Evaluation of a phased pneumococcal conjugate vaccine introduction in Mongolia using enhanced pneumonia surveillance and community carriage surveys: a study protocol for a prospective observational study and lessons learned

Background

Streptococcus pneumoniae causes substantial morbidity and mortality among children. The introduction of pneumococcal conjugate vaccines (PCV) has the potential to dramatically reduce disease burden. As with any vaccine, it is important to evaluate PCV impact, to help guide decision-making and resource-allocation. Measuring PCV impact can be complex, particularly to measure impact on one of the most common and significant diseases caused by the pneumococcus, namely pneumonia. Here we outline the protocol developed to evaluate the impact of 13-valent PCV (PCV13) on childhood pneumonia in Mongolia, and a number of lessons learned in implementing the evaluation that may be helpful to other countries seeking to undertake pneumonia surveillance.

Methods

From 2016 PCV13 was introduced in a phased manner into the routine immunisation programme with some catch-up by the Government of Mongolia. We designed an evaluation to measure vaccine impact in children aged 2–59 months with hospitalised radiological pneumonia as a primary outcome, with secondary objectives to measure impact on clinically-defined pneumonia, nasopharyngeal carriage of S. pneumoniae among pneumonia patients and in the community, and severe respiratory infection associated with RSV and/or influenza. We enhanced an existing hospital-based pneumonia surveillance system by incorporating additional study components (nasopharyngeal swabbing using standard methods, C-reactive protein, risk factor assessment) and strengthening clinical practices, such as radiology as well as monitoring and training. We conducted cross-sectional community carriage surveys to provide data on impact on carriage among healthy children.

Discussion

Establishing a robust surveillance system is an important component of monitoring the impact of PCV within a country. The enhanced surveillance system in Mongolia will facilitate assessment of PCV13 impact on pneumonia, with radiological confirmed disease as the primary outcome. Key lessons arising from this evaluation have included the importance of establishing a core group of in-country staff to be responsible for surveillance activities and to work closely with this team; to be aware of external factors that could potentially influence disease burden estimates; to be flexible in data collection processes to respond to changing circumstances and lastly to ensure a consistent application of the pneumonia surveillance case definition throughout the study period.

Pneumococcal carriage in vaccine-eligible children and unvaccinated infants in Lao PDR two years following the introduction of the 13-valent pneumococcal conjugate vaccine

Pneumococcal carriage is a prerequisite for disease, and underpins herd protection provided by pneumococcal conjugate vaccines (PCVs). There are few data on the impact of PCVs in lower income settings, particularly in Asia. In 2013, the Lao People's Democratic Republic (Lao PDR) introduced 13-valent PCV (PCV13) as a 3 + 0 schedule (doses at 6, 10 and 14 weeks of age) with limited catch-up vaccination. We conducted two cross-sectional carriage surveys (pre- and two years post-PCV) to assess the impact of PCV13 on nasopharyngeal pneumococcal carriage in 5-8 week old infants (n = 1000) and 12-23 month old children (n = 1010). Pneumococci were detected by quantitative real-time PCR, and molecular serotyping was performed using DNA microarray. Post PCV13, there was a 23% relative reduction in PCV13-type carriage in children aged 12-23 months (adjusted prevalence ratio [aPR] 0.77 [0.61-0.96]), and no significant change in non-PCV13 serotype carriage (aPR 1.11 [0.89-1.38]). In infants too young to be vaccinated, there was no significant change in carriage of PCV13 serotypes (aPR 0.74 [0.43-1.27]) or non-PCV13 serotypes (aPR 1.29 [0.85-1.96]), although trends were suggestive of indirect effects. Over 70% of pneumococcal-positive samples contained at least one antimicrobial resistance gene, which were more common in PCV13 serotypes (p < 0.001). In 12-23 month old children, pneumococcal density of both PCV13 serotypes and non-PCV13 serotypes was higher in PCV13-vaccinated compared with undervaccinated children (p = 0.004 and p < 0.001, respectively). This study provides evidence of PCV13 impact on carriage in a population without prior PCV7 utilisation, and provides important data from a lower-middle income setting in Asia. The reductions in PCV13 serotype carriage in vaccine-eligible children are likely to result in reductions in pneumococcal transmission and disease in Lao PDR.

