Not sure if this has been posted here before, but even if so, it is worth the re-hash.

Before the Bris: How to Protect Your Infant Against Herpes Virus Infection Caused by metzitzah b’peh

Circumcision has health benefits. Recently, however, the Health Department has documented several cases of herpes infection in newborns after circumcisions that included metzitzah b'peh. Metzitzah b'pehis a religious practice performed by some mohelim (religious circumcisers) in the Jewish community. Some of these infants became seriously ill. One baby died, and another suffered brain damage.
Communicable Disease

Because there is no proven way to reduce the risk of herpes infection posed by metzitzah b'peh, the Health Department recommends that infants being circumcised not undergo metzitzah b'peh.

To help you protect your baby, we want to make sure that parents understand the risk of metzitzah b'peh BEFORE the day of the bris, while there is time to explore other options.
How metzitzah b'peh spreads herpes

In metzitzah b'peh, the mohel places his mouth on the freshly circumcised penis to draw blood away from the cut. If the mohel is infected with oral herpes (as most adults are), metzitzah b'peh can expose the infant to the herpes virus. While severe illness associated with this practice may be rare , there is a definite risk of infection.

Oral herpes spreads easily through saliva, especially when saliva touches a cut or break in the skin, such as during metzitzah b'peh.Most people with oral herpes don't know they are infected and don't have symptoms. Even without symptoms, however, people can spread the infection.

Because the immune system of newborns is not developed enough to fight serious infection, herpes infections pose grave risks to infants.
There is no proven way to reduce the risk of metzitzah b'peh

Although a mohel may use oral rinses or sip wine before metzitzah b'peh, there is no evidence that these actions reduce the spread of herpes. A mohel who takes antiviral medication may reduce the risk of spreading herpes virus during metzitzah b'peh, but there is no evidence that taking medication eliminates this risk.
Many mohelim do NOT practice metzitzah b'peh

While some religious authorities consider metzitzah b'peh the only acceptable way to draw blood away from the circumcision cut, others use different means. For example, some mohelim use a glass tube – or a glass tube attached to a rubber bulb – to suction blood in a way that does not include contact between the mohel's mouth and the baby's cut. Others use a sponge or sterile gauze pad to wipe blood away. Unlike metzitzah b'peh, there is no evidence that any of these practices causes infection.
Ask about metzitzah b'pehBEFORE the day of the bris

Some parents whose infants had metzitzah b'peh say they did not know the mohel would perform it. The Health Department recommends that parents ask the mohel several days before the bris if he practices metzitzah b'peh. This will give time to talk to your doctor and consider other options for circumcision.

T.J.B.

http://www.nyc.gov/html/doh/html/std/std-bris.shtml