Suburban sprawl and physical and mental health

OBJECTIVE

To study the association between objective measures of suburban sprawl and chronic medical conditions and mental health disorders in the USA.

METHODS

Cross-sectional analysis of survey data merged with objective measures of suburban sprawl. Outcomes are self-reported medical conditions, mental health disorders and health-related quality of life.

RESULTS

Sprawl significantly predicts chronic medical conditions and health-related quality of life, but not mental health disorders. An increase in sprawl from one standard deviation less to one standard deviation more than average implies 96 more chronic medical problems per 1000 residents, which is approximately similar to an aging of the population of 4 years.

CONCLUSIONS

A robust association between sprawl and physical (but not mental) health suggests that suburban design may be an important new avenue for health promotion and disease prevention.

Idiopathic pneumonia syndrome after bone marrow transplantation: the role of pre-transplant radiation conditioning and local cytokine dysregulation in promoting lung inflammation and fibrosis

Pulmonary complications and graft-vs.-host disease (GVHD) remain severe threats to survival after bone marrow transplantation (BMT). Idiopathic pneumonia syndrome (IPS) accounts for nearly 50% of all the cases of interstitial pneumonitis after BMT. IPS is characterized by an early inflammatory phase followed by chronic inflammation and fibrosis of lung tissue; however, the immunopathogenesis of this disease is not yet clearly understood. This biphasic syndrome has been reported to be associated with pre-transplant radiation conditioning in some studies while others have suggested that GVHD or autoimmune phenomena may be responsible for its development. The early post-BMT phase is characterized by the presence of inflammatory cytokines whose net effect is to promote lymphocyte influx into lungs with minimal fibrosis, that leads to an acute form of graft-vs.-host reaction-mediated pulmonary tissue damage. Gradual changes over time in leucocyte influx and activation lead to dysregulated wound repair mechanisms resulting from the shift in the balance of cytokines that promote fibrosis. Using data from new animal models of IPS and information from studies of human IPS, we hypothesize that cytokine-modulated immunological mechanisms which occur during the acute and chronic phases after bone marrow transplantation lead to the development of the progressive, inflammatory, and fibrotic lung disease typical of idiopathic pneumonia syndrome.

Bleomycin-induced pulmonary fibrosis is independent of eosinophils

Eosinophils have been shown to increase in tissues during many fibrotic conditions and consequently have been suggested to contribute to the development of fibrosis. This study tested the hypothesis that eosinophils are essential in the development of lung fibrosis in mice in response to bleomycin (BLM). Anti-IL-5 antibody was administered intraperitoneally into mice 2 h prior to endotracheal BLM inoculation and thereafter, every other day. Lung eosinophilia was evaluated by measurement of eosinophil peroxidase activity and confirmed by eosinophil counts in histologic sections. Lung fibrosis was evaluated by hydroxyproline content and confirmed by collagen staining in histological sections. Results demonstrated that BLM induced pronounced lung eosinophilia, which was maximal 7 days after BLM treatment and remained elevated through day 14, in C57B1/6 SCID mice and CBA/J mice. In contrast, eosinophilia was a minor component in the lungs of wildtype C57B1/6 mice after BLM treatment, although lung fibrosis developed similarly in all three strains of mice. Treatment with anti-IL-5 completely abrogated eosinophilia but failed to block pulmonary fibrosis induced by BLM in all mouse strains, including C57B1/6 SCID, wildtype C57B1/6 mice, and CBA/J mice. Analysis of cytokine mRNA by RNase-protection assay in C57B1/6 SCID mice indicated that BLM treatment caused enhanced expression of the cytokines, TNF-alpha, and IL-6 at days 3, 7, and 14 post-BLM inoculation, regardless of whether eosinophils were depleted by anti-IL-5. Finally, the importance of eosinophils in lung fibrosis was examined in IL-5 gene knockout mice (IL-5tm1Kopf). BLM treatment induced significant lung fibrosis in IL-5 knockout mice in the absence of eosinophilia. These findings indicate that eosinophils are not an absolute requirement for BLM-induced pulmonary fibrosis in the mouse.

