Leonard J. Bruce-Chwatt

Bio: Leonard J. Bruce-Chwatt is an academic researcher from University of London. The author has contributed to research in topics: Malaria & Population. The author has an hindex of 21, co-authored 63 publications receiving 2178 citations. Previous affiliations of Leonard J. Bruce-Chwatt include World Health Organization.

Malaria in African Infants and Children in Southern Nigeria

Abstract: 2 series of investigations into the incidence and degree of malarial infection in 551 African parturient women in Lagos an urban and semi urban area of Southern Nigeria and their newborn infants were carried out during 1948-50. The routine technique of the investigation consisted of taking blood slides from the peripheral circulation of the mother and her newborn within 6-24 hours of delivery. A blood slide was made from a deep layer of a piece of the maternal placenta excised near the center. The weight of all newborn infants was recorded and whenever possible the progress of the infants was followed up throughout the neonatal period. The weight of all newborn infants was recorded and whenever possible the progress of the infants was followed up throughout the neonatal period. The mean incidence of malarial parasitaemia (mainly due to Plasmodium falciparum) in the sample of 323 Africa parturient women was found to be 33% somewhat higher than the usual parasite rate of the adult indigenous population. The incidence of malarial infection of the placenta was 23.8%. There were no cases of congenital malaria in 332 babies born of these mothers. The mean weight at birth of 237 babies born of mothers whose placentae were noninfected was 145 mg higher than that of 73 babies born of mothers whose placentae were found to be infected. The difference was statistically significant. There was no apparent correlation between neonatal mortality and infection of the placenta. Periodic investigation of a sample of 138 African infants followed up from the age of about 1 month through the 1st year of life and through part of the 2nd year showed that the mean parasite rate due principally to P. falciparum increased from 2.2% during the 1st quarter year to 20% in the 2nd quarter to 60-70% during the 3rd and 4th quarters and to over 80% thereafter. The infection rate when calculated in relation to the known length of exposure to infection shows that an equally long exposure leads to different frequencies of infection in the various age groups of the sample of infants investigated and that in the age group 1-3 months the parasite rate was significantly lower than might have been expected. Periodic follow-up of the mean weight curves of infection and noninfected infants indicated that the curves of both groups showed a considerable flattening out at about 5 months of age and later and that the flattening out is more pronounced in the infected group than in the noninfected. Records of 3540 autopsies performed upon children in Lagos during the years 1933-50 revealed that acute malaria can be incriminated as the cause of death in 9% of infants in 14% of children aged 1-4 years in 9% of children aged 5-7 years in 4% of older children and in 2% of adolescents. The number of deaths due to direct effects of malaria in the Nigerian population under 15 years of age amount to 35000/annum.

Chemotherapy of malaria

Abstract: Chemotherapy of malaria , Chemotherapy of malaria , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Malaria and pregnancy.

Abstract: The recent spate of reports' confirming the extension to parts of east Africa of chloroquine resistant strains of Plasmodium falciparum, which have been present for some time in other parts of the tropical world,2 3 has caused much concern. Travel for business or pleasure has now become commonplace: in 1981 some 19 million Britons spent their holidays abroad, and many of them went to various exotic areas.4 No wonder, then, that the news of changing trends in prevention of malaria by hitherto reliable drugs has caused some disquiet. In particular, many women want answers to three important questions. Does pregnancv aggravate malaria and vice versa ? Can the available drugs always protect from malaria infection ? Does the prevention of infection by antimalarial drugs have an adverse effect on the pregnancy or on the unborn child? Much has been written on these three topics and some aspects remain uncertain, but a consensus of expert opinion may be given. Malaria in general, and especially an infection with Pfalciparum, is more hazardous during pregnancy. Pregnancy appears to interfere with the immune processes in malaria,5-7 a disease which itself alters immune reactivity.8 In highly endemic malarious areas, where semi-immune adults usually have substantial acquired resistance to local strains of plasmodia, the prevalence of clinical malaria is higher and its severity greater in pregnant women, especially during the second trimester, with the greatest risk in primiparas.5 7 10 The mechanism of this phenomenon is complex, with evidence of both suppression of antibody formation and depression of cell mediated immunity.8 Malaria may cause abortion and premature labour; in tropical areas many pregnant women suffer from severe anaemia due to the infection itself and to the effects of deficiency of iron and folic acid.1' 12 The results of recent studies indicate that the anaemia of malaria is due to some extent to the immune destruction of sensitised red cells and a depression of erythropoiesis.13 Acute malaria in a pregnant woman requires speedy and complete treatment by the most effective drugs available, with full supporting medication.1

