Hilde Kløvstad

A Large Outbreak of Hepatitis E among a Displaced Population in Darfur, Sudan, 2004: The Role of Water Treatment Methods

BACKGROUND The conflict in Darfur, Sudan, was responsible for the displacement of 1.8 million civilians. We investigated a large outbreak of hepatitis E virus (HEV) infection in Mornay camp (78,800 inhabitants) in western Darfur. METHODS To describe the outbreak, we used clinical and demographic information from cases recorded at the camp between 26 July and 31 December 2004. We conducted a case-cohort study and a retrospective cohort study to identify risk factors for clinical and asymptomatic hepatitis E, respectively. We collected stool and serum samples from animals and performed a bacteriological analysis of water samples. Human samples were tested for immunoglobulin G and immunoglobulin M antibody to HEV (for serum samples) and for amplification of the HEV genome (for serum and stool samples). RESULTS In 6 months, 2621 hepatitis E cases were recorded (attack rate, 3.3%), with a case-fatality rate of 1.7% (45 deaths, 19 of which involved were pregnant women). Risk factors for clinical HEV infection included age of 15-45 years (odds ratio, 2.13; 95% confidence interval, 1.02-4.46) and drinking chlorinated surface water (odds ratio, 2.49; 95% confidence interval, 1.22-5.08). Both factors were also suggestive of increased risk for asymptomatic HEV infection, although this was not found to be statistically significant. HEV RNA was positively identified in serum samples obtained from 2 donkeys. No bacteria were identified from any sample of chlorinated water tested. CONCLUSIONS Current recommendations to ensure a safe water supply may have been insufficient to inactivate HEV and control this epidemic. This research highlights the need to evaluate current water treatment methods and to identify alternative solutions adapted to complex emergencies.

High Mortality Associated with an Outbreak of Hepatitis E among Displaced Persons in Darfur, Sudan

BACKGROUND Hepatitis E virus (HEV) causes acute onset of jaundice and a high case-fatality ratio in pregnant women. We provide a clinical description of hospitalized case patients and assess the specific impact on pregnant women during a large epidemic of HEV infection in a displaced population in Mornay camp (78,800 inhabitants), western Darfur, Sudan. METHODS We reviewed hospital records. A sample of 20 clinical cases underwent laboratory confirmation. These patients were tested for immunoglobulin G (IgG) and immunoglobulin M (IgM) antibody to HEV (serum) and for amplification of the HEV genome (serum and stool). We performed a cross-sectional survey in the community to determine the attack rate and case-fatality ratio in pregnant women. RESULTS Over 6 months, 253 HEV cases were recorded at the hospital, of which 61 (24.1%) were in pregnant women. A total of 72 cases (39.1% of those for whom clinical records were available) had a diagnosis of hepatic encephalopathy. Of the 45 who died (case-fatality ratio, 17.8%), 19 were pregnant women (specific case-fatality ratio, 31.1%). Acute hepatitis E was confirmed in 95% (19/20) of cases sampled; 18 case-patients were positive for IgG (optical density ratio > or =3), for IgM (optical density ratio >2 ), or for both, whereas 1 was negative for IgG and IgM but positive for HEV RNA in serum. The survey identified 220 jaundiced women among the 1133 pregnant women recorded over 3 months (attack rate, 19.4%). A total of 18 deaths were recorded among these jaundiced pregnant women (specific case-fatality ratio, 8.2%). CONCLUSIONS This large epidemic of HEV infection illustrates the dramatic impact of this disease on pregnant women. Timely interventions and a vaccine are urgently needed to prevent mortality in this special group.

Chlamydia trachomatis infections in Norway, 1986 to 2006, surveillance data.

