Eradication of measles: remaining challenges.

Measles virus (MeV) is an aerosol-borne and one of the most contagious pathogenic viruses known. Almost every MeV infection becomes clinically manifest and can lead to serious and even fatal complications, especially under conditions of malnutrition in developing countries, where still 115,000 to 160,000 patients die from measles every year. There is no specific antiviral treatment. In addition, MeV infections cause long-lasting memory B and T cell impairment, predisposing people susceptible to opportunistic infections for years. A rare, but fatal long-term consequence of measles is subacute sclerosing panencephalitis. Fifteen years ago (2001), WHO has launched a programme to eliminate measles by a worldwide vaccination strategy. This is promising, because MeV is a human-specific morbillivirus (i.e. without relevant animal reservoir), safe and potent vaccine viruses are sufficiently produced since decades for common application, and millions of vaccine doses have been used globally without any indications of safety and efficacy issues. Though the prevalence of wild-type MeV infection has decreased by >90 % in Europe, measles is still not eliminated and has even re-emerged with recurrent outbreaks in developed countries, in which effective vaccination programmes had been installed for decades. Here, we discuss the crucial factors for a worldwide elimination of MeV: (1) efficacy of current vaccines, (2) the extremely high contagiosity of MeV demanding a >95 % vaccination rate based on two doses to avoid primary vaccine failure as well as the installation of catch-up vaccination programmes to fill immunity gaps and to achieve herd immunity, (3) the implications of sporadic cases of secondary vaccine failure, (4) organisation, acceptance and drawbacks of modern vaccination campaigns, (5) waning public attention to measles, but increasing concerns from vaccine-associated adverse reactions in societies with high socio-economic standards and (6) clinical, epidemiological and virological surveillance by the use of modern laboratory diagnostics and reporting systems. By consequent implementation of carefully designed epidemiologic and prophylactic measures, it should be possible to eradicate MeV globally out of mankind, as the closely related morbillivirus of rinderpest could be successfully eliminated out of the cattle on a global scale.

Progress in VZV vaccination? Some concerns.

Since 1995, many countries have been aiming to replace the natural immunity against varicella by a vaccine-induced immunity to protect against varicella and herpes zoster. While the frequency of varicella in childhood has been significantly reduced, in future, herpes zoster morbidity might increase in the elderly due to the weaker immunity post-vaccination and the absence of immunity boosting silent reinfections. In countries, where less than 90 % of children are covered by universal vaccination, varicella zoster virus (VZV) infection is not completely eradicated, but might move from childhood to the age of young adults who suffer from more serious complications. A special VZV vaccine against herpes zoster in adults aged >60 years has proven to be effective in many cases, but not all vaccinees. This might lead to problems regarding the acceptance of vaccination and delay rapid antiviral therapy to prevent the post-zosteric neuralgia. An efficacious-inactivated VZV vaccine to protect immunocompromised patients is still missing. VZV vaccines and vaccination strategies have to be optimised to avoid that the quality of life and cost savings from varicella reduction in childhood are offset by more VZV diseases in adults.

Hepatitis delta: on soft paws across Germany.

