Selective under-representation of Pacific peoples in population estimates for health indicator measurements in Aotearoa New Zealand misinforms policy making.

BACKGROUND: The Census of Populations and Dwellings' is the five yearly population count of Aotearoa New Zealand. Best available populations (BAP) are subnational projections based on census data and demographic assumptions developed for healthcare planning and funding allocation but are also used as the denominator for health indicator monitoring. Pacific people are systematically undercounted, but the impact on health statistics is not well studied. For COVID-19 vaccination coverage, health service user (HSU) data were considered a more reliable denominator than BAP but introduced new biases. We aimed to understand how the choice of denominator population impacts estimates of population size and health system performance for Pacific people at a local level. METHODS: We described how declining census response rates affected population data quality. We compared BAP and HSU data at district level. For the indicators 'access to primary care' and 'cervical cancer screening uptake' we replaced currently used BAP denominators with HSU and examined the impact for different ethnic groups in different geographic districts. RESULTS: Overall Census 2018 response declined by 10%, but for Maori and Pacific people by 21% and 23%, respectively. This inequitably affected BAP accuracy. Census undercount was highest in the district with the largest Pacific populations, where HSU exceeded BAP most. Notably, 'access to primary care' for Pacific people in this district consistently exceeds 100%. Using BAP, both health indicators are currently estimated as highest for Pacific people compared to other ethnic groups, but when based on HSU, they dropped to lowest. Similar, but less pronounced trends occurred in other districts. Changes in trends over time for both indicators coincided mostly with adjustments in BAP, rather than changes in the numerators. CONCLUSIONS: The current use of BAP denominators for health statistics does not enable reliable monitoring of key health indicators for Pacific people. HSU denominators are also unsuitable for monitoring health. Exploring the feasibility of a real-time population register is strongly recommended as a new, transparent, way of obtaining more reliable, timely population data to guide policymaking and underpin a more equitable health system under the health reforms. Meanwhile, reporting of ethnic specific outcomes need to include a clear assessment of the potential for bias due to inaccurate population estimates.

Sexually Transmitted Infections and the Risk of Reinfection Within 12 Months: A Population-Based Cohort.

BACKGROUND: Chlamydia, gonorrhea, and syphilis are common sexually transmitted infections that disproportionately affect specific groups in New Zealand (NZ). Predictors of reinfection are not well studied in NZ but could inform public health strategies to decrease sexually transmitted infection (STI) incidence. METHODS: New Zealand-wide chlamydia, gonorrhea, and syphilis cases during 2019 were identified using nationally collected data. Cases were followed-up to identify reinfection with the same STI within 12 months of initial infections. Logistic regression models were used to identify predictors for each STI reinfection. RESULTS: Determinants identified for increased odds of chlamydia reinfection were age groups 16-19 and 20-24 years, females, Maori and Pacific peoples, cases in the Northern region, and cases with at least one test before the initial infection. Age 40 years and older was associated with lower odds of gonorrhea reinfection, as was being of Asian ethnicity, living in Midland or Southern regions, and reporting heterosexual behavior. Region was the only statistically significant predictor for syphilis reinfection, with higher odds of reinfection for people living in the Central region. CONCLUSIONS: Our findings reflect disproportionate STI rates for some groups in NZ, with younger age groups, Maori and Pacific peoples, men who have sex with men, and people living in the Northern region experiencing higher odds of reinfection. Groups identified with higher odds for reinfection require increased access to culturally responsive health services to treat, understand, and prevent possible reinfection. Changes to current public health strategies could include culturally specific behavioral counseling, and improvements to and adherence to effective contract tracing.

Dengue, chikungunya and Zika virus infections among Dutch travellers to Suriname: a prospective study during the introduction of chikungunya and Zika virus, 2014 to 2017.