Participation in a school-based sexually transmitted disease screening program

BACKGROUND

A school-based chlamydia screening program was offered repeatedly in three Louisiana public high schools in an effort to expand sexually transmitted disease screening services for adolescents.

GOAL

To describe participation of a fixed cohort of students to elucidate the impact of screening on chlamydia prevalence.

STUDY DESIGN

Five opportunities for chlamydia testing were offered in 3 schools during 3 school years (1995-1996, 1996-1997, 1997-1998). Only students with parental consent could be tested. Students consistently enrolled during the 3 years (n = 1475) were included in this analysis.

RESULTS

During the 3 school years, parental consent was cumulatively obtained for 1443 students (97.8%), and 1305 students (88.5%) were tested at least once. Of those tested, 81.1% tested more than once. The prevalence of Chlamydia trachomatis infection at first test among students who tested more than once was 1.8% for males and 7.7% for females. Among students tested only once, 6.2% of males and 12.7% of females had chlamydial infection. Among students tested more than once, no significant difference in C. trachomatis prevalence was associated with repeat screenings. Incidence rates per 1000 person-months were 4.3 (2.2, males; 7.1, females; P < 0.0001). Reinfections explained only 5.6% of all incident cases.

CONCLUSION

The documented high response from both parents and students to this school-based chlamydia screening program offers great promise for sexually transmitted disease control among adolescents. Overall, C. trachomatis prevalence was two times higher among students testing only once than among those testing more than once. Routine and continued availability of school-based chlamydia screening programs can potentially reduce the burden of disease among adolescents.

Strategies for syphilis prevention: findings from surveys in a high-incidence area

BACKGROUND

The persistence of syphilis in the United States suggests that a better understanding is needed of the potential for various public health approaches to prevent the spread of the disease.

STUDY DESIGN

The authors conducted surveys of 92 persons with early syphilis, 56 uninfected sexual contacts, and 143 neighborhood controls in the Baton Rouge, Louisiana area. The surveys collected information regarding sexual behavior, access to and use of healthcare services, encounters at sites at which serologic screening for syphilis could be done, and exposure to interventions designed to prevent HIV infection.

RESULTS

All groups reported high-risk sexual behavior. Cases and contacts were more likely than controls to report two or more sex partners in the previous year, but the three groups were similar in the percentage reporting five or more sex partners. Cases had poor access to health care and by some measures this access was less than that of controls. The potential screening site visited most frequently by cases was the public hospital emergency room (40%). Cases were less likely to have been exposed to programs designed to prevent HIV infection than uninfected contacts and controls combined (odds ratios, 0.51-0.66).

CONCLUSIONS

Persons with syphilis were not unlike others in their neighborhoods, suggesting that syphilis is a sentinel event that indicates an entire neighborhood is at risk. Improvements in access to health care for sexually transmitted disease-related symptoms, screening in sites such as public hospital emergency rooms, and emphasizing sexual risk-reduction interventions may limit the spread of syphilis in these neighborhoods. To prevent syphilis in the long term, public health programs should also try to better understand and change other community-level socioeconomic factors that influence sexual behavior.

Evidence of a structural effect for alcohol outlet density: a multilevel analysis

BACKGROUND

Ecological studies reveal that alcohol-related outcomes tend to occur in high alcohol outlet density neighborhoods. The ecological design of these studies limits the interpretation of the findings in terms of the level of the effect. The effect of alcohol outlet density could be related to greater individual access to alcohol, an individual level effect, or to the grouping of drinkers by neighborhood, a structural effect at the neighborhood level.

