Is there a seasonal variation in gonorrhea and chlamydia in adolescents?

Vaccine value profile for Neisseria gonorrhoeae

Neisseria gonorrhoeae infection (gonorrhoea) is a global public health challenge, causing substantial sexual and reproductive health consequences, such as infertility, pregnancy complications and increased acquisition or transmission of HIV. There is an urgency to controlling gonorrhoea because of increasing antimicrobial resistance to ceftriaxone, the last remaining treatment option, and the potential for gonorrhoea to become untreatable. No licensed gonococcal vaccine is available. Mounting observational evidence suggests that N. meningitidis serogroup B outer membrane vesicle-based vaccines may induce cross-protection against N. gonorrhoeae (estimated 30%-40% effectiveness using the 4CMenB vaccine). Clinical trials to determine the efficacy of the 4CMenB vaccine against N. gonorrhoeae are underway, as are Phase 1/2 studies of a new gonococcal-specific vaccine candidate. Ultimately, a gonococcal vaccine must be accessible, affordable and equitably dispensed, given that those most affected by gonorrhoea are also those who may be most disadvantaged in our societies, and most cases are in less-resourced settings. This vaccine value profile (VVP) provides a high level, holistic assessment of the current data to inform the potential public health, economic and societal value of pipeline vaccines. This was developed by a working group of subject matter experts from academia, non-profit organizations, public private partnerships and multi-lateral organizations. All contributors have extensive expertise on various elements of the N. gonorrhoeae VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using published data obtained from peer-reviewed journals or reports.

Homo temporus: Seasonal Cycles as a Fundamental Source of Variation in Human Psychology

Many animal species exhibit seasonal changes in their physiology and behavior. Yet despite ample evidence that humans are also responsive to seasons, the impact of seasonal changes on human psychology is underappreciated relative to other sources of variation (e.g., personality, culture, development). This is unfortunate because seasonal variation has potentially profound conceptual, empirical, methodological, and practical implications. Here, we encourage a more systematic and comprehensive collective effort to document and understand the many ways in which seasons influence human psychology. We provide an illustrative summary of empirical evidence showing that seasons impact a wide range of affective, cognitive, and behavioral phenomena. We then articulate a conceptual framework that outlines a set of causal mechanisms through which seasons can influence human psychology-mechanisms that reflect seasonal changes not only in meteorological variables but also in ecological and sociocultural variables. This framework may be useful for integrating many different seasonal effects that have already been empirically documented and for generating new hypotheses about additional seasonal effects that have not yet received empirical attention. The article closes with a section that provides practical suggestions to facilitate greater appreciation for, and systematic study of, seasons as a fundamental source of variation in human psychology.

Interruption time series analysis using autoregressive integrated moving average model: evaluating the impact of COVID-19 on the epidemic trend of gonorrhea in China

BACKGROUND

Interrupted time series (ITS) analysis is a growing method for assessing intervention impacts on diseases. However, it remains unstudied how the COVID-19 outbreak impacts gonorrhea. This study aimed to evaluate the effect of COVID-19 on gonorrhea and predict gonorrhea epidemics using the ITS-autoregressive integrated moving average (ARIMA) model.

METHODS

The number of gonorrhea cases reported in China from January 2005 to September 2022 was collected. Statistical descriptions were applied to indicate the overall epidemiological characteristics of the data, and then the ITS-ARIMA was established. Additionally, we compared the forecasting abilities of ITS-ARIMA with Bayesian structural time series (BSTS), and discussed the model selection process, transfer function, check model fitting, and interpretation of results.

RESULT

During 2005-2022, the total cases of gonorrhea were 2,165,048, with an annual average incidence rate of 8.99 per 100,000 people. The highest incidence rate was 14.2 per 100,000 people in 2005 and the lowest was 6.9 per 100,000 people in 2012. The optimal model was ARIMA (0,1, (1,3)) (0,1,1)12 (Akaike's information criterion = 3293.93). When predicting the gonorrhea incidence, the mean absolute percentage error under the ARIMA (16.45%) was smaller than that under the BSTS (22.48%). The study found a 62.4% reduction in gonorrhea during the first-level response, a 46.47% reduction during the second-level response, and an increase of 3.6% during the third-level response. The final model estimated a step change of - 2171 (95% confidence interval [CI] - 3698 to - 644) cases and an impulse change of - 1359 (95% CI - 2381 to - 338) cases. Using the ITS-ARIMA to evaluate the effect of COVID-19 on gonorrhea, the gonorrhea incidence showed a temporary decline before rebounding to pre-COVID-19 levels in China.

