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.
7. Intermediate Hosts
S. hematobium and S. intercalatum by Bulinus
S. mansoni by Biomphalaria
S. japonicum by Oncomelania
S. mekongi by Neotricula
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
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
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
18.
19. 200 000 mortality
1.7-4.5 million DALYs
DALY (Disability Adjusted Life Years)?
One lost year of "healthy" life.
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
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
27.
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
29.
30. Global Warming
An Average increase in the temperature of the
atmosphere which can contribute to changes in global
climate patterns.
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
38.
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
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
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
50.
51.
52. Ultimately, as global warming progresses, more areas
currently deemed as marginal for snail and
schistosome habitat are expected to become
recognized transmission zones