Control of nosocomial transmission of multidrug-resistant Mycobacterium tuberculosis among healthcare workers and HIV-infected patients

Control of nosocomial transmission of multidrug-resistant Mycobacterium tuberculosis among healthcare workers and HIV-infected patients

Introduction

Summary From 1988 to 1990, an outbreak of multidrug-resistant tuberculosis (MDR-TB) among patients, and an increased of number tuberculin-skin-test conversions among

healthcare workers, occurred on the HIV ward of Jackson Memorial Hospital, Miami, Florida, USA. Measures similar to those subsequently recommended in the 1990 Centers for Disease Control and Prevention guidelines were implemented on the HIV ward by June, 1990, and in September, 1992, we evaluated the efficacy of these control measures. Among MDR-TB patients and healthcare workers with tuberculin-skin-test conversions on the HIV ward, we looked for evidence of exposure to HIV ward MDR-TB patients positive for acid-fast bacilli in sputum during initial (January-May, 1990) and follow-up (June, 1990-June, 1992) periods. Exposure before implementation of control measures to an infectious MDR-TB patient on the HIV ward was recorded in 12 of 15 (80%) MDR-TB patients during the initial period and 5 of 11 (45%) MDR-TB patients during follow-up. After implementation of control measures, no episodes of MDR-TB could be traced to contact with infectious MDR-TB patients on the HIV ward. Skin-test conversions among workers on the HIV ward declined from 7 of 25 (28%) during the initial period to 3 of 17 (18%) in the early (June, 1990-February, 1991) and 0 of 23 in the late (March, 1991-June, 1992) follow-up periods (p<0·01). Skin-test conversions among healthcare workers were not associated with increased exposure to MDR-TB patients, and were not significantly higher among workers on the HIV ward than on a control ward without tuberculosis patients

(3/27 vs 0/16). These

data demonstrate that implementation of measures similar to the Centers for Disease Control and Prevention 1990 tuberculosis-control guidelines were effective in halting transmission of MDR-TB to healthcare workers and HIV-infected patients. Lancet 1995; 345: 235—40 See

Commentary

page 204

Hospital Infections Program, National Center for Infectious Disease, Mailstop A07, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA (P N Wenger MD, C M Beck-Sague MD, W R Jarvis MD); and Offices of Tuberculosis Control (J Otten RN) and Employee Health (A Breeden RN, D Orfas RN), Jackson Memorial Hospital, Miami, Florida Correspondence to: Dr Peter N Wenger

Nosocomial transmission of tuberculosis to patients in healthcare facilities in the USA used to be rarely reported. Since 1985, a striking increase in the incidence of tuberculosis in the USA has been accompanied by numerous outbreaks of nosocomial tuberculosis due to multidrug-resistant strains of Mycobacterium tuberculosis (MDR-TB).1-7 Patients infected with HIV and M tuberculosis are at increased risk of developing active tuberculosis8 and healthcare workers exposed to patients with MDR-TB are at risk of tuberculosis infection.2-7 The risk of nosocomial MDR-TB transmission is increased because conventional initial antituberculosis chemotherapy is inadequate to treat MDR strains and patients infected with such strains may remain infectious for a long time. Delays in diagnosis of tuberculosis in these patients and delays in determining drug susceptibility, together with inadequate patient isolation precautions, have helped transmission.2-7 Tuberculosis transmission in hospitals has been associated with incomplete implementation of current Centers for Disease Control and Prevention (CDC) recommendations.2,3,5-7 Many USA hospitals seem to have inadequate tuberculosis control programmes or facilities.9 Between June and the end of August, 1990, a team from the CDC helped to investigate an outbreak of MDR-TB at Jackson Memorial Hospital, Miami, Florida. Epidemiological and laboratory evidence documented MDR-TB transmission from patient to patient and patient to healthcare worker on the HIV ward and clinic.2-4 Specific measures similar to those subsequently recommended in the 1990 CDC guidelines were implemented for control of the outbreak and prevention of further nosocomial MDR-TB transmission. 10 We report a follow-up investigation done in September, 1992, to the efficacy of infection-control, environmental, and laboratory modifications in terminating MDR-TB transmission on the HIV ward. assess