Introduction: The number of Chlamydia trachomatis infections in Norway has been increasing for the last years. A new and enhanced surveillance system was implemented in 2005 to meet the challenges faced by the increasing number of cases. Methods: The new surveillance system is laboratory based. Data are collected once a year from all laboratories on the total number of test performed, and all diagnosed cases from the preceding year. For each case the following variables are reported: date of diagnosis, birth year, sex, and municipality of residence. Results: By 2006 all laboratories reported data as required. We have observed an increase in yearly diagnosed C. trachomatis cases in Norway during the last years. In 2006, the incidence was 4.6 per 1000 population. The proportion positive tests have increased from 6.0% in 2000 to 7.7% in 2006. In the same period the annual number of tests increased by 13.5%. Surveillance data from 2006 showed that the highest incidence rates were found in women between the ages of 15 to 24 in men aged 20 to 24 and in 2 northernmost regions of the country. Conclusion: The year 2006 had the highest level of diagnosed cases ever in Norway. To better interpret the observed trend, a voluntary system will be introduced in 2007 to collect test rates by age, gender and geography. There is a need to evaluate current and new strategies to target the group of asymptomatic and untreated young people.

Population based study of genital Chlamydia trachomatis prevalence and associated factors in Norway: A cross sectional study

BackgroundThe number of diagnosed cases of Chlamydia trachomatis infection has been increasing in the past years in Norway although the testing rate has been relatively stable. The aim of this study was to measure the prevalence of genital Chlamydia trachomatis in young men and women in one county in Norway and determine associated factors in order to better target preventive measures.MethodsWe mailed to a random sample of 10 000 persons aged 18–25 in Rogaland county a mail-back urine sample kit and a self-administered questionnaire with questions on socio-demographic details, health seeking behaviour and symptoms of and history of sexually transmitted diseases. Associations between current Clamydia trachomatis infection and the above mentioned factors were studied by multiple logistic regression.ResultsThe response rate among women was 18.9% (930/4923) and 11.9% (605/5077) among men. The prevalence of Chlamydia trachomatis infection was 5.8% (95% CI 4.5-6.8) among women and 5.1% (95% CI 3.8-6.8) among men. For men a greater number of partners during the last year (p for trend < 0.001), and living in a municipality without a local youth clinic increased the odds of infection (OR 8.6, 95% CI 2.2-33.9). For women a greater number of partners during the last year (p < 0.001) and not having consulted a family doctor for STIs (OR 2.1 95% CI 1.1-4.2) were positively associated with infection while not having a previous Chlamydia trachomatis diagnosis decreased the odds of having this infection (OR 0.3, 95% CI 0.2-0.7).ConclusionOur results indicate the importance of having a visible youth clinic in each municipality. It also suggests targeting women who have had a previous Chlamydia trachomatis infection diagnosed before.

Epidemiology of acute and chronic hepatitis B virus infection in Norway, 1992-2009

BackgroundNorway is classified as a low prevalence country for hepatitis B virus infection. Vaccination is only recommended for risk groups (intravenous drug users (IDUs), Men who have Sex with Men (MSM), immigrants and contacts of known carriers). We describe the epidemiology of reported cases of hepatitis B in Norway, during the years 1992-2009 in order to assess the validity of current risk groups and recommend preventive measures.MethodsWe used case based data from the national surveillance system on acute and chronic hepatitis B. The Norwegian Statistics Bureau provided population and migration data and the Norwegian Institute for Alcohol and Drug Research the estimated number of active IDUs between 2002-2007. Incidence rates (IR) and incidence rate ratios (IRR) for acute hepatitis B and notification rates (NR) and notification rate ratios (NRR) for chronic hepatitis B with 95% confidence intervals were calculated.ResultsThe annual IR of acute hepatitis B ranged from 0.7/100,000 (1992) to 10.6/100,000 (1999). Transmission occurred mainly among IDUs (64%) or through sexual contact (24%). The risk of acquiring acute hepatitis B was highest in people aged 20-29 (IRR = 6.6 [3.3-13.3]), and in males (IRR = 2.4 [1.7-3.3]). We observed two peaks of newly reported chronic hepatitis B cases in 2003 and 2009 (NR = 17.6/100,000 and 17.4/100,000, respectively). Chronic hepatitis B was more likely to be diagnosed among immigrants than among Norwegians (NRR = 93 [71.9-120.6]), and among those 20-29 compared to those 50-59 (NRR = 5.2 [3.5-7.9]).ConclusionsIDUs remain the largest risk group for acute hepatitis B. The observed peaks of chronic hepatitis B are related to increased immigration from high endemic countries and screening and vaccination of these groups is important to prevent further spread of infection. Universal screening of pregnant women should be introduced. A universal vaccination strategy should be considered, given the high cost of reaching the target populations. We recommend evaluating the surveillance system for hepatitis B as well as the effectiveness of screening and vaccinating immigrant populations.

