Invasive pneumococcal and meningococcal disease: association with influenza virus and respiratory syncytial virus activity?

Few studies have examined the relationship between viral activity and bacterial invasive disease, considering both influenza virus and respiratory syncytial virus (RSV). This study aimed to assess the potential relationship between invasive pneumococcal disease (IPD), meningococcal disease (MD), and influenza virus and RSV activity in The Netherlands. Correlations were determined between population-based data on IPD and MD during 1997-2003 and influenza virus and RSV surveillance data. Incidence rate ratios of disease during periods of high influenza virus and RSV activity over the peri-seasonal and summer baseline periods were calculated. The analyses comprised 7266 and 3072 cases of IPD and MD. When data from all seasons were included, the occurrence of pneumococcal bacteraemia and MD correlated significantly with influenza virus and RSV activity both in children and adults. Periods of increased influenza virus and RSV activity showed higher rates of pneumococcal bacteraemia in older children and adults than the peri-season period. Rates of MD in children were also higher during periods of increased influenza virus activity; the same appeared true for MD in older children during periods of increased RSV activity. Although no causal relationship may be inferred from these data, they support a role for influenza virus and RSV in the pathogenesis of IPD and MD.     

Araçatuba virus: a vaccinialike virus associated with infection in humans and cattle

We describe a vaccinialike virus, Araçatuba virus, associated with a cowpoxlike outbreak in a dairy herd and a related case of human infection. Diagnosis was based on virus growth characteristics, electron microscopy, and molecular biology techniques. Molecular characterization of the virus was done by using polymerase chain reaction amplification, cloning, and DNA sequencing of conserved orthopoxvirus genes such as the vaccinia growth factor (VGF), thymidine kinase (TK), and hemagglutinin. We used VGF-homologous and TK gene nucleotide sequences to construct a phylogenetic tree for comparison with other poxviruses. Gene sequences showed 99% homology with vaccinia virus genes and were clustered together with the isolated virus in the phylogenetic tree. Araçatuba virus is very similar to Cantagalo virus, showing the same signature deletion in the gene. Araçatuba virus could be a novel vaccinialike virus or could represent the spread of Cantagalo virus.     

Should we use Palivizumab immunoprophylaxis for infants against respiratory syncytial virus? – a cost-utility analysis

Background

Passive immunization against RSV (Respiratory Syncytial Virus) is given in most western countries (including Israel) to infants of high risk groups such as premature babies, and infants with Congenital Heart Disease or Congenital Lung Disease. However, immunoprophylaxis costs are extremely high ($2800–$4200 per infant). Using cost-utility analysis criteria, we evaluate whether it is justified to expand, continue or restrict nationwide immunoprophylaxis using palivizumab of high risk infants against RSV.

Methods

Epidemiological, demographic, health service utilisation and economic data were integrated from primary (National Hospitalization Data, etc.) and secondary data sources (ie: from published articles) into a spread-sheet to calculate the cost per averted disability-adjusted life year (DALY) of vaccinating various infant risk groups. Costs of intervention included antibody plus administration costs. Treatment savings and DALYs averted were estimated from applying vaccine efficacy data to relative risks of being hospitalised and treated for RSV, including possible long-term sequelae like asthma and wheezing.

Results

For all the groups RSV immunoprophylaxis is clearly not cost effective as its cost per averted DALY exceeds the $105,986 guideline representing thrice the per capita Gross Domestic Product. Vaccine price would have to fall by 48.1% in order to justify vaccinating Congenital Heart Disease or Congenital Lung Disease risk groups respectively on pure cost-effectiveness grounds. For premature babies of <?29 weeks, 29–32 and 33–36 weeks gestation, decreases of 36.8%, 54.5% and 83.3% respectively in vaccine price are required.

Conclusions

Based solely on cost-utility analysis, at current price levels it is difficult to justify the current indications for passive vaccination with Palivizumab against RSV. However, if the manufacturers would reduce the price by 54.5% then it would be cost-effective to vaccinate the Congenital Heart Disease or Congenital Lung Disease risk groups as well as premature babies born before the 33rd week of gestation.

     

GB virus infection: a silent anti-HIV panacea within?