Methods Procedural

investigation

To assess changes in infection-control policies and practices, CDC investigators and hospital tuberculosis-control personnel observed patient and healthcare worker behaviour (eg, patients with MDR-TB wearing surgical masks when outside their rooms, workers wearing appropriate respiratory protection when entering tuberculosis isolation rooms) on the HIV ward, and interviewed staff responsible for tuberculosis control and those who worked on the HIV ward. Direction of air flow in all tuberculosis isolation rooms on the HIV ward was evaluated with smoke tubes.

235

Definitions was

defined

as

any

patient

Case ascertainment

Microbiology and infection-control records from Jackson Memorial Hospital and the Florida Department of Health and Services Rehabilitation Mycobacteriology Research and Reference Laboratory were reviewed to identify patients with tuberculosis during the study period. Drug susceptibility records of isolates were reviewed to identify patients with MDR-TB. Medical records of MDR-TB patients were reviewed to verify that their clinical course was consistent with tuberculosis.

Patient-to-patient MDR-TB transmission To find

out

stopped on the HIV ward, we looked for an association between subsequent development of MDR-TB and exposure to MDR-TB patients on the HIV ward who were sputum-smear positive for acid-fast bacilli (AFB) during the follow-up period. An MDR-TB patient was taken to be infectious 2 weeks before and after an AFB-positive sputum smear was obtained. An infectious-MDR-TB-patient-day was defined as any day in which such a patient was present on the HIV ward. Thus, 2 infectious MDR-TB patients present on the HIV ward on the same day would contribute 2 infectious-MDR-TB-patient-days. The medical records of all case-patients were reviewed for potential exposures on the HIV ward during the study period. Data collected included dates and results of AFB smears and cultures, antimicrobial susceptibility of the M tuberculosis isolate, dates of admission and discharge, inpatient ward location, and outcome. We compared case-patient M tuberculosis isolates from the original outbreak investigation and this follow-up study by restriction fragment length polymorphism (RFLP) analysis.3,l1

was

admitted to the HIV January, 1990, and June, 1992 (study period), with an isolate of M tuberculosis that was resistant to at least isoniazid and rifampicin and whose clinical course was consistent with tuberculosis. Although the hospital began implementing control measures in March, 1990, these measures were not fully in place until June, 1990. Therefore, the study period was divided into an initial implementation period (January-May, 1990) and a follow-up period (June, 1990-June, 1992) when control measures were in place. The follow-up period was further divided into the early (June, 1990-February, 1991) and late (March, 1991-June, 1992) phases to evaluate changes in tuberculosis infection control practices made in February, 1991.

A case-patient ward between

whether

patient-to-patient MDR-TB transmission

Healthcare workers To evaluate whether intervention reduced the risk of nosocomial transmission of tuberculosis from patients to healthcare workers, we compared tuberculin-skin-test conversion rates among healthcare workers on the HIV ward in the initial and follow-up periods, and we compared conversion rates among healthcare workers on the HIV ward and a control ward, where tuberculosis patients were not admitted, during the follow-up-period. The

TB=tuberculosis, HCW=healthcare worker, TST =tuberculln skin test. *TB isolation consisted of a private room with at least six air exchanges per h including at least two outside air changes per h and negative pressure with respect to adjacent corndor; tturnaround times estimated by staff of the Office of Tuberculosis Control. Table: Comparison of tuberculosis infection-control measures before and after implementation of the infection control policies on the HIV ward, Jackson Memorial Hospital, January, 1990-June, 1992

236

regimen to include at least four antimicrobial agents (table). Additional improvements implemented during the follow-up period included: maintenance of negative pressure in all designated tuberculosis isolation rooms on the HIV ward, including daily inspection with smoke tubes to ensure negative pressure; increased availability of and shorter turnaround time for AFB smears, M tuberculosis identification, and drug-susceptibility results; and changing the respiratory protection device for healthcare workers from a cup-shaped surgical mask to, initially, a submicron surgical mask.