Systematic screening with information and home sampling for genital Chlamydia trachomatis infections in young men and women in Norway: a randomized controlled trial

BackgroundAs most genital Chlamydia trachomatis infections are asymptomatic, many patients do not seek health care for testing. Infections remain undiagnosed and untreated. We studied whether screening with information and home sampling resulted in more young people getting tested, diagnosed and treated for chlamydia in the three months following the intervention compared to the current strategy of testing in the health care system.MethodWe conducted a population based randomized controlled trial among all persons aged 18–25 years in one Norwegian county (41 519 persons). 10 000 persons (intervention) received an invitation by mail with chlamydia information and a mail-back urine sampling kit. 31 519 persons received no intervention and continued with usual care (control). All samples from both groups were analysed in the same laboratory. Information on treatment was obtained from the Norwegian Prescription Database (NorPD). We estimated risk ratios and risk differences of being tested, diagnosed and treated in the intervention group compared to the control group.ResultsIn the intervention group 16.5% got tested and in the control group 3.4%, risk ratio 4.9 (95% CI 4.5-5.2). The intervention led to 2.6 (95% CI 2.0-3.4) times as many individuals being diagnosed and 2.5 (95% CI 1.9-3.4) times as many individuals receiving treatment for chlamydia compared to no intervention in the three months following the intervention.ConclusionIn Norway, systematic screening with information and home sampling results in more young people being tested, diagnosed and treated for chlamydia in the three months following the intervention than the current strategy of testing in the health care system. However, the study has not established that the intervention will reduce the chlamydia prevalence or the risk of complications from chlamydia.Trial registrationClinicalTrials.gov IDNCT00283127

Denominators count: supplementing surveillance data for genital Chlamydia trachomatis infection with testing data, Norway, 2007 to 2013

As genital Chlamydia trachomatis (chlamydia) infection is often asymptomatic, surveillance of diagnosed cases is heavily influenced by the rate and distribution of testing. In 2007, we started supplementing case-based surveillance data from the Norwegian Surveillance System for Communicable Diseases (MSIS) with aggregated data on age group and sex of individuals tested. In this report, annual testing rates, diagnosis rates and proportion positive for chlamydia in Norway between 1990 and 2013 are presented. From 2007, rates are also stratified by age group and sex. The annual testing rate for chlamydia culminated in the early 1990s, with 8,035 tested per 100,000 population in 1991. It then declined to 5,312 per 100,000 in 2000 after which it remained relatively stable. Between 1990 and 2013 the annual rate of diagnosed cases increased 1.5 times from ca 300 to ca 450 per 100,000 population. The proportion of positive among the tested rose twofold from ca 4% in the 1990s to 8% in 2013. Data from 2007 to 2013 indicate that more women than men were tested (ratio: 2.56; 95% confidence interval (CI): 2.56-2.58) and diagnosed (1.54; 95% CI: 1.52-1.56). Among tested individuals above 14 years-old, the proportion positive was higher in men than women for all age groups. Too many tests are performed in women aged 30 years and older, where 49 of 50 tests are negative. Testing coverage is low (15%) among 15 to 24 year-old males. Information on sex and age-distribution among the tested helps to interpret surveillance data and provides indications on how to improve targeting of testing for chlamydia. Regular prevalence surveys may address remaining limitations of surveillance.

