Comparing healthcare needs by language: interpreted Arabic and Somali telehealth calls in two regions of Sweden, 2014-18.

BACKGROUND: Limited language fluency can impede healthcare system navigation. In Sweden, the national telehealth line (Healthcare Guide 1177) offers interpretation in Arabic and Somali. We compared calls by language to identify differences in healthcare use for immigrant populations, focusing on three contact causes: pregnancy; vomiting or nausea in children; and worry/anxiety. METHODS: We conducted a cross-sectional analysis of 3.9 million (n = 18 351 Arabic, n = 7199 Somali) telehealth calls (2014-18). Using multivariable logistic regression, we investigated associations between language of the call (Arabic, Somali, non-interpreted) and each contact cause. Potential confounders (age, region, year, and additionally for vomiting or nausea, month) and an interaction between age and language were considered. RESULTS: Compared with non-interpreted calls, interpreted calls were associated with increased odds of being for pregnancy, especially for 19 to 29-year-olds [adjusted odds ratio (aOR) (95% CI) = 4.04 (3.66-4.46) and 4.60 (4.05-5.23), for Arabic and Somali calls, respectively]. Vomiting or nausea showed similar results, with aOR increasing with age: from 0.90 (0.75-1.07) (Arabic, <1 year) to 3.79 (2.86-5.01) (Somali, 5-9 years). In contrast, in unadjusted analyses, Arabic and Somali calls were associated with decreased odds of being for worry/anxiety [OR = 0.47 (0.38-0.58) and 0.34 (0.21-0.50)], respectively, compared with non-interpreted calls. CONCLUSION: Our results suggest callers to the interpreted lines may need additional assistance navigating the healthcare system for pregnancy and for vomiting or nausea among children. These findings can inform healthcare services planning for immigrants to Sweden and highlight a novel use of telehealth data as a way to uncover disparities in healthcare use within a multi-linguistic population.

Outbreak of Salmonella Typhimurium linked to Swedish pre-washed rocket salad, Sweden, September to November 2022.

In September 2022, the Public Health Agency of Sweden observed an increase in domestic Salmonella Typhimurium cases through the Swedish electronic notification system, and an outbreak strain was identified with whole genome sequencing. Overall, 109 cases with symptom onset between 17 September and 24 November 2022 were reported from 20 of 21 Swedish regions. The median age of cases was 52 years (range 4-87 years) and 62% were female. A case-control study found cases to be associated with consumption of rocket salad (adjusted odds ratio (aOR) = 4.9; 95% confidence interval (CI): 2.4-10, p value < 0.001) and bagged mixed salad (aOR = 4.0; 95% CI: 1.9-8.1, p value < 0.001). Trace-back, supported by Finnish authorities who identified the Swedish outbreak strain in a Finnish cluster during the same time period, identified rocket salad, cultivated, pre-washed and pre-packed in Sweden as the likely source of the outbreak. No microbiological analyses of rocket salad were performed. Our investigation indicates that bagged leafy greens such as rocket salad, regardless of pre-washing procedures in the production chain, may contain Salmonella and cause outbreaks, posing a health risk to consumers. We emphasise the need for primary producers of leafy greens to identify possible contamination points to prevent outbreaks.

Point prevalence of SARS-CoV-2 infection in Sweden at six time points during 2020.

BACKGROUND: In order to estimate the prevalence and understand the spread of SARS-CoV-2 in Sweden, the Public Health Agency of Sweden, with support from the Swedish Armed Forces, conducted a series of point prevalence surveys between March and December 2020. METHODS: Sampling material and instructions on how to perform self-sampling of the upper respiratory tract were delivered to the homes of the participants. Samples were analysed by real-time PCR, and the participants completed questionnaires regarding symptoms. FINDINGS: The first survey in the Stockholm region in March 2020 included 707 participants and showed a SARS-CoV-2 prevalence of 2.5%. The following five surveys, performed on a national level, with between 2461 and 2983 participants, showed SARS-CoV-2 prevalences of 0.9% (April), 0.3% (May), 0.0% (August), 0.0% (September), and 0.7% (December). All positive cases who responded to questionnaires reported experiencing symptoms that occurred from 2 weeks before the date of sampling up to and including the date of sampling. INTERPRETATION: None of the individuals shown to be PCR-positive were asymptomatic at the time of sampling or in the 14 days prior to sampling. This is in contrast to many other surveys in which a substantial proportion of positive cases have been reported to be asymptomatic. Our surveys demonstrate a decreasing ratio between notified cases and the observed prevalence throughout the year, in line with increasing testing capacity and the consecutive inclusion of all symptomatic individuals in the case definition for testing.

