Bioterrorism and veterinary public healthPresentation Transcript
BIOTERRORISM AND VETERINARY PUBLIC HEALTH Dr. Shahnawaz ahmad I.V.R.I Div. Of Surgery
Definition of Bioterrorism Bioterrorism is the threat of use of biological agents by individuals or groups motivated by political, religious, ecological, social or for other ideological objectives to inculcate fear or cause illness or death in order to achieve their objectives (Carus 1998).
According to the United States Centers for Disease Control and Prevention (CDC) a bioterrorism attack is the deliberate release of viruses, bacteria or other germs (agents) or toxins used to cause illness or death in people, animals or plants .
BIOLOGIC WARFARE: HISTORY
14 TH century, Caffa: Attacking Tatar force catapulted cadavers of plague victims into city – outbreak of plague led to defeat
18 th century, Fort Pitt, North America: Blankets from smallpox hospital provided to Native Americans – resulted in epidemic of smallpox among tribes in Ohio River valley
Gen. Jeffrey Amherst, in a letter dated 16 Jully 1763, approved the plan to spread smallpox to Delaware Indians
1932-45, Manchuria: Japanese military physicians infected 10,000 prisoners with biological agents ( B. anthracis, N. meningitidis, Y. pestis, V. cholerae ) – 11 Chinese cities attacked via food/water contamination, spraying via aircraft
The Japanese army used Chinese prisoners to test bioweapons.
Reported cases of bioterrorism World war II – Polish resistance organizations used biological agents against German forces 1952 – Mau Mau, an independence movement in Kenya, used a plant toxin to poison livestock 1966 – Dr. M. Suzuki, a Japanese physician, infected health care providers and patients with S. typhi
1981 – Dark harvest groups got anthrax contaminated soil from Gruinard Island and damped it on Porton Down. 1984 – Rajaneesh in Portland, Oregon (USA) used S. thphimurium to contaminate restaurants salad bars 1995 – AUM Shinrikyo used sarin nerve gas in the Tokyo subway in Japan. 2001 - Anthrax contaminated mails sent to various people in USA
Casualties Incident Number of cases Number of deaths Polish resistance Not reported 200 Germans Mau Mau Not reported 33 head of cattle Dark Harvest None None Rajaneesh 751 (45 Hospitalized No deaths AUM Shrinkyo 5500 (641 seen at SJIH on day I & 349 following week 106 hospitalized at SLIH, 12 deaths ( 2 at SLIH) Dr. Suzuki 200 4 deaths Anthrax (USA) 22 4 deaths
Motive for Bioterrorism Incident Motive Polish resistance Resistance against foreign occupation Mau Mau Resistance against colonialism Dark Harvest Send a political message Rajneesh Win a local election by incapacitating the non-Rajneeshees voters AUM Shrinkyo Seize control of Japan through mass murder causing fear and apprehension Dr. Suzuki Revenge for unfair treatment he received at the medical training Anthrax (USA) Inculcate fear
BIOTERRORISM: WHY NOW?
Nuclear arms have great killing capacity but are hard to get.
chemical weapons are easy to get but lack such killing capacity
Biological agents have both qualities .
TRENDS FAVORING BIOLOGICAL WEAPONS
Biological weapons have an unmatched destructive potential
Technology for dispersing biologic agents is becoming more sophisticated.
The lag time between infection and appearance of symptoms generally is longer for biological agents than with chemical exposures.
Lethal biological agents can be produced easily and cheaply.
Biological agents are easier to produce clandestinely than are either chemical or nuclear weapons.
TRENDS FAVORING BIOLOGICAL WEAPONS
Global transportation links facilitate the potential for biological terrorist strikes to inflict mass casualties
Urbanization provides terrorists with a wide array of lucrative targets
The emergence of global, real-time media coverage increases the likelihood that a major biological incident will induce panic
CENTERS FOR DISEASE CONTROL BIOTERRORIST AGENTS: CATEGORY A
Easily disseminated or transmitted
High mortality, with potential for public
Require special action for public health preparedness .