Economic Evaluation of Direct-Acting Antivirals for Hepatitis C in Norway

PurposeNew direct-acting antiviral (DAA) drugs have revolutionized the treatment of hepatitis C in recent years.ObjectiveOur objective was to analyse the cost effectiveness of combinations of different DAAs compared with ribavirin and peginterferon-α-2a, taking into account rebates from tender negotiations.MethodsWe used a compartmental model specifically developed for Norway to simulate hepatitis C and complications with and without different DAAs. All costs were based on Norwegian fees and estimates, estimating healthcare sector costs for the year 2016. We performed Monte Carlo simulations on uncertain input parameters to facilitate probabilistic sensitivity analyses.ResultsFor patients diagnosed with genotype 1, the combination of paritaprevir, ritonavir, ombitasvir and dasabuvir was cost effective compared with eight other available alternatives, given a cost-effectiveness threshold of €70,000 per quality-adjusted life-year. For genotype 2, the combination of sofosbuvir and ribavirin was the most effective and cost-effective alternative for all patients. Among available alternatives for patients with genotype 3, sofosbuvir in combination with peginterferon and ribavirin was the most cost-effective alternative, although the combination of daclatasvir and sofosbuvir was somewhat more effective.ConclusionsFor each of the hepatitis C genotypes 1, 2 and 3, there were combinations of DAAs that were cost effective in a Norwegian setting. As a result of recent tender negotiations in Norway, treating all diagnosed patients with hepatitis C with the most cost-effective DAAs will result in lower total expenditure on these medications compared with 2015.

Travel-associated gonorrhoea in four Nordic countries, 2008 to 2013

Travel may be associated with a higher risk of gonorrhoea and infection by antibiotic-resistant strains. The objective of this study was to estimate the risk for gonorrhoea among travellers from four Nordic European countries using surveillance data and to identify at-risk travellers to help target interventions. We retrieved gonorrhoea surveillance data from Denmark, Finland, Norway and Sweden and tourism denominator data from the Statistical Office of the European Union. A travel-associated case of gonorrhoea was defined as one for which the reported country of infection differed from the reporting country. During 2008−2013, the four countries reported 3,224 travel-associated gonorrhoea cases, of which 53% were among individuals below 35 years of age. The overall risk associated with travel abroad was 2.4 cases per million nights abroad. The highest risk was observed with travel to Asia (9.4). Cases more likely to be reported as travel-associated were: males, heterosexuals of both sexes, people older than 65 years, and foreign-born individuals. More effective interventions targeting young adults and other at-risk groups are needed. The use of travel-planning websites and social media should be explored further.

Modelling the burden of hepatitis C infection among people who inject drugs in Norway, 1973–2030

BackgroundLack of Hepatitis C virus (HCV) incidence data in (Norwegian) high-risk groups impedes the ability to make informed decisions on prevention measures. Thus we rely on modelling to estimate the incidence and burden of HCV infections.MethodsWe constructed a compartmental model for HCV infections in Norway among active and former people who inject drugs (PWIDs). We based yearly transition rates on literature. The model was fitted to absolute numbers of hepatitis C associated cirrhosis, hepatocellular carcinoma (HCC) and death from national data sources (2000–2013). We estimated the number (95%CI) of HCV infections, cirrhosis, HCC and death and disability adjusted life years (DALYs) due to HCV infections in Norway, 1973–2030. We assumed treatment rates in the projected period were similar to those in 2013.ResultsThe estimated proportion of chronic HCV (including those with cirrhosis and HCC) among PWIDs was stable from 2000 (49%; 4441/9108) to 2013 (43%; 3667/8587). We estimated that the incidence of HCV among PWIDs was 381 new infections in 2015. The estimated number of people with cirrhosis, HCC, and liver transplant was predicted to increase until 2022 (1537 people). DALYs among active PWIDs estimated to peak in 2006 (3480 DALYs) and decrease to 1870 DALYs in 2030. Chronic HCV infection contributes most to the total burden of HCV infection, and peaks at 1917 DALYs (52%) in 2007. The burden of HCV related to PWID increased until 2006 with 81/100,000 DALYs inhabitants and decreased to 68/100,000 DALYs in 2015.ConclusionThe burden of HCV associated with injecting drug use is considerable, with chronic HCV infection contributing most to the total burden. This model can be used to estimate the impact of different interventions on the HCV burden in Norway and to perform cost-benefit analyses of various public health measures.