Patterns of sexual behaviour associated with repeated chlamydia testing and infection in men and women: a latent class analysis.

BACKGROUND: Adolescents and young adults are at higher risk of acquiring Chlamydia trachomatis infection (chlamydia), so testing is promoted in these populations. Studies have shown that re-testing for chlamydia is common amongst them. We investigated how sexual risk behaviour profiles are associated with repeated testing for chlamydia. METHODS: We used baseline data from a cohort of 2814 individuals recruited at an urban STI -clinic. We applied latent class (LC) analysis using 9 manifest variables on sexual behaviour and substance use self-reported by the study participants. We fitted ordered logistic regression to investigate the association of LC membership with the outcomes repeated testing during the past 12 months and lifetime repeated testing for chlamydia. Models were fit separately for men and women. RESULTS: We identified four LCs for men and three LCs for women with increasing gradient of risky sexual behaviour. The two classes with the highest risk among men were associated with lifetime repeated testing for chlamydia: adjOR = 2.26 (95%CI: 1.50-3.40) and adjOR = 3.03 (95%CI: 1.93-4.74) as compared with the class with lowest risk. In women, the class with the highest risk was associated with increased odds of repeated lifetime testing (adjOR =1.85 (95%CI: 1.24-2.76)) and repeated testing during past 12 months (adjOR = 1.72 (95%CI: 1.16-2.54)). An association with chlamydia positive test at the time of the study and during the participant's lifetime was only found in the male highest risk classes. CONCLUSION: Prevention messages with regard to testing for chlamydia after unprotected sexual contact with new/casual partners seem to reach individuals in highest risk behaviour classes who are more likely to test repeatedly. Further prevention efforts should involve potentially more tailored sex-specific interventions taking into consideration risk behaviour patterns.

Changes in the Trend of Sexually Acquired Chlamydia Infections in Sweden and the Role of Testing: A Time Series Analysis.

BACKGROUND: We investigated the notification trends of sexually acquired chlamydia (chlamydia) and its association with testing in Sweden before (1992-2004) and after (2009-2018) the discovery of a new variant of Chlamydia trachomatis (nvCT). METHODS: We applied monthly time series analysis to study chlamydia trends and annual time series to study chlamydia rates adjusted for testing. We analyzed incidence nationally and by county group (based on able and unable to detect nvCT at time of discovery). RESULTS: We present data on 606,000 cases of chlamydia and 9.9 million persons tested. We found a U-shaped chlamydia trend during the period 1992-2004, with an overall increase of 83.7% from 1996 onward. The period 2009-2018 began with a stable trend at a high incidence level followed by a decrease of 19.7% during the period 2015-2018. Peaks were seen in autumn and through during winter and summer. Similar results were observed by groups of county, although with varying levels of increase and decrease in both periods. Furthermore, increased testing volume was associated with increased chlamydia rates during the first period (P = 0.019) but not the second period. CONCLUSIONS: Our results showed that chlamydia trends during the period 2009-2018 were not driven by testing, as they were during the period 1992-2004. This suggests less biased notified chlamydia rates and thus possibly a true decrease in chlamydia incidence rates. It is important to adjust case rates for testing intensity, and future research should target other potential factors influencing chlamydia rates.

An outbreak investigation of Legionella non-pneumophila Legionnaires' disease in Sweden, April to August 2018: Gardening and use of commercial bagged soil associated with infections.

