Mycobacterium avium subspecies paratuberculosis seroconversion in dairy cattle and its association with raised somatic cell count

This retrospective case-control study investigates the relationship between seroconversion to Mycobacterium avium subspecies paratuberculosis (MAP) and raised somatic cell count (SCC). The study consists of 112 case cows from three dairy farms in the UK; for each case cow with a positive antibody titre, there was a seronegative control cow for comparison. Seroconversion was monitored using milk ELISA antibody titres for MAP taken at quarterly intervals. SCCs were recorded at the time a positive antibody titre was first recorded as well as at the previous and subsequent milk recording in order to explore a temporal relationship between the two events. The previous and subsequent milk recordings were a month before and after seroconversion was identified. The results showed that cows that were infected with MAP had an increased SCC around the time that they first became seropositive, providing evidence for a temporal relationship between the two events; high SCCs were particularly prevalent before and at the time of first detecting seroconversion. The explanation is being discussed that potentially an underlying, currently not studied, factor may be predisposing both events, the progression of paratuberculosis is predisposing the host to mastitis, or indeed intramammary infections help initiate paratuberculosis progression.

Estimation of the Seroconversion Duration of HIV-1 Antibodies in Individuals With Recent Infection in China

The identification of recent HIV-1 infection is clinically important for the effective treatment and prevention of transmission. However, the window period for seroconversion with respect to various HIV-1 antibodies is not well characterized. In addition, the routine HIV testing algorithms are not particularly appropriate for the identification of recent HIV-1 infection. In this study, we enrolled individuals who showed seroconversion from negative Western blot (WB) or indeterminate WB results and analyzed the window periods for appearance of HIV-1 antibodies. A total of 10,934 individuals with suspected HIV infection were tested by Wuhan CDC between 2012 and 2017; of these, 40 individuals with initial negative WB and 102 individuals with initial indeterminate WB who showed positive WB results within 100 days were included in the analysis. The mean time for seroconversion was 43.90 (95% confidence interval [CI]: 37.30-50.50) days and 42.15 (95% CI: 37.99-46.30) days, respectively. The time duration for p31 seroconversion among people with negative WB and indeterminate WB was 58.11 (95% CI, 44.30-71.92) days and 51.91 (95% CI, 44.55-59.28) days, respectively, both of which were significantly longer (p = 0.0169) than those in people without p31 seroconversion. A similar difference was observed with respect to p66 seroconversion, with a window time of 53.53 (95% CI, 43.54-63.52) days and 47.87 (95% CI, 43.16-52.57) days among people with negative WB and indeterminate WB, respectively. These data suggest that HIV-1 antibody p66, like p31, may serve as a potential serological marker for distinguishing Fiebig stage V and stage VI at day 70 post-infection.

Cutaneous plasmacytosis and multinucleate cell angiohistiocytoma-like lesion in a patient with hepatitis B: A fortuitous triad?

A 28-year-old woman of Chinese descent, with congenital chronic hepatitis B presented with a 7-year history of erythematous-brown papules and plaques on her groins, axillae, and forehead. A first skin biopsy showed findings consistent with two concomitant, yet highly uncommon cutaneous diseases. The presence of lymphoid nodules with germinal centers and clustered polyclonal plasma cells was consistent with cutaneous plasmocytosis. Second, a diffuse proliferation of non-atypical small vessels (CD31+, CD34+, and HHV8-) in a hypercellular stroma peppered with angulated giant cells (CD163+, CD68-) was suggestive of multinucleate cell angiohistiocytoma (MCAH). Interestingly, the second biopsy of a different plaque on the forehead showed only plasmacytosis and the clinical appearance of both plaques and papules alluded to the distinct presence of both concurrent entities. We speculate the immune modulating effects of chronic hepatitis B may have led to a polyclonal plasmacytic proliferation within the dermis. Furthermore, MCAH has been reported in conjunction with other inflammatory skin diseases such as hidradenitis suppurativa and as such we propose that the MCAH lesion in our case may have arisen as a secondary, reactive process to the cutaneous plasmacytosis.

Avian Influenza A Virus Infection among Workers at Live Poultry Markets, China, 2013-2016

We conducted a 3-year longitudinal serologic survey on an open cohort of poultry workers, swine workers, and general population controls to assess avian influenza A virus (AIV) seroprevalence and seroincidence and virologic diversity at live poultry markets (LPMs) in Wuxi City, Jiangsu Province, China. Of 964 poultry workers, 9 (0.93%) were seropositive for subtype H7N9 virus, 18 (1.87%) for H9N2, and 18 (1.87%) for H5N1. Of 468 poultry workers followed longitudinally, 2 (0.43%), 13 (2.78%), and 7 (1.5%) seroconverted, respectively; incidence was 1.27, 8.28, and 4.46/1,000 person-years for H7N9, H9N2, and H5N1 viruses, respectively. Longitudinal surveillance of AIVs at 9 LPMs revealed high co-circulation of H9, H7, and H5 subtypes. We detected AIVs in 726 (23.3%) of 3,121 samples and identified a high diversity (10 subtypes) of new genetic constellations and reassortant viruses. These data suggest that stronger surveillance for AIVs within LPMs and high-risk populations is imperative.

Acute Seroconversion of Eastern Equine Encephalitis Coinfection With California Serogroup Encephalitis Virus

Eastern equine encephalitis (EEE) is a severe arboviral neuroinvasive disease with high mortality and neurological sequelae. Treatment for EEE is primarily supportive. Intravenous immunoglobulin (IVIg) and high-dose steroids have been used as empirical therapy for EEE with some case reports of benefit. We report a case of a patient who presented with encephalopathy with initial cerebrospinal spinal fluid (CSF) serology analysis showing California serogroup encephalitis virus IgG positivity. However, the rapid clinical deterioration of the patient into a comatose state prompted a second CSF serology analysis that showed seroconversion of high titer Eastern Equine Encephalitis virus IgM and positive titer of California serogroup encephalitis virus IgG. The patient completed a 5-day course of empiric IVIg without concurrent corticosteroid therapy but did not show significant clinical improvement.

Complex decisions: correlates of injectable contraceptive discontinuation following HIV-1 seroconversion in an HIV prevention trial

Contraceptive adherence during acute and recent HIV-1 infection is important to maternal and child health given the elevated risk of vertical HIV-1 transmission and additional complications of pregnancy. Injectable contraception (IC) is the most common non-barrier modern contraception method used in sub-Saharan Africa (SSA). Adherence to IC after HIV-1 seroconversion is not well understood. We examined factors associated with IC discontinuation among women in SSA diagnosed with HIV-1 infection while participating in a clinical trial of biomedical HIV-1 prevention. After diagnosis with HIV-1 infection in the VOICE trial, 255 women from South Africa, Uganda, and Zimbabwe enrolled in a longitudinal observational study (MTN-015). Contraceptive method was assessed at MTN-015 baseline and at 3, 12, and 24 months post-seroconversion. Correlates of IC discontinuation were examined by Cox proportional hazard modeling. IC use was reported at baseline by 78% of women enrolled (198/255), of which 92% (182/198) completed at least one follow-up visit. Two-thirds of women (66%, 121/182) continued on IC during the follow-up period (median 24 months). Lower rates of IC discontinuation were observed in women who reported having had at least one child (HR 0.39, 95% CI 0.20-0.82) or earning a personal income (HR 0.51, 95% CI 0.30-0.87) at baseline. These findings suggest that many women with HIV-1 infection face complex decision-making regarding family planning in the years that follow seroconversion and highlight that some women may discontinue IC use despite on-site provision of family planning services. Understanding the broader context of family planning choices in recently seroconverted women may be key to more effective linkages between family planning services and HIV-1 testing and care.

Changing paradigm in the epidemiology of Japanese encephalitis in a non-endemic region

Background & objectives

Japanese encephalitis (JE) is a mosquito-borne zoonotic disease. The JE virus (JEV) does not cause any disease among its natural hosts and transmission continues through mosquitoes belonging to Culex vishnui subgroup. This study was aimed to investigate the prevalence of JEV in mosquitoes and humans in the Thanjavur district, a non-endemic region for JE, in Tamil Nadu, by using standard available assays.

Methods

: A sero-surveillance study was conducted in Thanjavur district among the normal rural school children in the 5-12 yr age group, during the JE season (October) and post-JE season (February) from 2011 to 2013 for the detection of JEV infection. Vector abundance studies were carried out from 2011 to 2014. JE seropositivity and its association between the seasons were analysed statistically.

Results

: The occurrence of JE infection among children aged 5-12 yr was very high in the study area. The infection rates for JE in two consecutive seasons for 2011-12 and 2012-13 were 32.2 and 65.2%, respectively. The Cx. tritaeniorhynchus sp. dominated the catch, and was majorly responsible for the transmission. There was a significant difference in the human infection rate compared to the years 1991-92 and 1992-93; and a marked decrease in the cattle to pigs ratio (123 : 1) compared to the studies in 1991-93.

