Do STDs affect breastfeeding?

Talk with your doctor, nurse, or a lactation consultant about the risk of passing the STD to your baby while breastfeeding. If you have either chlamydia or gonorrhea, you can keep breastfeeding. If you have syphilis or herpes, you can keep breastfeeding as long as the sores are covered. Syphilis and herpes are spread through contact with sores and can be dangerous to your newborn. If you have sores on your nipple or areola (darker skin around the nipple), you should stop breastfeeding on that breast. Pump or hand express your milk from that breast until the sore clears. Pumping will help keep up your milk supply and prevent your breast from getting engorged or overly full. You can store your milk to give to your baby in a bottle for another feeding. But if parts of your breast pump that contact the milk also touch the sore(s) while pumping, you should throw the milk away.

If you are being treated for an STD, ask your doctor about the possible effects of the drug on your breastfeeding baby. Most treatments for STDs are safe to use while breastfeeding.

If you have HIV, do not breastfeed.
You can pass the virus to your baby.


http://aids.about.com/od/themostcom...eastfeeding.htm says this:
Q. Can a woman breastfeed if she suffers from genital herpes?
From Mark Cichocki,
Your Guide to AIDS / HIV.

A.
The answer is yes, breastfeeding with genital herpes is safe for your newborn. Genital herpes (herpes simplex) is spread by direct contact with the virus that causes genital herpes. This is usually through sexual contact. The virus that causes herpes is not present in breast milk, therefore your baby can’t contract herpes by breastfeeding. Keep in mind however that the virus can be spread to the baby if he or she comes in contact with a herpes lesion (for example if you had one on your breast or mouth).

http://www.pregnancy-info.net/stds_hepB_pregnancy.html
says this:

Breastfeeding and Hepatitis B
You may wonder whether it is safe to breastfeed your baby if you are infected with Hepatitis B. Studies have shown that babies who are breastfed are at no greater risk of contracting the virus than those who are bottle-fed. However, if you are thinking of breastfeeding and have Hepatitis B, be aware that cracks or sores on your nipples can increase the risk of transmitting the disease to your child.

http://www.consultdrminas.com/eng/0...fo/07_men.php#3
Says this:

Breastfeeding and STDs

If your wife or partner is breastfeeding, talk with your health care provider about the risk of passing the STD to your baby while breastfeeding. If your partner has HIV, she should not breastfeed because she can pass the virus to the baby. If your partner has either chlamydia or gonorrhea, she can continue breastfeeding. If she has syphilis, she can continue breastfeeding if the baby does not touch the sores.

Breastfeeding mothers who have trichomoniasis should know that the disease is not dangerous to the nursing baby, but the medicine used to treat it (metronidazole or Flagyl) might be harmful to your baby. If you are prescribed a single dose, stop breastfeeding for 12 to 24 hours after you take the drug. Talk with your health care provider to see if you can take a lower dose of the drug, which can be safer for your baby.


So basically breastfeeding is ok for most STDs as long as the baby does NOT come into contact with any lesions or sores. BUT if the mother has HIV/AIDS then it is a BIG NO NO.