AIDS Virus Infection in 2 Groups Is Lower in State

Two new studies indicate that AIDS virus infection rates in childbearing women and newborns in California are much lower than those found in other areas, including New York and Massachusetts.

A study by the state Department of Health Services suggests that only 123 to 220 of the more than 500,000 babies born in California last year are likely to have been infected with the human immunodeficiency virus. The results of the anonymous testing also suggest that fewer than one in 1,000 mothers statewide is infected with HIV, the virus that causes acquired immune deficiency syndrome.

Preliminary results of a related Los Angeles County study suggest that the rate of infection in childbearing women may be even less--about four in 10,000. More detailed geographic data to pinpoint HIV infections within California and Los Angeles is not yet available.

“It is very good news,” said Dr. Kenneth W. Kizer, the state health director. “It is a much lower rate than any of us had anticipated.”

The results indicate a “tremendous opportunity” to prevent further spread of the AIDS virus into what is generally regarded as a low-risk group--heterosexual women of childbearing age, according to Dr. Peter Kerndt of the Los Angeles County Department of Health Services.

That spread is primarily thought to occur--as it has in New York City and Newark--through intravenous drug use and sexual transmission of HIV to women who are the sexual partners of intravenous drug users or bisexual men. By preventing the spread of HIV to childbearing women, the transmission of the virus to newborns can also be prevented.

Recent studies have shown that 21 in 10,000 childbearing women are infected with the AIDS virus in Massachusetts and 74 in 10,000 are infected in New York, compared to 8.3 in 10,000 as found in the California study.

The explanation for the differences between the two coasts is not entirely clear. They may include differences in the interactions between gay males and intravenous drug users as well as differences in the needle-sharing practices of addicts. Sharing of contaminated drug injection equipment is a very effective mechanism of spreading HIV, hepatitis and other diseases.

In an interview, Kizer said that while the new data is encouraging, increased voluntary HIV testing for pregnant women remains a priority, particularly for those who may be at high risk of carrying the virus.

“The message to the individual continues to be the same, whether it is safe sex and monogamy or testing. . . . The fact that population-wise we are not in as bad a way as some other places does not lessen the need for individuals to make informed and safe decisions,.” Kizer said.

Most of the country’s 16,800 reported AIDS cases in heterosexual intravenous drug users and the 1,400 cases in children have occurred on the East Coast. Between 1981 and the end of January, there had been 649 intravenous drug use cases and 112 pediatric cases reported in California. Half of the pediatric cases involved transmission of HIV from infected mothers and half involved transmission from contaminated blood products.

Kizer declined to credit the low infection rate in California as “indicating something about the success of our educational programs” because “I just don’t think we have the data to show it.”

A positive AIDS antibodies test on a baby indicates that its mother is infected with HIV but does not necessarily mean that the baby is also infected. Current evidence suggests that only 30% to 50% of the babies who test positive are carrying the virus. The other babies test positive simply because they receive the antibody proteins from their mother; the proteins are subsequently shed over a period of several months.

Answers Sought

Scientists are still trying to determine why some of these babies become infected and others do not.

State heath officials anonymously tested blood samples for all live births in California during July, 1988. Of 43,301 samples tested, the presence of AIDS antibodies was confirmed in 36 babies, or 8.3 in 10,000 samples.

From this result, Department of Health Services officials estimated that between 410 and 440 babies were born to HIV-infected mothers in 1988 and between 123 and 220 babies are likely to have become infected with the virus.

The testing is possible because, under the state newborn screening program, the heel of each baby is stuck with a needle before hospital discharge and spots of blood are collected on a piece of filter paper to be screened for three inherited, but preventable, forms of mental retardation--galactosemia, hypothyroidism and PKU, or phenylketonuria. Similar sampling is mandated for babies born at home.

The newborn screening program prevents a total of 120 to 130 mental retardation cases a year--which is similar to the number of new HIV infections estimated to occur in the state each year.

Kizer said he does not currently support mandatory non-anonymous HIV testing for all newborns, as is done for the other diseases, because there are no proven treatments that need to be “implemented immediately.” But he added: “If something should change where a treatment were to come along . . . then I think we would obviously rethink that.”

Los Angeles County is separately testing 9,400 consecutive specimens of umbilical cord blood samples from babies born at four large hospitals between early September and early December, 1988, said Kerndt, the medical director of the county’s AIDS epidemiology program. Anonymous tests on 7,200 specimens have been completed; the presence of AIDS antibodies was confirmed in three babies, or 4.2 in 10,000 samples.

Kerndt declined to identify the hospitals, but said that they included the facilities in the county where HIV-infected mothers were most likely to be cared for.

Dr. George Rutherford of the San Francisco Department of Public Health said that it would not be surprising if infections in childbearing women turned out to be more common in San Francisco because per capita “there is more HIV infection (here) than anywhere else in the state.”

Between 15% and 20% of the 10,000 to 12,000 active heterosexual intravenous drug users in San Francisco are believed to carry the AIDS virus, Rutherford said. By comparison, only about 3% of the estimated 80,000 to 120,000 active intravenous drug users in Los Angeles County are thought to be infected, according to Kerndt.

In some large East Coast cities, such as New York City and Newark, the situation is much different. Recent studies show that as many as 60% of New York City’s estimated 250,000 intravenous drug users may carry the AIDS virus and that one in 77 babies born in the city has AIDS antibodies.

Over the next several months, California health officials expect to complete testing on an additional 85,000 newborn blood samples from August and September, 1988, according to Frank J. Capell, an epidemiologist with the state Office of AIDS. The results for July through September will be analyzed by age and race of the mother, and the county and ZIP code of the mother’s residence.

Similar data will also be collected and analyzed for July through September of this year. The cost of the ongoing research project is about $800,000 a year.

As of Feb. 6, 85,590 AIDS cases and 48,957 deaths had been reported in the United States. As of the end of January, 17,521 AIDS cases and 10,431 deaths had been reported in California.

HIV INFECTIONS IN CHILDBEARING WOMEN

The California Department of Health Services and the Los Angeles County Department of Health Services have released data on the rate of human immunodeficiency virus infections in childbearing women and newborns. Current medical evidence suggests that between 30% and 50% of infants born to HIV-infected mothers will become infected with the virus.

The rates for California and Los Angeles are much lower than rates for other areas of the country for which comparable data is available. The statistics are based on tests of tens of thousands of blood samples.

PERCENTAGE OFCHILDBEARING TIME PERIOD WOMEN INFECTED California July 1988 0.083% Los Angeles Fall 1988 0.042% Massachusetts 1986-1987 0.21% New York 1987-1988 0.74% New York City 1987-1988 1.30%

Here is how the rate of HIV infections in childbearing women compares to data for other population groups in California.

TIME PERIOD PERCENTAGE INFECTED Childbearing Women July 1988 0.083% Blood Donors Summer 1988 Female 0.002% Male 0.022% Military Recruits 1985-1988 Female 0.076% Male 0.183%