An Explanation to the Occurrence of Sporadic Cases of Urinary Schistosomiasis in India
Total Page:16
File Type:pdf, Size:1020Kb
AN EXPLANATION TO THE OCCURRENCE OF SPORADIC CASES OF URINARY SCHISTOSOMIASIS IN INDIA. BY Cor. I. FROIr,ANO DU MRI,LO. (NovA GÓA) Received December 26, 1935. UP-TO-DATE Bilharziosis has not been registered in India as an endemic dis- ease, despite some cases imported from abroad. Stanley Kemp and Gravely'. in an exhaustive study failed to infect the molluscs of Hyderabad and Secunderabad with miracidia of S. hrematobium. I myself' working with S. mansoni imported in our territory by Mozambique troops since 1912, arrived to the following conclusions : (a) no inhabitant of Portuguese India showed any signal of a bilharzic dysentery in the villages occupied from 1912 to 1920 by the African infected troops (clinical and parasitological enquiry), (b) Paclielabra mcesta, Indoplanorbis exustus, Melanodes pyramis collected from various parts of our territory did not show any furcocercaria of S. 'mansoni type. Two types of furcocercariae were however found in Indoplanorbis exustus, but anatomically different from those of S. mansoni 3; (c) we failed to infect with S. mansoni miracidia the above-quoted molluscs. P. mcesta and I. exustus were absolutely indifferent to those miracidia ; M. pyramts, however, showed an evident miracidial attraction. However, no actual penetration was seen, neither any stage of further sporocystic cycle. My conclusions were that, on epidemiological and experimental grounds— at least with the molluscs above quoted—there was no fear of endemisatior, of Intestinal Bilharziosis in Portuguese India. Cautiously, however, I added that - one should not lose the view of a fortuitous and eventual adaptation of Schistosoma to some local molluscs. Negative conclusions were reached in British India, where Seymour Sewell4 states the non-existence of Bullinus and Hypsobia, the universally recognised hosts of S. hrematobium and japonicum and the existence of one single Planorbide, P. exustus, later on classified by Annandale as Indoplanorbis 107 BI a 10N Col. Y. Froilano de Mello exustus. It must not, however, be forgotten that Seymour Sewell found among the Cercc rice indica one resembling morphologically that of S. japonicum whose adult worm was not, unhappily, identified by experimental inocula- tions to suitable animals.' Sporadic cases of Bilharziosis originated in loco have, however, been recorded in India, but as far as I am aware no mollusc has yet been rendered responsible as intermediate host. Leipers thinks that such cases may be produced by some animal schistosome. We will quote his own words " the other ss pp bomfordi, indicurn, spindalis occur in domesticated animals, e.g., horse, sheep, cattle, etc..... It is not at all improbable that they may, like S. bovis, occasionally invade man as incidental infec- tions. Such infections may provide an explanation to the sporadic occurrences'of cases of Bilharziosis in India." I am not aware of any case of human urinary Schistosomiasis definitely related to a Bilharzia of animal origin. Cawston suspected once S. spindalis as the cause of disease in a Zulu School boy. ° S. spindalis is very common in India and no human case has been reported to it. Epidemiological evidence is therefore definitely against the hypothesis of Leiper and Brumpt 8 says rightly : La realité de l'infection de l'homme par Sch. bovis signalée ou admise par divers auteurs reste à démontrer. So, we must find an explanation to the occurrence of such sporadic cases and the present note is written for this purpose. In October 1934, we had here the first and hitherto only case of Schisto- somiasis. Child, 9 years old, son of an African soldier and a Goanese woman hospitalised for cystitis and dysentery and showing in urine and in faces numerous ova of Sch. heematobium. There is no doubt that this case is a true case of Schistosomiasis hcematobia : the clinical symptoms, the good results of emetic treatment and the morpho- logy of the ova fully justify such diagnosis. Occurrence of Sporadic Cases of Urinary Schislosoyniasis in India 109 The measurements of the ova gave the following numbers: (Taken on 96 ova by my pupil Miss Ciriaca Valles, before the treatment.) No. of Length Maximum ova (microns) breadth 4 75 3 7 215 4 88 ,,5a 26 100 1 12 2 2 -6 ï 1 31 35 37 38 4U 50 5b 1T 6 112 3U^ 133 374 1 115 38 1 -1 2 120 s7 5s 1 1 1 3 3 1 1 1 13 125 38 33 35 87 50 60 8 7b 80 1 130 75 1 135 75 1 2 145 15 8 1 4 1 1 2 1 4 1 1 16 150 50 60 62'65 7Ó 72 -T5 8á 1 155 75 3 160 WÓ1 IIQ 2 1 2 1- 6 170 60 -65 75 1ÓO 1 - 6 175 so 70 eo 1 1 2 4 180 60 70 75 110 Col. I. Froilano de Mello (Taken in 100 ova by my pupil Manuel da Veiga Coutinho during treatment, to see whether there was some alteration suggesting the hypothesis of abortion put forward by C. 1ranca9 .) No. of Length Maximum ova (microns) breadth 1 60 30 3 70 a 3 ó 1 2 75-6 3 2_ 2 1 s_ 10 80 35 30 35 4Ó 41 9 85 352 130 435 245 12 6 s _1 . 