Cumulative incidence and diagnosis of SARS-CoV-2 infection in New York

PURPOSE

New York State (NYS) is an epicenter of the SARS-CoV-2 pandemic in the United States. Reliable estimates of cumulative incidence in the population are critical to tracking the extent of transmission and informing policies.

METHODS

We conducted a statewide seroprevalence study in a 15,101 patron convenience sample at 99 grocery stores in 26 counties throughout NYS. SARS-CoV-2 cumulative incidence was estimated from antibody reactivity by first poststratification weighting and then adjusting by antibody test characteristics. The percent diagnosed was estimated by dividing the number of diagnoses by the number of estimated infection-experienced adults.

RESULTS

Based on 1887 of 15,101 (12.5%) reactive results, estimated cumulative incidence through March 29 was 14.0% (95% confidence interval [CI]: 13.3%-14.7%), corresponding to 2,139,300 (95% CI: 2,035,800-2,242,800) infection-experienced adults. Cumulative incidence was highest in New York City 22.7% (95% CI: 21.5%-24.0%) and higher among Hispanic/Latino (29.2%), non-Hispanic black/African American (20.2%), and non-Hispanic Asian (12.4%) than non-Hispanic white adults (8.1%, P < .0001). An estimated 8.9% (95% CI: 8.4%-9.3%) of infections in NYS were diagnosed, with diagnosis highest among adults aged 55 years or older (11.3%, 95% CI: 10.4%-12.2%).

CONCLUSIONS

From the largest U.S. serosurvey to date, we estimated >2 million adult New York residents were infected through late March, with substantial disparities, although cumulative incidence remained less than herd immunity thresholds. Monitoring, testing, and contact tracing remain essential public health strategies.

Prevalence of Zika virus neutralizing antibodies in healthy adults in Vietnam during and after the Zika virus epidemic season: a longitudinal population-based survey

Background

Between 2016 and 2019, 265 cases of Zika virus (ZIKV) infection were reported in Vietnam, predominantly in southern Vietnam. In 2016, a case of ZIKV-associated microcephaly was confirmed in the Central Highlands, and several members of the infant’s family were confirmed to be infected with ZIKV. The study aims to determine the level of immunity to ZIKV in the general population of the ZIKV epidemic region.

Methods

A total of 879 serum samples were collected from 801 participants between January 2017 and July 2018, during and after the ZIKV epidemic in Vietnam. The samples were tested for anti-ZIKV immunoglobulin M (IgM) and immunoglobulin G (IgG), and anti-dengue virus (DENV) IgG antibodies using enzyme-linked immunosorbent assays (ELISA). Plaque-reduction neutralization test (PRNT) for ZIKV was performed on all samples, and for DENV on the samples that ZIKV neutralizing antibody positive.

Results

A total of 83 (10.3%) participants had anti-ZIKV IgM. Of the 83, 6 were confirmed to be ZIKV antibodies positive using PRNT and anti-ZIKV IgG ELISA. Of the 718 participants who were anti-ZIKV IgM negative, a further 3 cases were confirmed as positive for antibodies against ZIKV. Of the 9 participants with ZIKV infection, 5 lived in the same village as the infant with ZIKV-associated microcephaly and the other 4 lived in 2 neighboring communes. Repeat samples were collected from the 83 ZIKV IgM positive participants 1.5 years after the first collection. No new cases of ZIKV infection were detected. In addition, 2 of 3 participants with anti-ZIKV NS1 IgG demonstrated a 4- to 8-fold increase in ZIKV neutralizing antibody titer.

Conclusions

ZIKV was present in the area around Krong Buk, with the rate of ZIKV-specific antibodies was 1.1% in the community since at least 2016. While the low levels of circulation together with low seroprevalence suggests a limited outbreak in the region, the results also reflect on low levels of protective immunity to Zika within the population. These results provide a better understanding of the current ZIKV epidemic status in the region and demonstrate a need for implementation of more effective ZIKV infection control measures.