Figure

1: Number of MDR-TB

patients

on

HIV ward

latter ward had been used as the control ward in the initial outbreak investigation.3 Workers included in the analysis were registered nurses, licensed practical nurses, and ward secretaries. A tuberculin-skin-test conversion was defined as a reaction to five tuberculin units of purified protein derivative of at least 10 mm induration and at least 6 mm larger than any previously reported induration.’,1" Trained personnel applied tuberculin skin tests and examined positive skin reactions. We examined the temporal relation between potential exposure to infectious MDR-TB patients on the HIV ward and the risk of tuberculin-skin-test conversion among healthcare workers. Healthcare workers were taken to be susceptible and included in the analysis if they had a baseline negative tuberculin skin test while working on the HIV or control ward or, if hired during the study period, a negative skin test at time of employment. Tuberculin skin tests were done every 4 months on the HIV ward and every 12 months on the control ward. The susceptible period for a worker who had a skin-test conversion was defined as beginning 10 weeks before his/her last negative test and ending 2 13 weeks before the positive test." An infectious-MDR-TB-patient-exposure-day was defined as any day in which a healthcare worker worked on the HIV ward when an infectious MDR-TB patient was present. Demographic data, including employment and tuberculin-skin-test history, were obtained by review of employee, medical, and attendance records.

Statistical analysis Relative risks (RRs), odds ratios (ORs), and 95% CIs

were

calculated for categorical variables, and the Fisher’s exact or X2 tests were used for significance testing. Continuous variables were compared with the Kruskal-Wallis test for two groups.

Results Infection control policies and practices Improvements in infection control implemented on the HIV ward between the initial and follow-up periods included: higher index of suspicion for tuberculosis and stricter application of isolation criteria; stricter bacteriological and clinical criteria for discontinuing isolation of patients with tuberculosis; restriction of cough-inducing procedures such as sputum induction to tuberculosis isolation rooms; increased frequency of tuberculin skin tests for healthcare workers on the HIV ward; and expansion of the initial tuberculosis treatment

Environmental and observational evaluation All 23 rooms on the HIV ward designated for isolation of patients with tuberculosis were at negative pressure in relation to the corridor when tested with smoke tubes in The 1992. National Institute for September, Occupational Safety and Health (NIOSH) confirmed in August, 1990, that the ventilation system provided at least six air exchanges per hour with two outside air exchanges per hour. Air from the HIV ward was exhausted to the outside and not recirculated to another area within the hospital. No ultraviolet germicidal irradiation was used on the HIV ward. During our investigation, patients were observed to be in their rooms with doors closed unless they were being transported to medically necessary offward procedures; they wore surgical masks en route to these procedures. Healthcare workers wore the 3M 1812 mask (St Paul, Minnesota, USA)-a surgical submicron mask-from September, 1990 to March, 1992, and the 3M 1814 respiratory protection device-a dust-mist particulate respirator-from April, 1992, onwards. The only differences between the 3M 1812 and 3M 1814 are the former has never been submitted for testing to NIOSH for approval as a particulate respirator and the face straps are 1 inch (2-54 cm) longer; otherwise, filtration characteristics are identical. The change in respirators was made solely on the basis that the 3M 1814 is NIOSH approved, whereas the 3M 1812 is not. The Occupational Safety and Health Administration, the federal agency that enforces occupational health regulations in the USA, requires use of a NIOSH-approved device if a respirator is used for worker protection. Particulate respirators were readily available at the entrance to all tuberculosis isolation rooms and healthcare workers were observed to wear respirators whenever they entered tuberculosis isolation rooms. Each worker used one respirator per shift unless it was damaged or wet, in which case it was discarded before the shift was over.