The GB virus (GBV)/hepatitis G virus is a member of the Flaviviridae family and belongs to the hepatitis group of viruses transmitted parenterally, common among intravenous drug users. The strong association between GBV and HIV infection suggests that the two viruses may share similar epidemiological and transmission features. GBV infection is widely believed to prolong HIV disease progression as well as decreasing the HIV viral load and increasing the CD4(+) T-cell level. GBV-driven anti-E2 antibodies have been shown to inhibit HIV replication in vitro. Preliminary studies also suggest that GBV infection of peripheral blood mononuclear cells leads to increased production of beta-chemokines, which may explain the in vitro inhibitory effects and warrants further studies. With sufficient knowledge of resistance patterns studied in tropical south India, researchers are now keen to study the competitive interactions between GBV-induced chemokines and HIV ligands to bind CCR5.     

Prevalence of hepatitis A virus infection in sewage plant workers of Central Italy: is indication for vaccination justified?

Prevalence of antibodies to hepatitis A virus (HAV) was studied in a group of 65 sewage plant workers living in Tuscany, Central Italy. In order to evaluate the effect of several confounders (age, place of birth, income, educational degree, sea-food consumption, etc.), subjects under study were matched with 160 other workers residing in the same area. Anti-HAV was detected in about 51% of sewage workers and 44% of other employees. The difference was not statistically significant. Both univariate and multivariate analysis showed that the main variables related to previous HAV infection were increasing age (P<0.001), birth in Southern Italy (P<0.01) and lower educational degree (P<0.001). Although other studies in Northern and Central Europe showed a slightly higher risk of infection in sewage workers versus general population, lack of evidence of occupational risk in Italy might be explained by the relative importance of a higher degree of viral circulation in the past. The changing epidemiology of HAV infection in Italy with increasing numbers of susceptibles in adults and the potential occupational risk suggest that the present indication to immunize sewage plant workers against hepatitis A should be maintained.     

Can respiratory syncytial virus etiology be diagnosed clinically? A hospital-based case-control study in children under two years of age

An unmatched, hospital-based case–control study was performed, to determine, whether respiratory syncytial virus (RSV) etiology in hospitalized young children can be predicted clinically. Children under 2 years of age admitted with a lower respiratory tract infection in three hospitals in northern Germany were included (one tertiary and two secondary centers). Cases were children tested positive for RSV by multiplex RT-PCR. One control group consisted of children tested negative for RSV in the multiplex-RT-PCR and a second control group consisted of patients in whom no PCR was done. A weighted backward stepwise logistic regression model was applied for multivariate analysis. RSV-etiology could be predicted with a sensitivity of 72.8% and a specificity of 73.2%. Young age, disease entity – pneumonia or bronchiolitis, center, intercostal retractions, absence of an underlying condition, low level of C-reactive protein, short duration of symptoms (all on admission), prematurity and epidemiologic year were predictive; anatomical infiltrates and wheezing were not. Pathogen specific diagnosis is necessary for individual therapy, allocation in observational studies or treatment trials and for surveillance of airway infections in children, since the positive predictive value is too low for an accurate diagnosis and decision making. Multivariate techniques are effective tools in complex clinical research for deconfounding.     

Is endemic hepatitis E infection present in developed countries?--Accumulating information about the hepatitis E virus and hepatitis E infection

There are several new data on the acute viral hepatitis particularly on infectious non-A-non-C hepatitis viruses. The hepatitis E virus infection was originally thought to be limited only for certain geographic areas and humans. Recently, it has been demonstrated the genetic diversity and worldwide distribution of hepatitis E virus in human population, as well as, the circulation of the virus in many species of animals. It is evident, that hepatitis E virus can spread by fecally contaminated water (waterborne transmission), by meat of infected animals (food-borne transmission), by animal-human contact (zoonotic transmission), and even by transfusion (blood-borne transmission). The frequency of hepatitis E virus infections among the acute hepatitis cases with unknown origin is supposed to be more than 10%. In the differential diagnosis of hepatitis, possible hepatitis E virus infection must be now taken into account even in those areas and countries, like in Hungary, where the infection was previously thought to be non-endemic. To confirm the clinical diagnosis of hepatitis E virus infection, virus specific ELISA and molecular methods are now available. In the near future, a molecular epidemiological study will be organized for the detection of hepatitis E virus in Hungary in collaboration with 9 European countries.--This review covers all aspects of the hepatitis E virus infection including the characteristics and transmission of the etiological agent, the clinical symptoms, its epidemiology, laboratory diagnosis, and some possible control measures.     

