Showing papers in "Transactions of The Royal Society of Tropical Medicine and Hygiene in 1965"
364 citations
TL;DR: The findings strongly support the conclusions of previous studies in the field that Anopheles funestus was the vector of ONN virus, and that A. gambiae was also involved.
Abstract: Mosquitoes and bed-bugs were collected in 1959–1960 from places in Uganda and Kenya affected by the o'nyong-nyong epidemic. Tests indicated that 39 of 144 pools containing 5,784 Anopheles funestus , and 15 of 206 pools of 6,933 A. gambiae contained o'nyong-nyong (ONN) virus. No isolation was made from 60 pools containing 1,837 culicine mosquitoes of at least 15 species, or from 13 pools of more than 1,561 bed-bugs. Infected A. funestus and A. gambiae caught in the field maintained ONN virus for at least 20 and 13 days respectively, but limited transmission trials with monkeys and infant mice, through these mosquitoes, were unsuccessful. Transmission was, however, obtained with laboratory-infected mosquitoes of both species. The findings strongly support the conclusions of previous studies in the field that A. funestus was the vector of ONN virus, and that A. gambiae was also involved.
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TL;DR: On the basis of urological disease only, endemic urinary schistosomiasis has a considerable adverse effect on the economy of a country such as Tanzania where foci of disease are widespread.
Abstract: An account is given of the effects produced by endemic urinary schistosomiasis upon the children attending different schools in the Mwanza Region of Tanzania. At Usagara, where the incidence of infection rises to become 100% in the children of standard 4, up to 37% of the standard 6 pupils have irreversible lesions of the urinary tract. Nearby, where infection is less prevalent, there is a coincident decrease in lesions of the urinary tract. It is firmly established that the lesions—calcified bladder, deformity of the ureter, and hydronephrosis—are due to schistosomiasis, and that their prevalence is related to the weight of infection. Lesions occur even in the youngest examined, aged 6, but the prevalence of deformity of the ureter probably increases with age. There is a very marked and significant difference between boys and girls, hydronephrosis being much rarer in girls, but other lesions are equally common. On the basis of urological disease only, endemic urinary schistosomiasis has a considerable adverse effect on the economy of a country such as Tanzania where foci of disease are widespread. Pulmonary and systemic hypertension were not seen as complications of urinary schistosomiasis in the children studied, but pathological blood urea levels occur.
63 citations
TL;DR: It is suggested that the recorded history of the movement of infected persons, the belief then current that G. morsitans did not transmit sleeping sickness, and the early incidence and localization of cases in Nyasaland and Northern Rhodesia are consistent with the conclusion that a virulent strain of Trypanosoma infective to human beings was imported from the epidemic areas of the Congo.
Abstract: The history is given of sleeping sickness, of both the Gambian and Rhodesian types, in Nyanza Region, Kenya, leading up to the explosive outbreak, in Alego and the surrounding locations in 1964, of T. rhodesiense infections transmitted by G. fuscipes ( G. palpalis fuscipes ). Some account is given of the characteristics of this epidemic, of the conditions that may have contributed to it and of the danger of spread to other parts of Kenya. Since this epidemic is in marked contrast to the normal association of T. gambiense with tsetse of the G. palpalis group, and of T. rhodesiense with the G. morsitans group, the reasons for these associations are considered and it is concluded that the usual combinations are the result of selective factors operating in the different conditions in which the trypanosome strains are transmitted. Laboratory and field evidence is quoted to show that there is no reason why, given suitable conditions, either type of trypanosome should not be transmitted by tsetse of either group. It is suggested that the recorded history of the movement of infected persons, the belief then current that G. morsitans did not transmit sleeping sickness, and the early incidence and localization of cases in Nyasaland and Northern Rhodesia, are consistent with the conclusion that, about 1908, a virulent strain, or strains, of Trypanosoma infective to human beings was imported from the epidemic areas of the Congo to parts of Nyasaland and Northern Rhodesia infested with tsetse of the G. morsitans group, and that this strain, or strains, capable of infecting game animals and being re-transmitted from them, gave rise to what is now known as T. rhodesiense .
51 citations
51 citations
TL;DR: It is suggested that, at least in Nigeria, the source of food of the flies is the main factor involved in determining the level of infection with trypanosomes in Glossina.
Abstract: An examination is made of previously published data on the trypanosome infection rate and the natural hosts, as determined by serological tests, of 9 species of Glossina from various localities in Nigeria.
A relationship is demonstrated between a high total infection rate and a large proportion of meals derived from Bovidae (particularly bushbuck (Tragelaphus scriptus), with buffalo (Syncerus nanus) important in some localities). Infection rates and the natural hosts, as determined by the measurement of red blood cells found in the flies, of two species of Glossina in Northern Nigeria were recorded by Lloyd, Johnson, Young and Morrison (1924). An examination of their data shows that a similar relationship exists between feeds derived from Bovidae and total trypanosome infection rate.