Patient-to-patient MDR-TB transmission Total infectious-MDR-TB-patient-days decreased from 335 to 325 to 80 between the initial, early, and late follow-up periods (figure 1). The proportion of infectious-MDR-TB-patient-days (per total days in the period X 100) decreased from 222/100 days to 119/100 days to 16/100 days in the three periods. 26 patients met the case definition of MDR-TB (median age 35 years, range 17-55; 20 [77%] male). 2

(8%) case patients were diagnosed as having drugsusceptible tuberculosis before their first MDR-TBpositive sputum culture; 1 of these patients had had drugsusceptible tuberculosis before January, 1990. 25 (96%) case patients died and 1 was lost to follow-up after she moved

out

of the

area.

237

Figure 2: Distribution of MDR-TB patients positive MDR-TB culture

on

HIV ward

Figure 3: Distribution of healthcare workers with tuberculinskin-test conversions

by date

of first

case patients were admitted during the initial 11 and (42%) during the follow-up-period (figure period All 15 of the case patients admitted during the initial 2). had been period exposed to infectious MDR-TB patients at Jackson Memorial Hospital, 12 (80%) while on the HIV ward (8 before the study period and 4 during the initial period). The 3 remaining initial-period cases were exposed to infectious MDR-TB patients in the HIV clinic. Of the 11 case patients admitted during the followup period, 10 had been exposed to infectious MDR-TB patients at the hospital, 5 of whom were exposed on the HIV ward. All the latter 5 patients were exposed during the initial period. 4 of the 10 follow-up-period case patients with previous exposure to infectious MDR-TB patients at the hospital were exposed in the HIV clinic, and 1 had previously been admitted to a medical ward where MDR-TB patients had been treated. The remaining follow-upperiod MDR-TB patient had no history of admission to Jackson Memorial Hospital or HIV clinic visits. This patient did have a history of drug-susceptible tuberculosis. None of the MDR-TB patients on the HIV ward admitted during the follow-up-period had infection traced to exposure on the HIV ward during the follow-up

15

(58%)

period. Isolates were available from 24 of the 26 case patients; 23 isolates had one of the two RFLP patterns identified in the original investigation as the outbreak strains (21 with RFLP pattern 8132, 2 with RFLP pattern 8136).3 The patient whose MDR-TB isolate had a unique RFLP

pattern (8224), had not previously been MDR-TB patients on the HIV ward.

exposed

to

Healthcare workers 39 healthcare workers on the HIV ward met the definition of susceptibility. 25 susceptible healthcare workers were included for analysis in the initial period and 27 in the follow-up period (17 in the early and 23 in the late followup periods). There were no significant differences in age, sex, race, or occupation between workers with and without tuberculin-skin-test conversions. All 10 workers with skin-test conversions had direct patient care responsibilities. No worker had an immunocompromising disorder. To date, no worker with a newly converted skin test has developed active disease. 3 (11%) of 27 susceptible healthcare workers on the 238

HIV ward had tuberculin-skin-test conversions

during the

In

November, 1990, a known follow-up period (figure 3). MDR-TB patient was readmitted to the ward without isolation precautions because he recently had been discharged while sputum-smear-negative for AFB and on medication; 2 of the 3 workers with conversions were exposed to this patient while out of isolation. A review of the records of all MDR-TB patients revealed that at readmission this patient was sputum-smear positive for AFB. Subsequently, all MDR-TB patients were placed in isolation on readmission irrespective of sputum-smear or medication status (table). Since this additional precaution was taken in February, 1991, no skin-test conversions have occurred among HIV-ward workers. Tuberculinskin-test conversion rates among susceptible workers on the HIV ward decreased significantly from 7 of 25 (28%) in the initial period to 3 of 17 (18%) in the early followup period, and 0 of 23 in the late follow-up period (X2 for

