Oct 26, 2009 – Malaria, TB, Etc.

Oct 26, 2009 – Malaria, TB, Etc.

HSS4331A – International Health Theory

Tonight

• “Feast or Famine”• 5:30pm-7:30pm, 90 University Pvt, $5– “Feast or Famine is an interactive dinner that aims to

educate participants about food and income disparities worldwide. Upon arrival, participantswill be given a character card that will determine where they are seated, as well as the type of food they receive. Volunteers will be dressed incharacter and engaging with the audience. Special Guest Speaker: Kate Green from USC Canada.”

Smallpox

In 1975, two year old Rahima Banu contracted last known case of naturally-occurring variola major Smallpox. -Wikipedia

The global eradication of smallpox was certified, based on intense verification activities in countries, by a commission of eminent scientists on 9 December 1979 and subsequently endorsed by the World Health Assembly on 8 May 1980-“Resolution WHA33.3”

“You have erased from the calendar of human afflictions one of its greatest. Yours is the comfortable reflection that mankind can never forget that you have lived. Future nations will know by history only that the loathsome smallpox has existed.”

-Thomas Jefferson to Edward Jenner, 1806

Smallpox was eradicated due to:

• 1) no reservoir of the virus existed except in humans;

• 2) nearly all persons infected with smallpox had an obvious, characteristic rash and were infectious for a relatively short period;

• 3) the natural infection conferred lifelong immunity; and

• 4) a safe, effective (even in newborns), and inexpensive vaccine was available that was also highly stable in tropical environments

Global eradication was possible because of…

Herd immunity

International Task Force for Disease Eradication

• Initiated at Carter Center of Emory University in 1988

• Concluded that 7 diseases can be eradicated:– Dracunculiasis (guinea worm)– Poliomyelitis (thought possible by 2000)– Mumps– Rubella– Lymphatic filariasis– Cysticercosis– Measles

Previously on the list:-TB-Leprosy-Rabies-Onchocerciasis-Syphilis

One disease always comes up in conversation….

Malaria• Malaria kills more than 3,000 children under the

age of five each year and more than 1.5 million people total each year– Every 30 seconds, a child dies of malaria

• It infects 400-500 million each year– Largely preventable and treatable

• The majority of these cases occur in sub-Saharan Africa where poverty is the biggest problem facing this epidemic

• Accounts for 10% of all child deaths in the developing world

Malaria in Ottawa

• Often called “ague” in this region• Rampant in early 1800s during canal

construction

Malaria

• Endemic in over 100 countries

www.map.ox.ac.uk

Malaria

• There are four types of human malaria:– Plasmodium falciparum– Plasmodium vivax– Plasmodium malariae– Plasmodium ovale.

(A fifth species –knowlesi- is only found n macaques, but can also infect humans)

Malaria• There are four species of Plasmodium, but we

typically see two types– Falciparum

• The deadliest• Depending on who you believe, it accounts for 50-80% of all

human malaria infections• Accounts for 90% of all malaria deaths

– Vivax• Most frequent cause of recurring malaria• Usually doesn’t kill, but can cause death through an enlarged

spleen

Malaria

• Malaria is not just a disease commonly associated with poverty, but is also a cause of poverty and a major hindrance to economic development

• During the late 19th and early 20th centuries, it was a major factor in the slow economic development of the American southern states.

• The lowest income group in Malawi spends 32% of their income on fighting malaria, versus 4% spent by the highest income group

Malaria• Economic impact on Africa alone is thought to

be $US 12 billion every year. How?•Health care costs•Days of work lost to illness•Days lost in education•Decreased productivity due to brain damage•Loss of investment and tourism income

• In some countries, malaria eats up 40% of all public health resources and accounts for 50% of hospital activity

Malaria cuts economic growth rates by up to 1.3% -WHO

Economic Impact

• In countries where malaria is common, average per capita GDP has risen (between 1965 and 1990) only 0.4% per year, compared to 2.4% per year in other countries– Nature. 2002 Feb

7;415(6872):680-5.

Treatment of Malaria

• Antimalarial drugs (usually based on quinine)• WHO recommends that countries use a

combination of antimalarial medicines to reduce the risk of drug resistance– Resistance of Plasmodium falciparum to

choloroquine, the cheapest and the most used drug is spreading in almost all the endemic countries.

– Resistance to the combination of sulfadoxine-pyrimethamine which was already present in South America and in South-East Asia is now emerging in East Africa.

Counterfeit Malaria Drugs

• Sophisticated counterfeits have been found in several Asian countries such as Cambodia, China, Indonesia, Laos, Thailand, Vietnam and are an important cause of avoidable death in those countries (WHO)

• up to 40% of artesunate based malaria medications are counterfeit (WHO)

DRUG RESISTANCE

Responses to Drug Resistance

• artemisinin-based combination therapy (ACT), since 1990s

Malaria Prevention

• Avoid creating or living near standing water• Mosquito control• Mosquito avoidance– Bed nets– www.buyanet.ca

• Prophylactic drugs

What are development challenges/barriers to implementing the above?

Climate Change

• How does/will climate change affect global malaria?

Malaria distribution, projected for climate change,UNEP

Tuberculosis

TB

• 2 billion people have been exposed• 8-9 million/year become ill from TB• 2 million die per year• In 2004, 15 million had active TB• Biggest infectious killer of women of

reproductive age• Biggest killer of people with AIDS

TB Incidence, 2007

DOTS

• “Directly Observed Therapy, Short Course”

Why do we have DOTS?

Drug Resistance

• MDR-TB (Multidrug Resistant TB) describes strains of tuberculosis that are resistant to at least the two main first-line TB drugs - isoniazid and rifampicin

• XDR-TB, or Extensive Drug Resistant TB (also referred to as Extreme Drug Resistance) is MDR-TB that is also resistant to three or more of the six classes of second-line drugs– In the United States, 4% of MDR-TB cases met the

criteria for XDR-TB

Economic Impact of TB

• Annual loss of $US1.4-1.8 billion of economic growth worldwide due to TB– McGill study by Grimard

and Harling

The Three Great Diseases of Poverty

• HIV/AIDS• Malaria• TB

The Global Fund

• Established in Jan 2002 to fight these three diseases

• Largest global funder of programs to fight malaria and TB

• Provides 20% of all funding to fight HIV/AIDS• Founded as a result of article in 2001 by Jeff

Sachs and Amir Attaran• Funded by G8 nations

Next Week

• First guest lecture by Dr Anne McCarthy!