METHODS

To differentiate between individual and neighborhood level possibilities, we conducted a multilevel study. Individual distance to the closest alcohol outlet was the individual level measure of the effect of alcohol outlet density, whereas the mean distance to the closest alcohol outlet for all individuals within a census tract was the neighborhood level measure for the effect of alcohol outlet density. We analyzed telephone surveys of 2604 telephone households within 24 census tracts stratified by poverty status and alcohol outlet density. Individual distance to alcohol outlets, age, sex, race/ethnicity, and level of education were entered as individual level covariates, and their corresponding aggregated means were entered as census tract level covariates (i.e., mean distance to outlets, mean age, percentage male, percentage Black, mean education).

RESULTS

Analysis of variance revealed that 16.2% of the variance in drinking norms and 11.5% of the variance in alcohol consumption were accounted for at the census tract level. In multivariate hierarchical analysis, individual distance to the closest alcohol outlet was unrelated with drinking norms and alcohol consumption, whereas mean distance to the closest alcohol outlet demonstrated a negative relation with drinking norms (betae = -5.50+/-2.37) and with alcohol consumption (betae = -0.477+/-0.195); that is, the higher the mean distance to the closest alcohol outlet, the lower the mean drinking norms score and mean level of alcohol consumption.

CONCLUSIONS

The findings suggest that the effect of alcohol outlet density on alcohol-related outcomes functions through an effect at the neighborhood level rather than at the individual level. Problem drinkers tend to be grouped in neighborhoods, an effect predicted by alcohol outlet density.

A structural model of health behavior: a pragmatic approach to explain and influence health behaviors at the population level

BACKGROUND

Behavior is influenced by individual-level attributes as well as by the conditions under which people live. Altering policies, practices, and the conditions of life can directly and indirectly influence individual behavior. This paper builds on existing ecological theories of health behavior by specifying structural mechanisms by which population-level factors effect change in individual health behaviors.

METHODS

This paper moves ecological theory from model building to a pragmatic characterization of structural interventions. We examined social and environmental factors beyond individual control and mechanisms as to how they influence behavior.

RESULTS

Four categories of structural factors are identified: (1) availability of protective or harmful consumer products, (2) physical structures (or physical characteristics of products), (3) social structures and policies, and (4) media and cultural messages. The first three can directly influence individuals through facilitating or constraining behavior. The fourth, media, operates by changing individual-level attitudes, beliefs, and cognitions, as well as group norms.

CONCLUSION

Interventions that target the four identified structural factors are a means to provide conditions that not only reduce high-risk behavior but also prevent the adoption of high-risk behaviors. Structural interventions are important and underutilized approaches for improving our nation's health.

An STD/HIV prevention intervention framework

Historically, interventions to prevent STD/HIV transmission have been categorized by program methodology rather than defining the content and nature of the intervention. A new taxonomy is needed to help expand the scope of interventions that can be used to prevent STD and HIV transmission. The taxonomy defines two major types of interventions, individual-level and structural level. The former targets risk factors attributable to individuals. Structural interventions target conditions outside the control of the individual. Individual-level interventions focus on counseling, screening, and treatment. They include psychological and biological interventions. Structural-level interventions address accessibility of relevant consumer products (condoms, needles), physical structures (e.g. blighted and abandoned housing, lighting, design of social facilities), social structures (policies that facilitate or constrain behaviors such as supervision of youth, and enforcement of alcohol beverage laws); and media messages (messages and images in the broadcast and print media that portray high-risk behaviors as positive and without serious consequences). A new taxonomy not only clarifies the content of preventive interventions but highlights neglected strategies involving individual biological interventions and structural interventions to prevent STD/HIV transmission.

