Marina Hoehne

Norovirus illness is a global problem: emergence and spread of norovirus GII.4 variants, 2001-2007.

BACKGROUND Noroviruses (NoVs) are the most common cause of viral gastroenteritis. Their high incidence and importance in health care facilities result in a great impact on public health. Studies from around the world describing increasing prevalence have been difficult to compare because of differing nomenclatures for variants of the dominant genotype, GII.4. We studied the global patterns of GII.4 epidemiology in relation to its genetic diversity. METHODS Data from NoV outbreaks with dates of onset from January 2001 through March 2007 were collected from 15 institutions on 5 continents. Partial genome sequences (n=775) were collected, allowing phylogenetic comparison of data from different countries. RESULTS The 15 institutions reported 3098 GII.4 outbreaks, 62% of all reported NoV outbreaks. Eight GII.4 variants were identified. Four had a global distribution--the 1996, 2002, 2004, and 2006b variants. The 2003Asia and 2006a variants caused epidemics, but they were geographically limited. Finally, the 2001 Japan and 2001 Henry variants were found across the world but at low frequencies. CONCLUSIONS NoV epidemics resulted from the global spread of GII.4 strains that evolved under the influence of population immunity. Lineages show notable (and currently unexplained) differences in geographic prevalence. Establishing a global NoV network by which data on strains with the potential to cause pandemics can be rapidly exchanged may lead to improved prevention and intervention strategies.

International Collaborative Study To Compare Reverse Transcriptase PCR Assays for Detection and Genotyping of Noroviruses

ABSTRACT To allow more rapid and internationally standardized assessment of the spread of noroviruses (previously called Norwalk-like viruses [NLVs]) as important food-borne pathogens, harmonization of methods for their detection is needed. Diagnosis of NLVs in clinical diagnostic laboratories is usually performed by reverse transciptase PCR (RT-PCR) assays. In the present study, the performance of five different RT-PCR assays for the detection of NLVs was evaluated in an international collaborative study by five laboratories in five countries with a coded panel of 91 fecal specimens. The assays were tested for their sensitivity, detection limit, and ease of standardization. In total, NLVs could be detected by at least one RT-PCR assay in 69 (84%) of the samples that originally tested positive. Sensitivity ranged from 52 to 73% overall and from 54 to 100% and 58 to 85% for genogroup I and II viruses, respectively. In all, 64% of the false-negative results were obtained with a set of diluted stools (n = 20) that may have lost quality upon storage. Sensitivity was improved when these samples were excluded from analysis. No one single assay stood out as the best, although the p1 assay demonstrated the most satisfactory overall performance. To promote comparability of data, this assay will be recommended for newly starting groups in future collaborative studies.

Major outbreak of hepatitis A associated with orange juice among tourists, Egypt, 2004.

In 2004, a major outbreak of hepatitis A among tourists returning from Egypt involved 351 case-patients from 9 European countries who were infected with a single strain (genotype 1b). The case-control study identified orange juice as the most likely infection vehicle. Vaccination against hepatitis A virus is strongly recommended before travel to disease-endemic areas.

Rotavirus vaccine effectiveness and case-control study on risk factors for breakthrough infections in Germany, 2010-2011.

Background: In the German federal state Mecklenburg-Western Pomerania, routine rotavirus (RV) vaccination in infants has been recommended since 2009. The effectiveness of RV vaccination was investigated after an unexpectedly high number of RV infections in fully vaccinated children occurred. Methods: Intensified RV surveillance was performed in Mecklenburg-Western Pomerania between 2010 and 2011. The screening method was applied to assess vaccine effectiveness (VE) in children up to 24 months after vaccination. To identify risk factors for breakthrough infections, a case-control study and genotyping were conducted in vaccinated and unvaccinated RV-infected children. Results: VE for the prevention of RV infection requiring medical attention or hospitalization was 68% (95% confidence interval [CI]: 61–71) and 80% (95% CI: 77–83), respectively. VE for preventing hospitalization but not medical attention remained stable over 2 years. Vaccinated were less often hospitalized (23%) than unvaccinated RV-infected children (61%; P < 0.001). Breastfeeding (odds ratio, 3.99; 95% CI: 1.92–8.27) and attending daycare (odds ratio, 3.42; 95% CI: 1.64–7.12) were independently associated with breakthrough infections. Genotype G1P[8] was detected more frequently in RotaTeq-vaccinated (44% versus 11%; P < 0.03) and G2P[4] in Rotarix-vaccinated children (42% versus 6%; P < 0.02). Conclusions: RV vaccination protects young children effectively from RV disease and can reduce disease severity. Breastfeeding might impair VE, but further research is needed to identify the critical time window for this interference and to develop appropriate recommendations.

