Lymphocytic choriomeningitis,Ljungan and orthopoxvirus seroconversions in patients hospitalized due to acute Puumala hantavirus infection

BackgroundThe emergence and re-emergence of zoonotic and vector-borne diseases are increasing in Europe. Prominent rodent-borne zoonotic viruses include Puumala hantavirus (PUUV; the causative agent of nephropathia epidemica, NE), lymphocytic choriomeningitis virus (LCMV), and orthopoxviruses (OPV). In addition, Ljungan virus (LV) is considered a potentially zoonotic virus.ObjectiveThe aim of this study was to compare clinical picture between acute PUUV patients with and without additional rodent-borne viral infections, to investigate if concurrent infections influence disease severity.Study designWe evaluated seroprevalence of and seroconversions to LCMV, LV and OPV in 116 patients hospitalized for NE. Clinical and laboratory variables were closely monitored during hospital care.ResultsA total of five LCMV, 15 LV, and one OPV seroconversions occurred. NE patients with LCMV seroconversions were younger, and had lower plasma creatinine concentrations and platelet counts than patients without LCMV seroconversions. No differences occurred in clinical or laboratory findings between patients with and without seroconversions to LV and OPV. We report, for the first time, LCMV seroprevalence in Finland, with 8.5% of NE patients seropositive for this virus. Seroprevalences for LV and OPV were 47.8% and 32.4%, respectively.ConclusionCases with LCMV seroconversions were statistically younger, had milder acute kidney injury and more severe thrombocytopenia than patients without LCMV. However, the low number of seroconversion cases precludes firm conclusions. Concurrent LV or OPV infections do not appear to influence clinical picture for NE patients.     

Seroprevalence of West Nile Virus specific IgG and IgM antibodies in North-Western and Western provinces of Zambia

BackgroundWest Nile Virus (WNV) infection has been reported worldwide, including in Africa but its existence in Zambia is unknown. Symptoms for the virus include headache, myalgia, arthralgia and rash.ObjectivesThis study aimed to determine the seroprevalence of WNV and its correlates.MethodsA cross sectional study was conducted in North-Western and Western provinces of Zambia. Samples were subjected to IgG and IgM antibodies testing against WNV. Logistic regression analyses were conducted to determine magnitudes of association.ResultsA total of 3,625 of persons participated in the survey out of which 10.3% had WNV infection. Farmers were 20% (AOR=0.80; 95% CI [0.64, 0.99]) less likely to have infection compared to students. Meanwhile participants who lived in grass roofed houses were 2.97 (AOR=2.97; 95% CI [1.81, 4.88]) times more likely to be infected than those who lived in asbestos roofed houses. IRS was associated with reduced risk of infection (AOR=0.81; 95% CI [0.69, 0.94]). Travelling to Angola was associated with the infection [AOR=1.40; 95% CI [1.09, 1.81].ConclusionSpraying houses with insecticide residual spray would minimize mosquito-man contact. Furthermore, surveillance at the border with Angola should be enhanced in order to reduce importation of the virus into the country.     

Molecular epidemiology of hepatitis B and Delta virus strains that spread in the Mediterranean North East Coast of Tunisia

BackgroundTunisia is classified as an area of middle endemic for hepatitis B virus (HBV) infection, however little is known about hepatitis Delta virus (HDV) infection.ObjectivesThis study aimed to address the prevalence of HDV infection, to identify possible risks factors, and to analyze the genetic diversity of HDV strains that are spreading in Tunisia.Study designA retrospective large-scale study including 1615 HBsAg positive patients, native of the North East coast of Tunisia, recruited from Gastroenterology departments, was conducted. Demographic, epidemiological, ethnical, clinical and biological data were recorded. HBV and HDV serological analyses and DNA and RNA viral load quantification were performed. Genotyping of HBV and HDV strains was performed using nucleotide sequencing followed by phylogenetic analyses.ResultsThe study population included 819 (50.7%) men and 796 (49.3%) women; aged 12–90 years (mean age 41 ± 13 years). A very low prevalence of HDV infection, 2% was observed. No risk factor, except a history of hospitalization for surgery was found. All HDV strains belonged to genotype 1, with a wide distribution within the HDV-1 group. They all share the African amino acid marker, a serine at position 202 of the large Delta protein. HBV genotypes were distributed as follows: HBV/D1 (56.8%), HBV/D7 (40.9%), and HBV/A2 (2.3%).ConclusionTunisia is a low endemic region for HDV infection, due to an efficient policy of HBV infection control. HDV-1 is the sole genotype found, with a high diversity within this group. Further studies are ongoing in order to better characterize and manage the HBV/HDV-infected patients according to the genetic variability of the viral strains.     

Seroprevalence of IgG antibodies against 13 vaccine Streptococcus pneumoniae serotypes in the Netherlands

In this study the seroprevalence of IgG antibodies against 13 vaccine serotypes of the pneumococcus was assessed in the Netherlands. Sera from 7904 persons obtained in a cross-sectional population-based study were analysed. The 13 serotype specific IgG concentrations were assessed simultaneously using a fluorescent bead-based multiplex immuno assay (MIA).Overall, the geometric mean IgG concentrations (GMCs) against the 13 serotypes in unvaccinated individuals increased with age up to 5 years and remained at a plateau thereafter. The data also show that individuals develop antibodies against an increasing number of different serotypes with increasing age. The highest GMCs were found for antibodies directed against serotype 14 and 19F, whereas antibodies against serotypes 4 and 5 had the lowest GMCs. There was no uniform relationship between the occurrence of serotypes causing invasive pneumococcal disease (IPD) and the GMCs against these serotypes. Increased IPD incidence in the elderly did not seem to be the result of a decline in the concentration of IgG antibodies.     

