A national survey of pediatrician knowledge and attitudes regarding human papillomavirus vaccination

OBJECTIVE

A human papillomavirus vaccine was licensed in June 2006. The vaccine is quadrivalent, protecting against 2 human papillomavirus strains that cause cervical cancer and 2 that cause genital warts. The objective of this study was to determine physician characteristics, knowledge, and attitudes associated with an intention to recommend human papillomavirus vaccination.

METHODS

Between August and October 2005, a cross-sectional survey was administered to a national network of 431 pediatricians. The network was developed from a random sample of American Academy of Pediatrics members and was designed to be representative of the organization's membership with respect to urban/rural location, practice type, and region. The survey was conducted before human papillomavirus vaccine licensure and therefore focused on a candidate quadrivalent human papillomavirus vaccine and a range of potential vaccination recommendations. The main outcome measure was intention to recommend a quadrivalent human papillomavirus vaccine to young adolescent (10- to 12-year-old) females.

RESULTS

Survey response rate was 68%. If endorsed by national health organizations, 46% of respondents would recommend vaccination for 10- to 12-year-old females, 77% for 13- to 15-year-old females, and 89% for 16- to 18-year-old females. Corresponding rates for males were 37%, 67%, and 82%, respectively. Whereas 60% of respondents thought that parents would be concerned that human papillomavirus vaccination may encourage risky sexual behaviors, 11% reported that they themselves had this concern. Respondents who believed that other new adolescent immunization recommendations (eg, meningococcal, pertussis) would facilitate human papillomavirus vaccine implementation were more likely to intend to recommend vaccination.

CONCLUSIONS

Although a national sample of pediatricians expressed a high level of acceptance of human papillomavirus vaccination in older adolescent females, fewer than one half anticipated giving human papillomavirus vaccine to younger female patients. Provider concerns about parental vaccine acceptance will need to be addressed to optimize human papillomavirus vaccination implementation.

Prevalence of HPV infection among men: A systematic review of the literature

BACKGROUND

Human papillomavirus (HPV) infection is estimated to be the most common sexually transmitted infection; an estimated 6.2 million persons are newly infected every year in the United States. There are limited data on HPV infection in heterosexual men.

METHODS

We conducted a systematic review of the literature by searching MEDLINE using the terms "human papillomavirus," "HPV," "male," "seroprevalence," and "serology" to retrieve articles published from 1 January 1990 to 1 February 2006. We included studies that had data on population characteristics and that evaluated male genital anatomic sites or specimens for HPV DNA or included assessments of seropositivity to HPV type 6, 11, 16, or 18 in men. We excluded studies that had been conducted only in children or immunocompromised persons (HIV infected, transplant recipients, or elderly).

RESULTS

We included a total of 40 publications on HPV DNA detection and risk factors for HPV in men; 27 evaluated multiple anatomic sites or specimens, 10 evaluated a single site or specimen, and 3 evaluated risk factors or optimal anatomic sites/specimens for HPV detection. Twelve studies assessed site- or specimen-specific HPV DNA detection. HPV prevalence in men was 1.3%-72.9% in studies in which multiple anatomic sites or specimens were evaluated; 15 (56%) of these studies reported > or =20% HPV prevalence. HPV prevalence varied on the basis of sampling, processing methods, and the anatomic site(s) or specimen(s) sampled. We included 15 publications reporting HPV seroprevalence. Rates of seropositivity depended on the population, HPV type, and methods used. In 9 studies that evaluated both men and women, all but 1 demonstrated that HPV seroprevalence was lower in men than in women.

CONCLUSION

HPV infection is highly prevalent in sexually active men and can be detected by use of a variety of specimens and methods. There have been few natural-history studies and no transmission studies of HPV in men. The information that we have reviewed may be useful for future natural-history studies and for modeling the potential impact of a prophylactic HPV vaccine.

Trends in herpes simplex virus type 1 and type 2 seroprevalence in the United States

CONTEXT

Herpes simplex virus type 1 (HSV-1) and type 2 are common infections worldwide. Herpes simplex virus type 2 (HSV-2) is the cause of most genital herpes and is almost always sexually transmitted. In contrast, HSV-1 is usually transmitted during childhood via nonsexual contacts. Preexisting HSV-1 antibodies can alleviate clinical manifestations of subsequently acquired HSV-2. Furthermore, HSV-1 has become an important cause of genital herpes in some developed countries.

OBJECTIVE

To examine trends in HSV-1 and HSV-2 seroprevalence in the United States in 1999-2004 compared with 1988-1994.

DESIGN, SETTINGS, AND PARTICIPANTS

Cross-sectional, nationally representative surveys (US National Health and Nutrition Examination Surveys [NHANES]), were used to compare national seroprevalence estimates from 1999-2004 with those from 1988-1994, and changes in HSV-1 and HSV-2 seroprevalence since 1976-1980 were reviewed. Persons aged 14 to 49 years were included in these analyses.

MAIN OUTCOME MEASURES

Seroprevalence of HSV-1 and HSV-2 antibodies based on results from type-specific immunodot assays; diagnosis of genital herpes.

RESULTS

The overall age-adjusted HSV-2 seroprevalence was 17.0% (95% confidence interval [CI], 15.8%-18.3%) in 1999-2004 and 21.0% (95% CI, 19.1%-23.1%) in 1988-1994, a relative decrease of 19.0% between the 2 surveys (95% CI, -28.6% to -9.5%; P<.001). Decreases in HSV-2 seroprevalence were especially concentrated in persons aged 14 to 19 years between 1988 and 2004. In adolescents aged 17 to 19 years and young adults, the decreases in HSV-2 seroprevalence were significant even after adjusting for changes in sexual behaviors. Among those infected with HSV-2, the percentage who reported having been diagnosed with genital herpes was statistically different (14.3% in 1999-2004 and 9.9% in 1988-1994; P = .02). Seroprevalence of HSV-1 decreased from 62.0% (95% CI, 59.6%-64.6%) in 1988-1994 to 57.7% (95% CI, 55.9%-59.5%) in 1999-2004, a relative decrease of 6.9% between the 2 surveys (95% CI, -11.6% to -2.3%; P = .006). Among persons infected with HSV-1 but not with HSV-2, a higher percentage reported having been diagnosed with genital herpes in 1999-2004 compared with 1988-1994 (1.8% vs 0.4%, respectively; P<.001).

CONCLUSIONS

These data show declines in HSV-2 seroprevalence, suggesting that the trajectory of increasing HSV-2 seroprevalence in the United States has been reversed. Seroprevalence of HSV-1 decreased but the incidence of genital herpes caused by HSV-1 may be increasing.

Genital human papillomavirus infection

Over the past few decades, epidemiology and natural history studies have led to improved understanding of human papillomavirus (HPV) infection and to promising prevention strategies. HPV infection is the cause of anogenital warts and cervical cancer, as well as a proportion of other anogenital and head and neck cancers. Data from clinical trials have resulted in recommendations that support the use of an HPV test in the context of cervical cancer screening and management. Prophylactic HPV vaccine trials have demonstrated high efficacy, and an HPV vaccine that prevents cervical cancer precursors, cervical cancer, and anogenital warts caused by HPV types 6, 11, 16, and 18 was licensed for use in girls and women aged 9-26 years by the US Food and Drug Administration (FDA) in June 2006. In this article, we review genital HPV for the clinician, with a primary focus on the prevalence of HPV infection in the United States.

Effect of specimen order on Chlamydia trachomatis and Neisseria gonorrhoeae test performance and adequacy of Papanicolaou smear

STUDY OBJECTIVE

To evaluate the effect of specimen collection order on the performance of diagnostic tests for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC), and the specimen adequacy of ThinPrep Papanicolaou (Pap) smears.

DESIGN

Prospective cohort study.

SETTING

Public adolescent clinic.

POPULATION

313 women.

INTERVENTIONS

The order of five cervical testing specimens was randomized for (1) ligase chain reaction (LCR) and (2) polymerase chain reaction (PCR) for both CT and GC; (3) transcription-mediated amplification (TMA) for CT; (4) culture for CT; and (5) cytology and LCR for GC and CT performed on ThinPrep Pap specimens. For CT and GC, a reference standard was based on three different tests performed on separate specimens. Generalized estimating equations were used to account for repeated measures.