Role of virus replication in a murine model of AIDS-associated interstitial pneumonitis

One of the major complications of HIV infection is the development of interstitial pneumonitis (IP). IP is characterized by lymphocytic infiltration of the lung and may lead to respiratory failure in some cases. The etiology of IP is unknown although it is likely the result of an antiviral or autoimmune response occurring in the lung. To determine the role of viral replication in the development of IP, AZT was evaluated for the ability to inhibit development of lung inflammation in a murine model of retrovirus-associated IP. Mice were infected with LP-BM5 retrovirus, which induces murine AIDS. Infected mice develop IP by 4 weeks postinfection characterized by infiltration of the lung with activated T cells, B cells, and macrophages. Virus could be detected in the lungs of these mice by 2 weeks postinfection and persisted throughout the course of disease. To determine if reduction in viral load affected the disease process, infected mice were treated with AZT for varying periods postinfection and analyzed for the development of IP. Treatment with AZT resulted in a treatment time-dependent reduction of viral RNA in the lungs of infected mice compared to untreated infected mice. The reduction of viral burden in the lungs correlated with a reduction in the severity of IP and decreased production of the proinflammatory cytokines interleukin (IL)-1 beta and interferon (IFN)-gamma. These results suggest that continuous viral replication in the lung contributes to the pathogenesis of IP.

Role of T cell subsets in the development of AIDS-associated interstitial pneumonitis in mice

Idiopathic interstitial pneumonitis (IP), characterized by lymphocytic infiltration of the lung and pulmonary dysfunction, is a major noninfectious complication of human immunodeficiency virus (HIV) infection. The role of the CD4+ and CD8+ T cell populations and INF-gamma in the development of IP were analyzed using a murine model of retroviral-associated IP. Infected mice depleted of CD8+ T cells developed IP similarly to untreated infected mice, suggesting that the CD8+ T cell population does not play a role in IP. Furthermore, depletion of CD8+ T cells did not alter the level of viral RNA in lungs, suggesting that cytotoxic T cells may not serve a role in controlling virus burden in lungs. In contrast, depletion of CD4+ T cells in infected mice prevented the development of IP and inhibited inflammatory cytokine expression, suggesting that CD4+ T cells are important for the development of IP. IFN-gamma -/- mice infected with virus for 10 weeks developed IP, although the severity of lymphocytic infiltration was substantially reduced compared to infected wild-type mice. The data suggest that persistent viral antigen in the lung may drive a CD4+ T cell-mediated immune response, resulting in the chronic production of IFN-gamma which amplifies a chronic inflammatory response in the lung resulting in tissue injury.

Repeated school-based screening for sexually transmitted diseases: a feasible strategy for reaching adolescents

OBJECTIVES

To determine whether repeated school-based screening and treatment for chlamydia and gonorrhea will decrease the prevalence of infection among students.

DESIGN

At three high schools serving over 2000 students, all 9th through 12th grade students were given the opportunity to be tested during three consecutive school years for chlamydia and gonorrhea, using urine ligase chain reaction tests. Five comparable schools with 5063 students enrolled served as wait-listed controls.

SETTING

Eight urban public high schools in Louisiana.

PARTICIPANTS

Annually, 52% to 65% of all enrolled students participated; among those enrolled in schools for > or = 2 years, 83.4% of students were tested at least once.

INTERVENTION

Education of all students; counseling and treatment of infected students with oral single-dose antibiotic therapy.

MAIN OUTCOME MEASURE

Prevalence of Chlamydia trachomatis and gonorrhea infection.

RESULTS

At first test, 286 (11.5%) of 2497 girls and 143 (6.2%) of 2308 boys were infected with chlamydia, and 48 (2.5%) of 1883 girls and 19 (1.2%) of 1628 boys had gonorrhea. Over 90% of infections were asymptomatic. With repeated testing, chlamydia prevalence among boys dropped to half the rate of comparison schools (3.2% vs 6.4%). Among girls chlamydia prevalence declined only slightly (10.3% vs 11. 9% in comparison schools).

CONCLUSION

There are high rates of asymptomatic sexually transmitted diseases (STDs) in the general urban school population. Repeated screening and treatment are associated with declines in chlamydia prevalence among boys. Expansion of STD screening and treatment programs to school settings is likely to be a critical component of a national strategy to control bacterial STDs.