THREAT TO ECONOMY The terrorists have an option to use exotic organisms to spread disease in animals and plants. Imagine somebody spread Foot and Mouth disease, Glanders, VEE, Rinderpest, Brucellosis, Swine fever, Fowl plague, Rabies and so on.
Similarly Rice blast, Stem Rust, Late blight of potato, Black Rust and Maize Rust and so on would destroy all the crops and shatter the economy of the country.
Eg:- Irish Potato Famine in 1940 due to Potato Blast
Half a million people died of starvation and half a million people migrated. It took one century for the country’s economy to recover.
BIOLOGICAL WARFARE: IMPACT [ release of 50 kg agent by aircraft along a 2 km line upwind of a population center of 500,000 – Christopher et al., JAMA 278;1997:412
Agent Downwind No. dead No.
reach, km incapacitated
Rift Valley fever 1 400 35,000
Tick-borne encephalitis 1 9,500 35,000
Typhus 5 19,000 85,000
Brucellosis 10 500 125,000
Q fever >20 150 125,000
Tularemia >20 30,000 125,000
Anthrax >20 95,000 125,000
Biological Delivery Methods
Food / Water
Air handling systems
CHARACTERISTICS OF BIOWARFARE
Potential for massive numbers of casualties
Ability to produce lengthy illnesses requiring prolonged and intensive care
Ability of certain agents to spread via contagion
Paucity of adequate detection systems
Presence of an incubation period, enabling victims to disperse widely
Ability to produce non-specific symptoms, complicating diagnosis
Ability to mimic endemic infectious diseases, further complicating diagnosis
Agents acquired from contaminated clothes
Variola major (smallpox)
Bacillus anthracis (anthrax)
Coxiella burnetii (Q fever)
Yersinia pestis (plague)
Remove clothing, have patient shower
Place contaminated clothes in impervious bag, wear PPE
Decontaminate environmental surfaces with EPA approved
germicidal agent or 0.5% bleach (1:10 dilution)
Bioterrorism agents: Laboratory risk Agent BSL Laboratory Risk B. anthracis 2 low Y. pestis 2 medium F. tularensis 2/3 high Brucella spp . 2/3 high Botulinum toxin 2 medium Smallpox 4 high Viral Hemorrhagic fever 4 high
ANTHRAX IN THE US, 2001
Locations: FL, NY, DC, NJ, CT, VA
Mechanism: Via the mail (4 letters positive)
Infections: 22 cases
Cutaneous anthrax: 11 (fatality rate = 0)
Inhalation anthrax: 11 (fatality rate = 45%)
60 day course recommended: ~5,000
UNEXPECTED FEATURES OF ATTACK
Targets (news media)
Vehicle (US mail)
Source of strain (US, probably weaponized)
Translocation of spore through envelope
Airborne acquisition in mail facilities
Wide spread contamination in mail facilities
Transmission via mail-to-mail contamination
No person or group has claimed responsibility
Agent: Bacillus anthracis , a Gram-positive,
spore forming non-motile bacillus
(straightforward lab identification)
Reservoir : Herbivores (cattle, goats,
capable of surviving in the environment for
Contact, ingestion, or inhalation of infective spores
Sources of infection: Contaminated hides, wool, hair, bone, meat, or other animal products
SVERDLOVSK ANTHRAX OUTBREAK
Site: Sverdlovsk, USSR
Cause: Accidental release from military microbiologic facility – Military report noted: “Filter clogged so I’ve removed it. Replacement necessary”
Impact: 68 human deaths, 79 human cases, multiple animal deaths (sheep, cows )
INHALATION ANTHRAX, US Prominent superior mediastinum, ?small left pleural effusion B. ANTHRACIS : PERIPHERAL BLOOD SMEAR
Cutaneous Anthrax, US 7 mo male infant hospitalized with 2 day history of swelling left arm and weeping lesion at left elbow. Patient had been at his mother’s office at a TV network. Biopsies yielded B. anthracis.
