Vaccine coverage among children born to immigrant parents in Norway, 2000-2020

BACKGROUND

The Norwegian Childhood Immunization Program maintains a high national coverage of 95-97% in the most recent years. Whether there are subgroups with lower uptake is less studied. This study examines pertussis and measles vaccination coverage among six immigrant groups in Norway. These vaccines are normally administered as part of different combination vaccines and their coverage rate indicate the national vaccination coverage against a range of additional infections.

METHODS

Data from the Norwegian National Population Register were linked at individual level with vaccination data from the Norwegian Immunisation Registry. The final sample consisted of 53,052 children born during 2000-2018 in Norway to parents who were born in Iraq, Lithuania, Pakistan, Poland, Somalia, or Vietnam. Vaccination coverage was measured at 2-years of age. Multivariate linear regression was utilized to estimate the relationship between vaccinations status, year of birth, gender, mother's length of residency in Norway, and area of residence.

RESULTS

At two years of age, the majority of the children were vaccinated. Coverage among the groups varied at, above, and below the national average for the two vaccines. For most of the years examined, children born by parents from Lithuania, Poland, and Somalia had lower coverage for the measles vaccine (range 81-84% in 2020) than the national level (97% in 2020). Children born by parents from the Eastern-European countries also had lower coverage than the national level for the pertussis vaccine (range 87-89% in 2020).

DISCUSSION

This study illustrates how subgroups with lower vaccination coverage may exists within a well-established vaccination program with high national coverages. Differences in coverage were found for both vaccines, but the differences were more pronounced for the measles vaccine. The high vaccination coverage in Norway provides indirect protection through herd immunity for unvaccinated individuals, however, the lower vaccination coverage in some immigrant groups is a concern.

Vaksinasjonsdekning mot covid-19 etter fødeland og underliggende risiko for alvorlig sykdomsforløp

Background

Support for the COVID-19 vaccination programme has been high in Norway throughout the pandemic, but previous studies have observed variation based on country of birth. If the unvaccinated are young and healthy, the risk and consequences for the individual and for the health service will be less than if the unvaccinated have underlying risk of severe COVID-19. The purpose of the study was to examine the degree to which vaccination coverage varied by country of birth in persons with and without underlying risk.

Material and method

We used the Norwegian emergency preparedness register Beredt C19 to link vaccination coverage to demographic and health variables. Using Poisson regression, we estimated the relative likelihood of being vaccinated for foreign-born individuals compared to Norwegian-born individuals, for those with and without underlying risk of severe COVID-19, adjusted for sex, age, level of education, household income and county.

Results

The study population was 4 304 249, which included 768 312 people who were born outside Norway. The vaccination coverage varied in total from 47 to 94 % between countries of birth. The variation between countries of birth was less in the group with underlying risk, ranging from 63 to 96 %. The difference between persons with and without an underlying risk was most pronounced among those born in Poland (RR 0.71 and 0.55) and Lithuania (RR 0.69 and 0.61). In absolute numbers, this corresponded to a difference in relative risk of 0.16 and 0.08, respectively.

Interpretation

Higher vaccination coverage against COVID-19 among persons with an underlying risk means that the variation between countries of birth may have had less serious implications in terms of severe clinical course and healthcare needs than previously assumed.

Prevalence and incidence of symptomatic pulmonary tuberculosis based on repeated population screening in a district in Ethiopia: a prospective cohort study

OBJECTIVE

In Ethiopia, one-third of the estimated tuberculosis cases are not detected or reported. Incidence estimates are inaccurate and rarely measured directly. Assessing the 'real' incidence under programme conditions is useful to understand the situation. This study aimed to measure the prevalence and incidence of symptomatic pulmonary tuberculosis (PTB) during 1 year in the adult population of Dale in Ethiopia.

DESIGN

A prospective population-based cohort study.

SETTING

Every household in Dale was visited three times at 4-month intervals.

PARTICIPANTS

Individuals aged ≥15 years.

OUTCOME MEASURES

Microscopy smear positive PTB (PTB s+), bacteriologically confirmed PTB (PTB b+) by microscopy, GeneXpert, or culture and clinically diagnosed PTB (PTB c+).

RESULTS

Among 136 181 individuals, 2052 had presumptive TB (persistent cough for 14 days or more with or without haemoptysis, weight loss, fever, night sweats, chest pain or difficulty breathing), in the first round of household visits including 93 with PTB s+, 98 with PTB b+ and 24 with PTB c+; adding those with PTB who were already on treatment, the total number of PTB was 201, and the prevalence was 147 (95% CI: 127 to 168)/100 000 population. Out of all patients with PTB, the proportion detected by symptom screening was in PTB s+ 65%, PTB b+ 67% and PTB c+44%. During 96 388 person-years follow-up, 1909 had presumptive TB, 320 had PTB and the total incidence of PTB was 332 (95% CI: 297 to 370)/100 000 person-years, while the incidence of PTB s+, PTB b+ and PTB c+ was 230 (95% CI: 201 to 262), 263 (95% CI: 232 to 297) and 68 (95% CI: 53 to 86)/100 000 person-years, respectively.

CONCLUSION

The prevalence of symptomatic sputum smear-positive TB was still high, only one-third of prevalent PTB cases notified and the incidence rate highest in the age group 25-34 years, indicating ongoing transmission. Finding missing people with TB through repeated symptom screening can contribute to reducing transmission.

Vaksineusikkerhet blant innvandrere under covid-19-pandemien – en kvalitativ studie

BACKGROUND

Vaccination against SARS-CoV-2 has been an important measure in dealing with the pandemic. In Norway, vaccination coverage has been lower in several immigrant groups than in the general population. The aim of this study was to investigate which factors may have played a role in the low uptake rate among immigrants.

MATERIAL AND METHOD

Eighty-eight semi-structured, qualitative interviews were conducted remotely in the period March to June 2021. The interviewees consisted of 49 women and 39 men aged 19-78, from ten different countries. In a thematic analysis (NVivo-12), four main categories relating to vaccine hesitancy emerged: system-based factors, factors linked to personal conviction, factors linked to fear and factors linked to trust.

RESULTS

Although many of the informants were willing to take the vaccine, several expressed vaccine hesitancy. Lack of evidence-based information and fear of adverse effects were cited as reasons. Vaccine hesitancy was also linked to misinformation and conspiracy theories. Some had no confidence in the vaccination programme or the efficacy of the vaccine.

INTERPRETATION

The study revealed that vaccine hesitancy among immigrants was due to a range of factors. The main reasons included lack of information, low health literacy, insufficient knowledge of how the vaccine works, and little trust in the authorities.