School-based screening for sexually-transmitted diseases

Chlamydia and gonorrhea are the two most common bacterial sexually transmitted diseases (STDs) disproportionately affecting adolescents. Compared to other states, in 1997, Louisiana ranked fifth and seventh in reported case rates of gonorrhea and chlamydia, respectively. These two diseases can now be diagnosed with a urine test using DNA amplification technology, making it possible to identify asymptomatically infected persons without having to conduct a physical examination. In a school screening program piloted in Louisiana school-based health centers, all students in 12 urban public high schools were offered the urine test. Most infected students had no symptoms. The infection rate in girls was generally at least twice as high as among boys. Over time, the prevalence of chlamydia infection decreased. School-based screening is feasible and acceptable and can identify a large number of asymptomatic, infected youth. Screening programs which target asymptomatic youth should be expanded in order to reduce the burden of chlamydia and gonorrhea in our communities.

Condom availability for HIV/STD prevention

Condom availability is a structural intervention that increases access to condoms. It is the most important strategy for the prevention of the sexual transmission of HIV/STDs in developing countries. While it is an integral component of many prevention programs, it is considered controversial in high school settings and its role in a variety of HIV/STD prevention interventions has been understudied, understated, and/or unacknowledged. Condom availability as an HIV/STD prevention strategy needs to be reprioritized and should be considered a critical foundation of all programs to prevent the sexual transmission of HIV.

Idiopathic pneumonia syndrome after allogeneic bone marrow transplantation in mice. Role of pretransplant radiation conditioning

Idiopathic pneumonia syndrome (IPS) is a significant clinical problem encountered among patients treated with bone marrow transplantation (BMT). IPS is identified as an inflammatory lung disease characterized by diffuse interstitial pneumonitis and alveolitis leading to interstitial fibrosis in the absence of an identifiable infectious agent. In an earlier study we characterized a murine model of IPS following allogeneic BMT that exhibits several features of human IPS. In this report we show that the lung represents a unique target of post-BMT disease in this model. The kinetics of developing lung disease were found to be markedly different from the kinetics of graft-versus-host disease in other tissues such as liver, colon, ear, skin, and tongue. Mice transplanted by our standard protocol with T-cell-depleted semiallogeneic donor bone marrow plus donor spleen cells in the absence of pretransplant radiation conditioning did not develop lung inflammation or fibrosis characteristic of IPS. Pretransplant radiation conditioning in the absence of BMT also failed to cause IPS, demonstrating an important role for radiation conditioning in the development of BMT-related IPS. The occurrence of lung disease post-BMT was found to be dependent on radiation conditioning in a dose-dependent manner. Finally, thoracic irradiation alone was demonstrated to be sufficient in causing IPS in mice transplanted with bone marrow plus spleen cells, albeit with reduced severity. Based on these findings, we conclude that pretransplant radiation conditioning plays an important role in the development of IPS following allogeneic BMT.

Implementation of condom social marketing in Louisiana, 1993 to 1996

OBJECTIVES

This article describes the implementation and impact of the first statewide condom social marketing intervention in the United States.

METHODS

A statewide social marketing program made condoms freely available in 93 public health clinics, 39 community mental health centers, 29 substance abuse treatment sites, and more than 1000 businesses in neighborhoods with high rates of sexually transmitted diseases (STDs) and HIV. Surveys about condom use were conducted annually.

RESULTS

Between 1994 and 1996, more than 33 million condoms were distributed without significant opposition. Over time, self-reported condom use at the last sexual encounter increased among African American women (from 28% in 1994 to 36% in 1996), particularly African American women with 2 or more sex partners (from 30% to 48%). Condom use at the last sexual encounter increased among African American men (from 40% in 1994 to an average of 54% in 1996). The number of reported sex partners did not increase.

CONCLUSIONS

Condom social marketing can be successfully implemented in the United States. The widespread availability of free condoms is associated with increased condom use, particularly among persons at high risk for STDs and HIV.