Interpretation & conclusion

: The study unearthed the prevailing situation of JE among children, who are at higher risk of developing the disease during the transmission season. The decrease in the cattle to pigs ratio might be the one of the reasons for increase in the JEV infection among the children population compared to 20 years before. This trend requires urgent attention as it could be prevented with effective surveillance systems and vaccines.

Immunogenicity of different dosing schedules of the human live attenuate rotavirus vaccine (RV1) in infants and children: a meta-analysis

Rotavirus immunization strategies have become part of a comprehensive global public health program to control rotavirus-associated gastroenteritis, particularly in infants and children in developing countries. Several studies have reported the efficacy of different rotavirus vaccine dosing schedules, but with mixed findings. Therefore a systematic review of the published literature on rotavirus vaccination dosing schedules using the live attenuated RV1 rotavirus vaccine in infants and children, including randomized controlled clinical trials (RCTs), published between January 1998 to January 2018 was conducted, with meta-analysis of the published data. The literature search was performed using six databases. The initial review identified 495 publications, of which three satisfied the selection eligibility criteria. The three studies that assessed RV1 rotavirus vaccine immunogenicity compared a two-dose vaccination schedule with a three-dose vaccination schedule. The use of a three-dose vaccination schedule did not show a statistically significant seroconversion rate when compared with a two-dose vaccination schedule (OR = 0.87; 95% CI,: 0.65--1.17;, p- = 0.298). Analysis of included studies with one-month follow-up time showed that the three-dose vaccination schedule did not result in have significantly increased geometric mean concentrations (GMCs) compared with the two-dose vaccination schedule (p = 0.311).Rotavirus immunogenicity did not increase significantly with the three-dose schedule at 6, 10 and 14 weeks with the two-dose schedule at 10 and 14 weeks. These findings indicate that further controlled studies should be undertaken to support the optimum immunization schedules for rotavirus in terms of clinical effectiveness and cost-effectiveness, particularly for infants and children in developing countries.

Early Treatment of Primary HIV Infection Is Associated with Decreased Mortality

The aim of this study was to understand factors associated with increased mortality in a cohort of primary HIV infection (PHI) in New South Wales (NSW) over three decades. Six hundred and two patients with PHI were enrolled from 1984 to 2009. Probabilistic data linkage was performed to NSW Registry of births deaths and marriages and Australian Bureau of Statistics mortality database. Mortality was measured by crude death rate. Pre highly active antiretroviral therapy (pre-HAART) era was defined as before January 1, 1997. A Cox proportional hazard model was used to identify factors associated with death. One hundred and thirty-eight deaths occurred during 6,223 person years (PY) follow-up. Overall crude death rate was 2.2 per 100 PY (95% confidence interval [CI], 1.9-2.6), 3.6 (95% CI, 3.1-4.3)in pre-HAART era and 0.20 (95% CI, 0.08-0.47) in post-HAART era. AIDS was the most frequent cause of death (52%, 72/138), all occurring in the pre-HAART era. Of non-AIDS deaths, the leading known cause was non-AIDS cancer 8% (11/138) followed by suicide 4% (6/138). On multivariate analysis, estimated date of infection in pre-HAART era and time to commencement of ART greater than 1 year post diagnosis were more likely to be associated with death (p < .05). Mortality in PHI has decreased significantly in the post-HAART era. Non-AIDS deaths due to malignancy and suicide are emerging as leading causes in this population in the post-HAART era. Time to starting ART greater than 1 year was associated with increased mortality.

Impact of Disease-Modifying Treatments on the Longitudinal Evolution of Anti-JCV Antibody Index in Multiple Sclerosis

Background: Risk of natalizumab-related progressive multifocal leukoencephalopathy is associated with the presence of anti-JC-virus (JCV) antibodies.

Objective: To investigate the impact of disease-modifying treatments (DMT) on the longitudinal evolution of anti-JCV antibody index.

Methods: Patients with multiple sclerosis who had serum sampling at intervals of 6 ± 3 months over up to 6 years and who either started DMT (interferon-β, glatiramer acetate or natalizumab) during the observation period with at least one serum sample available before and after treatment initiation or received no DMT during the observation period were included. Anti-JCV antibody serological status and index were determined by 2-step second-generation anti-JCV antibody assay.

Results: A total of 89 patients were followed for a median time of 55.2 months. Of those, 62 (69.7%) started DMT and 27 (30.3%) were without therapy during the observation period. Variation of longitudinal anti-JCV antibody index ranged from 9 to 15% and was similar in patients with and without DMT. Applying a mixed model considering the combined effects of treatment and time as well as individual heterogeneity did not show a significant change of anti-JCV antibody index by the start of treatment with interferon-β, glatiramer acetate, or natalizumab.

Conclusion: Evaluated DMTs do not impact longitudinal anti-JCV antibody index evolution.

Systematic review and meta-analysis: Development of hepatocellular carcinoma in chronic hepatitis B patients with hepatitis e antigen seroconversion

Hepatitis B e antigen (HBeAg) seroconversion is considered to have significantly favourable clinical outcomes for patients with chronic hepatitis B (CHB). However, inconsistent study results suggest that hepatocellular carcinoma (HCC) still occurs in patients with HBeAg seroconversion. We performed a systematic review and meta-analysis to determine the incidence of HCC in patients with CHB after HBeAg seroconversion. Web of Science, PubMed and Embase databases were searched through January 2017. The incidence of HCC in CHB patients after HBeAg seroconversion was pooled using a random-effects model or fix-effects model. Sixteen studies were finally included, involving 4910 patients with HBeAg seroconversion. The overall pooled proportion suggested that 3.33% (95% confidence interval (CI): 2.28%-4.58%) of patients with CHB develop HCC despite HBeAg seroconversion. In patients with HBeAg seroconversion without cirrhosis, the pooled proportion of HCC development was 0.94% (95% CI: 0.15%-2.4%). Moreover, patients with cirrhosis, active hepatitis, or aged greater than 40 years at the time of HBeAg seroconversion were at significantly higher risk for HCC development. HBeAg seroconversion was significantly associated with a reduced risk of HCC compared with persistently positive HBeAg (RR = 0.58, 95% CI: 0.35-0.97, P = .04). Despite the reduced risk with HBeAg seroconversion, HCC can still occur in a proportion of patients with CHB after HBeAg seroconversion. Long-term monitoring is needed for patients with established cirrhosis, active hepatitis or those older than 40 years at the time of HBeAg seroconversion.

Repeated False-Positive HIV Test Results in a Patient Taking HIV Pre-Exposure Prophylaxis

Regular HIV testing is required to ensure the safety of HIV pre-exposure prophylaxis (PrEP). We describe and discuss a series of false-positive HIV test results from an individual receiving PrEP. The expansion of PrEP will likely result in greater numbers of false-positive test results that may pose challenges for interpretation.

Seroconversion for Cytomegalovirus Infection During Pregnancy and Fetal Infection in a Highly Seropositive Population: "The BraCHS Study"

We determined the risk of seroconversion in seronegative pregnant women living in a high seroprevalence population. Cytomegalovirus (CMV)-immunoglobulin G reactivity was determined at the 1st trimester in all women and sequentially for seronegative women. A total of 1915 of 1952 (98.1%; 95% confidence interval [CI], 97.4%-98.7%) women were seropositive, and 36 (1.8%; 95% CI, 1.3%-2.6%) were seronegative. Five of the 36-seronegative women seroconverted for a cumulative rate of 13.9% (95% CI, 4.8%-30.6%). Congenital CMV infection was diagnosed in 1 of 36 infants (2.8%; 95% CI, 0.5%-63.9%) born to seronegative women compared with 8 of 1685 (0.5%; 95% CI, 0.2%-1.0%) infants born to seropositive mothers. Even with a high risk of primary infection in seronegative women, most CMV-infected infants were born to women with pre-existing seroimmunity.

An adjuvant compound that enhances immunogenicity at fractional doses of the Sabin-inactivated poliovirus vaccine (sIPV) with a long duration of protection in a rat model

BACKGROUND

At the same dosage, the new generation of Sabin-inactivated poliovirus vaccine (sIPV) is less immunogenic than the traditional oral polio vaccine (OPV) dosage in China. The useful adjuvant might be a necessary strategy to strengthen the immune protective effects.

METHODS

In this study, we produced an adjuvant compound (named KML05) that could promote immunogenicity and fractional doses of sIPV with a long duration of protection in a rat model. The compound adjuvant had both advantages and a function of MF59 and carbopol971P.

