individual patients how to prevent the spread of their infection to others. (5) To review at constant intervals all inactive cases at a hospital tuberculosis clinic to ascertain if a relapse of activity has occurred. (6) To attempt to rehabilitate the quiescent or arrested case into a graded and suitable form of employment. (1) The finding of cases is by— (а) Notification by doctors of all cases suspected or found to have tuberculous disease and by reviewing the family or working contacts of these cases. Notification by general practitioners and hospital medical officers has improved. (On receipt of a notification of a case, District Health Nurses visit the patient in his home and endeavour to trace the hidden source of the infection, and attempt to find amongst the " contacts " of the patient any one who has contracted the disease by having them brought to the nearest chest clinic for diagnosis. Members of the patient's family are the first people surveyed. "Contacts" at the patient's place of work, if considered desirable, are also surveyed.) (б) X-ray Surveys of Selected Groups of People. —This work is being performed by hospital radiologists, but deficiencies in the numbers of trained x-ray technicians and the difficulty in obtaining x-ray equipment precludes the introduction of mass surveys of the population for some time to come. As an instance of this difficulty, the Taranaki mobile x-ray unit, which was ordered over three years ago, has not yet come to hand,

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I ~~ • : European Inciden®® Maori Incidence Area. Rate per Rate per 1,000 Population. 1,000 Population. (a) Predominating European-populated areasWellington Metropolitan .. .. .. .. 5'84 44-3 Auckland Metropolitan .. .. .. .. 4-08 30-45 Northern, half, South Island .. .. .. 3-73 25-81 South half, South Island .. .. .. .. 3-25 24-7 (b) High Maori-populated areas — North Auckland . . .. .. .. .. 1-47 10-43 South Auckland and Bay of Plenty .. .. 2-3 15-43 East coast, North Island .. .. .. 2-8 22-22 West coast, North Island.. .. .. .. 3-87 59-58* New Zealand average incidence rates (December, 1944) (1943 3-47 (3-20) 24-36 (19-60) figures in parentheses) * The intensification of tuberculosis control in the western area is largely responsible for the high figure quoted in the Maori incidence rate. It indicates the likely Maori incidence that may be obtained when case finding in the other areas is up to the same standard as pertains in the western area.