MAIN OUTCOME MEASURE

Sensitivity and specificity of diagnostic tests.

RESULTS

The proportion of inadequate Pap smears was independent of specimen order. As a group, nucleic acid amplification test (NAAT) sensitivity and specificity for GC and CT were similar in the first two (early) and last three (late) swabs. Although point estimates for sensitivity were higher in the early swabs compared to the late swabs for GC LCR (13% difference), GC PCR (13%), and CT TMA (10%), these differences were not statistically significant. Their clinical significance warrants further investigation.

CONCLUSIONS

In clinical settings where both Pap smears and STI testing are performed in adolescents, clinical considerations can influence the order of specimen collection, since neither Pap specimen adequacy nor test performance of NAAT for CT and GC were significantly associated with swab order.

Trends in Pelvic Inflammatory Disease Hospital Discharges and Ambulatory Visits, United States, 1985–2001

OBJECTIVE

The objective of this study was to describe the estimated trends in incidence of pelvic inflammatory disease (PID) among reproductive-aged women in hospital and ambulatory settings.

STUDY

Analyses of PID estimates were performed. Three nationally representative surveys conducted by the National Center for Health Statistics (NCHS): National Hospital Discharge Survey (NHDS), National Hospital Ambulatory Medical Care Survey (NHAMCS), and National Ambulatory Medical Care Survey (NAMCS), were used to obtain the estimates of PID (defined by International Classification of Diseases, 9th Revision codes). National Disease and Therapeutic Index (NDTI) estimates were reviewed for comparison.

RESULTS

Rates of hospitalized PID declined 68% overall from 1985 through 2001 (P <0.0001). Ambulatory data support a decrease in PID from 1985 to 2001. From 1995 to 2001, approximately 769,859 cases of acute and unspecified PID were diagnosed annually, 91% in ambulatory settings.

CONCLUSIONS

PID has decreased in hospital and ambulatory settings. The expanded national surveys in outpatient and emergency departments provide more complete estimates for PID. Optimal management of PID should target ambulatory settings, where the majority of cases are diagnosed and treated.

Cervical specimen order and performance measures of Chlamydia trachomatis diagnostic testing

The orders of three endocervical specimens of 3,561 women for Chlamydia trachomatis testing were randomized to determine whether test performance measures of two nucleic acid amplification tests and a DNA probe were affected by swab order. Specimen collection order did not appear to affect the diagnostic accuracy of these tests.

Association of Chlamydia trachomatis with persistence of high-risk types of human papillomavirus in a cohort of female adolescents

Human papillomavirus (HPV) infection is a necessary but not sufficient cause of cervical cancer. While chlamydia infection has been associated with cervical cancer, the meaning of this association remains unclear. The authors' objective was to investigate this association by evaluating whether concurrent genital tract infections are associated with HPV persistence, a precursor to cervical cancer. Interview data and biologic samples for HPV, Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and bacterial vaginosis testing were collected from female adolescents in an Atlanta, Georgia, longitudinal cohort study at 6-month visits (1999-2003). Associations with persistence (detection of the same HPV type at two sequential visits (visit pair)) were assessed among subjects with 2-5 visits and > or =6 months of follow-up. Associations were evaluated by logistic regression using methods for correlated data. Type-specific persistence of high-risk HPV types was detected in 77 of 181 (43%) analyzed visit pairs. Concurrent infection with C. trachomatis was independently associated with persistence of high-risk HPV types (adjusted odds ratio = 2.1, 95% confidence interval: 1.0, 4.1). Infection with more than one HPV type at the initial visit was also associated with high-risk persistence (adjusted odds ratio = 2.8, 95% confidence interval: 1.6, 4.9). The association between chlamydia infection and cervical cancer may be due to an effect of chlamydia infection on persistence of high-risk HPV.

The natural history of HIV-1 infection in young Thai men after seroconversion

The natural history and progression of HIV-1 infection in Thailand and other developing countries in Asia and Africa have not been well defined. Nevertheless, valid data are needed to evaluate the effects of interventions, which are designed to delay progression. We evaluated the progression to AIDS and death in 235 men who seroconverted during their 2 years of service in the Royal Thai Army. The men were conscripted at age 21 and seroconverted within a 6-month window during follow-up while in the military. The seroconverters were matched with men who were seronegative when discharged. Of the HIV-positive men, 156 (66.4%) were alive, 77 (32.8%) had died, and 2 (0.8%) could not be located 5-7 years after their seroconversion and discharge from the military. The 5-year survival rate was 82.3%; the median times to clinical AIDS and a CD4 cell count of <200/microL was 7.4 years and 6.9 years, respectively. The mortality rate was 56.3 deaths per 1000 patient-years for HIV-positive men and 6.1 deaths per 1000 patient-years for HIV-negative men. Our data suggest a more rapid progression to AIDS and death after HIV-1 infection in young men in Thailand than has been reported for similarly aged cohorts in developed countries.

The Effect of Correct and Consistent Condom Use on Chlamydial and Gonococcal Infection Among Urban Adolescents

OBJECTIVE

To evaluate the relationship between self-reported correct and consistent condom use and chlamydial and gonococcal infection.

DESIGN

Cross-sectional study.

SETTING

An urban adolescent health care clinic. Patients A total of 509 adolescent girls tested for Chlamydia trachomatis and Neisseria gonorrhoeae infection by urine nucleic acid amplification tests. Main Outcome Measure Effect of condom use on infection rates of chlamydia and gonorrhea. Consistent condom use was defined as using condoms for every act of vaginal sex and correct use as consistent use without any of the following: beginning sex without a condom, taking it off before finishing sex, flipping it over, condom breakage, or condom slippage.

RESULTS

A total of 95% of the participants were African American, with a mean age of 16.6 years. Chlamydia prevalence was 21% (105/509) and gonorrhea prevalence was 7% (36/509). Condom errors were reported by 316 (71%) of 442 participants who had reported using a condom at least once in the previous 3 months. Consistent use was reported by 176 patients (35%); however, both correct and consistent use was reported by only 80 patients (16%). After adjusting for confounders, correct and consistent use was protective for chlamydia (odds ratio, 0.4; 95% confidence interval, 0.2-1.0) and highly protective for gonorrhea (odds ratio, 0.1; 95% confidence interval, 0-0.7).

CONCLUSION

Our findings indicate that assessing both correctness and consistency of use is important for evaluation of condom effectiveness.

Seroprevalence of Human Papillomavirus Type 16 in Children

We evaluated the prevalence of antibodies to human papillomavirus (HPV) type 16 in a representative sample of children 6-11 years of age in the United States. Serum samples and questionnaire data were collected between 1991 and 1994, for the National Health and Nutrition Examination Survey III. HPV-16-specific immunoglobulin G antibodies were detected by an HPV-16 L1 virus-like particle-based enzyme-linked immunosorbant assay. Overall, 2.4% of 1316 children 6-11 years of age were seropositive. Seroprevalence was higher in boys than in girls (3.5% vs. 1.2%; P=.08) and in children >7 years of age than in children < or =7 years of age (3.3% vs. 0.4%; P<.05). None of the variables tested for, including race/ethnicity, socioeconomic status, and urban or rural residence, were significantly associated with HPV-16 seropositivity. To explain HPV-16 seropositivity in this population, further study is required.

Sexually transmitted disease services at US colleges and universities

The authors' objectives in this study were to describe the proportion of schools providing and the percentage of students with access to HIV and sexually transmitted disease (STD) education, treatment, and prevention services at 2-year and 4-year US colleges and universities. The authors mailed self-administered questionnaires to a stratified random sample (n = 910) of the 2,755 US schools with an enrollment of more than 500 students; 736 (81%) returned the survey. Four hundred seventy-four schools (60%) had a health center, representing 73% of students. Schools with a health center or housing for students were more likely to provide STD education; 52% of the schools made condoms available to students. Sixty percent of schools with health centers could test for both Chlamydia trachomatis and Neisseria gonorrhoeae, but only 67% of these schools screened women for these infections. Although most schools provided some prevention education, access to prevention, testing, and education should be increased at schools where these services are possible but not available.

