The cowpox is a zoonotic disease caused by the orthopoxvirus and although it is similar to the smallpox traditional to humans, their symptoms tend to be much more mild.
The virus got its name, hundreds of years ago, from a remark made by the English physician Edward Jenner. He discovered that the people who got the rash by touching dairy cows infected became immune not only to further cases of smallpox vaccine, but also to smallpox, because the two viruses are very similar.
Symptoms of cowpox
The cowpox infection is zoonotic (like avian influenza)in humans, primarily related to the occupational exposure to infected cattle, and occasionally other animals (usually rodents) of the orthopoxvirus genus. It is a rare disease and usually self-limiting in immunocompetent people.
The cowpox cause injury pustulosas located mainly in the fingers and hands, and sometimes also the face. The lesions develop from a single macular lesion initial that becomes papular and then vesicular, followed by a stage pustules, with edema and oozing and finally a crust, thick black. In some cases there is a rash generalized, fever and malaise with lymphadenitis, regional due to the spread of the virus.
Infection with the virus of cowpox leads to a clinical picture similar to that of the primary vaccination with vaccinia virus (the technique used by Edward Jenner in his famous experiment that demonstrated the efficacy of the vaccine against smallpox). Usually, the first lesions appear on the skin at the site of inoculation accidental and spread through autoinoculation of other body sites. The skin lesions are similar in appearance to the initial injury of vaccinia: they are firm, raised, light-colored and initially have a center warm because there is more blood in this site due to the injury caused by the injection of the vaccine.
After an incubation period of 3-7 days, the lesion becomes progressively papular and vesicular. The vesicles break off easily, leaving areas ulcerated in living flesh that eventually form a crust thick color black. The majority of affected cows will suffer the ordeñen, and if the infection spreads to the nipples, it is possible to also feel upset for being manipulated. Occasionally, the virus spreads to the legs and rarely to the vulva, and if this happens, it is likely that the cow should be slaughtered.
In Europe occur in sporadic cases of cowpox in humans, usually due to handling of infected cattle and other animals. However, the majority of human infections are acquired from domestic cats that have contracted the virus from rodents of the forest. The transmission from cat to human is rare, but constitutes a serious problem for people with weak immune systems, such as babies and adults who are immunocompromised. It is advisable to wear disposable gloves when preparing food, cleaning up pet waste and manipulate other animals for these people.
Diagnosis
The cowpox is caused by a virus of the orthopoxvirus genus, the same family as the deadly smallpox virus. In Europe occur sporadic cases of cowpox in humans, mostly related to contact with infected animals (rodents and cats). The virus causes lesions pustulosas localized in the fingers and hands, and is usually self-limiting in immunocompetent people. It is more serious for those receiving immunosuppressive therapy (such as patients with renal transplants or those treated for rheumatoid arthritis) and can cause a serious disease with skin lesions disseminated, pneumonia, or death.
The first symptoms of the disease are a painful redness in one of the udders that makes it very difficult for the milking. In a few days, this becomes a papule orange, which then becomes a scab. A new skin beneath the crust that help to lift it, forming a horseshoe or ring around the nipple. The affected area is painful and often swollen, but this improves with time. Within a month, all the scabs usually fall off, leaving areas in the living flesh that heal. As a result, the cow may be less productive and the nipple damaged must be rebuilt.
The diagnosis of smallpox vaccine is made by the detection of the DNA of the virus of smallpox vaccine in the blood by polymerase chain reaction of the polymerase. The diagnosis is confirmed after a comprehensive clinical assessment and the correlation of the results of special studies on tissues (if needed).
The differential diagnosis should include cutaneous anthrax, cat scratch disease and tularemia because these diseases have similar symptoms.
Treatment
The infection is usually self-limited and patients may recover without significant morbidity, however, to spread the disease can cause discomfort and general malaise, therefore, it is recommended to rest and bring rest to recover.
In the case of cows that have the disease, it is recommended to keep them in quarantine, separate from other animals to prevent the spread to other healthy animals, as the risk of contracting the infection can be minimized by not allowing the direct contact of healthy animals with other infected animals.
There is No specific treatment for the disease. Antibiotics are used for bacterial infections and, sometimes, it is prescribed acyclovir to reduce the severity of the disease and increase the likelihood of forming scabs quickly. However, these medications are not always available and can be expensive.
Also in the case of human beings it is recommended to wash your hands regularly to prevent the spread of the virus between humans and animals; this is particularly important for those working with zoonoses such as rabies, eczema, and Darier's disease.
Prevention
The prevention of smallpox bovine focuses on taking necessary measures to prevent the introduction of new strains of the disease from other countries, as well as prevent the disease from traveling and spreading the stable when its presence has been detected.
In order to avoid the disease among other countries and to spread, the main recommendation is to contact the competent health authorities when cases are known of cowpox, since the authorities are in charge of ruling out infections massive and prevent the spread of the disease. Maintain standards of biosecurity strict is another indiaciones to follow; the veterinary field, responsible for the control of diseases in your region, or county, shall be active in pro to control potential sources of contagion.
When the measurements have been taken necesiarias to prevent the spread, and anyway, the herd contracted cowpox, the recommendation is the sacrifice of cows infected to prevent the disease to pass to healthy animals and compromise the integrity of the flock. When it is not possible to slaughter of infected animals, you should take measures of isolation and quarantine of animals with the disease (as it is recommended in the equine infectious anemia) to prevent its spread.