Introduction of inactivated poliovirus vaccine in the Philippines: Effect on health care provider and infant caregiver attitudes and practices

BACKGROUND

The introduction of inactivated poliovirus vaccine (IPV) to the Philippines' national immunization schedule meant the addition of a third injectable vaccine at a child's 14-week immunization visit. Although previous studies have shown that providing multiple vaccines at the same time affected neither the risk of severe adverse events nor vaccine efficacy, concerns were raised that providing three injections at a single visit, with two injections in one leg, might be unacceptable to health care providers (HCP) and infant caregivers.

METHODS

We conducted pre- and post-IPV introduction surveys on the acceptance and acceptability of the additional injectable vaccine in three of the Philippines' 17 administrative regions. Regions 3 and 6 were included in the pre-introduction phase and Regions 3, 6 and 10 were included in the post-introduction phase. Thirty public health centers (PHCs) were randomly sampled from each region. HCPs and infant caregivers were interviewed. In addition, vaccination records from a minimum of 20 eligible children pre-introduction and 10 children post-introduction per PHC were reviewed.

RESULTS AND DISCUSSION

We interviewed 89 HCPs and 286 infant caregivers during the pre-introduction phase and 137 HCPs and 455 caregivers during the post-introduction phase. Among 986 vaccination records reviewed post-introduction, 84% (n = 826) of children received all three recommended injections at one visit, with a range from 61% (209/342) in Region 10 to 100% (328/328) in Region 3. The proportion of HCPs reporting that they had administered three or more injectable vaccines and the proportion of caregivers that would be comfortable with their child receiving three or more injectable vaccines at one visit increased from pre- to post-introduction (p < 0.0001 for both). Eighty-seven percent of HCPs that had administered three or more injectable vaccines post-introduction reported being comfortable or very comfortable with the number of vaccines they had administered.

Epidemiology of Japanese encephalitis in the Philippines: a systematic review

Background

Japanese encephalitis virus (JEV) is an important cause of encephalitis in most of Asia, with high case fatality rates and often significant neurologic sequelae among survivors. The epidemiology of JE in the Philippines is not well defined. To support consideration of JE vaccine for introduction into the national schedule in the Philippines, we conducted a systematic literature review and summarized JE surveillance data from 2011 to 2014.

Methods

We conducted searches on Japanese encephalitis and the Philippines in four databases and one library. Data from acute encephalitis syndrome (AES) and JE surveillance and from the national reference laboratory from January 2011 to March 2014 were tabulated and mapped.

Results

We identified 29 published reports and presentations on JE in the Philippines, including 5 serologic surveys, 18 reports of clinical cases, and 8 animal studies (including two with both clinical cases and animal data). The 18 clinical studies reported 257 cases of laboratory-confirmed JE from 1972 to 2013. JE virus (JEV) was the causative agent in 7% to 18% of cases of clinical meningitis and encephalitis combined, and 16% to 40% of clinical encephalitis cases. JE predominantly affected children under 15 years of age and 6% to 7% of cases resulted in death. Surveillance data from January 2011 to March 2014 identified 73 (15%) laboratory-confirmed JE cases out of 497 cases tested.

Summary

This comprehensive review demonstrates the endemicity and extensive geographic range of JE in the Philippines, and supports the use of JE vaccine in the country. Continued and improved surveillance with laboratory confirmation is needed to systematically quantify the burden of JE, to provide information that can guide prioritization of high risk areas in the country and determination of appropriate age and schedule of vaccine introduction, and to measure the impact of preventive measures including immunization against this important public health threat.

Japanese encephalitis virus (JEV) is an important cause of neurologic infections in Asia, resulting in substantial disability and deaths. Although believed to be endemic in the Philippines, little is known of the epidemiology and geographic distribution of this disease in the country. We reviewed data from clinical studies, prevalence surveys and animal studies since the 1950s. Based on this review, JEV is an important cause of encephalitis and febrile illness in all three major island groups of the country. The majority of cases were seen in children younger than 15 years and males were more often affected than females. The national laboratory initiated testing of referred cases in 2009 and surveillance for acute encephalitis syndrome (AES) with laboratory confirmation of a subset of cases was established in 2011. From 2011 to 2014, there were 1,032 cases of suspected JE. Of 497 cases with specimens tested, 73 (15%) had laboratory-confirmed JE. Our findings confirm that JE has an extensive geographic distribution in the Philippines. These findings support the introduction of JE vaccine into the country’s routine immunization program.

