Showing papers on "Malaria published in 1973"
Book•
01 Jan 1973
137 citations
Journal Article•
90 citations
TL;DR: In this paper, the removal of leucocytes from malaria infected blood was studied. But the leucocyte removal was performed in a laboratory setting, not in the field of agriculture.
Abstract: (1973). The removal of leucocytes from malaria infected blood. Annals of Tropical Medicine & Parasitology: Vol. 67, No. 2, pp. 249-250.
75 citations
TL;DR: The pattern of fetal birthweight distribution was examined in singleton babies bora to several groups of pregnant Nigerian women and it was found that maternal anaemia was itself associated with retardation of fetal growth and that this was most marked in the presence of sickle‐cell anaemia.
67 citations
TL;DR: The virtual absence of positive I.F.A. tests in children below the age of 5 years confirms the absence of transmission during the past 5 years and indicates the value of this serological method used in the field on a large scale.
65 citations
TL;DR: This paper uses published epidemiological data to demonstrate an interaction among the species of human malaria that is expected from ecological and evolutionary theory and suggests that a malaria vaccine need not be specific to each of the species, strains, or antigenic variants of Plasmodium in order to be effective.
Abstract: Human hosts exposed to infection are model systems for studying the interactions of parasites with each other and with their environments. This paper uses published epidemiological data to demonstrate an interaction among the species of human malaria that is expected from ecological and evolutionary theory. Under certain circumstances, there are fewer mixed malarial infections in human beings than would be expected if infection with one species of malaria were independent of infection with each other species. This reduction in the number of mixed infections is strongly associated with enlargement of the spleen of the human hosts, and less strongly with situations that stimulate immune responses. Such heterologous resistance is probably best explained as a partial heterologous immunity to malaria in man, since experiments in other mammals have shown that immune mechanisms can eliminate or reduce the level of mixed infections. Though competition among mixed malaria species for nutrients in limited supply in...
63 citations
Journal Article•
TL;DR: The immunoglobulin levels in sera from mothers and newborn infants were studied in Gambian, Nigerian, and Swiss populations and no evidence was found to indicate that malaria infection of the placenta induced an immune response in the fetus.
Abstract: The immunoglobulin levels in sera from mothers and newborn infants were studied in Gambian, Nigerian, and Swiss populations. The maternal levels of IgG and IgM, but not IgA, varied with locality. As they were highest in Gambian and lowest in Swiss women, they may have reflected differences in the endemicity of infectious diseases in the different environments. The neonatal Ig levels showed less variation than the maternal. Neither maternal nor neonatal levels of IgG showed any consistent relationship with birthweight; however, when maternal IgG levels were low the neonatal levels tended to exceed them. The mean IgG and IgM levels were higher in Gambian than in Nigerian or Swiss infants; the higher IgM values may have been due to more frequent antigenic stimulation in utero in the Gambian group. Evidence of placental malaria, mainly falciparum, was found in 76 of 234 Gambian women. No parasites were found in the blood from any neonate. The maternal levels of IgG, but not of IgM or IgA, were significantly elevated in association with placental malaria. The neonatal immunoglobulin levels were not influenced by placental malaria and no evidence was found to indicate that malaria infection of the placenta induced an immune response in the fetus.
47 citations
TL;DR: The possible relationship between the absence of a micropore in the sporozoites of the rodent species and the well known poor infectivity of these parasites is discussed.
Abstract: 1. 1. The ultrastructure of sporozoites of 5 species of malaria parasites, Plasmodium vivax, P. cynomolgi, P. gallinaceum, P. berghei nigeriensis and P. vinckei chabaudi has been studied both in the o6cyst and the salivary gland of the mosquito. 2. 2. Micropores were readily found in both situations in P. vivax, P. cynomolgi and P. gallinaceum , but none were detected in the rodent species. 3. 3. Usually only 1 micropore was seen in the sporozoite; 2 micropores were seen in single sporozoites of P. cynomolgi , and on one occasion 6 were seen on the surface of the maturing sporoblastoid in P. vivax . 4. 4. Sections of 2,000 sporozoites were examined in each group, the incidence of the micropore was rather over 1%, though it reached 5% in sporozoites of P. cynomolgi in the salivary gland. 5. 5. There was little difference in the incidence of the micropore between the oocyst and salivary gland. 6. 6. The possible relationship between the absence of a micropore in the sporozoites of the rodent species and the well known poor infectivity of these parasites is discussed.