CONCLUSION

ITS analysis is a valuable tool for gauging intervention effectiveness, providing flexibility in modelling various impacts. The ITS-ARIMA model can adeptly explain potential trends, autocorrelation, and seasonality. Gonorrhea, marked by periodicity and seasonality, exhibited a downward trend under the influence of COVID-19 intervention. The ITS-ARIMA outperformed the BSTS, offering superior predictive capabilities for the gonorrhea incidence trend in China.

Visits to Sexually Transmitted Infection Clinics in Italy from January 2016 to November 2021: A Multicenter, Retrospective Study

There is no evidence of seasonal variation in visits to clinics dedicated to sexually transmitted infections (STIs) in Italy, nor of changes after the advent of the COVID-19 pandemic. An observational, retrospective, multicentric study was conducted to record and analyze all the visits to the STI clinics of the Dermatology Units of the University Hospitals of Ferrara and Bologna and of the Infectious Disease Unit of Ferrara, Italy, between January 2016 and November 2021. Overall, 11.733 visits were registered over a 70-month study period (63.7% males, mean age 34.5 ± 12.8 yrs). The mean number of monthly visits significantly decreased from the advent of the pandemic (136) compared to before (177). In the pre-pandemic period, visits to STI clinics increased in the autumn/winter months when compared to spring/summer, while the trend was the opposite in the pandemic period. Thus, during the pandemic, both an overall significant reduction in visits to STI clinics and a reversal in their seasonality were observed. These trends affected males and females equally. The marked decrease, mostly found in the pandemic winter months, can be linked to the "lockdown"/self-isolation ordinances and social distancing measures during the colder months, coinciding with the spread of the COVID-19 infection, which limited the opportunities for meeting and socializing.

Epidemiological characteristics of gonorrhea and its influential meteorological factors: a 14-year retrospective assessment in China

This study aimed to investigate the seasonal variation of gonorrhea in China, and to analyze the relationship between the incidence of gonorrhea and meteorological factors. Data from gonorrhea cases were obtained from the Disease Prevention and Control Bureau and the Data-Center for China Public Health Science, Chinese Center for Disease Control and Prevention, and the incidence of gonorrhea in China from 1 January 2006 to 31 December 2019 was analyzed. Meteorological data from the same period were obtained from the South China Meteorological Data Sharing Center, including the average monthly temperature, relative humidity, atmospheric pressure, sunshine hours, number of rainy days, and precipitation. The ratio-to-moving average method and seasonal subseries plots were used to analyze the seasonality of gonorrhea cases. The distributed lag non-linear model and attribution risks were used to investigate the effects of meteorological indexes on gonorrhea cases. The number of gonorrhea cases showed seasonal variation, with a peak in the third quarter and a decline in the first quarter. The Spearman assay showed that the reported number of patients with gonorrhea was positively correlated with the monthly temperature, relative humidity, precipitation, and number of rainy days. The risk of gonorrhea onset was highest at 6-11 °C, and the highest risk occurred when the average monthly temperature was 7 °C (resulting in an increase of 14.5% compared with 13 °C); a similar result was found regarding the cumulative risk of gonorrhea onset in relation to temperature. The attribution score of temperature to the onset of gonorrhea was 5.02% (95% confidence interval: - 3.84%, 13.88%). The study findings suggest that increased emphasis should be placed on screening for gonorrhea during summer and autumn, and that education on safe sexual behavior should be promoted during these times.