trend, p<0-01). During the early follow-up period, the number of

infectious-MDR-TB-patient-exposure-days did not differ significantly between the 3 healthcare workers with and the 14 without skin-test conversions (median 139 vs 129 days). During the whole follow-up period, the skin-test conversion rate was higher among workers on the HIV ward than among those on the control ward (3/27 vs 0/16) but not significantly so. Discussion Whereas nosocomial transmission of tuberculosis to healthcare workers has been well-documented,’4-’-’ nosocomial acquisition of tuberculosis by patients was rarely reported until recent outbreaks of MDR-TB.I-7 These outbreaks have been characterised by morbidity and mortality among both patients and workers .2,11,11 More than 100 patients have been infected, over 80% of whom have died, and at least 16 healthcare workers have contracted MDR-TB, of whom at least 5 have died." The outbreak at Jackson Memorial Hospital of nosocomial transmission of MDR-TB from patient to patient and patient to healthcare workers provided the opportunity to evaluate the efficacy of current recommendations for terminating MDR-TB outbreaks and preventing further transmission.3 Factors associated with tuberculosis transmission at the time of the outbreak

lapses in isolation practices for patients with tuberculosis, inadequate isolation facilities, and delays in the diagnosis of active tuberculosis and recognition of drug resistance. Our follow-up investigation provides evidence that, when fully implemented, measures similar to the 1990 CDC tuberculosis guidelines effectively stopped and then prevented MDR-TB transmission to both patients and healthcare workers. Of 11 MDR-TB patients in the follow-up period, none had illness that could be traced to an exposure on the HIV ward during the follow-up period, although infectious MDR-TB patients were present on the ward. Since June, 1992, the hospital’s Office of Tuberculosis Control has not traced a single case of newly diagnosed MDR-TB to exposure on the HIV

emphasises the impact of control measures such as early identification, adequate treatment, and isolation. Follow-up of subsequent development of MDR-TB in HIV-ward patients was limited to readmission to Jackson Memorial Hospital. Patients who moved or were admitted to another hospital would have been lost to our study. However, Jackson Memorial Hospital is the main healthcare centre for HIV-infected people in Miami, and HIV-infected patients with a history of admission to the hospital would most likely be transferred there if they presented to other local institutions. Moreover, most HIV-infected patients with MDR-TB had a short incubation period from exposure to active disease, were very ill, and therefore were unlikely to have moved from

ward. The tuberculin-skin-test conversion rate among healthcare workers declined during the follow-up period. After additional measures were taken in February, 1991, to ensure that patients with MDR-TB were placed in isolation during every hospital admission, no skin-test conversions among workers had occurred up to June, 1994. Moreover, the 3 workers with skin-test conversions during the follow-up period did not have a significantly higher number of days of exposure to infectious MDRTB patients than workers without conversions. This finding suggests that the skin-test conversions were due to an isolated breach, other than an overall failure, of the infection-control programme. Indeed, 2 of the 3 workers with skin-test conversions cared for a MDR-TB patient who was not thought to be infectious and therefore was not in isolation. Although the number of healthcare workers evaluated for skin-test conversions on the HIV and control wards is small, the fact that no workers on the HIV ward have converted since February, 1991, supports strongly the efficacy of the protection programme. Since implementation of control measures was associated with a striking decline in the number of MDRTB patients, the effect of control measures in the presence of many such patients has not been rigorously tested over a long time. However, most control measures were implemented during the period of greatest density of infectious-MDR-TB-patient-days (initial period) and although the density declined subsequently, infectious patients were still present and the potential for transmission still existed. One difficulty in the evaluation of a multifaceted infection-control programme implemented over time is assessment of the contribution to outcome of each component. Basic control measures such as changes in tuberculosis isolation policy and initial antituberculosis

Frequent surveillance of healthcare workers on a highrisk ward-in this case tuberculin skin tests every 4 months for HIV-ward workers-allowed quick identification and resolution of problems in tuberculosisinfection-control policies and practices. The increased awareness of HIV-ward workers of the nosocomial MDRTB outbreak, the frequency of tuberculin skin tests and follow-up by trained personnel, and the vigilance and activity of hospital tuberculosis-control personnel make it unlikely that any healthcare worker with new skin-test conversion would be missed. Effective prevention of nosocomial transmission of tuberculosis requires healthcare personnel to (1) identify, treat, and isolate patients with active tuberculosis as early as possible to prevent the generation of infectious airborne particles (droplet nuclei); (2) reduce the number of infectious droplet nuclei in contaminated air by environmental control methods; and (3) conduct surveillance of healthcare personnel for active tuberculosis and tuberculosis infection. Experience has shown that lapses in any of the above measures results in an increased probability of nosocomial transmission.3-’ Although recent nosocomial MDR-TB outbreaks have raised concerns about the efficacy of current recommendations for preventing or stopping MDR-TB transmission in healthcare facilities, our investigation showed that implementation of the 1990 CDC guidelines produced significant reduction and subsequent cessation of MDR-TB transmission to both patients and healthcare workers.

