Thursday, 28 March 2013

What is smallpox? - A brief overview

(http://science.nationalgeographic.com/science/health-and-human-body/human-diseases/smallpox-article/)

Smallpox is a contagious disease caused by the Variola virus. There are 2 type of Variola. Variola Major is the most severe and common form and has a fatality rate of around 30%. Variola Minor is a much less severe and less common presentation with a fatality rate of only about 1%.
Transmission
The disease was transmitted through prolonged and direct face to face contact however it can be spread by contact with infected bodily fluids and also by contact with contaminated objects such as bed linen and towels. According to BBC History (2011), blankets contaminated with smallpox were used as an early bio weapon by the British forces during the Pontiac rebellion of 1763. “Sir Jeffrey Amherst, the Commander-in-Chief of the British forces in North America, wrote to Colonel Henry Bouquet: 'Could it not be contrived to send smallpox among these disaffected tribes of Indians? We must use every stratagem in our power to reduce them.' The colonel replied: 'I will try to inoculate the [Native American tribe] with some blankets that may fall in their hands, and take care not to get the disease myself.' Smallpox decimated the Native Americans, who had never been exposed to the disease before and had no immunity.”
Symptoms
Someone suffering from smallpox is not contagious during the incubation period which can last 7 – 17 days but averages out at 13 – 14 days. They can go on to sometimes be contagious with onset of the initial or prodrome phase; this is when the 1st signs of the disease become evident. These symptoms include fever, head and body aches, malaise and occasionally vomiting. The person becomes most contagious with the onset of the rash. The rash first presents as small red spots on the tongue or mouth. As these spots develop into sores, they break open and deposit large amounts of the virus into the body via the mouth and throat. This is when the victim is at their most contagious. A rash now begins to develop on the skin, spreading from the face and usually cover the entire body within 24 hours. This rash becomes raised bumps which fill with a thick opaque fluid. These pustules scab over and, by the end of the second week of the rash forming, begin to fall off. The person remains contagious until the very last scab falls off.
Eradication
During the 20th Century smallpox killed more than 300 million people (Sebelius, 2011) making it one of the most feared diseases of its time. Between 1966 and 1980 the World Health Organization (WHO) embarked on a program to eradicate smallpox by a collaborative global vaccination programme. According to WHO (2013) “The last known natural case was in Somalia in 1977. Since then, the only known cases were caused by a laboratory accident in 1978 in Birmingham, England, which killed one person and caused a limited outbreak. Smallpox was officially declared eradicated in 1979.”
According to Sebelius (2011) “At that time, the WHO called on all nations to destroy their collections of smallpox virus or transfer them to the WHO-sanctioned collections at one of two labs in Russia or the United States”
Our assignment
It is these remaining stocks that our assignment concerns. We are asked to address the following question and complete a paper in support of our stance in relation to it.

One of the longest and most contentious international policy debates has swirled around the question of whether to destroy the last known stocks of the smallpox (Variola) virus, which are preserved at two World Health Organization (WHO)-authorized repositories in Russia and the United States. Although smallpox was eradicated from nature more than three decades ago, concerns surfaced in the early 1990’s that a few countries might have retained undeclared samples of the virus for biological warfare purposes.  Because a smallpox outbreak would be a global health emergency of major proportions, in 1999 the WHO approved a research program at the two authorized repositories to develop improved medical defences against the disease.

References
Centers for Disease Control and Prevention. (2007). Smallpox Disease Overview. Atlanta: Centers for Disease Control and Prevention [Online]. Available from: http://emergency.cdc.gov/agent/smallpox/overview/disease-facts.asp [27-03-2013]

Flight, C. (2011) Silent Weapon: Smallpox and Biological Warfare. London: BBC. [Online]. Available from: http://www.bbc.co.uk/history/worldwars/coldwar/pox_weapon_01.shtml [27-03-2013]

Sebelius, K. (2011) Why We Still Need Smallpox. [s.l.] The New York Times Company. [Online] Available from: http://www.nytimes.com/2011/04/26/opinion/26iht-edsebelius26.html?_r=0 [13-03-2013]

World Health Organization (2010) The Smallpox Eradication Programme - SEP (1966-1980). Geneva: WHO. [Online]. Available from: http://www.who.int/features/2010/smallpox/en/ [27-03-2013]

World Health Organization (2013) Smallpox. Geneva: WHO. [Online]. Available from: http://www.who.int/csr/disease/smallpox/en/ [27-03-2013]




Wednesday, 20 March 2013

Should The Smallpox Samples Be Saved - The Next Assignment

Our latest assignment focuses on the remaining samples of the smallpox virus.

In this assignment brief, we are asked to conduct research and produce a paper in support of whether we believe the smallpox samples should be retained or destroyed. We will then be presenting our findings and arguing our case in an open discussion.



http://textbookofbacteriology.net/themicrobialworld/Smallpox.html














Do you have an opinion on this topic? Please leave any comments below.

Wednesday, 6 March 2013

Syphilis

Obviously I am obsessed with 'crusty crotch' diseases. As part of our blogging assignment, we were supposed to add a fact sheet on a disease we have previously studied. Better late than never eh?

I have resisted the urge to post unsettling pictures of infected body parts!!
Infectious Disease Fact Sheet 
Name of DiseaseSyphilis
Name of causative agentTreponema Pallidum
Type of microbeBacterium
Gram-reactionNegative
Cell shape & arrangementSpiral shape
Epidemiology: 
Geographic PrevalenceWorld wide
ReservoirsHumans
Main transmission modeSexual/Blood contact with an infected person                                 Trans placenta in cases of congenital syphilis
Pathology: 
Major tissues/organs affectedDependent on the stage of the disease
Major signs/symptomsPrimary - Small painless spot on the area of infection      Secondary - rash on the palms of hands/soles of feet/back/genitals                                                                                                   Latent - No symptoms present                                                     Tertiary - Extensive damage to internal organs or soft tissue. Gummas (large ulcerated spots with are reluctant to heal)
SequalaeScaring to areas affected, death
LatencyDependent on the stage of the disease
Treatment: 
Main treatment methodsAntibiotics
Typical length of treatmentDependent on the stage of the disease.
Prophylactic measuresAbstain from sexual contact, monogamy, condoms (though not effective if the sore is not covered by the condom)