Biological Disasters

Presented by;

Dr. Naveen Kumar,S

I Ph.D., Dept of AGB.

Overview

1. Definition

2. Biological Agents as Causes of Mass destruction

3. Sources of Biological Agents

4. Methods of dissemination/delivery

5. Types of Biological Agents

6. History: Major Events across the Globe

7. Present status and context

8. Impact of Biological disasters

9. Prevention of Biological disasters

Definition

• Biological disasters of natural origin are largely the result

of the entry of a virulent organism into a congregation

of susceptible people living in a manner suited to the

spread of the infection.

• Anthrax - spore dispersal in the air

• Small pox - aerosols

• Typhus & plague - lice, fleas, rodents, etc.

• Epidemic spreads locally and dies down if the contagion is

localised

• diseases have spread widely, even across national

boundaries.

• Disasters occurred - environmental factors - conducive

• Black Death occurred - increase in no. of rats

• Cholera attained a pandemic form - causative agent

entered urban areas which had inadequate sanitation

facilities.

• Similarly, post WW I, the movement of population -

Spanish influenza virus.

Biological Agents as Causes of

mass destruction

• Highly virulent agents have the potential of infecting

large numbers - infectious chains.

• The potential of some infectious agents is nearly as

great as that of nuclear weapons

• Weapon of Mass Destruction (WMD): Nuclear, Biological

and Chemical (NBC).

TRENDS FAVORING BIOLOGICAL WEAPONS

• Low cost and widespread availability

• More efficient in terms of coverage /Kg of payload

• Advances in biotechnology have made production easy

• Agents are largely natural pathogens and simulate existing

diseases.

• Have an unmatched destructive potential

• Technology for dispersing biological agents -

sophisticated.

• The lag time between infection and appearance of

symptoms is longer than with chemical exposures.

• Lethal biological agents can be produced easily and

cheaply.

Sources of Biological Agents

• Any human, animal or plant pathogen can cause an

epidemic or biological weapon.

• The deliberate intention/action to cause harm -

biological attack.

• Incident in the USA where members of a religious cult

caused gastroenteritis by the use of Salmonella

typhimurium (Common natural pathogen)

Methods of dissemination/delivery

• Aerosols - biological agents are dispersed into the air,

forming a fine mist that may drift for miles.

• Animals – fleas, mice, flies, mosquitoes, and livestock.

• Food and water contamination - some pathogenic

organisms and toxins may persist in food and water

supplies.

• Person-to-person : Smallpox, Plague, and the Lassa

viruses.

Types of Biological Agents

• There are three categories of biological agents potential

enough to cause mass casualties (Center for Disease

Control & Prevention).

• Category A, B & C

• Those in category A have the greatest potential for fear

and disruption and most significant public health

impacts.

CATEGORY A

• Easily disseminated or transmitted person-to-person

• High mortality

• Require special action for public health preparedness

• Viruses: Variola major (smallpox), Filo viruses (Ebola,

Marburg), Arenaviruses (Lassa, Junin)

• Bacteria: Bacillus anthracis (anthrax), Yersinia pestis

(plague), Francisella tularensis (tularemia)

• Toxins: Clostridium botulinum toxin (botulism)

CATEGORY B

• Moderately easy to disseminate

• Moderate morbidity and low mortality

• Require improved diagnostic capacity & enhanced surveillance

• Viruses: Alphaviruses

• Bacteria: Coxiella burnetii (Q fever), Brucella spp. (brucellosis),

Burkholderia mallei (glanders)

• Toxins: Rinus communis (caster beans) ricin toxin, Clostridium

perfringens episolon toxin, Staphylococcus enterotoxin B

• Food/waterborne pathogens: Salmonella spp., Vibrio cholerae,

E. coli O157:H7, Shigella dysenteriae, Cryptosporidium parvum,

etc.

CATEGORY C

• Viruses: Nipah, hantaviruses, tick borne hemorrhagic fever

viruses, tick borne encephalitis viruses, yellow fever

• Bacteria: Multi-drug resistant Mycobacterium tuberculosis

Characteristics of BW agents

Source: Medical Management of Biological Casualties handbook, Sixth edition, April 2005;

USAMRIID, Fort Detrick Frederick, Maryland

• Certain characteristics need to be present for an

organism - potential biological agent for warfare or

terrorist attack.

• Anthrax, smallpox, plague, tularemia, brucellosis and

botulinism toxin - leaders in the field.

• Use of agents that target livestock and crops could be as

devastating as human pathogens - probable economic

impact on the community.