Hepatitis E Virus Infection in an Italian Cohort of Hematopoietic Stem Cell Transplantation Recipients: Seroprevalence and Infection

Chronic hepatitis E virus (HEV) infection in hematopoietic stem cell transplantation (HSCT) recipients is an emerging threat. The aim of this study was to provide data on the HEV burden in an Italian cohort of HSCT recipients and analyze risk factors for HEV seropositivity. This retrospective study reports data from 596 HSCT recipients compiled between 2010 and 2019. It included patients who underwent transplantation between 2010 and 2015 for whom pretransplantation (n = 419) and post-transplantation (n = 161) serum samples were available and tested retrospectively, as well as patients in whom prospective HEV testing was performed during the standard care: pre-HSCT IgG screening in 144, pre-HSCT HEV-RNA screening in addition to IgG screening in 60, and HEV-RNA testing in case of clinical suspicion of HEV infection in 59 (26 of whom were also included in the IgG screening cohorts). The rate of pre-HSCT HEV-IgG positivity was 6.0% (34 of 563). Older age was an independent risk factor for seropositivity (P = .039). None of the 34 HEV-IgG-positive patients had detectable HEV-RNA. One case of transient HEV-RNA positivity pre-HSCT was identified through screening. Two patients were diagnosed with chronic HEV hepatitis, and 1 patient was successfully treated with ribavirin. The burden of HEV infection in HSCT recipients in Italy is limited, and pre-HSCT screening appears to be of no benefit. Timely diagnosis of HEV infection with HEV-RNA is mandatory in cases of clinical suspicion.

Measles Outbreak in a Rural Population in Bahar District, Hamadan Province, West of Iran in 2018

Background: Measles is in elimination phase in Iran. Following occurrence of two cases of measles in two children under six years old with the history of measles immunization in one of the villages affiliated to Bahar District, west of Hamadan Province, northwest of Iran, this study was conducted to determine the immunity status of people living in the village affected by the measles outbreak in spring of 2018.

Study design: A cross-sectional (descriptive-analytical) study.

Methods: Overall, 272 populations of 0-40 yr old in the village affected by outbreak were enrolled. Multistage sampling was used for choosing participants. The data collection tool was a researcher-made checklist used to collect epidemiological data including demographic characteristics and vaccination status. Blood samples were taken from them and sent to the measles reference laboratory for IgG testing. The amount of optical density (OD) greater than 0.2 was considered as positive and less than 0.1 negative, respectively.

Results: The mean age of the study population was 17.4 ±11.8 yr and the sex ratio was almost the same. Levels of antibodies against measles were positive in 63.24%, intermediate in 12.5% and negative in 24.26%. There was no significant difference between the immunity status of the subjects with gender (P=0.236) and age group (P=0.113). Pearson correlation results showed that in males there was a significant positive correlation between the age of the participants and the serum IgG level (r = 0.26, P=0.003).

Conclusion: Measles immunity in communities is not sufficient to prevent outbreaks and small epidemics, and it is recommended that periodically, serological assessments carried out at community level and especially at high-risk groups.

Seroprevalence of mumps in healthcare workers in South Korea

Mumps is contagious disease and maintaining immunity to mumps in healthcare worker (HCW) is important for preventing transmission in the hospital. We evaluated the seroprevalence of mumps in HCWs in a tertiary care hospital in Republic of Korea. A total of 6,055 HCWs born between 1950 and 1995 underwent antibody testing. The overall seropositivity rate of mumps was 87% (95% confidence interval, 86%-87%). Our data indicates that, in Korean HCWs, testing for mumps antibody followed by mumps vaccination is more appropriate than routine mumps vaccination without testing for mumps antibody.

Seropositive rate of the anti-hepatitis A immunoglobulin G antibody in maintenance hemodialysis subjects from two hospitals in Korea

BACKGROUND/AIMS

Hepatitis A virus (HAV) is a self-limiting infectious disease, but 1% of subjects develop fulminant hepatitis. The prevalence of the anti-HAV immunoglobulin G (IgG) antibody in hemodialysis subjects in Korea remains unknown. The purpose of this study was to describe and compare the seropositive rate of anti-HAV antibody among hemodialysis subjects in two hospitals according to age group.

METHODS

A total of 170 hemodialysis subjects were evaluated for the seropositive rate of the anti-HAV IgG antibody and its titer.