The Economic Burden of Malaria

Abstract: Malaria and poverty are intimately connected. Controlling for factors such as tropical location, colonial history, and geographical isolation, countries with intensive malaria had income levels in 1995 of only 33% that of countries without malaria, whether or not the countries were in Africa. The high levels of malaria in poor countries are not mainly a consequence of poverty. Malaria is geographically specific. The ecological conditions that support the more efficient malaria mosquito vectors primarily determine the distribution and intensity of the disease. Intensive efforts to eliminate malaria in the most severely affected tropical countries have been largely ineffective. Countries that have eliminated malaria in the past half century have all been either subtropical or islands. These countries' economic growth in the 5 years after eliminating malaria has usually been substantially higher than growth in the neighboring countries. Cross-country regressions for the 1965-1990 period confirm the relationship between malaria and economic growth. Taking into account initial poverty, economic policy, tropical location, and life expectancy, among other factors, countries with intensive malaria grew 1.3% less per person per year, and a 10% reduction in malaria was associated with 0.3% higher growth. Controlling for many other tropical diseases does not change the correlation of malaria with economic growth, and these diseases are not themselves significantly negatively correlated with economic growth. A second independent measure of malaria has a slightly higher correlation with economic growth in the 1980-1996 period. We speculate about the mechanisms that could cause malaria to have such a large impact on the economy, such as foreign investment and economic networks within the country.

Regulation and stability of host-parasite population interactions: II - Destabilizing processes

Abstract: SUMMARY (1) Three categories of biological processes are shown to have a destabilizing influence on the dynamical behaviour of model host-parasite associations: parasite induced reduction in host reproductive potential, parasite reproduction within a host which directly increases parasite population size and time delays in parasite reproduction and transmission. (2) The importance of parasitic species as regulators of host population growth is examined in light of empirical evidence. Data from two particular laboratory studies used to indicate the magnitude of this regulatory influence. Suggestions are made concerning the type of information required from field studies to facilitate critical assessment of theoretical predictions.

The ears of the hippopotamus: manifestations, determinants, and estimates of the malaria burden.

Abstract: Malarious patients experience asymptomatic parasitemia; acute febrile illness (with cerebral damage, anemia, respiratory distress, hypoglycemia); chronic debilitation (anemia, malnutrition, nervous system-related sequelae); and complications of pregnancy (anemia, low birth weight, increased infant mortality). These manifestations in patients, communities, and countries reflect intrinsic (human, parasite, mosquito) and extrinsic (environmental, social, behavioral, political, and economic conditions as well as disease-control efforts) determinants. At a minimum, between 700,000 and 2.7 million persons die yearly from malaria, over 75% of them African children. Between 400 and 900 million acute febrile episodes occur yearly in African children under 5 yr of age living in endemic areas. Although about half of these children are parasitemic, all merit consideration of malaria-specific therapy, which is becoming more problematic because of parasite resistance to drugs. These numbers will more than double over the next 20 yr without effective control. Fewer than 20% of these febrile episodes and deaths come to the attention of any formal health system. The relatively few ill patients who have any contact with the health services represent the "ears of the hippopotamus." Greatly intensified research activities and control of the intolerable burden of malaria are mandatory if economic development is to accelerate in Africa. In particular, support should be targeted to understanding and preventing malaria-induced anemia, hypoglycemia, effects on pregnancy, and neurologic and developmental impairment. To decrease and stop transmission of this intolerable scourge, there is an urgent need for malaria vaccines, newer drugs, and better vector control methods as well as the ability to improve current technologies and use them more efficiently.