Changing from Clinician-Collected to Self-Collected Throat Swabs for Oropharyngeal Gonorrhea and Chlamydia Screening among Men Who Have Sex with Men

The coronavirus disease 2019 (COVID-19) pandemic has led many clinics to move from clinician-collected to self-collected oropharyngeal swabs for the detection of sexually transmitted infections (STIs). Before this change, however, self-collection was used primarily for genital and anorectal infections, with only limited studies on the performance of self-collection of oropharyngeal swabs for oropharyngeal STI detection. The Melbourne Sexual Health Centre (MSHC) changed from clinician-collected to self-collected oropharyngeal swabs for oropharyngeal gonorrhea and chlamydia screening on 16 March 2020 in order to reduce health care worker risk during the COVID-19 pandemic. We compared the proportions of valid and positive samples for gonorrhea and chlamydia among men who have sex with men (MSM) in two time periods; the clinician collection period, between 20 January and 15 March 2020, and the self-collection period, between 16 March and 8 May 2020. A total of 4,097 oropharyngeal swabs were included. The proportion of oropharyngeal swabs with equivocal or invalid results for Neisseria gonorrhoeae was higher in the self-collection period (1.6% [24/1,497]) than in the clinician collection period (0.9% [23/2,600]) (P = 0.038), but the proportions did not differ for the detection of Chlamydia trachomatis The positivity rates of oropharyngeal N. gonorrhoeae (adjusted prevalence ratio [PR], 1.07 [95% confidence interval {CI}, 0.85 to 1.34]) (P = 0.583) and oropharyngeal C. trachomatis (adjusted PR, 0.84 [95% CI, 0.51 to 1.39]) (P = 0.504) specimens did not differ between the two periods. Self-collected oropharyngeal swabs for the detection of N. gonorrhoeae and C. trachomatis have acceptable performance characteristics and, importantly, reduce health care worker exposure to respiratory infections.

The association between ambient temperature and clinical visits for inflammation-related diseases in rural areas in China

BACKGROUND

The association between temperature and mortality has been widely reported. However, it remains largely unclear whether inflammation-related diseases, caused by excessive or inappropriate inflammatory reaction, may be affected by ambient temperature, particularly in low-income areas.

OBJECTIVES

To explore the association between ambient temperature and clinical visits for inflammation-related diseases in rural villages in the Ningxia Hui Autonomous Region, China, during 2012─2015.

METHODS

Daily data on inflammation-related diseases and weather conditions were collected from 258 villages in Haiyuan (161 villages) and Yanchi (97 villages) counties during 2012─2015. A Quasi-Poisson regression with distributed lag non-linear model was used to examine the association between temperature and clinical visits for inflammation-related diseases. Stratified analyses were performed by types of diseases including arthritis, gastroenteritis, and gynecological inflammations.

RESULTS

During the study period, there were 724,788 and 288,965 clinical visits for inflammation-related diseases in Haiyuan and Yanchi, respectively. Both exposure to low (RR: 2.045, 95% CI: 1.690, 2.474) and high temperatures (RR: 1.244, 95% CI: 1.107, 1.399) were associated with increased risk of total inflammation-related visits in Haiyuan county. Low temperatures were associated with increased risks of all types of inflammation-related diseases in Yanchi county (RR: 4.344, 95% CI: 2.887, 6.535), while high temperatures only affected gastroenteritis (RR: 1.274, 95% CI: 1.040, 1.561). Moderate temperatures explained approximately 26% and 33% of clinical visits due to inflammation-related diseases in Haiyuan and Yanchi, respectively, with the burden attributable to cold exposure higher than hot exposure. The reference temperature values ranged from 17 to 19 in Haiyuan, and 12 to 14 in Yanchi for all types of clinical visits.

CONCLUSIONS

Our findings add additional evidence for the adverse effect of suboptimal ambient temperature and provide useful information for public health programs targeting people living in rural villages.

Seasonal variations in kissing and sexual activities among men who have sex with men in Melbourne, Australia: implications for seasonal sexually transmissible infection preventions and interventions

Background Previous studies have shown that there is a peak in sexually transmissible infection (STI) cases and sexual activities around summer, but there has been no study examining whether kissing also follows a similar seasonal pattern. The aim of this study was to examine the seasonal patterns of kissing and sex partners among gay, bisexual and other men who have sex with men (MSM).