INTRODUCTION: Globally, more than 350 million people are considered to be chronic carriers of the hepatitis B virus (HBV) infection; thereof, 15-20 million of these individuals are thought to be coinfected with hepatitis delta virus (HDV). The clinical course depends on the mode of transmission; whereas coinfection commonly resolves, superinfection aggravates the disease and progresses to chronicity in over 90 % of the cases, which, again, results in cirrhosis. OBJECTIVE: Although many tests are performed in HBV carriers, data on the prevalence of anti-HDV-IgG in Germany are only rarely available and outdated. Therefore, we retrospectively evaluated the seroprevalence of anti-HDV-IgG from the results of our routine service. MATERIALS AND METHODS: Between January 2000 and October 2011, serum samples from 2,844 patients (carrying hepatitis B surface antigen) admitted to University Hospital Frankfurt am Main, Frankfurt, Germany, were tested for anti-HDV-IgG by enzyme-linked immunosorbent assay (ELISA). RESULTS: The overall seroprevalence of anti-HDV-IgG in the collective of Frankfurt (n = 2,844) is 7.4 % [95 % confidence interval (CI): 6.4-8.4]. The amount of seropositive men (8.3 %, 95 % CI: 6.9-10) significantly exceeds the female proportion (5.7 %, 95 % CI: 4.3-7.5). The rate of seropositivity to anti-HDV-IgG in this collective of Frankfurt reached a maximum in the year 2003 (10.1 %, 95 % CI: 8.9-11.1). The lowest rate was observable in 2004, where 5.4 % were positive to anti-HDV-IgG. CONCLUSION: Of the HBV carriers in Germany, 5-8 % reveal serologic evidence of coinfection with HDV. The vaccination against HBV is the key to prevent HDV infection; therefore, vaccination must strongly be propagated further on.

Case report: risk of virus infection after accidental blood inoculation from a multi-infected AIDS patient.

Infections caused by blood-borne viruses such as hepatitis B and C and the human immunodeficiency virus (HIV) are associated commonly with needlestick injuries, especially in a hospital setting. A prospective investigation was conducted on a medical doctor who suffered an accidental needlestick injury during blood collection from a patient with AIDS. The patient's blood contained 195,000 copies of HIV RNA, 1 × 10(6) IU hepatitis C virus (HCV) RNA, and >10(7) copies of parvovirus B19 DNA per 1 ml plasma. It was positive for cytomegalovirus virus and evidence of a resolved hepatitis B virus (HBV) infection was found. HCV viremia was detected in the physician 15 days later and was not resolved by seroconversion after 57 days. HIV infection was not transmitted, possibly because of the immediate use of anti-HIV prophylactic drugs after exposure. Parvovirus B19 infection was presumably prevented by pre-existing specific antibodies in the patient. Considering that many HIV carriers are coinfected with hepatitis B and C viruses, this case report support the knowledge that the risk of HCV transmission from a patient with AIDS is greater than that of HIV.

[Measles: immunity and vaccination status in Greater Frankfurt on the Main]. / Masern: Immunität und Impfstatus im Grossraum Frankfurt am Main.

BACKGROUND AND OBJECTIVE: The elimination of measles is a goal of the WHO which has not been achieved in Europe yet. As measles is a vaccine-preventable disease and can be eliminated by immunization the Standing Committee on Vaccination (STIKO) has updated the recommendation of measles vaccination. The goal of this study was to evaluate the immune status by serological testing and by raising immunisation status. METHODS: Antibody-testing from the routine diagnostic of the Institute of Medical Virology (Frankfurt/Main) for patients, health care workers and medical students was investigated retrospectively. RESULTS: Overall all significant increase in seropositivity was shown from 64.8 to 86.2 %. Nevertheless immunity gaps still exist in population, especially in persons under 19 years of age. In 1999 80.7 % of the 5-9 year age group and 75.3 % of the 10-19 year age group were seropositive. In 2009 the percentage in these age groups has decreased to 68.2 % and 71.1 % respectively. By obtaining the immunity status of 230 travellers at our vaccination centre immunity gaps have been recognised as well. Only 29.6 % were completely immunized (at least two vaccination). 54.4 % have been vaccinated incomplete and in 16.1 % vaccination status was unknown. CONCLUSION: Our results indicated that measles immunization status and seroprevalence are still not sufficient to achieve the elimination of measles.

Recent publications in medical microbiology and immunology: a retrospective.

