Smallpox back? Learn how to protect yourself.
03/06/2022 | Catarina Vilela - Mipmed
The emergence of several outbreaks of monkeypox in several countries outside Africa, where the disease is endemic, has resurrected in our memories the terrible disease human smallpox, which for centuries claimed lives! Europe has the highest number of monkeypox cases ever, and the World Health Organization (WHO) believes this number will grow. This situation could have an impact on the economy, public health and even ecology, as this virus can infect mammals!!
Smallpox is a rare disease of the human smallpox family - it is an orthopoxvirus. However, monkeypox is milder and milder. The cause for alarm at the moment regarding its transmission is that it is presenting interhuman cases.
How did monkeypox infect humans?
The virus that causes monkeypox has been known for over 60 years. It was first detected in 1958 in Congo when two laboratory monkeys contracted a disease similar to human smallpox. For this reason, the disease has this name.
The first case was detected in a human, a 9-month-old baby, in the 1970s, in Congo. According to the baby's father, the family used to eat monkey meat, and in this way, the virus may have been transmitted by eating the animal's meat.
What is the transmission of smallpox from monkeys?
Monkeypox is not a very contagious disease, as it is spread by very close contact with an infected person. The virus enters the human body through lesions on the skin, through the respiratory system or through the eyes, nose and mouth.
- Touch clothes, sheets, and towels used by someone with skin lesions caused by the disease.
- Touch blisters or crusts on the skin of people with a rash.
- People with monkeypox cough or sneeze.
- Person-to-person transmission can occur through close contact, through droplet particles and respiratory secretions (distance less than 1 meter), in addition to lesions on the skin of an infected person or recently contaminated objects.
- Through the placenta from mother to fetus or during close contact during and after birth.
- So far, the virus has not been described as a sexually transmitted disease, but it can be passed on during sexual intercourse, due to the proximity between the people involved. Authorities point out that anyone, regardless of their sexual orientation, can be contaminated.
- Zoonotic transmission from animal to human: direct contact with blood, body fluids, skin lesions from infected animals, mucous membranes, bites, and scratches caused by monkeys, rats, and squirrels.
- Eating raw or undercooked meat from infected animals is a risk factor.
Knowing the transmission routes makes it possible to establish effective prevention measures.
So what to do to prevent contamination?
The use of masks, distancing (more than one meter away), washing and sanitizing hands regularly, cleaning surfaces with any detergent (it is not necessary to contain alcohol), safe sex, are ways to avoid contagion, by monkey pox.
What are the differences and similarities between human smallpox and monkeypox?
The difference is related to the degree of lethality and the similarity with the way the disease manifests itself.
The mortality of human smallpox is higher (up to 30%) than monkeypox (which is self-limiting and has a lethality of 3 to 6%).
Monkeypox is a milder disease than human smallpox. It does not usually present major complications, registering a few serious cases that resulted in death.
Both have common signs and symptoms. They present a picture of normal flu, which progresses to chills, body pain, weakness, exhaustion, and increased size of the nodes. This last feature is not very common in smallpox. The first symptoms appear between 5 and 21 days after contact with an infected person. Symptoms tend to pass naturally.
Five to ten days after infection, lesions appear initially on the head and throat, then on the hands and feet. These rashes increase in size, developing a pustule, with pus inside.
Smallpox has a greater potential for transmission via the respiratory route. Monkeypox, on the other hand, requires closer contact, although the respiratory route can also transmit it, it does not spread so easily through the air.
The transmission of monkeypox occurs mainly through bodily fluids (blood droplets, saliva, semen).
Belgium has established that all those infected with monkeypox must remain in quarantine. It was the first country to enact measures in this regard. They require 21 days of isolation, why? Is it an efficient way of acting right now, which can be adopted by other countries that are reporting cases?
Yup. The incubation period ranges from 7 to 14 days. A person can transmit it before showing symptoms. When symptoms start, they last for 3 to 4 weeks. The ideal is to isolate infected people until the bodily injuries heal. These are health measures necessary to contain a disease ( block local interpersonal transmission ) that does not yet have a specific treatment.
Can a new pandemic start?
Although the cases are considered unusual, health officials believe that monkeypox poses no major risks and that the disease will not cause a new pandemic. Simple actions such as good hygiene and safe sexual contact reduce the risk of infection. It is a known virus that can be controlled with known measures - case investigation, contact tracing, and isolation at home in case of infection.
What is inter-human transmission?
It is a human-to-human transmission by close contact. And this is a difference in relation to the form of contagion of smallpox or Covid. Monkey smallpox is less contagious, as it has to have more intimate contact, less than a meter away, from the infected person.
How is the treatment? Are there any medications already?
There are no specific treatments for monkeypox. However, studies have shown that the smallpox vaccine is 80% effective in preventing monkeypox. Smallpox was considered eradicated in the 1980s, and for this reason immunizations are no longer available to the general public. Few countries kept the smallpox vaccine in stock.
A specific vaccine against monkeypox has been under development in Europe since 2017. However, it is still in the testing phase. At the same time, five antiviral pills against the disease are also under development. One of them has been studied since 2009.
Although there is no specific treatment for the disease, some medications help to control it. These include cidofovir and vaccine immunoglobulin.
WHO experts said mass vaccination is not a priority. However, each country will probably need a small stock of vaccines to administer to laboratory workers and health professionals.
Until the 1980s there was the smallpox vaccine that eradicated the disease. This vaccine was created in the 17th century.
Since it first appeared in a human being in the 1970s, how has the disease evolved worldwide?
The disease occurs in humans in Africa sporadically and in occasional epidemics. The majority of reported cases occurred in the Democratic Republic of Congo.
Since 2016, confirmed cases have also been reported in Sierra Leone, Liberia, the Central African Republic, the Republic of Congo, and Nigeria, which have experienced the largest recent outbreak.
A recent 20-fold increase in incidence is thought to stem from the discontinuation of smallpox vaccination in 1980. People who received the smallpox vaccine, even > 25 years earlier, have a lower risk of smallpox.
Another reason for the increase in cases of smallpox in Africa is related to the increasing invasion by humans, of the habitats of animals carrying the virus.
Out of curiosity, we add here that studies on Egyptian mummies suggest that this disease that has wiped out millions of people at all times may have been circulating among us for at least 3,000 years.
Catarina Vilela - Nurse