RESULTS

Of the 170 maintenance hemodialysis subjects in two hospitals (Kangnam 92 vs. Chuncheon 78), 79 (46.5%) were male. The mean age was 53.2 years old, and 94.1% of the subjects were over 40 years old. The median vintage of hemodialysis was 29.0 months. Anti-HAV antibody was found in 163 subjects (95.9%), with no significant difference between the two areas (Kangnam 97.8% [n = 90] vs. Chuncheon 93.6% [n = 73]). Subjects younger than 40 years old showed a seropositive rate of 50%, while the seropositive rate increased with age for subjects aged 40 or older (p for trend < 0.001). Seropositive subjects from Kangnam showed a higher anti-HAV antibody titer than those from Chuncheon (median: Kangnam 14.2 vs. Chuncheon 11.7). Only age influenced seropositivity. The only factor that influenced the antibody level was the location of hospital (p < 0.001).

CONCLUSION

The seropositive rate of the anti-HAV antibody in hemodialysis subjects was 95%, which is similar to findings in the general population. Active immunization against hepatitis A is strongly recommended for hemodialysis subjects under 40 years of age after anti-HAV testing.

Estimated dengue force of infection and burden of primary infections among Indian children

Background

Comprehensive, age-stratified dengue surveillance data are unavailable from India and many more dengue cases occur than are reported. Additional information on dengue transmission dynamics can inform understanding of disease endemicity and infection risk.

Methods

Using age-stratified dengue IgG seroprevalence data from 2556 Indian children aged 5–10 years, we estimated annual force of infection (FOI) at each of 6 sites using a binomial regression model. We estimated the ages by which 50 and 70% of children were first infected; and predicted seroprevalence in children aged 1–10 years assuming constant force-of-infection. Applying these infection rates to national census data, we then calculated the number of primary dengue infections occurring, annually, in Indian children.

Results

Annual force-of-infection at all sites combined was 11.9% (95% CI 8.8–16.2), varying across sites from 3.5% (95% CI 2.8–4.4) to 21.2% (95% CI 18.4–24.5). Overall, 50 and 70% of children were infected by 5.8 (95% CI 4.3–7.9) and 10.1 (95% CI 7.4–13.7) years respectively. In all sites except Kalyani, > 70% of children had been infected before their 11th birthday, and goodness-of-fit statistics indicated a relatively constant force-of-infection over time except at two sites (Wardha and Hyderabad). Nationwide, we estimated 17,013,527 children (95% CI: 14,518,438- 19,218,733), equivalent to 6.5% of children aged < 11 years, experience their first infection annually.

Conclusions

Dengue force-of-infection in India is comparable to other highly endemic countries. Significant variation across sites exists, likely reflecting local epidemiological variation. The number of annual primary infections is indicative of a significant, under-reported burden of secondary infections and symptomatic episodes.

Trial registration

Registered retrospectively with clinicaltrials.gov (NCT01477671; 18/11/2011) and clinical trials registry of India (ctri.nic.in; CTRI/2011/12/002243; 15/12/2011). Date of enrollment of 1st subject: 22/9/2011.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-7432-7) contains supplementary material, which is available to authorized users.

A study of hepatitis A virus seropositivity among children aged between 1 and 5 years of age: Implications for universal immunization

Background

Hepatitis A virus (HAV) causes an enterically transmitted viral disease mainly affecting children and endemic in many developing countries, including India. There is an epidemiological shift with an increased incidence of symptomatic cases among children. This study was conducted to assess the seroprevalence of HAV among young children aged below 5 years and the need for universal immunization.

Method

This cross-sectional study was conducted at two tertiary care hospitals in Northern India, from Apr 2014 to Jul 2015, among healthy children aged between 1 and 5 years. The sample size was calculated based on the prevalence of HAV seropositivity of 40% among children aged <10 years [16-60%] and alpha error of 5%. Analysis of serum IgG against HAV was performed by enzyme-linked immunosorbent assay method, and results were analyzed.

Results

A total of 1084 children aged between 12 and 60 months were enrolled, with male-to-female ratio of 1.86:1. A total of 471 children (43.5%) were found to be positive for IgG against HAV. The seroprevalence of HAV was lower among younger children aged 12-23 months (odds ratio [OR] = 0.73, 95% confidence interval [CI] = 0.52-0.87, p = 0.03), which was statistically significant. Seropositivity of HAV was lower among boys and families consuming safe drinking water and having improved sanitation facilities.

Conclusion

The study observed lower seropositivity against HAV among younger children, making them susceptible of contracting the disease. Possible underlying risk factors were younger age, unsafe drinking water, poor sanitation, and low education status of parents. Therefore, vaccination may be recommended as optional vaccine at one year of age, along with improved public health efforts for safe drinking water, hygiene practices, and food safety.