Cost-utility analysis of the universal pneumococcal vaccination programme for older adults in Norway

The aim of this study was to establish whether the universal pneumococcal vaccination for older adults in Norway is likely to be cost-effective from the perspective of the health care provider. A decision tree model developed by the Public Health Agency of Sweden was adapted to the Norwegian setting. Two cohorts, consisting of 65-year-olds and 75-year-olds grouped into vaccinated and unvaccinated, were followed over a 5-year time horizon. In the base case, the 23-valent polysaccharide vaccine (PPV23) was used while the 13-valent pneumococcal conjugate vaccine (PCV13) was included in scenario analyses only. The costs and health benefits (measured in quality adjusted life years (QALY) gained) were compared in the two cohorts between the vaccinated and unvaccinated groups. The impact of indirect effects of the vaccine, such as herd immunity and serotype replacement, were not investigated. The relative importance of change in price was assessed by performing one-way sensitivity analyses. Under base-case assumptions, the programme for the 75-year-old cohort is expected to be dominant (cost-effective) from the health care perspective at the current maximal pharmacy retail price and at 75% vaccination coverage. In comparison, for the 65-year-old cohort the cost per QALY gained is approximately NOK 601,784 (EUR 61,281) under the base-case assumptions. A reduction in the cost of the vaccine to one quarter of its current level also brings the cost per QALY gained within the acceptable ranges in a Norwegian context for both the 65- and 75-year-old cohorts. There is no exact cost-effectiveness threshold in Norway. However, introducing a vaccination programme against pneumococcal disease for 65-year-olds in Norway is likely to fall within the acceptable range while for the 75-year-old cohort the universal programme appears to be dominant (cost-effective).

How many of persistent coughers have pulmonary tuberculosis? Population-based cohort study in Ethiopia

OBJECTIVE

Many individuals with persistent cough and smear microscopy-negative sputum test for tuberculosis (TB) remain at risk of developing the disease. This study estimates the incidence of pulmonary TB (PTB) among initially smear-negative persistent coughers and its risk factors.

DESIGN

A prospective population-based follow-up study.

SETTING

Health extension workers visited all households in Dale woreda three times at 4-month intervals in 2016-2017 to identify individuals with symptoms compatible with TB (presumptive TB) using pretested and semistructured questionnaires.

PARTICIPANTS

We followed 3484 presumptive TB cases (≥15 years) with an initial smear-negative TB (PTB) test.

OUTCOME MEASURES

Bacteriologically confirmed PTB (PTB b+) and clinically diagnosed PTB (PTB c+).

RESULTS

3484 persons with initially smear-negative presumptive PTB were followed for 2155 person-years (median 0.8 years); 90 individuals had PTB b+ and 90 had PTB c+. The incidence rates for PTB b+ and PTB c+ were both 4176 (95% CI 3378 to 5109) per 100 000 person-years. We used penalised (lasso) and non-penalised proportional hazards Cox regression models containing all exposures and outcomes to explore associations between exposures and outcomes. In lasso regression, the risk of development of PTB b+ was 63% (HR 0.37) lower for people aged 35-64 years and 77% (HR 0.23) lower for those aged ≥65 years compared with 15-34 year-olds. Men had a 62% (HR 1.62) greater risk of PTB b+ development than women. The risk of PTB c+ was 39% (HR 0.61) lower for people aged 35-54 years than for those aged 15-34 years. Men had a 56% (HR 1.56) greater risk of PTB c+ development than women.

CONCLUSIONS

PTB incidence rate among persistent coughers was high, especially among men and young adults, the latter signifying sustained transmission. Awareness about this among healthcare workers may improve identification of more new TB cases.

Estimation of the incidence of hospitalization for non-invasive pneumococcal pneumonia in the Norwegian population aged 50 years and older

The purpose of this study was to estimate simple measures of the burden of non-invasive pneumococcal pneumonia (PnPn) hospitalisations in those aged 50 years and older (50+) in Norway. We conducted a retrospective register-based study and used discharge codes from the Norwegian Patient Register (NPR). We identified episodes of non-invasive PnPn in 2015 to 2016 and predicted its incidence from 2015 to 2019 based on the trend found in notified invasive pneumococcal disease cases. Overall, we identified 45–46 hospital episodes per 100 000 population of non-invasive PnPn in 2015 and 2016, each episode taking 6–8 days, and with increasing incidence with higher age. Among all identified PnPn episodes, 3 out of 4 were classified as non-invasive. We predicted that the monthly number of non-invasive PnPn episodes ranges from 39 [95% confidence interval (CI) 24–55] in August to 97 (95% CI 74–134) in December. No annual trend was identified. This study indicates that the burden of non-invasive PnPn hospitalisation has a substantial impact on the health and health care use of the 50+ population in Norway, despite the childhood immunisation programme. Many hospitalisations may be prevented through vaccination.

Seroprevalence of antibodies against SARS-CoV-2 in the adult population during the pre-vaccination period, Norway, winter 2020/21

BackgroundSince March 2020, 440 million people worldwide have been diagnosed with COVID-19, but the true number of infections with SARS-CoV-2 is higher. SARS-CoV-2 antibody seroprevalence can add crucial epidemiological information about population infection dynamics.AimTo provide a large population-based SARS-CoV-2 seroprevalence survey from Norway; we estimated SARS-CoV-2 seroprevalence before introduction of vaccines and described its distribution across demographic groups.MethodsIn this population-based cross-sectional study, a total of 110,000 people aged 16 years or older were randomly selected during November-December 2020 and invited to complete a questionnaire and provide a dried blood spot (DBS) sample.ResultsThe response rate was 30% (31,458/104,637); compliance rate for return of DBS samples was 88% (27,700/31,458). National weighted and adjusted seroprevalence was 0.9% (95% CI (confidence interval): 0.7-1.0). Seroprevalence was highest among those aged 16-19 years (1.9%; 95% CI: 0.9-2.9), those born outside the Nordic countries 1.4% (95% CI: 1.0-1.9), and in the counties of Oslo 1.7% (95% CI: 1.2-2.2) and Vestland 1.4% (95% CI: 0.9-1.8). The ratio of SARS-CoV-2 seroprevalence (0.9%) to cumulative incidence of virologically detected cases by mid-December 2020 (0.8%) was slightly above one. SARS-CoV-2 seroprevalence was low before introduction of vaccines in Norway and was comparable to virologically detected cases, indicating that most cases in the first 10 months of the pandemic were detected.ConclusionFindings suggest that preventive measures including contact tracing have been effective, people complied with physical distancing recommendations, and local efforts to contain outbreaks have been essential.

Using qualitative research to develop an elaboration of the TIDieR checklist for interventions to enhance vaccination communication: short report

Background

The COVID-19 pandemic has led to an increased interest in communication with the public regarding vaccination. Our recent Cochrane qualitative evidence synthesis points to several factors that could influence the implementation and success of healthcare worker communication with older adults about vaccination. However, it is often difficult to assess whether factors identified as potentially important in qualitative studies have been considered in randomized trials because of poor trial reporting. We therefore decided to use our qualitative evidence synthesis findings to encourage better reporting of vaccination communication interventions in trials by developing an elaboration of the TIDieR (Template for Intervention Description and Replication) checklist for intervention reporting.

Methods

We examined the findings from our Cochrane qualitative evidence synthesis on healthcare workers’ perceptions of and experiences with communicating about vaccination with adults over the age of 50 years. We identified factors that could influence the implementation and uptake, and thereby the effectiveness, of vaccination communication interventions. We then drafted a list of the information elements we would need from trial reports to assess whether these factors had been considered in the development of the interventions evaluated in these trials. Finally, we compared our list of information elements to the TIDieR checklist items. We were able to align all of our information elements with the TIDieR items. However, for several of the TIDieR items, we developed a more detailed description to ensure that relevant information would be captured sufficiently in trial reports.