History: Major Events across the

Globe

• Biological warfare has a long history of mass destruction

- epidemic and pandemic diseases.

• Limited biological warfare is reported to have been

carried out by Japan during World War-II

• Mycotoxins have been reported to be used in

Afghanisthan

• the Red Indians in North America were given the

smallpox infected blankets

• 2001, the USA experienced biological attacks involving

the intentional distribution of bacillus anthracis spores

through the postal system.

Documented Intentional Use of Biologicals

• Japan used plague bacilli in China during 1932-1945

causing 260,000 deaths

• Dispersal of anthrax spores due to accident in production

unit in USSR (Sverdlovsk) caused 68 deaths in 1979

• In 1984, Osho followers used Salmonella typhimurium in

salad in a restaurant in Oregaon, USA leading to 751

cases

• Shigella dysenteriae Type 2 employed in Texas, USA in

1996

• Anthrax spores through postal envelopes in USA in Oct-

Nov 2001 leading to 22 cases and 5 deaths

Present status and context

• India accorded significant priority - control & elimination

of diseases - major public health burden.

• Eradication of smallpox in 1975 that accounted for

majority of deaths in 18th and 19th centuries.

• Malaria is another major public health problem - fall in

economic production with over 75 million cases

annually in the early 1950s, which has now been

successfully brought down to two million cases annually

• plague, which had assumed epidemic proportions in

the early to mid 19 th and 20th centuries, has

nearly been eliminated.

• Plague outbreak in Surat (1994) with over 1,000

suspected cases and 52 deaths - widespread panic and

mass exodus of people

• SARS outbreak in 2003 caught the attention of the

world - spread of a disease from a single hospital case

to a global pandemic in less than three months.

• Though India reported only three, the panic created by

the media was unprecedented.

• Similarly, the outbreak of avian influenza among poultry

in Nandurbar and Jalgaon districts of Maharashtra and

adjoining districts of Gujarat and Madhya Pradesh

(2006) saw the poultry industry plummet.

• A still greater threat - possibility of avian influenza

(H5N1) to become a pandemic virus that may kill

millions.

• The 1918 influenza pandemic killed an estimated 7

million people in India.

• Slow, evolving epidemics such as HIV/AIDS - socio-

economic disruption

• Emerging and reemerging diseases, notably SARS,

avian influenza, Nipah virus, leptospirosis, dengue,

Chikungunya and Rickettsial, are also posing serious

threats.

• Among the eight to ten globally recognised, most

harmful Trans-boundary Animal Diseases five are

existing in the country, e.g., FMD, PPR, Newcastle

disease, hog cholera and bluetongue.

• India has been successful recently in eradicating

rinderpest

• Highly Pathogenic Avian Influenza (HPAI) (bird flu) has

already invaded the country on two occasions in

successive years 2006 and 2007.

• Through timely intervention - control the potential for a

human pandemic

Impact of Biological Disasters

• Bioweapons - ‘the poor man’s nuclear bomb’

• Large scale operation may cost $ 2,000 per sq. km with

conventional weapons,

• $ 800 with nuclear weapons,

• $ 600 with nerve gas weapons and

• $ 1 with biological weapons.

• Dispersal experiments have been attempted using non-

pathogenic Bacillus globigii

• An attack on the New York subway system would kill at

least 10,000 people.

• WHO studies show that a 50 kg dispersal on a population

of 500,000 would result in up to 95,000 fatalities.

• In case of smallpox, the emergence of secondary cases

at the rate of 10 times the number of primarily.

• Inevitably, epidemics would break out and social chaos

would ensue.

• The economic impact of BT would be a major burden

• Use of Bacillus anthracis would cause losses of $26.2

billion per 100,000 persons exposed, while a less lethal

pathogen, e.g., Brucella suis would cause $477.7 million.

• A BT attack on agriculture can cause as much economic

loss as an attack on human beings.

• The spread of the Parthenium hysterophorus weed - late

1950s along with imported wheat, affected the yield of

fodder crops and became a crop pest

Prevention of Biological Disasters

a) Vulnerability Analysis and Risk Assessment

b) Environmental Management

i. Water supply

ii. Personal hygiene

iii. Vector control

iv. Burial/disposal of the dead

c) Prevention of Post-disaster Epidemics

d) Integrated Disease Surveillance Systems

e) Pharmaceutical Interventions: Chemoprophylaxis,

Immunisation and Other Preventive Measures

f) Non-pharmaceutical Interventions

i. Social Distancing Measures

ii. Disease Containment by Isolation and Quarantine

Methodologies

g) Biosafety and Biosecurity Measures

Thank You