Typhoid Fever surveillance and vaccine use - South-East Asia and Western Pacific regions, 2009-2013

Typhoid fever is a serious, systemic infection resulting in nearly 22 million cases and 216,500 deaths annually, primarily in Asia. Safe water, adequate sanitation, appropriate personal and food hygiene, and vaccination are the most effective strategies for prevention and control. In 2008, the World Health Organization (WHO) recommended use of available typhoid vaccines to control endemic disease and outbreaks and strengthening of typhoid surveillance to improve disease estimates and identify high-risk populations (e.g., persons without access to potable water and adequate sanitation). This report summarizes the status of typhoid surveillance and vaccination programs in the WHO South-East Asia (SEAR) and Western Pacific regions (WPR) during 2009-2013, after the revised WHO recommendations. Data were obtained from the WHO/United Nations Children's Fund (UNICEF) Joint Reporting Form on Immunization, a supplemental survey of surveillance and immunization program managers, and published literature. During 2009-2013, 23 (48%) of 48 countries and areas of SEAR (11) and WPR (37) collected surveillance or notifiable disease data on typhoid cases, with most surveillance activities established before 2008. Nine (19%) countries reported implementation of typhoid vaccination programs or recommended vaccine use during 2009-2013. Despite the high incidence, typhoid surveillance is weak in these two regions, and vaccination efforts have been limited. Further progress toward typhoid fever prevention and control in SEAR and WPR will require country commitment and international support for enhanced surveillance, targeted use of existing vaccines and availability of newer vaccines integrated within routine immunization programs, and integration of vaccination with safe water, sanitation, and hygiene measures.

Japanese encephalitis surveillance and immunization--Asia and the Western Pacific, 2012

Japanese encephalitis (JE) virus is a leading cause of encephalitis in Asia, causing an estimated 67,900 JE cases annually. To control JE, the World Health Organization (WHO) recommends that JE vaccine be incorporated into immunization programs in all areas where JE is a public health problem. For many decades, progress mainly occurred in a small number of high-income Asian countries. Recently, prospects for control have improved with better disease burden awareness as a result of increased JE surveillance and wider availability of safe, effective vaccines. This report summarizes the status of JE surveillance and immunization programs in 2012 in Asia and the Western Pacific. Data were obtained from the WHO/United Nations Children's Fund (UNICEF) Joint Reporting Form (JRF), published literature, meeting reports, and websites. In 2012, 18 (75%) of the 24 countries with areas of JE virus transmission risk conducted at least some JE surveillance, and 11 (46%) had a JE immunization program. Further progress toward JE control requires increased awareness of disease burden at the national and regional levels, availability of WHO-prequalified pediatric JE vaccines, and international support for surveillance and vaccine introduction in countries with limited resources.

Unexpectedly high HIV prevalence among female sex workers in Bangkok, Thailand in a respondent-driven sampling survey

The pattern of sex work in Thailand has shifted substantially over the last two decades from direct commercial establishments to indirect venues and non-venue-based settings. This respondent-driven sampling survey was conducted in Bangkok in 2007 among female sex workers (FSW) in non-venue-based settings to pilot a new approach to surveillance among this hidden population. Fifteen initial participants recruited 707 consenting participants who completed a behavioural questionnaire, and provided oral fluid for HIV testing, and urine for sexually transmitted infection (STI) testing. Overall HIV prevalence was 20.2% (95% confidence interval [CI] 16.3-24.7). Three-quarters of women were street-based (75.8%, 95% CI 69.9-81.1) who had an especially high HIV prevalence (22.7%, 95% CI 18.2-28.4); about 10 times higher than that found in routine sentinel surveillance among venue-based FSW (2.5%). STI prevalence (Chlamydia trachomatis and Neisseria gonorrhoeae) was 8.7% (95% CI 6.4-10.8) and 1.0% (95% CI 0.2-1.9), respectively. Lower price per sex act and a current STI infection were independently associated with HIV infection (P < 0.05). High HIV prevalence found among FSW participating in the survey, particularly non-venue-based FSW, identifies need for further prevention efforts. In addition, it identifies a higher-risk segment of FSW not reached through routine sentinel surveillance but accessible through this survey method.

