A.—3

38

In the Cooks it was exceedingly difficult. To rush on to on island, talk of a strange new disease, subject people to tests during which they must suffer confinement for forty-eight hours, the total length of the visit being three or four days, requires persuasive powers. Our visit was the most important affair of years on some islands, and each one who consented to tests was robbed of much of the pleasureable excitement of our visit. On Rarotonga we had planned to do more treatments in the gaol, but a hurricane in which we were unpleasantly involved used up a week of our time, and we returned to Rarotonga too late to make these counts. However, we made in all seven counts, on which we can depend absolutely. Our list of counts follows, with the island of residence. All subjects were male. All hookworms recovered were necators.

Table 5. —Worm-counts, Cook Islands.

The first seven of these counts were complete counts. The subjects were given 36 minims of a one-to-two mixture of chenopodium-tetrachloride mixture in a dose of saturated magnesium-sulphate solution, and their stools counted for forty-eight hours. Later they were given 45 minims of oil of chenopodium, and their stools counted for forty-eight hours, and all were found to have been cured by the first treatment. Probably the count may not show true total worm-count, as worms frequently pass on the third day; but it is relatively accurate, as the third-day count is usually small. These first seven complete counts total 392 worms —an average of fifty-seven worms per head. These subjects were not selected : they comprised all the males in the hospital and in the gaol at the time of the counts. The other subjects received 4 minims to the year of age of a one-to-three mixture of chenopodium-tetrachloride mixture, with an adult dose of 45 minims. Cook-Islanders, as with the Polynesian people in general, do not have so many worms per head, even living under the same climatic conditions as the Melanesians or the East Indians, probably because of their more cleanly habits of life. The remainder of our counts —from No. 8 to No. 23, inclusive —are not complete, nor a true index of the hookworm infection.' When mass treatments are given through the Group by a Medical Officer more counts should be made, so that an accurate record will be had of infective rates. Also, we did not visit the Northern Cooks, and we know nothing of the infection-rates there. Dr. J. P. Donald received an exact training in our methods of examination and worm-count while we were in Rarotonga. Clinically, Aitutaki and Mangaia are the heaviest-infected islands in the Southern Cooks. I believe that a rate of infection such as exists in the Cook Islands—-over 70 per cent.— especially when associated with the clinical manifestations noted, makes mass treatments of all the population imperative. Treatments with carbon-tetrachloride, or this in combination with oil of chenopodium, are cheap, efficient, and safe, and should produce striking results in the upbuilding of the population.

Hookworms recovered. Island. No. Age. i ; Forty-eight . Hours j Asoarls - Rarotonga .. .. .. .. 1 13 11 13 Aitutaki .. .. .. .. 2 Adult 168 1 Rarotonga .. .. .. .. 3 „ 25 1 4 „ 23 1 .. 5 „ 91 6 „ 49 7 „ 25 8 „ 7 Mauke .. .. .. .. .. 9 „ 94 ] „ .. .. .. .. .. 10 6 8 5 „ 11 15 11 5 , .. .. .. 12 ! Adult 8 Rarotonga .. .. .. .. 13 13 2 14 10 2 38 15 11 6 16 11 2 2 17 17 12 Pukapuka .. .. .. .. 18 16 12 1 Rarotonga .. .. .. .. 19 8 12 5 Atiu .. .. .. .. .. 20 12 2 „ .. .. .. .. 21 13 4 „ .. .. .. .. 22 20 5 ,, .. .. .. .. 23 30 37 616 73