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Ayesha Roofi. FA08-BBS-016. TOPIC. SMALL POX. CONTENTS. INTRODUCTION HISTORY Types LIFE CYCLE TRANSMISSION PREVENTION TREATMENT DIAGNOSIS Vaccination THREATS. INTRODUCTION. Serious illness Small pox from Latin “ variola ” which means “spotted” Acute Infectious Contagious.
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Ayesha Roofi FA08-BBS-016
TOPIC SMALL POX
CONTENTS • INTRODUCTION • HISTORY • Types • LIFE CYCLE • TRANSMISSION • PREVENTION • TREATMENT • DIAGNOSIS • Vaccination • THREATS
INTRODUCTION • Serious illness • Small pox from Latin “variola” which means “spotted” • Acute • Infectious • Contagious
History • Originated thousand years ego. • First originated in Africa then India and china. • The first recorded smallpox epidemic was in 1350 BC during the Egyptian-Hittite war • Smallpox reached Europe between the 5th and 7th centuries and was present in major European cities by the 18th century. • Epidemics occurred in the North American colonies in the 17th and 18th centuries • At one time smallpox was a common disease in every country throughout the world except Australia and a few isolated islands. • Millions of people died in Europe and Mexico as a result of widespread smallpox epidemics.
Fall of small pox • Variolation • 1700 it was become common in India and china • It was criticized in 1700s. • Edward Jenner contribution in eradication of small pox • 1796 he took fluid from cow pox pustules and inject
The last outbreak of smallpox in the United States occurred in Texas in 1949 with 8 cases and 1 death. Even though most of North America, Western Europe, Australia, and New Zealand were free of smallpox by this time, other countries such as Africa and India continued to suffer from epidemics.
In 1967 the World Health Organization (WHO) started a worldwide campaign to eradicate smallpox. This goal was accomplished in 10 years due in a large part to massive vaccination efforts. The last endemic case of smallpox occurred in Somalia in 1977. On May 8, 1980, the World Health Assembly declared the world free of smallpox.
Types • Variola Minor • Milder symptoms • Less common • Variola Major • Most common and severe with high fever • This is further broken into 4 types • Distinguish on the basis of PCR testing.
Variola major More severe, with high fever and symptoms Most common
Variola major • Variola major is further broken into four types. • Ordinary variola • Hemorrhagic variola • Modified variola • Flat variola
Ordinary (the most common, consisting of 90% of the cases. pustules could form intermittently over the body, or even be so numerous that not one clean patch of skin would be left
Hemorrhagic virus (Very rare and very severe. The virus causes blood vessels to seep from all parts of the body, even within the eyes. Unable to move or speak, patients with hemorrhagic pox often are aware of what is happening to them almost to the point of death. ),
Modified virus modified (develops in those that have been previously vaccinated – usually mild),
Flat and flat (the pustules never raise up, but are discolorations in the skin that cause it to slough off).
Structure • Most complex structure among animal viruses • DNA is embedded in core (red) • They have lateral bodies in depression (purple) • They viral contains several host membranes (green ,blue)
CLASSIFICATION OF THE SMALLPOX VIRUS • GENOME: Linear Double Stranded DNA • Family: Poxviridae • Subfamily: Chordopoxvirinae • Genus: Orthopoxvirus • Species: Variola
Sign and symptoms • Symptoms start to appear within 12-14 days • It includes • High fever • Headache • Backache • First a small rash appear in mouth and hand then it starts spreading on trunk region
Transmission • Direct contact with body fluids • Face to face contacts • Contaminated clothes, bedding • Coughing, sneezing,talking.
Preventions • The patient suspected to have small pox should be isolated • People and house holds who contact face to face with patient should be vaccinated and placed under surveillance. • Those who develop small pox by contact should be isolated. • For the patients in the hospital airborne precautions should be followed. • Gloves,masks,gowns should be worn before treating these patients.
Treatment • DIAGNOSIS • Diagnosis of smallpox is based on clinical presentation of symptoms in the patient and is confirmed by laboratory testing • The patient of this disease are easily recognizeable because of having special kind of rash on patiets skin. • These rashes come up as a blisters on a skin and fiiled with a fluid forming a crust. • This might sound like a chicken pox but blisters looks different then a chicken pox blister. • Other symptoms may include headache,fever,bachache,illnessnd feeling tired.
