SAR HS 325 Lecture Notes - Lecture 6: New International Version, Encephalitis, Bushmeat
1 May 2018
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NIPAH (NiV), SARS, EBOLA (EVD)
Nipah Virus (NiV)
• Associated with encephalitis (inflammation of the brain)
• Incubation period of 5 to 14 days
• First presents within 3-14 days
• Symptoms: fever/headache followed by drowsiness/disorientation/mental confusion
o Can progress to a coma within 24-48 hours
• CFR: 40%
o During the NiV outbreak in 1998-1999, 265 patients were infected with the virus
and about 40% of those who entered hospitals with symptoms died
• Reservoir Hosts of NiV – fruit bats or flying foxes
o Important to remember that reservoir hosts do not show symptoms but instead just
“house” the virus
o They feed mainly on fruits such as mangoes/bananas/figs
o They roost in large colonies in tall trees/caves
o They fly and feed at night
o Virus is held in their saliva and urine
o Pigs are the immediate spillover host
o Range – can fly across the world
Emergence: Malaysian Pig Farmers (1998)
• Bats moved into cultivated fruit orchards focused within piggeries
• Pigs became infected, most likely through ingesting saliva-infected fruit droppings
• Eventually the pig farmers themselves became infected
• Factors in Emergence:
o 1997/1998 – Indonesia started a slash and burn deforestation
▪ This pushed bats into Malaysia because they no longer had homes
o 1997/1998 – the El Nino drought
▪ Pushed bats to find food and water
o These events reduced flowering/fruiting forest trees for fruit bats, resulting in
encroachment of fruit bats into the cultivated fruit orchard
▪ Powered the transition between the reservoir hosts to the immediate
spillover host (pigs) to humans
• Emergence Results
o Mass pig cull
o January 1999 – 2.4 million pigs and 1800 pig farms are destroyed
o July 21, 1999 – 1.1 million pigs and 956 farms are destroyed
o The cull was hampered by farmers who felt inadequately compromised by the
government
▪ This resulted in pig farmers smuggling pics from infected farms to be sold
on the black market
Emergence: Bangladesh (2001)
• Only resulted in 13 cases
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• Primary Exposure –
o A result of direct and indirect contact with places where fruit bats roost and feed
o Bat contamination of food products (eating and urinating into these pots)
▪ Collection pots for date palm sap were being poured into communal pots
to be sold
• Different than the Malaysian outbreak
o Humans were being infected directly from the reservoir hosts
▪ Why?
▪ There are no pig farms in Bangladesh (because pork is not consumed for
religious reasons)
• Solution: communities began covering buckets in order to prevent bats from perching on
top of them and feeding/urinating into them
Public Health Triumph
• Developing public health interventions do not have to be ingenious scientific discoveries
o The best public health interventions are typically the most boring
• Important to understand that public health interventions will not be the same between
countries
o As seen with Malaysia and Bangladesh, it took two different methods to eliminate
the virus and protect people against it
SARS: Severe Acute Respiratory Syndrome
• An airborne virus
• Transmission: mostly through face-to-face contact but may also be spread on
contaminated objects
• Incubation Period: 2-10 days
• Symptoms: flu-like (ex: fever, headache, diarrhea, muscle aches)
• Respiratory Phase: 2-7 days after early symptoms
o Typically lasts 1 week
o Dry/nonproductive cough/labored breathing
o In severe cases, an increasing lack of oxygen in the blood can be fatal
• Recovery Phase: begins 14-18 days after onset of symptoms
o Important to seek treatment as soon as symptoms appear
• Animal Reservoir
o Palm Civets
▪ Wet markets allowed the horseshoe bats to come in contact with the palm
civet, who passed SARS to humans
▪ Wet Market – the animals being sold are either live or butchered live
Emergence: Hong Kong
• Believed to be the source of the spread of SARS to other countries
• The hardest hit during the worldwide epidemic
• CFR: 17%
SARS Timeline
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Public health triumph: developing public health interventions do not have to be ingenious scientific discoveries, the best public health interventions are typically the most boring. Important to understand that public health interventions will not be the same between countries: as seen with malaysia and bangladesh, it took two different methods to eliminate the virus and protect people against it. Sars: severe acute respiratory syndrome: an airborne virus, transmission: mostly through face-to-face contact but may also be spread on contaminated objects. Emergence: hong kong: believed to be the source of the spread of sars to other countries, the hardest hit during the worldwide epidemic, cfr: 17% Infection of family members/caregivers: commonly occurs with close contact with a severely ill patient during care at home or in the hospital, 2. Infection via contact with dead bodies: commonly occurs during preparation for and during burial, 3.