HIVQUAL-T: monitoring and improving HIV clinical care in Thailand, 2002-08

OBJECTIVE

We report experience of HIVQUAL-T implementation in Thailand.

DESIGN

Program evaluation.

SETTING

Twelve government hospital clinics.

PARTICIPANTS

People living with HIV/AIDS (PLHAs) aged ≥15 years with two or more visits to the hospitals during 2002-08.

INTERVENTION

HIVQUAL-T is a process for HIV care performance measurement (PM) and quality improvement (QI). The program includes PM using a sample of eligible cases and establishment of a locally led QI infrastructure and process. PM indicators are based on Thai national HIV care guidelines. QI projects address needs identified through PM; regional workshops facilitate peer learning. Annual benchmarking with repeat measurement is used to monitor progress.

MAIN OUTCOME MEASURE

Percentages of eligible cases receiving various HIV services.

RESULTS

Across 12 participating hospitals, HIV care caseloads were 4855 in 2002 and 13 887 in 2008. On average, 10-15% of cases were included in the PM sample. Percentages of eligible cases receiving CD4 testing in 2002 and 2008, respectively, were 24 and 99% (P< 0.001); for ARV treatment, 100 and 90% (P= 0.74); for Pneumocystis jiroveci pneumonia prophylaxis, 94 and 93% (P= 0.95); for Papanicolau smear, 0 and 67% (P< 0.001); for syphilis screening, 0 and 94% (P< 0.001); and for tuberculosis screening, 24 and 99% (P< 0.01). PM results contributed to local QI projects and national policy changes.

CONCLUSIONS

Hospitals participating in HIVQUAL-T significantly increased their performance in several fundamental areas of HIV care linked to health outcomes for PLHA. This model of PM-QI has improved clinical care and implementation of HIV guidelines in hospital-based clinics in Thailand.

Access to HIV testing for sex workers in Bangkok, Thailand: a high prevalence of HIV among street-based sex workers

We offered voluntary counseling and testing (VCT) for HIV and syphilis to women attending three public sexually transmitted infection (STI) clinics in Bangkok, Thailand from May 2004 to June 2006. The testing was performed at either one of three STI clinics in Bangkok or at mobile VCT in the same area as the outreach activity. Six-hundred eighty-four women were tested. The HIV prevalences among the street-based sex workers, brothel-based sex workers and other women in these areas not reporting sex work who tested in the clinics were 45.8% (38/83), 4.2% (10/236) and 9.9% (28/284), respectively. The prevalences of syphilis in these groups were 13.3%, 2.1%, and 2.6%, respectively. Street-based sex work and longer duration of sex work were independent risk factors for HIV in-fection (p < 0.001 and p = 0.02, respectively). HIV and syphilis prevalences were 21.0% and 3.7% among 81 street-based sex workers accepting mobile VCT, The street-based sex workers in Bangkok had substantially higher HIV and syphilis prevalences than other sex workers. Street-based sex workers should be sampled during routine surveillance to obtain systematic information on disease preva-lence and risk behaviors in this group.

Indicators for sexual HIV transmission risk among people in Thailand attending HIV care: the importance of positive prevention

BACKGROUND

Almost half of all new HIV infections in Thailand occur among low-risk partners of people infected with HIV, so it is important to include people infected with HIV in prevention efforts.

METHODS

Risk for HIV transmission was assessed among people with HIV attending routine care at the National Infectious Disease Institute in Thailand. Sexual risk behaviour, sexually transmitted infection (STI-syphilis, gonorrhoea, chlamydia, trichomoniasis and genital ulcers) prevalence and HIV disclosure status were assessed. Patients were provided with STI care, risk-reduction and HIV disclosure counselling.

RESULTS

Baseline data were assessed among 894 consecutive people with HIV (395 men and 499 women) from July 2005 to September 2006. Unprotected last sex with a partner of unknown or negative HIV status (unsafe sex) was common (33.2%) and more likely with casual, commercial or male-to-male sex partners than with steady heterosexual partners (p = 0.03). People receiving antiretroviral treatment were less likely to report unsafe sex (p<0.001). Overall, 10.7% of men and 7.2% of women had a STI (p = 0.08). More women than men had disclosed HIV status to their steady partners (82.5% vs 65.9%; p = 0.05).

