BOSTON - Researchers have identified another way that babies can
be infected with H.I.V. - through food pre-chewed by an infected
parent or caretaker.
Although thousands of babies have been infected in the United
States over the last 15 years, pre-chewed food has been
documented as the cause of just three cases, federal
epidemiologists said here Wednesday.
But such transmission may not be so rare, Dr. Kenneth L.
Dominguez's team from the Centers for Disease Control and
Prevention said at the 15th Conference on Retroviruses and
Pre-chewing food apparently occurs among many groups in this
country and elsewhere. So transmission of H.I.V., the AIDS virus,
to infants may be an unrecognized problem in developing countries
where dental care is lacking, commercially prepared baby foods
and blenders are not available and parents and caretakers may
need to soften foods, Dr. Dominguez said in an interview.
His team said there were several reasons for reporting the three
cases, dating from 1993, for the first time. One was to make
health care providers and caregivers of infected children aware
of the potential risk of pre-chewing. Another was to ask doctors
and family members to report suspected cases to health officials
to quantify the threat.
Human immunodeficiency virus is present in saliva, but usually in
amounts too low to cause transmission. So, presumably, blood,
which has larger amounts of the virus, is also needed for
Infected chewers with inflammations or open mouth sores can pass
the virus to infants through cuts or other common teething
conditions, Dr. Dominguez said.
Although the three cases were among African-Americans born in the
United States, pre-chewing is prevalent among many ethnic and
racial groups, according to a recent national survey of infant
feeding by the C.D.C., Dr. Dominguez said.
Specific findings from the survey have not been released.
"It's likely that some cultural influences are involved, and I am
sure that people are doing what their grandmothers and aunties
did in practices carried through generations," Dr. Dominguez
Epidemiologists from the centers, working with researchers at St.
Jude Children's Research Hospital in Memphis and the University
of Miami, intensively investigated all three cases, ruling out
other causes of transmission like breast feeding, sexual abuse
and needle sticks.
The first two cases involved boys from Miami infected in the
mid-'90s. One boy's infection was detected when he was 39 months
old, shortly before his death, after previously testing negative
for the virus twice. The mother, who was infected, reported
pre-chewing food for the boy.
The second boy's mother was uninfected but lived with an infected
aunt who pre-chewed his food. He survives. In the third case, a
girl from Memphis was found to be infected in 2004 at 9 months
old after testing negative for the virus three times. Her mother
was infected and pre-chewed food for her daughter.
Genetic studies showed that the viruses isolated from the first
and third cases matched those of the mother. The second case's
caregiver died before blood samples could be obtained. H.I.V.
isolated from the caregiver's infected male sexual partner did
not match that from the boy.
Researchers will try to determine whether other dangerous
microbes like hepatitis B virus and Helicobacter pylori might be
transmitted through pre-chewed food.