Public Health and Clinical
Due to infection with the bacterium
– Primary septicemia/
– Primary pneumonic
PERIPHERAL BLOOD SMEAR
Public Health Features
Most cases in U.S. occur in southwest
Pneumonic plague can be transmitted person to person via respiratory droplets
PLAGUE: CLINICAL FEATURES
Incubation period: 1-4 days (pneumonia), 1-7 days (bubonic or septicaemic)
Onset and severity dependent on amount of toxin absorbed
Incubation variable 2 hrs to 8 days after ingestion
Ptosis, diplopia, blurred vision, loss of head control
Deep tendon reflexes diminish
Death results from airway obstruction;
Respiratory and diaphragmatic muscle paralysis
Index of suspicion for botulism; clusters of cases
Supportive care and administration of passive equine antitoxin
Botulinum Toxin as a Bioweapon
Aum Shinrikyo 1990, 1993, 1995: attempted aerosol dispersion in Japan
Japan WW II (Unit 731): fed cultures to prisoners in China
US bioweapons program
Soviet Union program: gene splicing
Iraq 19,000 liters weaponized
? Iran, North Korea, Syria
Viral Hemorrhagic Fevers
Argentine hemorrhagic fever
Bolivian hemorrhagic fever
Marburg Ebola hemorrhagic fevers
Ebola and Marburg – Etiologic agents
Flioviridae family viruses
Among the most virulent viruses (25-90% case fatality depending on strain)
Humans are incidental hosts Marburg
Clinical features - VHF
Severe multisystem syndrome
Overall vascular system damage
Body’s ability to regulate itself is impaired
Often accompanied by hemorrhagic (in itself not usually life threatening)
Ebola & Marburg Viruses - clinical course
Sudden onset of flu-like illness
May progress to nausea, vomiting, diarrhea, abdominal pain, photophobia, maculopapular rash, DIC, internal and external hemorrhage, multiorgan failure with jaundice and renal insufficiency
Atlanta, Georgia: Electron Micrograph: Ebola virus causing African Hemorrhagic Fever. (Courtesy of the National Archives, 82-424)
Marburg & Ebola – Occurrence
Naturally occurring sporadic outbreaks in Africa
Cases have occurred in West as a result of exposure to animal reservoirs
Russian biowarfare program
Iraq is believe to have tried
Ebola and Marburg - transmission
Direct contact with infected tissue and body fluids or contaminated objects
Probably aerosol inhalation
Borio, et al JAMA consensus statement 2002 Maculopapular Rash in Marburg Disease Ocular Manifestations in Bolivian Hemorrhagic Fever
Psychological and Social Factors during bioterrorism
Magical thinking about microbes
Fear of invisible agents Fear of contagion
Anger at Terrorist/Government
11. Loss of faith in social institutions
12. Attribution of arousal symptoms to infection
MANAGEMENT OF PEOPLE WITH PSYCHOLOGICAL PROBLEMS
care of health workers
Critical incidence stress management (CISM) for rescue workers
Prevention of public fleeing
Confidence building by the medical workers
Dealing with emotional and psychological problems while dealing with the dead.