Results

We developed elaborations for the following TIDieR items: “Why” (item 2), “What—materials” (item 3), “Who provided” (item 5), “How” (item 6), “Where” (item 7) and “Tailoring” (item 9).

Conclusions

Both qualitative research and trials of intervention effectiveness are critical to furthering our understanding of what works, where, for whom and through which mechanisms. However, a key ingredient for developing this understanding is adequate reporting of intervention design, content and implementation in randomized trials. We hope that this elaboration of the TIDier checklist will improve reporting of interventions in trials focused on vaccine communication with older adults, and thereby enhance the usability of this research for developing future communication strategies.

Comprehensive Contact Tracing, Testing and Sequencing Show Limited Transmission of SARS-CoV-2 between Children in Schools in Norway, August 2020 to May 2021

The role of children in the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in schools has been a topic of controversy. In this study among school contacts of SARS-CoV-2 positive children in 43 contact-investigations, we investigated SARS-CoV-2 transmission in Norway, August 2020-May 2021. All participants were tested twice within seven to ten days, using SARS-CoV-2 PCR on home-sampled saliva. Positive samples were whole genome sequenced. Among the 559 child contacts, eight tested positive (1.4%, 95% CI 0.62-2.80), with no significant difference between primary (1.0%, 95% CI 0.27-2.53) and secondary schools (2.6%, 95% CI 0.70-6.39), p = 0.229, nor by viral strain, non-Alpha (1.4%, 95% CI 0.50-2.94) and Alpha variant (B.1.1.7) (1.7%, 95% CI 0.21-5.99), p = 0.665. One adult contact (1/100) tested positive. In 34 index cases, we detected 13 different SARS-CoV-2 Pango lineage variants, with B.1.1.7 being most frequent. In the eight contact-investigations with SARS-CoV-2 positive contacts, four had the same sequence identity as the index, one had no relation, and three were inconclusive. With mitigation measures in place, the spread of SARS-CoV-2 from children in schools is limited. By excluding contact-investigations with adult cases known at the time of enrolment, our data provide a valid estimate on the role of children in the transmission of SARS-CoV-2 in schools.

Sociodemographic determinants of catch-up HPV vaccination completion between 2016-2019 in Norway

Between 2016 and 2019, a catch-up human papillomavirus (HPV) vaccination took place in Norway for women born between 1991 and 1996. The aim of this study was to identify sociodemographic determinants of complete vaccination (3 doses) and partial vaccination (1–2 doses). A random sample of 10,000 women who were offered catch-up HPV vaccination were invited. We assessed the association between sociodemographic characteristics and vaccination completion using univariable and multivariable multinomial logistic regression.

Of 4,967 respondents, 3,464 (63%) received complete vaccination and 298 (7%) received partial vaccination. 30% did not receive any vaccination and functioned as reference group. Compared with having Norwegian caregivers, having a caregiver from non-western countries decreased the odds of partial and complete vaccination (aOR = 0.57; 95%CI = 0.35–0.95 and aOR = 0.57; 95%CI = 0.44–0.74). Having a caregiver from other western countries decreased the odds of complete vaccination (aOR = 0.72; 95%CI = 0.52–0.98). Residing in Norway for 10 years or longer significantly increased the odds of complete vaccination (aOR = 2.65; 95%CI = 1.58–4.43). Being in a relationship significantly increased the odds of partial vaccination compared with being single (aOR = 1.50; 95%CI = 1.02–2.21). Being married (aOR = 0.66; 95%CI = 0.50–0.86) and having children (aOR = 0.53; 95%CI = 0.42–0.68) decreased the odds of complete vaccination. Having university education increased the odds of both partial and complete vaccination (aOR = 2.19; 95%CI = 1.47–3.25 and aOR = 4.11; 95%CI = 3.33–5.06).

Having a caregiver born outside of Norway, having children and being married decreased the odds of receiving complete HPV vaccination. This highlights the need to target communication around HPV vaccination toward different ethnic communities and include more specific messaging that having children and being married does not necessarily prevent HPV infections.

Easy access to vaccination was important for adherence during the 2016-2019 HPV catch-up vaccination in Norway

Between September and October 2019, the Norwegian Institute for Public Health (NIPH) surveyed women born between 1991 and 1996 who were offered catch-up vaccination for human papilloma virus (HPV). The aim was to identify determinants of vaccine schedule adherence. A random sample of 10,000 women who were offered catch-up vaccination were invited to participate in the survey. We defined adherence as receiving all three doses. Determinants of HPV vaccination adherence were investigated using descriptive, univariable and multivariable logistic regression analyses providing adjusted odds ratios (aOR). Data from 3,762 respondents who received at least one dose were included. Overall, 92.1% (95% CI = 89.3-91.9) of those initiating vaccination adhered to the complete schedule. The following factors were significantly associated with HPV vaccination adherence compared to non-adherence: country of origin (aOR = 0.43; 95% CI = 0.47-0.97), having children (aOR = 0.51; 95% CI = 0.35-0.73), ease of finding out where to get vaccinated (aOR = 1.94; 95% CI = 1.69-2.23), preference for receiving information from health authorities (aOR = 1.37; 95% CI = 1.04-1.81) and vaccination being readily available (aOR = 2.28; 95% CI = 1.50-3.37). Information from NIPH via SMS and social media were negatively associated for Norwegians (aOR = 0.68, 95% CI = 0.46-1.01) and positively associated for those whose country of origin was not Norway (aOR = 1.48, 95% CI = 0.69-3.14; not significant). Those who did not adhere to the full vaccination schedule reported that they had forgotten (40.4%; 95% CI = 33.5-47.8) or had no time (32.9%; 95% CI = 26.2-40.4). Despite NIPH's targeted communication campaign, the main barriers for HPV vaccination adherence were difficulty to find out where to get the vaccine, forgetting to take the vaccine or not having time to complete the schedule.

Healthcare workers' perceptions and experiences of communicating with people over 50 years of age about vaccination: a qualitative evidence synthesis

BACKGROUND

Infectious diseases are a major cause of illness and death among older adults. Vaccines can prevent infectious diseases, including against seasonal influenza, pneumococcal diseases, herpes zoster and COVID-19. However, the uptake of vaccination among older adults varies across settings and groups. Communication with healthcare workers can play an important role in older people's decisions to vaccinate. To support an informed decision about vaccination, healthcare workers should be able to identify the older person's knowledge gaps, needs and concerns. They should also be able to share and discuss information about the person's disease risk and disease severity; the vaccine's effectiveness and safety; and practical information about how the person can access vaccines. Therefore, healthcare workers need good communication skills and to actively keep up-to-date with the latest evidence. An understanding of their perceptions and experiences of this communication can help us train and support healthcare workers and design good communication strategies.

OBJECTIVES

To explore healthcare workers' perceptions and experiences of communicating with older adults about vaccination.

SEARCH METHODS

We searched MEDLINE, CINAHL and Scopus on 21 March 2020. We also searched Epistemonikos for related reviews, searched grey literature sources, and carried out reference checking and citation searching to identify additional studies. We searched for studies in any language.

SELECTION CRITERIA

We included qualitative studies and mixed-methods studies with an identifiable qualitative component. We included studies that explored the perceptions and experiences of healthcare workers and other health system staff towards communication with adults over the age of 50 years or their informal caregivers about vaccination.