In early June 2018, an increase in non-travel-related cases of Legionella non-pneumophila Legionnaires' disease (LD) was observed in Sweden and a national outbreak investigation was started. Outbreak cases were defined as notified confirmed or probable cases of L. non-pneumophila LD, with symptom onset after 1 April 2018. From April to August 2018, 41 cases were reported, 30 of whom were identified as L. longbeachae. We conducted a case-control study with 27 cases and 182 matched controls. Results from the case-control study indicated that gardening and handling commercial bagged soil, especially dusty dry soil, were associated with disease. L. longbeachae was isolated in soils from cases' homes or gardens, but joint analysis of soil and human specimens did not identify any genetic clonality. Substantial polyclonality was noted between and within soil samples, which made finding a genetic match between soil and human specimens unlikely. Therefore, whole genome sequencing may be of limited use to confirm a specific soil as a vehicle of transmission for L. longbeachae. Handling soil for residential gardening was associated with disease and the isolation of L. longbeachae in different soils provided further evidence for Legionella non-pneumophila infection from soil.

Increased risk of active tuberculosis during pregnancy and postpartum: a register-based cohort study in Sweden.

RATIONALE: Studies investigating the risk of active tuberculosis (TB) in association with pregnancy have not been conclusive. We aimed to investigate this risk in a large retrospective register-based cohort study in Sweden. METHODS: Data from women of 15-49 years of age who had given birth in Sweden between 2005 and 2013 were extracted from the national childbirth register and linked to the national TB register. Cohort time was divided into three exposure periods: during pregnancy, six months (180 days) postpartum and time neither pregnant nor postpartum. We calculated incidence rates (IRs) per 100 000 person-years for each period and incidence rate ratios (IRRs) with IRs neither pregnant nor postpartum as the reference. RESULTS: The cohort included 649 342 women, of whom 553 were registered as cases of active TB, 389 when neither pregnant nor postpartum, 85 during pregnancy and 79 when postpartum. Overall IRs were 9, 12 and 17 cases per 100 000 person-years, respectively, giving IRR 1.4, 95% CI 1.1-1.7 (during pregnancy) and IRR 1.9, 95% CI 1.5-2.5 (when postpartum). Stratification by TB incidence in country of origin showed that the increased risk was concentrated amongst women from countries with a TB incidence of 100 or higher, where IRs per 100 000 person-years were 137 (when neither pregnant nor postpartum), 182 (during pregnancy) and 233 (when postpartum). CONCLUSION: We show a significant increase in risk of active TB during both pregnancy and postpartum in women from high incidence countries and recommend TB screening in pregnant women belonging to this risk group.

Cross-border outbreak of Yersinia enterocolitica O3 associated with imported fresh spinach, Sweden and Denmark, March 2019.

In April 2019, a cross-border outbreak of Yersinia entercolitica O3 was identified in Sweden and Denmark and confirmed using whole genome sequencing. Close cross-border collaboration with representatives from human and food authorities helped direct resources and investigations. Combined epidemiological and trace-back investigations pointed to imported fresh spinach as the outbreak vehicle and highlight that other vehicles of Y. enterocolitica outbreaks than pork should be considered.

Outbreak of unusual H2S-negative monophasic Salmonella Typhimurium strain likely associated with small tomatoes, Sweden, August to October 2019.

Sweden is investigating an outbreak of monophasic Salmonella Typhimurium. Eighty-two nationally-distributed cases have been confirmed, with date of symptom onset between 28 August and 29 October. Cases were 51 years of age on average (range: 0-89) and the majority of cases were female (62%). A case-control study was conducted and suggested small tomatoes as source of the outbreak (adjusted odds ratio (OR): 10.8, 95% confidence interval (CI): 4.15-112.68, p value < 0.001), and a trace-back investigation led to a single, non-Swedish producer in Europe. Both the Salmonella strain and the source of the outbreak are rarely encountered in Europe. Results from investigation at the producer are pending.

Quantifying unmet prevention needs among MSM in Europe through a multi-site bio-behavioural survey.