14 90 3Ó `L6 3Ó 1140 45 12 95 251 33S 2 35 440 25S 6 100 55 :fÓ 35 4Ó 45 13 105 3-6 1111 5 5Ó 1 1 4 1_7^ 8 110 3Ó 35 4ó 55 7ó 9 115 3fl4a455a55 3 120 551 602 3 125 111 6 2 130 351 4b1 3 135 31vr 1 150 65 1 165 45 How was this case originated ? Unless we admit some other mechanism of transmission, we are obliged to accept that some local mollusc was infected and that its cercariae did by their turn infect the child. Occurrence of Sporadic Cases of Urinary Schistosomiasis in India 111 And as the case is a single one we must admit that the responsible mollusc is a very rare one or that the infection occurred only eventually, accidentally in a mollusc showing some affinities to those miracidia. Such an hypothesis of an eventual adaptation is not a rarity in the history of parasitism and even in the life cycle of human Schistosomes, if we consult the literature, valuable information can be collected on this point of view, suggesting the division of the mollusc hosts into habitual or those in whose bodies the bilharzial life cycle always occurs, secondary or those where such life cycle occurs but not so frequently, and eventual or those who having shown an evident miracidial attraction, often followed by penetration, have not, however, given in the hands of the authors a definite final phase of sporocysts and cercariae and are therefore only suspected as able to act as intermediate hosts. On a medical point of view it is much more reasonable to support this last view than to state that probably those rare human bilharzial sporadic cases must be of an animal origin in countries where the suspected animal bilharzioses are widely spread and could naturally produce more human cases. Following these lines we find: Schistosomum heematobium. Habitual hosts.— Bullinus dybowsky, innesi (all classified by Baylis as Bullinus truncatus Andouin, 1826); 10 Physopsis africana, globosa, Isidora (Physopsis) ovoidea," Physopsis conicum, 12 Planorbis dufourii. 13 Secondary hosts.—Limncea natalensis (Porter'2,14) Bullinus broehii (Anderson15 ), Melania nodocincta (Dye 1 e), Melanoides tuberculata (Gopsilll' ,18 ) Eventual hosts.—Limnaea truncatula (Leiper in Raynaud et Léger' 9 , miracidial attraction), Pyrgophysa forksali (id. 19), Planorbis boissyi (id. 19), Planorbis albus (Roubaud iá. 20), I,ymmea limosa (idem with penetration in one specimen20), Bullinus strigosus (Léger 21 mirac. attraction), Pyrgo- physa dunkeri (id. 21), Lymnaea africana (id. 21), Melania tuberculata (id. 21), Physalopsis globosa (idem with penetration Franca9). Schistosomum mansoni. Habitual hosts.—Planorbis (Planorbula) boyssii, Pl. (Planorbis) Pfeifen, Pl. (Planorbina) guadaloupensis, Pl. (Planorbina) centimetralis, Pl. (Planor- bina) antiguensis, Physopsis africana, Bullinus tropicus. Secondary 'hosts.—Melanoides tuberculata (Gopsll 18), Planorbis sp. (closely allied to P. sudanicus Marten) (Dye16) 112 Col. I. Froilano de Mello Eventual hosts.—Planorbis ferrugineus (Lutz22 mirac. attraction with penetration but without the final cercaria phase), Pl. tenagrophylus 22 , some Physa22,19, Pl. cultratus (Iturbe and Gonzalez cit.l"), Ampullaria luteostoma (Iturbe and Gonzalez cit. 19 ), Melanodes pyramis (mir, attraction alone de Mello2). Schistosoma japonicum. Habitual hosts.—Onchomelania (Hypsobia) nosophora, O. formosana, 6 O. hupensis,s (Prososthenia) Blanfordia quadrasi (Tuhangui 23) After these preliminary remarks, we will report the experiments made in our laboratory in order to find out the possible molluscan vector responsible for our case. The snails were collected in the villages where the infected child was living, kept under observation during 48 to 72 hours for examina- tion of any furcocercaria infesting them in natura, and only those recognised free, submitted to further experiments of miracidial attraction and after- wards transferred to a small tank where during 2 months the residuum of the child urine containing living ova was put daily for realising as far as possible a natural mode of infection of those snails. The following are the results of the experiments Pachelabra, mcesta. —No miracidial attraction. No furcocercaria or sporocyst after 2, 3 and 4 months of observation. Indoplanorbis exutus.—Idem. Melanoides tuberculatus. —The child being cured at the time when this snail came to our laboratory, experiments of infection could not unhappily be carried on. It must be emphasised that M. tuberculata has been incriminated by Gopsill as responsible vector both of S. hcinatobium and S. mansoni in the Lower Shire District. One of our Melanoides showed in natura one furcocer- caria not alike to that of S.