Dr K K Aggarwal

eMedinewS Editorial

Exposure to HIV, Hepatitis B and or Hepatitis C infected blood

Although more than 200 different diseases can be transmitted from exposure to blood, the most serious infections are hepatitis B virus (HBV), hepatitis C virus (HCV), and HIV. Co infection with HIV and hepatitis C infection or HIV with hepatitis B infection is also common since all three infections share similar routes of transmission. Approximately 30 percent of patients who are HIV infected are also co infected with HCV and 10% with chronic hepatitis B infection. The prevalence also depends on the route of transmission. Hepatitis C virus seroprevalence in HIV infected patients is seen in up to 73 % in intravenous drug users and 4 % in patients considered to be at low risk.

Injection drug users usually acquire hepatitis C virus before HIV infection while men who have sex with men typically are infected with HIV before they acquire hepatitis C virus infection. Hepatitis C virus is transmitted efficiently via percutaneous routes, so seroprevalence rates are highest in intravenous drug users. Injection drug use is currently the leading route of HCV transmission.

Transmission

In order to be exposed to a blood-borne pathogen, one must have contact with virus containing blood, a visibly bloody fluid (sputum or urine containing blood), or another bodily fluid (semen or vaginal secretions). The blood or fluid must come in direct contact with some part of the body. A virus can enter the body through the bloodstream, open skin, or mucous membranes (eye, mouth, or genitals). Contact with intact skin (without new cuts, scrapes, or rashes) poses no risk of infection. Thus, exposure to a blood–borne pathogen is possible after a skin injury such as a needle stick or cut with a sharp object or contact with a mucous membrane (including exposure through sexual intercourse, especially if an ulcer is present or vaginal tissues are injured) or non intact skin.

Hepatitis B virus (HBV) is the most infectious virus that can be transmitted through the blood or bodily fluids. A healthcare worker who is stuck with a needle containing blood infected with hepatitis B virus has between 6 to 30% chance of developing hepatitis B. The risk of hepatitis C virus and HIV in the same situation is 1.8 and 0.3%, respectively. Hepatitis B virus gets transmitted by percutaneous and mucosal exposures and human bites. It has also been transmitted by fomites such as finger stick blood sugar check, multi dose medication vials, jet gun injectors, and endoscopes. HBV can survive on counter tops for seven days and remain capable of causing infection. Transmission of hepatitis C virus from blood splashes to the conjunctiva has been described. Hepatitis C virus has been demonstrated to survive on environmental surfaces for at least 16 hours but not 4 or 7 days.

Dr KK Aggarwal
Editor in Chief