IntroductionThe HIV epidemic represents an important public health issue in Europe particularly among men who have sex with men (MSM). Global AIDS Monitoring indicators (GAM) have been widely and jointly promoted as a set of crucial standardised items to be adopted for monitoring and responding to the epidemic.MethodsThe Sialon II study, implemented in 13 European cities (2013-14), was a complex multi-centre integrated bio-behavioural cross-sectional survey targeted at MSM, with a concomitant collection of behavioural and biological (oral fluid or blood specimens) data. Rigorous sampling approaches for hard-to-reach populations were used (time-location sampling and respondent-driven sampling) and GAM indicators were calculated; sampling frames were adapted to allow weighted estimates of GAM indicators.Results4,901 MSM were enrolled. HIV prevalence estimates ranged from 2.4% in Stockholm to 18.0% in Bucharest. When exploring city-level correlations between GAM indicators, prevention campaigns significantly correlated with levels of condom use and level of HIV testing among MSM.ConclusionThe Sialon II project has made an important contribution to the monitoring and evaluation of the HIV epidemic across Europe, integrating the use of GAM indicators within a second generation HIV surveillance systems approach and in participatory collaboration with MSM communities. It influenced the harmonisation of European data collection procedures and indicators via GAM country reporting and contributed essential knowledge informing the development and implementation of strategic, evidence-based HIV prevention campaigns for MSM.

Bio-behavioural HIV and STI surveillance among men who have sex with men in Europe: the Sialon II protocols.

BACKGROUND: Globally, the HIV epidemic continues to represent a pressing public health issue in Europe and elsewhere. There is an emerging and progressively urgent need to harmonise HIV and STI behavioural surveillance among MSM across European countries through the adoption of common indicators, as well as the development of trend analysis in order to monitor the HIV-STI epidemic over time. The Sialon II project protocols have been elaborated for the purpose of implementing a large-scale bio-behavioural survey among MSM in Europe in line with a Second Generation Surveillance System (SGSS) approach. METHODS/DESIGN: Sialon II is a multi-centre biological and behavioural cross-sectional survey carried out across 13 European countries (Belgium, Bulgaria, Germany, Italy, Lithuania, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, and the UK) in community settings. A total of 4,966 MSM were enrolled in the study (3,661 participants in the TLS survey, 1,305 participants in the RDS survey). Three distinct components are foreseen in the study protocols: first, a preliminary formative research in each participating country. Second, collection of primary data using two sampling methods designed specifically for 'hard-to-reach' populations, namely Time Location Sampling (TLS) and Respondent Driven Sampling (RDS). Third, implementation of a targeted HIV/STI prevention campaign in the broader context of the data collection. DISCUSSION: Through the implementation of combined and targeted prevention complemented by meaningful surveillance among MSM, Sialon II represents a unique opportunity to pilot a bio-behavioural survey in community settings in line with the SGSS approach in a large number of EU countries. Data generated through this survey will not only provide a valuable snapshot of the HIV epidemic in MSM but will also offer an important trend analysis of the epidemiology of HIV and other STIs over time across Europe. Therefore, the Sialon II protocol and findings are likely to contribute significantly to increasing the comparability of data in EU countries through the use of common indicators and in contributing to the development of effective public health strategies and policies in areas of high need.

The incidence of acute gastrointestinal illness in Sweden.

AIMS: The aim of this study was to estimate the self-reported domestic incidence of acute gastrointestinal illness in the Swedish population irrespective of route of transmission or type of pathogen causing the disease. Previous studies in Sweden have primarily focused on incidence of acute gastrointestinal illness related to consumption of contaminated food and drinking water. METHODS: In May 2009, we sent a questionnaire to 4000 randomly selected persons aged 0-85 years, asking about the number of episodes of stomach disease during the last 12 months. To validate the data on symptoms, we compared the study results with anonymous queries submitted to a Swedish medical website. RESULTS: The response rate was 64%. We estimated that a total number of 2744,778 acute gastrointestinal illness episodes (95% confidence intervals 2475,641-3013,915) occurred between 1 May 2008 and 30 April 2009. Comparing the number of reported episodes with web queries indicated that the low number of episodes during the first 6 months was an effect of seasonality rather than recall bias. Further, the result of the recall bias analysis suggested that the survey captured approximately 65% of the true number of episodes among the respondents. CONCLUSIONS: The estimated number of Swedish acute gastrointestinal illness cases in this study is about five times higher than previous estimates this study provides valuable information on the incidence of gastrointestinal symptoms in Sweden, irrespective of route of transmission, indicating a high burden of acute gastrointestinal illness, especially among children, and large societal costs, primarily due to production losses.

