A.—3

39

9. Infection with other Intestinal Parasites. In the course of examination of specimens for hookworm disease the ova of other intestinal parasites are incidentally discovered and noted. When hookworm-ova are found, the microscopist passes on to another specimen. We gave more attention to the specimen than this in the Cooks, and our records should be fairly accurate for those parasites whose eggs are floated by the Willis technique. Table 6 shows these other infections :—

Table 6. —Other Intestinal Parasites.

Tlie Trichuris trichiura; is found among all Melanesians and Polynesians, and this is lower than the infection-rate usually found among them. The Ascaris lumbricoides, however, does not seem to belong to these races, and is only found among them when introduced by other races. It seems evident to me from Table 6 that this worm has been introduced in comparatively recent times, as a glance shows that the infection has not yet reached a state of equilibrium throughout the Group. A compilation of the infection-rate by age and sex of the ascaris and trichuris infections shows that children get the infection and gradually lose it as they get older, this process being more marked in the case of the ascaris.

Table 7. —Infection with other Parasites, by Age and Sex.

10. Pig Worm-counts. We examined three pigs' guts and found that they contained forty worms. Among these were two ascarides, five trichurides, many Oesophagostomum dentation, and several which we did not recognize. They are being forwarded to Dr. B. H. Ransom, of the Bureau of Animal Industry, Washington, D.C., for examination. PART IV.—DISCUSSION AND CONCLUSIONS. On the whole, the Cook Islands have no grave public-health problems to face except the serious one of soil sanitation. Leprosy, which has been difficult to handle properly heretofore, should cease after a time if those at present infected are carefully weeded out and sent to Makogai. Yaws, on the whole, has been handled well. If present plans as outlined by the Medical Department are carried out, yaws will cease to exist except in a sporadic form as carried into the Group. Filariasis cannot be treated with our present knowledge ; and prophylasis —the suppression of the mosquito —is, with our present knowledge, probably out of range of the Cook Island Treasury. Intestinal parasites —hookworms and ascarides —could be eliminated as an economic factor, in all probability, by two thorough mass treatments separated by an interval of a year. Adequate instruction in the dangers of soil-pollution, and the installation of simple, inexpensive latrines, should prevent its return as an economic factor. This possibility would depend on the thoroughness of the instruction and the type of latrine installed, and its maintenance. This can never be done by the Medical Department alone. The hookworm work should carry with it instruction in simple sanitation, but the school system should make compulsory the adequate study of simple hygiene and publichealth problems in all the schools. Any other system of education in the tropics is incomplete. Because the Cooks have never experienced a great epidemic of typhoid is no reason for supposing that it cannot occur. There are said to be at present about thirty cases in the Avarua

Infected. Island. Examined. : Ascaris. Trichuris. Oxyuris. Per Cent. Per Cent. Per Cent. Rarotonga .. .. .. 532 135 25 213 40 2 2 Mangaia .. .. .. 89 10 11 14 15 2 13 Mauke 129 31 24 49 38 1 2 Mitiaro .. .. .. 53 20 37 21 38 Atiu .. .. • • 104 6 5 33 31 4 4 Aitutaki .. .. .. 96 12 12 13 13 1,003 214 21 343 34 9 1

Infected. Examined. — Asearis. Trichuria. Per Cent. Per Cent. Men .. .. .. . • 265 38 15 77 29 Boys .. .. .. ..292 76 26 110 37 Women 193 25 12 45 24 Girls .. .. •• ..253 75 29 111 43