Comparison of vaccination with measles-mumps-rubella vaccine at 9, 12, and 15 months of age

To determine seroconversion rates with measles-mumps-rubella vaccine administered to children at 9, 12, or 15 months of age, we undertook a prospective randomized trial. Among children vaccinated at 15 months of age, 98% seroconverted to measles, compared with 95% of those vaccinated at 12 months of age and 87% of those vaccinated at 9 months of age. In each age group, children of mothers born in or before 1963 had lower rates of seroconversion against measles, with the lowest rate in children vaccinated at 9 months. The seroconversion rate of rubella paralleled that of measles, with the lowest seroconversion rates in children vaccinated at 9 months of age whose mothers were born in or before 1963. The response to mumps varied little by age of the child or birth year of the child's mother. These results support the recommended age for first vaccination with measles-mumps-rubella at 12-15 months.

Developments in the screening for Chlamydia trachomatis: a review

Many studies have evaluated selective screening criteria for women in various settings. Most have concluded and all guidelines recommend that all women aged < 25 be screened yearly for C. trachomatis infection. Behavioral criteria, such as the number of sex partners, new or more than one sex partners, and previous infection, also can serve as criteria for screening women aged > 25. Because re-infection rates are high and occur within a few months, complications may be reduced further if partners are treated and women rescreened 4 to 6 months after initial infection. Revised recommendations for C. trachomatis screening programs have stated that more frequent screening may be considered among women < 20 and those with recent infection. Screening in nontraditional settings and careful evaluation of local prevalence and risk factor information should be encouraged. Private providers and emergency room providers should discuss screening recommendations and adopt a C. trachomatis screening policy for the population they serve. The HEDIS measure should serve to encourage at least annual screening of 15- to 25-year-old sexually active females through providers linked to managed care organizations. In general, high yields (ie, percentage of tests that are positive) in nontraditional settings and enhanced feasibility and acceptability of urine-based tests may encourage further innovative approaches to reach and screen populations at risk. Several issues remain to be addressed to increase the effectiveness of screening efforts. If more sensitive amplification tests are used widely, more infected persons will be identified and treated, and transmission patterns may change, particularly if partner treatment also occurs. Current screening criteria should continue to be re-evaluated. An important issue that affects testing methods includes the possible need for confirmation testing when using NAATs if the prevalence of C. trachomatis is less than 2%. If the sensitivity of an NAAT is 85% and specificity is 99%, in a hypothetical population of 10,000 with a prevalence of 2%, the positive predictive value is 170/268 (63%). A second important issue affecting testing methods and feasibility of using NAATs for screening large numbers of individuals is the pooling of urine specimens, which has been evaluated in several studies and found to be very effective for reducing costs. A research issue for pooling is the determination of the most cost-effective prevalence levels for pooling. An additional research question is in which populations should a NAAT be used for detection of C. trachomatis and N. gonorrhoeae. There are no recommendations for the routine screening of men because of the paucity of data showing that this strategy can reduce sequelae. The CDC is conducting a multisite study to examine the feasibility, acceptability, and usefulness of screening of asymptomatic men. There are a few studies have determining cost-effective prevalence threshold levels, particularly with NAATs. A recently developed decision analysis model by CDC designed to maximize the effectiveness of screening strategies for C. trachomatis infections may be useful for decision makers. It is intended to serve as an easy and flexible tool to determine cost effectiveness at a local level and takes into account positivity rates and test performance characteristics (SOCRATES). It is unclear if recurrent infection is caused by true re-infection by the same or a different partner or recurrence of initial infection. Recurrence may be caused by persistence of C. trachomatis or antibiotic resistance. This distinction is of scientific interest because the appropriate intervention differs (eg, identification of risk factors for the former and microbiologic investigations for the latter). Effective partner management and retesting are critical to reducing sequelae of C. trachomatis infection. Screening for C. trachomatis infection remains an essential component of C. trachomatis control. It is cost effective, most infections are asymptomatic, and symptom-based health care seeking and testing identify few of those infected. The likelihood that opportunities for screening are missed is high particularly in non-STD clinic settings. Local studies using NAATs to determine C. trachomatis prevalence and risk factors are helpful to health care providers so they can make evidence-based decisions on who to screen. The use of nontraditional, non-clinic-based test settings should be explored further. We have focused on summarizing the medical evidence regarding recommendations for screening for C. trachomatis. High-risk populations for C. trachomatis infection may overlap with populations for other STDs, and comprehensive STD prevention programs that involve a range of STD service providers are needed to successfully reduce the STD-related health burden in the population.

The Emergence of Neisseria gonorrhoeae With Decreased Susceptibility to Azithromycin in Kansas City, Missouri, 1999 to 2000

BACKGROUND AND OBJECTIVES

We describe the first cluster of persons with Neisseria gonorrhoeae with decreased susceptibility to azithromycin (AziDS; minimum inhibitory concentration >/=1.0 microg/mL) in the United States. GOAL The goal of this study was to identify risk factors for AziDS N. gonorrhoeae and to describe isolate microbiology.

STUDY DESIGN

Persons with AziDS N. gonorrhoeae (cases) were identified in Kansas City, Missouri, through the Gonococcal Isolate Surveillance Project (GISP) in 1999 and expanded surveillance, January 2000 to June 2001. A case-control study using 1999 GISP participants was conducted; control subjects had azithromycin-susceptible N. gonorrhoeae.

RESULTS

Thirty-three persons with AziDS N. gonorrhoeae were identified. Case patients were older than control patients (median age, 33 years vs. 23 years; P <0.001). Fifty percent of cases and 13% of control subjects had a history of sex with a female commercial sex worker (odds ratio, 7.0; 95% confidence interval, 1.3-36.0); 50% of cases and 4% of control subjects met sex partners on street A (P <0.01). AziDS N. gonorrhoeae isolates were phenotypically and genotypically similar and contained an mtrR gene mutation.

CONCLUSIONS

With few treatment options remaining, surveillance for antimicrobial-resistant N. gonorrhoeae is increasingly important, especially among persons at high risk.

Evaluation of the Determine Rapid Syphilis TP assay using sera

The Abbott Determine Rapid Syphilis TP assay is a treponemal test that can be used in resource-poor settings that lack laboratory facilities. However, this test has not been extensively evaluated. We measured its sensitivity and specificity by using stored serum specimens (n = 567) from all persons who tested Treponema pallidum hemagglutination assay (TPHA) positive (n = 250) or TPHA indeterminate (n = 17) in the year 2001 and the first 300 patients in 2001 who tested TPHA negative at the Evandro Chagas Research Institute in Rio de Janeiro, Brazil. This rapid assay was independently interpreted by three different observers. With TPHA results as the reference, sensitivity ranged between readers from 95.6 to 98.4% and specificity ranged from 97.3 to 95.7%. There was little interreader variability in the interpretation of results, with approximately 98% agreement for all reader combinations. Of samples from persons with human immunodeficiency virus (HIV) infection (n = 198), sensitivity was 96.9 to 99.2% and it was 94.4 to 96.3% among HIV-negative persons (n = 127). Specificity was 92.4 to 95.5% among HIV-positive persons and 97.2 to 100% among HIV-negative persons. We found this test to have high sensitivity and specificity and little interreader variability, indicating that it may be easily used in resource-poor settings without laboratory facilities. Further studies are needed using this test on whole blood and under the clinical conditions for which it is intended.

Syphilis Outbreak Among Hispanic Immigrants in Decatur, Alabama

BACKGROUND

Despite national progress in syphilis control, increases in rates have recently occurred, and syphilis is still an endemic problem in the southern United States. An outbreak of infectious syphilis among Hispanics was identified in Decatur, Alabama.

GOAL

An investigation was initiated to describe the outbreak and to assist with prevention activities.

STUDY DESIGN

We reviewed case interview records and syphilis surveillance data. The Morgan County Health Department (MCHD) performed voluntary door-to-door syphilis screening in neighborhoods where a large number of cases had been identified. During screening activities, sociodemographic and behavioral data were collected.

RESULTS

From June 2000 to February 2001, 49 cases of syphilis were reported; 26 (53%) were primary or secondary, 17 (35%) were early latent, and 6 (12%) late latent. Of the early syphilis cases, 70% were male and half were Hispanic; 93% of cases were linked to commercial sex and 70% of female cases reported crack cocaine use. During the screening, 172 individuals completed a questionnaire; 70% of participants were male, 83% were Hispanic, 17% of Hispanic participants spoke English, 21% reported sex with a commercial sex worker, and 8 (5%) had positive syphilis serology. Among men, factors associated with commercial sex were not having a regular partner (odds ratio [OR], 3.9; confidence interval [CI], 1.1-14.3), not living with a family member in the United States (OR, 4.5; CI, 1.6-12.8), and having visited their country of origin since arrival to the United States (OR, 9.2; CI, 2.3-36.5).

