Can Insect Bites Spread Hepatitis?
Regardless of how technologically advanced a culture is, the viral hepatitis epidemic seems to be enveloping the globe. Of particular concern to the healthcare community, the viruses that cause chronic hepatitis are the most troublesome. Chronic infection with Hepatitis B or Hepatitis C can progress to advanced liver disease, a fate involving cirrhosis, liver cancer or liver failure. A vehicle for transmitting some types of viruses, some people worry that an insect bite could pass on viral hepatitis. Since many cases of chronic viral hepatitis are incurable, hepatitis prevention takes center stage. However, even the most prepared have trouble preventing insect bites.
Because scientists know that Hepatitis B and Hepatitis C are primarily spread via blood- to-blood contact, all possible breaches of the skin have been suspected in viral hepatitis transmission. Occurring when blood from an infected person enters the body of a person who is not infected, Hepatitis B and Hepatitis C are mostly spread through:
- having unprotected sex with an infected person (more likely with Hepatitis B)
- sharing drugs, needles, or “works” when injecting drugs
- needle sticks or sharp exposures on the job
- from an infected mother to her baby during birth
- being tattooed with a contaminated needle (more likely with Hepatitis C)
Hepatitis B Virus (HBV) Transmission Risks
According to the Centers for Disease Control (CDC), those at highest risk for Hepatitis B infection include:
- Persons with multiple sex partners or diagnosis of a sexually transmitted disease
- Men who have sex with men
- Sex contacts of infected persons
- Injection drug users
- Household contacts of chronically infected persons
- Infants born to infected mothers
- Infants/children of immigrants from areas with high rates of Hepatitis B infection
- Healthcare and public safety workers with exposure to blood
- Hemodialysis patients
Hepatitis C Virus (HCV) Transmission Risks
According to the CDC, those at highest risk for Hepatitis C infection include:
- Injection drug users
- Recipients of clotting factors made before 1987
- Hemodialysis patients
- Recipients of blood and/or solid organs before 1992
- People with undiagnosed liver problems
- Infants born to infected mothers
- Healthcare/public safety workers – Low risk
- People having sex with multiple partners – Low risk
- People having sex with an infected steady partner – Low risk
Mosquito Transmission
Aside from the characteristic itching and swelling involved, fears of mosquito bites spreading disease are due to its contact with blood. The insect pierces the skin, siphons out a person’s blood then repeats on a different individual – all without sterilization in between victims. Although some say there is a theoretical risk of being infected with viral hepatitis from a mosquito bite, there are no known cases worldwide. If mosquito transmission of Hepatitis B or Hepatitis C were possible, many more millions of people would likely be affected. However, mosquito bites can transmit some viruses. Mosquito-born diseases include:
- Encephalitis
- Malaria
- Dengue fever
- Rift Valley fever
- Yellow fever
Bed Bug Transmission
Similar to a mosquito’s motive, bed bugs are also bloodsuckers. Bed bug bites can create considerable anxiety and localized and occasionally systemic reactions. Different from mosquitoes, bed bugs may be a suspected transmitter of viral hepatitis:
- HBV – Hepatitis B viral DNA can be detected in bed bugs up to six weeks after they feed on infectious blood, but no transmission of Hepatitis B infection was found in a chimpanzee model.
- HCV – Transmission of Hepatitis C is unlikely, since Hepatitis C viral RNA is not detectable in bed bugs after an infectious blood meal.
Regardless of the presence or absence of genetic material, these critters have never been proven to transmit disease. However, if concerned about the potential for getting Hepatitis B from this insect, make sure you are vaccinated. Some suggestions for detecting bed bugs include:
- Look around. Bed bugs are large enough to see.
- Look under the mattress and in the seams, in and around the bed frame and along any cracks or peeling paint in the wall or picture frames.
- Check in the cracks of any wooden furniture, particularly antiques.
- You can also spot bed bugs’ droppings, which may be tinged with blood.
Although the thought of mosquito or bed bug bites may be disconcerting, we do share this planet with them. Without invitation, these bugs break our skin and extract our blood, actions which logically cause concern. Thankfully, the risk of being infected with HBV or HCV through insect bites is just shy of impossible. So using mosquito repellant and checking for bed bugs will make you more comfortable and spare some itching, but it won’t make a difference in your susceptibility to acquiring viral hepatitis.
References:
Hwang, W. Stephen, et al., Bed Bug Infestations in an Urban Environment, Emerging Infectious Diseases, April 2005.
http://hotels.about.com, Bed Bugs, Charlyn Keating Chisholm, About.com, 2007.
www.cdc.gov, Hepatitis B: Fact Sheet, Centers for Disease Control, 2007.
www.cdc.gov, Hepatitis C: Fact Sheet, Centers for Disease Control, 2007.
www.emedicine.com, Bedbug Bites, Robert A Schwartz, MD, MPH, WebMD, 2007.
www.hepatitisc.org.uk, FAQ, Glasgow and Scotland Hepatitis C Charity, 2007.
www.whfhhc.com, Can Hepatitis B be transmitted by a mosquito or insect bite?, Centers for Disease Control, 2007.