RESULTS

The effect seroconversion of experimental animals immunized with KML05 could be extended to one-eighth of the dose. According to the result of the geometric mean titers (GMTs), KML05 adjuvant could save eight times the amount of sIPV D-antigen usage, but aluminum hydroxide adjuvant could save twice at the same titers. Additionally, it was found that there was a significant difference in the GMT titer of poliovirus type 2 between animals immunized by KML05 and alum adjuvant (P < 0.05). At 12th-month postvaccination, the neutralization titers stimulated by IPV-KML05 were maintained over a longer time period in immunized animals.

CONCLUSION

Our research team developed KML05 adjuvant, which combined carbopol971P with MF59, increased antibody responses to sIPV for a longer duration of protection in a rat model.

HIV infection after prenatal screening: an open window leading to perinatal infection

Despite a dramatic decrease in vertical transmission of HIV in the developed world, maternal HIV infection acquired after negative prenatal screening still leaves a window of vulnerability. Through quality assurance programs in two Canadian Provinces, five cases where perinatal HIV transmission occurred despite negative prenatal screening were identified between 2005 and 2015. Maternal risk factors such as intravenous drug use, high-risk sexual behavior, hepatitis C virus co-infection, and belonging to high prevalence minority groups were common. Two mothers had their negative HIV test performed in the first trimester and three mothers had negative testing in the third trimester. All babies were clinically healthy at delivery with a normal weight. Three babies were tested following subsequent identification of maternal HIV infection and two babies presented with opportunistic infections leading to their diagnoses. The characteristics of these cases suggest that to achieve complete elimination of vertical HIV transmission, selective and innovative clinical management of mothers at high risk for HIV may be required.

A Strategy for PrEP Clinicians to Manage Ambiguous HIV Test Results During Follow-up Visits

Prompt determination of HIV infection status is critical during follow-up visits for patients taking pre-exposure prophylaxis (PrEP) medication. Those who are uninfected can then continue safely taking PrEP, and those few who have acquired HIV infection can initiate an effective treatment regimen. However, a few recent cases have been reported of ambiguous HIV test results using common testing algorithms in PrEP patients. We review published reports of such cases and testing options that can be used to clarify true HIV status in these situations. In addition, we review the benefits and risks of 3 antiretroviral management options in these patients: (1) continue PrEP while conducting additional HIV tests, (2) initiate antiretroviral therapy for presumptive HIV infection while conducting confirmatory tests, or (3) discontinue PrEP to reassess HIV status after a brief antiretroviral-free interval. A clinical consultation resource is also provided.

Seroconversion after needlestick injuries - analyses of statutory accident insurance claims in Germany

Objective: After a needlestick injury (NSI) with contaminated blood, there is a risk of seroconversion. Statutory accident insurance (SAI) claims data were used to determine the numbers of seroconversions for hepatitis B and C viruses (HBV, HCV) and for HIV.

Materials and methods: Cases of HBV, HCV or HIV infection recognised as occupational diseases between 2006 and 2015 were selected from the BGW (Berufsgenossenschaft für Gesundheitsdienst und Wohlfahrtspflege) database. Cases where an NSI was reported to the accident insurer before the diagnosis of the infectious disease was made were included in the analysis. The causal link between the infection and the NSI identified was estimated based on diagnostic findings in medical case files.

Results: In total, 566 cases with an occupation-related HBV, HCV or HIV infection were identified, including 44 cases where an NSI had been reported before diagnosis. Data on file indicated a possible causal link in 34 cases. In 16 of the 34 cases, seroconversion after the NSI was proven by diagnostic findings; in 13 of the 34 cases, seroconversion was possible but not proven because of the lack of initial findings. The index case was known in 23 of the 34 cases. The injuries occurred most often during waste disposal and high-risk procedures such as taking blood samples. The injuries were most often caused by cannulas for intravenous puncture. Subcutaneous devices were involved in two NSIs but there was no information on the initial serology or known index case.

Conclusions: It is possible to identify seroconversion in SAI claims data. However, data on the injured person’s initial infection status is often incomplete and this makes it difficult to assess any causal link. The incidence of seroconversions resulting from injuries from subcutaneously applied devices is apparently low; this is consistent with the literature.

Molecular characterization of hepatitis B virus (HBV) in African children living in Australia identifies genotypes and variants associated with poor clinical outcome

Migration from sub-Saharan Africa is contributing to the rising incidence of chronic hepatitis B (CHB) infection and its complications in Australia. African CHB is associated with unique genotypes, such as E and A1, which are associated with reduced vaccine efficacy and early-onset hepatocellular carcinoma, respectively, although the prevalence of these genotypes outside Africa is poorly described. Treatment-naïve children of African origin with CHB were recruited at the Royal Children's Hospital Melbourne. Population-based sequencing of the complete HBV genome, or the clinically relevant basal core promoter (BCP)/precore (PC) region, was performed, and the HBV genotype/subgenotype assigned by phylogenetic analysis. HBV was characterized in serum from 67 children, median age 12.5 years. HBV genotype E was most frequent (70 %), with genotype D [25 %; subgenotypes D6 (formerly D7)/D3/D2)] and subgenotype A1 (5 %) also being identified. Despite their young age, over 50 % of the children were HBeAg-negative and had seroconverted to anti-HBe, with this being associated with canonical BCP/PC mutations in the majority of cases. The profile of HBV in African children living in Australia was characterized by early HBeAg seroconversion and infection with HBV variants associated with poor clinical outcome, as well as genotypes previously associated with reduced vaccine efficacy or rapid progression to liver cancer. These findings have important ramifications for patient monitoring and treatment guidelines in the Australian paediatric setting.

Metabolic characterization of plasma samples in HIV-1-infected individuals

AIM

To identify potential biomarkers for the diagnosis and monitoring of HIV-1 progression.

METHODS

19 subjects, diagnosed with HIV-1 infection in the follow-up, prospective, clinical cohort more than 6000 subjects from 2006, were incorporated into our study. The subjects included ten non-progressors and nine rapid progressors. The plasmas of subjects before HIV-1 seroconversion and after seroconversion were collected and analyzed with nontargeted metabolomics.

RESULTS

20:0-Glc-Campesterol and A-norgorgostanol could significantly distinguished after HIV-1 seroconversion from before HIV-1 seroconversion. PG(O-18:0/18:0) could totally distinguish the plasma of rapid progressor before seroconversion from that of nonprogressor before seroconversion.

CONCLUSION

20:0-Glc-Campesterol, A-norgorgostanol and  PG(O-18:0/18:0) could be potential biomarkers for the diagnosis and monitoring of HIV-1 progression.

Decline of maternal antibodies to small ruminant lentivirus in goat kids

We carried out this study to determine for how long small ruminant lentivirus (SRLV)-specific antibodies can be detected by three commercial ELISA kits in goat kids after suckling infected does in field conditions. Forty-one kids born to SRLV-seropositive asymptomatic does were blood sampled prior to colostrum consumption, and then weekly for 6 months in total. The sera were screened with three commercial ELISA kits: whole-virus ELISA (wELISA), recombinant transmembrane and capsid antigen ELISA (TM/CA-ELISA), and surface antigen ELISA (SU-ELISA). All but one kid were seronegative in all three ELISAs right after birth. At the age of 1 week all kids turned seropositive in wELISA, 39 kids (95%) in TM/CA-ELISA, and 35 kids (85%) in SU-ELISA. All seropositive kids turned seronegative in wELISA by the 15th week, and in SU-ELISA by the 19th week (median of 8 weeks in both ELISA), whereas in TM/CA-ELISA five kids (13% of 39 initially seropositive) were still seropositive at the age of 6 months (median of 11 weeks). Antibody levels at the age of 1 week proved significantly linked to the duration of maternal antibodies in all three ELISAs and could be employed to predict for how long maternal antibodies would remain detectable.

Exocrine pancreas function decreases during the progression of the beta-cell damaging process in young prediabetic children

OBJECTIVE

The function of the exocrine pancreas is decreased in patients with type 1 diabetes but it is not known when this defect develops. The current study set out to determine whether the reduced exocrine function becomes manifest after the initiation of islet autoimmunity.

METHODS

The study was nested in the prospective Type 1 Diabetes Prediction and Prevention study where children with human leukocyte antigen (HLA)-conferred susceptibility are observed from birth. Elastase-1 levels were analyzed from stool samples collected at the time of seroconversion to islet autoantibody positivity and at diagnosis of type 1 diabetes, as well as from samples taken from matched control children of similar age.

RESULTS

Elastase levels were lower in case children at the time of the diagnosis of diabetes when compared to the control children. However, elastase concentrations did not differ between cases and controls at the time when autoantibodies appeared.

