RESULTS
A large amount of material was collected which is being studied in the laboratories. The blood specimens from human beings, domestic and wild animals and birds offer opportunity for a very comprehensive epidemiological and epizootiological survey. A start on the testing of these specimens against certain viruses has been made with results which are highly promising. It is apparent that human beings and certain of the domestic animals are very frequently attacked by certain viruses in Tongaland and that the distribution is not uniform throughout the area. lnfection seems to be most prevalent in the region of the rivers and pans and least prevalent on the Lebombo Mountains.
Seventeen virus strains representing six different types, three of these apparently hitherto unknown, were isolated during the expedition. A species of mosquito not hitherto suspect was incriminated as an important host and vector of virus. These and other findings are the subjects of the succeeding papers of this series.
The frequency with which various viruses attack human beings and domestic animals in Tongaland is a priority problem for this group of workers. The interest attaching to the region owing to the consideration being given to plans for a new maritime centre there and for the establishment of a comprehensive irrigated agricultural project reudered these observations timely.