included

chemotherapy regimens implemented hospital infection-control personnel were aware of the outbreak. Environmental changes took longer to achieve. Data from our study suggest that patient-to-patient MDR-TB transmission on the HIV ward had been greatly reduced or stopped before negative pressure was achieved in all tuberculosis isolation rooms at all times (April, 1991). Furthermore, patient-to-healthcare worker MDRwere

as

soon

as

TB transmission on the HIV ward had been reduced before introduction of the submicron surgical mask (3M 1812) in September, 1990, and stopped before the change to the dust-mist particulate respirator (3M 1814) in April, 1992. This finding does not imply that full implementation of environmental controls or respiratoryprotection devices was not important, but instead

the

area.

Timothy Cleary, director of the Jackson Memorial Hospital Microbiology Laboratory Services, for his help in this investigation.

We thank Dr

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2

Centers for Disease Control. Nosocomial transmission of multidrugresistant tuberculosis among HIV-infected persons—Florida and New York, 1988-1991. MMWR Morb Mortal Wkly Rep 1991; 40: 585-91. Beck-Sague C, Dooley SW, Hutton MD, et al. Hospital outbreak of multidrug-resistant Mycobacterium tuberculosis infections; factors in transmission to staff and HIV-infected patients. JAMA 1992; 268: 1280-86. Fischl MA, Uttamchandani RB, Daikos GL, et al. An outbreak of tuberculosis caused by multiple-drug-resistant tubercle bacilli among patients with HIV infection. Ann Intern Med 1992; 117: 177-83. Pearson ML, Jereb JA, Frieden TR, et al. Nosocomial transmission of multidrug-resistant Mycobacterium tuberculosis; a risk to patients and health care workers. Ann Intern Med 1992; 117: 191-96. Edlin BR, Tokars JI, Grieco MH, et al. An outbreak of multidrugresistant tuberculosis among hospitalized patients with acquired

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Dooley SW, Villarino ME, Lawrence M, et al. Nosocomial transmission of tuberculosis in a hospital unit for HIV-infected patients. JAMA 1992; 267: 2632-34. 8 Selwyn PA, Hartel D, Lewis VA, et al. A prospective study of the risk of tuberculosis among intravenous drug users with human immunodeficiency virus infection. N Engl J Med 1989; 320: 545-50. 9 Rudnik J, Kroc K, Manangan L, Banerjee S, Pugliese G, Jarvis W. How prepared are US hospitals to control nosocomial transmission of tuberculosis? Third Annual Meeting of the Society for Hospital Epidemiology of America; 1993 Apr 18-20; Chicago: A1 (abstr). 10 Centers for Disease Control. Guidelines for preventing the transmission of tuberculosis in health-care settings, with special focus on HIV-related issues. MMWR Morb Mortal Wkly Rep 1990; 39 (no RR-17). 11 Cave MD, Eisenbach KD, McDermott PF, Bates JH, Crawford JT. IS6110: conservation of sequence in the Mycobacterium tuberculosis complex and its utilization in DNA fingerprinting. Mol Cell Probes 1991; 5: 73-80.