40 citations
37 citations
Journal Article•
35 citations
TL;DR: It was found that in the spleen parasitized cells are: (1) phagocytized in toto by cordal macrophages, (2) pitted of parasites, and (3) hemolyzed in the splenic microvasculature.
TL;DR: Two new investigational antimalarial drugs developed by the U.S. Army Malaria Research Program were tested in patients with multi-drug-resistant falciparum malaria from Vietnam and cured 13 patients treated in the United States and 23 of 26 patients in Vietnam.
Abstract: Two new investigational antimalarial drugs developed by the U.S. Army Malaria Research Program were tested in patients with multi-drug-resistant falciparum malaria from Vietnam. WR 33063, a phenanthrene methanol, cured 13 patients treated in the United States. All of these patients had suffered multiple recrudescences after treatment with standard antimalarial drugs. In addition, 23 of 25 patients with acute attacks of falciparum malaria treated in Vietnam were cured. The rate of clinical response was prompt. WR 30090, a quinoline methanol, similarly cured eight patients with multiple recrudescences in the United States and 23 of 26 patients in Vietnam. Adverse effects associated with the drugs were not seen. These drugs signify a major advance in the chemotherapy of drug-resistant falciparum malaria.
TL;DR: WR 30090 at a dose of 230 mg every 8 hr for 6 days has proven to be a safe, well-tolerated compound with photosensitivity proving to beA minor consideration.
Abstract: WR 30090 at a dose of 230 mg every 8 hr for 6 days has proven to be a safe, well-tolerated compound with photosensitivity proving to be a minor consideration. WR 30090 was found to be an effective medication for the treatment of acute malaria caused by several strains of Plasmodium falciparum. At the dose of 230 mg every 8 hr for 6 days, all of six men infected with a chloroquine-susceptible strain (Uganda I) were cured, all of 13 subjects infected with moderately chloroquine-resistant strains (Malayan Camp, Malayan Taylor, and Philippine Per) were cured, and 19 of 23 subjects infected with strains highly resistant to chloroquine (Vietnam Smith and Vietnam Crocker) were cured. All of five subjects infected with the chloroquine-resistant Vietnam Marks strain were cured with only 3 days of therapy. Blood-induced P. vivax (Chesson strain) infection showed a mixed response. Six out of seven volunteers were cured when treated for 3 days with WR 30090. The one recrudescence responded to a repeated course of therapy for 3 days. However, recrudescence occurred in one volunteer treated for 6 days. Treatment with WR 30090 failed to cure sporozoite-induced P. vivax (Chesson strain) infection in any of four subjects. In all subjects treated, there was good suppression of parasitemia and relief of symptoms. The susceptibility of the strains of malaria to WR 30090 to some degree parallels their susceptibility to chloroquine.
Journal Article•
TL;DR: It is found advisable to treat pregnant patients who are visiting areas where malaria is endemic prophylactically with chloroquine phosphate, 500 mg orally once a week, starting before entering the endemic area and continuing the treatment until 6 weeks postpartum.
TL;DR: The efficacies of combinations of sulfalene.trimethoprim (SF-T) and sulphormethoxine-pyrimethamine (S-P) against falciparum malaria in Thailand were assessed and no significant toxic side reactions were observed in subjects administered either one of the combination treatments.