Is case-chaos methodology an appropriate alternative to conventional case-control studies for investigating outbreaks?

Case-chaos methodology is a proposed alternative to case-control studies that simulates controls by randomly reshuffling the exposures of cases. We evaluated the method using data on outbreaks in Sweden. We identified 5 case-control studies from foodborne illness outbreaks that occurred between 2005 and 2012. Using case-chaos methodology, we calculated odds ratios 1,000 times for each exposure. We used the median as the point estimate and the 2.5th and 97.5th percentiles as the confidence interval. We compared case-chaos matched odds ratios with their respective case-control odds ratios in terms of statistical significance. Using Spearman's correlation, we estimated the correlation between matched odds ratios and the proportion of cases exposed to each exposure and quantified the relationship between the 2 using a normal linear mixed model. Each case-control study identified an outbreak vehicle (odds ratios = 4.9-45). Case-chaos methodology identified the outbreak vehicle 3 out of 5 times. It identified significant associations in 22 of 113 exposures that were not associated with outcome and 5 of 18 exposures that were significantly associated with outcome. Log matched odds ratios correlated with their respective proportion of cases exposed (Spearman ρ = 0.91) and increased significantly with the proportion of cases exposed (b = 0.054). Case-chaos methodology missed the outbreak source 2 of 5 times and identified spurious associations between a number of exposures and outcome. Measures of association correlated with the proportion of cases exposed. We recommended against using case-chaos analysis during outbreak investigations.

Associations of hand-washing frequency with incidence of acute respiratory tract infection and influenza-like illness in adults: a population-based study in Sweden.

BACKGROUND: Frequent hand-washing is standard advice for avoidance of respiratory tract infections, but the evidence for a preventive effect in a general community setting is sparse. We therefore set out to quantify, in a population-based adult general population cohort, the possible protection against acute respiratory tract infections (ARIs) conferred by a person's self-perceived hand-washing frequency. METHODS: During the pandemic influenza season from September 2009 through May 2010, a cohort of 4365 adult residents of Stockholm County, Sweden, reported respiratory illnesses in real-time. A questionnaire about typical contact and hand-washing behaviour was administered at the end of the period (response rate 70%). RESULTS: There was no significant decrease in ARI rates among adults with increased daily hand-washing frequency: Compared to 2-4 times/day, 5-9 times was associated with an adjusted ARI rate ratio (RR) of 1.08 (95% confidence interval [CI] 0.87-1.33), 10-19 times with RR = 1.22 (CI 0.97-1.53), and ≥20 times with RR = 1.03 (CI 0.81-1.32). A similar lack of effect was seen for influenza-like illness, and in all investigated subgroups. We found no clear effect modification by contact behaviour. Health care workers exhibited rate ratio point estimates below unity, but no dose-risk trend. CONCLUSIONS: Our results suggest that increases in what adult laymen perceive as being adequate hand-washing may not significantly reduce the risk of ARIs. This might have implications for the design of public health campaigns in the face of threatening outbreaks of respiratory infections. However, the generalizability of our results to non-pandemic circumstances should be further explored.

Molecular epidemiology of community- and hospital-associated Clostridioides difficile infections in Jönköping, Sweden, October 2017 - March 2018.

