Showing papers in "Transactions of The Royal Society of Tropical Medicine and Hygiene in 1939"
TL;DR: It is suggested that microfilarial blood surveys be made upon the school children, taking 1 c.c. of venous blood between 9 and 10 a.m. and giving counts comparable to counts with the standard 20 c.mm.
Abstract: It is suggested that microfilarial blood surveys be made upon the school children, taking 1 c.c. of venous blood between 9 and 10 a.m. A method is described for examining this blood; it is laked with 2 per cent. formalin solution in a conical-tip centrifuge tube and allowed to sediment. The sediment is spread on a glass slide and stained with methylene blue and eosin; this stains the microfilariae blue and the background red. The method gives counts comparable to counts with the standard 20 c.mm. drop of night blood.
210 citations
42 citations
TL;DR: The vaccination of susceptible individuals living in hyperendemic areas with live cultures of L. tropica, with a suitable control, is useful as a differential diagnostic procedure in obscure cases of leishmania-like sores in which the presence of parasites may not be demonstrable by culture and staining methods.
Abstract: 1. 1. Forty-four experimental inoculations were made on thirty-five volunteers using 4 to 50 days old first, second, third or fourth generation cultures of Leishmania tropica. Of these inoculations, thirty-five developed into typical oriental sores (80 per cent.), and nine failed to take. 2. 2. The incubation period of the experimental sores seems to be dependent upon the quantity of inoculum, the depth of inoculation and the individual variability in the degree of susceptibility. 3. 3. A single oriental sore, either experimentally or naturally acquired, confers a definite immunity to inoculation of infective L. tropica culture, and presumably to infection by natural routes. 4. 4. The reaction in immune individuals to the intracutaneous inoculation of L. tropica, with a suitable control, is specific and may be useful as a differential diagnostic procedure in obscure cases of leishmania-like sores in which the presence of parasites may not be demonstrable by culture and staining methods. 5. 5. In view of the ease and innocuousness with which oriental sores can be produced by the method described, we recommend the vaccination of susceptible individuals living in hyperendemic areas with live cultures of L. tropica. This inoculation should be made on an inconspicuous part of the body, so that the subject may be protected against lesions on the face or other exposed parts, and consequent unsightly scarring.
34 citations
TL;DR: It is suggested that the almost consistent failure to produce infection by the bite of infected sandflies may in itself indicate the existence of some reservoir host, more specifically adapted to the parasite than man or the ordinary laboratory animals which have been used for the experiments.
Abstract: 1. 1. Leishmaniasis is endemic in certain areas of the Sudan, and sporadic cases have occurred in other areas. 2. 2. Visceral, oral, and cutaneous leishmaniasis have been found existing side by side in the same areas, but the visceral form is by far the most common. 3. 3. In the endemic areas, the principal incidence of kala-azar is found in rural situations, in the vicinity of water, and associated with the presence of vegetation. 4. 4. Four small outbreaks of kala-azar have occurred among Sudanese troops on duty in uninhabited or sparsely populated country. 5. 5. Canine leishmaniasis is unknown in the Sudan, the only natural animal infection being cutaneous leishmaniasis in a horse. 6. 6. As knowledge exists at present, the only sandfly of the major group, whose distribution in the Sudan bears any significant relation to that of kala-azar is Phlebotomus langeroni. 7. 7. Epidemiological evidence points to the possibility of the infection being carried on by some alternative or reservoir host, the nature of which is at present unknown. 8. 8. It is suggested that the almost consistent failure to produce infection by the bite of infected sandflies may in itself indicate the existence of some reservoir host, more specifically adapted to the parasite than man or the ordinary laboratory animals which have been used for the experiments.
24 citations
23 citations
19 citations
TL;DR: A case of myelitis with mental confusion is described and is shown to be due to bilharzial infection and specific treatment in sufficient doses cured the mental and nervous conditions.
Abstract: 1. 1. A case of myelitis with mental confusion is described and is shown to be due to bilharzial infection. 2. 2. Three cases of mental confusion associated with bilharziasis have been referred to. 3. 3. In all the four cases, specific treatment for the bilharziasis in sufficient doses cured the mental and nervous conditions. 4. 4. In one of the cases of confusion the encephalogram showed deformity in the wall of the lateral ventricle.