METHODS

A short cross-sectional study was conducted among MSM attending the Melbourne Sexual Health Centre between March 2016 and February 2017. Participants were asked to report the number of kissing-only, sex-only and kissing-with-sex male partners in the last 3 months. The mean number of male partners was calculated and stratified by Australia's seasons. The seasonal trend in the number of partners was assessed by negative binomial regression models.

RESULTS

In total, 4391 MSM were included in the analysis. The number of kissing-only and sex-only partners increased significantly from autumn to summer among MSM in Melbourne (Ptrend <0.001). MSM reported the highest number of male partners for kissing-only (mean: 4.91; 95% confidence intervals (CI): 4.78-5.04) and sex-only (mean: 1.91; 95% CI: 1.83-1.99) around summer compared with other seasons. However, the number of kissing-with-sex partners remained stable across seasons.

CONCLUSIONS

The study data suggest that there is a peak in kissing-only and sex-only partners among MSM around summer and holiday seasons.

Azithromycin Susceptibility Among Neisseria gonorrhoeae Isolates and Seasonal Macrolide Use

Rising azithromycin nonsusceptibility among Neisseria gonorrhoeae isolates threatens current treatment recommendations, but the cause of this rise is not well understood. We performed an ecological study of seasonal patterns in macrolide use and azithromycin resistance in N. gonorrhoeae, finding that population-wide macrolide use is associated with increased azithromycin nonsusceptibility. These results, indicative of bystander selection, have implications for antibiotic prescribing guidelines.

Seasonal variation in gonorrhoea incidence among men who have sex with men

Background After reviewing urethral gonorrhoea cases among men who have sex with men (MSM) at the South Australia Specialist Sexual Health (SASSH) in Adelaide, Australia, we noticed peaks of gonorrhoea among MSM occurred predominantly in the first quarter of the year (January-March). The aim of this study was to formally test this hypothesis against data from a similar period at three sexual health services, one each in Adelaide, Melbourne and Sydney.

METHODS

This study was a retrospective analysis of computerised records at the three Australian sexual health services. Potential risk factors for urethral gonorrhoea among MSM were also reviewed at the SASSH.

RESULTS

More peaks of gonorrhoea cases were observed in the first quarter of the year in Adelaide and Sydney and in the second and fourth quarter in Melbourne. Factors independently associated with urethral gonorrhoea at the SASSH were being a young MSM, especially those aged 25-29 (odds ratio (OR) 2.66, 95% confidence interval (CI): 2.00-3.54), having more than one sexual partner (OR 1.71, 95% CI: 1.43-2.04), having had sex interstate and overseas (OR 1.52, 95% CI: 1.06-2.17), and presenting in the first quarter (OR 1.30, 95% CI: 1.10-1.55).

CONCLUSION

Our data suggest that gonorrhoea among MSM occurs in a seasonal pattern, particularly late summer into early autumn. This has implications for the provision of health services over the year and for the timing of health promotion activities.

Is there an ethnic variation in the epidemiology of gonorrhoea? A retrospective population-based study from northern Israel over 15 years between 2001 and 2015

OBJECTIVE

To investigate the trends in the incidence of gonorrhoea through an extended period of time and to compare the epidemiology of gonorrhoea infection between 2 distinct ethnic groups (Jews and Arabs).

DESIGN

A retrospective population-based cohort study was conducted on all consecutive patients diagnosed with gonorrhoea through the years 2001-2015.

SETTING

National Department of Epidemiology of the Ministry of Health, Haifa District, Israel.

PARTICIPANTS

A total of 837 reports on gonorrhoea were received, derived from 779 (93.1%) male and 58 (6.9%) female patients. Approximately 1 million people reside in the Haifa region.

PRIMARY AND SECONDARY OUTCOME MEASURES

We examined the incidence rate of gonorrhoea among residents of Haifa District, northern Israel from 2001 to 2015, by reviewing archives of the Department of Epidemiology, Israeli Ministry of Health. Notified cases were stratified by age, gender and ethnicity.