Risk factors for measles virus infection and susceptibility in persons aged 15 years and older in China: A multi-site case-control study, 2012–2013

IntroductionEndemic measles persists in China, despite >95% reported coverage of two measles-containing vaccine doses and nationwide campaign that vaccinated >100 million children in 2010. An increasing proportion of infections now occur among adults and there is concern that persistent susceptibility in adults is an obstacle to measles elimination in China. We performed a case-control study in six Chinese provinces between January 2012 to June 2013 to identify risk factors for measles virus infection and susceptibility among adults.MethodsPersons ≥15 years old with laboratory-confirmed measles were age and neighborhood matched with three controls. Controls had blood specimens collected to determine their measles IgG serostatus. We interviewed case-patients and controls about potential risk factors for measles virus infection and susceptibility. Unadjusted and adjusted matched odds ratios and 95% confidence intervals (CIs) were calculated via conditional logistic regression. We calculated attributable fractions for infection for risk factors that could be interpreted as causal.Results899 cases and 2498 controls were enrolled. Among controls, 165 (6.6%) were seronegative for measles IgG indicating persistent susceptibility to infection. In multivariable analysis, hospital visit and travel outside the prefecture in the prior 1–3 weeks were significant risk factors for measles virus infection. Occupation and reluctance to accept measles vaccination were significant risk factors for measles susceptibility. The calculated attributable fraction of measles cases from hospital visitation was 28.6% (95% CI: 20.6–38.8%).ConclusionsExposure to a healthcare facility was the largest risk factor for measles virus infection in adults in China. Improved adherence to hospital infection control practices could reduce risk of ongoing measles virus transmission and increase the likelihood of achieving and sustaining measles elimination in China. The use of control groups stratified by serological status identified distinct risk factors for measles virus infection and susceptibility among adults.     

Non-Digestible Oligosaccharides: A Novel Treatment for Respiratory Infections?

Emerging antimicrobial resistance in respiratory infections requires novel intervention strategies. Non-digestible oligosaccharides (NDOs) are a diverse group of carbohydrates with broad protective effects. In addition to promoting the colonization of beneficial gut microbiota and maintaining the intestinal homeostasis, NDOs act as decoy receptors, effectively blocking the attachment of pathogens on host cells. NDOs also function as a bacteriostatic agent, inhibiting the growth of specific pathogenic bacteria. Based on this fact, NDOs potentiate the actions of antimicrobial drugs. Therefore, there is an increasing interest in characterizing the anti-infective properties of NDOs. This focused review provides insights into the mechanisms by which representative NDOs may suppress respiratory infections by targeting pathogens and host cells. We summarized the most interesting mechanisms of NDOs, including maintenance of gut microbiota homeostasis, interference with TLR-mediated signaling, anti-oxidative effects and bacterial toxin neutralization, bacteriostatic and bactericidal effects, and anti-adhesion or anti-invasive properties. A detailed understanding of anti-infective mechanisms of NDOs against respiratory pathogens may contribute to the development of add-on therapy or alternatives to antimicrobials.     

Hepatitis A virus in surface water in South Africa: what are the risks?

The aim of this study was to assess the potential risk of infection constituted by HAV to persons using surface dam and river water for domestic and recreational purposes. It estimates the potential risk using a deterministic exponential risk assessment model with mean values and conservative assumptions. Hepatitis A virus was detected in 17.5% of river and 14.9% of dam water samples tested. The number of indicator organisms in these sources exceeded drinking and recreational water quality guidelines set by the United States Environmental Protection Agency (US EPA), indicating possible health risks to recreational water users. Based on the available data and taking all the assumptions into consideration, the probability of infection (P_inf) to the higher socio-economic population using the river water for recreational purposes was 1.1 × 10^-3 per day and 3.3 × 10^-1 per annum if 100 ml was ingested per day. For recreation in the dam water the P_inf value was 1.2 × 10^-4 per day and 4.2 × 10^-2 per annum. For the lower socio-economic population, risk values for drinking purposes (2 L day^-1) were ten-fold greater. These surface waters therefore did not conform to the US EPA guidelines of 1 infection per 10,000 consumers per year for drinking water or eight gastrointestinal illnesses per 1,000 bathers per day in environmental waters used for recreational purposes. This is the first risk assessment study addressing the risk of infection by HAV in surface water to different socio-economic populations in South Africa.     

Hepatitis A virus in surface water in South Africa: what are the risks?

