Greg Doyon

Food:

Mad Cow Disease (vCJD)

Vector:

Malaria

Water:

Cryptosporidium

Aerosol:

Tuberculosis

Mad Cow Disease or variant Creutzfeldt-Jakob Disease overview:

Mad Cow Disease is to cows as vCJD is to humans.

Mad Cow Disease = Bovine Spongiform Encephalopathy

BSE is a degenerative brain disease in cows that comes from a prion aka misfolded protein

These prions infect proteins within the brain to cause microscopic “holes” in the brain

Creutzfeldt-Jakob Disease (CJD) Is a degenerative brain disease that affects

humans aged 45-75, but 60-65 is the most vulnerable population

Creates a sponge-like texture in the brain variant Creutzfeldt-Jakob Disease (vCJD) Comes from eating beef tainted with BSE or Mad

Cow Disease

Degenerative brain disease that is known to affect people in their 20’s.

Origins: 2 Hypotheses:

1st: BSE comes from the disease Scrapie▪ Scrapie affects the lymph nodes of sheep and is also

based on Prions.

▪ Cattle ate contaminated sheep with Scrapie

2nd: BSE comes from a single cow.▪ A sporadic case of BSE forms in a cow and is spread

through the feed.

▪ Most recent evidence suggest this is the most possible cause

Genetic Factors affecting humans:

PRNP

▪ Gene that encodes the prion protein

The PRNP locus was strongly associated with risk across several markers

▪ Basically the position of this gene on a chromosome

The polymorphic codon 129 of PRNP was the main genetic risk factor for vCJD

(Mead, S. et. al, 2009)

Hard question to answer. Practices

If BSE originated in a sporadic fashion than it seems as though this could have happened anywhere.

Possibly England was using a different antibiotic than other modern countries.▪ Recycling of antibiotic meat or even just recycling of

cattle

▪ Possibly a new mutation occurred?

Ireland had a significantly lower number of BSE cases compared to England 1,353 vs. 183,841. Ireland’s primary method to feed cattle is

predominately grass based In U.S.A., we feed our cattle with Soybean Meal

and Cotton Seed Meal Ban on feeding cattle with remains from other

animals Much less expensive 3 cattle had BSE, at least 1 came from Canada

Farms are in rural parts of the country, however contaminated meat is being shipped through out England.

Preference to live in city away from farms

Mosquito-borne infectious disease Caused by eukaryotic protists Prevalent in Equatorial regions of the world

Thrives in warm rainy areas

Environment allows mosquitoes to breed constantly

Causes headache, fever, coma, and death

Malaria was very prevalent in late 18th century England: Deaths per 1,000 per year

18th

Century Essex, England

18th

Century Essex, England

20th

Century Garki, Nigeria

Age NonMarsh Marsh Savannah

5 44 95.3 154

6-10 6.3 9.4 15

11-15 6.8 10.8 10

16-20 8.4 12.7 6

http://www.cdc.gov/ncidod/eid/vol6no1/reiter.h

tm

Question: What brought Malaria to the marshes of England in 17th and 18th Century?

Answer: Climate change

The climate had naturally become warmer as it is constantly going through waves of warming and cooling

Why is this important now and is it a threat? What other threats of Malaria exist as well?

In 1975 WHO, declared Europe “Free of Malaria”

Mass mosquito spraying, England as well

In 1977, 83% of the world was Malaria Free, with only Sub-Saharan Africa being affected.

As time went on, Malaria started to reappear first in South America, tropical Asia, and some Mediterranean countries.

Some theories of the resurgence of Malaria include:

Deterioration of Vector control

Urbanization

Clearance of forests

Population increase

Resistance to insecticide

Climate change

Yes, with the resurgence of Malaria and increasing global temperatures, the marshes of Southern England could again be stricken with Malaria

“The researchers have calculated that if global warming continues at its current rate, some of these same areas could once again become breeding centres for malaria for up to four months each year by the end of this century.”

http://news.bbc.co.uk/2/hi/health/1775427.stm “UK faces summers of malaria” (2002)

If Malaria does come back to England, likely to occur in: Southern Marshes

Northern England will be safer due to cooler temperatures

No imminent outbreak about to occur, however there is a very strong possibility that it can return to the English Marshes

Best way to control: IPM

A protozoan parasite found in contaminated water

Can colonize and reproduce in the intestines of humans and other vertebrates

Develops into an oocyst which is extremely hard to destroy

Spread through the fecal-oral route Main symptom is diarrhea

Can be fatal in immunocompromised people such as AIDS patients

http://upload.wikimedia.org/wikipedia/commons/7/73/Cryptosporidio

sis_01.png

Crypto has been the most prevalent infectious water-borne disease in the past 10 years in England. (Jones, M. et al, 2006)

In England and Wales between 1992 – 2003, Crypto was responsible for 70% of all water-borne outbreaks (Smith, A. et al, 2006)

(Smith, A. et al, 2006)

Swimming Pools contaminated with Crypto:

Regular treatment should reduce risk

Nearly impossible to prevent point-source infection

Crypto oocysts can been introduced by accidental fecal release by young children

Parents should prevent children with gastrointestinal distress from swimming in pools

(Smith, A. et al, 2006)

August 2003

Outbreak of Crypto in children following a visit to an “adventure park” in SW Rural England

Several activities included water, water rides, and contact with farm animals

Took water samples at various locations

Took stool samples of the farm animals▪ (jones, M et al, 2006)

91 children got sick Median age was 6 94% reported diarrhea 64% vomiting 62% abdominal pains 51% nausea

23/27 water samples contained various amounts of Cryptosporidium

Due to failure of communication between Park and Researchers, they were unable to test animal stool samples

Recirculation of contaminated water Poor filtration and disinfection Also, nearly all the children did not show

symptoms until 2-6 days following visit. Due to incubation time, children could easily

affect any family members or friends without knowing. i.e. Swimming Pools

Adventure park was in a rural area Residential pools are more likely to be

outside of the city, in more rural and suburban areas.

People in rural areas are more likely to have contact with animal feces, farms

Rural parts are more likely to be affected with Cryptosporidium

Potentially lethal infectious disease Caused by bacteria, attacks the lungs Spread through air when people with an

active infections sneeze, cough, or transmit saliva through air

Most infections are asymptomatic and are latent

1 in 10 will progress to active disease and >50% will die if left untreated

Was the biggest killer in UK in 19th century

http://en.wikipedia.org/wiki/File:Tuberculos

is_symptoms.svg

2005, TB cases rose 10.8% from previous year in England

London recorded 3,479 cases, up from 3,129 in 2004

The highest proportion of cases - 38% - were reported among people from an Indian, Pakistani and Bangladeshi ethnic background.

Levels of TB in the UK-born population have remained stable

Foreign born population accounted for 5,310 cases in England in 2005

However on 22% arrived in England in past 2 years

This suggests a combination of:

Latent infections

New infections acquired from infected person in England

Travel to other countries where TB is common

Extremely high amounts of TB in countries a foreign-born UK citizen would travel too.

India, Bangladesh, Many African countries as well

WHO: South East Asia accounts for 35% of World’s TB rate

WHO: Africa accounts for 30% of World’s TB rate

According to 2001 UK Census:

1,053,411 Britons had full Indian ethnicity.

99.3% resided in England

491,300 resided in London

1,148,738 Britons categorized themselves as Black British

1,100,000 resided in London

This means that the chances of someone from England traveling to a region where TB is prevalent is extremely high

Many of foreign born people are living in urban-London, making the urban region extremely susceptible to TB

Prevention and education for those traveling to high TB areas is key

Questions?