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Biomedical subjects

W Cates

Publications and source records attributed to W Cates.

At least 37 records · Page 2Linked to original sources
PubMed1997

The natural history of syphilis. Implications for the transmission dynamics and control of infection.

BACKGROUND: Syphilis remains a significant cause of morbidity in many developing countries and in some areas within North America and Europe. Mathematical models of the transmission dynamics of sexually transmitted infections have provided insights of relevance both to the interpretation of observed epidemiological patterns and to the design of control programs. Their use for the study of syphilis has been limited to date. GOALS AND STUDY DESIGN: The authors investigated the transmission dynamics of syphilis against a template based on the natural history of infection in individual patients with the aim of (1) identifying gaps in our understanding of the biology of infection, and (2) providing insights of relevance to the design of control policies. RESULTS: Analyses reveal that Treponema pallidum has a moderate to high probability of transmission during contact between susceptible and infectious sexual partners. This, combined with questions over the existence of any immunity to reinfection, helps to ensure the long-term persistence of syphilis within "core" activity groups. Patterns of treatment in North America are shown to have significantly altered the relative frequency of individuals in the different stages of disease. CONCLUSIONS: The analyses emphasize the benefits to be gained from treating infected people early in the primary stage of infection to reduce the effective period during which infected people can transmit to others. This form of treatment is beneficial for both the individual and the community. Treatment has greatly altered the incidence of different disease stages, but the full implications of treatment depend on whether immunity is present.

Contact Tracing↗
PubMed1997

Primary HIV infection--a public health opportunity.

Primary human immunodeficiency virus (HIV) infection should be considered a key target for HIV prevention activities. Mathematical models suggest that the primary HIV infection interval makes a disproportionate contribution to the HIV epidemic, perhaps accounting for as many as half of the existing infections at any point in time. If this is true, primary infection presents a special window of opportunity within which to exert a maximum impact on the spread of HIV. A combination of biological, behavioral, and social factors may account for the influence of primary infection on the HIV epidemic. HIV prevention measures can be focused on each of these factors. Biologically, detecting individuals early in the course of infection and offering treatment can reduce viral load and possibly an individual's infectiousness. Behaviorally, counseling newly infected persons about the importance of adopting safer practices may instill prevention behaviors at a critical time. Socially, using a network approach to notify persons exposed to those with primary infections can dampen the amplification effect of rapid HIV spread through high-risk environments. By focusing prevention efforts on the primary HIV infection interval, public health officials could increase their leverage in slowing the HIV epidemic.

Acute Disease↗
PubMed1995

The effectiveness of barrier methods of contraception in preventing the spread of HIV.

Because barrier methods provide protection against bacterial sexually transmitted diseases, these methods are valuable public health adjuncts irrespective of their effect on HIV. Male latex condoms offer substantial protection against HIV infection. Women at risk of sexual acquisition of HIV infection need one or more prophylactic methods that they can control. While the available spermicide products may serve this purpose, current data do not allow firm casual inferences. Large and well designed epidemiologic studies are required to examine the association between female use of barrier methods and HIV infection. These are difficult and costly to perform, however, and to date have yielded conflicting results. Finally, prospective studies in high-incidence cohorts are necessary, and the relationships between spermicide use, local irritation, the vaginal flora and HIV incidence rates must be clarified.

Condoms↗
PubMed1993

Atypical pelvic inflammatory disease: can we identify clinical predictors?

OBJECTIVE: We used data from a large multicenter case-control study of tubal infertility to analyze further the relationship among demographic variables, behavioral measures, history of previous sexually transmitted diseases, and past contraceptive practices, for women with and without a history of pelvic inflammatory disease. STUDY DESIGN: We identified 283 white women with tubal infertility who requested care at seven participating institutions. Of these women, 238 (84%) did not have a history of pelvic inflammatory disease ("atypical pelvic inflammatory disease") whereas 45 reported a history of pelvic inflammatory disease ("overt pelvic inflammatory disease"). We compared these groups with 1629 white women without a history of either infertility or pelvic inflammatory disease who were delivered of their first live-born child at the same institutions as the infertile cases. RESULTS: Women with atypical pelvic inflammatory disease were demographically more like fertile control subjects and had behavioral characteristics midway between those of the overt pelvic inflammatory disease group and the fertile group. Both oral contraceptive and diaphragm use protected against tubal infertility for women with either atypical or overt pelvic inflammatory disease. Atypical pelvic inflammatory disease was related to a history of Trichomonas infection but not to a reported history of gonorrhea, genital herpes, or other vaginitis. CONCLUSION: Atypical pelvic inflammatory disease is probably more common than its symptomatic counterpart. Whereas this condition is associated with some characteristics of a sexually transmitted infection, clinical predictors remain elusive.

