Plague Conditions in a Rural Endemic Area of Kenya (Keruguya District, Kikuyu Province)

Extract

1. In the introduction, the characteristics of the people are given from the observations of administrative and medical officers well acquainted with the area, fertility of the land and ample rainfall being the main theme of each observation.

2. The topography, climate and local conditions are given, including notes on crop production, habitations, clothing, domestic animals, origin of the people and food.

3. The population figures and rat and human plague figures are discussed. The rat and flea population figures over a twelve month trapping period are given and notes made on interesting biological problems arising out of these figures.

4. The male and female ratios in a Rattus population in plague endemic areas offer an interesting problem for further investigation. It would be instructive to find out what are the factors responsible for high female ratios and the significance of such female dominance being peculiar to endemic areas.

5. The field rodent and flea survey figures are discussed. Although an interchange of fleas takes place between them and house rats, plague remains absent from such communities.

6. There is no evidence to show that there is carriage of infection from endemic centres, either by rats, fleas, merchandise or man.

7. A comparison is drawn between a Kenya endemic centre and an Indian one, similarities and differences being noted. The similarities are that both areas are extremely fertile, large crops of cereals being grown, and the diets of both man and rats are confined to this inadequate source of nourishment. The great differences between Indian and Kenyan endemic centres are the flea species present and that India suffers a much heavier mortality rate in man than does Kenya.

8. It is suggested that the low incidence of plague in man in Kenya is partly explained by the habits of Rattus, which in the typical dwellings of native areas nests in the thatch. Its ectoparasites are then unlikely to come into contact with man. In buildings where rats nest underground contact between its flea (then Xenopsylla cheopis) and man is likely to be very close and constant, and areas containing such buildings are usually distinguished by the epidemic nature of the disease.