DATA COLLECTION AND ANALYSIS

We extracted data using a data extraction form designed for this review. We assessed methodological limitations using a list of predefined criteria. We extracted and assessed data regarding study authors' motivations for carrying out their study. We used a thematic synthesis approach to analyse and synthesise the evidence. We used the GRADE-CERQual (Confidence in the Evidence from Reviews of Qualitative research) approach to assess our confidence in each finding. We examined each review finding to identify factors that may influence intervention implementation and we developed implications for practice.

MAIN RESULTS

We included 11 studies in our review. Most studies explored healthcare workers' views and experiences about vaccination of older adults more broadly but also mentioned communication issues specifically. All studies were from high-income countries. The studies focused on doctors, nurses, pharmacists and others working in hospitals, clinics, pharmacies and nursing homes. These healthcare workers discussed different types of vaccines, including influenza, pneumococcal and herpes zoster vaccines. The review was carried out before COVID-19 vaccines were available. We downgraded our confidence in several of the findings from high confidence to moderate, low or very low confidence. One reason for this was that some findings were based on only small amounts of data. Another reason was that the findings were based on studies from only a few countries, making us unsure about the relevance of these findings to other settings. Healthcare workers reported that older adults asked about vaccination to different extents, ranging from not asking about vaccines at all, to great demand for information (high confidence finding). When the topic of vaccination was discussed, healthcare workers described a lack of information, and presence of misinformation, fears and concerns about vaccines among older adults (moderate confidence). The ways in which healthcare workers discussed vaccines with older adults appeared to be linked to what they saw as the aim of vaccination communication. Healthcare workers differed among themselves in their perceptions of this aim and about their own roles and the roles of older adults in vaccine decisions. Some healthcare workers thought it was important to provide information but emphasised the right and responsibility of older adults to decide for themselves. Others used information to persuade and convince older adults to vaccinate in order to increase 'compliance' and 'improve' vaccination rates, and in some cases to gain financial benefits. Other healthcare workers tailored their approach to what they believed the older adult needed or wanted (moderate confidence). Healthcare workers believed that older adults' decisions could be influenced by several factors, including the nature of the healthcare worker-patient relationship, the healthcare worker's status, and the extent to which healthcare workers led by example (low confidence). Our review also identified factors that are likely to influence how communication between healthcare workers and older adults take place. These included issues tied to healthcare workers' views and experiences regarding the diseases in question and the vaccines; as well as their views and experiences of the organisational and practical implementation of vaccine services.

AUTHORS' CONCLUSIONS

There is little research focusing specifically on healthcare workers' perceptions and experiences of communication with older adults about vaccination. The studies we identified suggest that healthcare workers differed among themselves in their perceptions about the aim of this communication and about the role of older adults in vaccine decisions. Based on these findings and the other findings in our review, we have developed a set of questions or prompts that may help health system planners or programme managers when planning or implementing strategies for vaccination communication between healthcare workers and older adults.

European data sources for computing burden of (potential) vaccine-preventable diseases in ageing adults

BACKGROUND

To guide decision-making on immunisation programmes for ageing adults in Europe, one of the aims of the Vaccines and InfecTious diseases in the Ageing popuLation (IMI2-VITAL) project is to assess the burden of disease (BoD) of (potentially) vaccine-preventable diseases ((P)VPD). We aimed to identify the available data sources to calculate the BoD of (P)VPD in participating VITAL countries and to pinpoint data gaps. Based on epidemiological criteria and vaccine availability, we prioritized (P) VPD caused by Extra-intestinal pathogenic Escherichia coli (ExPEC), norovirus, respiratory syncytial virus, Staphylococcus aureus, and pneumococcal pneumonia.

METHODS

We conducted a survey on available data (e.g. incidence, mortality, disability-adjusted life years (DALY), quality-adjusted life years (QALY), sequelae, antimicrobial resistance (AMR), etc.) among national experts from European countries, and carried out five pathogen-specific literature reviews by searching MEDLINE for peer-reviewed publications published between 2009 and 2019.

RESULTS

Morbidity and mortality data were generally available for all five diseases, while summary BoD estimates were mostly lacking. Available data were not always stratified by age and risk group, which is especially important when calculating BoD for ageing adults. AMR data were available in several countries for S. aureus and ExPEC.

CONCLUSION

This study provides an exhaustive overview of the available data sources and data gaps for the estimation of BoD of five (P) VPD in ageing adults in the EU/EAA, which is useful to guide pathogen-specific BoD studies and contribute to calculation of (P)VPDs BoD.

Measles vaccine coverage among children born to Somali immigrants in Norway

Background

Despite overall good vaccination coverage in many countries, vaccine hesitancy has hindered full coverage and exposed groups to the risk of outbreaks. Somali immigrant groups have been known to have low measles vaccination coverage, leading to outbreaks in their communities. Current research indicates a general lack of trust in the healthcare system, the use of alternative information sources and inadequate health literacy can be contributing factors. We explore measles vaccine coverage in children born to Somali parents in Norway, whether it has changed over time and factors that may influence coverage.

Methods

Data was extracted from the National Population Register on all children born in Norway from 2000 to 2016, where both parents originated from Somalia. Date of birth, gender, residential area at birth and date of immigration and emigration for both parents was linked to information on measles vaccination from the National Immunisation Register.

Results

We found that children born to Somali immigrants in Norway had suboptimal measles vaccine coverage at 2 years; for children born in 2016 the coverage was 85%. Coverage declined between 2000 and 2016, and at a greater rate for boys than girls. Children born to mothers residing in Norway for 6 years or more had lower coverage compared to those with mothers residing less than 2 years prior to their birth. Children born in the capital and surrounding county had significantly lower coverage than children born elsewhere in Norway.

Discussion

New targeted interventions are needed to improve measles vaccine coverage among Somali immigrants in Norway. Some possible strategies include using Somali social media platforms, improving communication with Somali parents and tighter cooperation between various countries’ vaccination programmes.

A Systematic Review of Studies Published between 2016 and 2019 on the Effectiveness and Efficacy of Pneumococcal Vaccination on Pneumonia and Invasive Pneumococcal Disease in an Elderly Population

Adult vaccination is high on the agenda in many countries. Two different vaccines are available for the prevention of pneumococcal disease in adults: a 23-valent polysaccharide vaccine (PPV23), and a 13-valent conjugated vaccine (PCV13). The objective of this review is to update the evidence base for vaccine efficacy and effectiveness of PPV23 and PCV13 against invasive pneumococcal disease and pneumonia among an unselected elderly population. We systematically searched for clinical trials and observational studies published between January 1 2016 and April 17 2019 in Pubmed, Embase, Cinahl, Web of Science, Epistemonikos and Cochrane databases. Risk of bias was assessed using Cochrane Risk of Bias tool for and the Newcastle–Ottawa Scale. Results were stratified by vaccine type and outcome. We identified nine studies on PCV13 and six on PPV23. No new randomized clinical trials were identified. Due to different outcomes, it was not possible to do a meta-analysis. New high-quality observational studies indicate protective vaccine effectiveness for both vaccines against vaccine type pneumonia. Our estimates for the protective vaccine efficacy and effectiveness (VE) of PPV23 on pneumonia and pneumococcal pneumonia overlap with results from previously published reviews. Some of the results indicate that the effectiveness of the PPV23 is best in younger age groups, and that it decreases over time.

