Parvoviruses

 

Parvovirus B19 is the cause of erythema infectiosum (fifth disease) in young children. The infection is characterised by fever and rash with erythema of the cheeks (“slapped cheek' appearance); there is usually a lacy pink or morbilliform rash on the limbs and trunk. Parvovirus is particularly associated with the production of arthropathy; this is much more frequent in adults, especially women, in whom primary parvovirus B19 infection can produce polyarthritis, in about half of cases without erythema infectiosum. Parvovirus B19 is tropic for erythroid progenitor cells (the erythrocyte P antigen is the virus receptor). Infection causes erythroid arrest, which can result in aplastic crises in individuals with sickle-cell disease, and other diseases with high red-cell turnover. Intrauterine infection from infection in pregnancy can result in hydrops fetalis, due to fetal anaemia from infection of fetal erythroid progenitors. Infection in immunodeficient subjects can cause chronic anaemia associated with persistent B19 infection; the virus can be cleared in these patients by administration of intravenous immunoglobulin (which contains neutralising antibody). Diagnosis is by detection of IgM antibody to B 19, or of virus DNA in blood.

Concepts of infection
Major manifestations of infection
Principles of management of infection
Diseases due to viruses
DNA viruses
Diseases due to chlamydiae
Diseases due to rickettsiae
Diseases due to bacteria
  • Streptococcal infections
  • Staphylococcal infections
  • Corynebacterial infections
  • Bacillus infections
  • Bordetella infections
  • Salmonella infections
  • Food poisoning
  • Dysentery
  • Other true bacterial infections
  • Mycobacterial infections
Diseases due to spirochaetes
  • Leptospira infections
  • Borrelia infections
  • Treponema infections
Diseases due to fungi (mycoses)
  • Cutaneous fungal infections
  • Subcutaneous fungal infections
  • Systemic fungal infections
Diseases due to protozoa
Diseases due to helminths
  • Trematode (fluke) infections
  • Cestode (tapeworm) infections
  • Nematode (roundworm) infections
  • Zoonotic helminth infections
Diseases due to arthropods
Sexually transmitted diseases
  • Sexually transmitted bacterial diseases
  • Sexually transmitted viral diseases
  • Miscellaneous conditions