BackgroundSuriname, a country endemic for dengue virus (DENV), is a popular destination for Dutch travellers visiting friends and relatives and tourist travellers. Chikungunya and Zika virus (CHIKV, ZIKV) were introduced in 2014 and 2015, respectively. Data on infection risks among travellers are limited.AimWe aimed to prospectively study incidence rate (IR) and determinants for DENV, ZIKV and CHIKV infection in adult travellers to Suriname from 2014 through 2017.MethodsParticipants kept a travel diary and were tested for anti-DENV, anti-ZIKV and anti-CHIKV IgG antibodies (Euroimmun). Selected samples were subjected to an in-house DENV and ZIKV PRNT50. The IR (infections/1,000 person-months of travel) and IR ratio and determinants for infection were calculated.ResultsTravel-acquired infections were found in 21 of 481 participants: 18 DENV, four ZIKV and two CHIKV, yielding an IRDENV of 47.0 (95% CI: 29.6-74.6), IRZIKV of 11.6 (95% CI: 4.4-31.0) and IRCHIKV of 5.6 (95% CI: 1.4-22.2)/1,000 person-months. In nine DENV and three ZIKV infected participants, infections were PRNT50-confirmed, yielding a lower IRDENV of 23.3 (95% CI: 12.1-44.8) and an IRZIKV of 8.4 (95% CI: 2.7-26.1) per 1,000 person-months. Tourist travel was associated with DENV infection. ZIKV and CHIKV infections occurred soon after their reported introductions.ConclusionsDespite an overestimation of serologically confirmed infections, Dutch travellers to Suriname, especially tourists, are at substantial risk of DENV infection. As expected, the risk of contracting ZIKV and CHIKV was highest during outbreaks. Cross-reaction and potential cross-protection of anti-DENV and -ZIKV antibodies should be further explored.

Invasive Pneumococcal Disease: Concerning Trends in Serotype 19A Notifications in New Zealand.

New Zealand (NZ) is one of few countries to shift from PCV13 to PCV10. The number of serotype 19A cases in young children and the proportions of isolates that are penicillin-resistant have been steadily increasing since. It is time for NZ to reconsider its choice of pneumococcal vaccine.

Airborne Transmission of SARS-CoV-2 Delta Variant within Tightly Monitored Isolation Facility, New Zealand (Aotearoa).

In New Zealand, international arrivals are quarantined and undergo severe acute respiratory syndrome coronavirus 2 screening; those who test positive are transferred to a managed isolation facility (MIF). Solo traveler A and person E from a 5-person travel group (BCDEF) tested positive. After transfer to the MIF, person A and group BCDEF occupied rooms >2 meters apart across a corridor. Persons B, C, and D subsequently tested positive; viral sequences matched A and were distinct from E. The MIF was the only shared location of persons A and B, C, and D, and they had no direct contact. Security camera footage revealed 4 brief episodes of simultaneous door opening during person A's infectious period. This public health investigation demonstrates transmission from A to B, C, and D while in the MIF, with airborne transmission the most plausible explanation. These findings are of global importance for coronavirus disease public health interventions and infection control practices.

Population rates of HIV, gonorrhoea and syphilis diagnoses by sexual orientation in New Zealand.

