Roberto Vivancos

Foreign travel, casual sex, and sexually transmitted infections: systematic review and meta-analysis

OBJECTIVES With increasing international travel it is important to understand how frequent casual travel sex and unprotected intercourse are, and what impact this may have on the risk of acquiring sexually transmitted infections (STIs). METHODS We conducted a systematic review, and where appropriate meta-analyses, to ascertain the influence of foreign travel on behavior, including new partnerships, unprotected intercourse, and STI acquisition. RESULTS The pooled prevalence of travel-associated casual sex was 20.4% (95% confidence interval (CI) 14.8-26.7%), with 49.4% (95% CI 38.4-60.5%) of these having unprotected intercourse. The predominant characteristics of people who had new sexual partners abroad were: young age, male gender, single status, and traveling alone or with friends, with a previous history of multiple sexual partners or an STI. People who travel or stay abroad for longer periods and men who have sex with men are at higher risk of developing new sexual partnerships and having unprotected intercourse. The risk of developing an STI is increased up to 3-fold in people who experience casual travel sex. CONCLUSIONS New sexual partnerships and unprotected intercourse abroad are relatively common. People who develop new sexual partnerships and have unprotected intercourse abroad have an increase risk of STIs. There is, however, a paucity of information related to strategies to prevent the risk of STI acquisition during foreign travel.

Food-related norovirus outbreak among people attending two barbeques: epidemiological, virological, and environmental investigation.

BACKGROUND Norovirus (NoV) is commonly associated with gastrointestinal infection. It is normally transmitted person-to-person or from contaminated surfaces, although food-borne transmission is possible. METHODS We conducted environmental, epidemiological, and microbiological investigations to ascertain the route of transmission of two linked outbreaks of NoV associated with events where food was consumed. Multivariate logistic regression was used to determine food items independently associated with infection. RESULTS In outbreak A, 19 of the 26 people who completed the food questionnaire fulfilled the case definition. The highest relative risks (RR) were for chicken kebab (RR 3, 95% confidence interval (CI) 0.9-10.4), pork sausages (RR 2.1, 95% CI 0.5-9.1), pasta salad (RR 1.94, 95% CI 0.9-4.1), cheese (RR 1.6, 95% CI 0.9-2.8), and green leaf salad (RR 1.5, 95% CI 0.9-2.4). In outbreak B, 60 of the 106 people surveyed fulfilled the case definition. Green leaf salad (adjusted odds ratio (aOR) 3.2, 95% CI 1.4-9.9) and coleslaw (aOR 8.2, 95% CI 3-22.2) were independently associated with illness in the multivariate logistic regression model. NoV genogroup II genotype 6 (GII-6) was identified in cases of both outbreaks and a food handler who had prepared salads for both events. CONCLUSION Because outbreak investigations of small cohorts may not yield epidemiological association to food, most of these outbreaks may be attributed to the person-to-person transmission route. Therefore ascertainment of food-borne NoV infection may be low, underestimating the true prevalence of this route of transmission.

Effectiveness of common household cleaning agents in reducing the viability of human influenza A/H1N1

Background In the event of an influenza pandemic, the majority of people infected will be nursed at home. It is therefore important to determine simple methods for limiting the spread of the virus within the home. The purpose of this work was to test a representative range of common household cleaning agents for their effectiveness at killing or reducing the viability of influenza A virus. Methodology/Principal Findings Plaque assays provided a robust and reproducible method for determining virus viability after disinfection, while a National Standard influenza virus RT-PCR assay (VSOP 25, www.hpa-standardmethods.org.uk) was adapted to detect viral genome, and a British Standard (BS:EN 14476:2005) was modified to determine virus killing. Conclusions/Significance Active ingredients in a number of the cleaning agents, wipes, and tissues tested were able to rapidly render influenza virus nonviable, as determined by plaque assay. Commercially available wipes with a claimed antiviral or antibacterial effect killed or reduced virus infectivity, while nonmicrobiocidal wipes and those containing only low concentrations (<5%) of surfactants showed lower anti-influenza activity. Importantly, however, our findings indicate that it is possible to use common, low-technology agents such as 1% bleach, 10% malt vinegar, or 0.01% washing-up liquid to rapidly and completely inactivate influenza virus. Thus, in the context of the ongoing pandemic, and especially in low-resource settings, the public does not need to source specialized cleaning products, but can rapidly disinfect potentially contaminated surfaces with agents readily available in most homes.