T cell independence of bleomycin-induced pulmonary fibrosis

The role of T cells and cytokines in bleomycin (BLM)-induced fibrosis was evaluated in susceptible and resistant strains of normal and SCID mice. Histology and hydroxyproline analysis showed that BLM induced pulmonary fibrosis in C57BL/6 and (C57BL/6 x BALB/c)F1 mice, whereas BALB/c mice were resistant to the disease. To test whether lymphocytes were required for the induction of BLM-induced pulmonary fibrosis, SCID mice were injected intratracheally with BLM and evaluated for the development of pulmonary inflammation and fibrosis. Similar morphological changes and increases in hydroxyproline were observed in both C57BL/6 SCID and (C57BL/6 x CB.17)F1 SCID animals compared to those seen in wild-type C57BL/6 and (C57BL/6 x BALB/c)F1 mice. In contrast, CB.17 SCID mice, which are genetically similar to BALB/c mice, were resistant to disease induction. Analysis of the cellular infiltrate in BLM-treated C57Bl/6 SCID mice confirmed a lack of T cells in the lungs of SCID mice and demonstrated a pronounced accumulation of eosinophils in areas of developing pulmonary fibrosis. NK cells were significantly elevated in untreated SCID mice and did not increase further after BLM treatment. Analysis of selected cytokines 1 day after initiation of BLM-induced pulmonary fibrosis indicated that the levels of TNF-alpha and IFN-gamma appeared to segregate with fibrosis in both the SCID and wild-type mice. The data demonstrate that T cells are not required for the induction of fibrosis by BLM and suggest that responses by non-lymphoid cells may be sufficient for the induction of fibrosis.

Evaluation of the Gen-Probe PACE 2 assay for the detection of asymptomatic Chlamydia trachomatis and Neisseria gonorrhoeae infections in male arrestees

BACKGROUND

The LET and Gen-Probe PACE 2 assay are used to screen male arrestees for evidence of infection with chlamydia and gonorrhea in the intake/booking area of the Jefferson Parish Correctional Center.

GOAL OF THIS STUDY

To determine the accuracy of the Gen-Probe PACE 2 assay for the detection of asymptomatic infection with Chlamydia trachomatis and Neisseria gonorrhoeae infections in male arrestees.

STUDY DESIGN

From December 1993 to March 1994, 196 arrestees younger than 22 years were screened with the Gen-Probe PACE 2 assay and McCoy shell vial culture for Chlamydia trachomatis. From April to October 1994, 444 arrestees of all ages were screened with the Gen-Probe PACE 2 assay and standard culture for Neisseria gonorrhoeae. The sensitivity, specificity, and predictive values of the Gen-Probe PACE 2 assay, compared with culture, were calculated with 95% confidence intervals.

RESULTS

The Gen-Probe PACE 2 assay compared with culture had a sensitivity, specificity, and positive predictive value for Chlamydia trachomatis of 84%, 99%, and 93% and for Neisseria gonorrhoeae of 54%, 99.5%, and 78%.

CONCLUSION

The Gen-Probe PACE 2 assay is useful for screening young males in this jail setting and is more accurate for detecting Chlamydia trachomatis compared with Neisseria gonorrhoeae.

A geographic relation between alcohol availability and gonorrhea rates

BACKGROUND AND OBJECTIVES

The availability of alcohol measured as alcohol outlet density is associated with numerous alcohol-related outcomes in small area analysis. A number of studies suggest that high-risk sexual behavior should also be considered an alcohol-related outcome.

GOAL OF THIS STUDY

To assess the geographic relationship between alcohol availability and high-risk sexual behavior at the neighborhood level.

STUDY DESIGN

Ecological analysis of the geographic relation between off-premise, on-premise, and total alcohol outlet density and reported gonorrhea rates among 155 urban residential census tracts in New Orleans during 1995.

