1. If a mother is HIV positive, we have to start antiretroviral drug (zidovudine) to baby for 6 weeks prophylactically. Will this drug also not prevent HIV virus load transmitted from mother to baby via breast milk? So why cannot we advise breastfeeding to such babies safely?

2. As pediatricians we are often called in the operation theatre and labor room for resuscitation of a baby. In this context, I seek the following clarification:

1. What should be done if the HIV report of mother is not available while resuscitating the baby?

2. On rare occasions we have to resuscitate the baby by giving either mouth to mouth breathing or through endo-tracheal tubers (Oxygen clinder is empty and Bagmask is not functioning). Afterwards we come to know that the mother is HIV positive. In such case what is the chance of getting infection to the medical personnel involved in resuscitation?

Vidya Prakash Fadnis,
Pediatrician,
Yashvantrao Chavan Hospital,
Pimpri, Pune 411 019,
Maharashtra, India.

Dr. Fadnis has raised two important issues regarding HIV infection in infants. The first relates to transmission of HIV via breastfeeding and the second to the risk of acquiring infection from an infant born to an HIV-infected mother.

1. Prophylactic zidovudine has been shown to be useful in two situations. The first is in prevention of mother-to-child transmission of HIV. The second is in prevention of trans-mission of HIV following a percutaneous or mucous membrane exposure to HIV in health care workers (HCWs). In both these situations, the antiviral drug is started soon after exposure and given for 4-6 weeks after the exposure has ceased and has been shown to reduce, but not completely prevent, trans-mission. Since a significant proportion of perinatally infected infants are exposed in the intrapartum period, 6 weeks of zidovudine starting soon after birth can reduce transmission by about 30-50%. With breastfeeding, the risk of transmission of infection is greatest during the first few months after birth but persists for as long as the breastfeeding is continued. Thus, for zidovudine to be effective in preventing transmission of HIV infection it must be given throughout the period that the infant is breastfed and for 4-6 weeks after feeding is discontinued and not just for 6 weeks after birth. The protective efficacy of such a strategy is not known, but is unlikely to be 100%. Also, such treatment would be expensive. Parents who can afford prolonged treatment with zidovudine could usually provide safe alternative feeds for the baby. This would be a much safer option.

However, this is not to say that breastfeeding cannot be attempted in infants born to HIV-infected mothers. A recent study from South Africa has shown that exclusive breast feeding (i.e., no other oral feed, including water) is not associated with a higher risk of transmission of infection as compared to never breastfed infants. Thus, when artificial feeds are not feasible, one option would be exclusively breastfeed the infant (bearing in mind the strict definition of exclusive breastfeeding) for 3-4 months, followed by early weaning, so as to limit the duration of exposure to breast milk to the period when it is crucial to the health of the infant.

2. Health care workers (HCWs) are at a higher risk for acquiring HIV infection from patients. This is true not only for HIV but also for other blood-borne pathogens such as hepatitis B and C viruses (HBV and HCV). The risk of acquiring HBV and HCV are 10-100 times greater than HIV. Most patients infected with HIV, HBV and HCV have no symptoms or signs of infection. Moreover, serological tests may miss a small proportion of patients with infection and may not identify as yet unknown pathogens. Therefore, it is extremely unwise to take precautions only when the patient is known to be HIV positive. It is much better to assume that all patients are infected with one or more blood borne pathogens and take precautions for all patients (Universal Precautions). HIV, HBV and HCV can be acquired by percutaneous or mucous membrane exposure to infected body fluids. In the case of pregnant mothers and infants, this would include blood and amniotic fluid. Those conducting the delivery should wear gloves, mask and protective eye-wear (goggles). Extreme care should be taken to minimize the chance of a needle-stick injury by proper handling and disposal of needles and sharps. The details of universal precautions and their applications have been published earlier(2,3).

Most known transmission of HIV from patients to HCWs is through percutaneous injury with a hollow needle containing contaminated blood. Transmission by this route is also extremely low and estimated to be 0.3%. The risk of acquiring infection from mouth-to-mouth resuscitation is not known but likely to be much lower. However, there are other pathogens that may be transmitted via this route. Hence, it is wise to take precautions even during this procedure. As far as possible, mouth-to-mouth respiration should be avoided. Ensure that a working bag and mask is always available. Also keep a mouthpiece for the rare occasions when the bag and mask malfunctions.

Should exposure occur despite all precautions, post-exposure chemoprophylaxis will reduce the chance of infection. This is usually recommended following percutaneous or mucous membrane exposure to blood and body fluids containing blood. Zidovudine alone is estimated to reduce the risk of transmission by 80%. However, the CDC currently recommends 2 or 3 antiretroviral drugs (depending on the magnitude of the exposure) for 4 weeks starting soon after exposure. Details of the prophylaxis have been published(4) and are available via the Internet at the CDC website (http://www.cdc.gov/ncidod/hip/).

Thomas Cherian,
Professor,
Department of Child Health,
Christian Medical College and Hospital,
Vellore 632 004, Tamilnadu.
E-mail: [email protected]