INTRODUCTION: Globally, gay and bisexual men (GBM) are over-represented in HIV, syphilis and gonorrhoea cases. However, surveillance systems rarely provide meaningful measures of inequity, such as population-specific rates, due to a lack of sexual orientation denominators. HIV, gonorrhoea and syphilis are legally notifiable diseases in New Zealand (NZ); we calculate rates by sexual orientation for the first time. METHODS: We analysed 2019 national surveillance data on HIV, syphilis and gonorrhoea notifications disaggregated by sexual orientation. Unique health records identified duplicate notifications and reinfections. Missing data were imputed from known cases. We used the NZ Health Survey 2014/2015 to estimate population sizes by sexual orientation, measured in two ways (current sexual identity, sexual contact in the previous 12 months with men, women or both). We calculated notification rates per 100 000 for each sexual orientation subgroup and rate ratios. RESULTS: In 2019, GBM accounted for 76.3%, 65.7% and 39.4% of HIV, syphilis and gonorrhoea notifications, respectively. Population rates per 100 000 for HIV were 158.3 (gay/bisexual men) and 0.5 (heterosexuals); for syphilis, population rates per 100 000 were 1231.1 (gay/bisexual men), 5.0 (lesbian/bisexual women) and 7.6 (heterosexuals); for gonorrhoea (imputed), population rates per 100 000 were 6843.2 (gay/bisexual men), 225.1 (lesbian/bisexual women) and 120.9 (heterosexuals). The rate ratios for GBM compared with heterosexuals were: 348.3 (HIV); 162.7 (syphilis); and 56.6 (gonorrhoea). Inequities remained in sensitivity analysis (substituting sexual identity with sexual behaviour in the previous 12 months). CONCLUSION: GBM in NZ experience profound inequities in HIV, syphilis and gonorrhoea. Rate ratios by sexual orientation provide useful 'at-a-glance' measures of inequity in disease incidence.

Genomic Evidence of In-Flight Transmission of SARS-CoV-2 Despite Predeparture Testing.

Since the first wave of coronavirus disease in March 2020, citizens and permanent residents returning to New Zealand have been required to undergo managed isolation and quarantine (MIQ) for 14 days and mandatory testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As of October 20, 2020, of 62,698 arrivals, testing of persons in MIQ had identified 215 cases of SARS-CoV-2 infection. Among 86 passengers on a flight from Dubai, United Arab Emirates, that arrived in New Zealand on September 29, test results were positive for 7 persons in MIQ. These passengers originated from 5 different countries before a layover in Dubai; 5 had negative predeparture SARS-CoV-2 test results. To assess possible points of infection, we analyzed information about their journeys, disease progression, and virus genomic data. All 7 SARS-CoV-2 genomes were genetically identical, except for a single mutation in 1 sample. Despite predeparture testing, multiple instances of in-flight SARS-CoV-2 transmission are likely.

Frequent delayed spontaneous seroclearance of hepatitis B virus after incident HBV infection among adult high-risk groups.

High rates (~25%) of developing chronic hepatitis B virus (HBV) infection (hepatitis B surface antigen (HBsAg)-positive for > 6 months following infection) have been observed in people who use drugs (PWUD) and men who have sex with men (MSM). We aimed to estimate the frequency of delayed HBsAg seroclearance, along with its determinants, and time to delayed HBsAg seroclearance. Data were used from MSM and PWUD enrolled in the Amsterdam Cohort Studies (1985-2002) who had anti-hepatitis B core antibody seroconversion. Potential determinants for standard HBsAg seroclearance, delayed HBsAg seroclearance and chronic HBV were examined using multinominal logistic regression. Time to HBsAg seroclearance was estimated using Kaplan-Meier curves. A total of 147 incident HBV infections occurred during follow-up. On initial HBsAg testing after infection (6-12 months), 42 (29%) were HBsAg-positive and 105 (71%) were HBsAg-negative ('standard HBsAg seroclearance'). Of the 42 initially HBsAg-positive individuals, 22 subsequently tested HBsAg-negative (of whom 7 (31.8%) were HBV DNA positive at last visit, suggesting occult HBV). Overall, 15 became HBsAg-negative and HBV DNA-negative ('delayed HBsAg seroclearance'), while 27 remained HBsAg and/or HBV DNA-positive ('chronic HBV'). The 5-year cumulative probability of delayed HBsAg seroclearance was 41.6% for initially HBsAg-positive individuals. Delayed HBsAg seroclearance and remaining chronically infected were associated with younger age and HIV/hepatitis C virus (HCV)-co-infection. In conclusion, delayed HBsAg seroclearance is common in these key adult populations at-risk for HBV, while proportion developing HBV chronicity (18%) is still higher compared to the general population (~5%). Given the proportion of individuals with occult HBV infection and that HCV direct-acting antivirals can lead to HBV reactivation, HBV DNA testing in HCV co-infected MSM/PWUD are warranted prior to treatment initiation.