CONCLUSION

The results suggest that the defect in the exocrine function develops after the appearance of islet autoantibodies. Further studies are needed to assess whether reduced elastase levels predict rapid progression of islet autoimmunity to clinical disease.

Serum hepatitis B core antibody levels predict HBeAg seroconversion in chronic hepatitis B patients with high viral load treated with nucleos(t)ide analogs

Background

Patients with chronic hepatitis B virus (HBV) infection who are hepatitis B virus e antigen (HBeAg) positive are increasingly being treated with nucleos(t)ide analogs (NUCs). However, the predictive value of serum hepatitis B virus core antibody (HBcAb) levels for HBeAg seroconversion among patients with high viral load remains unclear.

Methods

This study consisted of 74 patients with high viral load (HBV DNA >1 × 10⁷ copies/mL) enrolled in a multicenter, randomized, controlled trial, treated with lamivudine and adefovir (N = 32) or entecavir (N = 42) for up to 96 weeks. Serum HBV DNA, quantitative hepatitis B virus surface antigen (HBsAg), HBeAg, and HBeAb was tested at each visit. Quantitative HBcAb evaluation was conducted for all the available samples in the trial, by using a newly developed double-sandwich anti-HBc immunoassay.

Results

Serum HBcAb levels were significantly higher in patients with a serum alanine aminotransferase (ALT) level more than five times the upper limit of normal (ULN) compared with patients with ALT levels within 5 × ULN (4.25 ± 0.61 vs. 3.94 ± 0.47 log₁₀ IU/mL, P = 0.0345). Patients with HBeAg seroconversion were associated with a higher level of HBcAb at baseline, compared with those without HBeAg seroconversion (4.38 ± 0.54 vs. 4.02 ± 0.58 log₁₀ IU/mL, P = 0.029). The area under receiver operating characteristic curve of baseline HBcAb for HBeAg seroconversion was 0.71 (95% CI: 0.55-0.86, P = 0.013). When the baseline HBcAb level was >4.375 log₁₀ IU/mL, the sensitivity and specificity to predict HBeAg seroconversion at week 96 were 62.5% and 74.2%, and the positive likelihood ratio (LR) and negative LR were 2.42 and 0.51, respectively. The multivariate analysis result indicated that baseline serum HBcAb level was the only independent predictor for HBeAg seroconversion at week 96, with an odds ratio of 4.78.

Conclusion

Baseline serum HBcAb level >4.375 log₁₀ IU/mL could satisfactorily predict HBeAg seroconversion among patients with high viral load treated with NUC.

When is Helicobacter pylori acquired in populations in developing countries? A birth-cohort study in Bangladeshi children

Helicobacter pylori colonization is prevalent throughout the world, and is predominantly acquired during childhood. In developing countries, >70% of adult populations are colonized with H. pylori and >50% of children become colonized before the age of 10 years. However, the exact timing of acquisition is unknown. We assessed detection of H. pylori acquisition among a birth cohort of 105 children in Mirzapur, Bangladesh. Blood samples collected at time 0 (cord blood), and at 6, 12, 18, and 24 months of life were examined for the presence of IgG and IgA antibodies to whole cell H. pylori antigen and for IgG antibodies to the CagA antigen using specific ELISAs and immunoblotting. Breast milk samples were analyzed for H. pylori-specific IgA antibodies. Cord blood was used to establish maternal colonization status. H. pylori seroprevalence in the mothers was 92.8%. At the end of the two-year follow-up period, 50 (47.6%) of the 105 children were positive for H. pylori in more than one assay. Among the colonized children, CagA prevalence was 78.0%. A total of 58 children seroconverted: 50 children showed persistent colonization and 8 (7.6%) children showed transient seroconversion, but immunoblot analysis suggested that the transient seroconversion observed by ELISA may represent falsely positive results. Acquisition of H. pylori was not influenced by the mother H. pylori status in serum or breastmilk. In this population with high H. pylori prevalence, we confirmed that H. pylori in developing countries is detectable mainly after the first year of life.

West Nile Virus Seroprevalence, Connecticut, USA, 2000-2014

West Nile virus (WNV) infection is mainly asymptomatic but can be severe in elderly persons. As part of studies on immunity and aging in Connecticut, USA, we detected WNV seroconversion in 8.5% of nonimmunosuppressed and 16.8% of immunosuppressed persons. Age was not a significant seroconversion factor. Our findings suggest that immune factors affect seroconversion.

HIV-1 Subtypes and 5'LTR-Leader Sequence Variants Correlate with Seroconversion Status in Pumwani Sex Worker Cohort

Within the Pumwani sex worker cohort, a subgroup remains seronegative, despite frequent exposure to HIV-1; some of them seroconverted several years later. This study attempts to identify viral variations in 5′LTR-leader sequences (5′LTR-LS) that might contribute to the late seroconversion. The 5′LTR-LS contains sites essential for replication and genome packaging, viz, primer binding site (PBS), major splice donor (SD), and major packaging signal (PS). The 5′LTR-LS of 20 late seroconverters (LSC) and 122 early seroconverters (EC) were amplified, cloned, and sequenced. HelixTree 6.4.3 was employed to classify HIV subtypes and sequence variants based on seroconversion status. We find that HIV-1 subtypes A1.UG and D.UG were overrepresented in the viruses infecting the LSC (P < 0.0001). Specific variants of PBS (Pc < 0.0001), SD1 (Pc < 0.0001), and PS (Pc < 0.0001) were present only in the viral population from EC or LSC. Combinations of PBS [PBS-2 (Pc < 0.0001) and PBS-3 (Pc < 0.0001)] variants with specific SD sequences were only seen in LSC or EC. Combinations of A1.KE or D with specific PBS and SD variants were only present in LSC or EC (Pc < 0.0001). Furthermore, PBS variants only present in LSC co-clustered with PBS references utilizing tRNA^Arg; whereas, the PBS variants identified only in EC co-clustered with PBS references using tRNA^Lys,3 and its variants. This is the first report that specific PBS, SD1, and PS sequence variants within 5′LTR-LS are associated with HIV-1 seroconversion, and it could aid designing effective anti-HIV strategies.

Detection of HEV-specific antibodies in four non-human primate species, including great apes, from different zoos in Germany

The hepatitis E virus (HEV) has been described in humans and various animal species in different regions of the world. However, the knowledge on natural HEV infection in non-human primates and the corresponding risk of zoonotic transmission is scarce. To determine whether primates in captivity are affected by HEV infection, we investigated 259 individual sera of clinically healthy non-human primates of 14 species from nine German zoos. Using a commercial double-antigen-sandwich ELISA and a commercial IgG ELISA, 10 animals (3·9%) reacted positive in at least one assay. Three ape species and one Old World monkey species were among the seropositive animals: bonobo (Pan paniscus), gorilla (Gorilla gorilla gorilla), lar gibbon (Hylobates lar) and drill (Mandrillus leucophaeus). Testing for anti-HEV-IgM antibodies by commercial ELISA and for viral RNA by reverse-transcription real-time polymerase chain reaction resulted in negative results for all animals indicating the absence of acute HEV infections. In the past, no clinical signs of hepatitis were recorded for the seropositive animals. The results suggest that non-human primates in zoos can get naturally and subclinically infected with HEV or related hepeviruses. Future studies should evaluate potential sources and transmission routes of these infections and their impact on human health.

Longitudinal study of surrogate aging measures during human immunodeficiency virus seroconversion

Persons living with human immunodeficiency virus (HIV) harbor an increased risk of age-related conditions. We measured changes in telomere length and DNA methylation in the peripheral blood of 31 intravenous drug users, who were followed longitudinally with blood samples pre-HIV (T1), immediately post-HIV (T2; 1.9±1 year from T1), and at a later follow-up time (T3; 2.2±1 year from T2). Absolute telomere length measurements were performed using polymerase chain reaction methods. Methylation profiles were obtained using the Illumina Human Methylation450 platform. Methylation aging was assessed using the Horvath method. Telomere length significantly decreased between T1 and T2 (227±46 at T1 vs. 201±48 kbp/genome at T2, p=0.045), while no differences were observed between T2 and T3 (201±48 at T2 vs. 186±27 kbp/genome at T3, p=0.244). Methylation aging as measured by the age acceleration residual increased over the time course of HIV infection (p=0.035). CpG sites corresponding to PCBP2 and CSRNP1 were differentially methylated between T1 and T2 at a q-value <0.05. Telomere shortening and methylation changes can therefore be observed in the short-term period immediately following HIV seroconversion. Further studies to confirm these results in larger sample sizes and to compare these results to non-HIV and non-injection drug users are warranted.