RESULTS

The overall gonorrhoea incidence was 6.4 cases per 100 000 population per year. The annual incidence rate dropped from 20.5 per 100 000 population in 2001 to a period of 2.2 cases per 100 000 population in 2005, showing a >9-fold decline. This was followed by a relatively steady increase of incidence of 2.5-4.5 per 100 000 population from 2006 to 2015. Men were predominantly more affected than women, with a 13.4-fold higher incidence rate. The most affected age group was residents between 25 and 34 years old. The estimated rate among Jews was 2.5-fold higher relative to Arabs. Only 1.3% recurrent episodes of gonorrhoea were reported. The prevalence of HIV positivity among patients with gonorrhoea is significantly higher than that of the general population (500.0 vs 88.1 cases per 100 000 population, respectively, p<0.001).

CONCLUSIONS

Gonorrhoea incidence rate decreased dramatically until 2005, with no substantial subsequent fluctuations. The infection is much more prevalent among patients of Jewish ethnicity, possibly due to riskier sex practices.

Patients with Epididymo-Orchitis and Meteorological Impact in Taiwan: A Nationwide Population-Based Study

Background. Epididymo-orchitis is a common infectious disease among men, especially men aged 20 to 39 years. The aim of this study was to analyze possible associations of various meteorological indicators on the incidence of epididymo-orchitis in Taiwan. Methods and Materials. This nationwide population-based study collected data on cases of epididymo-orchitis that were newly diagnosed from 2001 to 2013 in Taiwan. Monthly meteorological indicators, including average temperatures, humidity, rainfall, total rain days, and sunshine hours, were collected from the Central Weather Bureau of Taiwan. Data for a total of 7,233 patients with epididymo-orchitis were collected for this study. Results. The monthly incidence of epididymo-orchitis was positively correlated with temperature, rainfall, and sunshine hours. The average monthly temperature had a linear correlation with the incidence of epididymo-orchitis (ß = 0.11). The monthly average temperature is significantly related, with a positive linear correlation, to the incidence of epididymo-orchitis in Taiwan. Conclusion. This finding may constitute useful information in terms of helping physicians to distinguish between patients with epididymo-orchitis and testicular torsion in hot or cold weather.

Summer heat: a cross-sectional analysis of seasonal differences in sexual behaviour and sexually transmissible diseases in Melbourne, Australia

OBJECTIVES

To date, no study has correlated seasonal differences in sexual behaviour with the seasonal differences in sexually transmitted infections (STIs); and no seasonal study of STIs has been conducted in the southern hemisphere. Our study aimed to describe seasonal differences in sexual behaviour and correlate this with seasonal differences in STI diagnoses in Melbourne, Australia.

METHOD

This was a cross-sectional study of individuals attending the Melbourne Sexual Health Centre over a 9-year period from 2006 to 2014. We conducted separate analyses for men who have sex with men (MSM) and men who have sex with women (MSW), and women. Seasonal patterns of sexual behaviour and STI positivity were examined within each group.

RESULTS

All groups reported a higher number of partners over the preceding three months for consultations in summer compared with winter (MSM mean 5.48 vs 5.03; MSW mean 2.46 vs 2.31; women mean 1.83 vs 1.72). Urethral gonorrhoea diagnoses among MSM were higher in summer compared with winter (OR 1.23, 95% CI 1.04 to 1.46). Similarly, non-gonococcal urethritis (NGU) diagnoses among MSW were the highest in summer (OR 1.11, 95% CI 1.03 to 1.20), but there was no seasonal difference in NGU diagnoses when we adjusted for partner numbers. In women, pelvic inflammatory disease (PID) diagnoses peaked in autumn, when rates were higher than in winter (OR 1.30, 95% CI 1.09 to 1.55).

CONCLUSIONS

Our results describe a peak in sexual partner number and STI diagnoses during consultations in summer in men and a rise in PID in autumn in women.

Seasonal variation in internet keyword searches: a proxy assessment of sex mating behaviors

The current study investigated seasonal variation in internet searches regarding sex and mating behaviors. Harmonic analyses were used to examine the seasonal trends of Google keyword searches during the past 5 years for topics related to pornography, prostitution, and mate-seeking. Results indicated a consistent 6-month harmonic cycle with the peaks of keyword searches related to sex and mating behaviors occurring most frequently during winter and early summer. Such results compliment past research that has found similar seasonal trends of births, sexually transmitted infections, condom sales, and abortions.