No chikungunya virus infections among Dutch long-term travellers to (sub)tropical countries: a prospective study 2008-2011.

BACKGROUND: Chikungunya is an arthropod-borne viral disease now identified in over 60 countries in Asia, Africa, Europe, and the Americas. Chikungunya virus (CHIKV) has spread in the last 15 years to many countries, causing large local outbreaks. CHIKV infection can be clinically misdiagnosed in areas where dengue and/or Zika infections occur. Prospective studies are necessary to calculate the true incidence rate of CHIKV infection in travellers. The aim of this study was to obtain the attack and incidence rates of CHIKV infection among long-term travellers and identify associated risk factors. METHODS: A previously collected prospective cohort of Dutch long-term travellers (12-52 weeks) to subtropical and tropical countries was tested. From December 2008 to September 2011, participants were recruited at the travel clinic of the Public Health Service Amsterdam. A weekly diary was kept during travel in which participants recorded their itinerary, symptoms, and physician visits. On return, their pre- and post-travel blood samples were tested for the presence of IgG antibodies to CHIKV antigen. Seroconversions were confirmed by an in-house CHIKV neutralisation test. RESULTS: The median age of 603 participants was 25 years (interquartile range [IQR]: 23-29); 35.7% were male; median travel duration was 20 weeks (IQR: 15-25), and purpose of travel was predominantly tourism (62%). The presence of anti-CHIKV IgG in the pre-travel sample, suggestive of previous CHIKV infection, was found for 3/603 participants (0.5%); all three had been previously travelling in either Africa or Asia. In one traveler who visited Latin America, a seroconversion was found (0.2%) but the CHIKV neutralisation test was negative, making the incidence rate 0. CONCLUSION: No chikungunya virus infections were found in this 2008-2011 prospective cohort of long-term travellers. We recommend the research be repeated, particularly as the sample size of our cohort might have been too small. Also, extensive spread of chikungunya virus has likely increased incidence rates among travellers since 2013.

Hepatitis E in Long-Term Travelers from the Netherlands to Subtropical and Tropical Countries, 2008-2011.

Hepatitis E virus (HEV) is a common cause of acute viral hepatitis. Virus genotypes 1 and 2 infect humans in developing countries by the fecal-oral route. To assess attack rates and disease incidence for travelers, we prospectively studied 604 long-term travelers to subtropical and tropical countries. Participants donated blood samples pretravel and posttravel and kept a diary. A total of 89/604 (15%) pretravel samples were positive for HEV IgG by ELISA, suggesting previous HEV infection. Seroconversion for HEV was found for 19/515 travelers (attack rate 3.7%, incidence 1.8 cases/1,000 person-weeks). We believe there is a substantial risk for acquiring HEV infection among long-term travelers. Although HEV infection does not seem to be a major problem in this healthy cohort, hygienic measures should be stressed in all pretravel health advice, particularly for pregnant women and immunocompromised travelers who are at risk for severe disease.

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) among travellers to Africa: destination-specific data pooled from three European prospective studies.

BACKGROUND: One third of travellers to low- and middle-income regions of the tropics and subtropics become colonized by extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE). The risk varies by destination and, for each traveller, may be substantially further increased by travellers' diarrhoea (TD) and antibiotic use. Despite the risk of TD in Africa, ESBL-PE acquisition rates in all studies are lower there than in Asia. Africa has become increasingly popular as a destination for international travellers, yet minimal data are available from the continent's subregions and countries. METHODS: We analysed subregion- and country-specific data on carriage and risk factors for ESBL-PE colonization pooled from three prospective studies conducted between 2009 and 2013 among Finnish and Dutch travellers. The data were subjected to multivariable analysis of risk factors. In addition, we compared our data to two recent large investigations reporting data by subregion and country. RESULTS: Our joint analysis comprised data on 396 travellers. The ESBL-PE colonization rate was highest in Northern Africa, followed by Middle and Eastern Africa, and lowest in Southern and Western Africa. Of individual countries with more than 15 visitors, the highest rates were seen for Egypt (12/17; 70.6%), Ghana (6/23; 26.1%), and Tanzania (14/81; 17.3%); the rates among travellers to Egypt were comparable to those reported in South and Southeast Asia. In a pooled multivariable analysis, travel destination, age, overnight hospitalisation abroad, TD, and use of fluoroquinolones were independently associated with increased ESBL-PE colonization rates. CONLUSIONS: Even in areas with relatively low risk of colonization, antimicrobials clearly predispose to colonization with ESBL-PE. Travellers to Africa should be cautioned against unnecessary use of antibiotics.