A qualitative study of health experiences of Ethiopian asylum seekers in Norway

BACKGROUND

Norway, like other European countries, has a growing refugee population. Upon arrival to Norway, refugees and asylum seekers need to learn about Norwegian society and social services such as healthcare. Despite various programs and assistance, they face numerous challenges using the healthcare system. Understanding the healthcare experiences of Ethiopian refugees and asylum seekers may improve how services such as informational sessions and delivery of medical care are provided. This qualitative study seeks to describe the health-related experiences of Ethiopians who have sought asylum in Norway and shed light on potential barriers to care.

METHODS

Individual interviews were conducted with ten Ethiopian refugees and asylum seekers in Norway. Thematic analysis was used to understand the broader context of refugee resettlement and how this experience influences participants' health experiences and health seeking behaviors.

RESULTS

We identified three main themes that played a role in participants' health and healthcare experiences. Participants described how 'living in limbo' during their application for residency took a mental toll, the difficulties they had 'using the healthcare system', and the role 'interpersonal factors' had on their experiences. While applying for asylum, participants felt consumed by the process and were affected by the lack of structure in their lives, the conditions in the reception center, and perceived inadequate healthcare. Participants perceived a change in access to services before and after they had been granted residency. Participants learned about the healthcare system both through official information sessions and social networks. Doctor-patient communication and interpersonal factors such as a sense of feeling valued, language, and discrimination had a large impact on perceived quality of care.

CONCLUSIONS

Ethiopian refugees and asylum seekers face numerous challenges accessing, using, and interacting with Norway's healthcare system. Contextualizing these challenges within the asylum seeking process may help policy makers better understand, and therefore address, these challenges. Interventions offered at reception centers and in health worker trainings may improve healthcare experiences for this and similar populations.

Wanting to or having to - a qualitative study of experiences and attitudes towards migrant screening for tuberculosis in Norway

Background

This study assesses how tuberculosis (TB) screening is perceived by immigrants in Norway. Screening is mandatory for people arriving from high incidence countries. To attend screening, immigrants have to contact the health system after receiving an invitation by letter. The proportion of non-attenders is not known, and there are no sanctions for not attending. Generally, only persons who test positive receive test results. The study explores users’ experiences, attitudes and motivations for attending or not attending TB screening, and perceived barriers and enablers.

Methods

We conducted six focus group discussions and three individual interviews with 34 people from 16 countries in Africa, Asia and Europe. Interviews were recorded and transcribed, and data was coded following a general inductive approach: All transcribed text data was closely read through, salient themes were identified and categories were created and labelled. The data was read through several times and the category system was subsequently revised.

Results

Most appreciated the opportunity to be tested for a severe disease and were generally positive towards the healthcare system. At the same time, many were uncomfortable with screening, particularly due to the fear and stigma attached to TB. All experienced practical problems related to language, information, and accessing facilities. Having to ask others for help made them feel dependent and vulnerable. Positive and negative attitudes simultaneously created ambivalence. Many wanted “structuring measures” like sanctions to help attendance. Many said that not receiving results left them feeling anxious.

Conclusions

In order to adapt the system and improve trust and patient uptake, all aspects of the screening should be taken into account. Ambivalence towards screening probably has a negative impact on screening uptake and should be sought reduced. A combination of ambivalence and a wish for “structuring measures” leads the authors to conclude that mandatory screening is a reasonable measure. However, since mandatory screening negatively impacts patient autonomy, and because of fear, stigma and practical problems, the health system should empower users by improving communication and access to services. In addition, it is recommended that negative test results are also communicated to the users.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-7128-z) contains supplementary material, which is available to authorized users.

Immigrant screening for latent tuberculosis infection: numbers needed to test and treat, a Norwegian population-based cohort study

OBJECTIVES

To estimate the number needed to screen (NNS) and the number needed to treat (NNT) to prevent one tuberculosis (TB) case in the Norwegian immigrant latent tuberculosis infection (LTBI) screening programme and to explore the effect of delay of LTBI treatment initiation.

DESIGN

Population-based, prospective cohort study.

PARTICIPANTS

Immigrants to Norway.

OUTCOME

Incident TB.

METHODS

We obtained aggregated data on immigration to Norway in 2008-2011 and used data from the Norwegian Surveillance System for Infectious Diseases to assess the number of TB cases arising in this cohort within 5 years after arrival. We calculated the average NNS and NNT for immigrants from the top 10 source countries for TB in Norway and by estimated TB incidence rates in source countries. We explored the sensitivity of these estimates with regard to test performance, treatment efficacy and treatment adherence using an extreme value approach, and assessed the effects of emigration, time to TB diagnosis (to define incident TB) and intervention timing.

RESULTS

NNS and NNT were overall high, with substantial variation. NNT showed numerically stronger negative correlation with TB notification rate in Norway (-0.75 [95% CI -1.00 to -0.44]) than with the WHO incidence rate (IR) (-0.32 [95% CI -0.93 to 0.29]). NNT was affected substantially by emigration and the definition of incident TB. Estimates were lowest for Somali (NNS 99 [70-150], NNT 27 [19-41]) and highest for Thai immigrants (NNS 585 [413-887], NNT 111 [79-116]). Implementing LTBI treatment in immigrants sooner after arrival may improve the effectiveness of the programme.

CONCLUSION

Using TB notifications in Norway, rather than IR in source countries, would improve targeting of immigrants for LTBI management. However, the overall high NNT is a concern and challenges the scale-up of preventive LTBI treatment for significant public health impact. Better data are urgently needed to monitor and evaluate NNS and NNT in countries implementing LTBI screening.

Treatment completion for latent tuberculosis infection in Norway: a prospective cohort study

Background

Successful treatment of latent tuberculosis infection (LTBI) is essential to reduce tuberculosis (TB) incidence rates in low-burden countries. This study measures treatment completion and determinants of non-completion of LTBI treatment in Norway in 2016.

Methods

This prospective cohort study included all individuals notified with LTBI treatment to the Norwegian Surveillance System for Infectious Diseases (MSIS) in 2016. We obtained data from MSIS and from a standardized form that was sent to health care providers at the time of patient notification to MSIS. We determined completion rates. Pearson’s chi squared test was used to study associations between pairs of categorical variables and separate crude and multivariable logistic regression models were used to identify factors associated with treatment completion and adverse drug effects.

Results

We obtained information on treatment completion from 719 of the 726 individuals notified for LTBI treatment in 2016. Overall, 91% completed treatment. Treatment completion was highest in the foreign-born group [foreign-born, n = 562 (92%) vs Norwegian-born, n = 115 (85%), p = 0.007]. Treatment completion did not differ significantly between prescribed regimens (p = 0.124). Adverse events were the most common reason for incomplete treatment. We found no significant differences in adverse events when comparing weekly rifapentine (3RPH) with three months daily isoniazid and rifampicin (3RH). However, there were significantly fewer adverse events with 3RPH compared to other regimens (p = 0.037). Age over 35 years was significantly associated with adverse events irrespective of regimen (p = 0.024), whereas immunosuppression was not significantly associated with adverse events after adjusting for other variables (p = 0.306). Treatment under direct observation had a significant effect on treatment completion for foreign-born (multivariate Wald p-value = 0.017), but not for Norwegian-born (multivariate Wald p-value = 0.408) individuals.

