— 26

This latter would seem to indicate that even in the heavy malarial year of 1027 when anti-malarial measures in the irrigated area had to a considerable extent broken down owing to the tenants being incapacitated for the proper

baling out of the irrigation channels the malaria rate outside the irrigated area was higher than that in the area. The indication is interesting, but needs further

confirmation. It is hoped during the ensuing year to carry out spleen counts to elucidate this and other points.

Additional measures taken to diminish the malarial incidence. Apart from the routine measures ordinarily enforced, i.e. the complete drying off of the small distributary canals between waterings, the oiling of seepage or other accumula¬ tions of water, the early treatment of all infected cases at dispensaries and the adequate mosquito protection of all European houses the following additional measures were taken :—

(i) The banks of all canals which seeped badly were heavily strengthened with earth.

(ii) Mosquito nets were issued to all tenants and their dependents. (iii) Insistent propaganda among Europeans as to the importance of the routine killing of all mosquitoes lurking in the house.

(iv) A medical inspector was seconded for the special study of mosquito conditions and malaria in the irrigated area, under the direction of the Director,

Wellcome Tropical Researcu Laboratories,

As regards (i). This strengthening of the banks was only effective in preventing seepage in 50% of the cases. The determining factor in seepage from the canals appears to be the high storage level of water which has to be maintained to obviate night watering. It is possible that a lowering of the storage level might be obtained :—

(a) By stricter water control and thus having to store less water. (b) By cutting out certain high areas so as to obviate the high storage level needed to irrigate these small areas of higher land.

In the canalisation of new areas regulators are being placed at more frequent intervals to diminish the height of the storage level that has to be

maintained.

Northern Provinces.

Small epidemics of malaria occurred in Dongola and Haifa Provinces in April and May as a result of the falling Nile leaving pools over wide areas of river bank. They were dealt with by routine measures.

Southern Provinces.

Progress is being made in improving the mosquito protection afforded to all officials serving in the southern stations.

Efforts are being made to popularise the use of the mosquito net among the natives living in their natural conditions and some progress is noticeable.

MALTA FEVER.

Twelve cases of this disease were reported, as against sixteen last year. The cases were distributed as follows

Omdurman . . 2 Port Sudan. . . . 1 Merowe . . . . 2 El-Dueim . . . . . . I

Kassala . . . . 6

(of whom one came from Kassala) (one fatal) (one fatal)