17 citations
17 citations
16 citations
TL;DR: It was concluded that the ova are ingested as a result of the eating of infected liver, probably cooked, of animals which are commonly used as food, and may be more common than hitherto supposed.
Abstract: In the above paragraphs, a discussion has been presented of the occurrence of Capillaria hepatica ova in human faeces, and evidence was presented to account for this anomaly. It was concluded that the ova are ingested as a result of the eating of infected liver, probably cooked, of animals which are commonly used as food. The principal reason for this conclusion was the finding of three new hosts for C. hepatica ( Tayassu pecari spiradens, Ateles geoffroyi , and Cebus capucinus imitator ) which are used as food by the natives in the villages of Panama where this “infection” has occurred. While the finding of eggs of C. hepatica in the faeces of man was explained as probably never indicative of infection, other considerations were presented to show that actual hepatic infection in man, in which circumstance eggs would not appear in the faeces, may be more common than hitherto supposed.
16 citations
TL;DR: In other areas, having almost the same spleen rate, such a degree of immunity does not occur, and this is found to be associated with a much lower frequency of infection of anopheles, where malaria is seasonal.
Abstract: 1. 1. A summary is given of the results of a survey of a typical fully immune Bantu community, and attention is drawn to the great frequency (thirty times a year) of infection by anopheles which occurs under such circumstances. 2. 2. In other areas, having almost the same spleen rate, such a degree of immunity does not occur, and this is found to be associated with a much lower frequency of infection of anopheles (four to eight times a year). 3. 3. The essential difference in the endemic state of these two communities is clearly revealed by a comparison of the adult parasite counts, and of the seasonal variation in the parasite counts. These and other indices found in the less immune community are given in full. 4. 4. While in the first case anopheline control is economically impossible, reasons are given for concluding that it is worth attempting in the second—where malaria is seasonal. 5. 5. Since a fully immune adult shows no signs of illness attributable to malaria, he should not be given treatment for the few parasites he may carry, and babies should only be given enough treatment to remove danger to life: the object in both cases being to interfere as little as possible with the state of full immunity. 6. 6. Where on the other hand immunity is incomplete, treatment will have to be given for the clinical attacks which occur both in children and adults. Treatment should not however aim at eradication of infection, since there is an appreciable degree of immunity present, and this can only be maintained by the stimulus of persistent infection. 7. 7. Reference is made to some of the problems which are affecting non-immune Africans. 8. 8. The parasite of clinical malaria is P. falciparum , and the variations in immunity refer, to all intents and purposes, only to P. falciparum . 9. 9. Variation in the appearances of P. falciparum in immunes and in non-immunes has been observed, and is described.
TL;DR: Two species of microfilariae have been found in Kra monkeys from the Perak river, and one contained larvae apparently identical with those of Mf.
Abstract: Two species of microfilariae have been found in Kra monkeys from the Perak river.
One contained larvae apparently identical with those of Mf. malayi: this is of interest as should this identity be actual the adult should soon be found, and the existence of a reservoir host established.
The other contained a large unsheathed microfilaria, possibly an undescribed species, and almost certainly of no medical importance.
TL;DR: In this paper, the history of human trypanosomiasis in Southern Rhodesia is described and a description of the natural conditions at Gowe is given, as well as the bearing of the experience at the Gowe on the epidemiology and control of the disease.
Abstract: 1. 1. A description is given of the history of tsetse fly occupation in Southern Rhodesia and the position to-day and the outlook for the future. 2. 2. The previous history of human trypanosomiasis in Southern Rhodesia is summarized. 3. 3. The events leading up to the 1934 medical surveys are related. 4. 4. The discovery of “healthy carrier” cases of human trypanosomiasis at Gowe is described. 5. 5. A description of the natural conditions at Gowe is given. 6. 6. The bearing of the experience at Gowe on the epidemiology and control of the disease in Southern Rhodesia is discussed. 7. 7. Some tentative ideas on protozoal immunity with special reference to human trypanosomiasis are advanced.
[...]
TL;DR: The symptoms produced by chloroform- and formalin-preserved venom of B. quinquestriatus are different from those produced by stings and in specific sera there is no necessary relationship between neutralizing action in vitro and the degree of protection afforded against stings.