Care of emergency workers, medical and paramedical workers
Critical incidence of stress debriefing(CSID)
8.Prevention of group panic 9. Avoidance of emotion based responses (Knee jerk quarantine) 10. Effective risk communication 11. Control of symptoms secondary to hyper arousal 12. Reassurance 13. Management of anger fear (Diazepam and other anxiolytic drugs) 14. Provision of respite as required 15. Social support of the community
Role of Clinicians
Be prepared to diagnose and treat BT diseases
Keep alert to unusual disease patterns
Use reportable disease system to alert public health officials of a potential problem
Get involved in disaster planning process
Clusters of patients with the same disease or syndrome
there is more cases than would be expected
cases are geographically or temporally clustered
the illness is unexplained
there are multiple atypical presentations of the disease
the mortality or morbidity is higher than expected
Even a single case may be a signal
Caused by an uncommon agent
Unusual for region, age group or season
Fulminant disease in otherwise healthy patient
Similar genetic type of agent from distinct sources
Unusual, atypical, genetically engineered, or antiquated strain
Atypical aerosol, food, or water transmission
Concurrent animal disease
DETECTION OF OUTBREAKS
Triage, psychological aspects, lab support, public information
Post-exposure prophylaxis, treatment of infected persons
DETECTION OF OUTBREAKS
A rapidly increasing disease incidence
An unusual increase in the number of people seeking care, esp. with
fever, respiratory, or gastrointestinal symptoms
An endemic disease rapidly emerging at an uncharacteristic time or in
an usual pattern
Lower attack rate among persons who had been indoors
Clusters of patients arriving from a single local
Large numbers of rapidly fatal cases
Any patient presenting with a disease that is relatively uncommon and
has bioterrorism potential
DETECTION AND IDENTIFICATION OF BIOWEAPON AGENT
The conventional microbiological methods viz., culture, immunodetection, serology, molecular identification take long time (hours to days)
Several biodetectors (bioluminometer) based on the principles of bioluminescence and biofluorescence are being developed _ Fire fly luciferage gene .
There are various types of biosensors such as immunosensors, nucleic acid sensors, tissue based sensors and laser sensors
EMERGING INFECTIONS AND BIOTERRORISM
New diseases have also appeared within the developed nations including United States. Some of these include:
New variant of Creutzfeldt -Jakob disease
West-Nile virus disease
Hantavirus pulmonary syndrome (HPS)
Multi-drug resistant TB,
Antibiotic resistant staphylococcal, enterococcal and pneumococcal infections
Diarrhoeal diseases caused by the parasite Cryptosporidium parvum and then certain strains of Escherichia coli bacteria.
Factors contribute to the emergence and re-emergence of infectious diseases 1. Unprecedented worldwide population growth draining the natu ral resources 2. Overcrowding in cities with poor sanitation 3. Rapid and increased international travel 4. Increased international trade in animals and food products 5. Mass distribution of food and unhygienic food preparation practices 6. Increased exposure of humans to disease vectors and reservoirs in nature 7. Man-made changes to the environment and climatic changes which have a direct impact on the population of insect vectors and animal reservoirs. 7. Misuse of antibiotics leading to the evolution of resistant microbes.
Impact of biological agents on national economies
Highly pathogenic avian influenza, Hong Kong
The outbreak of highly pathogenic avian influenza (HPAI) type A (H5N1) in live market chickens in Hong Kong resulted in 6 million deaths and killing of 1.4 million birds.
Nipah virus, Malaysia
Nipah virus, a previously un known virus was identified in 1998, primarily in pigs and in humans in Malaysia.
The virus caused over 250 human cases resulting in 100 deaths. Approximately 1 million pigs were killed. Other countries in the region banned he importation of pork products.
Malaysia authorities blamed the disease on a deliberate attack by rival Asian countries trying to slowdown Malaysia’s recovery from the Asian Economic Crisis of the 1997.
Foot and Mouth disease, Taiwan
The 1997 Foot and mouth disease outbreak in Taiwan had a devasting effect on export oriented pork industry.
The virus is believed to have been brought into Taiwan through smuggled animals, meat products or illegal immigrants from mainland China.
The epizootic resulted in the depopulation of 3.8 million pigs.
At one point the outbreak it was blamed as deliberate introduction of FMD into Taiwan by mainland China. The economic impact on Taiwan has been estimated in the billions of dollars.
Less developed nations can produce biological weapons that are as lethal as nuclear weapons include: Iran, Iraq, Israel, North Korea, China, Libya, Syria and Taiwan.
Recent terrorist activities in India underscores it’s vulnerability to bioterrorism and the need for a comprehensive plan to defend against an attack.
Currently, it does not have the infrastructure to quickly detect and identify many pests and pathogens nor is the country able to respond to even small-scale attack.