A meta-analysis of the efficacy of ocular prophylactic agents used for the prevention of gonococcal and chlamydial ophthalmia neonatorum

INTRODUCTION

Neonatal eye prophylaxis has been routine in North America for more than a century. Contextual changes justify reexamining this practice, and prompted a systematic review of the efficacy of prophylactic agents.

METHODS

We searched MEDLINE (1966-2008), EMBASE (1980-2008), CINAHL (1982-2008), and the Cochrane library (the first quarter of 2008) for relevant clinical trials and hand-searched the resulting reference lists. We independently evaluated eligibility and study quality. Meta-analyses were performed using a random effects model.

RESULTS

Each of the eight included studies had substantial methodologic weaknesses. Data to estimate the efficacy of prophylaxis in the prevention of gonococcal ophthalmia neonatorum (GON) were not available. One study found no differences in rates of chlamydial ophthalmia neonatorum (CON) when three agents were compared to no prophylaxis: silver nitrate (relative risk [RR] = 1.06; 95% confidence interval [CI], 0.55-2.02; 2225 newborns), erythromycin (RR = 0.93; 95% CI, 0.48-1.79; 2306 newborns), and tetracycline (RR = 0.82; 95% CI, 0.42-1.63; 2299 newborns). No statistically significant differences were found between agents in the prevention of GON. Erythromycin and povidone-iodine both decrease the risk of CON when compared to silver nitrate (RR = 0.71; 95% CI, 0.52-0.97; 4514 newborns, and RR = 0.52; 95% CI, 0.38-0.71; 2005 newborns, respectively).

DISCUSSION

Failure rates of universal eye prophylaxis support reexamination of this policy where the prevalence of maternal infection is low.

Secular trends of gonorrhea in young adults in Israel: three decades of follow-up

Recent reports of increased rates of gonorrhea initiated an analysis of secular trends of gonorrhea in a young adult population. Gonorrhea is a notifiable disease in the Israel Defense Forces. The diagnosis is based on the typical clinical presentation, relevant epidemiologic data, and positive bacteriological culture. For the present study, the archives of the Epidemiology Department were reviewed for all documented cases of gonorrhea from January 1, 1978 to December 31, 2008, and the annual and seasonal incidence rates were calculated. Annual gonorrhea rates decreased from 2.3 cases per 1,000 soldiers in 1978 to an all-time low of 0.07 cases per 1,000 soldiers in 2008, representing a 97% decline. Multi-year average monthly rates varied from a low of 5.83 cases per 100,000 population in February to a high of 8.97 cases per 100,000 in August. The difference in the person-time incidence (PTI) rates for winter (5.9 cases per 100,000 person-years) and summer (6.8 cases per 100,000 person-years) was statistically significant (p < 0.01). Analyzing the long-term epidemiology of gonorrhea has shown that the infection rate is continuously decreasing and that it appears to be more prevalent in the warmer months.

Summer nights

Purpose

This paper aims to examine whether greater consideration should be given to the timing of sexual health interventions within the calendar year.

Design/methodology/approach

The paper uses a review of the literature.

Findings

The evidence points to seasonality in a number of areas of sexual health among young people, including: the timing of first intercourse and conceptions, both of which peak in the summer and over Christmas; abortions which peak approximately two months later in February and late summer and sexually transmitted infections, which peak over the summer and autumn. In the case of conceptions there is evidence that the seasonal pattern among young people is different from that of adults. Potential explanations fall into four main categories: biological; behavioural; social, and service‐related.

Research limitations/implications

Many of the studies included in this review are from the USA, and some are based on either small samples or specific risk groups, which raises questions of representativeness and generalisability. Further, it is notable how little research there has been regarding seasonal variations in other aspects of sexual behaviour, such as risk reduction practice and other potential explanatory factors such as health‐seeking behaviour and availability of services.

Practical implications

The findings consistently point to periods of heightened sexual activity among young people in the summer and over Christmas, and suggest that greater consideration should indeed be given to the timing of sexual health interventions within the calendar year.

Originality/value

To the best of the authors' knowledge, no other review of this kind has yet been found.

