Cytomegalovirus (CMV)

Cytomegalovirus (CMV)

Causative Agents

Cytomegalovirus belongs to the herpes family and is composed of a linear, double stranded DNA genome containing aproximatally 230,000 base pairs. It is believed that cytomegalovirus genome contains nearly 165 protein-encoding genes. This virus is also known as Human Herpes Virus 5 (HHV5). HCMV is among the TORCH infections (Toxoplasmosis, Othes, Rubella, Cytomegalovirus, Herpes) that are known to cause congenital anomalies. [1], [2]

Epidemiology

Infection is common with seroprevalence rates increasing steadily from 65 % among 40 to 49 year olds to 91% in those aged 80 years or older. [1],[3] Congenital CMV infection, being the most common congenital viral infection, is a significant health problem in developed countries. It is responsible for the neurodevelopmental pathological changes ,involving hearing loss. CMV infection is seen in 1% of newborn infants and causes serious life threatening problems in 10% of these infants. The morbidity rates of CMV are 90-95 % whilst the mortality rates are 4-37%. [3],[4]

Modes of Transmission

CMV infection could be transmitted via body fluids such as urine, saliva, tear, blood, sexual contact, plesantal contact, breast milk and via solid organ transplantations or blood transfusions. Transmission of this virus could easily be prevented as the ubiquitous way of transmission is contact with the body fluids, thus if hands are washed with soap after the contact, the risk of transmission can be prevented. The most common way of HCMV transmission is from mother to child in uterus or via perinatal phase (during birth). [5],[6]

Diagnosis

Diagnosis and monitoring of CMV infections can be performed with ELISA (Enzyme-Linked Immunosorbent Assay), pp65 antigen tests, viral cultures and nucleic asid tests. Antigen based methods cannot determine the viral titer and viral cultures has medium sensitivity while taking too much time and labor. CMV-DNA real-time PCR tests that involve direct detection of viral DNA have high sensitivity where specific results can be obtained fastly by this method. [7]

Annotated Bibliography

  1. 1-Mach M, Stamminger T, Jahn G, Human Cytomegalovirus: Recent Aspects from Molecular Biology, J. gen. Virol.,1989;70:3117-3146.
  2. 2-Stegmann BJ, Carey JC, TORCH Infections. Toxoplasmosis, Other (syphilis, varicella-zoster, parvovirus B19), Rubella, Cytomegalovirus (CMV), and Herpes infections, Curr Womens Health Rep. 2002;2(4):253-8.
  3. 3-Staras SAS, Dollard SC, Radford KW, Flanders WD, Pass RF, Cannon MJ: Seroprevalence of cytomegalovirus infection in the United States, 1988–1994. Clin Infect Dis 2006, 43(9):1143-1151.
  4. 4-Hodinka RL, Friedman HM,Human Cytomegalovirus, in: Balows A (ed), Manuel of Clinical Microbiology, 5'th ed, Washington: American Society for Microbiology, 1991, pp: 829-36.
  5. Adler SP, Transfusion-associated cytomegalovirus infections. Review oflnfeetious Diseases 5, 1983:977-993
  6. 5-Mandell GL, Bennett JE, Dolin R., Principles and practice of infectious diseases, 5th ed. Philadelphia: Churchill Livingstone, 2000: 1586-96.
  7. 6-Arne B Brantsaeter, Mona Holberg-Petersen, Stig Jeansson, Anne K Goplen and Johan N Bruun, CMV quantitative PCR in the diagnosis of CMV disease in patients with HIV-infection – a retrospective autopsy based study , BMC Infectious Diseases 2007, 7:127