School-based sex education is associated with reduced risky sexual behaviour and sexually transmitted infections in young adults

OBJECTIVE To quantify the effectiveness of school-based sexual education on risky sexual behaviour and sexually transmitted infection (STI) acquisition in adulthood. STUDY DESIGN Online survey of sexual attitudes and behaviours. METHODS Students at a British university were surveyed regarding where they learnt most about sex at 14 years of age, how easy they found talking about sexual issues with their parents and age at first intercourse. The effects of these factors were modelled on risk of recent unprotected intercourse and self-reported STIs in adulthood. RESULTS Seventy-eight of 711 (11%) students reported unprotected intercourse in the 4 weeks before the survey, and 44 (6.2%) students had ever been diagnosed with an STI. Both age at first intercourse (risk reduced by 11% per year of delayed intercourse, 95% confidence interval (CI) 3-19%) and learning about sex from lessons at school (66% reduction in risk compared with learning from ones mother, 95% CI 5-88%) were associated with reductions in risk of unprotected intercourse. Factors associated with fewer STIs were age at first intercourse (17% reduction per year of delayed intercourse, 95% CI 5-28%); and learning about sex from lessons at school (85% reduction, 95% CI 32-97%), from friends of the same age (54% reduction, CI 7-77%) and from first boy/girlfriend (85% reduction, 95% CI 35-97%) compared with learning from ones mother. CONCLUSION School-based sexual education is effective at reducing the risk of unprotected intercourse and STIs in early adulthood. Influence from friends in adolescence may also have a positive effect on the risk of STIs in later life.

Foreign travel associated with increased sexual risk-taking, alcohol and drug use among UK university students: a cohort study.

We conducted a prospective cohort study to assess sexual behaviour of students at a British University during the summer break, to explore the role of foreign travel as a risk factor of sexually transmitted infections acquisition and to determine characteristics associated with casual sex. We found that those who travelled abroad were more likely to use alcohol (RR 1.59, 95% CI 1.17–2.16) and cannabis (RR 1.35, 95% CI 1.13–1.62) and to have casual sex during holidays. They also reported more sexual relationships after holidays (RR 1.26, 95% CI 1.09–1.53). New partnerships during holidays were associated with being single, foreign travel, drinking alcohol and having previously had large number of sexual partners. The adjusted relative risk of developing new sexual partnerships with foreign travel was 2.70 (95% CI 1.11–6.61). People who travel abroad during holidays are more likely to engage in risk taking behaviour and have casual sex. They are also more sexually active after holidays.

Sex, drugs and sexually transmitted infections in British university students

Summary: Understanding predisposing factors for sexually transmitted infections (STIs) in young adults may identify targets for public health interventions. We conducted a cross-sectional web-based survey of university students’ sexual attitudes, behaviours and lifestyles and self-reported rates of STI. A total of 827 students responded, 22.4% had two or more sexual partners in the previous year with inconsistent condom use and the lifetime prevalence of STIs was 9.6%. Factors associated with a diagnosis of STI were increasing age and number of sexual partners ever, female gender (adjusted odds ratio [AOR] 2.70, 95% confidence interval [CI] 1.31, 5.56) and use of crack (AOR 10.45, 95% CI 1.46, 75.16). For female students, these were increasing age and number of partners ever, whereas for male students having sex with other men (bisexual AOR 4.8, 95% CI 1.02, 22.595, homosexual AOR 17.66, 95% CI 3.03, 103.04) and use of crack (AOR 32.24, 95% CI 3.33, 312.08). Multiple partners and recreational drug use may predict incidence of STI. Prevention strategies need to aim at reducing risk behaviour across various activities.

