Evaluation of undetected cases during the COVID-19 epidemic in Austria.

BACKGROUND: Knowing the number of undetected cases of COVID-19 is important for a better understanding of the spread of the disease. This study analyses the temporal dynamic of detected vs. undetected cases to provide guidance for the interpretation of prevalence studies performed with PCR or antibody tests to estimate the detection rate. METHODS: We used an agent-based model to evaluate assumptions on the detection probability ranging from 0.1 to 0.9. For each general detection probability, we derived age-dependent detection probabilities and calibrated the model to reproduce the epidemic wave of COVID-19 in Austria from March 2020 to June 2020. We categorized infected individuals into presymptomatic, symptomatic unconfirmed, confirmed and never detected to observe the simulated dynamic of the detected and undetected cases. RESULTS: The calculation of the age-dependent detection probability ruled values lower than 0.4 as most likely. Furthermore, the proportion of undetected cases depends strongly on the dynamic of the epidemic wave: during the initial upswing, the undetected cases account for a major part of all infected individuals, whereas their share decreases around the peak of the confirmed cases. CONCLUSIONS: The results of prevalence studies performed to determine the detection rate of COVID-19 patients should always be interpreted with regard to the current dynamic of the epidemic wave. Applying the method proposed in our analysis, the prevalence study performed in Austria in April 2020 could indicate a detection rate of 0.13, instead of the prevalent ratio of 0.29 between detected and estimated undetected cases at that time.

Use of DALYs in economic analyses on interventions for infectious diseases: a systematic review.

A systematic literature review was performed on full economic evaluations of infectious disease interventions using disability-adjusted life years (DALY) as outcome measure. The search was limited to the period between 1994 and September 2011 and conducted in Medline, SciSearch and EMBASE databases. We included 154 studies, mostly targeting HIV/AIDS and malaria with most conducted for African countries (40%) and <10% in high-income countries. Third-payer perspective was applied in 29% of the studies, 25% used the societal perspective and 12% used both. Only 16% of the studies took indirect effects (i.e. herd immunity) of interventions into account. Intervention, direct healthcare and indirect non-healthcare costs were taken into account in respectively 100%, 81% and 36% of the studies. The majority of the studies followed the Global Burden of Disease method for DALY estimations, but most studies deviated from WHO cost-effectiveness guidelines. Better adherence to freely accessible guidelines will improve generalizability between full economic evaluations.

Cost-effectiveness of primary HPV screening for cervical cancer in Germany--a decision analysis.

OBJECTIVES: To systematically evaluate the long-term effectiveness and cost-effectiveness of HPV-based primary cervical cancer screening in the German health care context using a decision-analysis approach. METHODS: A Markov-model for HPV-infection and cervical cancer was developed for the German health care context, and applied to evaluate various screening strategies that differ by screening interval and test algorithms, including HPV-testing alone or in combination with cytology. German clinical, epidemiological, and economic data, and test accuracy data from international meta-analyses were used. Outcomes predicted included the reduction in cervical cancer cases and deaths, life expectancy and discounted incremental cost-effectiveness ratios (ICER). The analysis was performed from the perspective of the healthcare system adopting a 3% annual discount rate for costs and outcomes. Extensive sensitivity analyses were performed. RESULTS: HPV-based screening is more effective than cytology alone. It results in a 71-97% reduction in cervical cancer cases as compared to 53-93% for cytology alone. The ICER range from 2600 Euro/LYG (cytology, 5-year-interval) to 155,500 Euro/LYG (annual HPV-testing starting at age 30 years, cytology age 20-29 years). Annual cytology alone, the current recommended screening strategy in Germany, is dominated by HPV-strategies. Increasing the age at screening initiation from 20 to 25 years does not result in a relevant loss in effectiveness but results in lower costs. CONCLUSIONS: Based on our analyses, HPV-based cervical cancer screening is more effective than cytology alone and could be cost-effective if performed at intervals of two years or longer. In the German context, an optimal screening strategy may be biennial HPV screening starting at age 30 years preceded by biennial cytology for women aged 25-29 years. Longer screening intervals may be considered in low-risk women with good screening adherence and in populations with low HPV-incidence.