RESULTS

All alcohol outlet density variables were positively related to gonorrhea rates. Off-premise outlets per square mile was most strongly related to gonorrhea rates (beta +/- SE) (beta = 0.582+/-0.073), accounting for 29% of the variance in gonorrhea rates. Interpreted as an elasticity, a 10% increase in off-sale alcohol outlet density accounts for a 5.8% increase in gonorrhea rates. Including the covariates percent black and percent unemployed to the model reduced but did not remove the effect of off-sale outlet density (beta = 0.192+/-0.047).

CONCLUSIONS

These results indicate there is a geographic relationship between alcohol outlet density and gonorrhea rates at the census tract level. Although these results cannot be interpreted causally, they do justify a public health intervention as a next step in defining the relation between alcohol availability and high-risk sexual behavior.

Attitudes and compliance of pre-adolescent children during early treatment of Class II malocclusion

A survey was administered to 168 parents and their children at the end of mixed dentition treatment for Class II correction utilizing bionators and headgears to investigate attitudes of parents and patients toward bionators and headgears and to elicit factors associated with compliance. Directional differences between parent and child responses occurred frequently with agreement ranging from 41 to 100%, averaging 69% overall. The results indicate that the orthodontic patient population has medical and dental health as a priority. While parental and child reasons for seeking treatment may be different, it appears that both groups seek care for perceived benefits of health, decreased present and future oral problems, peer influences, and dental self image improvement. Additionally, children who are undergoing treatment perceive that others do not understand what they are going through, they may be embarrassed, and some may break their appliances to annoy the parent or orthodontist. Pain, decreased ability to speak, and difficulty chewing were reported to decrease appliance wear. Patient understanding of the treatment goals was reported to increase compliance. The bionator caused more instances of speech problems and associated non-compliance than the headgear. The headgear caused more instances of pain, but did not cause significantly less associated compliance than the bionator. The results suggest that bolstering the patient-orthodontist relationship, informing the patient about the treatment goals, methods, and their individual role, and offering immediate short term rewards can potentially increase patient compliance.

Idiopathic pneumonia syndrome in mice after allogeneic bone marrow transplantation

Pulmonary complications are a major clinical problem following allogeneic bone marrow transplantation (BMT), contributing to more than 30% of transplant-related mortalities. Idiopathic pneumonia syndrome is responsible for significant mortality among BMT patients. However, the etiology of injury to the lung parenchyma by this disease syndrome is unknown and it has been difficult to evaluate the cellular and molecular mechanisms underlying IPS in the absence of a suitable animal model. To study post-BMT lung disease during graft-versus-host disease (GVHD), we have developed a murine model that utilizes a semi-allogeneic parental --> F1 transplant strategy to induce a mild form of GVHD. Progressive inflammatory lung disease developed in animals with mild GVHD, as indicated by changes in immune cell distribution and cytokine expression in the lungs of transplanted animals. Histologic analysis of lung tissue from GVHD mice at 3 wk post-BMT showed minor immunopathologic changes compared with control mice. In contrast, lungs of GVHD mice at 12 wk displayed histopathologic hallmarks of interstitial pneumonitis, such as prominent perilumenal mononuclear cell infiltration and areas of alveolar congestion. Flow cytometric analysis of lung interstitial cells of GVHD mice revealed an increase in CD8+ T-cells at week 3, which decreased to normal levels by week 12 post-BMT. Simultaneously, the percentage of CD4+ T-cells increased progressively above normal levels and peaked at week 7 post-BMT. Analysis of cytokine mRNA expression in lung tissue indicated that steady state levels of interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, interferon-gamma, and IL-12 were significantly elevated in lungs of GVHD mice at 3 wk post-BMT compared with untreated controls. Mice that were transplanted with allogeneic bone marrow alone (BMT controls) also displayed elevated expression of these cytokines, although only IL-6 was significantly higher than in untreated controls. In contrast, at 12 wk after transplantation only TNF-alpha and IL-12 levels remained elevated in GVHD mice, suggesting prolonged macrophage activation. On the basis of these findings, we conclude that allogeneic bone marrow transplantation in this mouse model causes a progressive interstitial pneumonitis, which is characterized by an acute influx of CD8+ T-cells, followed in the chronic phase by a prominent accumulation of CD4+ T-cells, and is associated with persistent production of cytokines known to activate macrophages.