A look back is done to some clinical and basic research activities recently published in medical microbiology and immunology. The review covers clinical experiences and in vitro experiments to understand the emergency, pathogenicity, epidemic spread, and vaccine-based prevention of avian and swine-origin flu. Some new developments and concepts in diagnosis, (molecular) epidemiology, and therapy of AIDS, viral hepatitis C, and herpesvirus-associated diseases are outlined. Regulation of immune system has been discussed in a special issue 2010 including some aspects of CNS affections (measles). Mycobacterial infection and its prevention by modern recombinant vaccines have reached new interest, as well as new concepts of vaccination and prophylaxis against several other bacteria. Adaptation to host niches enables immune escape (example brucella) and determines virulence (example N. meningitidis). Chlamydia pneumoniae, previously considered to trigger atherosclerosis, is hypothetically associated to Alzheimer disease, while CMV, another putative trigger of atherosclerosis, gains evidence of oncomodulation in CNS tumor diseases. In terms of globalization, exotic virus infections are increasingly imported from southern countries.

Selection of a highly invasive neuroblastoma cell population through long-term human cytomegalovirus infection.

The human cytomegalovirus (HCMV) is suspected to increase tumour malignancy by infection of cancer and/or stroma cells (oncomodulation). So far, oncomodulatory mechanisms have been attributed to the presence of HCMV and direct action of its gene products on cancer cells. Here, we investigated whether the prolonged presence of HCMV can result in the irreversible selection of a cancer cell population with increased malignancy. The neuroblastoma cell line UKF-NB-4 was long-term (200 passages) infected with the HCMV strain Hi91 (UKF-NB-4(Hi)) before virus eradication using ganciclovir (UKF-NB-4(HiGCV)). Global gene expression profiling of UKF-NB-4, UKF-NB-4(Hi) and UKF-NB-4(HiGCV) cells and subsequent bioinformatic signal transduction pathway analysis revealed clear differences between UKF-NB-4 and UKF-NB-4(Hi), as well as between UKF-NB-4 and UKF-NB-4(HiGCV) cells, but only minor differences between UKF-NB-4(Hi) and UKF-NB-4(HiGCV) cells. Investigation of the expression of a subset of five genes in different chronically HCMV-infected cell lines before and after virus eradication suggested that long-term HCMV infection reproducibly causes specific changes. Array comparative genomic hybridisation showed virtually the same genomic differences for the comparisons UKF-NB-4(Hi)/UKF-NB-4 and UKF-NB-4(HiGCV)/UKF-NB-4. UKF-NB-4(Hi) cells are characterised by an increased invasive potential compared with UKF-NB-4 cells. This phenotype was completely retained in UKF-NB-4(HiGCV) cells. Moreover, there was a substantial overlap in the signal transduction pathways that differed significantly between UKF-NB-4(Hi)/UKF-NB-4(HiGCV) and UKF-NB-4 cells and those differentially regulated between tumour tissues from neuroblastoma patients with favourable or poor outcome. In conclusion, we present the first experimental evidence that long-term HCMV infection can result in the selection of tumour cell populations with enhanced malignancy.

H1N1v at a seroepidemiological glance: is the nightmare over?

When the second wave of pandemic influenza A H1N1v 2009 (H1N1v) emerged in the winter of 2010/2011, public health authorities were afraid of dangerous implications and severe clinical courses again. As further H1N1v waves might appear, achievement of sufficient herd immunity is a matter of urgency. The objective of this study was to determine the seroprevalence of antibodies against H1N1v by hemagglutination-inhibition test (HI) after the second wave. We compared our recent findings with our data obtained after the first pandemic in 2009/2010. Between March and May 2011 we collected serum samples from 600 persons aged 1 to 84 years admitted to University Hospital Frankfurt/Main and analysed the titres of anti-H1N1v by HI. The overall seroprevalence of anti-H1N1v has risen from 36.9% (95% confidence interval (95%CI), 33-41) in unvaccinated persons after the first wave to 57.3% (95%CI, 53.1-61.2) in vaccinated and unvaccinated. The highest rate of seropositivity was detected in the age group of 10-19 years (66%; 95%CI, 55.8-75.2), whereas the lowest was found in the age group 40-59 years (51%; 95%CI, 40.8-61.1). Although seroprevalence has significantly increased, sufficient herd immunity is still not achieved. Therefore, general vaccination programs have to be propagated continuously by public health authorities.