CONCLUSION

Indicators for HIV transmission risk were common among people attending HIV care in Bangkok. Efforts need to be strengthened to reduce unsafe casual and commercial sex and to increase HIV disclosure from men to their partners. A strategy for STI screening and treatment for people with HIV in Thailand should be developed.

The behaviour of linear alkyl benzene sulphonate under direct discharge conditions in Vientiane, Lao PDR

Direct discharge of untreated sewage to surface waters is a common practice in many parts of the world. However, relatively little is known about the behaviour of synthetic organic pollutants under these conditions. This paper describes a sampling campaign designed to track changes in water quality in a surface water system in Vientiane (Lao PDR) receiving significant quantities of untreated waste water. The study was based on following in-channel transport using a fluorescent tracer injected as a pulse, with a focus on the anionic surfactant linear alkylbenzene sulphonate (LAS) and ammonia. Water samples were collected at a number of stations with sampling times estimated to coincide with solute time-of-travel. The reduction in LAS concentration with flow-time could be approximated by first-order kinetics with a half life of about 7 h. Free ammonia concentrations decreased more slowly than LAS and remained above the level believed to be toxic for sensitive aquatic species along the entire channel. Changes in the ratios of LAS alkyl chain homologues to total LAS concentrations suggest a preferential removal of longer chain lengths. The role of biodegradation in the removal of LAS was confirmed by the presence of LAS metabolites (sulphophenylcarboxylates, SPCs) which increased systematically (as a fraction of LAS remaining) with flow-time.

A new generic approach for estimating the concentrations of down-the-drain chemicals at catchment and national scale

A new generic approach for estimating chemical concentrations in rivers at catchment and national scales is presented. Domestic chemical loads in waste water are estimated using gridded population data. River flows are estimated by combining predicted runoff with topographically derived flow direction. Regional scale exposure is characterised by two summary statistics: PEC(works), the average concentration immediately downstream of emission points, and, PEC(area), the catchment-average chemical concentration. The method was applied to boron at national (England and Wales) and catchment (Aire-Calder) scales. Predicted concentrations were within 50% of measured mean values in the Aire-Calder catchment and in agreement with results from the GREAT-ER model. The concentration grids generated provide a picture of the spatial distribution of expected chemical concentrations at various scales, and can be used to identify areas of potentially high risk.

Barriers to asymptomatic screening and other STD services for adolescents and young adults: focus group discussions

Background

Sexually transmitted diseases (STDs) are a major public health problem among young people and can lead to the spread of HIV. Previous studies have primarily addressed barriers to STD care for symptomatic patients. The purpose of our study was to identify perceptions about existing barriers to and ideal services for STDs, especially asymptomatic screening, among young people in a southeastern community.

Methods

Eight focus group discussions including 53 White, African American, and Latino youth (age 14–24) were conducted.

Results

Perceived barriers to care included lack of knowledge of STDs and available services, cost, shame associated with seeking services, long clinic waiting times, discrimination, and urethral specimen collection methods. Perceived features of ideal STD services included locations close to familiar places, extended hours, and urine-based screening. Television was perceived as the most effective route of disseminating STD information.

Conclusions

Further research is warranted to evaluate improving convenience, efficiency, and privacy of existing services; adding urine-based screening and new services closer to neighborhoods; and using mass media to disseminate STD information as strategies to increase STD screening.

Measured variation in boron loads reaching European sewage treatment works

Per capita boron loads reaching 48 sewage treatment works (STWs) in The Netherlands, Germany, Italy, and the UK have been determined from monitoring data. These have been compared with the per capita input predicted from boron in detergents, as determined from detergent product sales data. The resulting distribution of the ratios of measured boron to boron predicted from consumer usage has a 90th percentile of less than 1.5. Boron has previously been shown to be a good marker for substances contained in detergent products, as it cannot be biodegraded and is not substantially adsorbed in the sewer, and there is little or no removal during sewage treatment processes. The monitoring information on the distribution of boron loads found at the different STWs should thus be indicative of the distribution of other substances released to the environment by detergent products, as specified by the relevant industrial category (IC 5-personal/domestic) in the Technical Guidance Documents. Variation in detergent product consumption figures from 18 European countries is also low, with the country with the highest per capita detergent consumption having only 1.3 times the European average detergent use. Thus the present practice of determining a "reasonable worst case" by multiplying the average per capita consumption by a factor of four to account for geographic differences in distribution, is considered to be inappropriate. This should be replaced by a factor of less than two, which combines within country and between country variations to provide a reasonable worst case approximation of the load reaching the sewage treatment facility.