Seroprevalence of Histoplasmosis in Somali, Burmese, and Hmong Refugees Residing in Thailand and Kenya

Histoplasmosis is known to be endemic to the Midwestern United States, but cases have been reported throughout much of the world. Somali, Hmong, and Burmese (ethnically Karen) persons make up some of the largest refugee populations coming the United States in recent years. Yet, information about risk of Histoplasma capsulatum infection amongst these populations is limited. This study used the CDC Migrant Serum Bank to test ~100 samples from each of Somali, Burmese, and Hmong U.S.-bound refugees. Samples were tested by enzyme immunoassay for Histoplasma capsulatum IgG. Overall 1% (2/299) of refugee serum samples were positive for H. capsulatum IgG. One of 99 samples obtained from Hmong refugees was positive, and the other positive sample came from among 100 Burmese refugee samples. H capsulatum IgG positivity was detected at low levels in Hmong and Burmese refugees. No IgG positivity was detected among 100 Somali refugees.

Mucosal and cutaneous Human Papillomavirus seroprevalence among adults in the prevaccine era in Germany - Results from a nationwide population-based survey

BACKGROUND

Human Papillomavirus (HPV) vaccination of girls was introduced in Germany in 2007. However, data on the distribution of vaccine-relevant HPV types in the general population in Germany in the prevaccine era are limited.

METHODS

Serum samples collected during the German National Health Interview and Examination Survey 1998 (GNHIES98), a nationally representative study including men and women aged 18-79 years, were tested for antibodies to 19 mucosal and cutaneous HPV types. Multivariable regression models were developed to identify associations between demographic and behavioral characteristics and HPV seropositivity.

RESULTS

Of the 6517 serum samples tested, almost a quarter was seropositive for at least one of the nine HPV vaccine types with no clear age-pattern. HPV-6 and HPV-59 were the most common mucosal types, while HPV-1 and HPV-4 were the most common cutaneous HPV types. Factors independently associated with HPV-16 seroprevalence were seropositive to other sexually transmitted infections and lifetime number of sex partners, as well as urbanity (only among females).

CONCLUSIONS

Prevalence of naturally acquired antibodies to HPV types which can be prevented by vaccination is high in both sexes and all age groups. These data can serve as baseline estimates to evaluate the population-level impact of the current vaccination strategy.

Sero Conversion of Viral Hepatitis among End Stage Renal Disease Patients on Hemodialysis in Kashmir: Results of a Prospective Study

BACKGROUND

The seroconversion is a significant health concern in patients with end-stage renal disease undergoing hemodialysis particularly in high endemic zones of HBV and HCV.

PATIENTS AND METHODS

This prospective study was conducted from January 2009 to April 2018 at Sheri Kashmir Institute of Medical Sciences, Srinagar, Kashmir. A cohort of 459 end-stage renal disease patients on hemodialysis was enrolled from four dialysis centres and followed in a longitudinal manner. Their seroconversion rates, risk factors were studied. Positive patients were treated and followed up.

RESULTS

This study demonstrated HBV seroconversion rate of 7.4 % (n = 34) and HCV seroconversion rate of 10% (n = 46) in a cohort of 459 patients on hemodialysis attending four dialysis centres of Kashmir. Patients with diabetes mellitus outnumbered in seroconversion rates of (43.75%) followed by patients with glomerulonephritis (23.75%). Of 15 patients who had undergone renal transplantation 10 (66.67%), patients had seroconversion on hemodialysis which was statistically significant (P < 0.001). Patients who were dialysed at multiple HD centres had significant seroconversion than those who followed up at a single center. Seroconversion was associated with longer duration of dialysis (80.30 ± 30.92 vs 61 ± 9.41months, P < 0.000). HBV vaccination of the ESRD patient on hemodialysis was significantly protective against seroconversion (P = 0.000).

CONCLUSIONS

Hepatitis B vaccination, stringent precautions in all dialysis centres could help to reduce the high seroconversion rates which have a high financial burden on ESRD patients. Intense health education to both patients and medical staff will be beneficial to lower the seroconversion rates.