Adaptation of cancer cells from different entities to the MDM2 inhibitor nutlin-3 results in the emergence of p53-mutated multi-drug-resistant cancer cells.

Six p53 wild-type cancer cell lines from infrequently p53-mutated entities (neuroblastoma, rhabdomyosarcoma, and melanoma) were continuously exposed to increasing concentrations of the murine double minute 2 inhibitor nutlin-3, resulting in the emergence of nutlin-3-resistant, p53-mutated sublines displaying a multi-drug resistance phenotype. Only 2 out of 28 sublines adapted to various cytotoxic drugs harboured p53 mutations. Nutlin-3-adapted UKF-NB-3 cells (UKF-NB-3(r)Nutlin(10 µM), harbouring a G245C mutation) were also radiation resistant. Analysis of UKF-NB-3 and UKF-NB-3(r)Nutlin(10 µM) cells by RNA interference experiments and lentiviral transduction of wild-type p53 into p53-mutated UKF-NB-3(r)Nutlin(10 µM) cells revealed that the loss of p53 function contributes to the multi-drug resistance of UKF-NB-3(r)Nutlin(10 µM) cells. Bioinformatics PANTHER pathway analysis based on microarray measurements of mRNA abundance indicated a substantial overlap in the signalling pathways differentially regulated between UKF-NB-3(r)Nutlin(10 µM) and UKF-NB-3 and between UKF-NB-3 and its cisplatin-, doxorubicin-, or vincristine-resistant sublines. Repeated nutlin-3 adaptation of neuroblastoma cells resulted in sublines harbouring various p53 mutations with high frequency. A p53 wild-type single cell-derived UKF-NB-3 clone was adapted to nutlin-3 in independent experiments. Eight out of ten resulting sublines were p53-mutated harbouring six different p53 mutations. This indicates that nutlin-3 induces de novo p53 mutations not initially present in the original cell population. Therefore, nutlin-3-treated cancer patients should be carefully monitored for the emergence of p53-mutated, multi-drug-resistant cells.

[Comparison of seasonal influenza vaccines: composition and properties]. / Saisonale Influenza-Impfstoffe: Zusammensetzung und Eigenschaften.

The influenza virus isolation in embryonated chicken eggs was possible early in 1930er years and allowed the influenza vaccine production. Most influenza vaccines were derived from this, but actually new virus cell culture methods are established. For better tolerability, influenza vaccines include only antigen proportions (split- and subunit vaccines) but with the disadvantage of minor vaccine efficacy. This was compared with the addition of adjuvants. Aluminium salts are used for many decades and still in use to enhance the effect of vaccines. New formulations are MF59, AS03, AS04 or toll- like receptor-agonists. Also virosomal formulations and "ISCOMs"(Immune Stimulating Complexes) are newly designed and compromises enhanced immune reactions. Actually a broad range of various influenza vaccines exist and are available for a very different group of patients (which depends on physical conditions, age, immune status or allergies).

[Diagnostic of neurotropic enteroviruses in children with CSF and/or stool: virus isolation by cell culture or PCR?]. / Enterovirusdiagnostik bei aseptischer Meningitis im Kindesalter mit Liquor und/oder Stuhl: Zellkulturgestützte Virusisolierung oder PCR?

BACKGROUND: Aseptic meningitis in children is most frequently caused by enteroviruses. In clinical setting there arises the question, whether stool samples or cerebrospinal fluid (CSF) are better suited for laboratory diagnosis. METHODS: Between 06/2006 and 03/2010 a total number of 613 specimens (376 CSF [61.4%] and 237 stool [38.6%]) of 613 children (270 female [44.1%] and 343 [55.9%] male) aged 22 days to 15 years were collected and investigated by enterovirus-PCR and by virus isolation in cell culture, respectively. RESULTS: Enterovirus was detected in 35.4% (217/613) of the samples by cell culture and/or PCR. In total, specimens of CSF were significantly (p<0.001) more often positive (59.4%, n=129) for enterovirus than stool (40.6%; n=88). Concerning stool, PCR gained no significant advantage when compared to cell culture (35.4% vs. 27.8%; p=0.08), However, virus isolation in cell culture using CSF samples succeeded significantly PCR (30.1% vs. 13.8%; p<0.001). DISCUSSION: Because of its not-invasive sampling, stool is the preferred specimen in suspicion of aseptic meningitis in pediatric clinic. If only stool is available, PCR as well as cell culture are valuable; on contrary, if CSF is available cell culture is significantly superior to PCR in attaining a positive result.

