Joanne Freedman

Chikungunya outbreak in the Caribbean region, December 2013 to March 2014, and the significance for Europe

On 6 December 2013, two laboratory-confirmed cases of chikungunya without a travel history were reported on the French part of the Caribbean island of Saint Martin, indicating the start of the first documented outbreak of chikungunya in the Americas. Since this report, the virus spread to several Caribbean islands and French Guiana, and between 6 December 2013 and 27 March 2014 more than 17,000 suspected and confirmed cases have been reported. Further spread and establishment of the disease in the Americas is likely, given the high number of people travelling between the affected and non-affected areas and the widespread occurrence of efficient vectors. Also, the likelihood of the introduction of the virus into Europe from the Americas and subsequent transmission should be considered especially in the context of the next mosquito season in Europe. Clinicians should be aware that, besides dengue, chikungunya should be carefully considered among travellers currently returning from the Caribbean region.

East London experience with enteric fever 2007-2012.

Purpose The clinical presentation and epidemiology for patients with enteric fever at two hospitals in East London during 2007–2012 is described with the aim to identify preventive opportunities and to reduce the cost of treatment. Methods A retrospective analysis of case notes from patients admitted with enteric fever during 2007 to 2012 with a microbiologically confirmed diagnosis was undertaken. Details on clinical presentation, travel history, demographic data, laboratory parameters, treatment, patient outcome and vaccination status were collected. Results Clinical case notes were available for 98/129 (76%) patients including 69 Salmonella enterica serovar Typhi (S. Typhi) and 29 Salmonella enterica serovar Paratyphi (S. Paratyphi). Thirty-four patients (35%) were discharged from emergency medicine without a diagnosis of enteric fever and then readmitted after positive blood cultures. Seventy-one of the 98 patients (72%) were UK residents who had travelled abroad, 23 (23%) were foreign visitors/new entrants to the UK and four (4%) had not travelled abroad. Enteric fever was not considered in the initial differential diagnosis for 48/98 (49%) cases. The median length of hospital stay was 7 days (range 0–57 days). The total cost of bed days for managing enteric fever was £454,000 in the two hospitals (mean £75,666/year). Median time to clinical resolution was five days (range 1–20). Seven of 98 (7%) patients were readmitted with relapsed or continued infection. Six of the 71 (8%) patients had received typhoid vaccination, 34 (48%) patients had not received vaccination, and for 31 cases (44%) vaccination status was unknown. Conclusions Further interventions regarding education and vaccination of travellers and recognition of the condition by emergency medicine clinicians in travellers to South Asia is required.

Comparison of phenotypic and WGS-derived antimicrobial resistance profiles of Salmonella enterica serovars Typhi and Paratyphi

Objectives Surveillance of antimicrobial resistance (AMR) in Salmonella enterica serovars Typhi and Paratyphi is essential to provide an evidence base for empirical treatment protocols and to monitor emerging AMR. We sought to compare phenotypic and WGS-based genotypic methods for the detection of AMR in Salmonella Typhi and Salmonella Paratyphi. Methods WGS data from 603 isolates of Salmonella Typhi (n = 332) and Salmonella Paratyphi (n = 271) were mapped to genes or chromosomal mutations known to be associated with phenotypic AMR and compared with phenotypic susceptibility data interpreted using breakpoints recommended by EUCAST. Results There were two (0.03%) discordant interpretations out of a possible 6030 isolate/antimicrobial class combinations. MDR (resistant to three or more classes of antimicrobial) was detected in 83/332 (25.0%) Salmonella Typhi isolates, but was not detected in Salmonella Paratyphi. Thirty-six (10.8%) isolates of Salmonella Typhi were resistant to ciprofloxacin (MIC >0.5 mg/L), with 33 (9.9%) of 332 exhibiting mutations in gyrA and parC, and 244 (73.5%) isolates had reduced susceptibility to ciprofloxacin (MIC 0.06-0.25 mg/L). In comparison, 209/227 (92.1%) isolates of Salmonella Paratyphi A exhibited resistance to ciprofloxacin (MIC >0.5 mg/L). No resistance to azithromycin or the third-generation cephalosporins was detected. Conclusions WGS data provided a robust and informative approach for monitoring MDR and emerging resistance to ciprofloxacin in Salmonella Typhi and Salmonella Paratyphi. Phenotypic antimicrobial susceptibility testing continues to be performed to guide targeted individual patient treatment, but inferred AMR profiles from WGS data may be used for surveillance and to guide empirical therapy.

Cyclospora infection linked to travel to Mexico, June to September 2015

Cyclospora cayetanensis was identified in 176 returned travellers from the Riviera Maya region of Mexico between 1 June and 22 September 2015; 79 in the United Kingdom (UK) and 97 in Canada. UK cases completed a food exposure questionnaire. This increase in reported Cyclospora cases highlights risks of gastrointestinal infections through travelling, limitations in Cyclospora surveillance and the need for improved hygiene in the production of food consumed in holiday resorts.

Defining travel-associated cases of enteric fever

There is no internationally recognized case-definition for travel-associated enteric fever in non-endemic countries. This study describes the patterns of case reporting between 2007 and 2011 as travel-associated or not from the surveillance data in England, Wales and Northern Ireland (EWNI), before and after a change in the time component of the case-definition in January 2011. It examines in particular the role of a time frame based on the reported typical incubation period in defining a case of travel-associated enteric fever. The results showed no significant differences in the distribution of cases of enteric fever in regards to the interval between the onset and UK arrival in 2011 compared to 2007-2010 (p=0.98 for typhoid and paratyphoid A); the distribution for paratyphoid B was also similar in both time periods. During 2007-2010, 93% (1730/1853) of all of the cases were classified as travel-associated compared to 94% (448/477) in 2011. This difference was not statistically significant. Changing the time component of the definition of travel-associated enteric fever did not make a significant difference to the proportion of travel-associated cases reported by investigators. Our analysis suggests that time might be subordinate to other considerations when investigators classify a case as travel-associated.