Seroprevalences of hepatitis B virus and hepatitis C virus among participants of an Asian health fair in the Lower Mainland,British Columbia

BACKGROUND:

The seroprevalences of hepatitis B virus (HBV) and hepatitis C virus (HCV) are 0.4% and 0.8%, respectively, in Canada, but varying rates have been reported in different populations.

OBJECTIVES:

To determine the seroprevalences of HBV and HCV among attendees of an Asian health fair in the Lower Mainland, British Columbia, as well as to correlate questionnaire answers regarding vaccination status to serological profiles.

METHODS:

Attendees at an Asian health fair were invited to participate in the present study on a voluntary basis. They provided answers to a questionnaire including ethnicity and vaccination status. Blood was then drawn for HBV and HCV serology. Active HBV was defined as HBV surface antigen (HBsAg) positive while HCV seroprevalence was defined as HCV antibody reactive. Previous exposure to HBV was defined as HBV core antibody (anti-HBc) positive and HBsAg negative. Nonimmunity was defined as anti-HBc negative and HBV surface antibody negative. Only those with correct demographic information matched to serological results were included in the study.

RESULTS:

There were 192 consenting attendees of the fair, of whom 112 were included in the study. Of the participants, 91% were Chinese. Active HBV infection was found in three participants (2.7% [95% CI 0.6% to 7.6%]) and HCV infection was found in two participants (1.8% [95% CI 0.2% to 6.3%]). More than 40% of participants had been previously exposed to HBV (42% [95% CI 33% to 51%]). Almost 20% demonstrated nonimmunity to HBV (19% [95% CI 12% to 27%]). There was significant discordance when questionnaire answers regarding vaccination status were compared with serological profiles.

CONCLUSION:

The seroprevalences of HBV and HCV in this cohort were 2.7% and 1.8%, respectively – higher than nationally reported rates. Our results highlight that the lack of knowledge of HBV infection and vaccination status remains a significant clinical issue in the Asian community of British Columbia.     

Development of a Novel PmpD-N ELISA for Chlamydia psittaci Infection

ObjectiveChlamydia psittaci is an avian respiratory pathogen and zoonotic agent.The wide prevalence ofC. psittaci poses a threat to the poultry industry and its employees. However, few commercial kits are available for detecting avian antibodies excluding the in-house ELISA kit. In this study, we developed a novel ELISA kit for detecting antibodies againstC. psittaci based on the N-terminal fragment of polymorphic outer membrane protein D (PmpD-N) as the coating antigen.
Methods The antigen concentrations, primary antibody, and cut-off value were determined and optimized. The ELISA, designated PmpD-N ELISA, was assessed for sensitivity, specificity, and concordance using sera samples from 48 experimentally infected and 168 uninfected SPF chickens.
Results The sensitivity and specificity of PmpD-N ELISA were 97.9%, 100%, respectively, while the concordance was 98.1% as compared to that of MOMP-ELISA. No cross-reaction with positive sera for other avian pathogens was found. Using PmpD-N ELISA, 799/836 clinical samples were positive, including 93.0% and 98.1% positivity in layers and broilers, respectively.
Conclusion These data indicate that indirect ELISA with PmpD-N as the antigen candidate is a promising approach for the surveillance ofC. psittaci infection.     

Seroepidemiology of measles in immune generation in Taiwan: Prevalence of neutralizing antibody and immune response to reimmunization

BackgroundSecondary vaccine failure was the principal mechanic of measles reemergence in countries with high measles vaccine coverage. The information on neutralizing antibody (nAb) prevalence, epidemiological factors of waned immunity and immune response after reimmunization was essential to measles control but largely lacking in Taiwan.MethodsThe nAb and factors of wanned immunity to measles were evaluated in a cohort of 333 subjects aged 11–30 years in 2010. The longitudinal immune response to reimmunization (n = 30) and potential virus exposure (n = 24) were assessed in young healthcare workers (HCWs) during a hospital outbreak. The nAb titer was used to define susceptibility to measles disease (<120 mIU/mL) and infection (120–900 mIU/mL).ResultsIn the 2010 cohort, the susceptibility to measles diseases and infections was respectively identified in 35 (10.5%) and 226 (67.9%) subjects. A generalized linear model identified earlier ages of first immunization in childhood (P = 0.0214) and subjects aged ≥18 years (versus <18 years, P = 0.0425) as significant factors associated with lower nAb titers. Reimmunization of 30 seronegative HCWs resulted in seroconversion for all, with nAb titers significantly rising on day 5, peaking on day 15 and declining in month 4 post-immunization. Similar measles-specific IgG levels were observed in 24 seropositive HCWs before and 4 months after measles contact (P = 0.2352).ConclusionA lack of protective immunity to measles diseases might be identified in 10% of the Taiwanese population aged 11–30 years and associated with a trend toward earlier ages of the first measles vaccination. The wanned immunity can be boosted promptly by reimmunization but with uncertain durability.