VACCINE • A vaccine , a type of shot, can prevent infection with the virus that causes smallpox. Several Years ago, people were vaccinated against smallpox. • Today, smallpox vaccines aren't given because nobody has had the disease for many years. Even though if a person get a smallpox vaccine right now, there is a supply of the vaccine in case there's an outbreak of the disease. • Scientists also are working to make more vaccine to have on hand for the future. • vaccination within 1 to 3 days after exposure to smallpox can prevent infection with smallpox
Is there any medicines for small pox? • There are no pills that can treat smallpox, but scientists are doing research to try to develop medicine for the disease. • If someone does become infected with the smallpox virus, getting the vaccine within a few days of becoming infected can lessen the disease's symptoms.
Viral replication • Attachment • Penetration • Release of genome • Replication of genome (DNA) • Assembly of newly formed DNA • Enveloping • Releasing
Entry of viral particles vary • The mode of entry into cells varies depending on the virus form • Endocytosed in the form of bubbles (EEV) • Entry by fusion with plasma membrane (IMV)
Life cycle • Incubation period • Initial symptoms • Early rash • Pustular rash • Pustules and scabs • Resolving scabs • Scabs resolved
Incubation period • Duration is 7-17 days but average duration is 12-14 days. • Not contagiousPeople do not have any symptoms and may feel fine.
The rash appears 2 to 4 days after the patient first becomes ill with fever. On the first day of rash a few raised spots called papules appear. They are usually seen first on the face, and subsequently on the body and extremities. On the right side of this picture, a few small papules may be seen. Unless it is known that the patient has been exposed to the virus or in contact with a smallpox case two weeks before, one may not suspect the diagnosis at this ti
Initial symptoms • (Duration: 2 to 4 days)-Sometimes contagious*-The first symptoms of smallpox include fever (101-104 degrees Fahrenheit), malaise, head and body aches, and sometimes vomiting. - People are usually too sick to carry on everyday activities.
On the second day of rash, more papules appear. Although they differ somewhat in size, note that they all have a very similar appearance.
Early rash • Early Rash(Duration: about 4 days)-Most contagious
By day 3, the rash has become more distinct and raised above the skin surface. Fluid is accumulating in the papules to form vesicles.
Rash Distribution • -A rash emerges first as small red spots on the tongue and in the mouth.- These spots develop into sores that break open and spread large amounts of the virus into the mouth and throat. At this time, the person becomes most contagious.-The skin rash appears as the sores in the mouth break down, usually spreading to all parts of the body within 24 hours. -As the rash develops the fever drops and people start to feel better.-By the third day of the rash, the rash becomes raised bumps.-By the fourth day, the bumps fill with a thick, opaque fluid and often have a depression in the center that looks like a bellybutton. (This is a major distinguishing characteristic of smallpox.)-The fever returns with the onset of the raised bumps, and remains until scabs form over the bumps.
By day 4, the vesicles are more distinct. Although they contain fluid, they feel very firm to the touch. When broken, they do not collapse because the fluid is contained in many small compartments.
By day 5, the fluid in the vesicles has become cloudy and looks like pus. At this stage, the pocks are called pustules. At this time, the fever usually rises and the patient feels more ill than before
Pustular rash • (Duration: about 5 days)-Contagious-The bumps become pustules—sharply raised, usually round and firm to the touch as if there is a small round object under the skin. People often say the bumps feel like BB pellets embedded in the skin.
Pustules and scabs • (Duration: about 5 days)-Contagious-The pustules begin to form a crusty scab.-Most of the sores usually have scabbed over after the second week.
On day 7, the rash is definitely pustular. Note that the pocks, although varying somewhat in size, all resemble each other in appearance. The rash is now so characteristic that there should be no mistake in diagnosis.
During days 8 and 9, the pustules increase somewhat in size. They are firm to the touch and deeply embedded in the skin.
Gradually the pustules dry up and dark scabs form. The scabs begin to appear between 10 and 14 days after the rash first develops. The scabs contain live smallpox virus. Until all scabs have fallen off, the patient may infect others.
Resolving scabs • (Duration: about 6 days)-Contagious -As the scabs begin to fall off, they are replaced by pitted scars. .-The person remains contagious until all of the scabs have fallen off. This takes about three weeks after the rash appears.
By day 20, the scabs have come off and light-coloured or depigmented areas are observed. Over a period of many weeks the skin gradually returns to its normal appearance. However, scars which last for life may remain on the face. Such scars are an indication of previous infection with smallpox
Scabs resolved • -Not contagious-Scabs have fallen off. • Person is no longer contagious. * Smallpox may be contagious during the prodrome phase, but is most infectious during the first 7 to 10 days following rash onset.
Complete infectious cycle In this slide, the development of the rash is followed through consecutive stages. The numbers indicate the days after onset of rash on which the pictures were taken. Papules are seen on days 3 and 4; vesicles on day 5; pustules on days 7 and 9; and, finally, scabs on day 13.
This diagram shows the density of bristles is more on face as compared to trunk