A school-based Chlamydia control program using DNA amplification technology

OBJECTIVES

Chlamydia trachomatis is the most prevalent bacterial sexually transmitted disease (STD) in the United States, with the highest rates reported among adolescents. Chlamydia has severe consequences including pelvic inflammatory disease and infertility, and is believed to be a cofactor in human immunodeficiency virus transmission. Given that chlamydia is predominantly asymptomatic, most cases are identified through routine screening in health care settings. Over time, screening and treatment appear to be associated with a decrease in the prevalence of disease in areas with consistent chlamydia control programs. The new availability of sensitive and specific urine tests for chlamydia (polymerase chain reaction [PCR] and ligase chain reaction [LCR]) provides the opportunity to screen large numbers of at-risk youth in a noninvasive manner. We used PCR/LCR testing to investigate the feasibility of a school-based chlamydia control program and to determine the prevalence of chlamydia infection among junior and senior high school students.

DESIGN

At three junior/senior high schools, all students, regardless of symptoms or sexual history, were given the opportunity to be tested for chlamydia using urine-based PCR or LCR testing. Only students with parental consent were eligible. Parents could not obtain test results, except if their children told them. During the five 3-week testing periods, throughout the day, classes were escorted to the testing area and each student was individually counseled regarding the opportunity to participate in the testing.

SETTING

Three urban public schools in Louisiana.

PARTICIPANTS

A total of 1933 students in grades 7 through 12, including 861 girls and 1072 boys.

INTERVENTION

All students were informed about the test and taught about chlamydia during the homeroom period. Students were asked to provide a first-void urine specimen of not more than 30 mL. Specimens were refrigerated and delivered to the laboratory on the same day. Infected students were counseled and offered treatment with azithromycin, 1 g orally. They were also referred for or offered additional STD and human immunodeficiency virus testing. Infected students were asked to refer their sex partners to the city STD clinic for treatment.

MAIN OUTCOME MEASURE

Prevalence of C trachomatis infection by grade and gender.

RESULTS

Parental consent was obtained for 2849 (86.9%) of the 3278 matriculated students in grades 7 through 12. Fifty-one parents (1.6%) returned consent forms refusing permission for their child to participate in this screening and treatment program. The remaining 378 (11.5%) could not be reached by mail or telephone. Among all students with consent, 1933 (67.8% of those consented and 59.0% of those matriculated) were tested. Girls were less likely to be tested than boys (861/1363 [63. 2%] vs 1072/1465 [73.2%]). The overall prevalence of C trachomatis was 6.5%, with rates among girls more than twice that of boys (9.7% vs 4.0%). Generally, rates of infection increased with age. The prevalence rates among boys were for 7th grade, 2/208 (1%); 8th grade, 2/196 (2%); 9th grade, 10/236 (4.2%); 10th grade, 12/185 (6. 5%); 11th grade, 8/146 (5.5%); and 12th grade, 9/101 (8.9%). For boys 15 to 19 year old, the prevalence of chlamydia was 5.7%. Among girls, the prevalence rates were 7th grade, 0/105 (0%); 8th grade, 11/166 (6.6%); 9th grade, 23/218 (10.6%); 10th grade 23/146 (15.8%); 11th grade, 13/118 (11%); and 12th grade, 13/107 (12.1%). Among girls 15 to 19 years old, 12.7% were infected. Of 126 infected students, treatment was provided to 111 (88%). For this project, the laboratory cost of LCR testing was $17.76 per test. Without considering clinical staff time to collect the specimens, the average laboratory cost per infected student identified was $272. For students 15 to 19 years of age, of whom 104 (8.9%) of 1170 were infected, the laboratory cost was $200 per case identified.

CONCLUSION

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