Species of Glossina which had fed mainly on Suidae usually had fewer infections of T. vivax group of trypanosomes than those which had fed mainly on Bovidae; the numbers of T. congolense group infections were approximately the same in the two groups of species.
It is suggested that, at least in Nigeria, the source of food of the flies is the main factor involved in determining the level of infection with trypanosomes in Glossina. The importance of other factors, particularly temperature, is discussed.
51 citations
TL;DR: The administration of cortisone in daily doses of 75 mg.
Abstract: The administration of cortisone in daily doses of 75 mg. per kg. subcutaneously to albino mice increased susceptibility to A. caninum infection, perhaps by suppression of immunity.
Pre-infection treatment with cortisone did not influence susceptibility to infection more than treatment started on the day of infection.
The average percentage of larvae recovered from the cortisone-treated mice was significantly greater than that of untreated control mice after 5 days of infection.
Of all organs examined, the maximum numbers of larvae were obtained from lungs of both the test and control groups of mice for a noticeable period, the former group showing considerably higher recovery than the latter from the 3rd day till 10 days after infection.
The mice, after cortisone treatment, did not provide a satisfactory medium to A. caninum larvae for further development even at 14 days after infection, indicating a poor host-parasite adaptation.
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47 citations
TL;DR: It is concluded that the fluorescent antibody test is not useful for the detection of past or present infection with L. mexicana.
Abstract: The indirect fluorescent antibody technique was used to stain smears of the leptomonads of 10 strains of Leishmania spp. including L. donovani, L. infantum, L. tropica, L. braziliensis braziliensis, L. braziliensis pifanoi and L. mexicana, and the Leishman-Donovan bodies of some strains. The sera used successfully and giving a strong reaction were from rabbits artificially immunized by leptomonads of all the above strains, and human sera from patients infected with Mediterranean infantile kala-azar, South American kala-azar, South and Central American muco-cutaneous and cutaneous leishmaniasis. Other sera used successfully but giving a weak reaction were from rabbits artificially immunized by Leishman-Donovan bodies of L. mexicana, human sera from patients infected with leishmaniasis tegumentaria diffusa, uta and British Honduran chiclero's ulcer, and serum from monkeys infected in the laboratory with L. mexicana and L. braziliensis. Reactions were less strong with Leishman-Donovan bodies as slide antigen than with leptomonads. No differentiation of strains was possible by serial dilution of sera used in the test, as all sera stained all antigen preparations at more or less the same intensity, indicating a group antigen-antibody reaction in reference to this method. Specific absorption of sera completely eliminated the reaction regardless of the antigen used for absorption. Sera sent from British Honduras from patients with chiclero's ulcer, non-immune subjects and others, were tested for antibodies by the fluorescent antibody technique. No correlation was obtained between disease or possible exposure and positive fluorescent antibody results. It is concluded that the fluorescent antibody test is not useful for the detection of past or present infection with L. mexicana.
TL;DR: HI test results with Oriboca virus suggest that this or a closely related member of Group C exists in Angola, and that Sindbis, chikungunya, Semliki Forest, Wesselsbron, Zika, H 336, West Nile, Bunyamwera and Germiston viruses have been active, predominantly in the north-western region.
Abstract: Sera collected in 1960 from 492 indigenous residents of 14 widely scattered localities in Angola were tested for HI antibodies against 18 viruses: 5 from Group A, 9 from Group B, 1 from Group C, 2 from the Bunyamwera Group, and Rift Valley fever virus. Results of these tests indicated that the prevalence of antibodies was greatest in the 6 localities sampled in the north-western coastal and plateau region. Sera positive in the HI test were further tested with the respective viruses by mouse neutralization test. Analysis of these results according to sera positive for only one virus of Group A, B or Bunyamwera indicated that Sindbis, chikungunya, Semliki Forest, Wesselsbron, Zika, H 336, West Nile, Bunyamwera and Germiston viruses have been active, predominantly in the north-western region, and that Spondweni virus has been present. There was no evidence that Mayaro or Middelburg virus has infected the population sampled, or that Ntaya, dengue 1 or dengue 2 virus has been present. In 3 localities in the north-west interpretation of results with Group B viruses was complicated by the fact that some of the donors had been vaccinated against yellow fever. HI test results with Oriboca virus suggest that this or a closely related member of Group C exists in Angola. In additional neutralization tests, one or more sera from children and adults in each of the 6 north-western localities protected against Lumbo (California complex), Pongola or Bwamba fever virus.
TL;DR: A significant anaemia, progressively greater with the severity of the general condition, was found to accompany kwashiorkor, and in 5 children loaded with histidine, FIGLU was not excreted until the block in the metabolism of this amino acid was corrected.