Effects of clopidogrel in addition to aspirin in patients with acute coronary syndromes without ST-segment elevation

BACKGROUND

Despite current treatments, patients who have acute coronary syndromes without ST-segment elevation have high rates of major vascular events. We evaluated the efficacy and safety of the antiplatelet agent clopidogrel when given with aspirin in such patients.

METHODS

We randomly assigned 12,562 patients who had presented within 24 hours after the onset of symptoms to receive clopidogrel (300 mg immediately, followed by 75 mg once daily) (6259 patients) or placebo (6303 patients) in addition to aspirin for 3 to 12 months.

RESULTS

The first primary outcome--a composite of death from cardiovascular causes, nonfatal myocardial infarction, or stroke--occurred in 9.3 percent of the patients in the clopidogrel group and 11.4 percent of the patients in the placebo group (relative risk with clopidogrel as compared with placebo, 0.80; 95 percent confidence interval, 0.72 to 0.90; P<0.001). The second primary outcome--the first primary outcome or refractory ischemia--occurred in 16.5 percent of the patients in the clopidogrel group and 18.8 percent of the patients in the placebo group (relative risk, 0.86; 95 percent confidence interval, 0.79 to 0.94; P<0.001). The percentages of patients with in-hospital refractory or severe ischemia, heart failure, and revascularization procedures were also significantly lower with clopidogrel. There were significantly more patients with major bleeding in the clopidogrel group than in the placebo group (3.7 percent vs. 2.7 percent; relative risk, 1.38; P=0.001), but there were not significantly more patients with episodes of life-threatening bleeding (2.2 percent [corrected] vs. 1.8 percent; P=0.13) or hemorrhagic strokes (0.1 percent vs. 0.1 percent).

CONCLUSIONS

The antiplatelet agent clopidogrel has beneficial effects in patients with acute coronary syndromes without ST-segment elevation. However, the risk of major bleeding is increased among patients treated with clopidogrel.

Gonorrhea in the HIV era: a reversal in trends among men who have sex with men

OBJECTIVES

Gonorrhea cases among men who have sex with men (MSM) declined in the early years of the HIV epidemic. We evaluated more recent trends in gonorrhea among MSM through the Centers for Disease Control and Prevention's Gonococcal Isolate Surveillance Project.

METHODS

Isolates and case information were collected from 29 US sexually transmitted disease (STD) clinics. Gonococcal urethritis cases among MSM were compared with those among heterosexual men, and cases among MSM in 1995 to 1999 were compared with earlier MSM cases.

RESULTS

Of 34,942 cases, the proportion represented by MSM increased from 4.5% in 1992 to 13.2% in 1999 (P < .001). Compared with heterosexuals, MSM were older, more often White, and more often had had gonorrhea previously, although fewer had had gonorrhea in the past year. MSM with gonorrhea in 1995 to 1999 were slightly older than those with gonorrhea in 1992 to 1994, and a higher proportion had had gonorrhea in the past year.

CONCLUSIONS

MSM account for an increasing proportion of gonococcal urethritis cases in STD clinics. Given recent evidence that gonorrhea may facilitate HIV transmission, these trends demand increased attention to safe sexual behaviors and reducing STDs among MSM.

Clinical utility of measuring white blood cells on vaginal wet mount and endocervical gram stain for the prediction of chlamydial and gonococcal infections

BACKGROUND

White blood cells on endocervical Gram stain and vaginal wet mount are frequently used to predict chlamydial and gonococcal infections. Previous studies provide conflicting evidence for the clinical utility of these tests.

GOAL

To evaluate the clinical utility of measuring white blood cells on vaginal wet mount and endocervical Gram stain for the prediction of chlamydial infection and gonorrhea.