Clostridioides difficile infections (CDIs) in Sweden are mostly hospital-associated (HA) with limited knowledge regarding community-associated (CA) infections. Here, we investigated the molecular epidemiology of clinical isolates of CA-CDI and HA-CDI in a Swedish county. Data and isolates (n = 156) of CDI patients (n = 122) from Jönköping county, October 2017-March 2018, were collected and classified as CA (without previous hospital care or onset ≤2 days after admission or >12 weeks after discharge from hospital) or HA (onset >3 days after hospital admission or within 4 weeks after discharge). Molecular characterization of isolates included PCR ribotyping (n = 156 isolates) and whole genome sequencing with single nucleotide polymorphisms (SNP) analysis (n = 53 isolates). We classified 47 patients (39%) as CA-CDI and 75 (61%) as HA-CDI. Between CA-CDI and HA-CDI patients, we observed no statistically significant differences regarding gender, age, 30-day mortality or recurrence. Ribotype 005 (RR 3.1; 95% CI: 1.79-5.24) and 020 (RR 2.5; 95% CI: 1.31-4.63) were significantly associated with CA-CDI. SNP analysis identified seven clusters (0-2 SNP difference) involving 17/53 isolates of both CA-CDI and HA-CDI. Molecular epidemiology differed between CA-CDI and HA-CDI and WGS analysis suggests transmission of CDI within and between hospitals and communities.

Seroprevalence of SARS-CoV-2 in Sweden, April 26 to May 9, 2021.

A national point seroprevalence study of SARS-CoV-2 was conducted in Sweden in April-May 2021. In total, 2860 individuals 3 to 90 years old from a probability-based web panel were included. Results showed that an estimated 32.6% of the population in Sweden had detectable levels of antibodies, and among non-vaccinated 20.1% had detectable levels of antibodies. We tested for differences in seroprevalence between age groups and by sex and estimated seroprevalence among previously infected participants by time since reporting.

Pertussis seroprevalence among adults of reproductive age (20-39 years) in fourteen European countries.

The reported incidence of pertussis in European countries varies considerably. We aimed to study specific Bordetella pertussis seroprevalence in Europe by measuring serum IgG antibody levels to pertussis toxin (anti-PT IgG). Fourteen national laboratories participated in this study including Belgium, Denmark, Finland, Greece, Hungary, Italy, Lithuania, Malta, Norway, Poland, Portugal, Romania, Spain, and Sweden. Each country collected approximately 250 samples (N = 7903) from the age groups 20-29 years (N = 3976) and 30-39 years (N = 3927) during 2010-2013. Samples were anonymous residual sera from diagnostic laboratories and were analyzed at the national laboratories by a Swedish reference method, a commercial ELISA kit, or were sent to Sweden for analysis. The median anti-PT IgG concentrations ranged from 4 to 13.6 IU/mL. The proportion of samples with anti-PT IgG ≥100 IU/mL, indicating a recent infection ranged from 0.2% (Hungary) to 5.7% (Portugal). The highest proportion of sera with anti-PT IgG levels between 50 and <100 IU/mL, indicating an infection within the last few years, was found in Portugal (12.3%) and Italy (13.9%). This study shows that the circulation of B. pertussis is quite extensive in adults, aged 20-39 years, despite well-established vaccination programs in Europe.

High content cellular immune profiling reveals differences between rhesus monkeys and men.

