Re: Question that just occured to me....

July 4, 2004

This issue has been researched, and the consensus among scientists is that it

would be very rare to get hepatitis C from mosquitoes.

http://www.health.gov.au/pubhlth/strateg/hiv_hepc/hepc/

http://www.phaa.net.au/policy/Hep%20CF.htm

And this from the Gastroenterology Forum from Pho M.D.:

The transmission of hepatitis C is one of the most controversial and emotional

issue surrounding hepatitis C. This is in part, because in up to 10 to 40%

(depending upon the study) of patients, we’re not sure how they were exposed to

the virus. However, on the other hand, we do know a lot about transmission and I

think we should try to examine the considerable information at hand. First, of

all, I’m going to assume that everyone is asking about hepatitis C and to a

lesser degree hepatitis B. Brown does not specifically refer to viral

hepatitis but I’ll assume that’s what he is talking about.

Hepatitis C is a very hard virus to transmit and requires blood to blood

contact. The two most common ways the virus is transmitted in this country is by

intravenous drug use and by transfusions. In my practice, I see about two

patients who received it through drugs for every one patient who received it

through a transfusion. Other potential ways of getting it are tattoos, body

piercing, intranasal cocaine, exposure as a fetus or during birth, occupational

exposure (needlesticks for health care workers) and finally through sex.

Let me talk specifically about sexual exposure. Hepatitis C is not easily

transmitted through sex because even here blood to blood contact appears to be

required in that the hepatitis C virus has never been found in semen or cervical

secretions. It turns out that the main risk factor for sexual transmission of

hepatitis C is having multiple sex partners. In fact, two people involved in a

monogamous relationship have a very low chance of giving each other the

hepatitis C virus even if they have been sexually active for 20 to 50 years. One

explanation for this (that has not been proven) is that people who have multiple

sex partners are at a greater risk for sexually transmitted diseases and that

venereal sores can allow blood to blood contact. Therefore, I’m certainly not

surprised that R.J.’s wife is negative for the hepatitis C virus. Now it is

critical to stress that this is not quite as true for hepatitis B which is much

easier to transmit through sexual activity. Certainly, anyone

who has a partner who has hepatitis B, should strongly consider the hepatitis B

vaccine.

I’ll try to address some of the specific questions and then I’ll talk about

mosquitoes because that is on everyone’s mind. First of all you could not obtain

hepatitis C from eating a salad into which someone with hepatitis C had bled.

Hepatitis C and B are not spread by oral ingestion. Secondly, I’m not certain

how long either hepatitis B or C remain infective on say a needle or razor. I

have periodically tried to find that information and have not been able to. I

would assume anything that potentially has blood on it is potentially infective

no matter how old the blood is. Thirdly, we do feel hepatitis B and C can be

spread by shared toothbrushes or razors because they can get blood on them and

then mix with the blood of someone else who might use them. We feel it is

critical that patients with viral hepatitis not share these things. I would also

imagine that if someone in a hair salon could spread hepatitis C if they used

razors or some other instrument that might have blood on it

repeatedly on many customers. I am not specifically aware of a case of this.

Finally, I am not aware of any mass epidemics in this country involving vaccines

given in the military or elsewhere. There certainly is a tragic situation where

many hemophiliacs received both hepatitis C and HIV/AIDS through blood products

they take to help them clot. There was also a case of an epidemic in Ireland as

a result of a contaminated blood product given to pregnant women.

Now finally, let me talk about mosquitoes. It has been postulated that

mosquitoes and other insects can transmit the virus. What I can tell you is that

hepatitis C does not grow, survive or replicate in mosquitoes. It is possible

that if a mosquito bit someone with hepatitis C and then almost immediately bit

someone else, the mosquito could potentially transmit the virus but there is no

evidence that any significant number of individuals have obtained hepatitis C

this way.

Finally, I wanted to make a comment to Brown. I do not know why so many

individuals at his plant were found to have hepatitis C (again I assume we are

referring to hepatitis C) but I would point out that it does not mean they all

obtained hepatitis C at the same time. The infection could have been obtained at

anytime because hepatitis C often remains without symptoms for decades or even

longer. I wonder, if everyone was simply tested for hepatitis C at or about the

same time. Finally, I do want to stress that I agree with everyone that more

research needs to be done and more research is being done. However, I do not

want people in the population at large who are not exposed to high risk

behaviors to think they are likely to suddenly come down with one of these

viruses for no obvious reason.

I hope this information is helpful to you. If you have any additional questions

or concerns, you can post them through MEDHELP or contact us directly at Henry

Ford. The direct number to our liver clinic is: . At Henry Ford,

we have a very active group of hepatologists with a strong interest in the care

and research of hepatitis C.

This response is being provided for general informational purposes only and

should not be considered medical advice or consultation. Always check with your

personal physician when you have a question physician when you have a question

pertaining to your health

The above is from the following URL:

http://www.medhelp.org/perl6/gastro/archive/2800.html

Colleen

Tony wrote:

What's the deal with mosquito's? I like to go camping with friends,

but what if I'm bitten by a mosquito, who then snacks on someone else?

Is this a possible form of transmission? If so, should I be contacting

my past camping friends to have them get tested?

Curious,

Tony

Birth and Death are the two noblest expressions of bravery. -

---Kahlil Gibran

For what is it to die, But to stand in the sun and melt into the wind? And when

the Earth has claimed our limbs, Then we shall truly dance.

--Kahlil Gibran

July 4, 2004

Tony,

That's a really good question! Now you have me curious as well. I mean,

mosquito's have been known to pass on other virus/diseases here in Australia

(Ross River Fever is the first that comes to mind). I don't know what the

answer is. Perhaps they could be a culprit, especially in people who honestly

don't know where they got the virus from i.e never had a blood transfusion, did

IV drugs or had other risky situations like dirty tattoo needles. My partner

Daryl is in that group, we just can't figure out where it came from. His Gastro

has told us that there is a catagory of people who spontaneously contract Hep

from who-knows-where. Perhaps Mozzies are the culprit. It's definitely worth

further investigation, that's for sure.

anne

Question that just occured to me....

What's the deal with mosquito's?

July 4, 2004