Conclusions

We report a very high treatment completion rate, especially among individuals from countries with high TB incidence. The follow-up from tuberculosis-coordinators and the frequent use of directly observed treatment probably contributes to this. Few severe adverse events were reported, even with increased age and in individuals that are more susceptible. While these results are promising, issues of cost-effectiveness and targeting treatment to individuals at highest risk of TB are important components of public health impact.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3468-z) contains supplementary material, which is available to authorized users.

Stratification by interferon-γ release assay level predicts risk of incident TB

INTRODUCTION

Targeted testing and treatment of latent TB infection (LTBI) are priorities on the global health agenda, but LTBI management remains challenging. We aimed to evaluate the prognostic value of the QuantiFERON TB-Gold (QFT) test for incident TB, focusing on the interferon (IFN)-γ level, when applied in routine practice in a low TB incidence setting.

METHODS

In this large population-based prospective cohort, we linked QFT results in Norway (1 January 2009-30 June 2014) with national registry data (Norwegian Surveillance System for Infectious Diseases, Norwegian Prescription Database, Norwegian Patient Registry and Statistics Norway) to assess the prognostic value of QFT for incident TB. Participants were followed until 30 June 2016. We used restricted cubic splines to model non-linear relationships between IFN-γ levels and TB, and applied these findings to a competing risk model.

RESULTS

The prospective analyses included 50 389 QFT results from 44 875 individuals, of whom 257 developed TB. Overall, 22% (n=9878) of QFT results were positive. TB risk increased with the IFN-γ level until a plateau level, above which further increase was not associated with additional prognostic information. The HRs for TB were 8.8 (95% CI 4.7 to 16.5), 19.2 (95% CI 11.6 to 31.6) and 31.3 (95% CI 19.8 to 49.5) times higher with IFN-γ levels of 0.35 to <1.00, 1.00 to <4.00 and >4.00 IU/mL, respectively, compared with negative tests (<0.35 IU/mL).

CONCLUSIONS

Consistently, QFT demonstrates increased risk of incident TB with rising IFN-γ concentrations, indicating that IFN-γ levels may be used to guide targeted treatment of LTBI.

Does early vitamin B12 supplementation improve neurodevelopment and cognitive function in childhood and into school age: a study protocol for extended follow-ups from randomised controlled trials in India and Tanzania

INTRODUCTION

As many as 250 million children under the age of 5 may not be reaching their full developmental potential partly due to poor nutrition during pregnancy and the first 2 years of life. Micronutrients, including vitamin B₁₂, are important for the development of brain structure and function; however, the timing, duration and severity of deficiencies may alter the impact on functional development outcomes. Consequently, to fully explore the effect of vitamin B₁₂ on cognitive function, it is crucial to measure neurodevelopment at different ages, in different populations and with vitamin B₁₂ supplementation at different times during the critical periods of neurodevelopment.

METHODS AND ANALYSIS

In this project, we follow up children from four recently completed randomised placebo-controlled trials of oral vitamin B₁₂ supplementation, two in India and two in Tanzania, to explore the long-term effects on neurodevelopmental outcomes and growth. All the included trials provided at least two recommended dietary allowances of oral vitamin B₁₂ daily for at least 6 months. Vitamin B₁₂ was supplemented either during pregnancy, early infancy or early childhood. Primary outcomes are neurodevelopmental status, cognitive function and growth later in childhood. We apply validated and culturally appropriate instruments to identify relevant developmental outcomes. All statistical analyses will be done according to intention-to-treat principles. The project provides an excellent opportunity to examine the effect of vitamin B₁₂ supplementation in different periods during early life and measure the outcomes later in childhood.

ETHICS AND DISSEMINATION

The study has received ethical approvals from all relevant authorities in Norway, USA, Tanzania and India and complies fully with ethical principles for medical research. Results will be presented at national and international research and policy meetings and published in peer-reviewed scientific journals, preferably open access.

TRIAL REGISTRATION NUMBER

NCT00641862 (Bangalore); NCT00717730, updated CTRI/2016/11/007494 (Delhi); NCT00197548 and NCT00421668 (Dar es Salaam).

Multidrug-resistant tuberculosis in Norway: a nationwide study, 1995-2014

SETTING

The management of multidrug-resistant tuberculosis (MDR-TB) is strictly regulated in Norway. However, nationwide studies of the epidemic are lacking.

OBJECTIVE

To describe the MDR-TB epidemic in Norway over two decades.

DESIGN

Retrospective analysis of data on MDR-TB cases in Norway, 1995-2014, obtained from the national registry, patient records and the reference laboratory, with genotyping and cluster analysis data. Data for non-MDR-TB cases were collected from the national registry.

RESULTS

Of 4427 TB cases, 89 (2.0%) had MDR-TB, 7% of whom had extensively drug-resistant TB (XDR-TB) and 24% pre-XDR-TB. Of the 89 MDR-TB cases, 96% were immigrants, mainly from the Horn of Africa or the former Soviet Union (FSU); 37% had smear-positive TB; and 4% were human immunodeficiency virus co-infected. Of the 19% infected in Norway, the majority belonged to a Delhi/Central Asian lineage cluster in a local Somali community. Among the MDR-TB cases, smear-positive TB and FSU origin were independent risk factors for XDR/pre-XDR-TB. Treatment was successful in 66%; 17% were lost to follow-up, with illicit drug use and adolescence being independent risk factors. Forty-four per cent of patients treated with linezolid discontinued treatment due to adverse effects.

CONCLUSION

MDR-TB is rare in Norway and is predominantly seen in immigrants from the Horn of Africa and FSU. Domestic transmission outside immigrant populations is minimal.

Immigrant screening for latent tuberculosis in Norway: a cost-effectiveness analysis

The incidence of tuberculosis (TB) disease has increased in Norway since the mid-1990s. Immigrants are screened, and some are treated, for latent TB infection (LTBI) to prevent TB disease (reactivation). In this study, we estimated the costs of both treating and screening for LTBI and TB disease, which has not been done previously in Norway. We developed a model to indicate the cost-effectiveness of four different screening algorithms for LTBI using avoided TB disease cases as the health outcome. Further, we calculated the expected value of perfect information (EVPI), and indicated areas of LTBI screening that could be changed to improve cost-effectiveness. The costs of treating LTBI and TB disease were estimated to be €1938 and €15,489 per case, respectively. The model evaluates four algorithms, and suggests three cost-effective algorithms depending on the cost-effectiveness threshold. Screening all immigrants with interferon-gamma release assays (IGRA) requires the highest threshold (€28,400), followed by the algorithms "IGRA on immigrants with risk factors" and "no LTBI screening." EVPI is approximately €5 per screened immigrant. The costs for a cohort of 20,000 immigrants followed through 10 years range from €12.2 million for the algorithm "screening and treatment for TB disease but no LTBI screening," to €14 million for "screening all immigrants for both TB disease and LTBI with IGRA." The results suggest that the cost of TB disease screening and treatment is the largest contributor to total costs, while LTBI screening and treatment costs are relatively small. Increasing the proportion of IGRA-positive immigrants who are treated decreases the costs per avoided case substantially.