Effect of Probiotics and Prebiotics on Immune Response to Influenza Vaccination in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

We conducted a meta-analysis to evaluate the effects of probiotics and prebiotics on the immune response to influenza vaccination in adults. We conducted a literature search of Pubmed, Embase, the Cochrane Library, the Cumulative Index to Nursing and Allied Health (CINAHL), Airiti Library, and PerioPath Index to Taiwan Periodical Literature in Taiwan. Databases were searched from inception to July 2017. We used the Cochrane Review risk of bias assessment tool to assess randomized controlled trial (RCT) quality. A total of 20 RCTs comprising 1979 adults were included in our systematic review. Nine RCTs including 623 participants had sufficient data to be pooled in a meta-analysis. Participants who took probiotics or prebiotics showed significant improvements in the H1N1 strain seroprotection rate (with an odds ratio (OR) of 1.83 and a 95% confidence interval (CI) of 1.19–2.82, p = 0.006, I² = 0%), the H3N2 strain seroprotection rate (OR = 2.85, 95% CI = 1.59–5.10, p < 0.001, I² = 0%), and the B strain seroconversion rate (OR = 2.11, 95% CI = 1.38–3.21, p < 0.001, I² = 0%). This meta-analysis suggested that probiotics and prebiotics are effective in elevating immunogenicity by influencing seroconversion and seroprotection rates in adults inoculated with influenza vaccines.

A review of immunogenicity and tolerability of live attenuated Hepatitis A vaccine in children

Changing epidemiology of Hepatitis A virus (HAV) has led to an increased susceptibility of adolescents and adults to the infection. Vaccination can remarkably reduce the incidence and associated morbidity of HAV infection. This review is focused on the safety and efficacy of H2 strain derived live attenuated Hepatitis A vaccine. We found the vaccine to be highly immunogenic with minimal or negligible safety issues. Moreover, a single dose of live attenuated vaccine persists a long term immune response and can be a preferred option for developing countries. In 2014, Indian Academy of Paediatrics (IAP) also updated their recommendations for H2 vaccine as a single dose as against the previous 2 dose schedule. A focused approach to include the vaccine in national immunization program should be explored.

Experimental Infection of Young Pigs with an Early European Strain of Porcine Epidemic Diarrhoea Virus and a Recent US Strain

Outbreaks of porcine epidemic diarrhoea (PED) were reported across Europe during the 1980s and 1990s, but only sporadic outbreaks occurred in recent years. PED virus (PEDV) spread for the first time into the USA in 2013 and has caused severe economic losses. Retrospectively, it was found that two different strains of PEDV have been introduced into the United States, both are closely related to strains circulating in China where a new wave of the disease occurred from 2010 onwards. Since autumn 2014, new outbreaks of PED have occurred in Europe. In this study, weaned piglets were inoculated with an early European isolate (Br1/87) or faecal/intestinal suspensions derived from pigs infected with a recent European strain of PEDV (from Germany) or a US strain of PEDV. No evidence for infection resulted from inoculation of pigs with the German sample that contained high levels of PEDV RNA; there were no clinical signs, excretion of viral RNA or anti-PEDV antibody production. In contrast, all the pigs in the other two groups showed evidence of infection. Mild clinical signs of disease, mainly diarrhoea, occurred in piglets inoculated with the Br1/87 and US PEDV strains. PEDV RNA was detected throughout the intestine in euthanized animals at 4 days post-inoculation. In addition, within these animals, low levels of viral RNA were detected in lungs and livers with higher levels in spleens. Seroconversion against PEDV occurred in all surviving infected animals within 10 days. PEDV RNA excretion occurred for at least 2 weeks. The US PEDV RNA was detected at low levels in serum samples on multiple days. It is apparent that current diagnostic systems can detect infection by the different virus strains.

Rotavirus vaccine response correlates with the infant gut microbiota composition in Pakistan

Rotavirus (RV) is the leading cause of diarrhea-related death in children worldwide and ninety-five percent of rotavirus deaths occur in Africa and Asia. Rotavirus vaccines (RVV) can dramatically reduce RV deaths, but have low efficacy in low-income settings where they are most needed. The intestinal microbiome may contribute to this decreased RVV efficacy. This pilot study hypothesizes that infants' intestinal microbiota composition correlates with RVV immune responses and that RVV responders have different gut microbiota as compared to non-responders. We conducted a nested, matched case-control study comparing the pre-vaccination intestinal microbiota composition between 10 6-week old Pakistani RVV-responders, 10 6-week old Pakistani RVV non-responders, and 10 healthy Dutch infants.  RVV response was defined as an Immunoglobulin A of ≥20 IU/mL following Rotarix™(RV1) vaccination in an infant with a pre-vaccination IgA<20. Infants were matched in a 1:1 ratio using ranked variables: RV1 dosing schedule (6/10/14; 6/10; or 10/14 weeks), RV season, delivery mode, delivery place, breastfeeding practices, age and gender. Fecal microbiota analysis was performed using a highly reproducible phylogenetic microarray. RV1 response correlated with a higher relative abundance of bacteria belonging to Clostridium cluster XI and Proteobacteria, including bacteria related to Serratia and Escherichia coli. Remarkably, abundance of these Proteobacteria was also significantly higher in Dutch infants when compared to RV1-non-responders in Pakistan. This small but carefully matched study showed the intestinal microbiota composition to correlate with RV1 seroconversion in Pakistan infants, identifying signatures shared with healthy Dutch infants.

Primary seroresponses to double-dose compared with standard-dose hepatitis B vaccination in patients with chronic kidney disease: a systematic review and meta-analysis

Background

Clinical guidelines recommend double-dose hepatitis B vaccination for patients requiring dialysis, due to an increased risk of hepatitis B infection and reduced vaccine responsiveness. There are no recommendations for patients with chronic kidney disease (CKD) prior to dialysis.

Methods

We performed a systematic review and meta-analysis of randomized and quasi-randomized trials comparing efficacy (seroresponses) and harms of double-dose compared with standard-dose hepatitis B vaccination in patients with CKD, including those requiring dialysis. A systematic literature search (CENTRAL, MEDLINE and EMBASE) was performed using a predetermined search strategy. Relative risks were calculated from pooled data using a random-effects model with subgroup analysis by dialysis requirement and vaccine type.

Results

Seven studies (501 patients) fulfilled review criteria: four in patients receiving dialysis and three in patients not receiving dialysis. The incidence of seroconversion was not increased with double-dose vaccination overall [risk ratio (RR) 1.17, 95% confidence interval (CI) 0.98-1.39], by dialysis requirement or vaccine type. The incidence of seroprotection (reported by only four studies) was increased with double-dose vaccination overall (RR 1.53, 95% CI 1.17-2.00) but not by dialysis requirement. Adverse events were not reported by treatment arm, precluding comparison. The overall quality of included studies was moderate to low.

Conclusions

The current data do not support clinical guideline recommendations for administering double-dose vaccination for patients with CKD as seroconversion was not improved and seroprotection was inadequately assessed. Large high-quality studies are required to overcome the current evidence gap regarding vaccine dosing in CKD.

HIV seroconversion among Baltimore City residents tested at a mobile van programme

BACKGROUND

Many individuals with HIV in the USA are unaware of their diagnosis, and therefore cannot be engaged in treatment services, have worse clinical outcomes and are more likely to transmit HIV to others. Mobile van testing may increase HIV testing and diagnosis. Our objective was to characterise risk factors for HIV seroconversion among individuals using mobile van testing.

METHODS

A case cohort study (n=543) was conducted within an HIV surveillance dataset of mobile van testing users with at least two HIV tests between September 2004 and August 2009 in Baltimore, Maryland. A subcohort (n=423) was randomly selected; all additional cases were added from the parent cohort. Cases (n=122 total, two from random subcohort) had documented seroconversion at the follow-up visit. A unique aspect of the analysis was use of Department of Corrections data to document incarceration between the times of initial and subsequent testing. Multivariate Cox proportional hazards models were used to compare HIV transmission risk factors between individuals who seroconverted and those who did not.

RESULTS

One hundred and twenty-two HIV seroconversions occurred among 8756 individuals (1.4%), a rate higher than that in Baltimore City Health Department's STD Clinic clients (1%). Increased HIV seroconversion risk was associated with men who have sex with men (MSM) (HR 32.76, 95% CI 5.62 to 191.12), sex with an HIV positive partner (HR 70.2, 95% CI 9.58 to 514.89), and intravenous drug use (IDU) (HR 5.65, 95% CI 2.41 to 13.23).

CONCLUSIONS

HIV testing is a crucial first step in the HIV care continuum and an important HIV prevention tool. This study confirmed the need to reach high-risk populations (MSM, sex with HIV-positive individuals, individuals with IDU) and to increase comprehensive prevention services so that high-risk individuals stay HIV uninfected. HIV testing in mobile vans may be an effective outreach strategy for identifying infection in certain populations at high risk for HIV.