Abstract: A significant anaemia, progressively greater with the severity of the general condition, was found to accompany kwashiorkor. It was partly masked by haemoconcentration when the child was admitted, but later became more evident as the serum albumin increased, probably because the blood volume was enlarged. The anaemia resulted from diminished erythroid activity in the bone marrow, which was believed to be an effect of the impaired protein metabolism. Reticulocyte and platelet counts were low. If hookworm or malaria parasites were present, there was more anaemia. Treatment with milk diets caused an increase in marrow activity which gradually corrected the anaemia. There was a remarkable thrombocytosis. The increased activity appeared to be due to the protein of the diets, not to vitamins or haematinics. Of the 100 children examined, 15 were megaloblastic on admission, or became so later. In 5 children loaded with histidine, FIGLU was not excreted until the block in the metabolism of this amino acid was corrected. The excretion stopped after the injection of folic acid.
TL;DR: The present survey offers no conclusive evidence that this virus has been active among the population sampled, but neutralization test results gave further evidence of activity of a wide spectrum of viruses, but showed that immunity levels were highest with Sindbis, West Nile, Wesselsbron, Bunyamwera and Germiston viruses.
Abstract: Sera collected in 1959 from 602 residents of 19 localities in the Caprivi Strip and Bechuanaland Protectorate were tested for HI antibodies against 15 viruses—4 from Group A, 7 from Group B, 1 from Group C, 2 from the Bunyamwera Group, and Rift Valley fever virus. Results of these tests were largely negative for the 5 localities in the Kalahari Desert, but indicated a great deal of virus activity in the Caprivi Strip and the Okavango Basin. Sera positive in the HI test were further tested with the respective viruses by the mouse neutralization test. Selected sera were also tested for neutralizing antibodies against 4 other ungrouped viruses. Neutralization test results gave further evidence of activity of a wide spectrum of viruses, but showed that immunity levels were highest with Sindbis, West Nile, Wesselsbron, Bunyamwera and Germiston viruses. The results of yellow fever neutralization tests with sera collected in the Okavango Basin during 2 previous surveys are reviewed. The present survey offers no conclusive evidence that this virus has been active among the population sampled.
TL;DR: There seems to be a satisfactory correlation between albumin and plasma losses on the one hand, and numbers of hookworms harboured on the other, and factors relating to the use of 131I-labelled albumin as a measure of albumin metabolism are discussed.
Abstract: 17 patients infected with hookworms were used in a study of albumin metabolism and faecal albumin loss. They were compared with 9 controls. Factors relating to the use of 131 I-labelled albumin as a measure of albumin metabolism are discussed. Some doubt has recently been expressed as to whether faecal activity appearing in this method represents wholly albumin breakdown in or near the gut, or partly endogenous breakdown with subsequent secretion of iodide. The weight of evidence has indicated the former. The method of measuring salivary excretion of iodide and its fate may need elaborating. There seems to be little division of opinion about the bowel origin of excessive albumin losses. It is claimed that hookworm patients lose excessive albumin into their gut. The loss of albumin is roughly 0·1 g. per 100 hookworms of the species Necator americanus . This is equivalent to the loss of 3 ml. plasma per 100 hookworms. This figure agrees very well with other published work based on red cell losses estimated by 51 Cr. There seems to be a satisfactory correlation between albumin and plasma losses on the one hand, and numbers of hookworms harboured on the other. Female hookworms were in the preponderance (ratio 3 : 2). In Kampala only N. americanus was found. The worms were themselves devoid of radio-activity.
TL;DR: The opinion is expressed that the specificity of immune processes and the reproductive capacity of pre-erythrocytic schizonts combine to indicate that the density of viable sporozoites inoculated may be a factor of importance in shaping the pattern of malaria in both the individual and the community.
Abstract: 1. 1. Recent advances in knowledge concerning plasmodial biology and acquired immunity in malaria are examined, and their possible effects upon the epidemiology of malaria considered. 2. 2. The opinion is expressed that the specificity of immune processes and the reproductive capacity of pre-erythrocytic schizonts combine to indicate that the density of viable sporozoites inoculated may be a factor of importance in shaping the pattern of malaria in both the individual and the community. 3. 3. Strain specificity of immunity is discussed and attention drawn to the need for careful control of the size of challenging infections in the course of studies designed to elucidate intra-species differences in plasmodial antigenicity.
TL;DR: A mature oocyst, considered to be of Plasmodium falciparum, was found to contain 9,555 sporozoites.
Abstract: A mature oocyst, considered to be of Plasmodium falciparum, was found to contain 9,555 sporozoites.
TL;DR: 1,000 consecutive cases of venereal disease have been analysed and it is suggested that the latter assume a very significant role, and that any effective eradication programme must take social factors into consideration.
