BIOTERRORISM AND PUBLIC HEALTH

What is Bioterrorism?• Terrorism: is the deliberate use of, or threatened use of,

violence to achieve political, religious or ideological objectives.

• Bioterrorism: is the use of infective organisms to achieve this goal.

History of Bioterrorism• Bioterrorism is not new. Examples include:

• 6th century BC--Assyrians used rye ergot to poison the wells of its enemies

• 400 BC--Scythian archers dipped arrows in decomposing bodies or manure to cause wound infections

• 15th-18th centuries--smallpox-laden clothing and blankets were given to enemies to induce outbreaks

Modern Day Bioterrorism 1st ½ of the 20th century • Many industrialized nations, including the US, had

offensive biological weapons programs• Biological Weapons Convention (1972)—treaty developed

by international community preventing stockpiling of biological agents and research into offensive biological weapons • Despite being signatories of treaty, several countries, particularly

Iraq and the Soviet Union, continued active biological weapons production

Modern Day Bioterrorism 90’s • Concern for bioterrorism mounted in the 1990’s…

• 1991 dissolution of former USSR led to a mass exodus of bioweapons scientists to other countries.

• 1995, Iraq revealed its extensive bioweapons research and production capabilities during the Persian Gulf War.

• A Russian defector disclosed details of the former Soviet Union’s bioweapons program, including extensive production capabilities and genetic engineering of more virulent and resistant biological organisms.

• After its successful 1995 attack on Tokyo with sarin (chemical agent), an investigation into Japanese cult Aum Shinrikyo revealed that the terrorist group had attempted to obtain and deploy botulinum toxin and anthrax on several occasions.

Bioterrorism Today• Centers for Disease Control and Prevention (CDC) has identified 6 “Category A” biological agents that pose a threat to national security, considered high priority because of: • Ease of dissemination or transmissibility from person-to-

person; • High mortality rates;• Serious public health implications; • Ability to cause social disruption and public panic; and• Special preparedness requirements.

• 6 agents are smallpox, anthrax, plague, tularemia, botulism, and viral hemorrhagic fevers.

Bioterrorism Case Study: AnthraxOn October 16, 2001, a 47 year old US Postal Service employee

at the Brentwood processing facility in Washington DC developed fatigue, vomiting and diarrhea. He was initially diagnosed with the flu. Progressive symptoms prompted a second visit to the ER. By this time, concerns over an anthrax attack were well-publicized, and the physician recognized Joseph Curseen’s case as pulmonary anthrax. He was admitted to ICU, but on October 22, Mr. Curseen became 3rd person to die as a result of a biological attack on the US.

An extensive investigation revealed that B. anthracis spores had been delivered through the mail to several media outlets and Senator Daschle’s office.

Once it was over, 22 people had developed anthrax and 5 had died. To date, the perpetrator remains at large, although a suspect identified

Anthrax• Caused by the organism Bacillus anthracis• Transmitted as spores which can survive for long periods in the

environment• Can occur naturally in the US (very uncommon)• Clinical presentation: anthrax causes three different types of infection

• Cutaneous (skin form)—black lesion• Intestinal (abdominal form)• Inhalational (lung form)—presents with high fever, chest pain, cough and

severe shortness of breath; 89-96% fatal if untreated• Treatable with antibiotics• Not contagious (no person-to-person spread) • Public health strategies

• Identification of source of release and population exposed• Institution of treatment and prophylactic protocols• Information management• Coordination of the local, state and federal response

Smallpox• Caused by a virus• Naturally occurring smallpox eradicated in 1977 through a vigorous

worldwide vaccination campaign • Clinical presentation—approximately 12 days after exposure, patient

develops flu-like symptoms then the characteristic rash: similar to chickenpox, but all lesions are in the same stage of development and tend to be more prominent on the face and extremities

• Highly contagious • No proven treatment, just supportive therapy• Vaccination available for exposures• Key public health strategies

• Disease surveillance • Rapid laboratory confirmation• Isolation of contagious patients• Contact tracing• Institution of an aggressive vaccination program

Plague• Caused by Yersinia pestis bacteria• Naturally occurring outbreaks still occur worldwide• Clinical presentation--plague can take on many forms