Spillover of a hepatitis A outbreak among men who have sex with men (MSM) to the general population, the Netherlands, 2017.

Since 2015, outbreaks of hepatitis A among men who have sex with men (MSM) have been reported worldwide. To examine the impact of these MSM outbreaks in the Netherlands, we combined notification and epidemiological data with sequence analysis. Our results show the hazards of outbreaks within risk-groups spilling over into the largely susceptible general population. One third of the outbreak-related hepatitis A virus genotypes were detected in non-MSM cases.

Integrating hepatitis B, hepatitis C and HIV screening into tuberculosis entry screening for migrants in the Netherlands, 2013 to 2015.

We evaluated uptake and diagnostic outcomes of voluntary hepatitis B (HBV) and C virus (HCV) screening offered during routine tuberculosis entry screening to migrants in Gelderland and Amsterdam, the Netherlands, between 2013 and 2015. In Amsterdam, HIV screening was also offered. Overall, 54% (461/859) accepted screening. Prevalence of chronic HBV infection (HBsAg-positive) and HCV exposure (anti-HCV-positive) in Gelderland was 4.48% (9/201; 95% confidence interval (CI): 2.37-8.29) and 0.99% (2/203; 95% CI: 0.27-3.52), respectively, all infections were newly diagnosed. Prevalence of chronic HBV infection, HCV exposure and chronic HCV infection (HCV RNA-positive) in Amsterdam was 0.39% (1/256; 95% CI: 0.07-2.18), 1.17% (3/256; 95% CI: 0.40-3.39) and 0.39% (1/256; 95% CI: 0.07-2.18), respectively, with all chronic HBV/HCV infections previously diagnosed. No HIV infections were found. In univariate analyses, newly diagnosed chronic HBV infection was more likely in participants migrating for reasons other than work or study (4.35% vs 0.83%; odds ratio (OR) = 5.45; 95% CI: 1.12-26.60) and was less likely in participants in Amsterdam than Gelderland (0.00% vs 4.48%; OR = 0.04; 95% CI: 0.00-0.69). Regional differences in HBV prevalence might be explained by differences in the populations entering compulsory tuberculosis screening. Prescreening selection of migrants based on risk factors merits further exploration.

Determinants of Human Papillomavirus Vaccination Intention Among Female Sex Workers in Amsterdam, the Netherlands.

INTRODUCTION: Female sex workers (FSWs) are at risk for human papillomavirus (HPV)-induced diseases but are currently not targeted by the HPV vaccination program in the Netherlands. We explored determinants of their intention to get vaccinated against HPV in case vaccination would be offered to them. METHODS: In 2016, FSWs 18 years and older having a sexually transmitted infection consultation with the Prostitution & Health Center (P&G292) in Amsterdam, either at the clinic or at their working location, were invited to complete a questionnaire assessing sociopsychological determinants of HPV vaccination intention (scale ranging from -3 to +3). Determinants of HPV vaccination intention were assessed with univariable and multivariable linear regression. In addition, we explored the effect of out-of-pocket payment on intention. RESULTS: Between May and September 2016, 294 FSWs participated. The median age was 29 years (interquartile range, 25-37 years). Human papillomavirus vaccination intention was high (mean, 2.0; 95% confidence interval [CI], 1.8-2.2). In multivariable analysis, attitude (ß = 0.6; 95% CI, 0.5-0.7), descriptive norm (ß = 0.2; 95% CI, 0.1-0.3), self-efficacy (ß = 0.2; 95% CI, 0.1-0.3), beliefs (ß = 0.1; 95% CI, 0.0-0.2), and subjective norm (ß = 0.1; 95% CI, 0.0-0.2) seemed to be the strongest predictors of HPV vaccination intention (R = 0.54). Human papillomavirus vaccination intention decreased significantly to a mean of 0.2 when vaccination would require out-of-pocket payment of &OV0556;350. CONCLUSIONS: The HPV vaccination intention among FSWs seems relatively high and is most strongly constituted in attitudinal, normative, and self-efficacy beliefs. Out-of-pocket payment will probably have a negative impact on their HPV vaccination acceptability.