Abstract: 1,000 consecutive cases of venereal disease have been analysed, and the social factors facilitating the spread of this group of diseases are examined and discussed. It is suggested that the latter assume a very significant role, and that any effective eradication programme must take social factors into consideration.
TL;DR: It is concluded that surgical removal of the plug of dead flukes and drainage of the biliary tree are essential in the management of the condition and that it should be carried out as early as possible.
Abstract: Over a period of 16 years, to the University Department of Medicine, Queen Mary Hospital, 11 patients were admitted deeply unconscious, with high fever and showing varying degrees of jaundice. In all the coma was associated with severe hypoglycaemia, and correction of this resulted in restoration of consciousness. The histories of the last 10 patients were remarkably similar. After 1–4 days of fever and right upper abdominal discomfort there were repeated rigors associated with distressing distending pain over the liver coupled with vomiting. All lost consciousness within 24 hours of the onset of rigors. The laboratory findings are briefly described. The findings at necropsy in 9 and at laparotomy in 2 were those of a diffuse suppurative pancholangiitis associated with obstruction tot he extrahepatic ducts by large numbers of dead Clonorchis sinensis . It is concluded that surgical removal of the plug of dead flukes and drainage of the biliary tree are essential in the management of the condition and that it should be carried out as early as possible. An investigation of the cause of the hypoglycaemia is described and it is concluded that it results from a hepatectomy-like effect. How the infection exerts this effect has not been determined. It is not due to necrosis of liver cells and is rapidly reversible through adequate treatment.
TL;DR: An account is given of the past history of yellow fever cases and epidemics in eastern Africa, and of the field and laboratory studies which led to the incrimination of Aedes (Stegomyia) simpsoni and Ae.
Abstract: An account is given of the past history of yellow fever cases and epidemics in eastern Africa, and of the field and laboratory studies which led to the incrimination of Aedes (Stegomyia) simpsoni (Theobald) and Ae. (S.) africanus (Theobald) as vectors of the virus, the former mainly in a peri-domestic habitat and the latter in forest, particularly the forest canopy.
TL;DR: A study of human cases of dermal leishmaniasis shows that the infection is not confined to “high bush” but may be present in bush of any type, and the advisability of employing prophylactic vaccination under certain conditions is worth considering.
Abstract: A study of human cases of dermal leishmaniasis shows that the infection is not confined to “high bush” but may be present in bush of any type. The advisability of employing prophylactic vaccination under certain conditions is worth considering. A rat was found to be infected with Leishmania mexicana, but there was no Leishmania among parasites obtained from lizards. 14 species of Phlebotomus were found, and preliminary observations were made on age changes and other features. Attempts to ascertain the natural infection rate, by inspection and by injection into hamsters, gave negative results, and possible reasons for this are discussed.
TL;DR: A high incidence of toxoplasma antibodies has been found in adult Africans in the Niger Delta, similar to the incidence found in tropical areas of the New World.
Abstract: A high incidence of toxoplasma antibodies has been found in adult Africans in the Niger Delta. This is similar to the incidence found in tropical areas of the New World.
TL;DR: The specificity of the test was demonstrated by experiments on immunization, by absorption studies and by absence of cross-reactions in the sera of man and animals infected with a wide range of parasites.
Abstract: The preservation of a pure suspension of Toxoplasma gondii for use as antigen in a direct agglutination test for Toxoplasma antibodies is described. The test is macroscopic and avoids the use of live parasites; it is easily carried out and the results obtained have shown good correlation with other tests in common use. The specificity of the test was demonstrated by experiments on immunization, by absorption studies and by absence of cross-reactions in the sera of man and animals infected with a wide range of parasites. Agglutinins, which we have termed ‘natural’ agglutinins, appear to occur in some sera and can be absorbed with suspensions of T. gondii . The distribution of antibodies in approximately 500 blood donors engaged in sedentary occupations around London was determined. Males and females were equally affected and age appeared to be without influence on agglutinating titres. Chronic infection in rats gave rise to high agglutinating titres, and growth was retarded.
TL;DR: Sera from indigenous New Guineans tested for auto-immune complement fixation with saline extracts of human liver and kidney gave titres exceeding 1 in 5 and 22 of these sera had gamma-globulin levels exceeding 1·50 g per 100 ml.
Abstract: 804 hypergammaglobulinaemic sera from indigenous New Guineans were tested for auto-immune complement fixation with saline extracts of human liver and kidney. 30 sera gave titres exceeding 1 in 5 and 22 of these sera had gamma-globulin levels exceeding 1·50 g. per 100 ml. A possible reason for this finding may be the action of environmentally induced stresses leading to chronic tissue destruction (such as liver damage arising from malnutrition and malaria) and the heightened capacity for immune response which may result from the high antigenic load carried by tropical peoples.