Assessment of mumps virus-specific antibodies by different serological assays: which test correlates best with mumps immunity?

Mumps is one of the vaccine-preventable childhood diseases and it has not yet been eradicated in Germany. This raises the question as to whether the available mumps vaccines are effective enough to prevent mumps and which antibody test system allows the authentic assigning of mumps-specific immunity. In an attempt to answer this question, we analysed 227 sera samples from medical students of the University Hospital Frankfurt/Main, Germany, using different test systems: indirect immune fluorescence, neutralisation assay, routine ELISA and newly developed immunoassays, which contain the mumps nucleoprotein and the wild-type strain Enders ATCC VR106, respectively. Mumps vaccination coverage of the screened collective amounted to 75.1%, which differs notably from the detected mumps-specific seropositivity rates in the literature (range 53.3% to 82.4%). In contrast, a small group of unvaccinated students had much higher seropositivity rates. Of course, assigned vaccination coverage and calculated seropositivity rates are not effective enough to interrupt the transmission of the mumps virus. The often-occurring mumps outbreaks, some in highly vaccinated populations, may not always demonstrate vaccine failure. The investigation of newly developed test systems and the occurrence of different mumps virus genotypes should also be considered.

Limited prevalence of influenza A/H1N1v antibodies: footprints of the pandemic of 2010.

BACKGROUND: The intention of our investigation was to determine the seroprevalence of H1N1v antibodies after a pandemic by the haemagglutination inhibition (HI) test. We included the serum samples of adults who had not received vaccination against H1N1v. By means of serological footprints, the spread of infection can be investigated. MATERIALS AND METHODS: Between December 2009 and May 2010, we collected 233 serum samples from healthy people aged 1-72 years and analysed the titres of H1N1v antibodies by the use of the HI test. RESULTS: After the pandemic, a seroprevalence of 36.9% was observed. The highest rate of seropositivity was detected in the age group of 10-19 years (60%) and the lowest rate was found in the age group of 30-39 years (22%). The seroprevalence of H1N1v antibodies in females exceeded the rate of positive men (41.5 vs. 31.8%). Almost 70% of the influenza A/H1N1v infections were passed inapparently.

Mutations in the C-terminal region of the HIV-1 reverse transcriptase and their correlation with drug resistance associated mutations and antiviral treatment.

OBJECTIVE: replication of HIV-1 after cell entry is essentially dependent on the reverse transcriptase (RT). Antiretroviral drugs impairing the function of the RT currently aim at the polymerase subunit. One reason for failure of antiretroviral treatment is the evolvement of resistance-associated mutations in the viral genome. For RT inhibitors, almost all identified mutations are located within the polymerase; therefore, general genotyping confines to investigate this subunit. Recently several studies have shown that substitutions within the RNase H and the connection domain increase antiviral drug-resistance in vitro, and some of them are present in patient isolates. AIM: the aim of the present study was to investigate the prevalence of these substitutions and their association with mutations in the polymerase domain arising during antiretroviral treatment. MATERIAL AND METHODS: we performed genotypic analyzes on seventy-four virus isolates derived from treated and untreated patients, followed at the HIV Centre of the Johann Wolfgang Goethe University Hospital (Frankfurt/Main, Germany). We subsequently ana?lysed the different substitutions in the c-terminal region to evaluate whether there were associations with each other, n-terminal substitutions or with antiretroviral treatment. RESULTS: We identified several primer grip substitutions, but almost all of them were located in the connection domain. This is consistent with other in-vivo studies, in which especially the primer grip residues located in the RNase H were unvaried. Furthermore, we identified other substitutions in the connection domain and in the RNase H. Especially E399D seemed to be associated with an antiretroviral treatment and N-terminal resistance-delivering mutations. CONCLUSION: some of the identified substitutions were associated with antiviral treatment and drug resistance-associated mutations. Due to the low prevalence of C-terminal mutations and as only a few of them could be associated with antiviral treatment and N-terminal resistance-delivering mutations, we would not recommend routinely testing of the C-terminal RT region.