Increase in imported malaria in the Netherlands in asylum seekers and VFR travellers.

BACKGROUND: Malaria is a notifiable disease in the Netherlands, a non-endemic country. Imported malaria infections occur regularly among travellers, migrants and visitors. Surveillance data were analysed from 2008 to 2015. Trends in amounts of notifications among risk groups were analysed using Poisson regression. For asylum seekers, yearly incidence was calculated per region of origin, using national asylum request statistics as denominator data. For tourists, denominator data were used from travel statistics to estimate incidence per travel region up to 2012. RESULTS: A modest increase in overall imported malaria notifications occurred in 2008-2015 (from 222 in 2008 to 344 in 2015). Notably, in 2014 and 2015 sharp increases were seen in malaria among travellers visiting friends and relatives (VFR), and in asylum seekers. Of all Plasmodium falciparum infections, most (1254/1337; 93.8%) were imported from Africa; 1037/1337 (77.6%) were imported from Central and West Africa. Malaria in VFR was mostly caused by P. falciparum infection after visiting Ghana (22%) or Nigeria (19%). Malaria in asylum seekers was mostly caused by Plasmodium vivax infection from the Horn of Africa. The large number of notifications in asylum seekers resulted from both an increase in number of asylum seekers and a striking increase of malaria incidence in this group. Incidence of malaria in asylum seekers from the Horn of Africa ranged between 0.02 and 0.3% in 2008-2013, but rose to 1.6% in 2014 and 1.3% in 2015. In 2008-2012, incidence in tourists visiting Central and West Africa dropped markedly. CONCLUSIONS: Imported malaria is on the rise again in the Netherlands, most notably since 2013. This is mostly due to immigration of asylum seekers from the Horn of Africa. The predominance of P. vivax infection among asylum seekers warrants vigilance in health workers when a migrant presents with fever, as relapses of this type of malaria can occur long after arrival in the Netherlands.

Hepatitis A outbreak among men who have sex with men (MSM) predominantly linked with the EuroPride, the Netherlands, July 2016 to February 2017.

Between July 2016 and February 2017, 48 male cases of hepatitis A were notified in the Netherlands. Of these, 17 identified as men who have sex with men (MSM). Ten of the 13 cases for whom sequencing information was available, were infected with a strain linked with the EuroPride that took place in Amsterdam in 2016. This strain is identical to a strain that has been causing a large outbreak among MSM in Taiwan.

Influenza in long-term Dutch travelers in the tropics: symptoms and infections.

BACKGROUND: Influenza is a common infection among travelers, and attack rates are well documented in short-term travelers and holiday makers. Little data exists on long-term, non-expatriate travelers. METHODS: This was a prospective mono-centre study of immunocompetent, Dutch travelers aged ≥18 to 64 years. It was conducted at the Public Health Service travel clinic in Amsterdam from December 2008 to September 2011, and included all travelers intending to travel to a tropical or sub-tropical country. RESULTS: Among 602 Dutch long-term travelers to tropical regions, 82 % had protective influenza antibody titres pre-travel. The influenza attack rate of serologically confirmed infection during travel was 15 %, and of symptomatic infection was 6.3 % (fever alone) and 2 % (ILI), respectively. CONCLUSIONS: The attack rate in this study is similar to seasonal rates of infection in the general population. Influenza vaccination pre-travel is therefore most important for people at risk of medical complications due to influenza.