Early impact of rotavirus vaccination in a large paediatric hospital in the UK

The impact of routine rotavirus vaccination on community-acquired (CA) and healthcare-associated (HA) rotavirus gastroenteritis (RVGE) at a large paediatric hospital, UK, was investigated over a 13-year period. A total of 1644 hospitalized children aged 0-15 years tested positive for rotavirus between July 2002 and June 2015. Interrupted time-series analysis demonstrated that, post vaccine introduction (July 2013 to June 2015), CA- and HA-RVGE hospitalizations were 83% [95% confidence interval (CI): 72-90%) and 83% (95% CI: 66-92%] lower than expected, respectively. Rotavirus vaccination has rapidly reduced the hospital rotavirus disease burden among both CA- and HA-RVGE cases.

Foreign Travel and Decreased Ciprofloxacin Susceptibility in Salmonella enterica Infections

To determine antimicrobial drug resistance patterns, we characterized nontyphoidal Salmonella enterica strains isolated in Liverpool, UK, January 2003 through December 2009. Decreased susceptibility to ciprofloxacin was found in 103 (20.9%) of 492 isolates. The lower susceptibility was associated with ciprofloxacin treatment failures and with particular serovars and phage types often acquired during foreign travel.

The effect of measles on health-related quality of life: a patient-based survey.

Background Measles is a highly contagious and potentially fatal illness preventable through vaccination. Outbreaks in the UK and many other European countries have been increasing over recent years, with over 3,207 laboratory-confirmed cases reported by Public Health England from January 2012 to the end of June 2013. To aid rational decision making regarding measles control versus other use of healthcare resources, it is important to measure the severity of measles in units that are comparable to other diseases. The standard metric for this in the UK is the quality-adjust life year (QALY). To our knowledge, the impact of measles on health-related quality of life (HRQoL) in terms of QALYs has not been quantified. Methods and Findings Individuals with confirmed measles were sent questionnaires requesting information on the short-term impact of the illness on their HRQoL using the EuroQol EQ-5D-3L questionnaire. HRQoL was reported for the day the questionnaire was received, the worst day of infection and at follow-up three weeks later. 507 questionnaires were sent to individuals with confirmed measles with 203 returned (40%). The majority of respondents were not vaccinated. The mean time off work or school was 9.6 days. The mean duration of perceived illness was 13.8 days. The mean number of QALYs lost was 0.019 (equivalent to 6.9 days). The overall burden of disease in terms of QALYs lost in England based on the total number of confirmed cases in the twelve month period from 1st June 2012 was estimated to be 44.2 QALYs. Conclusion The short-term impact of measles infection on HRQoL is substantial, both at the level of the individual patient and in terms of the overall disease burden. This is the first attempt to quantify QALY-loss due to measles at a population level, and provides important parameters to guide future intervention and control measures.

Effect of socioeconomic deprivation on uptake of measles, mumps and rubella vaccination in Liverpool, UK over 16 years: a longitudinal ecological study

Suboptimal uptake of the measles, mumps and rubella (MMR) vaccine by certain socioeconomic groups may have contributed to recent large measles outbreaks in the UK. We investigated whether socioeconomic deprivation was associated with MMR vaccine uptake over 16 years. Using immunization data for 72,351 children born between 1995 and 2012 in Liverpool, UK, we examined trends in vaccination uptake. Generalized linear models were constructed to examine the relative effect of socioeconomic deprivation and year of birth on MMR uptake. Uptake of MMR1 by age 24 months ranged between 82·5% in 2003 [95% confidence interval (CI) 81·2-83·7] and 93·4% in 2012 (95% CI 92·7-94·2). Uptake of MMR2 by age 60 months ranged between 65·3% (95% CI 64·4-67·4) in 2006 and 90·3% (95% CI 89·4-91·2) in 2012. In analysis adjusted for year of birth and sex, children in the most deprived communities were at significantly greater risk of not receiving MMR1 [risk ratio (RR) 1·70, 95% CI 1·45-1·99] and MMR2 (RR 1·36, 95% CI 1·22-1·52). Higher unemployment and lower household income were significantly associated with low uptake. Contrary to concerns about lower MMR uptake in affluent families, over 16 years, children from the most socioeconomically deprived communities have consistently had the lowest MMR uptake. Targeted catch-up campaigns and strategies to improve routine immunization uptake in deprived areas are needed to minimize the risk of future measles outbreaks.