Download Tropical Diseases

Tropical Diseases
• Tropical diseases encompass all
diseases that occur solely, or
principally, in the tropics. In practice,
the term is often taken to refer to
infectious diseases that thrive in hot,
humid conditions, such as malaria,,
schistosomiasis, and dengue.
Neglected Tropical diseases
• The people who are most affected by
these diseases are often the poorest
populations, living in remote, rural areas,
urban slums or conflict zones. Neglected
tropical diseases persist under conditions
of poverty and are concentrated almost
exclusively in impoverished populations in
the developing world.
Climate change integrated
framework
Why climate change impacts tropical diseases?
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Elevated temperature
Shortening the develop cycle of pathogen
Hot weather + CO2 = biomass, shelter
Enhancement of bacterial survivals
Increased rainfall
Survival and transmission of water-borne diseases
Breeding sites
Drought and flood
Water contaminated by fecal and rat urine
Lack of food and fresh water, physical damage,
overcrowding
Malaria
• Malaria is caused by a one-celled parasite.
Female mosquitoes pick up the parasite
from infected people when they bite to
obtain blood needed to nurture their eggs.
Inside the mosquito the parasites develop
and reproduce. When the mosquito bites
again, the parasites mix with its saliva and
pass into the blood of the person being
bitten.
Symptoms
• Malaria parasites multiply rapidly in the
liver and then in red blood cells of the
infected person. One to two weeks after a
person is infected the first symptoms of
malaria appear: usually fever, headache,
chills and vomiting. If not treated promptly
with effective medicines, malaria can kill
by infecting and destroying red blood cells
and by clogging the capillaries that carry
blood to the brain or other vital organs.
Dengue
• Dengue is transmitted by the bite of an Aedes
mosquito infected with any one of the four
dengue viruses. Symptoms appear in 3–14 days
(average 4–7 days) after the infective bite.
Dengue fever is a severe, flu-like illness that
affects infants, young children and adults. There
is no specific treatment for dengue fever.
Dengue haemorrhagic fever is a potentially
lethal complication but early clinical diagnosis
and careful clinical management by experienced
physicians and nurses often save lives.
Dengue (cont)
• More than 70% of the disease burden is in
South-East Asia and the Western Pacific area.
Africa and the Eastern Mediterranean are much
less affected. In Latin America and the
Caribbean, the incidence and severity of disease
are increasing rapidly. Increase in international
air travel is facilitating the rapid global
movement of dengue viruses. This increases the
risk of dengue haemorrhagic fever epidemics by
introducing new dengue viruses into susceptible
populations.
Leprosy
• Leprosy is a chronic disease
caused by a bacillus,
Mycobacterium leprae.
Official figures show that
more than 213 000 people
mainly in Asia and Africa are
infected, with approximately
249 000 new cases reported
in 2008.
• Leprosy is not highly
infectious. It is transmitted
via droplets, from the nose
and mouth, during close and
frequent contacts with
untreated cases.
Schistosomiasis
• Schistosomiasis is a chronic
disease caused by parasitic
worms.
• An estimated 700 million
people worldwide may be at
risk of infection as their
agricultural, domestic and
recreational activities expose
them to infested water.
• More than 207 million people
are infected worldwide – most
live in poor communities
without access to safe drinking
water and adequate sanitation.
Cholera
• Cholera is an acute diarrhoeal disease that can kill
within hours if left untreated.
• There are an estimated 3–5 million cholera cases
and 100 000–120 000 deaths due to cholera every
year.
• Up to 80% of cases can be successfully treated with
oral rehydration salts.
• Provision of safe water and sanitation is critical in
reducing the impact of cholera and other waterborne
diseases.
• Oral cholera vaccines are considered an additional
means to control cholera, but should not replace
conventional control measures.
Yellow fever
• Yellow fever is an acute viral haemorrhagic
disease transmitted by infected mosquitoes.
The "yellow" in the name refers to the
jaundice that affects some patients.
• Up to 50% of severely affected persons
without treatment will die from yellow fever.
• There are an estimated 200 000 cases of
yellow fever, causing 30 000 deaths,
worldwide each year.
• The virus is endemic in tropical areas of
Africa and Latin America, with a combined
population of over 900 million people.
The Global Outbreak Alert and
Response Network
• Objectives
• The Global Outbreak Alert and
Response Network contributes
towards global health security
by:
• combating the international
spread of outbreaks
• ensuring that appropriate
technical assistance reaches
affected states rapidly
• contributing to long-term
epidemic preparedness and
capacity building.
• http://www.who.int/csr/outbreak
network/en/