Abstract: The efficacies of combinations of sulfalene.trimethoprim (SF-T) and sulphormethoxine-pyrimethamine (S-P) against falciparum malaria in Thailand were assessed. ThirtY'one patients were given a single dose of SF-T (1 g SF and 0.5 g T) and 34 patients were given Sop (1 g Sand 0.05 g P). Radical cures were observed in 84% of the patients given SF-T and in 91 % of those given S-P Clearances of fever and asexual parasitemias were similar. Factors of previous malaria infections as indicated by both the patients' medical history and by the presence of malaria fluore3cent antibodies and prior antimalarial ihtake showed no apparent influence on treatment outcome. No significant toxic side reactions were observed in subjects administered either one of the combination treatments. A plan for the field use of the long-acting sulfonamide combinations is proposed. Chloroquine-resistant falciparum malaria was ii:::,t reported from Thailand in 1962.' Since that time. investigations performed in Thailand by D:--. Tranakchit Harinasuta,2 SEATO 1vledical Resea:ch LaboratorylS and Thailand Malaria Operationai Research Unit" have shown rates ranging iron 50% to 100%. Because of this problem of chloroquine resis~ (znce and in view of the fact that administration 01 quinine to large numbers of patients in the field is operationally impractical, the need in TnaiIand for a simple and effective regimen against falcipal.:"um malaria is most urgent. Presently, two sulfonamide combinations have the potentlal for meeting this need. These are: 1) sulfalene-trimethoprim (SF-T), and 2) sulphor. Accepted 28 September 1972 ... This study was supported by the Agency f01 International Development, U. S. Department of State, and the U. S Almy, Department of Defense. This is contribution No. 1047 from the Army Malaria Research Progum. t Formerly Chief, TMORU. Plcsent address' American Embassy (Central America .Malatia. Research Station), APO New YOlk 09889. ~Forrncrly EpidemIOlogist, TMORU. § U. S. Army Medical Component, SEATO II Trad Pro{rincial Hospital, Thailand. methoxine (Fanasil,1il Roche)-pyrimethamine (S·P). The purpose of this study ''las to assess these two combinations agains t falciparum malaria in adult Thai males, with respect to rapidity of action, cure rate, the effect of pree."'{isting malaria antibodies on cure rate, and possible side effects, especially side effects in individuals whose erythrOlytes are deficient in glucose-6-ph05phate dehy· drogenase (G-6-PD) activity. MATERIALS ANn :urETHODS The site selected for study was Trad Province, located in Southeast Thailand approximately 400 km from Bangkok (see Fig. 1). Previous investigations have shown that the majority of Plasmodimn jalciparum, strains from this area are chloroquine resistant In 1968, investigations of the chloroquine sensitivity of P jaidparum were conducted in an area 50 km north of Trad Hospital.' Treatment failures following administration of chloroquine were obsen'cd in 8 (80%) of 10 subjects who receIved a total dosage of 25 mg (base)/kg and in 19 (100%) of 19 additional subjects who received a single. dose at 10 mg (base)/kg. Just prior to the present study, Colwell and co-workers reported, from the same hospital, a chloroquine-resistance rate of 93% in
TL;DR: The abnormalities of the coagulation tests in this study are explained by hypersplenism, drug toxicity, and liver disease.
Journal Article•
Journal Article•
TL;DR: The results showed the development of antigenaemia during the third year of life, the highest prevalence was around 14 years and thereafter it gradually declined.
Abstract: A random survey of hepatitis B antigen in a rural community in Kenya is reported. The results showed the development of antigenaemia during the third year of life. The highest prevalence was around 14 years and thereafter it gradually declined. The antigen was found significantly more frequently in males than in females. There was no evidence of an inherited tendency and no association with malaria.
TL;DR: Out of over a quarter million compounds that have recently been screened, a handful are now in clinical trial and are showing great promise for the treatment of multiple resistant falciparum malaria.
Abstract: New antimalarial drugs are required, partly because of the emergence of drug resistant strains of malaria parasites and partly because better compounds are needed to cure relapsing tertian malaria. In reviewing the diverse modes of action of currently used anti-malarials, against a background of the pathogenesis of malaria, attention is drawn to deficiencies in our knowledge. Even less do we understand how the malaria parasite becomes resistant to certain drugs, in particular chloroquine. New approaches to the problem include the application of combinations of existing antimalarials, and the search for new drugs on an unprecedentedly vast scale. Out of over a quarter million compounds that have recently been screened, a handful are now in clinical trial and are showing great promise for the treatment of multiple resistant falciparum malaria. The paper concludes by summarizing current recommendations for the prophylaxis and therapy of malaria due to drug resistant parasites.
Journal Article•
TL;DR: While the physician at the First Australian Field Hospital at Vung Tau during March, April and May, 1970, the period covering the Plasmodiwm viva:c epidemic shown in his Figure 3, his recollection of this period is still very clear.
Abstract: SIR: I was Interested to read Professor Black's paper on \"Malaria In the Australian Army in South Vietnam\" (Journal, June 30), more particularly since I was the physician at the First Australian Field Hospital at Vung Tau during March, April and May, 1970, the period covering the Plasmodiwm viva:c epidemic shown In his Figure 3. My recollection of this period Is still very clear, and my records from the field enforce It. I should like to make the following comments.