Parvovirus B19 primarily attacks children, but also adults. Half of the cases are asymptomatic or mildly symptomatic. However, parvovirus B19 can be very dangerous, especially for pregnant women. Find out how this parvovirus is infected, what diseases it causes and how to treat them.

Parvovirus B19is a single-stranded virus, the only one in the parvovirus family that is dangerous to humans. It mainly affects school-age children (5-14 years old) and in most cases causes mild disease, giving permanent immunity for life. Seropositivity (the presence of antibodies against B19) increases with age. From 5-10 percent in children 2-5 years old to 60 percent in adults in their 30s. However, sometimes parvovirus B19 infection can lead to serious complications. It can also be very dangerous for pregnant women. He is the culprit of diseases such as:

  • contagious erythema
  • thrombocytopenia
  • leukopenia
  • maculo-haemorrhagic syndrome of gloves and socks
  • polyarthritis syndrome
  • aplastic breakthrough
  • neonatal anemia

There is no vaccine against B19 parvovirus.

How does Parvovirus B19 become infected

Parvovirus B19 infection occurs primarily through droplets, sometimes also as a result of transfusing infected blood or blood products. It may take several to several days from the moment of infection until the first symptoms appear.

In an infectious erythema, when the first symptoms resembling a cold appear, the patient becomes infected. When a rash appears, the person is "safe" for those around them. In the case of maculo-haemorrhagic syndrome with gloves and socks, the patient still has a rash and continues to infect. However, in the aplastic crisis, the patient becomes infected a week before the appearance of the symptoms of the disease, when he does not even know that he is sick.

A newborn can be infected by a mother who is a carrier of B19, moreover, the virus passes through the placenta to the fetus, so infection can also occur in utero, which is especially dangerous.

What diseases can parvovirus B19 cause

The most common disease caused by parvovirus B19 iscontagious erythema , also calledthe fifth disease. The name comes from the fact that in the past, four childhood diseases with rashes were known - measles, scarlet fever, rubella, and the fourth Dukes' disease - and contagious erythema was considered the fifth. Let us add that erythema cases are seasonal - from late winter to early spring, similar to smallpox.

Infectious erythema - symptoms

In the first phase of getting sick, i.e. from a few to a dozen or so days, there are flu-like symptoms, so:

  • fever
  • chills
  • sore throat
  • qatar
  • muscle aches
  • puffiness
  • general weakness, fatigue
  • sometimes upset stomach

Then there is a rash on the face, which due to its specific location is referred to as " slapped baby syndrome ". In the following days, it may spread to the torso, thighs and buttocks and last for about 2-3 weeks. The rash disappears without leaving any scars.

Diagnosis is made on the basis of genetic testing for the genome of parvovirus B19 DNA (PCR method) or testing for the presence of parvovirus B19 specific IgM antibodies (ELISA method). Remember that newborns are tested for IgM antibodies, not IgG, as the baby uses maternal IgG antibodies by the end of the first year of life.

The disease, in its classic, uncomplicated form, does not require special therapy, it is recommendedhome treatment , consisting of rest, hydration, or possibly lowering the temperature. Parvovirus B19 infection rarely has harmful consequences for a child. However, if a pregnant woman is sick, it is necessary to monitor the fetus because parvovirus B19 is dangerous for her.
It also happens that infectious erythema leads to complications. Then the patient may appear:

  • inflammation of the blood vessels
  • myocarditis
  • inflammation of the peripheral nerves
  • nephritis

which require specialist treatment.

Maculopapular haemorrhagic syndrome of gloves and socks

This is the version of erythema that occurs in older children, teenagers, and adults. The rash appears on their feet and hands only, and the patient looks as if he was wearing gloves and socks. These changes disappear after 1-2 weeks. The rash is accompanied by:

  • fever
  • general nerfs
  • lack of appetite
  • muscle aches
  • joint pain
  • headaches

This may be followed by swelling, pain in the limbs and itching. Sometimes children develop a complication of arthritis with swelling, soreness and limitedmobility of the small joints of the hands and feet, as well as knees and elbows, but without the destruction of the articular cartilage (polyarthropathy syndrome).