STUDY DESIGN

Women undergoing pelvic examinations at 10 county health department family planning and sexually transmitted disease clinics were tested for chlamydial infection by ligase chain reaction assay (n = 4550) and for gonorrhea by culture (n = 4402). Vaginal wet mount and endocervical Gram stains were performed in county laboratories at the time of examination.

RESULTS

The prevalences of chlamydial infection and gonorrhea were 8.8% and 3.2%, respectively. For detection of chlamydial or gonococcal infection, the likelihood ratio was 2.85 (95% CI, 2.10-3.87) for > 30 white blood cells on vaginal wet mount and 2.91 (95% CI, 2.07-4.09) for > 30 white blood cells on endocervical Gram stain. Similar results were seen for individual diagnoses either of chlamydial infection or of gonorrhea.

CONCLUSION

Vaginal wet mount and endocervical Gram stain white blood cells are useful for the presumptive diagnosis of chlamydial infection or gonorrhea only in settings with a relatively high prevalence of infection or when other predictors can increase the likelihood of infection.

The use of measured boron concentration data from the GREAT-ER UK validation study (1996-1998) to generate predicted regional boron concentrations

The concentrations of boron in the Aire and Calder which have been measured in order to validate the GREAT-ER model have been used to derive a predicted environmental concentration (PEC) for boron in the Aire catchment in Yorkshire. The data have been obtained from 33 sites, with monthly sampling over a 2-year period. The 90th percentile of the means of measured concentrations (242 microg l(-1)) is higher than the 90th percentile predicted by the GREAT-ER model (186 microg l(-1)), if river stretches are normalised by their flow volumes, and unpolluted headwaters are included in the catchment averaging procedure. However, if the river stretches are normalised by the length of the respective stretch, and unpolluted headwaters are included, a lower regional PEC of 28 microg l(-1) is obtained. If normalisation by stretch length is appropriate for regional risk assessment, then the 90th percentile of the means of the measured data will overpredict the regional boron concentration in a catchment such as the Aire, with a low natural level of boron in the headwaters. Monitoring data for boron in the effluents from sewage treatment works in the Aire catchment, and for boron in the Went and Rother catchments, with a higher background boron level, are also given.

Longitudinal evaluation of serovar-specific immunity to Neisseria gonorrhoeae

The serovars of Neisseria gonorrhoeae that are predominant in a community change over time, a phenomenon that may be due to the development of immunity to repeat infection with the same serovar. This study evaluated the epidemiologic evidence for serovar-specific immunity to N. gonorrhoeae. During a 17-month period in 1992-1994, all clients of a sexually transmitted disease clinic in rural North Carolina underwent genital culture for N. gonorrhoeae. Gonococcal isolates were serotyped according to standard methods. Odds ratios for repeat infection with the same serovar versus any different serovar were calculated on the basis of the distribution of serovars in the community at the time of reinfection. Of 2,838 patients, 608 (21.4%; 427 males and 181 females) were found to be infected with N. gonorrhoeae at the initial visit. Ninety patients (14.8% of the 608) had a total of 112 repeat gonococcal infections. Repeat infection with the same serovar occurred slightly more often than would be expected based on the serovars prevalent in the community at the time of reinfection, though the result was marginally nonsignificant (odds ratio = 1.5, 95% confidence interval 1.0-2.4; p = 0.05). Choosing partners within a sexual network may increase the likelihood of repeat exposure to the same serovar of N. gonorrhoeae. Gonococcal infection did not induce evident immunity to reinfection with the same serovar.

Antimicrobial resistance in Neisseria gonorrhoeae

Despite a declining incidence of gonorrhea in much of the industrialized world, antimicrobial resistance continues to present a challenge to the treatment of gonococcal infections. Although no clinically significant resistance to the broad-spectrum cephalosporins has been identified, fluoroquinolone-resistant gonococcal strains are now prevalent in Australia and much of the Far East. Ongoing surveillance for antimicrobial resistance is crucial to obtain the information needed to choose effective empiric therapies for gonorrhea.

Gonorrhea in the United States, 1981-1996. Demographic and geographic trends

OBJECTIVE

To describe demographic and geographic trends in gonorrhea incidence in the United States from 1981 through 1996.