Benefit, risks and cost-effectiveness of screening for abdominal aortic aneurysm.

PURPOSE: Abdominal aortic aneurysms (AAA) cause a considerable number of deaths. A ruptured AAA is associated with a mortality rate of 80%. The purpose of this study was to summarize the current evidence from published health economic models for the long-term effectiveness and cost-effectiveness of screening programs for AAA. MATERIALS AND METHODS: Medical, economic and health technology assessment (HTA) databases were systematically searched for cost-effectiveness models up to October 2007. Only models with a lifetime time horizon of evaluating AAA screening in men over 65 years were included in the review. Study data were extracted, standardized and summarized in evidence tables and cost-effectiveness plots. RESULTS: We reviewed 8 cost-effectiveness models published between 1993 and 2007 comparing AAA screening and lack of screening in men over 60. One model yielded a loss of life-years at additional costs. The remaining seven models yielded gains in life expectancy ranging from 0.02 to 0.28LYs. Gains in quality-adjusted life expectancy reported by six of the seven models ranged from 0.015 to 0.059 QALYs. Incremental costs ranged from 96 to 721 Euros. Incremental cost-effectiveness ratios (ICER) ranged from 1443 to 13 299 Euros per LY or QALY gained. CONCLUSION: Based on our analysis, the introduction of a screening program to identify AAA will probably gain additional life years and quality of life at acceptable extra costs. The target population for a screening program should be men 65 years and older.

Long-term effectiveness and cost-effectiveness of antiviral treatment in hepatitis C.

We systematically reviewed the evidence for long-term effectiveness and cost-effectiveness of antiviral treatment in patients with chronic hepatitis C. We performed a systematic literature search on the long-term effectiveness and cost-effectiveness of AVT in hepatitis C (1990-March 2007), and included health technology assessment (HTA) reports, systematic reviews, long-term clinical trials, economic studies conducted alongside clinical trials and decision-analytic modelling studies. All costs were converted to 2005euro. Antiviral therapy with peginterferon plus ribavirin in treatment-naïve patients with chronic hepatitis C was the most effective (3.6-4.7 life years gained [LYG]) treatment and was reasonably cost-effective (cost-saving to 84 700euro/quality adjusted life years [QALY]) when compared to interferon plus ribavirin. Some results also suggest cost-effectiveness (below 8400euro/(QALY) of re-treatment in nonresponders/relapsers. Results for patients with persistently normal alanine aminotransferase (ALT) levels or with special co-morbidities (e.g. HIV) or risk profiles were rare. We conclude that antiviral therapy may prolong life, improve long-term health-related quality-of-life and be reasonably cost-effective in treatment-naïve patients with chronic hepatitis C as well as in former relapsers/nonresponders. Further research is needed in patients with specific co-morbidities or risk profiles.

Epidemiological and clinical features of travel-associated cryptosporidiosis.

Data concerning the clinical and epidemiological features of travel-associated cryptosporidiosis are lacking. In order to investigate the impact of this disease on travellers' health, a retrospective study was conducted at the Institute of Tropical Medicine, Berlin. In total, 57 cryptosporidial infections were identified between 2000 and 2004, resulting in a prevalence of 2.9% in patients with travel-associated diarrhoea. Travel to south-central Asia, especially India, was associated with a higher prevalence of infection than was travel to other destinations. Clinically, the disease resembled giardiasis, but fever and arthralgias seemed to occur more frequently.

Malaria prophylaxis policy for travellers from Europe to the Indian Subcontinent.

