The human blood fluke.
- Date:
- [1952]
- Videos
About this work
Description
Discusses the epidemiology of schistosomiasis and describes the life-cycle of schistosoma mansoni, its laboratory culture and its chemotherapy in experimentally infected mice. The laboratory culture of the water snail vector Australorbis glabratus is also shown, together with the methods for extracting miracidia from infected faeces, infecting snails, and infecting laboratory mice with cercariae obtained from the snails. Animated diagrams are used to show how the schistosome eggs pass into the faeces; the stages of development within the snail vector; the cercariae penetrating the skin of the host, and their subsequent passage to the liver and circulatory system. 8 segments.
Publication/Creation
[U.K.] : [Wellcome Foundation Film Unit], [1952]
Physical description
1 encoded moving image (27.50 min.) : sound, color
Duration
00:27:50
Copyright note
Wellcome Trust, 1952 & 2008
Terms of use
Some restrictions
CC-BY-NC
Language note
In English
Creator/production credits
Wellcome Foundation Film Unit with Dr. Owen Standen and the Department of Helminthology, Wellcome Laboratories of Tropical Medicine, London; producer and director, Florence Anthony; photographer, Douglas Fisher
Contents
Segment 1 Opening credits followed by a shot of a paired male and female human blood fluke mansoni. The fluke is seen in the portal vein of a hamster and in the mesenteric veins, where the eggs of the female are laid and passed out with the faeces. Commentary and diagrams explain the effect of schistosoma in humans. Early recordings of schistosoma by the Egyptians are noted along with subsequent discovery of different species in the early twentieth century. Animated map diagrams show the geographical occurrence of the various species. Time start: 00:00:00:00 Time end: 00:03:36:06 Length: 00:03:36:06
Segment 2 The various species of freshwater snails, in which the flukes spend a part of their life-cycle, are shown. A variety of literature, produced to educate natives into lifestyle changes to prevent the sperad of the disease, is shown. A number of cures are shown, including tartar emetic, the drug Stibophen, Triostam and Nilodin. Time start: 00:03:36:06 Time end: 00:06:05:09 Length: 00:02:29:02
Segment 3 Title: 'The Life Cycle of schistosoma mansoni'. Animated diagrams show how the schistosoma invade the body. Magnified and microscopic footage is shown of the parasite and its physiology is described in much depth including the hatching of the parasitic egg. We see how the parasite penetrates the snail's body and multiplies. The multiplication is shown in an animated diagram. Time start: 00:06:05:09 Time end: 00:12:24:05 Length: 00:06:18:27
Segment 4 The life of the first stage of the cercariae is shown; an animated diagram illustrates how it invades a mouse's skin and how, as schistosomula, it travels through the human body into the liver. The sexually mature worm can reproduce and the whole cycle begins again. Title: 'End of Part One'. Time start: 00:12:24:05 Time end: 00:15:41:12 Length: 00:03:17:04
Segment 5 Title: 'The Human Blood Fluke Part Two: Experimental schistosomiasis. Laboratory Maintenance of schistosoma mansoni'. White mice, rhesus monkeys and golden hamsters can be used to take a schistosomiasis infection. The South American snail is also used to take the infection and snail colonies are set up in tanks. These are shown in depth. We see newborn snails and the complicated process of producing calcium alginate for the snails to eat. We see the young snails eating a sheet of this food, then progressing to eating lettuce when a few months old. At 12 weeks old they are deemed ready for infection. Time start: 00:15:41:12 Time end: 00:19:53:08 Length: 00:04:11:25
Segment 6 Title: 'Infection of Snails'. Eggs are taken from the stools of infected mice. The stools are ground to a paste, filtered into a solution and left to settle - the schistosoma eggs sink to the bottom of a glass, forming miracidia. The snails are then infected with the miracidia and allowed to incubate until the cercariae are produced. Time start: 00:19:53:08 Time end: 00:22:26:24 Length: 00:02:33:16
Segment 7 Title: 'Infection of Mice'. White mice are shown being infected individually in small glass pots. After 50 days the mice faeces are examined under the microscope for signs of the infection. Title: 'Chemotherapy'. At autopsy, the mesenteric veins of the infected mouse are shown, as are the enlarged liver and spleen. Infected mice are shown being treated with Nilodin twice a day for 5 days. A week later they are killed and dissected in order to see how the treated mice differ from those left untreated. Time start: 00:22:26:24 Time end: 00:27:50:10 Length: 00:05:23:15
Segment 8 The change in the worms after being treated with Nilodin is described and illustrated with diagrams. Prolonged treatment of the drug is recommended to fully remove the presence of the worms from the body. If drugs are stopped too soon, relapse rapidly occurs. The most efficient drug therapies are covered. End titles. Time start: 00:27:50:10 Time end: 00:31:01:24 Length: 00:03:11:13