Safety and effectiveness assessment of 2011-2012 seasonal influenza vaccine produced in China: a randomized trial

OBJECTIVE

This study evaluated the effectiveness and safety of the egg-based, trivalent, inactivated split influenza vaccine produced by the Institute of Medical Biology, Chinese Academy of Medical Sciences, Peking Union Medical College, China.

METHODS

From March 2012 through May 2012, we enrolled a total of 1390 healthy volunteers between the ages of 3 and 80 years in a randomized clinical trial at the Hebei Disease Control Center Vaccine Clinical Evaluation Center. For all subjects, body part adverse reactions and whole-body adverse reactions were observed 30 min, 6 h, and 1-7 days' post-inoculation. If no severe adverse effects were observed 7 days' post-vaccination, the local and systemic reactions of preliminary test participants were recorded until day 28. There was no placebo group in this study. Blood samples were taken for serological testing before vaccination and 28 days' post-vaccination.

RESULTS

Twenty-eight days after vaccination, the seroconversion rates of experimental and control groups were H1N1 75.3% and 75.7%, H3N2 75.8% and 71.8%, B 70.7% vs. 69.4%, (P > 0.05). The antibody Geometric Mean Titer（GMT）of experimental and control groups were H1N1 (179.7, 182.4), H3N2 (584.0, 445.7), B (201.4,191.6). The protection rate of experimental and control groups was not statistically significant (H1N1: 86% vs. 87%, H3N2: 99% vs. 98%, B: 98% vs. 98%). Also, 95% confidence intervals of the protection rate difference between the experimental and the control group were H1N1: -0.1% (-4.1,3.8) %, H3N2: 0.3% (-1.0,1.7) % and B: 0.2% (-1.5,1.9) %; confidence intervals exceeded the limit of -5%. The rates of adverse reactions between experimental and control groups were 6.3% and 7.7% in local response reactions, and 19.5% and 18.0% in systemic reactions. Three hundred and twenty-seven adverse events (AEs) in 1200 (27.76%) subjects were reported within 28 d after vaccination. No serious adverse events occurred during the study.

CONCLUSIONS

The experimental vaccine three-antibody protection rate was non-inferior to the control vaccine. Our results demonstrated that the experimental vaccine achieved the primary immunogenic end point of the intended clinical protocol, as well as a secondary immunogenic end-point, with an acceptable level of safety. IRB approval for this study was issued under #2012Y0005 and registered as Clinical Trial No. NCT01551810.

Safety and immunogenicity of Bio Pox™, a live varicella vaccine (Oka strain) in Indian children: A comparative multicentric, randomized phase II/III clinical trial

Varicella or chickenpox is a highly contagious disease with a high secondary attack rate. Almost 30% of Indian adolescents lack protective antibodies against varicella, emphasizing the need of routine varicella immunization. The Oka VZV is a well-established, safe and efficacious vaccine strain that is highly immunogenic and produces lifelong protective immunity. The present multicentric, open label, randomized, controlled Phase II/III study, compared the Bio Pox™ (indigenous investigational vaccine) with a licensed vaccine, Varivax™ ^[a][a] Please note that this article refers to the product named VARIVAX as manufactured by Changchun Keygen Biological Products Ltd., China and marketed in India by VHB Life Sciences Limited, Mumbai, and not the product VARIVAX® owned by Merck Sharp & Dohme Corp., Rahway, New Jersey, USA. Merck Sharp & Dohme Corp. have asked us to make clear that the product manufactured by Changchun Keygen Biological Products Ltd. is unrelated to and is not sponsored, endorsed or otherwise authorised by Merck Sharp & Dohme Corp. , for its safety and immunogenicity profile in 252 healthy subjects in the age group of 1-12 y (cohort I: 6-12 years, II:1-6 years) in 3 tertiary medical institutions. Antibodies were measured by VZV Glycoprotein Enzyme Linked Immunoassay (IgG ELISA) kit. Seroconversion percentage in children having pre-vaccination anti VZV IgG titer <10 mIU/mL (< 5 gp ELISA units/mL) were 80% for Bio Pox™ and 77% for Varivax™ (p = 0.692). The seroconversion rate in the group receiving Bio Pox™ was non-inferior to the group that received Varivax™. There were mild local reactions for both the vaccines; none of the patient had fever or required hospitalization or medication. The Bio Pox™ was found to be safe and immunogenic in children against VZV infection.

Evaluation of Response to Hepatitis B Vaccination in Chronic Hemodialysis Patients

Background:

Hemodialysis (HD) patients are at an increased risk of acquiring hepatitis B virus (HBV) infection. Active HBV immunization in these patients is recommended. A response rate in HD patients is variable but generally lower than healthy individuals.

Objective:

The aim of this study is to assess the response of HD patients to the HBV vaccine and correlate response and long-term immunity to various clinical and biomedical factors.

Patients and Methods:

One hundred and one patients, with a mean age 48.7 ± 18.5 years, received 40 μg of HBV vaccine administered intramuscularly in the deltoid region at 0, 1, 2 and 6 months. The patients' responses to the vaccine were determined by measuring hepatitis B surface antibody (HBsAb) 6 weeks after the last injection and monitored thereafter at 3-month intervals.

Results:

Seventy-one patients (70.3%) mounted a response with HBsAb >10 mIU/ml 6 weeks following the fourth dose of vaccine, and thus were considered considered as adequate responders. Forty-nine (48.5%) patients mounted an excellent response with HBsAb >100 mIU/ml 6 weeks after the fourth dose. Thirty patients (29.7%) were nonresponders. Responders were significantly younger than nonresponders (P = 0.01). Gender, hemoglobin level, serum albumin, ferritin, parathyroid hormone level and hepatitis C virus infection had no effect on the response to the vaccine. Similarly, there was no difference in diabetic state and adequacy of HD between the two groups. Fifty-nine patients (88%) had persistent protective antibodies at 1 year, while eight (12%) lost such protection. Predictors of persistent immunity at 1 year were high HBsAb level at the completion of the vaccination regime and, to a lesser extent, young age.

Conclusion:

A 70% response rate to HBV vaccine was observed in the cohort of this study. Young age predicts a favorable response to HBV vaccine in HD patients. High (>100 mIU/ml) HBsAb levels achieved at vaccine completion predict persistent immunity at 1 year.

Infection with influenza A(H1N1)pdm09 during the first wave of the 2009 pandemic: Evidence from a longitudinal seroepidemiologic study in Dhaka, Bangladesh

Background

We determined influenza A(H1N1)pdm09 antibody levels before and after the first wave of the pandemic in an urban community in Dhaka, Bangladesh.

Methods

We identified a cohort of households by stratified random sampling. We collected baseline serum specimens during July‐August 2009, just prior to the initial wave of the 2009 pandemic in this community and a second specimen during November 2009, after the pandemic peak. Paired sera were tested for antibodies against A(H1N1)pdm09 virus using microneutralization assay and hemagglutinin inhibition (HI) assay. A fourfold increase in antibody titer by either assay with a titer of ≥40 in the convalescent sera was considered a seroconversion. At baseline, an HI titer of ≥40 was considered seropositive. We collected information on clinical illness from weekly home visits.

Results

We tested 779 paired sera from the participants. At baseline, before the pandemic wave, 1% overall and 3% of persons >60 years old were seropositive. After the first wave of the pandemic, 211 (27%) individuals seroconverted against A(H1N1)pdm09. Children aged 5‐17 years had the highest proportion (37%) of seroconversion. Among 264 (34%) persons with information on clinical illness, 191 (72%) had illness >3 weeks prior to collection of the follow‐up sera and 73 (38%) seroconverted. Sixteen (22%) of these 73 seroconverted participants reported no clinical illness.

Conclusion

After the first pandemic wave in Dhaka, one in four persons were infected by A(H1N1)pdm09 virus and the highest burden of infection was among the school‐aged children. Seroprevalence studies supplement traditional surveillance systems to estimate infection burden.

Antibody-Based Correlates of Protection Against Cholera Analysis of a Challenge Study in a Cholera-Naïve Population

Immunologic correlates of protection can be used to infer vaccine efficacy for populations in which challenge trials or field studies are infeasible. In a recent cholera challenge trial (WH Cohen et al, Clinical Infectious Disease 62: 1329-1335, 2016), 134 North American cholera-naïve volunteers were randomized to receive either the live, attenuated single-dose cholera vaccine CVD 103-HgR or placebo, and titers of vibriocidal antibodies against classical Inaba were assessed 10 days after treatment. Subsequent to the immunologic evaluation, each subject ingested a fixed quantity of virulent V. cholerae O1 El Tor Inaba. Data from this trial suggest that vaccine-induced increase in vibriocidal antibody titer prior to challenge is tightly linked with protection: 51/51 vaccinees with post-vaccination vibriocidal titers >= 2560 were protected against moderate/severe cholera, and 60/62 vaccinees who seroconverted, or experienced a 4-fold or greater increase in vibriocidal titer relative to pre-vaccination levels, were similarly protected. Atypically high vibriocidal titers were observed in some placebo subjects; protection was limited in these individuals and differed substantially from the level of protection experienced by vaccinees with the same post-vaccination titers. Since only 1 of 66 placebo recipients experienced seroconversion, seroconversion was found to be uniquely associated with vaccination and insensitive to the effects of factors that can cause titers to be elevated but are weakly associated with protection. Thus, vibriocidal seroconversion was found to be better than vibriocidal titer for inferring vaccine efficacy in cholera-naïve populations for which studies based upon exposure to V. cholerae are impractical.