CONCLUSIONS

Factors contributing to this outbreak were crack cocaine use and increased prostitution in close proximity to the Hispanic community. At present, there are an increasing number of Hispanic immigrants in the United States, the majority of whom do not speak English. To prevent similar outbreaks in the future, public health officials need to be aware of the health and health education needs of these populations.

Evaluation of syphilis reactor grids: optimizing impact

BACKGROUND

A syphilis reactor grid (SRG) is an administrative tool based on the sex, age, and serologic titer of persons with reactive serologic tests for syphilis (reactors) that is used by Sexually Transmitted Disease program staff to prioritize follow-up investigations of persons who may have syphilis. The National Plan to Eliminate Syphilis from the United States recommends that state and local health departments regularly evaluate the effectiveness of their SRGs. However, there are limited methods for SRG evaluation that are feasible for sexually transmitted disease programs.

GOAL

To evaluate the sensitivity and predictive value of five currently used SRGs.

STUDY DESIGN

Comparative evaluation of five SRGs in four different populations.

RESULTS

The percentage of true syphilis cases not assigned to an investigation by an SRG (missed cases) was dependent on syphilis prevalence among reactors and on the SRG. The percentage of reactors assigned to an investigation by an SRG that were not true cases was primarily dependent on syphilis prevalence among reactors, not SRG design. Cases missed by SRGs were predominantly men aged 30 to 50 years and women aged 20 to 40 years who had low or intermediate serologic titers.

CONCLUSION

Monitoring the prevalence of syphilis among reactors is critical because in areas with high prevalence, most SRGs miss a substantial number of cases, and in areas with low prevalence, some SRGs can reduce unnecessary investigations.

The syphilis reactor grid: help or hindrance for syphilis surveillance?

BACKGROUND

Health departments use reactor grids (sex, age, and serologic test for syphilis [STS] titer criteria) to determine which persons to evaluate for untreated syphilis.

GOAL

The goal of the study was to assess reactor grid performance in Chicago and reactor grid use nationally in 1999 to 2000.

STUDY DESIGN

We reviewed Chicago health department records to identify characteristics of persons with a reactive STS excluded from evaluation by reactor grid criteria and syphilis cases not meeting evaluation criteria. We surveyed health departments regarding reactor grid use.

RESULTS

Of persons with a reactive STS, 46% did not meet criteria for health department evaluation, including 62% of men, 29% of women, and 21% with titers > or =1:8. The reactor grid would have excluded 17% of primary syphilis cases. Overall, 82% of health departments use reactor grids.

CONCLUSIONS

Reactor grids are widely used and may exclude persons with infectious syphilis from health department evaluation, especially men. The impact of reactor grid use on syphilis control and surveillance in the United States should be evaluated.

Comparison of methods for detection of Chlamydia trachomatis and Neisseria gonorrhoeae using commercially available nucleic acid amplification tests and a liquid pap smear medium

Annual screening for Chlamydia trachomatis infection is currently recommended for sexually active women 15 to 25 years old and for women older than 25 if they have a new or multiple sex partners and have not used condoms during the previous 3 months. Annual screening for cervical abnormalities using the Pap smear has achieved a substantial reduction in morbidity and mortality from cervical cancer. Screening for Neisseria gonorrhoeae infection has likely contributed significantly to the reduction in the rates of gonococcal infection. The introduction of liquid Pap smear methods using exfoliated cervical cells presents an opportunity to screen for these three conditions using one specimen. We evaluated the preservation of C. trachomatis and Neisseria gonorrhoeae DNAs from ThinPrep liquid media (PreservCyt; Cytyc Corp., Boxborough, Mass.); tested the feasibility of using a clinical specimen of this medium for the detection of cytologic abnormalities, C. trachomatis, and N. gonorrhoeae; evaluated the agreement between ligase chain reaction (LCR) performed on PreservCyt and LCR performed on a cervical specimen; and compared the performance of LCR performed on PreservCyt to those of LCR performed on a cervical specimen, culture, PCR performed on a cervical specimen, on urine, and on a vaginal specimen (a multiple-site infection status standard), and transcription-mediated amplification (for C. trachomatis only) from 255 sexually active adolescent women. The agreement between LCR performed on PreservCyt and LCR from a cervical swab in LCx transport medium was high (for C. trachomatis, agreement = 0.97 and kappa = 0.92; for N. gonorrhoeae, agreement = 0.99 and kappa = 0.96). Test performances were similar for LCR-urine, LCR-cervix, and LCR-ThinPrep, with sensitivities from 93 to 99% for C. trachomatis and 81 to 83% for N. gonorrhoeae and specificities from 95.5 to 99% for C. trachomatis and 99.1 to 99.6% for N. gonorrhoeae using a PCR-based multiple-site infection status standard. This is the first study to examine the agreement between liquid cytologic media and multiple nucleic acid amplification tests for the detection of C. trachomatis and N. gonorrhoeae from patient samples. Cytologic fluid shows promise for simultaneous screening for cytologic abnormalities and sexually transmitted infections.

Patient-delivered partner treatment with azithromycin to prevent repeated Chlamydia trachomatis infection among women: a randomized, controlled trial

BACKGROUND

Repeated infection with C trachomatis increases the risk for serious sequelae: pelvic inflammatory disease, ectopic pregnancy, infertility, and chronic pelvic pain. A substantial proportion of women treated for C trachomatis infection are reinfected by an untreated male sex partner in the first several months after treatment. Effective strategies to ensure partner treatment are needed.

GOAL

The goal of the study was to determine whether repeated infections with C trachomatis can be reduced by giving women doses of azithromycin to deliver to male sex partners.

STUDY DESIGN

A multicenter randomized controlled trial was conducted among 1,787 women aged 14 to 34 years with uncomplicated C trachomatis genital infection diagnosed at family planning, adolescent, sexually transmitted disease, and primary care clinics or emergency or other hospital departments in five US cities. Women treated for infection were randomized to one of two groups: patient-delivered partner treatment (in which they were given a dose of azithromycin to deliver to each sex partner) or self-referral (in which they were asked to refer their sex partners for treatment). The main outcome measure was C trachomatis DNA detected by urine ligase chain reaction (LCR) or polymerase chain reaction (PCR) by 4 months after treatment.

RESULTS

The characteristics of study participants enrolled in each arm were similar except for a small difference in the age distribution. Risk of reinfection was 20% lower among women in the patient-delivered partner treatment arm (87/728; 12%) than among those in the self-referral arm (106/726; 15%); however, this difference was not statistically significant (odds ratio, 0.80; 95% confidence interval, 0.62-1.05; = 0.102). Women in the patient-delivered partner treatment arm reported high compliance with the intervention (82%).

CONCLUSION

Patient-delivered partner treatment for prevention of repeated infection among women is comparable to self-referral and may be an appropriate option for some patients.

Screening tests to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections--2002

Since publication of CDC's 1993 guidelines (CDC, Recommendations for the prevention and management of Chlamydia trachomatis infections, 1993. MMWR 1993;42[No. RR-12]:1-39), nucleic acid amplification tests (NAATs) have been introduced as critical new tools to diagnose and treat C. trachomatis and Neisseria gonorrhoeae infections. NAATs for C. trachomatis are substantially more sensitive than previous tests. When using a NAAT, any sacrifice in performance when urine is substituted for a traditional swab specimen is limited, thus reducing dependence on invasive procedures and expanding the venues where specimens can be obtained. NAATs can also detect both C. trachomatis and N. gonorrhoeae organisms in the same specimen. However, NAATs are usually more expensive than previous tests, making test performance from an economic perspective a key consideration. This report updates the 1993 guidelines for selecting laboratory tests for C. trachomatis with an emphasis on screening men and women in the United States. (In this report, screening refers to testing persons in the absence of symptoms or signs indicating C. trachomatis or N. gonorrhoeae infection.) In addition, these guidelines consider tests from an economic perspective and expand the previous guidelines to address detection of N. gonorrhoeae as well as C. trachomatis infections. Because of the increased cost of NAATs, certain laboratories are modifying manufacturers' procedures to improve test sensitivity without incurring the full cost associated with screening with a NAAT. Such approaches addressed in these guidelines are pooling of specimens before testing with a NAAT and additional testing of specimens whose non-NAAT test result is within a gray zone. This report also addresses the need for additional testing after a positive screening test to improve the specificity of a final diagnosis. To prepare these guidelines, CDC staff identified pertinent concerns, compiled the related literature published during 1990 or later, prepared tables of evidence, and drafted recommendations. Consultants, selected for their expertise or disciplinary and organizational affiliations, reviewed the draft recommendations. These final guidelines are the recommendations of CDC staff who considered contributions from scientific consultants. These guidelines are intended for laboratorians, clinicians, and managers who must choose among the multiple available tests, establish standard operating procedures for collecting and processing specimens, interpret test results for laboratory reporting, and counsel and treat patients.

