Adeno & Pox 07s

ADENO & POX VIRUS

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Adeno virus DNA, non enveloped

Host specific virus

Appearance of space vehicle

> 40 types

Infection of RT, Eye, bladder, intestine & heart

Respiratory Acute febrile pharyngitis

Pharyngo - conjunctival fever Swimming pool conjunctivitis

Infants & young children

School age children

Acute respiratory disease

New military recruits

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Ocular

Infantile Gastoenteritis 1-15% of all viral diarrheal disease in children

Follicular conjunctivitis Self limiting

(Serotypes 40 - 41) Hemorrhagic cystitis

Epidemic Kerato conjunctivitis

Occurs primarily in boysself limited

Shared towels, ophthalmic soln. unsterile instruments Leads to corneal opacity (ship yard eye) 11/26/08

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(Serotypes 11 - 21) Left ventricular dysfunction Both children & adults

Lab diagnosis Specimens

Swabs from throat, eye, urine or feces

Culture

Human embryonic kidney, HeLa, HEP-2

Identification

CPE- Grape like clusters

Serology

Rise in titre of Abs in paired sera - ELISA

Treatment

No drugs

Prevention

Live attenuated vaccine – only military population

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Molluscum Contagiosum DNA virus belong to pox viruses Causes pink or pearly white umbilicated wart like lesions on skin Children & young adults Spreads by direct contact (STD)

Eosinophilic intra cytoplasmic inclusions

Can not be cultured Diagnosis by clinical picture & HPE HPE: Molluscum bodies Disappears within 1yr To avoid spread - Surgical removal / Cryotherapy/ Laser 11/26/08

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Avoid touching, rubbing, scratching, shaving over the area

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Abandoned small pox hospital 11/26/08

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In the early eighteenth century, especially in Britain, there was renewed interest in oriental medical practice, and in particular the use of inoculation against smallpox (variolation). This arose in part from the fact that, in 1718, while resident at the Embassy in Istanbul, Lady Mary Wortley Montagu was so determined to prevent the ravages of smallpox and so impressed by the Turkish method that she ordered the Embassy surgeon at Istanbul, Charles Maitland, to inoculate her 5-year-old son in March 1718. She herself had suffered from a bout of smallpox in 1715 that disfigured her beautiful face, and her 20year-old brother had died of the illness 18 months earlier.

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Small pox - Variola Virus 2 clinical varities Highly fatal seen in Asia - Variola major (classical small pox) Non - fatal seen in Latin America -Variola minor (Alastrim) Vaccinia virus

Artificial virus

Employed as a vector for developing recombinant vaccine Brick shape, can be seen under microscope – 300 nm By inhalation- reach reticulo endothelial cells – viremia – seeding of mucosa & skin 11/26/08

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Pocks of small pox virus on CAM of developing chick embryo

Pocks of variola are small, shiny, white, non necrotic & non hemorrhagic

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Pocks of vaccinia are large, irregular, greyish, necrotic & hemorrhagic

Features

Small pox

Chicken pox

Distribution of Rash

Centrifugal

Centripetal

Palms & soles involved

Seldom affected

Axilla free

Axilla affected

Deep seated

Superficial

Vesicles multilocular & umbilicated

Unilocular & dew drop appearance

Only one stage of rash at one time

Pleomorphic: rash in successive crops

No area of inflammation around vesicles

Area of inflammation around vesicles

Slow – macule, papule, vesicle, pustule

Rapid

Scabs form after 10-14 days

After 4 - 7 days

Characteristics of Rash

Evolution of Rash 11/26/08

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Successful eradication No known animal reservoir No long term carriers Life long immunity after recovery Case detection was simple with characteristic rashes Subclinical infections did not transmit disease

Highly effective vaccine - heat stable & long term protection

International cooperation 11/26/08

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Unanswered Questions Are there hitherto unknown animal reservoirs of small pox virus?

Can another orthopox virus be transferred to small pox virus?

Are we absolutely certain that laboratory infection such as that which occurred in Birmingham, England will not occur?

Will animal pox (Monkey) eventually replace the eradicated small pox virus as a wide spread pathogen?

Lastly could biological warfare with small pox virus be waged in future? 11/26/08

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Global Health Histories July 2006

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1980 “The

end of smallpox – but for WHO it is only the end of the beginning…victory over smallpox has implications that go far beyond the individuals directly concerned…It reasserts our ability to change the world around us for the better.“

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Hal fdan Mahl er , Director- General , W HO 1973- 1988.

1988 “For centuries, variola virus stalked the world with impunity, causing unmeasured suffering, death and blindness. Today it is confined to glass vials kept under high security in six laboratories…smallpox is a disease which can be confined to history – the first disease ever eradicated by man.”

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Donald Ainslie Henderson, Chief, Smallpox Eradication, WHO 1966-1977.

April 1999 "While we fervently hope smallpox would never be used as a weapon, we have a responsibility to develop the drug and vaccine tools to deal with any future contingency – a research and development process that would necessarily require smallpox virus.” US President Bill Clinton 11/26/08

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May 1999 During the World Health Assembly, the USA successfully argues against calls for the destruction of smallpox stocks held in the USA and Russia, recommending instead that stocks should be kept for therapeutic research purposes

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June 9, 1999 "If used as a biological weapon, smallpox represents a serious threat to civilian populations because of its case-fatality rate of 30% or more... Although smallpox has long been feared as the most devastating of all infectious diseases its potential for devastation today is far greater than at any previous time.“ Henderson et al. JAMA 1999;281:2127-2137 11/26/08

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After September 11, 2001 2002: US government orders 200 million doses of smallpox vaccine, costing $428 million. The UK government orders 20 million doses, costing £32 Million 2003: UK government sets up Health Protection Agency to help prevent terrorist attacks and limit their impact 2003: WHO, US, UK, European Commission and 6 other countries stage "Global Mercury “ smallpox alert exercise 11/26/08

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September 2003: Global Mercury 

In this scenario, two travelers collapse at Vancouver airport with a suspicious rash. They confess they are members of a terrorist group who have infected themselves with smallpox and dispersed to 14 countries just as their infectivity is peaking.



Quarantine officers issue an international alert. Frantic communications ensue among the affected countries. Problems include cross-border coordination, language difficulties and equipment failures.



Afterwards, the exercise was described as a well coordinated, realistic and valuable test of international communications. "Participants believe that similar exercises should be scheduled regularly, possibly annually."

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Exercise Global Mercury

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2005 "We are not saying there might not be fatalities, but we could prevent any widespread disaster.”

Gordon MacDonald, Head of Emergency Strategic Planning, UK Health Protection Agency The Times August 24, 2005

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2005 "We shouldn’t be complacent but it is important for the public to realise that while there would be deaths, as there would be in a conventional attack using explosives, there wouldn't be the kind of widespread catastrophe they might imagine.” Dr Nigel Lightfoot, Director of Emergency Response Capability, UK Health Protection Agency . 11/26/08

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2006: WHO Global Outbreak Network

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Conclusions The risk of a terrorist smallpox attack is currently low but is being taken very seriously  Many countries are staging prevention and control exercises  Multimillion doses of vaccine are being held in readiness  WHO is urging countries to develop and strengthen preparedness plans 

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