Abstract: The symptoms produced by chloroform- and formalin-preserved venom of B. quinquestriatus are different from those produced by stings. The natural sting contains a substance which rapidly paralyses the respiratory centre. The ethal dose of this substance is within wide limits independent of the body weight of the victim. The m.l.d, of the preserved venom is proportional to body weight. A high titre serum (at least twice that of the commercial serum tested) can be produced in rabbits by subjecting them either to injections of formalin-preserved venom or to both injection of preserved venom and stings. In specific sera there is no necessary relationship between neutralizing action in vitro and the degree of protection afforded against stings.
TL;DR: Eosinophilia was more marked in cases with onchocerciasis than in those uninfested, but the association was not sufficiently regular to have much diagnostic significance.
Abstract: 1. 1. A new focus of onchocerciasis is described around Kakamega, in the western part of Kenya Colony. Among fifty-three natives, taken at random, the infestation was found to occur in twenty, i.e. , 38 per cent. 2. 2. Eye-lesions appeared to be common in the district, although it is not yet determined how far these are due to the onchocerciasis. 3. 3. Subcutaneous nodules were relatively uncommon. 4. 4. Eosinophilia was more marked in cases with onchocerciasis (average percentage of eosinophils, 15·2) than in those uninfested (average, 9·7); but the association was not sufficiently regular to have much diagnostic significance.
TL;DR: A series of cases of tropical pyomyositis, successfully treated with M. & B. 693, is described and the possibility of unpleasant, but not dangerous, side-effects following therapy is pointed out.
Abstract: 1. 1. A series of cases of tropical pyomyositis, successfully treated with M. & B. 693, is described. 2. 2. Infections co-incident with the condition are indicated. 3. 3. The possibility of unpleasant, but not dangerous, side-effects following therapy with M. & B. 693 is pointed out.
[...]
TL;DR: It is shown that when positively charged trypanosomes are ingested by a tsetse fly, one reversal of the sign of the charge takes place in the gut of the fly and one reversal in the salivary gland.
Abstract: We have shown that when positively charged trypanosomes are ingested by a tsetse fly, one reversal of the sign of the charge takes place in the gut of the fly and a second reversal in the salivary gland. In the case of negatively charged trypanosomes the only reversal of the sign of the charge occurs in the salivary gland. In both instances the blood trypanosomes produced in rats by the inoculation of infected salivary glands are predominantly positively charged.
TL;DR: Filariasis of the testicle is always bilateral, and both testicles and both inguinal rings should be exposed and treated whenever an operation is done by hydrocele or hernia in a filarial subject.
Abstract: The primary lesion of filariasis is a sterile inflammatory reaction about a dead worm, in a lymphatic vessel. The vessel is occluded and these results an obliterative lymphangitis which causes dilatation, hypertrophy and varicosity, with peripheral lymphstasis. The lymphatics of the testicle are especially vulnerable to such lesions, for they are quite long, have no collaterals, and drain against gravity. Lymphstasis in the testicle is shown by definite clinical signs in the cord, epididymis and testis, which are often the only signs of filariasis demonstrable on physical examination. A patient with early filariasis may show, (1) no demonstrable signs whatever (subclinical state), (2) enlargement of the inguinal and subinguinal (femoral) lymph nodes, (3) thickening and lengthening of the spermatic cord, due to hypertrophy and varicosity of the lymphatics, (4) enlargement and firmness of the epididymis, often with definite nodular thickening, (5) partial or complete obliteration of the sinus epididymis, (6) enlargement of the testis and loss of its elastic firmness, due to oedema, (7) increased fluid in the tunica vaginalis, (8) thickening of the base of the scrotum due to oedema of the ligamentum testis (gubernaculum). A hydrocele is the filarial disorder which most commonly brings the patient to the physician. The lining membrane of the sac can be obliterated by injection treatment or by open operation. Injection treatment is suitable for the small, flaccid, thin-walled sacs, but operation is better for the others. Filariasis of the testicle is always bilateral, and both testicles and both inguinal rings should be exposed and treated whenever an operation is done by hydrocele or hernia in a filarial subject. A transverse suprapubic incision gives adequate exposure for this procedure, and has other advantages.
TL;DR: The lesions met with in monkeys in other organs besides the spleen, suggest that such localizations may be responsible for the varied changes in different organs in human malaria also.