Indications for therapy and treatment recommendations for bacterial vaginosis in nonpregnant and pregnant women: a synthesis of data

Accumulating evidence has associated bacterial vaginosis (BV) with serious medical complications such as premature delivery. The present article synthesizes available data on the treatment of nonpregnant and pregnant women with BV to prevent preterm delivery. A literature search identified articles published since 1976 that evaluated treatment of BV. An intention-to-treat sensitivity analysis was performed, to better compare studies. Studies that evaluated therapy efficacy varied with regard to diagnostic criteria, patient characteristics, clinicians, and laboratories. Therapies varied in efficacy for cure 4 or more weeks after therapy, from 48% to 85%. Intervention studies to reduce BV-related adverse outcomes of pregnancy differed in populations studied, medication used, type of therapy (oral or intravaginal), and timing of treatment. The benefit of treating women at high risk with oral metronidazole has been shown in several studies; however, the effect of treating women without a history of premature delivery is unclear. The use of intravaginal clindamycin therapy, especially during the latter half of the second trimester and thereafter, appears to increase infections during the neonatal period.

Seroprevalence and coinfection with herpes simplex virus type 1 and type 2 in the United States, 1988-1994

Seroprevalence of and coinfection with herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in the United States were analyzed by use of data from a nationally representative survey (National Health and Nutrition Examination Survey III, 1988-1994). Evidence was explored for possible protection by prior HSV-1 infection against infection and clinical disease with HSV-2. Overall, 27.1% of persons aged > or =12 years were seronegative for HSV-1 and HSV-2; 51.0% were seropositive for HSV-1 only, 5.3% for HSV-2 only, and 16.6% for both HSV-1 and HSV-2. The seroprevalence of HSV-2 was higher in persons with HSV-1 antibody. Approximately 76% of persons who had HSV-2 antibody also had HSV-1 antibody. Persons seropositive for HSV-2 only reported a history of genital herpes more frequently (16.2%) than persons seropositive for both HSV-1 and HSV-2 (5.9%). The seroprevalence of HSV-1 and age at infection may influence the epidemiology of clinical genital herpes, even if prior HSV-1 infection does not prevent HSV-2 infection.

Persons with early syphilis identified through blood or plasma donation screening in the United States

The number of persons with early syphilis who donated blood between 1995 and 2000 in the United States was estimated using data collected in the National Electronic Telecommunication System for Surveillance (NETSS). To distinguish paid from volunteer donors, cases reported in 2000 were analyzed. For the 6 years, 22 primary, 81 secondary, and 413 early latent syphilis cases were identified through donation screening. In 2000, 69 cases of early syphilis were identified through donation screening in 16 states. In 6 states that reported 53 of these cases, 31 case subjects (58%) were volunteer donors and 22 (42%) were paid donors. Eighty-one percent of volunteer donors and 64% of paid donors reported no risk factors for syphilis. After adjustment for variation in NETSS use, it was estimated that, over the 6 years, approximately 1200 cases of early syphilis were detected nationally through donation screening, and 58% of the case subjects were volunteer donors.

Amplification of the DNA polymerase I gene of Treponema pallidum from whole blood of persons with syphilis

Previous reports suggest that Treponema pallidum bacteremia occurs in persons with syphilis exposure ('incubating syphilis') and in persons with primary or secondary syphilis. During a recent syphilis outbreak, whole blood samples from 32 persons with suspected syphilis or syphilis exposure were screened using polymerase chain reaction (PCR) to amplify the DNA polymerase I gene (polA) of T. pallidum. Of the 32 samples, polA was amplified from 13 (41%). Of these 13, three were determined to have incubating syphilis; two had primary or secondary syphilis and eight had latent syphilis. This study demonstrates that spirochetemia can occur throughout the course of T. pallidum infection.

Molecular subtyping of Treponema pallidum in an Arizona County with increasing syphilis morbidity: use of specimens from ulcers and blood

A molecular-based subtyping system for Treponema pallidum was used during an investigation of increasing syphilis in Maricopa County, Arizona. Genital ulcer or whole blood specimens from patients with syphilis were assayed by a polymerase chain reaction (PCR) amplification of a T. pallidum DNA polymerase I gene. Positive specimens were typed on the basis of PCR amplification of 2 variable genes. In all, 41 (93%) of 44 of ulcer specimens and 4 (27%) of 15 blood specimens yielded typeable T. pallidum DNA. Twenty-four (53%) of 45 specimens were subtype 14f; other subtypes identified included 4f, 4i, 5f, 12a, 12f, 14a, 14d, 14e, and 14i. Only 2 specimens were from epidemiologically linked patients. This investigation demonstrates that multiple subtypes of T. pallidum can be found in an area with high syphilis morbidity, although 1 subtype (14f) was predominant. Four typeable specimens were from blood, a newly identified specimen source for subtyping.

Sexually Transmitted Diseases of Older Persons in Washington State

BACKGROUND

Sexually transmitted diseases (STDs) in persons older than 50 years are rarely studied because STDs are more common in young people. Understanding the epidemiology of STDs in older persons is important for reducing STD morbidity and for improving STD care.

GOAL

To understand the epidemiology of STDs in older persons.

METHODS

Washington State's STD surveillance data from 1992 to 1998 were analyzed to describe the burden of STDs and source of care for these diseases in older persons.

RESULTS

From 1992 to 1998, 1535 episodes of STDs were reported for 50- to 80-year-olds in Washington State, accounting for 1.3% of all reported STDs. The most common STDs were nongonococcal urethritis in men and genital herpes in women. As compared with younger persons, older individuals more frequently sought care at private clinics and had symptoms at the time of the clinic visit.

CONCLUSIONS

Sexually transmitted diseases are reported among older persons, although at lower rates than among younger persons. Services for STD and counseling regarding safe sex should be available to persons of all ages.

HIV type 1 subtype E-infected patients with broadened, dual (B/E) V3 loop serology have increased cross-neutralizing antibodies

The two prevalent subtypes of HIV-1 circulating in Thailand are subtypes E and B. While the most prevalent subtype continues to be E using molecular typing assays, immunologically, a subset of subtype E-infected patients (3.4% in 1997) have binding antibodies to both the E and B V3 loops in a peptide ELISA. To assess the potential function of this dual (B/E) V3 reactivity, plasmas from patients with genetically defined HIV-1 subtype E infection and either E or B/E V3 serotypes were compared for magnitude and breadth of neutralization of seven primary and laboratory-adapted subtype B and E viruses. Dually reactive (B/E) plasmas showed significantly increased cross-neutralizing activity against subtype B viruses (p < 0.001), and increased neutralization of the panel of viruses overall (p < 0.02), as compared to monoreactive E serotype plasmas. While the total envelope binding antibody titers to both subtype B and E envelopes did not differ significantly between the E and B/E plasmas, 67% of B/E plasmas neutralized >50% of the viruses in the panel, and only 14% of E plasmas showed this broadened neutralizing activity. These data suggest that dual (B/E) V3 loop reactivity may be a marker of broader immune recognition of HIV envelope epitopes in subtype E-infected patients. V3 loop antibody, perhaps in conjunction with antibodies to additional epitopes, may play a role in neutralization of virus isolates from Thailand.