Analysis of malaria imported into eight European countries from the Indian Sub-continent (ISC) (India, Pakistan, Bangladesh and Sri Lanka) led to a consensus statement on the use of chemoprophylaxis within TropNetEurop. The proportion of cases from the ISC in 2004 ranged from 1.4%-4.6% of total imported cases. Plasmodium falciparum cases reported from the eight countries was only 23 (13% of all cases from the region). Total malaria reports between 1999-2004 fell from 317 to 180. The risk of malaria in UK residents visiting the region was > 1 case per 1,000 years exposed. The group recommended non-selective prescribing of chemoprophylaxis for visitors to India, Pakistan, Bangladesh and Sri Lanka should be dropped.

Imported leishmaniasis in Germany 2001-2004: data of the SIMPID surveillance network.

Leishmaniasis is a rare, non-notifiable disease in Germany. Epidemiological and clinical data, therefore, are scarce. Most infections seen in Germany are contracted outside the country. The German surveillance network for imported infectious diseases (Surveillance Importierter Infektionen in Deutschland, or SIPMID) recorded 42 cases of imported leishmaniasis (16 visceral, 23 cutaneous, and 3 mucocutaneous) from January 2001 to June 2004. Although most infections were acquired in European Mediterranean countries, the risk of infection was highest for travelers to Latin America. HIV coinfection was observed significantly more often in patients with visceral leishmaniasis than in patients with cutaneous/mucocutaneous leishmaniasis (31 vs. 4%, p=0.02). The median time to a definitive diagnosis was 85 days in cases of visceral leishmaniasis and 61 days in cases of cutaneous/mucocutaneous leishmaniasis, reflecting the unfamiliarity of German physicians with leishmanial infections. Visceral leishmaniasis was treated most frequently with amphotericin B, whereas cutaneous/mucocutaneous leishmaniasis was treated with a variety of local and systemic therapies. The findings presented here should serve to increase awareness as well as improve clinical management of leishmaniasis in Germany.

Epidemiology and clinical features of vivax malaria imported to Europe: sentinel surveillance data from TropNetEurop.

BACKGROUND: Plasmodium vivax is the second most common species among malaria patients diagnosed in Europe, but epidemiological and clinical data on imported P. vivax malaria are limited. The TropNetEurop surveillance network has monitored the importation of vivax malaria into Europe since 1999. OBJECTIVES: To present epidemiological and clinical data on imported P. vivax malaria collected at European level. MATERIAL AND METHODS: Data of primary cases of P. vivax malaria reported between January 1999 and September 2003 were analysed, focusing on disease frequency, patient characteristics, place of infection, course of disease, treatment and differences between network-member countries. RESULTS: Within the surveillance period 4,801 cases of imported malaria were reported. 618 (12.9%) were attributed to P. vivax. European travellers and immigrants were the largest patient groups, but their proportion varied among the reporting countries. The main regions of infection in descending order were the Indian subcontinent, Indonesia, South America and Western and Eastern Africa, as a group accounting for more than 60% of the cases. Regular use of malaria chemoprophylaxis was reported by 118 patients. With 86 (inter-quartile range 41-158) versus 31 days (inter-quartile range 4-133) the median symptom onset was significantly delayed in patients with chemoprophylaxis (p < 0.0001). Common complaints were fever, headache, fatigue, and musculo-skeletal symptoms. All patients survived and severe clinical complications were rare. Hospitalization was provided for 60% and primaquine treatment administered to 83.8% of the patients, but frequencies varied strongly among reporting countries. CONCLUSIONS: TropNetEurop data can contribute to the harmonization of European treatment policies.

Imported schistosomiasis in Europe: sentinel surveillance data from TropNetEurop.