Abstract: A histopathological study of twelve cases of fatal monkey malaria due to infection with P. knowlesi has shown (1) the presence of a vascular mechanism that localizes the parasites in large numbers in the spleen; (2) the presence of a lymphoid reaction in the spleen; and (3) the activation of the reticulo-endothelial system as shown by histiocytic differentiation and active phagocytosis. The severity of the infection appears to be due, not to a failure of the reticulo-endothelial response, but to some other factor which may be the virulence of the parasites for a particular host species. Degenerative swelling of the capillary endothelium with necrosis of the cytoplasmic reticulum around the follicles suggests a toxic factor. Some of the other lesions met with can be explained by the theory of mechanical localization of parasites in the capillaries of the affected part. The lesions met with in monkeys in other organs besides the spleen, suggest that such localizations may be responsible for the varied changes in different organs in human malaria also.
TL;DR: By comparing the healing rates of ulcers, it was found that cod-liver oil dressings with vitamin A by mouth gave better results than those of pooled other treatments, especially for chronic and recurrent ulcers.
Abstract: 1. 1. Tropical ulcer is an important cause of invalidity in parts of the Sudan. 2. 2. Observations directed to etiology and treatment were made on cases in the Nuba Mountains affecting pagan carbohydrate feeders, and Arab carbohydrate feeders with rather more protein in their diet. 3. 3. Half the year, locally, is a dry season, there is a practically total absence of vitamins A, B2 and C. 4. 4. By comparing the healing rates of ulcers, it was found that cod-liver oil dressings with vitamin A by mouth gave better results than those of pooled other treatments, especially for chronic and recurrent ulcers. Vitamin A does not appear to play the major part in the process. 5. 5. It seems that idiopathic tropical ulcer originating in a vesicle or papule is a manifestation of malnutrition. 6. 6. The malnutritional background is one of subnutrition in protein and vitamins A, B2 and C with a relative excess of carbohydrate. 7. 7. Sex, age, race and occupation are factors in as much as they control diet and exposure. 8. 8. Season has an important influence, periods of climatic crisis, coupled with acmes of deficiency-experience and agricultural activity caused two peaks a year, on an incidence curve. 9. 9. Similar peaks occur in pellagra, the common factor being activation of a deficiency state. 10. 10. Recurrence of ulceration has a seasonal character also, two peaks occurring, likewise at periods of climatic crisis coupled with deficiency-experience. 11. 11. Patchiness in the geographical distribution of tropical ulcers is due to variations in dietary coupled with variations in malaria incidence. 12. 12. It seems that a high protein dietary may benefit ulcer cases; added vitamins A and B2 are probably of value also. 13. 13. Signs of malnutrition were more pronounced in old and recurrent ulcer cases than in recent ones, and also in those with slower, as contrasted with those with faster, healing rates. 14. 14. Malaria decreases the healing rate in ulcers, possibly through (a) malarial toxin, (b) increased endogenous protein metabolism, (c) anaemia and (d) splenic dysfunction in its immunological aspect. 15. 15. (a) Cod-liver oil dressing with skim-milk powder added to the diet is recommended as a treatment. (b) Factors in ulcer-diathesis are considered to be deficiency in protein and probably vitamins A, B2 and C; and malarial infection.
TL;DR: The conclusion is drawn, that the endemic typhus is mainly a disease of the non-immunized immigrants, while the indigenous population is assumed to be more or less “silently immunized” in childhood.
Abstract: 1. 1. A short survey is given of the epidemological data on endemic typhus in Palestine as far as they are known at present. The conclusion is drawn, that the endemic typhus is mainly a disease of the non-immunized immigrants, while the indigenous population is assumed to be more or less “silently immunized” in childhood. 2. 2. The clinical picture of endemic typhus in Palestine is fully described and two types of the disease are distinguished. Their characteristic differences may be summarized as follows :-- Type 1. Type 2. Onset … … Moderately severe Very severe Systemic reactions Mild or moderately severe Severe Rush … … Bright colour, small spots, mainly confined to the trunk, short duration Darker colour, large spots, spreading from trunk or limbs and face, long duration Duration of disease 2 to 3 weeks 10 to 12 days Weil-Felix reaction (a) Apparition … 6th to 12th day 12th to 14th day (b) Titre … High Low