Annual report of the Medical Department / Tanganyika Territory.

  • Tanganyika. Medical Department.
Date:
[1953]
Catalogue details

Licence: Public Domain Mark

Credit: Annual report of the Medical Department / Tanganyika Territory. Source: Wellcome Collection.

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    46. The Makonde plateau is about forty miles across, at an average height of 2,200 feet above sea level and standing 1,000 feet above the surrounding plain. The population of the plateau is approximately 155,000, living in small adjacent villages or groups of houses, separated by agricultural land or bush. Du.ring the dry season of May to December water has to be fetched from the bottom of the plateau and is stored in pots deeply embedded in the floors of the houses. Thus the pots are very rarely completely emptied, and these domestic reservoirs make ideal breeding places for aedes and culex mosquitoes which abound. 47. The epidemic actually began in October, 1952, although a few scattered points had been affected previously. There is no explanation of its origin. Once the outbreak got under way the spread was rapid and involved sixty to eighty per cent of the population of each village within two or three weeks from the occurrence of the first case. The incubation period varied from three to twelve days. The onset was typically sudden with no prodromal symptoms. The pain incapacitated some within a few minutes, others within several hours. There was a rapid rise in temperature to a level varying from 102° to 105 °F., occasionally accompanied by a rigor. The pyrexia continued from one to six days and was followed by an apyrexial period of one to three days; the majority of patients then showed a secondary rise in temperature from 99° to 101°F., although this was by no means constant. Pain in the joints was extremely severe, completely immobilizing many patients and preventing sleep. It was localized in the large joints and was aggravated by movement. Morphia was the only adequate analgesic. Headache was often present, but there were no eye symptoms. In 80 per cent of the cases there was an irritating maculo-papul'ar rash, mainly on the trank and extensor surfaces of the limbs, which usually accompanied or followed the secondary rise in temperature. There was usually some tachycardia in association with the initial rise in temperature. There was no general glandular enlargement or tenderness. As a late effect apyrexial recurrence of joint pains without other evidence of ill-health was common, and in some persons continued for up to four months aftdr the original illness. There were no deaths directly attribut¬ able to the epidemic. 48. The greatest differences in the clinical picture between this epidemic and most other epidemics of dengue lie in the absence of adenopathy, the lack of eye symptoms and the long continuance of chronic joint pains. The total picture of the epidemic, however, closely resembles that of an epidemic of dengue, the diagnosis being strengthened by the rapid spread of the disease amongst a people who provide breeding places in their houses for very large numbers of aedes mosquitoes. 49. In February the area was visited by a team of investigators from the Virus Research Institute, Entebbe, who collected sera from patients in the acute phase, from three geni of mosquitoes (aedes, culex and anopheles), and from bed bugs which were very abundant. The Institute subsequently isolated virus from the acute phase sera, the three types of mosquitoes and from the bed bugs. The determination of the status of the “chikungunya” virus has proved unexpectedly difficult. A serological relationship has been shown between two known strains of dengue (the Hawaian and the New Guinea B.) and the “chikungunya” virus, but there are also sharp