A drop in the circulating concentrations of soluble receptor for advanced glycation end products is associated with seroconversion to autoantibody positivity but not with subsequent progression to clinical disease in children en route to type 1 diabetes

BACKGROUND

Advanced glycation end products (AGEs) and their interaction with the receptor for AGEs (RAGE) have been studied for their role in the pathogenesis and complications of type 1 diabetes. Decreased concentrations of soluble RAGE (sRAGE) have been reported in acute autoimmune inflammation. We set out to analyze the changes in sRAGE concentration during preclinical diabetes in children seroconverting to islet autoantibody positivity.

METHODS

We measured serum concentrations of sRAGE in 168 children who progressed to clinical disease and 43 children who turned positive for at least 2 diabetes-associated autoantibodies but remained nondiabetic. We analyzed the sRAGE before seroconversion in the first autoantibody-positive sample and annually thereafter until the diagnosis of type 1 diabetes or end of follow-up.

RESULTS

Both groups had similar sRAGE before seroconversion, but subsequently, sRAGE concentrations were lower (P < .001) in the progressors. The progressors had significantly higher sRAGE concentrations before than after seroconversion (P < .001). The nonprogressors did not experience a similar decrease. The sRAGE concentrations remained stable after seroconversion in both groups.

CONCLUSIONS

These data indicate that sRAGE may be involved in the initiation of beta-cell autoimmunity but not in the progression from beta-cell autoimmunity to clinical disease.

Presumptive diagnosis of leptospirosis before seroconversion: a review of 338 cases in Wallis and Futuna 2008 to 2015

Leptospirosis is a common condition in Wallis and Futuna, and the definitive diagnosis needs to be established urgently at the first patient consultation, which is usually one to two days after the onset of clinical signs. As a diagnostic aid, a composite index was established based on data from 338 patients seen by the Wallis and Futuna admissions services between 2008 and 2015. The data taken into account include: age and sex of the patient, their home island, the consultation period and the results of leukocytes, platelets, CRP, creatinine and GGT tests combined with 2 major clinical signs, headache and conjunctival suffusion. Then 5 threshold limits were defined for this index, which indicates from very low risk to almost certain biologically confirmed leptospirosis. Other febrile diseases responsible for thrombocytopenia are not found in Wallis and Futuna, which probably explains the good statistical qualities of this index with a value of area under the curve equal to 0.821.

Hepatitis E in blood donors: investigation of the natural course of asymptomatic infection, Germany, 2011

Asymptomatic hepatitis E virus (HEV) infections have been found in blood donors from various European countries, but the natural course is rarely specified. Here, we compared the progression of HEV viraemia, serostatus and liver-specific enzymes in 10 blood donors with clinically asymptomatic genotype 3 HEV infection, measuring HEV RNA concentrations, plasma concentrations of alanine/aspartate aminotransferase, glutamate dehydrogenase and bilirubin and anti-HEV IgA, IgM and IgG antibodies. RNA concentrations ranged from 77.2 to 2.19×10⁵ IU/mL, with viraemia lasting from less than 10 to 52 days. Donors showed a typical progression of a recent HEV infection but differed in the first detection of anti-HEV IgA, IgM and IgG and seropositivity of the antibody classes. The diagnostic window between HEV RNA detection and first occurrence of anti-HEV antibodies ranged from eight to 48 days, depending on the serological assay used. The progression of laboratory parameters of asymptomatic HEV infection was largely comparable to the progression of symptomatic HEV infection, but only four of 10 donors showed elevated liver-specific parameters. Our results help elucidate the risk of transfusion-associated HEV infection and provide a basis for development of screening strategies. The diagnostic window illustrates that infectious blood donors can be efficiently identified only by RNA screening.

Rural habitat as risk factor for hepatitis E virus seroconversion in HIV-infected patients: A prospective longitudinal study

Our objective was to determine the incidence and clinical manifestations of acute hepatitis E virus (HEV) in HIV-infected patients. A prospective longitudinal study including HIV-infected HEV-seronegative patients was conducted; HEV seroconversion (to IgG and/or IgM) was the main outcome variable. All patients were tested for HEV antibodies every 3-6 months. For patients who developed HEV seroconversion, a data collection protocol was followed to identify associated clinical manifestations and analytical alterations. A total of 627 patients (89.9%) were followed during a median of 11.96 months (IQR: 8.52-14.52 months) and formed the study population. Forty-one patients developed detectable anti-HEV antibodies (7.2 cases per 100 patients/year). Our study found a high incidence of HEV in HIV-infected patients in southern Spain strongly associated with a rural habitat.

Only rheumatoid factor-positive subset of anti-citrullinated peptide/protein antibody-negative rheumatoid arthritis may seroconvert to anti-citrullinated peptide/protein antibody-positive

AIM

Anti-citrullinated peptide/protein antibody (ACPA) has been reported to occur in about 60% of patients with early rheumatoid arthritis (RA), and about 80% in patients with established RA. While ACPA seroconversion is possible, previous reports have shown that it rarely occurs. We retrospectively determined the proportion of patients who underwent ACPA seroconversion and described the clinical characteristics of these cases.

METHODS

ACPA-negative RA patients who had undergone ACPA assessment more than once with an interval of 3 months or longer were investigated for ACPA seroconversion. The clinical characteristics of seroconverted patients were assessed.

RESULTS

In 149 ACPA-negative RA patients, only eight patients (5.4%) converted to ACPA-positive during follow-up. We found that all eight of the seroconverted cases were positive for rheumatoid factor (RF) and showed bone erosions by X-ray. Of 56 ACPA-negative RF-positive RA patients, 14.3% of them seroconverted to ACPA-positive. None of the ACPA-negative RF-negative RA patients seroconverted to ACPA-positive.

CONCLUSION

The proportion of total RA patients who experienced seroconversion from ACPA-negative to ACPA-positive was 5.4%. When ACPA-negative RA patients were subdivided into RF-negative and RF-positive subsets, only the RF-positive subset seroconverted to ACPA-positive. These results imply that RF-negative and RF-positive patients are distinct subsets within ACPA-negative RA patients.

The association of the HLA-A*24:02, B*39:01 and B*39:06 alleles with type 1 diabetes is restricted to specific HLA-DR/DQ haplotypes in Finns

BACKGROUND

We analysed the previously reported association of the HLA-A*24:02, B*18 and B*39 alleles with type 1 diabetes and diabetes associated autoimmunity in the Finnish population applying HLA-DR/DQ stratification.

MATERIALS & METHODS

Haplotype transmission was analysed in 2424 nuclear families from the Finnish Paediatric Diabetes Register. Survival analysis was applied to study the development of islet autoantibodies and further progression to clinical diabetes in the prospective follow-up cohort from the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) Study. The subjects were genotyped for specific HLA class I alleles by sequence-specific hybridization using lanthanide labelled nucleotide probes.

RESULTS

The HLA-B*39:06 allele was found almost exclusively on the (DR8)-DQB1*04 haplotype in which its presence changed the disease risk status of the whole haplotype from neutral to predisposing. The HLA-A*24:02 and the B*39:01 alleles increased the diabetes-associated risk of the DRB1*04:04-DQA1*03-DQB1*03:02 haplotype but the alleles were in linkage disequilibrium and no independent effect could be detected. Within the DIPP cohort, neither the A*24:02 nor the B*39:01 allele were associated with seroconversion but were in contrast associated with increased progression from seroconversion to clinical disease.

DISCUSSION & CONCLUSIONS

The independent predisposing effect of the HLA-B*39:06 allele with type 1 diabetes was confirmed in the Finnish population but the association of the A*24:02 and B*39:01 alleles remained inconclusive whilst both A*24:02 and B*39:01 affected the progression rate from seroconversion to autoantibody positivity to overt type 1 diabetes.

