This document discusses schistosomiasis (bilharzia), a parasitic disease caused by blood flukes of the genus Schistosoma. It outlines the classification of schistosomes, their life cycle involving snail intermediate hosts, symptoms, treatment with praziquantel, and global distribution. It notes that over 250 million people are infected worldwide. The document also discusses how global warming may expand the habitat and transmission of schistosomiasis by increasing temperatures in regions previously too cold for the parasite and snail hosts to survive.

1. Prof Dr Kamran Ashraf
Shifa-ul-haq

2. Biology
Schistosomes are blood flukes and belong to the
• Class Trematode
• Order Digenea
• Family Schistosomatidae

3. Family Schistosomatidae
 Bilharziella
 Ornithobilharzia
 Schistosoma
 Trichobilharzia
Minor Genra
 Austrobilharzia
 Dendrobilharzia
 Gigantobilharzia
 Heterobilharzia
 Microbilharzia
 Schistosomatium

4. Genus Schistosoma
 S mansoni
 S hematobium
 S japonicum
 S intercalatum
 S mekongi
Currently, 21 species of this genus have been recognized

5. Host Range
 Digenetic
 Wide host range in case of S. japonicum
 S. bovis
 S. mattheei
 S. rodhaini

6. Dogs, cats, rodents, pigs, horse
and goats, serve as reservoirs

7. Intermediate Hosts
 S. hematobium and S. intercalatum by Bulinus
 S. mansoni by Biomphalaria
 S. japonicum by Oncomelania
 S. mekongi by Neotricula

8. Right-Bulinus
Left-Oncomelania

10. Flash Video of Life Cycle about
2.30 Seconds
?
?

11. Period of communicability
 Life span 5-10 years( up to 30), so infected human can
excrete eggs up to 10 years.
 An infected snail can release cercariae from several
weeks to 3 months of its life.
 An infected snail can lay eggs 300-3000/day

12. Schistosomiasis
 Bilhaziasis
 Snail Fever
 Urinary Schistosomiasis
 Katayama Fever (Acute Type)
 Swimmer’s Itch or Orientobilharziasis (Orientobilharzia,
Trichobilharzia , Schistosoma spindale )

13.  Theodor Bilharz 1st describe the cause of urinary
Schistosoma.

14.  In ancient Egyptian Papyri symptoms of chronic
haematobium was described as a “Dripping Penis
Disease”
 Schistosoma eggs have been recovered from Egyptian
and Chinese mummies

15. Distribution
 2nd most prevalent parasitic disease in the world, only
behind the Malaria

16.  More than 250 million people are infected (WHO, 2013)
 120 million people are symptomatic.
 Another 700 million people are at risk of infection.

17. Geographic Distribution
 78 countries
 The endemic areas Africa, the Caribbean
South America, East Asia, and the Middle East

19.  200 000 mortality
 1.7-4.5 million DALYs
 DALY (Disability Adjusted Life Years)?
 One lost year of "healthy" life.

21. What, if it’s a huge problem

22. Vaccination
 The administration of radiation-attenuated cercariae
 Antigens from Schistosomules by P-I Lille, France
 Schistosoma paramyosin
 Target the fecundity of the female Schistosomes

24. Treatment
 Praziquantel
 Somehow Artemether

25.  At least 243 million people required treatment for
Schistosomiasis in 2011 (WHO)

26.  The number of people reported to have been treated
for Schistosomiasis in 2011 was 28.1 million
 Reasons
 Shortage of medicine
 High cost of Praziquantel
 No other proven alternative
 Patent competition

28. Concluding
 More than 250 million affected
 700 million at risk
 No vaccine possibility in near future
 243 million required treatment, but only 28 million
got it
 But the problem not halted here

30. Global Warming
 An Average increase in the temperature of the
atmosphere which can contribute to changes in global
climate patterns.

31. How Global Warming Works?

32. Causes of Global Warming
 Burning of Fossil Fuels (coal/crude oil)

33. Causes of Global Warming
 Population Increase

34. Causes of Global Warming
 Deforestation

35. Causes of Global Warming
 Transportation- Fuels (LPG, Kerosine, Fuel, Jet Oil)

36. Causes of Global Warming
 Industrial Process, manufacturing of steel, cement

37. Causes of Global Warming
 Agriculture and Farming
 Methane is 20% responsible for global warming and
2/3 of methane is produced by animals
 Ruminants produce 80 million metric tons of methane
annually
 Methane is more potent green house gas than co2

39.  Interestingly Ciliate Protozoa are more responsible for
methane production (Isotricha, Eudiplodinium,
Epidinium + Entodinium)

40. Causes of Global Warming
 Waste Management
 Landfills are also major source of methane

41. Causes of Global Warming
 Use of Natural Gas for Cooking

42. Environmental and Human
Effects of Global Warming
 Increase in average temperature : More extreme heat
waves, less cold spell of winter
 Increase in frequency of extreme events: tornados,
floods, heat waves, snow fall
 Rising in temperature and variable precipitation:
decrease production of staple food: Increase in
Malnutrition

43. Environmental and Human
Effects of Global Warming
 Population Displacement:
 Flooding
 Sea level rising
 More than half of the world's population is now living
within 60km of the sea

44. Environmental and Human
Effects of Global Warming
• UV Exposure
• Skin Cancer
• Premature Aging
• Cataracts
• Suppression of Immunity

45. Environmental and Human
Effects of Global Warming
 Climate-Sensitive Diseases

46.  Development of cold-blooded animals is positively
related to temperature.
 Development will arrest when temp. drops below
acritical threshold
 Lowest developing temp. or “biological zero”
 The higher the temperature, the higher
 the possibility that the host snail will shed cercariae of
S. japonicum

47.  According to available temperature data for 1960 and
2000, the median January temperature, averaged
across the 193 observing stations in China, increased
by 0.9 C.
 The mean temperature will continue to rise; indeed at
an accelerated pace with predicted increases by 2030
and 2050 of 1.7 and 2.2 C, respectively

48.  Biologic model and experiments identified a
temperature threshold of 15.4 C for development of
Schistosoma
japonicum
within
Oncomelania
hupensis, and a temperature of 5.8 C at which half the
snail sample investigated was In hibernation
 Historical data suggest that the geographic range of O.
hupensis is cold tolerant and restricted by the mean
January temperature of 0 C
 So, the increasing average temperatures associated
with global warming are hypothesized to increase the
ranges of O. hupensis habitat

49.  At the same time, longer seasonal periods of mean
temperatures > 15.4 C (the minimum temperature
needed for parasite development) mean that the
“accumulated degree-days” necessary for parasite
development and transmission will
progressively more regions than before
occur
in

52.  Ultimately, as global warming progresses, more areas
currently deemed as marginal for snail and
schistosome habitat are expected to become
recognized transmission zones