Summary about Disease
Variola, commonly known as smallpox, is a contagious disease caused by the variola virus. It's characterized by a distinctive skin rash with fluid-filled blisters (pustules) all over the body. Smallpox was eradicated globally in 1980, thanks to a successful vaccination campaign. However, samples of the virus are still maintained in secure laboratories for research purposes. The disease was historically devastating, with a high mortality rate and significant scarring in survivors.
Symptoms
Initial symptoms typically include: Fever, Malaise (general feeling of discomfort, illness, or unease), Headache, Severe fatigue, Back pain, Abdominal pain, Vomiting. A characteristic rash then develops, starting as small red spots, progressing to papules (raised bumps), vesicles (small blisters filled with clear fluid), and finally pustules (blisters filled with pus). The pustules scab over, and the scabs eventually fall off, leaving scars.
Causes
Smallpox is caused by the variola virus, a member of the orthopoxvirus family. The virus is spread through direct contact with infected individuals, contaminated objects (such as bedding or clothing), or through airborne droplets released when an infected person coughs or sneezes.
Medicine Used
There is no specific cure for smallpox. Treatment focused on supportive care to alleviate symptoms and prevent secondary bacterial infections. Vaccination with the vaccinia virus (not variola) provided protection against smallpox. The antiviral drug tecovirimat (TPOXX) is approved for the treatment of smallpox in the event of a re-emergence. Other antivirals like brincidofovir and cidofovir may also have some efficacy.
Is Communicable
Yes, smallpox is highly communicable. It is spread through direct and prolonged face-to-face contact with an infected person, contact with contaminated objects, and potentially through airborne droplets. Transmission is most likely during the first week of the rash, when the concentration of the virus is highest.
Precautions
The primary precaution against smallpox is vaccination. Routine smallpox vaccination is no longer practiced for the general public due to the eradication of the disease. However, the vaccine is available for laboratory workers who handle the virus and for military or healthcare personnel who might be at risk in the event of a bioterrorism attack. Other precautions include: Isolation of infected individuals, Proper disposal of contaminated materials, Use of personal protective equipment (PPE) by healthcare workers.
How long does an outbreak last?
Historically, smallpox outbreaks could last for several months, or even years in some areas, depending on the effectiveness of control measures. With effective vaccination and isolation, outbreaks can be contained much faster.
How is it diagnosed?
Diagnosis of smallpox is typically based on clinical presentation (the characteristic rash) and laboratory testing. Laboratory tests include: PCR (polymerase chain reaction) to detect the variola virus DNA, Virus isolation and culture, Electron microscopy to visualize the virus particles. It is crucial to differentiate smallpox from other diseases with similar rashes, such as chickenpox.
Timeline of Symptoms
Incubation Period (7-19 days, average 12-14 days): No symptoms.
Initial Symptoms (2-4 days): Fever, malaise, headache, severe fatigue, back pain, abdominal pain, vomiting.
Early Rash (approx. 4 days): Small red spots appear on the tongue and in the mouth. These sores break open and spread large amounts of the virus into the mouth and throat. The rash starts on the face and spreads to the arms, legs, hands, and feet. Within a day or two, the rash turns into small, raised bumps.
Papular Stage (approx. 1-2 days): The bumps become raised.
Vesicular Stage (approx. 2 days): The bumps fill with a clear fluid.
Pustular Stage (approx. 5-7 days): The fluid in the bumps turns into a thick, opaque liquid (pus).
Scab Stage (approx. 2 weeks): The pustules begin to scab over. Scabs eventually fall off, leaving pitted scars. The person is contagious until all scabs have fallen off.
Important Considerations
Although eradicated, smallpox remains a potential threat due to the existence of virus stocks in secure laboratories and the possibility of bioterrorism. Maintaining vigilance and preparedness is crucial. Rapid detection, isolation, and vaccination are essential for controlling any potential outbreak. Differential diagnosis from other rash illnesses is also critical.