Adult↗
PubMed1993

Delayed care of pelvic inflammatory disease as a risk factor for impaired fertility.

OBJECTIVE: We evaluated the relationship between delayed care of symptomatic pelvic inflammatory disease and impaired fertility. STUDY DESIGN: We used data from a cohort of women with clinically recognized pelvic inflammatory disease. Case patients were women with either ectopic pregnancy or infertility (n = 76); controls were women with intrauterine pregnancies (n = 367). RESULTS: Women who delayed seeking care for pelvic inflammatory disease were three times more likely to experience infertility or ectopic pregnancy than women who sought care promptly after adjustment for age, organism, year of diagnosis, and history of recent gynecologic events (95% confidence interval = 1.27, 6.11). This association was strongest for women with chlamydia; 17.8% (18/101) of those who delayed seeking care had impaired fertility, whereas 0.0% (0/13) of those who sought care promptly suffered known sequelae. CONCLUSIONS: Women with pelvic inflammatory disease who delay seeking care are at increased risk for infertility and ectopic pregnancy. Furthermore, our data suggest that prompt evaluation and treatment of chlamydial pelvic inflammatory disease can prevent these sequelae.

Adolescent↗
PubMed1992

Commentary: the quest for women's prophylactic methods--hopes vs science.

The companion article by Rosenberg and Gollub in this issue summarizes data from 10 observational studies and concludes that female-controlled contraceptive methods, under typical conditions, are comparable to condoms in preventing sexually transmitted diseases and should be merchandized as such. While we agree that chemical and mechanical contraceptives provide protection against some sexually transmitted diseases, we think the authors have overstated the scientific case for these methods, especially in comparison with the condom. We think the current data remain inconclusive regarding the absolute protection of spermicides against the human immunodeficiency virus and their level of protection--relative to that of the condom--against other sexually transmitted diseases. Three reasons account for our differences: the limitations in the comparative data; the reported adverse effects of spermicides on vaginal conditions, including genital ulcers; and the relative value of condoms, even under typical conditions, in preventing sexually transmitted diseases. For these reasons, we would currently counsel both women and men who practice high-risk sexual behaviors to use condoms as their first line of defense. If this is unacceptable, the female barriers become a fallback position to protect against bacterial sexually transmitted diseases.

Condoms↗
PubMed1992

Vaginal douching among women of reproductive age in the United States: 1988.

BACKGROUND: Vaginal douching has been associated with pelvic inflammatory disease (PID) in several epidemiologic studies. METHODS: To determine the extent to which douching is practiced and to describe the population subgroups in which it is most prevalent, we analyzed data from the 1988 National Survey of Family Growth, which is based on a nationally representative sample of 8450 United States women between the ages of 15 and 44 years. RESULTS: Thirty-seven percent of the sample reported douching; 18% douched at least once a week. The variable most strongly and consistently associated with douching was race: two thirds of Black women, but only one third of White women, reported douching. The practice was least frequent among 15- to 19-year-olds (31%) and most frequent among 20- to 24-year-olds (41%). Douching was more common among women who lived in poverty (50%) than among those who did not (28%). Seventy percent of Black women living in poverty reported douching. Women with less than a high school education were almost four times more likely to report douching as those with 16 or more years of schooling (56% vs 16%). Women with only 1 partner and those with 10 or more partners were less likely to douche than others. Sixteen percent of women who reported douching, compared with 10% of those who did not, also reported a history of PID. CONCLUSIONS: Douching may be a modifiable risk factor for PID, it should be a high priority for future etiologic research.

Adolescent↗