VII. The text will give some information about the results of

national population-based survey initiated to measure human immunodeficiency virus infection in women. Read the text through and make a summary using these statements as a plan.

1. The number of seropositive women.

2. Race-specific rates obtained from the survey.

3. The scientific value of population-based survey.

PREVALENCE OF HIV INFECTION IN CHILDBEARING WOMEN IN THE UNITED STATES

The occurrence of 6000 births to HIV-seropositive women in a single year implies that thousands more reproductive-age women in the United States are also infected with HIV. In 1989, about 7% of women aged 15 to 44 years gave birth to live infants. Social and demographic character­istics of childbearing women differ from those of women who are unable or choose not to bear children; because some of these differences may also be associated with risk of exposure to HIV, it is uncertain whether HIV seroprevalence in childbearing women is higher, lower, or the same as in other reproductive-age women. However, if H IV prevalence rates are sim­ilar among all women in this age group, as many as 80000 reproductive- age women could be currently infected with HIV. Although most of these women reside in metropolitan areas along the Atlantic coast, others are found outside major cities and in all regions of the country.

Race-specific rates from this survey consistently reveal substantially higher HIV sero-prevalence in black women, a pattern resembling that observed among women and children with AIDS. Most women acquire HIV-infection through intravenous drug use or sexual contact with an infected partner, most often a male intravenous drug user. The HIV epi­demic in women and children has occurred as a consequence of the under­lying epidemic of drug use among both men and women. To stop the transmission of HIV infection to black women and infants, drug use and related social issues must be addressed.

Each newborn blood specimen testing positive for HIV antibody sig­nifies both a woman infected with HIV and an infant at risk of infection. Serological diagnosis of HIV infection in neonates is problematic, due to persistence of maternal antibodies during the first months of life. Several prospective studies have estimated the perinatal transmission rate for HIV infection to be between 25% and 35%, probably close to 30%. This factor is critical to our estimate of the number of perinatally infected infants; applying it to the estimated annual number of births to HIV- infected women yields an estimate of the true incidence of perinatally acquired HIV infection. Our findings suggest that approximately 1800 infants were infected perinatally in I year, exceeding the total of 1628 children with perinatally acquired AIDS reported to the CDC from 1981 through 1989. Combined with information on the natural history of HIV infection in infants, these data can be used to evaluate completeness of AIDS case reporting and referral for clinical care.

The survey in childbearing women has the exceptional capacity, near­ly unique among large-scale serosurveys, to provide relatively unbiased estimates of HIV seroprevalence in a well-defined population, i. e. the population of women giving birth in a defined geographic area within a defined time period. Using a sample corresponding to consecutive births during a period of less than 12 months to estimate annual seroprevalence rates requires the assumptions that prevalence of HIV infection in child- bearing women does not vary seasonally and is not increasing rapidly. Although survey periods varied among participating states, no indication of a seasonal pattern emerged. Preliminary data from states where sur­veys in childbearing women have been in progress for at least 2 years sug­gest that seroprevalence has remained essentially unchanged in their respective population. Additional data are needed to assess long-term trends, especially where HIV prevalence is low.

Text 1: Chicken-pox.

Text 2: Diphtheria.

study of tumors study of kidney study of urinary system study of glands of internal secretion

5. study of the female

6. study of blood

7. study of the eye

8. study of heart

9. study of the skin

10. study of nerves

11. study of stomach and intestines

1. 2.

Grammar: Infinitive Constructions.

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