7

12 Centers for Disease Control. Screening for tuberculosis and tuberculosis infection in high-risk populations and the use of preventive therapy for tuberculosis infection in the United States:

recommendations of the Advisory Committee for Elimination of Tuberculosis. MMWR Morb Mortal Wkly Rep 1990; 39 (no RR-8): 1-7. 13 American Thoracic Society. Centers for Disease Control. Diagnostic standards and classification of tuberculosis. Am Rev Respir Dis 1990; 142: 725-35. 14 Catanzaro A. Nosocomial tuberculosis. Am Rev Respir Dis 1982; 125: 559-62. 15 Ehrenkranz NJ, Kicklighter JL. Tuberculosis outbreak in a general hospital: evidence of airborne spread of infection. Ann Intern Med 1972; 77: 377-82. 16 Haley CE, McDonald RC, Rossi L, et al. Tuberculosis epidemic among hospital personnel. Infect Control Hosp Epidemiol 1989; 10: 204-10. 17 Kantor HS, Poblete R, Pusateri SL. Nosocomial transmission of tuberculosis from unsuspected disease. Am J Med 1988; 84: 833-38. 18 Hopewell PC. Impact of human immunodeficiency virus infection on the epidemiology, clinical features, management, and control of tuberculosis. Clin Infect Dis 1992; 15: 540-47. 19 Jarvis WR. Nosocomial transmission of multidrug-resistant Mycobacterium tuberculosis. Res Microbiol 1993; 144: 117-22.

Adolescent sexual involvement: time for

At the United Nations International Conference on Population and Development in Cairo last September, the most contentious subject after abortion was adolescent sexual behaviour. The health issues associated with early adolescent sexual involvement are undisputed but also under-acknowledged. As Powell and Wright noted last year1 with respect to North America, over the past decade there has been an unprecedented epidemic of sexually transmitted diseases (STDs), especially among adolescent and young adult women. The rates of chlamydial infection, gonorrhoea, herpes, and genital warts have been soaring, yet awareness of their impact on the health of infected women has not increased proportionately. Despite an educational focus on STD prevention among adolescents, teenagers remain at great risk for acquiring an STD, including human immunodeficiency virus infection.2.3 Clinicians are involved not only in treatment of sexually transmitted infections, many of which are acquired during the teenage years, but also in management of the sequelae. Examples of such complications are cancerous changes in the genital tract, infertility and ectopic pregnancies, transmission of STDs to newborn babies, chronic pain caused by scarring within the female genital tract, and death related to AIDS. What can be done to end the STD epidemic? The usual response is promotion of various medical interventions, with exhortations to develop better condoms, new female barrier methods, and vaccines against STD organisms.4 However, this focus on technological interventions to prevent the potential consequences of behaviour fails to address the fact that the increasing problems of STDs and unintended teenage pregnancy are associated with greater

2911-66 Street, Edmonton, Alberta, Canada (S J Genuis FRCSC, S K Genuis BScOT)

Correspondence to: Dr S J Genuis 240

primary prevention

sexual involvement by ever younger teenagers. Physicians and policy makers must begin to consider whether risk reduction through technological means has been emphasised at the expense of investigating and addressing primary problematic behaviour. The dilemma of unintended teenage pregnancy illustrates this concem.5 Although oral contraceptives are a very effective method of preventing pregnancy, numerous programmes aimed at reducing unintended adolescent pregnancy, increased access to oral contraceptives, and a widespread public perception that "the pill" is a reliable form of birth control have had little effect in this age group. The worldwide epidemic of chlamydial infection likewise illustrates the shortcomings of technology. Despite excellent methods of testing and effective treatment to eradicate disease and prevent further transmission, coupled with educational strategies, the World Health Organization estimates that the global incidence of chlamydia has risen to a minimum of 50 million cases per year;6 many of these infections occur in adolescents.’ For some, these facts suggest that there is a need for even more extensive education related to contraception and safer sex. However, in the USA, contraceptive-based sex education programmes have provided little evidence of reduced sexual activity, diminished teenage pregnancy rates, or increased effective contraceptive use.8 In Canada, where sexuality programmes have been established in schools for longer than in the USA and where some provinces conduct awareness campaigns, STDs and adolescent pregnancy continue to rise5.9 and the clinical evidence is that existing prevention strategies are not

working.4 In Sweden, comprehensive mandatory sex education begins in the early school years and publicly funded adolescent health clinics are well established. Even so, there have been disturbing trends of STDs and teenage pregnancy.10 Moreover, despite extensive education and