BACKGROUND: Schistosomiasis is a major parasitic disease, increasingly imported into temperate climates by immigrants from and travelers to endemic areas. METHOD: To generate valid data on imported infectious diseases to Europe and to recognize trends over time, the European Network on Imported Infectious Diseases Surveillance (TropNetEurop) was founded in 1999. Three hundred and thirty-three reports of schistosomiasis were analyzed for epidemiologic and clinical features. RESULTS: Male patients accounted for 64% of all cases. The average age of all patients was 29.5 years. The majority of patients were of European origin (53%). Europeans traveled predominantly for tourism (52%). Main reasons for travel for people from endemic areas were immigration and refuge (51%) and visits to relatives and friends (28%). The majority of infections were acquired in Africa; 92 infections were clearly attributable to Schistosoma haematobium, 130 to Schistosoma mansoni, and 4 to Schistosoma intercalatum. Praziquantel was the only treatment used. No deaths were recorded. CONCLUSION: TropNetEurop sentinel provides valuable epidemiologic and clinical data on imported schistosomiasis to Europe.

Age as a risk factor for severe manifestations and fatal outcome of falciparum malaria in European patients: observations from TropNetEurop and SIMPID Surveillance Data.

Previous studies have indicated that age is a risk factor for severe falciparum malaria in nonimmune patients. The objectives of this study were to reevaluate previous findings with a larger sample and to find out how strongly clinical outcomes for elderly patients differ from those for younger patients. Results of adjusted analyses indicated that the risks of death due to falciparum malaria, of experiencing cerebral or severe disease in general, and of hospitalization increased significantly with each decade of life. The case-fatality rate was almost 6 times greater among elderly patients than among younger patients, and cerebral complications occurred 3 times more often among elderly patients. Antimalarial chemoprophylaxis was significantly associated with a lower case-fatality rate and a lower frequency of cerebral complications. Women were more susceptible to cerebral complications than were men. Our study provides evidence that falciparum malaria is more serious in older patients and demonstrates that clinical surveillance networks are capable of providing quality data for investigation of rare events or diseases.

Surveillance of measles-mumps-rubella vaccine-associated aseptic meningitis in Germany.

BACKGROUND: The study objective was to detect any incidence of aseptic meningitis associated with measles-mumps-rubella (MMR) vaccines that would be considered of public health importance subsequent to the introduction of a new MMR vaccine (Priorix). PATIENTS AND METHODS: Adverse drug reaction (ADR) rates were calculated by relating the number of cases to the number of doses of the different MMR vaccines distributed during a 2-year period in Germany. RESULTS: During the 2-year study period 1,575,936 doses of Priorix and 1,907,875 doses of other MMR vaccines were distributed in Germany. There were no confirmed cases of aseptic meningitis associated with MMR vaccination during this period. Thus, the ADR rates (rejectable with 5% alpha error) were lower than 1/525,312 for Priorix and lower than 1/635,958 for other MMR vaccines. CONCLUSION: The safety profile of the Priorix is similar to that of other MMR vaccines used in Germany.

Epidemiology and clinical features of imported dengue fever in Europe: sentinel surveillance data from TropNetEurop.

Travelers have the potential both to acquire and to spread dengue virus infection. The incidence of dengue fever (DF) among European travelers certainly is underestimated, because few centers use standardized diagnostic procedures for febrile patients. In addition, DF is currently not reported in most European public health systems. Surveillance has commenced within the framework of a European Network on Imported Infectious Disease Surveillance (TropNetEurop) to gain information on the quantity and severity of cases of dengue imported into Europe. Descriptions of 294 patients with DF were analyzed for epidemiological information and clinical features. By far the most infections were imported from Asia, which suggests a high risk of DF for travelers to that region. Dengue hemorrhagic fever occurred in 7 patients (2.4%) all of whom recovered. Data reported by member sites of the TropNetEurop can contribute to understanding the epidemiology and clinical characteristics of imported DF.

Gender differences in emotional disability and negative health perception in cardiac patients 6 months after stent implantation.

