Fifth disease

Also, a specific group of immunocompromised people with bone marrow failure and infected with parvovirus B19 have been shown to develop aplastic crisis.

[15] Sometimes, fifth disease can also cause serious complications, especially if the person is pregnant, has anemia, or is immunocompromised; affecting the blood system, joints or nerves.

Binding of B19V capsid to the cellular receptor globoside (Gb4Cer) results in a cascade of structural changes and subsequent signal transduction processes facilitating the entry of parvovirus B19 into the host cell.

After gaining access to the host cell, B19V binds to glycosphingolipid globoside (blood group P antigen) targeting erythroid lineage in the bone marrow.

According to a clinical microbiology review published by Jianming Qiu "Persistence of viral DNA has been detected in up to 50% of biopsy specimens of the spleen, lymph nodes, tonsils, liver, heart, synovial tissues, skin, brain, and testes, for decades after infection.

[5] After day 16, when signs of fifth disease (red rashes) and arthralgia (pain in joints) becomes apparent, specific anti B19 IgG is produced by immune cells.

[23] Typically, school children, day-care workers, teachers, and parents are most likely to be exposed to the virus making them high risk population.

The most common time for infection to spread in children causing fifth disease is during late winters and early spring, with outbreaks occurring every 3–4 years.

[24] The most common manifestation of Fifth Disease is marked by a red, "slapped cheek" look on the face and a lace-like rash on the body and limbs.

In adults, for example, joint pain caused by parvovirus B19 infection might make doctor consider conditions like the flu and mononucleosis during initial diagnosis.

Doctors may also look consider ruling out non-infectious causes like drug allergies and certain types of arthritis; which can present with similar symptoms as fifth disease.

[23] Infection by parvovirus B19 can also be confirmed by isolation of viral DNA detected by Polymerase Chain Reaction (PCR) or direct hybridization.

PCR tests are considered significantly more sensitive to detecting the viral antigen parvovirus B19 compared direct DNA hybridization.

In order to diagnose Fifth Disease in a fetus, a PCR test is done using a sample taken from the amniotic fluid surrounding the baby (otherwise known as "amniocentesis").

[21] Laboratory tests can indicate complications of infection, including anemia, liver damage, and low platelet count.

Although fifth disease primarily occurs in children and will typically resolve on its own, similar to the cold, vulnerable populations such as those who are immunocompromised, pregnant, or people with anemia are more at risk of developing complications from the disease due to their bodies compromised state making it harder for the body to fight off the virus.

However, clinical studies have shown that vaccinations for B19 carry possible additional benefits to high-risk people, such as those who are pregnant, immunocompromised, have had organ transplants, and children with anemia.

[37] Thus, much of the same NPI utilized during the COVID-19 pandemic can be used as preventive strategies for Fifth Disease, such as practice good hand hygiene, coughing and sneezing into the elbow, proper mask etiquette, and isolating when sick/contagious.

[27] Prevention strategies for pregnant women, due to the increased risk of severe complications both for them and the fetus, include increased awareness about the virus/disease to provide them with the knowledge and resources they need to take care of their health effectively, those who are at high-risk for complications should also be advised on the transmission of the virus and educated on what other safety measures they could practice to avoid areas where transmission of the disease is typically high such as childcare centers, close contact with school-age children or even close contact with someone who works with school-aged children such as teachers, and healthcare settings such as hospitals.

[27][39] In Fifth Disease, parvovirus B19 has the potential to affect various parts of the body, including the skin, heart, brain, joints, liver and more.

While parvovirus B19 is typically transmitted via respiratory secretions or hand to mouth contact, it has also been known to be passed from pregnant women to fetuses.

This analysis included a total of 89 studies covering complications in both the central and nervous system such as encephalitis, meningitis, and peripheral neuropathy.

[48] Recent research has found that children and adults who are infected with Parvovirus B19 may develop acute arthritis, and in some cases, chronic joint problems.

This is why viral infection by parvovirus B19 can be particularly harmful to people with hemolytic anemia or blood cancers, leading to a condition called pure red cell aplasia.

Individuals who have an occupation that requires close contact with infected people such as healthcare workers and teachers are at an increased risk of acquiring the viral illness.

Since transmission typically occurs through respiratory secretions, it was thought that daycare workers would be at an increased risk of infection because young children can spread saliva through drool.

[60] A 2019 meta-analysis examined rates of parvovirus B19 infection among those with Sickle Cell Disease (SCD) using IgG and IgM antibody detection.

Pooled data from Africa, Asia, and the Americas revealed a 48.8% parvovirus B19 infection prevalence among persons with Sickle Cell Disease.

[61] A 2020 literature review also supports the finding that persons with SCD, as well as those with the blood disorder beta thalassemia, are at a higher risk of parvovirus B19 infection.

[64][4] The group used electron microscopy and found viral particles with similar size and shape to parvoviruses that infect only animals.

Appearance of the distinctive "slapped-cheek" rash seen in Fifth disease
Parvovirus B19 (B19V)
Photo of a 14-month old child with fifth disease, also known as "slapped cheeks disease."