Malaria in Nyasaland

Abstract

Malaria in Nyasaland By J. GORDON THOMSON, M.B., Ch.B. THis visit to Nyasaland was made possible by a grant from the Milner Research Fund, and I am indebted to the Colonial Office and to the Government of Nyasaland for their help and assistance during my work. I have specially to tender my thanks to His Excellency the Governor, Sir Hubert Young, and to all those serving with him in an official capacity for their courtesy and kindness. Dr. A. D. J. B. Williams, the Director of Medical Services, and all the medical men both in Government Service and in Missions, made it possible for me to examine numerous cases of children and women during pregnancy. I also owe a deep debt of gratitude to my friend and collaborator, Dr. W. A. Lamborn, who not only helped, but stimulated and encouraged me throughout this investigation. [The topography and climate of the country were then described.] The Population of Nyasaland, with a Note on Vital Statistics. When the 1901 census was taken, the total European population numbered only 314; by 1911 this had increased to 766 and at the last census (1931) the increase was still maintained, there being 1,975 persons, mostly engaged in Government employ, Christian missions, planting, commerce, and railways. At the time of the last census there were 1,591 Asiatics, mostly traders, while the native population totalled about 1,599,880. It is greatly to be regretted that, as was pointed out by Follit (1932), the potential value of these accurate census returns largely is stultified by the absence of birth and death records and that it is not possible to determine a general death-rate, a birth-rate, or an infantile mortality rate. The population was divided, at the time, into three age-groups, viz. 0 to 5 years, 5 to 15 years, and adults. Follit considers it to be a fair deduction to make from the census returns that an enormous wastage of life occurs between the ages of 0 to 5 years, and that in every 100 infants born probably not more than 30 survive the first year of life, and not more than 10 in every hundred live to be 6 years of age. In the Annual Medical Report for last year, Dr. Williams (1934) gives a short note on vital statistics and quotes an experiment on registration which was started at Fort Manning in 1932. The system adopted is not official, but chiefs and village headmen are co-opted and native recording officers are employed. There is no compulsory registration and the margin of error must be considerable. Little or no attempt has been made to record the causes of death. The figures in this experiment at Fort Manning are as follows: birth-rate per 1,000 was 68-2 and death-rate per 1,000 was 25-8. The infantile death-rate per 1,000 births was 97-3 and the stillbirth-rate per 1,000 live births was 89-3. The infantile mortality is very high, and when the mode of life of the natives is considered, this is not surprising. It is quite impossible to estimate to what extent the death-rate in infants is due to malaria or to the many other prevalent diseases. Malaria is so widespread...

Interactions between malaria parasites infecting the same vertebrate host

“…This is essentially the same immune-mediated antagonism as that predicted by Cohen (1973). It is of interest to note that 50 years ago Thomson (1934) suggested that P. falciparum could reduce the prevalence of P. malariae.…”

“…In humans, the results of such inoculations have been reported by Plehn (1926), James (1931), Ciuca, Ballif & Vieru (1928, 1934, Boyd, Kitchen & Matthews (1939), Shute (1946), Covell & Nicol (1951), Jeffery (1966) and Pazzaglia & Woodward (1982). The interpretation of these experiments is often limited by lack of control infections or by the fact that the initial immunizing infection was suppressed by drugs.…”

The Consequences of Mixed-Species Malaria Parasite Co-Infections in Mice and Mosquitoes for Disease Severity, Parasite Fitness, and Transmission Success

“…Molineaux et al (42) suggested that in mixed infections of P. falciparum and P. malariae, the immune response stimulated by rising P. falciparum parasitaemias can inhibit P. malariae, but that P. falciparum survives longer due to its more rapid growth rate. This immune-mediated antagonism (43) agrees with observations suggesting that P. falciparum could reduce the prevalence of P. malariae (44).…”

Isotopic evidence that aestivation allows malaria mosquitoes to persist through the dry season in the Sahel

“…coluzzii reappear [4][5][6] . The 'dry-season malaria paradox' of dry-season mosquito persistence has been puzzling malariologists and medical entomologist for almost a century [6][7][8][9] .…”