Compliance of mothers following recommendations to breastfeed or withhold breast milk during rotavirus vaccination in North India: a randomized clinical trial

BACKGROUND

Neutralizing antibodies in breast milk may adversely influence the immune response to live oral vaccines. Withholding breastfeeding around the time of vaccine administration has been suggested for improving vaccine performance. However, we do not know whether mothers find withholding breastfeeding around the time of vaccination acceptable and how they perceive this recommendation.

METHODS

In a clinical study designed to examine predictors of poor immune response to rotavirus vaccine in infants in India, Rotarix® was administered to infants at 6 and 10 weeks with other childhood vaccines. For the study, 400 mother-infant pairs were randomized into two groups in a 1:1 ratio. Mothers were either recommended to withhold breastfeeding or were encouraged to breastfeed half an hour before and after administration of Rotarix®. The mother-infant pairs were observed and the breastfeeding intervals were recorded during this period. Mothers were administered a questionnaire about their perception of the intervention after the infants received the second dose of Rotarix®.

RESULTS

Almost 98% (391/400) of the infants received both doses of Rotarix®. Adherence to the recommendations was high in both groups. All mothers in the group who were asked to withhold breastfeeding did so, except one who breastfed her infant before the recommended time after the first dose of Rotarix®. Of the mothers, 4% (7/195) reported that the recommendation to withhold breastfeeding was difficult to follow. All mothers in this group reported that they would withhold breastfeeding at the time of vaccination if they were asked to by a health-care provider. Only one mother responded that withholding breastfeeding would be a reason for not giving rotavirus vaccine to her infant.

CONCLUSIONS

Withholding breastfeeding half an hour before and after vaccination appears to be acceptable to mothers in this setting. If withholding breastfeeding produces an improvement in the performance of the vaccine, it could be used to increase the public health impact of rotavirus immunization.

TRIAL REGISTRATION

Clinical Trial Registry, India (CTRI/2012/10/003057), Clinicaltrials.gov (NCT01700127).Date of Registration: Clinical Trial Registry, India: 28 September 2012, Clinicaltrials.gov: 3 October 2012.

Wavelet principal component analysis of fetal movement counting data preceding hospital examinations due to decreased fetal movement: a prospective cohort study

Background

Fetal movement (FM) counting is a simple and widely used method of assessing fetal well-being. However, little is known about what women perceive as decreased fetal movement (DFM) and how maternally perceived DFM is reflected in FM charts.

Methods

We analyzed FM counting data from 148 DFM events occurring in 137 pregnancies. The women counted FM daily from pregnancy week 24 until birth using a modified count-to-ten procedure. Common temporal patterns for the two weeks preceding hospital examination due to DFM were extracted from the FM charts using wavelet principal component analysis; a statistical methodology particularly developed for modeling temporal data with sudden changes, i.e. spikes that are frequently found in FM data. The association of the extracted temporal patterns with fetal complications was assessed by including the individuals’ scores on the wavelet principal components as explanatory variables in multivariable logistic regression analyses for two outcome measures: (i) complications identified during DFM-related consultations (n = 148) and (ii) fetal compromise at the time of consultation (including relevant information about birth outcome and placental pathology). The latter outcome variable was restricted to the DFM events occurring within 21 days before birth (n = 76).

Results

Analyzing the 148 and 76 DFM events, the first three main temporal FM counting patterns explained 87.2% and 87.4%, respectively, of all temporal variation in the FM charts. These three temporal patterns represented overall counting times, sudden spikes around the time of DFM events, and an inverted U-shaped pattern, explaining 75.3%, 8.6%, and 3.3% and 72.5%, 9.6%, and 5.3% of variation in the total cohort and subsample, respectively. Neither of the temporal patterns was significantly associated with the two outcome measures.

Conclusions

Acknowledging that sudden, large changes in fetal activity may be underreported in FM charts, our study showed that the temporal FM counting patterns in the two weeks preceding DFM-related consultation contributed little to identify clinically important changes in perceived FM. It thus provides insufficient information for giving detailed advice to women on when to contact health care providers. The importance of qualitative features of maternally perceived DFM should be further explored.

Temporal patterns in count-to-ten fetal movement charts and their associations with pregnancy characteristics: a prospective cohort study

BACKGROUND

Fetal movement counting has long been suggested as a screening tool to identify impaired placental function. However, quantitative limits for decreased fetal movement perform poorly for screening purposes, indicating the need for methodological refinement. We aimed to identify the main individual temporal patterns in fetal movement counting charts, and explore their associations with pregnancy characteristics.

METHODS

In a population-based prospective cohort in Norway, 2009-2011, women with singleton pregnancies counted fetal movements daily from pregnancy week 24 until delivery using a modified "count-to-ten" procedure. To account for intra-woman correlation of observations, we used functional data analysis and corresponding functional principal component analysis to identify the main individual temporal patterns in fetal movement count data. The temporal patterns are described by continuous functional principal component (FPC) curves, with an individual score on each FPC for each woman. These scores were later used as outcome variables in multivariable linear regression analyses, with pregnancy characteristics as explanatory variables.

RESULTS

Fetal movement charts from 1086 pregnancies were included. Three FPC curves explained almost 99% of the variation in the temporal data, with the first FPC, representing the individual overall counting time, accounting for 91% alone. There were several statistically significant associations between the FPCs and various pregnancy characteristics. However, the effects were small and of limited clinical value.

CONCLUSIONS

This statistical approach for analyzing fetal movement counting data successfully captured clinically meaningful individual temporal patterns and how these patterns vary between women. Maternal body mass index, gestational age and placental site explained little of the variation in the temporal fetal movement counting patterns. Thus, a perceived decrease in fetal movement should not be attributed to a woman's basic pregnancy characteristics, but assessed as a potential marker of risk.

A comparative examination of tuberculosis immigration medical screening programs from selected countries with high immigration and low tuberculosis incidence rates

BACKGROUND

Tuberculosis (TB) in migrants is an ongoing challenge in several low TB incidence countries since a large proportion of TB in these countries occurs in migrants from high incidence countries. To meet these challenges, several countries utilize TB screening programs. The programs attempt to identify and treat those with active and/or infectious stages of the disease. In addition, screening is used to identify and manage those with latent or inactive disease after arrival. Between nations, considerable variation exists in the methods used in migration-associated TB screening. The present study aimed to compare the TB immigration medical examination requirements in selected countries of high immigration and low TB incidence rates.

METHODS

Descriptive study of immigration TB screening programs.

RESULTS

16 out of 18 eligible countries responded to the written standardized survey and phone interview. Comparisons in specific areas of TB immigration screening programs included authorities responsible for TB screening, the primary objectives of the TB screening program, the yield of detection of active TB disease, screening details and aspects of follow up for inactive pulmonary TB. No two countries had the same approach to TB screening among migrants. Important differences, common practices, common problems, evidence or lack of evidence for program specifics were noted.