Sexually transmitted diseases during pregnancy: screening, diagnostic, and treatment practices among prenatal care providers in Georgia

BACKGROUND

Sexually transmitted diseases (STD) during pregnancy are associated with adverse outcomes. We conducted a prenatal care provider survey to determine STD screening, diagnosis, and treatment practices.

METHODS

Standard questionnaires were mailed to Georgia-licensed obstetrician/ gynecologists, family practitioners, and nurse-midwives (N = 3,082) in 1998.

RESULTS

Of the 1,300 care providers who returned the survey, 565 (44%) provided prenatal care, 390 (57%) were male, and 396 (70%) were obstetrician/ gynecologists. Overall, 553 prenatal care providers (98%) reported screening all pregnant patients for syphilis, 551 (98%) for hepatitis B, 501 (89%) for trichomonas, 474 (84%) for human immunodeficiency virus (HIV), 401 (71%) for gonorrhea, 403 (71%) for chlamydia, 475 (84%) for group B streptococci, and 130 (23%) for bacterial vaginosis (BV) (high risk). Less than 10% used amplification tests for chlamydia or gonorrhea. Most providers used appropriate regimens to treat STD in pregnant women. A written office policy on testing for BV or HIV was associated with increased screening.

CONCLUSIONS

Provider education is needed about diagnosis and treatment of STD during pregnancy.

Repeat Chlamydia trachomatis infection in women: analysis through a surveillance case registry in Washington State, 1993-1998

Repeat infections with Chlamydia trachomatis are associated with increased risk for long-term sequelae. The authors analyzed the frequency and predictors of repeat chlamydial infection by using a population-based chlamydia registry in Washington State and evaluated whether women would seek care at the same clinic for repeat infections. Among 32,698 women with an appropriately treated initial chlamydial infection during 1993-1998, 15% developed one or more repeat infections during a mean follow-up time of 3.4 years. Among women less than age 20 years at the time of initial infection, 6% were reinfected by 6 months, 11% by 1 year, and 17% by 2 years. Young age was the strongest predictor for one and two or more repeat infections after controlling for the length of follow-up and other variables. Only 36% of the repeat infections were diagnosed at the same clinical setting as the initial infection, and 50% were diagnosed at the same type of clinic. Adolescent girls had the least consistency in the source of care for chlamydia. This study suggests that efforts to prevent repeat chlamydial infection in young women remain an urgent public health priority and that the burden of repeat infection may be substantially higher than estimates from clinic-based studies.

Willingness to participate in HIV-1 vaccine trials among young Thai men

OBJECTIVES

Willingness to participate in HIV-1 vaccine trials and associated factors were investigated in a sample of 2670 Royal Thai Army conscripted recruits.

METHODS

Self administered questionnaires were used. Data were collected during the final visit of a longitudinal cohort study of HIV-1 epidemiology. Cross sectional analysis of data from this visit was performed.

RESULTS

32% of the respondents reported they would "definitely" join an HIV-1 vaccine trial. Greater willingness was associated with perceived risk of HIV-1 infection and a desire to help Thai society, although tangible incentives and intentions to reduce condom use in a vaccine trial also were associated with increased willingness. Concerns about physical harm and anticipated social pressure from family not to join were the most substantial impediments to willingness. Concerns about "social harm" (for example, participation would give appearance of having AIDS virus, a partner might refuse sex) also appeared to inhibit interest in joining trials and approached significance.

CONCLUSIONS

Willingness to participate was somewhat greater than in other investigations of non-injection drug user (IDU) cohorts in Thailand, with fewer concerns expressed about physical harm. Motivations appear to involve tradeoffs among perceived risk, anticipated social pressure, altruism, and tangible rewards. The absence of significant problems associated with vaccine trials to date, along with the presence of educational interventions in the study may help explain the lower level of concerns here relative to other Thai studies.

A comparative study of the impact of HIV infection on natural killer cell number and function in Thais and North Americans

Innate immunity may play a role in preventing HIV infection and progression to AIDS. Most studies of natural killer (NK) cell function have been conducted in populations with different HLA allele frequencies and HIV subtypes than those found in Southeast Asia. NK cell number and function, defined as CD3- cells expressing CD16+/CD56+ and the ability to lyse K562 cells, were enumerated in 42 HIV-seronegative Thais and 20 HIV-seronegative North Americans. The number and percentage of NK cells were similar for both groups, but cytotoxicity function expressed as lytic units (LU20) of NK cells was significantly greater in the Thai subjects compared with the North American subjects (p = 0.004). Comparisons were also conducted between the HIV-seronegative groups and HIV-infected subjects from both Thailand and North America. NK cell number and function were not significantly different between the Thai HIV-seronegative and -seropositive groups. However, the comparison between the North American HIV-seronegative and -seropositive subjects demonstrated profound impairment of NK cell number, percentage, and function (p < 0.001). Matching the Thai and North American HIV-infected subjects on CD4+ cell count revealed higher NK number and function in the Thai subjects (p < 0.001). The study indicates that NK function in both HIV-seronegative and -seropositive Thais is elevated relative to similar groups in North America.

Diversity of envelope glycoprotein from human immunodeficiency virus type 1 of recent seroconverters in Thailand

The envelope-coding sequence of human immunodeficiency virus type 1 (HIV-1) was determined for 11 Thai seroconverters between 1995 and 1996. On the basis of the env sequences, all subjects were infected with HIV subtype E. Compared with the interpatient protein diversity among HIV-1 Thai reference sequences from 1990 to 1992 (4.4%), the diversity among the 1995-1996 seroconverters was approximately double (9.5%). The tetrapeptide tip of the V3 loop was invariant for 10 of the 11 seroconverters, and identical to that observed in sequences derived from the 1990-1992 group. However, in the V3 region, sequences from 2 of the 11 subjects demonstrated more than 5 amino acid changes relative to the reference strains. This may represent the "aging" of the HIV epidemic seen in other endemic regions. These findings may have substantial implications for vaccine development and evaluation for both HIV antibody and cytotoxic T lymphocyte repertoire recognition.

A phase I/II trial of HIV SF2 gp120/MF59 vaccine in seronegative thais.AFRIMS-RIHES Vaccine Evaluation Group. Armed Forces Research Institute of Medical Sciences and the Research Institute for Health Sciences

Fifty-two human immunodeficiency virus type 1, seronegative Thai adults from the community were enrolled in a double-blind, placebo controlled, phase I/II trial of HIV SF2 gp120/MF59 vaccine to determine the safety and immunogenicity of this recombinant, B clade, HIV envelope protein vaccine. Twenty-six subjects were enrolled at each of two sites in Thailand, Bangkok and Chiang Mai. Twelve subjects received placebo and 40 subjects received vaccine (50 microg). Subjects were immunized according to one of two schedules, 0, 1 and 4 or 0, 1 and 6 months. The frequency of adverse reactions was not different between placebo and vaccine subjects, nor between immunization schedules. Of vaccinees, all developed high-titer binding antibody to the immunogen (rgp120), 39 developed neutralizing antibody (NA) responses against homologous virus (HIV-1(SF2)), and 22 developed NA against heterologous virus (HIV-1(MN)). No subject demonstrated intercurrent HIV infection, however screening EIA reactivity occurred in 27% of recipients. Thus, this candidate HIV vaccine was found to be safe and immunogenic in Thai adults, laying the foundation for development of a subtype E construct in this population.

Feasibility of a preventive HIV-1 vaccine cohort among persons attending sexually transmitted disease clinics in Thailand

Persons attending sexually transmitted disease clinics at three sites in Thailand were recruited to participate in a 1-year study of HIV-1 incidence. Between September 1995 and February 1996, 31% (371 of 1205) of eligible men and 24% (161 of 659) of eligible women agreed to participate. At enrollment, HIV-1 seropositivity was 3.8% among men and 2.5% among women. Follow-up of the 514 participants who were seronegative at baseline was 78% at the 12-month visit. During the study period, 53% of men reported 2 or more sexual partners, 31% reported sex with a commercial sex worker (CSW), and 33% with a casual partner. Of those visiting CSWs, 72% reported consistent condom use. Among women, 11% reported 2 or more sexual partners. Decreased HIV risk behaviors among men were observed during the study. Four incident infections occurred in men (1.4/100 person-years, 95% confidence interval [CI] = 0.4-3.6) and none among women. Based on the observed HIV-1 incidence, HIV vaccine efficacy trials in such populations would have to be larger than previously planned or more selective of high risk subgroups for recruitment.