Highly sensitive detection of the group A Rotavirus using Apolipoprotein H-coated ELISA plates compared to quantitative real-time PCR

BackgroundThe principle of a capture ELISA is binding of specific capture antibodies (polyclonal or monoclonal) to the surface of a suitable 96 well plate. These immobilized antibodies are capable of specifically binding a virus present in a clinical sample. Subsequently, the captured virus is detected using a specific detection antibody. The drawback of this method is that a capture ELISA can only function for a single virus captured by the primary antibody. Human Apolipoprotein H (ApoH) or β2-glycoprotein 1 is able to poly-specifically bind viral pathogens. Replacing specific capture antibodies by ApoH should allow poly-specific capture of different viruses that subsequently could be revealed using specific detection antibodies. Thus, using a single capture ELISA format different viruses could be analysed depending on the detection antibody that is applied. In order to demonstrate that this is a valid approach we show detection of group A rotaviruses from stool samples as a proof of principle for a new method of capture ELISA that should also be applicable to other viruses.ResultsStool samples of different circulating common human and potentially zoonotic group A rotavirus strains, which were pretested in commercial EIAs and genotyped by PCR, were tested in parallel in an ApoH-ELISA set-up and by quantitative real-time PCR (qPCR). Several control samples were included in the analysis. The ApoH-ELISA was suitable for the capture of rotavirus-particles and the detection down to 1,000 infectious units (TCID50/ml). Subsets of diagnostic samples of different G- and P-types were tested positive in the ApoH-ELISA in different dilutions. Compared to the qPCR results, the analysis showed high sensitivity, specificity and low cross-reactivity for the ApoH-ELISA, which was confirmed in receiver operating characteristics (ROC) analysis.ConclusionsIn this study the development of a highly sensitive and specific capture ELISA was demonstrated by combining a poly-specific ApoH capture step with specific detection antibodies using group A rotaviruses as an example.

Severe gastroenteritis with secondary fever in a 10-month-old boy

A 10-month-old boy presented in our emergency department n a severely reduced general condition, apathetic and sleepy. He ad non-bloody diarrhea and had been vomiting for two days prior o admission. As medication he did receive dimenhydrinate, which id not improve his symptoms. His mother also had diarrhea at the ame time. Beginning at the evening before admission to our hospial he refused eating and drinking. At 3 am on the day of admission is mother found him in a stuporous state, not reacting properly. onsequently he was brought to the hospital. Until that day the atient had developed regularly and was otherwise well. In the mergency room he did not react much to stimulation and often ell asleep. The examination revealed a heavily inflated abdomen. here was no pain during palpation, no enlargement of liver and pleen, no resistance. The blood results showed reduced blood glucose (25mg/dl), ery low sodium (125mmol/l) and mildly reduced potassium 3.48mmol/l). The white blood cells were increased (WBC 3.420/ l) of which 62% were segmented neutrophils and 3% and neutrophils, the marker of infection C-reactive protein (CrP) as marginally increased (5.6mg/l). The liver enzymes were ignificantly raised (GOT 323U/l, GPT 183U/l, GGT 12U/l) and he blood coagulation was compromised (Quick 50%, INR 1.41, TT 27 s). The creatinine was within normal range (0.37mg/dl). urther blood results revealed high creatinine kinase (972U/l) nd high cortisol (857nmol/l). Further endocrinological workup evealed no abnormalities. Kidney and the thyroid function vales as well as immunoglobulin IgA, IgG and IgM were within ormal range. The initial venous blood gas analysis was mainly ithin normal range: pH 7.36, pCO2 33.1mmHg, pO2 46.6mmHg, icarbonate 18.4mmol/l, base excess−5.9mmol/l. Investigation of