CONCLUSIONS

In spite of common goals, there is great diversity in the processes and practices designed to mitigate the impact of migration-associated TB among nations that screen migrants for the disease. The long-term goal in decreasing migration-related introduction of TB from high to low incidence countries remains diminishing the prevalence of the disease in those high incidence locations. In the meantime, existing or planned migration screening programs for TB can be made more efficient and evidenced based. Cooperation among countries doing research in the areas outlined in this study should facilitate the development of improved screening programs.

Predictive values of QuantiFERON-TB Gold testing in screening for tuberculosis disease in asylum seekers

Screening with chest X-ray and the Mantoux test (the tuberculin skin test [TST]) is compulsory for adult asylum seekers who arrive in Norway. In 2005-2006, we included 823 asylum seekers in a study of the QuantiFERON-TB Gold test (QFT-G), and followed them for 23-32 months. Eight subjects with a positive and one with a negative QFT-G test were diagnosed with tuberculosis (TB). The positive (PPV) and negative predictive values (NPV) for TB were respectively 3.3% and 99.8%. The PPV was 2.3% and the NPV 99.1% for TST >or= 15 mm, and the NPV was 99.5% for TST >or= 6 mm in combination with a negative QFT-G.

[Drug resistance in tuberculosis]

BACKGROUND

The emergence of drug-resistant tuberculosis is one of the main challenges in the global combat against tuberculosis. The objective of the article is to discuss the main causes for emergence of drug resistance, describe the epidemiology of drug-resistant tuberculosis with focus on the situation in Norway and advise on how this should be managed.

MATERIAL AND METHOD

This review is based on relevant published literature, data from surveillance of the disease in Norway and current national and international recommendations for prevention and control of tuberculosis.

RESULTS

Tuberculosis can normally be treated effectively with a standardized combination of drugs for six months. The long duration of treatment is a challenge and incorrect treatment causes development of resistant tuberculosis. The objectives of tuberculosis treatment are to cure the patient, to stop transmission of the bacteria and prevent emergence of drug resistance. The total number of patients diagnosed with multidrug resistant tuberculosis (MDR)-TB in Norway is low, although a threefold increase has occurred in the last decade compared to in previous decades. Most patients were born abroad. Treatment of MDR-TB takes up to two years, is costly and has more side effects. Treatment of MDR-TB is associated with lower cure rate and higher fatality; although in Norway most cases are cured.

DISCUSSION

The global situation also affects Norway. Early diagnosis of infectious cases and close monitoring of patients under treatment, by direct observation of medication, can prevent new cases of MDR-TB.

School based screening for tuberculosis infection in Norway: comparison of positive tuberculin skin test with interferon-gamma release assay

Background

In Norway, screening for tuberculosis infection by tuberculin skin test (TST) has been offered for several decades to all children in 9th grade of school, prior to BCG-vaccination. The incidence of tuberculosis in Norway is low and infection with M. tuberculosis is considered rare. QuantiFERON^®TB Gold (QFT) is a new and specific blood test for tuberculosis infection. So far, there have been few reports of QFT used in screening of predominantly unexposed, healthy, TST-positive children, including first and second generation immigrants. In order to evaluate the current TST screening and BCG-vaccination programme we aimed to (1) measure the prevalence of QFT positivity among TST positive children identified in the school based screening, and (2) measure the association between demographic and clinical risk factors for tuberculosis infection and QFT positivity.

Methods

This cross-sectional multi-centre study was conducted during the school year 2005–6 and the TST positive children were recruited from seven public hospitals covering rural and urban areas in Norway. Participation included a QFT test and a questionnaire regarding demographic and clinical risk factors for latent infection. All positive QFT results were confirmed by re-analysis of the same plasma sample. If the confirmatory test was negative the result was reported as non-conclusive and the participant was offered a new test.

Results

Among 511 TST positive children only 9% (44) had a confirmed positive QFT result. QFT positivity was associated with larger TST induration, origin outside Western countries and known exposure to tuberculosis. Most children (79%) had TST reactions in the range of 6–14 mm; 5% of these were QFT positive. Discrepant results between the tests were common even for TST reactions above 15 mm, as only 22 % had a positive QFT.

Conclusion

The results support the assumption that factors other than tuberculosis infection are widely contributing to positive TST results in this group and indicate the improved specificity of QFT for latent tuberculosis. Our study suggests a very low prevalence of latent tuberculosis infection among 9th grade school children in Norway. The result will inform the discussion in Norway of the usefulness of the current TST screening and BCG-policy.

Screening for tuberculosis infection among newly arrived asylum seekers: comparison of QuantiFERONTB Gold with tuberculin skin test

Background

QuantiFERON^®TB Gold (QFT) is a promising blood test for tuberculosis infection but with few data so far from immigrant screening. The aim of this study was to compare results of QFT and tuberculin skin test (TST) among newly arrived asylum seekers in Norway and to assess the role of QFT in routine diagnostic screening for latent tuberculosis infection.

Methods

The 1000 asylum seekers (age ≥ 18 years) enrolled in the study were voluntarily recruited from 2813 consecutive asylum seekers arriving at the national reception centre from September 2005 to June 2006. Participation included a QFT test and a questionnaire in addition to the mandatory TST and chest X-ray.

Results

Among 912 asylum seekers with valid test results, 29% (264) had a positive QFT test whereas 50% (460) tested positive with TST (indurations ≥ 6 mm), indicating a high proportion of latent infection within this group. Among the TST positive participants 50% were QFT negative, whereas 7% of the TST negative participants were QFT positive. There was a significant association between increase in size of TST result and the likelihood of being QFT positive. Agreement between the tests was 71–79% depending on the chosen TST cut-off and it was higher for non-vaccinated individuals.

Conclusion

By using QFT in routine screening, further follow-up could be avoided in 43% of the asylum seekers who would have been referred if based only on a positive TST (≥ 6 mm). The proportion of individuals referred will be the same whether QFT replaces TST or is used as a supplement to confirm a positive TST, but the number tested will vary greatly. All three screening approaches would identify the same proportion (88–89%) of asylum seekers with a positive QFT and/or a TST ≥ 15 mm, but different groups will be missed.

Tuberculosis in contacts need not indicate disease transmission

BACKGROUND

Traditional contact investigation is an important tool for controlling tuberculosis. It may also help to indicate drug susceptibility patterns when Mycobacterium tuberculosis cultures are not available. Such investigations often underestimate the degree of transmission found by genotyping, but overestimation may also occur. This report is the result of a routine successive DNA restriction fragment length polymorphism (RFLP) analysis of M tuberculosis isolated in Norway.

METHOD

Fifteen immigrants belonging to the same community were notified with tuberculosis during February to September 2003. The mycobacterial isolates were analysed by RFLP.

RESULTS

All 15 patients had social contact with each other and 13 belonged to the same church community. A total of 14 cultures were positive for M tuberculosis. Among these isolates, six different genotypes were found. Five patients had not acquired the infection from the putative source.

CONCLUSIONS

Reactivation of tuberculosis may occur in contacts during the development of an outbreak. In such situations, traditional contact investigations may overestimate the rate of transmission found by genotyping of M tuberculosis. When cultures are unavailable and presumed drug susceptibility patterns are based on that of contacts, such overestimation may lead to incorrect treatment of a patient. Contact investigations must be combined with genotyping of M tuberculosis to conclude how tuberculosis is transmitted. This is especially important in persons with several risk factors for infection.