Trend analysis of imported malaria in London; observational study 2000 to 2014

BACKGROUND We describe trends of malaria in London (2000-2014) in order to identify preventive opportunities and we estimated the cost of malaria admissions (2009/2010-2014/2015). METHODS We identified all cases of malaria, resident in London, reported to the reference laboratory and obtained hospital admissions from Hospital Episode Statistics. RESULTS The rate of malaria decreased (19.4[2001]-9.1[2014] per 100,000). Males were over-represented (62%). Cases in older age groups increased overtime. The rate was highest amongst people of Black African ethnicity followed by Indian, Pakistani, Bangladeshi ethnicities combined (103.3 and 5.5 per 100,000, respectively). The primary reason for travel was visiting friends and relatives (VFR) in their country of origin (69%), mostly sub-Saharan Africa (92%). The proportion of cases in VFRs increased (32%[2000]-50%[2014]) and those taking chemoprophylaxis decreased (36%[2000]-14%[2014]). The overall case fatality rate was 0.3%. We estimated the average healthcare cost of malaria admissions to be just over £1 million per year. CONCLUSION Our study highlighted that people of Black African ethnicity, travelling to sub-Saharan Africa to visit friends and relatives in their country of origin remain the most affected with also a decline in chemoprophylaxis use. Malaria awareness should focus on this group in order to have the biggest impact but may require new approaches.

Cyclosporiasis in travellers returning to the United Kingdom from Mexico in summer 2017: lessons from the recent past to inform the future

During the summers of 2015 and 2016, the United Kingdom experienced large outbreaks of cyclosporiasis in travellers returning from Mexico. As the source of the outbreaks was not identified, there is the potential for a similar outbreak to occur in 2017; indeed 78 cases had already been reported as at 27 July 2017. Early communication and international collaboration is essential to provide a better understanding of the source and extent of this recurring situation.

What were the risk factors and trends in antimicrobial resistance for enteric fever in London 2005–2012?

Purpose. A study was undertaken to determine the risk factors and trends in antimicrobial resistance for enteric fever. Methodology. Demographic, antimicrobial susceptibility, typing and epidemiological data were examined for 2005‐2012 in patients with enteric fever in London. Single and multivariable logistic regression was used to determine the risk factors associated with antibiotic resistance. Results. 453 cases with Salmonella enterica subsp. enterica serovar Paratyphi A, 17 with S. Paratyphi B and 611 with S. enterica subsp. enterica serovar Typhi were examined. For travellers, 335 (88%) of S. Paratyphi A isolates were resistant to ciprofloxacin, but resistance to other antimicrobials was low. Almost 80% (395) of the S. Typhi isolates were resistant to ciprofloxacin, 131 (26%) to ampicillin, 131 (27%) to chloramphenicol, 137 (28%) to trimethoprim and 171 (28%) to sulphonamide. None of the isolates were resistant to cephalosporins. A trend analysis for S. Typhi isolates showed no significant change in resistance to ampicillin, chloramphenicol, sulphonamide and trimethoprim or for multidrug resistance (P=0.38). Overall resistance to ciprofloxacin increased for S. Paratyphi A (P=0.018) and for S. Typhi (P<0.001) but fell for S. Typhi in 2011‐2012. Resistance profiles were reflected by specific phage types and countries visited by the travellers. Conclusions. The proportion of S. Typhi strains resistant to ampicillin, chloramphenicol and cotrimoxazole remained steady for the period 2005‐2012. There was a significant increase in a trend for resistance to ciprofloxacin which increased until 2010, followed by a fall in 2011‐2012. S. Paratyphi resistance to ciprofloxacin increased until 2012. Specific phage types were associated with resistance to specific antimicrobials and travel abroad.

Early detection of perceived risk among users of a UK travel health website compared with internet search activity and media coverage during the 2015–2016 Zika virus outbreak: an observational study

Objectives The Zika virus (ZIKV) outbreak in the Americas in 2015–2016 posed a novel global threat due to the association with congenital malformations and its rapid spread. Timely information about the spread of the disease was paramount to public health bodies issuing travel advisories. This paper looks at the online interaction with a national travel health website during the outbreak and compares this to trends in internet searches and news media output. Methods Time trends were created for weekly views of ZIKV-related pages on a UK travel health website, relative search volumes for ‘Zika’ on Google UK, ZIKV-related items aggregated by Google UK News and rank of ZIKV travel advisories among all other pages between 15 November 2015 and 20 August 2016. Results Time trends in traffic to the travel health website corresponded with Google searches, but less so with media items due to intense coverage of the Rio Olympics. Travel advisories for pregnant women were issued from 7 December 2015 and began to increase in popularity (rank) from early January 2016, weeks before a surge in interest as measured by Google searches/news items at the end of January 2016. Conclusions The study showed an amplification of perceived risk among users of a national travel health website weeks before the initial surge in public interest. This suggests a potential value for tools to detect changes in online information seeking behaviours for predicting periods of high demand where the routine capability of travel health services could be exceeded.