• Most notorious form is bubonic plague which is transmitted by fleas and causes large, painful swollen lymph nodes (glands) termed “buboes”

• An aerosol attack would result in pneumonic (lung) plague, presenting as flu-like symptoms with watery then bloody sputum leading to severe respiratory distress, shock and death

• Treatable with antibiotics if detected early• Nearly 100% fatality rate when not treated • Public health strategies

• Syndromic surveillance• Identification of the source of the outbreak and exposed population• Contact tracing• Distribution of prophylactic antibiotics

Botulism• Caused by botulinum toxin, a nerve toxin produced by

bacteria Clostridium botulinum • Clinical presentation—following a terrorist attack with

aerosolized botulinum toxin, patients would present with paralysis in a descending fashion• Weakness of the eye muscles causes double vision• Weakness of the face and neck muscles causes difficulty speaking

and swallowing• Ultimately, weakness of the respiratory muscles leads to

respiratory arrest• Mental status is unaffected

Botulism• Botulism is not contagious• Recovery can take weeks to months• Key public health strategies

• Surveillance—botulism is a reportable disease• Development of surge capacity—ill patients require ventilators and

ICU care, both of which are limited in the US health system

Tularemia• Caused by the bacteria Francisella tularensis • If released into atmosphere, bacteria are highly virulent via

inhalational; • as few as 10-50 organisms could infect and individual

• Clinical presentation—can occur in various forms, affecting different parts of the body• Aerosol dissemination would result in non-specific flu-like symptoms

including fever, cough, chest pain and pneumonia, potentially severe• Not contagious• Treatable with antibiotics--fatality rate drops from 35% to 1-3%

with treatment• Public health measures

• Identification of the source of the outbreak to identify exposed population

• Prophylactic antibiotic distribution• Development of tularemia vaccine

Viral Hemorrhagic Fevers (VHF’s)• Comprised of 15 related viruses, 7 of which fall under CDC’s

category A status (e.g Ebola)• Each virus has specific s/s and predilection for certain organs,

but all result in uncontrollable bleeding• Sporadic outbreaks occur naturally• Clinical presentation—VHF should be suspected in any patient

presenting with severe flu-like illness, low blood pressure, bruising of the skin and bleeding from the eyes, nose, mouth, and/or intestines

• No curative treatment; requires aggressive ICU supportive care • Moderately to highly contagious• Public health measures

• Isolation and possibly quarantine• Contact tracing • Development of healthcare system surge capacity

Bioterrorism poses challenges for public health

• Attack is likely to be covert• Delay in onset of illness (incubation period)--makes

identification of the release site and other exposed individuals difficult

• Many biological agents cause non-specific, flu-like illnesses initially, which can delay diagnosis of the disease

• Most clinicians are unfamiliar with diseases related to biological terrorism due to the rarity of naturally occurring cases

• Very mobile society--contagious diseases have the potential to spread rapidly across borders

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Examples of public health strategies for combating bioterrorism• Epidemiologic investigation —the process of investigation that

determines the presence of an outbreak or biological attack, confirms the diagnosis, establishes the case definition, traces exposures and contacts, and characterized the outbreak or attack (where, when, etc.)

• Isolation —separation of patients with a communicable disease from non-infected individuals, preventing transmission of infection to others and allowing focused care

• Prophylaxis —medical intervention to prevent disease; antibiotics and antivirals are chemoprophylactics (medications), and vaccines are referred to as immunoprophylactics

• Quarantine —enforced isolation of the sick or exposed from healthy people to contain the spread of disease

• Surge capacity —ability to expand healthcare during periods of excessive and/or prolonged demand

Examples of public health strategies for combating bioterrorism (con’t)

• Syndromic use of certain symptom complexes and other health-related data to detect a potential outbreak or biological attack in its early phases so that public health measures may be rapidly mobilized to decrease morbidity and mortality; examples of surrogate data sources include school absenteeism, sale of over-the-counter medications, and ED presenting complaints

Conclusion• Biological weapons pose a significant threat to our nation. • Public health professionals play a vital role in preparing

for and responding to a biological attack. • Preparation for biological terrorism improves the public

health infrastructure for other current and emerging infectious diseases, such as pandemic influenza and Severe Acute Respiratory Syndrome (SARS).