OBJECTIVES: In this study we evaluate gender differences in affective adaptation and health perception in patients 6 months after stent implantation. BACKGROUND: Assessment of gender-specific behavioral strategies to cope with serious cardiac disease conditions has not been given much attention until now. Preliminary data suggest greater impairments in female patients, which might be of clinical relevance. METHODS: Three hundred seventeen patients were eligible for the 6-month follow-up investigation, 78 (24.6%) of whom were women. The women were significantly older but did not differ from men in their cardiac risk features and treatment procedures. There were no gender differences in prevalence of hypertension, hypercholesterolemia, and family history. Men had a significantly higher prevalence of smoking than women, whereas women had a significantly higher prevalence of diabetes than men. A structured interview and a standardized psychodiagnostic assessment was carried out, which covered domains of affective dysfunction (depression, anxiety, intrusion, and avoidance), vegetative symptoms (sleeping disorders), and parameters of negative health perception. RESULTS: There were no significant gender differences in the prevalence of depressive symptoms. Women exhibited higher mean values of anxiety than men, which did not reach significance. Sleeping disorders were significantly more prevalent in women. The absolute level of being distressed by intrusive thoughts and avoidance behavior related to the severe underlying disease process was low in the total group of patients examined. Measurable gender differences did not emerge. Fifty-one (16.5%) patients exhibited pessimistic anticipation of dire consequences and severe signs of negative health perception (NHP group). There was a trend, although not statistically significant, toward more women being in the NHP group. The distribution of cardiac risk factors, however, was completely balanced in the NHP(+) and NHP(-) patient groups. Objective somatic cardiac disease parameters did not account for the negative health perception. NHP was, however, associated with significantly more prestent angina pectoris (p < 0.040) and poststent angina pectoris (p < 0.0001). High levels of anxiety, depression, and of disturbed sleep also led to a sharp separation between patients with high degrees of an anticipated incapacitation due to the disease process. Univariate regression analysis suggested an effect of female gender on the occurrence of NHP (odds ratio 1. 70; 95% CI 0.88 to 3.25), which was of borderline significance. Control for confounders in a multiple regression model, however, eliminated the gender effect (odds ratio 1.04, 95% CI 0.48 to 2.23). Poststent chest pain (odds ratio 7.75, 95% CI 3.28 to 18.32) and sleeping disorders (odds ratio 1.32, 95% CI 1.16 to 1.51) were identified as the most powerful confounders of the gender-NHP association. CONCLUSION: Contrary to expectation, women were not per se more distressed than men in all areas of adaptation of the midterm course after stent implantation, although the higher levels of anxiety and sleeping disorders in women deserve attention. A considerable proportion of patients exhibited a pessimistic disease perspective independent of their somatic status, which was associated with affective morbidity. The tendency toward more negative health perception in women may be due to their more frequent occurrence of chest pain and sleeping disorders.

[Diagnostic value of glutamate dehydrogenase determination in the dog]. / Diagnostischer Wert der Glutamat-dehydrogenase-Bestimmung beim Hund.

Overproportional GLDH-increase was found to be the most frequently appearing pathological enzyme pattern in canine practice. Thus it could be shown that GLDH deviates, in spite of its mitochondrial localization and greater molecular weight, more frequently and to a higher degree from its reference value than the parameters ALT, AST, AP, GGT and Bilirubin. The results of the study suggest that the liberation of the enzyme is less determined by the intensity than by the intralobular target of the liver insult. Therefore an increase in GLDH-activity should no longer be interpreted as the result of severe liver damage. On the contrary, the enzyme appeared to be the most sensitive indicator for the diagnosis of primary and secondary hepatopathies. The phenomenon of isolated GLDH-increase could be interpreted in almost every disease group as an appearance of the over-proportional increase and can therefore be understood as a serological expression of a slight, perivenous liver affection. Only with effusion patients the enzyme pattern should be regarded as an independent finding, because it has extrahepatic reasons. The induction of the enzyme in cases of diabetes mellitus is discussed.