Often, tests show accelerated sedimentation of red blood cells (ESR) and elevation of the rheumatoid factor. Then treatment with non-steroidal anti-inflammatory drugs should be initiated. Symptoms should disappear after a few to several months. Otherwise, the diagnosis is juvenile arthritis. In adults, arthritis can appear without a rash.

Other parvovirus B19 diseases

In immunocompromised people, e.g .:

  • after organ transplants
  • treated with immunosuppressants
  • after chemotherapy
  • with red cell diseases

Parvovirus B19 infection can lead to chronic anemia (anemia) and sometimes even severeaplastic crisis . His symptoms are:

  • fever
  • vomiting
  • pale mucosa
  • mild jaundice

Parvovirus B19 infection during pregnancy

It should be emphasized thatgetting sick in a pregnant womanmay not have any effect on the fetus, and even if the virus penetrates into the child's body, it does not necessarily mean that the child will get sick. However, there is a risk of serious complications, therefore it is imperative tomonitor the condition of the fetus(USG), because this allows timely treatment to be started, including: onintrauterine blood transfusion . Transfusion significantly reduces the risk of intrauterine death.

Parvovirus B19 during pregnancy can cause:

  • acute fetal anemia
  • fetal thrombocytopenia
  • fetal hypoxia
  • fetal swelling
  • child's intrauterine myocarditis
  • intrauterine fetal death - most cases of miscarriage due to parvovirus B19 infection occur in the first trimester of pregnancy
  • visual impairment, e.g. missing iris, lens, corneal damage
  • neonatal hepatitis
  • hydrocephalus
  • developmental delay

It is worth emphasizing thatthe risk of developing severe complicationsrequiring intrauterine treatment is practically absent 12 weeks after seroconversion (production of antibodies in response to infection) or after 21 weeks of pregnancy. Pregnant women diagnosed with Parvovirus B19 infection are treated with anti-B19 monoclonal antibodies. Future mothers require close supervision and should be screened weeklyultrasound (USG) of the fetus.

If Parvovirus B19 infection occurs inearly pregnancy , it can manifest as a widening of the nape fold, similar to genetic defect syndromes.

Symptoms of parvovirus B19 infection are not specific and can be confused with a "common" cold, so women planning pregnancy or already pregnant should perform a test for the presence of antibodies against this virus in the IgM and IgG class.

IgG will be evidence of a previous infection and the acquisition of immunity against parvovirus B19 (half of pregnant women have acquired, permanent immunity to infection), while a positive IgM result speaks for a recent infection and must be subject to continuous monitoring of pregnancy.

Infection of a pregnant woman with parvovirus B19 shortly before delivery may result in congenital infection of the newborn, associated with anemia, thrombocytopenia and hypoalbuminemia.

Parvovirus B19 infections should be differentiated from rubella . It sometimes happens that pregnant women are certain that they had rubella in their childhood, although it could be an infectious erythema - that is why it is so important to perform appropriate tests, because pregnant rubella is dangerous.

Worth knowing

Animals have a disease called parvovirus, caused by other parvoviruses. For example, in dogs the disease is caused by canine parvovirus. It is a serious disease that mainly affects puppies up to six months of age. It is characterized by severe, debilitating, sometimes bloody diarrhea, abdominal pain, fever and general weakness. Treatment consists of electrolytes, glucose, antibiotics, boosters and canine parvovirus serum. Young cats, on the other hand, can develop panleukopenia (feline typhus, feline distemper), which is caused by the panleukopenia virus, closely related to canine parvovirus, and also manifests itself in the digestive system. However, animals can be protected from infection by vaccines. Parvovirus can also affect pigs, foxes, waterfowl - ducks, geese (goose parvovirus).

Category:

Infectious diseases