Recent change in the annual pattern of sexually transmitted diseases in the United States

This study analyzed the 1999 to 2003 database of the Center for Disease Control and Prevention (CDC) for seasonal and longer-term time trends in the sexually transmitted diseases (STDs) of chlamydia, gonorrhea, and syphilis in the United States. Linear regression was used to ascertain time trends, and a linear mixed auto-regression model was applied to determine the statistical significance of the major peaks relative to the annualized time series mean. A statistically significant increasing trend during the 5 yr span was documented only in the incidence of chlamydia. No clear annual periodicity was detected in any of the STDs; instead, significant three-month cycles were documented in all the STDs, with prominent peaks evident in March, May, August, and November. The March and May peaks could be associated with the sexual activities of young adults during spring break, which for different colleges and universities, commences as early as mid- to late-February and concludes as late as early- to mid-April, when huge numbers of sexually active youth congregate at beach resort settings. We propose the August peak is representative of summer sexual activity, in particular, of youths during school recess when adult supervision is poor. Finally, the autumn peak seems to be an expression of an endogenous annual rhythm in human reproductive biology, exemplified by elevated levels of testosterone in young males and sexual activity at this time of the year.

Gonorrhea prevention and clinical care in the private sector: lessons learned and priorities for quality improvement

We reviewed literature on gonorrhea prevention and clinical care in the private sector, the setting where most gonorrhea cases in the United States are now diagnosed. Although most private-sector health settings had a low prevalence of gonorrhea (0.1-2.5%), some private emergency departments and specialty clinics that serve a large number of high-risk or infected patients had prevalences ranged from 1.7% to 11.0%. Studies of diverse settings and populations suggest that, in general, diagnostic testing of symptomatic patients (69-83%), appropriate treatment (61-100%), and case reporting (64-94%) are delivered more commonly than risk assessment for asymptomatic patients (15-28%), routine screening of pregnant women (31-77%), risk-reduction counseling (35-78%), and sex partner management (0-82%). To sustain the recent declines in gonorrhea incidence in the United States, private-sector providers and health systems must continue to offer gonorrhea prevention and clinical services and consider implementing interventions to improve delivery of risk assessment, risk-reduction counseling, and partner management services.

Seasonal patterns and preterm birth: a systematic review of the literature and an analysis in a London-based cohort

OBJECTIVE

The objectives of this study included a systematic review of the countries in which a seasonal pattern of preterm birth has been reported and an analysis on the seasonal variability of preterm birth in a London-based cohort.

DESIGN

Cross-sectional study.

SETTING

Eighteen maternity units in a London health region from 1988 to 2000.

POPULATION

The study population comprised 482,765, live singleton births born after 24 weeks of gestation and weighing more than 200 g.

METHODS

Systematic review and secondary analysis of seasonality over 13 years of births from the St Mary's Maternity Information System (SMMIS).

MAIN OUTCOME MEASURE

Annual patterns of preterm birth and a comparison of risk by seasons.

RESULTS

Three studies from developing countries and three from developed countries reported a seasonal pattern of preterm birth. One study from the USA reported no seasonal pattern of preterm birth. No British studies were located. Rates of preterm birth in developed countries were highest twice a year (once in winter and again in summer). In London (SMMIS data set), however, preterm births peaked only once a year, in winter. Babies born in winter were 10% more likely to be preterm compared with those born in spring (OR 1.10, 95% CI 1.07-1.14).

CONCLUSION

Establishing a seasonal pattern of birth can have important implications for the delivery of healthcare services. Most studies from both developed and developing countries support the existence of preterm birth seasonality. This study has shown that the seasonality of preterm births in this London-based cohort differs from other developed countries that have previously reported a seasonal pattern of preterm birth.

Chlamydia screening in primary care: is it useful, affordable and universal?

Genital chlamydial infection, with its possible long-term morbidity, is a serious public health problem. The number of new diagnoses is rising rapidly and, in the UK, recent evidence suggests that the infection rate in young women exceeds 10%. Screening programmes can reduce the population prevalence of infection, but uncertainty remains as to the ideal screening model. This may prove to be opportunistic screening of sexually active young women, less than 25 years of age, in primary care settings, and contact tracing of the partners of those with chlamydia. Recent literature on the practicalities of genital chlamydia screening is reviewed.