Nationwide surveillance of HIV-1 prevalence and subtype in young Thai men

As part of routine surveillance, an HIV-1 serosurvey of 366,074 members of successive cohorts of young Thai men entering service with the Royal Thai Army (RTA) was conducted between November 1989 and November 1995. We analyzed regional and temporal trends in HIV-1 seroprevalence in young men in Thailand and determined the proportion of infections resulting from subtypes E and B in this population in 1992 and 1995. The prevalence in 1992 was compared with that in 1995 by region and demographic group. The HIV-1 subtype was determined in a random sample of HIV-1-positive specimens in 1992 and 1995 using a V3 peptide enzyme immunoassay. From a peak of 3.7% in 1993, overall seroprevalence declined to 3.0% in 1994 and further in 1995 to 2.5%. Between 1992 and 1995, the absolute decrease in seroprevalence was greatest in the upper North (from 12.5% to 5.3%), where the prevalence has been the highest. Overall, 96.9% and 95.9% of typable specimens were determined to be subtype E in 1992 and 1995, respectively. Decline in HIV-1 seroprevalence among young men in Thailand has continued, which suggests that HIV control programs in Thailand may have been successful in decreasing spread of HIV-1. Almost all HIV-1 infections resulted from subtype E.

Sexual behavior of young men in Thailand: regional differences and evidence of behavior change

An anonymous, self-administered behavioral survey was conducted in Royal Thai Army (RTA) conscripts from 19 provinces throughout Thailand in May 1996. All (to a maximum of 350) Thai men who entered the RTA in each province were selected. Data from 5474 men were included in this analysis. High-risk behaviors were reported nationwide; however, some regional differences were found. Men from the upper North were more likely to have had a commercial sex worker (CSW) as their first sexual partner (42%) than men from any other region. However, in the past year, reported sex with CSWs in the upper North (41%) was similar to or lower than those in other regions. Consistent condom use with CSWs was higher in the North than in any other region. Condom use at first sex with CSWs increased with later years at first sex in all regions. These data suggest that past higher-risk behavior among young men in the upper northern part of Thailand may have contributed to the concentration of the HIV epidemic in that region. Risk behaviors, particularly unprotected sex, appear to be decreasing nationwide.

Correlation of genetic and serologic approaches to HIV-1 subtyping in Thailand

The aim of this study was to compare the performance of differential polymerase chain reaction (PCR) typing and peptide enzyme-linked immunosorbent assay (V3-EIA) for human immunodeficiency virus type 1 (HIV-1) subtyping in Thailand using heteroduplex mobility assay (HMA) as the reference standard. Paired peripheral blood mononuclear cells (PBMC) and sera were collected from 38 HIV-1 seropositive persons in Thailand. HMA was done by standard methods; differential PCR employs primer pairs that differentially amplify either subtype E or B. V3-EIA used peptides specific for subtypes E or B. Thirty-two cases (84%) were found by HMA to be infected with subtype E: and six with (16%) subtype B. The results obtained with differential PCR were 100% concordant with those of HMA; V3 EIA correctly predicted the subtype in 95% (36 of 38). Six samples that molecularly subtyped as E were repeatedly dual reactive by screening V3-EIA, but these resolved to subtype E using an antigen-limiting EIA. Two samples were serologically nontypeable because of overall low levels of V3 antibody. Using HMA as the standard, differential PCR was shown to subtype HIV-1 reliably from patient PBMC samples. V3-EIA correctly predicted HIV-1 subtype in most (95%) of our cases. Because of the less rigorous sampling requirements, specimen processing, and logistical and technical requirements of serotyping compared with molecular techniques, it appears to be practical for screening purposes in a field environment. Samples that cannot be definitively subtyped serologically should undergo differential PCR and antigen-limiting V3 EIA. These approaches to HIV-1 subtyping should be used in complementary fashion in Thailand, where subtypes B and E are currently known to cocirculate.

The effect of Edmonston-Zagreb and Schwarz measles vaccines on immune response in infants

The effects of measles immunization on immune responses in infants and the roles of vaccine strain and age of immunization are not known. Eighty-eight children were immunized at 6 or 9 months of age with the Edmonston-Zagreb (EZ) or Schwarz (SW6, SW9) strain of measles vaccine. Children were studied before and 2 weeks and 3 months after immunization. Seroconversion was similar, but geometric mean neutralizing titers at 3 months differed by vaccine group: SW9, 1367 mIU/mL; SW6, 982; and EZ, 303 (P = .003). Mitogen-induced lymphoproliferation was decreased at 2 weeks in the SW9 group and at 3 months in all groups and was negatively correlated with measles antibody level at 3 months (r = -.387, P = .003). CD8 T cells, soluble CD8, neopterin, and beta2-microglobulin were increased at 2 weeks in the SW9 group, and soluble CD8 and beta2-microglobulin remained elevated at 3 months. Therefore, measles immunization resulted in suppression of lymphoproliferation, which was most evident in infants with the highest antibody responses and most immune activation.

Measles antibody in vaccinated human immunodeficiency virus type 1-infected children

OBJECTIVES

The goals of this study were to evaluate the proportion of previously vaccinated human immunodeficiency virus (HIV) type 1-infected children with detectable postvaccination measles antibody; to assess risk factors for vaccine failure; and to evaluate the response to reimmunization.

METHODS

A total of 81 perinatally HIV-infected children receiving medical care in the Bronx, New York who had previously received measles vaccine were enrolled. The Centers for Disease Control and Prevention (CDC) HIV class, lymphocyte subsets, and measles antibody were determined upon enrollment. Additional data abstracted from medical records included dates and number of prior measles vaccinations and CDC HIV class at the time of vaccination. Measles antibody was determined by microneutralization enzyme-linked immunosorbent assay (ELISA).

RESULTS

The median age at time of study was 42 months (range, 9 to 168 months). Overall, 58 (72%) subjects had detectable measles antibody (microneutralization ELISA titer > 1:5). Children studied within 1 year of vaccination were more likely to have detectable measles antibody than children evaluated more than 1 year after vaccination (83% vs 52%, P < .01). The proportion of children with detectable measles antibody was higher among children with no or moderate immunosuppression compared to those with severe immunosuppression when immune status was based on CD4%. Children vaccinated at 6 to 11 months of age appeared to have a higher proportion of detectable measles antibody than those who received a first measles vaccination after age 1. Only 1 (14%) of 7 previously vaccinated children who were seronegative or had very low titers experienced a four-fold rise in measles antibody when reimmunized.

CONCLUSION

These results support current recommendations to vaccinate HIV-infected children against measles. The proportion of children with detectable measles antibody among vaccinated HIV-infected children is considerably lower than in vaccinated healthy children. HIV-infected children may respond better to measles vaccine when it is administered before the first birthday. From our limited data it appears that reimmunization of previously vaccinated HIV-infected children with moderate to severe immunosuppression does not result in an antibody recall response.

An evaluation of measles revaccination among school-entry-aged children

BACKGROUND

A two dose measles vaccination schedule is recommended routinely for all school-entry-aged children. We evaluated this recommendation by determining both measles antibody seroprevalence and the response to revaccination in seronegative children in this age group.

METHODS

Children 4 to 6 years of age who had received a single dose of measles vaccine between the ages of 15 to 17 months were tested for measles antibody by using enzyme-linked immunosorbent assay (ELISA) microneutralization technique. Seronegative children were revaccinated and again tested for measles antibody (immunoglobulin M [IgM] and neutralizing).

RESULTS

Of 679 children tested, 37 (5.4%) were seronegative. Seronegativity was not significantly associated with age, sex, race, age at initial vaccination, time since vaccination, or maternal year of birth. However, children mothers with a college degree were 12 times more likely to be seronegative than children of mothers who never attended college (P < .01). Of the 37 seronegative children, 36 seroconverted after revaccination--33 producing IgM measles antibody, suggestive of a primary immune response. The cost per seroconversion would have been an estimated $415 if all 679 children had been revaccinated.

CONCLUSIONS

Revaccination reduces the pool of children who are susceptible to measles. Although the cost per seroconversion is high, a two-dose schedule should reduce the substantial costs of controlling measles out breaks by reducing the number of outbreaks.