The prevalence and determinants of HIV seroconversion among booked ante natal clients in the University of Uyo teaching hospital, Uyo Akwa Ibom State, Nigeria

INTRODUCTION

The Prevention of Mother to Child transmission (PMTCT) of HIV, an important intervention in the fight against HIV/AIDS can only be of benefit if the HIV status of the mother is known. Unfortunately, some women receive HIV counseling and testing (HCT) during the window period or prior to new infection in pregnancy and therefore, miss-out on the gains of PMTCT. A repeat HIV test would identify this later seroconversion and ensure early intervention. This study aimed at determining the prevalence of HIV seroconversion during pregnancy and assessing the factors associated with HIV seroconversion in clients who attended ante-natal clinic (ANC) in University of Uyo Teaching Hospital, Uyo.

METHODS

A descriptive cross-sectional design was used to study 502 HIV negative clients who consecutively presented for ANC in the University of Uyo Teaching Hospital Uyo over a 3 months period (July -September 2013).

RESULTS

Fifteen (3%) of the 502 women who were HIV negative at booking visit tested positive (seroconverted) to HIV. Determinants of seroconversion at multivariate level were age bracket of 25-29 years (OR: 3.20; 95%CI: 2.39-4.29) clients' partners who had sexually transmitted infections, as evidenced by penile discharge (OR: 0.09; 95%CI: 0.01-0.45); Clients in polygamous setting (OR: 3.98; CI: 1.64-9.65); those taking alcohol (OR: 0.12; CI: 0.20-0.80) and those with partners taking recreational drugs (OR: 0.05, 95%CI: 0.002-0.995).

CONCLUSION

The study revealed a high seroconversion rate. Re-screening of pregnant women after the booking HCT is a very cost effective and beneficial strategy for the elimination of mother to child transmission of HIV.

Signs or Symptoms of Acute HIV Infection in a Cohort Undergoing Community-Based Screening

We analyzed signs and symptoms in 90 patients diagnosed with acute HIV infection in a community-based program that offered universal HIV-1 nucleic acid amplification testing. Forty-seven (52%) patients reported ongoing signs or symptoms at the time of testing. Another 25 (28%) reported signs or symptoms that had occurred during the 14 days before testing.

Incidence of syphilis seroconversion among HIV-infected persons in Asia: results from the TREAT Asia HIV Observational Database

INTRODUCTION

Outbreaks of syphilis have been described among HIV-infected men who have sex with men (MSM) in Western communities, whereas reports in Asian countries are limited. We aimed to characterize the incidence and temporal trends of syphilis among HIV-infected MSM compared with HIV-infected non-MSM in Asian countries.

METHODS

Patients enrolled in the TREAT Asia HIV Observational Database cohort and with a negative non-treponemal test since enrolment were analyzed. Incidence of syphilis seroconversion, defined as a positive non-treponemal test after previously testing negative, was evaluated among patients at sites performing non-treponemal tests at least annually. Factors associated with syphilis seroconversion were investigated at sites doing non-treponemal testing in all new patients and subsequently testing routinely or when patients were suspected of having syphilis.

RESULTS

We included 1010 patients from five sites that performed non-treponemal tests in all new patients; those included had negative non-treponemal test results during enrolment and subsequent follow-ups. Among them, 657 patients were from three sites conducting regular non-treponemal testing. The incidence of syphilis seroconversion was 5.38/100 person-years (PY). Incidence was higher in MSM than non-MSM (7.64/100 PY vs. 2.44/100 PY, p<0.001). Among MSM, the incidence rate ratio (IRR) for every additional year from 2009 was 1.19 (p=0.051). MSM status (IRR 3.48, 95% confidence interval (CI) 1.88-6.47), past syphilis diagnosis (IRR 5.15, 95% CI 3.69-7.17) and younger age (IRR 0.84 for every additional 10 years, 95% CI 0.706-0.997) were significantly associated with syphilis seroconversion.

CONCLUSIONS

We observed a higher incidence of syphilis seroconversion among HIV-infected MSM and a trend to increasing annual incidence. Regular screening for syphilis and targeted interventions to limit transmission are needed in this population.

Seroevidence for a High Prevalence of Subclinical Infection With Avian Influenza A(H5N1) Virus Among Workers in a Live-Poultry Market in Indonesia

Background. In Indonesia, highly pathogenic avian influenza A(H5N1) virus has become endemic in poultry and has caused sporadic deadly infections in human. Since 2012, we have conducted fixed-point surveillance of avian influenza viruses at a live-poultry market in East Java, Indonesia. In this study, we examined the seroprevalence of avian influenza A(H5N1) virus infection among market workers.

Methods. Sera were collected from 101 workers in early 2014 and examined for antibody activity against avian A(H5N1) Eurasian lineage virus by a hemagglutination-inhibition (HI) assay.

Results. By the HI assay, 84% of the sera tested positive for antibody activity against the avian virus. Further analysis revealed that the average HI titer in 2014 was 2.9-fold higher than in 2012 and that seroconversion occurred in 44% of paired sera (11 of 25) between 2012 and 2014. A medical history survey was performed in 2016; responses to questionnaires indicated that none of workers had had severe acute respiratory illness during 2013.

Conclusions. This study provides evidence of a high prevalence of avian A(H5N1) virus infection in 2013 among workers at a live-poultry market. However, because no instances of hospitalizations were reported, we can conclude the virus did not manifest any clinical symptoms in workers.

Assessment of a cytomegalovirus serology dual-testing strategy in hematopoietic stem cell transplant recipients

BACKGROUND

Accurate determination of recipient cytomegalovirus (CMV) serostatus before allogeneic hematopoietic stem cell transplantation (HSCT) is critical, as it is the most important predictor of post-transplant CMV infection and remains associated with non-relapse mortality. The purpose of this study was to assess a recipient dual-testing strategy before HSCT.

METHODS

CMV serologic testing was performed before allogeneic HSCT using 2 different assays: reference laboratory (RL) and American Red Cross (ARC). In all cases, blood samples were obtained for RL testing either before ARC testing (median 130 days before HSCT [range 12-2594]) or at the same time (median 25 days before HSCT [range 8-129]). The results of serologic testing were correlated with CMV viremia post HSCT.

RESULTS

Of 287 recipients evaluated, 76 (26.5%) had discordant results, of which 74 (97.4%) tested RL-/ARC+. Ten had RL and ARC testing performed on simultaneously obtained samples, 3 of which (30%) were discordant (3 [100%] RL-/ARC+). Acute myeloid leukemia and receipt of blood product transfusion in the interval between testing were associated with RL-/ARC+ discordance. Correlation with viremia after HSCT suggested that RL-/ARC+ discordance was caused by detection of anti-CMV immunoglobulin transferred in transfused blood products and reduced specificity of the ARC assay.

CONCLUSION

CMV-seronegative hematopoietic stem cell transplant recipients may be misclassified as seropositive if testing is performed after receipt of blood products or when using assays optimized for sensitivity at the expense of specificity. This misclassification may negatively affect post-HSCT outcomes for individual patients and studies that rely on accurate CMV serology reporting.

Long-term follow up of peginterferon-α-2a treatment of hepatitis B e-antigen (HBeAg) positive and HBeAg negative chronic hepatitis B patients in phase II and III studies

AIM

We analyzed the 5-year post-treatment response to peginterferon α-2a (PEG IFN-α-2a) in hepatitis B e-antigen (HBeAg) positive and negative chronic hepatitis B patients.

METHODS

One hundred and thirty-seven chronic hepatitis B (CHB) patients receiving 90 μg or 180 μg of PEG IFN-α-2a for 24 or 48 weeks in phase II or III studies were enrolled in the study, including 100 HBeAg positive patients and 37 HBeAg negative patients; 121 patients (88.4%) had genotype C.

RESULTS

Of the 137 patients, 94 received additional antiviral therapy because of viral reactivation and 43 did not receive any additional antiviral treatment during follow up. Five years upon PEG IFN-α-2a treatment, 32 patients (23.4%) who did not receive any additional antiviral agent after PEG IFN-α-2a therapy achieved a good response (normal serum alanine aminotransferase, low-level hepatitis B virus [HBV] DNA, and HBeAg negativity). Female sex and low HBV DNA levels by the end of treatment were independently associated with favorable 5-year post-treatment responses. Forty-eight-week administration of PEG IFN-α-2a showed a better response (26.4%) than 24-week administration (18.0%). Six patients (4.3%), four males and two females, cleared hepatitis B surface antigen (HBsAg) during the 5-year follow-up period.

CONCLUSION

The 48-week administration of PEG IFN-α-2a achieved better biochemical and virological responses than the 24-week administration, particularly in younger females. The 5-year post-treatment response rate was 23.4%; however, more than two-thirds of the patients received additional antiviral therapy because of viral reactivation after PEG IFN-α-2a treatment. HBsAg clearance was noted in six patients (4.3%). PEG IFN-α-2a is effective in young female patients.