The aim of this study was to assess the potential risk of infection constituted by HAV to persons using surface dam and river water for domestic and recreational purposes. It estimates the potential risk using a deterministic exponential risk assessment model with mean values and conservative assumptions. Hepatitis A virus was detected in 17.5% of river and 14.9% of dam water samples tested. The number of indicator organisms in these sources exceeded drinking and recreational water quality guidelines set by the United States Environmental Protection Agency (US EPA), indicating possible health risks to recreational water users. Based on the available data and taking all the assumptions into consideration, the probability of infection (Pinf) to the higher socio-economic population using the river water for recreational purposes was 1.1 x 10(-3) per day and 3.3 x 10(-1) per annum if 100 ml was ingested per day. For recreation in the dam water the Pinf value was 1.2 x 10(-4) per day and 4.2 x 10(-2) per annum. For the lower socio-economic population, risk values for drinking purposes (2 L day(-1)) were ten-fold greater. These surface waters therefore did not conform to the US EPA guidelines of 1 infection per 10,000 consumers per year for drinking water or eight gastrointestinal illnesses per 1,000 bathers per day in environmental waters used for recreational purposes. This is the first risk assessment study addressing the risk of infection by HAV in surface water to different socio-economic populations in South Africa.     

Melioidosis: an emerging infection in Taiwan?

From January 1982 to May 2000, 17 infections caused by Burkholderia pseudomallei were diagnosed in 15 patients in Taiwan; almost all the infections were diagnosed from 1994 to May 2000. Of the 15 patients, 9 (60%) had underlying diseases, and 10 (67%) had bacteremic pneumonia. Thirteen (76%) episodes of infection were considered indigenous. Four patients died of melioidosis. Seventeen B. pseudomallei isolates, recovered from eight patients from November 1996 to May 2000, were analyzed to determine their in vitro susceptibilities to 14 antimicrobial agents, cellular fatty acid and biochemical reaction profiles, and randomly amplified polymorphic DNA patterns. Eight strains (highly related isolates) were identified. All isolates were arabinose non-assimilators and were susceptible to amoxicillin-clavulanate, piperacillin-tazobactam, imipenem, and meropenem. No spread of the strain was documented.     

Hepatitis A: who in NSW is most at risk of infection?

The incidence of hepatitis A in NSW has declined in recent years, but the relative importance of risk factors remains unclear. METHODS: We analysed case data from the NSW Notifiable Diseases Database from 1991 to 2006. RESULTS: Hepatitis A notification rates fell from 18.9 to 1.4 cases per 100 000 between 1991 and 2006. International travel to endemic areas was the likely exposure for 50 per cent of cases between 2002 and 2006. Rates were five times higher in travellers born in countries where hepatitis A is endemic compared with those born in Australia. CONCLUSION: Travellers born in endemic countries should be carefully assessed for vaccination before departure.     

Diet and Respiratory Infections: Specific or Generalized Associations?

Background: Based on our recently reported associations between specific dietary behaviors and the risk of COVID-19 infection in the UK Biobank (UKB) cohort, we further investigate whether these associations are specific to COVID-19 or extend to other respiratory infections. Methods: Pneumonia and influenza diagnoses were retrieved from hospital and death record data linked to the UKB. Baseline, self-reported (2006–2010) dietary behaviors included being breastfed as a baby and intakes of coffee, tea, oily fish, processed meat, red meat (unprocessed), fruit, and vegetables. Logistic regression estimated the odds of pneumonia/influenza from baseline to 31 December 2019 with each dietary component, adjusting for baseline socio-demographic factors, medical history, and other lifestyle behaviors. We considered effect modification by sex and genetic factors related to pneumonia, COVID-19, and caffeine metabolism. Results: Of 470,853 UKB participants, 4.0% had pneumonia and 0.2% had influenza during follow up. Increased consumption of coffee, tea, oily fish, and fruit at baseline were significantly and independently associated with a lower risk of future pneumonia events. Increased consumption of red meat was associated with a significantly higher risk. After multivariable adjustment, the odds of pneumonia (p ≤ 0.001 for all) were lower by 6–9% when consuming 1–3 cups of coffee/day (vs. <1 cup/day), 8–11% when consuming 1+ cups of tea/day (vs. <1 cup/day), 10–12% when consuming oily fish in higher quartiles (vs. the lowest quartile—Q1), and 9–14% when consuming fruit in higher quartiles (vs. Q1); it was 9% higher when consuming red meat in the fourth quartile (vs. Q1). Similar patterns of associations were observed for influenza but only associations with tea and oily fish met statistical significance. The association between fruit and pneumonia risk was stronger in women than in men (p = 0.001 for interaction). Conclusions: In the UKB, consumption of coffee, tea, oily fish, and fruit were favorably associated with incident pneumonia/influenza and red meat was adversely associated. Findings for coffee parallel those we reported previously for COVID-19 infection, while other findings are specific to these more common respiratory infections.