STUDY DESIGN

We analyzed aggregate gonorrhea cases reported to the Centers for Disease Control and Prevention by the 50 states, District of Columbia, and 63 large cities. Annual incidence rates (cases/100,000 persons) were calculated.

RESULTS

Between 1981 and 1996, the incidence of reported gonorrhea decreased 71.3%, from 431.5 to 124.0 cases/100,000. However, rates among blacks were 35 times higher than rates among whites in 1996 (684.6 versus 19.4) compared with 11 times higher in 1981 (1,894.3 versus 164.3). Among women of all races, 15 to 19 year olds had the highest rates (716.6 in 1996), whereas among men, 20 to 24 year olds had the highest rates (512.9 in 1996). Southern states had higher rates than other regions.

CONCLUSIONS

Large segments of the population, including adolescents, young adults, and blacks, continue to have high rates of gonococcal infection; prevention programs and health care providers should address the needs of these groups.

Antimicrobial resistance in Neisseria gonorrhoeae in the United States, 1988-1994: the emergence of decreased susceptibility to the fluoroquinolones

Antimicrobial susceptibilities of Neisseria gonorrhoeae have been prospectively determined in the Gonococcal Isolate Surveillance Project of the Centers for Disease Control and Prevention. From 1988 through 1994, susceptibilities were determined for 35,263 isolates from 27 clinics. Patients were demographically similar to those in nationally reported gonorrhea cases. In 1994, 30.5% of isolates had chromosomally or plasmid-mediated resistance to penicillin or tetracycline. Penicillin resistance increased from 1988 (8.4%) to 1991 (19.5%) and then decreased in 1994 (15.6%). Tetracycline resistance decreased from 1988 (23.4%) to 1989 (17.3%) and then increased in 1994 (21.7%). Most isolates (99.9%) were highly susceptible to broad-spectrum cephalosporins. Isolates with decreased susceptibility to ciprofloxacin increased from 1991 (0.4%) to 1994 (1.3%); 4 isolates were ciprofloxacin-resistant. Ciprofloxacin-resistant strains may not respond to therapy with recommended doses of fluoroquinolones, and the clinical importance of strains with decreased susceptibility is unknown. The emergence of fluoroquinolone resistance in N. gonorrhoeae in the United States threatens the future utility of this class of antimicrobials for gonorrhea therapy.

Fluoroquinolone resistance in Neisseria gonorrhoeae

Fluoroquinolones and broad-spectrum cephalosporins are the most effective antimicrobial agents for the treatment of gonorrhea. However, clinically significant resistance to fluoroquinolones has emerged in Neisseria gonorrhoeae. Fluoroquinolone-resistant strains account for approximately 10% of all gonococcal strains in Hong Kong and the Republic of the Philippines. As many as 50% of strains from some Far Eastern countries exhibit decreased susceptibility (intermediate resistance) to fluoroquinolones. Strains with intermediate resistance and clinically significant resistance are being isolated sporadically in North America, where resistant strains have been associated with an outbreak and with failure of infections to respond to treatment with doses of ciprofloxacin and ofloxacin recommended by the Centers for Disease Control and Prevention; strains exhibiting decreased susceptibility to these agents are endemic in at least one metropolitan area. Monitoring for fluoroquinolone resistance is now critical for ensuring adequate treatment of infections with resistant strains and for maximizing the time during which fluoroquinolones may be used to treat gonorrhea.

Vaginal discharge. How to pinpoint the cause

Vaginal discharge is a common symptom of genital infection in women. Identifying its source can be challenging, because a large number of pathogens cause vaginal and cervical infection, and several infections may coexist. Patient history and physical examination findings may suggest a diagnosis. Useful tests for etiologic diagnosis include pH analysis of vaginal fluid, the "whiff" test, wet mount examination, culture, and Gram's stain. Once the source of infection has been identified, the patient can be treated, usually with oral antibiotics, oral antifungals, or topical vaginal preparations.

Vaginal discharge

Preview A variety of genital pathogens, many of which are sexually transmitted, cause infections of the vagina and cervix. Discharge is often a prominent and telling symptom. Which infectious agents should be suspected when the discharge is accompanied by itching? Vulvar pain? Odor? Which laboratory tests are most helpful in making a diagnosis? The authors answer these and other questions in this overview of genital infections in women.