Travel-related MERS-CoV cases: an assessment of exposures and risk factors in a group of Dutch travellers returning from the Kingdom of Saudi Arabia, May 2014.

BACKGROUND: In May 2014, Middle East respiratory syndrome coronavirus (MERS-CoV) infection, with closely related viral genomes, was diagnosed in two Dutch residents, returning from a pilgrimage to Medina and Mecca, Kingdom of Saudi Arabia (KSA). These patients travelled with a group of 29 other Dutch travellers. We conducted an epidemiological assessment of the travel group to identify likely source(s) of infection and presence of potential risk factors. METHODS: All travellers, including the two cases, completed a questionnaire focussing on potential human, animal and food exposures to MERS-CoV. The questionnaire was modified from the WHO MERS-CoV questionnaire, taking into account the specific route and activities of the travel group. RESULTS: Twelve non-cases drank unpasteurized camel milk and had contact with camels. Most travellers, including one of the two patients (Case 1), visited local markets, where six of them consumed fruits. Two travellers, including Case 1, were exposed to coughing patients when visiting a hospital in Medina. Four travellers, including Case 1, visited two hospitals in Mecca. All travellers had been in contact with Case 1 while he was sick, with initially non-respiratory complaints. The cases were found to be older than the other travellers and both had co-morbidities. CONCLUSIONS: This epidemiological study revealed the complexity of MERS-CoV outbreak investigations with multiple potential exposures to MERS-CoV reported such as healthcare visits, camel exposure, and exposure to untreated food products. Exposure to MERS-CoV during a hospital visit is considered a likely source of infection for Case 1 but not for Case 2. For Case 2, the most likely source could not be determined. Exposure to MERS-CoV via direct contact with animals or dairy products seems unlikely for the two Dutch cases. Furthermore, exposure to a common but still unidentified source cannot be ruled out. More comprehensive research into sources of infection in the Arabian Peninsula is needed to strengthen and specify the prevention of MERS-CoV infections.

Screening travellers to high-endemic countries for infection with Mycobacterium tuberculosis using interferon gamma release assay; a prospective study.

BACKGROUND: International travel from low-incidence to high-incidence countries for tuberculosis (TB) is regarded as a risk factor for acquiring TB infection. In this prospective study among long-term travellers we examined the incidence of TB infection using Interferon gamma release assay (IGRA) test and compared these data with results from a visit to the TB department to which all long-term travellers were routinely referred. METHODS: Immunocompetent adults, travelling for 13-52 weeks to TB-endemic countries, donated blood pre- and post-travel for IGRA. The pre-travel IGRA was only tested in case of a positive IGRA post-travel. Results from their visit(s) to the TB department for TST pre- and post-travel were collected and compared with study results. RESULTS: We found two IGRA conversions in a group of 516 travellers, resulting in an attack rate (AR) of 0.4% (95% CI: 0.5 - 13.9) and an incidence rate (IR) of 0.85 per 1000 person-months (95% CI: 0.1-3.1).We found 5 tuberculin skin test (TST) conversions, resulting in AR of 1.9% (5/261; 95% CI: 0.6 - 4.4) and an IR of 4.26 per 1000 person-months (95% CI: 1.38- 9.94). In our study these converters all had a negative IGRA. One traveller however, who was retested later at the TB department due to a positive TST, then appeared to have seroconverted. CONCLUSIONS: The risk of long-term travellers among our study population acquiring TB infection is low. We conclude that post-travel IGRA alone could be used for screening for TB infection among long-term travellers to high-endemic TB countries, but preferably not earlier than 8 weeks after return. One might even argue that IGRA testing should be limited to only those travellers who are going to work in a medical setting. A person with a positive IGRA should be referred to a TB physician for further evaluation.