Intensification of a failing regimen with zidovudine may cause sustained virologic suppression in the presence of resensitising mutations including K65R.

OBJECTIVES: The reverse transcriptase (RT)-mutation K65R limits further therapeutic options and has been selected by unfavorable RT-combinations, e.g. tenofovir in combination with abacavir and/or didanosine. METHODS: We identified HIV-1 infected patients from a large treatment cohort who experienced virological failure (HIV-1 RNA >1000 copies/mL) with evidence of resistance mutations including the K65R, but without thymidine analogue mutations (TAMs) in genotypic resistance assay. Phenotype was performed from previously collected frozen plasma. The patients were followed for clinical and resistance outcome after treatment intensification with only zidovudine. RESULTS: Five patients had experienced antiretroviral treatment failure on various nucleoside analogue combinations, containing abacavir, didanosine, lamivudine, nevirapine, reverset and/or tenofovir. RT-sequence revealed mutations at position K65R in combination with other non-TAMs. The patients' median viral load prior to zidovudine intensification was 3.551 Log10 (range 3.053-4.681) and despite evidence for resistance to the failing drug regimen, all responded within 4 weeks to undetectable levels (<1.699 Log10 or <50 copies/mL) and remained virologically suppressed during follow-up (20 months through 6.5 years). CONCLUSIONS: In virologically failing patients due to K65R- and other non-thymidine-mutations, simple regimen intensification with zidovudine resulted in sustained HIV-1 suppression. The finding of re-sensitized HIV-1 in patients may be clinically relevant.

Seroepidemiology of parvovirus B19 in the Frankfurt am Main area, Germany: evaluation of risk factors.

BACKGROUND: Parvovirus B 19 is a virus that is distributed by respiratory droplets. It is known to be an initiator of erythema infectiosum (children's fifth disease), with erythroblasts being the target cells of infection. In case of vertically transmission, hydrops fetalis has been documented. OBJECTIVE: Parvovirus B19 seroprevalence was investigated in serum samples routinely collected from patients who had been admitted to the University Hospital in Frankfurt a. M., Germany. Patients were classified in different groups in order to analyze parovirus B19 seroprevalences in terms of risk factors. MATERIALS AND METHODS: Between June 2007 and March 2010, a total of 2,197 serum samples were analyzed for parvovirus B19-immunoglobulin G using an enzyme-linked immunosorbent assay. The study population included six groups of patients, namely, patients suffering from haemophilia, malignant disease, immunodeficiency diseases, common gynecological ailments, pregnant women and children with malignant diseases. RESULTS: Of the 2,197 serum samples, 1,383 contained antibodies to parvovirus B19 (62.9%). The overall seroprevalence in adults (20 to ≥60 years of age) was 71%. Gradually rising prevalences were recorded in children/adolescents with increasing age. We found a positive serostatus in 54.9% of adult patients with malignant disease, in 64.2% of patients with haemophilia (1 to ≥60 years), in 66.7% of patients under immunosuppression with various drugs (1 to ≥60 years) and in 41.7% of oncological patients aged 1-19 years. Of the pregnant women (aged 15-49 years), 71.1% were seropositive. CONCLUSION: The seroprevalence of parvovirus B19 in patients admitted to the University Hospital in Frankfurt a.M. was, on average, lower than that among the general population in Germany. Infection among patients in specific risk groups did not spread more than that in age-matched non-selected patients, with the exception of the group of immunocompromised patients.