Correlates of HIV-1 seropositivity among young men in Thailand

Geographic and demographic correlates of risk for HIV-1 seropositivity were studied in 120,216 young men selected by lottery for service in the Royal Thai Army (RTA). The study population consisted of men selected between November 1991 and May 1993. Venous blood was collected at induction, and a brief demographic questionnaire was administered. HIV-1 seropositivity was established by Western blot confirmation of duplicate reactive ELISAs. Geographic variable provided the strongest correlate of risk, clearly distinguishing residents of the upper north, Bangkok, and the central region from the northeast. Overall 12.2% of men from the upper north were HIV-positive. Men who had lived in rural areas were at less risk in most regions of the country, but had equal risk in the upper north. Unmarried men and those with less education were at higher risk throughout the country. These data provide valuable information on the prevalence of HIV infection in one segment of the general population. Continued surveillance of this group will facilitate evaluation of Thailand's response to the epidemic.

Antibody response to measles-mumps-rubella vaccine of children with mild illness at the time of vaccination

OBJECTIVE

To examine the response to measles-mumps-rubella (MMR) vaccine among children with and without mild illness.

DESIGN

Prospective cohort.

PARTICIPANTS

A total of 386 children aged 15 to 23 months.

MAIN OUTCOME MEASURES

Seroconversion rates to measles, mumps, and rubella in ill and well children.

SETTING

Six public health immunization clinics in two counties in the greater metropolitan Atlanta, Ga, area from February 1992 to April 1993.

RESULTS

Acute upper respiratory tract infection, otitis media, and diarrhea were observed in 128 (33%), 41 (11%), and 13 (3%) of the children (groups are not mutually exclusive); 157 children had one of these mild illnesses and 229 were well. Overall seroconversion rates were 98% for measles, 83% for mumps, and 98% for rubella antigens. Measles seroconversion rates for ill children compared with well children, respectively, were as follows: upper respiratory tract infection, 99% vs 97%; mild fever, 98% vs 97%; otitis media, 98% vs 98%; diarrhea, 100% vs 98%; and any mild illness, 99% vs 97%. Estimates of the magnitude of antibody response to measles, mumps, and rubella antigens were the same for children with and without mild illness. There was no association of mild illness with increased rates and severity of adverse events reported in the 2 weeks after vaccination.

CONCLUSIONS

Vaccinating children who present with mild illnesses with MMR vaccine is a safe and efficacious practice. These results support recommendations of the Advisory Committee on Immunization Practices and the American Academy of Pediatrics.

Changing levels of measles antibody titers in women and children in the United States: impact on response to vaccination. Kaiser Permanente Measles Vaccine Trial Team

OBJECTIVES

In the United States, younger women are more likely to have immunity to measles from vaccination and are less likely to have been exposed to the wild virus than are older women. To evaluate changes in measles antibody titers in women in the United States and children's responses to measles vaccination, we analyzed data from a measles vaccine trial.

METHODS

Sera collected from children before vaccination at 6, 9, or 12 months of age and from their mothers were assayed for measles antibodies by plaque reduction neutralization. Responses to vaccination with Merck Sharp & Dohme live measles virus vaccines at 9 months (Attenuvax) and 12 months (M-M-R II) were also analyzed.

RESULTS

Among women born in the United States (n = 614), geometric mean titers (GMTs) of measles antibodies decreased with increasing birth year. For those born before 1957, 1957 through 1963, and after 1963, GMTs were 4798, 2665, and 989, respectively. Among women born outside of the United States (n = 394), there were no differences in GMTs by year of birth. Children of younger women born in the United States were less likely than those of older women to be seropositive at 6, 9, or 12 months. The response to the vaccines varied by maternal birth year for children of women born in the United States. Among 9-month-old children, 93% of those whose mothers were born after 1963 responded, compared with 77% and 60% of those whose mothers were born in 1957 through 1963 and before 1957, respectively. Among 12-month-old children, 98% of those born to the youngest mothers responded, compared with 90% and 83% of those whose mothers were born in 1957 through 1963 and before 1957. The responses of children of women born outside of the United States were not associated with maternal year of birth.

CONCLUSIONS

An increasing proportion of children in the United States will respond to the measles vaccine at younger ages because of lower levels of passively acquired maternal measles antibodies.

Declining prevalence of HIV-1 infection in young Thai men

OBJECTIVE

To evaluate trends in HIV-1 seroprevalence in Thailand.

DESIGN

HIV-1 serosurvey of successive cohorts of young Thai men entering service with the Royal Thai Army (RTA) between November 1989 and November 1994.

METHODS

In November 1989, the RTA Medical Department began routine HIV-1-antibody screening of men who were selected by lottery for conscription. Between November 1989 and November 1994, 311,108 young men were screened at induction. Demographic data were collected between November 1991 and May 1993 and again in November 1994.

RESULTS

The seroprevalence of HIV-1 among conscripts nationwide increased rapidly from 0.5% in 1989 to 3.5% in 1992 and reached 3.7% in 1993. In 1994, the overall prevalence decreased to 3.0%. The decrease was greatest in the upper North (from 12.4% in 1992 to 7.9% in 1994), where the prevalence has been the highest. However, decreases were observed in men from all regions of residence in the country, from both rural and urban areas, and at all educational levels.

CONCLUSIONS

The decline in prevalence suggests declining incidence and that HIV control programs in Thailand are having an impact on the HIV epidemic.

The effect of dose and strain of live attenuated measles vaccines on serological responses in young infants

High morbidity and mortality from measles among infants under 9 months of age is an obstacle to measles control in many developing countries. In this paper, we review 30 studies conducted on the serological response to measles vaccine in infants aged less than 9 months. Among children aged under 9 months, Edmonston Zagreb and AIK-C vaccines produce higher seroresponse rates than Schwarz vaccine of equivalent titre. For Edmonston Zagreb and Schwarz vaccine, seroresponse rates increase with increasing vaccine titre. The absolute rate of seroresponse to Edmonston Zagreb vaccine in 6-month old infants varied greatly between studies because of differences in methods of vaccine titer measurement, serological assays, definitions of seroresponse, and maternal antibody profiles of the populations studied. Seroconversion rates to Edmonston Zagreb or AIK-C vaccines at 6 months of age were generally similar to those to Schwarz vaccine at 9 months of age, but antibody levels were lower after vaccination below 9 months of age. Although the increased mortality documented in other studies after use of high titer vaccines in 4-6 month old infants led to withdrawal of these vaccines, this review of vaccine trials highlights the need for standardization of study methods and for a better understanding of the biological action of measles vaccines.

Immunogenicity of high-titre AIK-C or Edmonston-Zagreb vaccines in 3.5-month-old infants, and of medium- or high-titre Edmonston-Zagreb vaccine in 6-month-old infants, in Kinshasa, Zaire

The effect of measles vaccine potency was evaluated among 485 children aged 6 months, and the effect of vaccine strain was evaluated among 538 children aged 3.5 months, in Kinshasa, Zaire. Children aged 6 months were randomly assigned to receive either high-titre Edmonston-Zagreb (EZ-H), potency 5.7 log10/dose, or medium-titre EZ (EZ-M), potency 4.7 log10/dose, those aged 3.5 months were randomly assigned to receive either AIK-C, potency 5.5 log10/dose, or EZ-H, and were revaccinated with EZ-M vaccine at age 9.5 months. Measles antibodies were measured using the plaque reduction neutralization assay. Among children vaccinated at age 6 months, the seroresponse was significantly higher after EZ-H than EZ-M vaccine, with 92 and 83% seroconverting by 6 months postvaccination and 59 and 40% respectively having antibody titres > 200 mIU. Among children vaccinated at age 3.5 months, only 24% (AIK-C) and 22% (EZ-H) attained antibody titres > or = 200 mIU 6 months postvaccination. After revaccination at age 9.5 months, 81% of children in the AIK-C group and 73% in the EZ-H group had antibody levels > 200 mIU (p = 0.056). A retrospective survey was conducted in January 1993 to determine the mortality experience of vaccine groups, and information was obtained for 94% of the children. A total of 44 deaths (4%) were identified, with no significant differences between groups when stratified by age at vaccination.(ABSTRACT TRUNCATED AT 250 WORDS)