A better understanding of similarities and differences in the composition of the cellular immune system in non-human primates (NHPs) compared with human subjects will improve the interpretation of preclinical studies. It will also aid in addressing the usefulness of NHPs as subjects for studying chronic diseases, vaccine development and immune reconstitution. We employed high content colour flow cytometry and analysed simultaneously the expression of CD3, CD4, CD8alpha, CD8beta, CD16/CD56, CD45RA, CCR7, CD27, CD28, CD107a and the interleukin-7 receptor alpha-chain (IL-7Ralpha) in peripheral blood mononuclear cells (PBMCs) of 27 rhesus macaques and 16 healthy human subjects. Regulatory T cells (Tregs) were identified using anti-CD3, -CD4, -CD25, -FoxP3, and -IL-7Ralpha monoclonal antibodies. Responsiveness to IL-7 was gauged in a signal transducer and activation of transcription 5 (STAT-5) phosphorylation assay. Human and NHP PBMCs showed a similar T-cell composition pattern with some remarkable differences. Similarities: human and NHP CD4(+) and CD8(+) cells showed a similar STAT-5 phosphorylation pattern in response to IL-7. Multicolour flow cytometric analysis identified a CD4(+) CD8alphaalpha(+) CD8alphabeta(+) T-cell population in NHPs as well as in human subjects that expressed the degranulation marker CD107a and may represent a unique CD4(+) T-cell subset endowed with cytotoxic capacity. Differences: we identified in PBMCs from NHPs a higher proportion (5.16% in CD3(+) T cells) of CD8alphaalpha(+) T cells when compared with human donors (1.22% in CD3(+) T cells). NHP CD8alphaalpha(+) T cells produced tumour necrosis factor-alpha / interferon-gamma (TNF-alpha/IFN-gamma) or TNF-alpha, whereas human CD8alphaalpha(+) T cells produced simultaneously TNF-alpha/IFN-gamma and IL-2. A minor percentage of human CD8(+) T cells expressed CD25(bright) and FoxP3 (0.01%). In contrast, 0.07% of NHP CD8(+) T cells exhibited the CD25(bright) FoxP3(+) phenotype. PBMCs from NHPs showed less IL-7Ralpha-positive events in all T-cell subsets including CD4(+) Tregs (median 5%) as compared with human (median 12%). The data visualize commonalities and differences in immune cell subsets in humans and NHPs, most of them in long-lived memory cells and cells with suppressive functions. This provides a matrix to assess future efforts to study diseases and vaccines in NHPs.

Interactive voice response and web-based questionnaires for population-based infectious disease reporting.

The authors aimed to evaluate the web and an Interactive Voice Response (IVR) phone service as vehicles in population-based infectious disease surveillance. Fourteen thousand subjects were randomly selected from the Swedish population register and asked to prospectively report all respiratory tract infections, including Influenza-like Illness (ILI-clinical symptoms indicative of influenza but no laboratory confirmation), immediately as they occurred during a 36-week period starting October 2007. Participants were classified as belonging to the web or IVR group based on their choice of technology for initial registration. In all, 1,297 individuals registered via IVR while 2,044 chose the web. The latter were more often young and well-educated than those registered via IVR. Overall, 52% of the participants reported at least one infection episode. The risk of an infectious disease report was 14% (95% CI: 6, 22%) higher in the web group than in the IVR group. For ILI the excess was 27% (95% CI: 11, 47%). After adjustments for socio-demographic factors, statistically non-significant excesses of 1 and 8% remained, indicating trivial differences potentially attributable to the two reporting techniques. With attention to confounding, it should be possible to combine the web and IVR for simple reporting of infectious disease symptoms.

SMS versus telephone interviews for epidemiological data collection: feasibility study estimating influenza vaccination coverage in the Swedish population.

This study compared the use of Short Message Service (SMS) on mobile phones and the use of telephone interviews in collecting self-reported data about influenza vaccination. Through random selection from the Swedish population registry, 2,400 individuals were assigned to be contacted through SMS (SMS-group), and 2,150 were assigned to undergo personal telephone interviews (TI-group). Both groups were asked three questions about influenza and influenza vaccination. Mobile phone numbers were found for 1,055 persons in the SMS-group of whom 154 (6% of the original sample; 15% of all who had a listed mobile phone number) responded. Landline or mobile phone numbers were found for 1,636 persons in the TI-group and 1,009 (47% of the original TI sample; 62% of those where a telephone number was found) responded. The vaccination data collected via SMS was not statistically significantly different from data collected through telephone interviews, and adjustment for different background factors did not change this. Compared to the original sample, there was an under representation of elderly and less educated individuals among the participants in the SMS-group, and under representation of less educated in the TI-group. Though the participation rate was low, SMS is a feasible method for collection of information on vaccination status data among the Swedish population compared to telephone interviews.