Leptospirosis and Workplace Environmental Risk Factors among Cattle Farmers in Northeastern Malaysia

BACKGROUND

Leptospirosis is an emerging zoonosis and its occurrence has been reported to be rising globally. The environment plays an important role in the survival of Leptospira and determines the risk of infection. Those who were exposed to and had contact with contaminated environment through their occupational, recreational and other activities can be infected with the organism.

OBJECTIVE

To determine the seroprevalence of leptospirosis among cattle farmers, prevalence of pathogenic Leptospira, and the workplace environmental risk factors for leptospirosis among cattle farmers in northeastern Malaysia.

METHODS

A cross-sectional study involving 120 cattle farmers was conducted. The participants answered an interviewer-guided questionnaire that consisted of sociodemographic and workplace environment characteristics questionnaire, before having their blood sample taken for microscopic agglutination test (MAT). Seropositivity was determined using a cut-off titer of ≥1:100. 248 environmental samples were also collected from the cattle farms for polymerase chain reaction (PCR).

RESULTS

The overall seroprevalence of leptospiral antibodies was 72.5% (95% CI 63.5% to 80.1%) and the prevalence of pathogenic Leptospira in the cattle farms environment was 12.1% (95% CI 8.4% to 17.0%). The independent factors associated with seropositivity of leptospirosis among cattle farmers were positive pathogenic Leptospira in the environment (Adj OR 5.90, 95% CI 1.34 to 26.01) and presence of garbage dumping in the farm (Adj OR 2.40, 95% CI 1.02 to 5.65).

CONCLUSION

Preventing leptospirosis incidence among cattle farmers necessitates changes in work environment. Identifying modifiable factors may also contribute to the reduction of infection.

Seroprevalence and risk factors of recent infection with hepatitis E virus during an acute outbreak in an urban setting in Chad, 2017

BACKGROUND

From September 2016-April 2017, Am Timan, Chad, experienced a large HEV outbreak in an urban setting with a limited impact in terms of morbidity and mortality. To better understand HEV epidemiology in this context, we estimated the seroprevalence of anti-HEV antibodies (IgM and IgG) and assessed the risk factors for recent HEV infections (positive anti-HEV IgM) during this outbreak.

METHODS

A serological survey using simple random sampling was implemented in Am Timan at the tail-end of the outbreak (sample size aim = 384 household). Household members provided us with blood samples and household heads answered questions around water, sanitation and hygiene practices and animal ownership. Blood samples were tested for HEV IgG and IgM antibodies using Enzyme-Immune-Assay (EIA). We calculated weighted prevalence estimates and prevalence ratios (PRs) for possible risk factors for recent infection using multivariate Cox regression.

RESULTS

We included 241 households (1529 participants). IgM prevalence decreased with age: 12.6% (< 5 years) to 4.3% (> 15 years). IgG prevalence increased with age: 23.5% (< 5 years) to 75.9% (> 15 years). Risk factors for recent HEV infections included: sharing the sanitation facility with other HHs (PR 1.72; 95%CI: 1.08-2.73), not systematically using soap for HW (PR 1.85; 95%CI: 1.30-2.63) and having animals sleeping inside the compound (PR 1.69; 95%CI: 1.15-2.50).

CONCLUSIONS

Evidence suggests that Am Timan was already highly endemic for HEV before the outbreak, potentially explaining the limited extent of the outbreak. Recent infection with HEV was linked to household level exposures. Future HEV outbreak response must include ensuring access to safe water, and reducing household level transmission through active hygiene and sanitation promotion activities.

Hepatitis C virus seroprevalence and prevalence of chronic infection in the adult population in Ireland: a study of residual sera, April 2014 to February 2016

Robust data on hepatitis C virus (HCV) population prevalence are essential to inform national HCV services. In 2016, we undertook a survey to estimate HCV prevalence among the adult population in Ireland. We used anonymised residual sera available at the National Virus Reference Laboratory. We selected a random sample comprising persons ≥ 18 years with probability proportional to the general population age-sex distribution. Anti-HCV and HCV Ag were determined using the Architect anti-HCV and HCV Ag assays. Fifty-three of 3,795 specimens were seropositive (age-sex-area weighted seroprevalence 0.98% (95% confidence interval (CI): 0.73–1.3%)). Thirty-three specimens were HCV-antigen and antibody-positive (age-sex-area weighted prevalence of chronic infection 0.57% (95% CI: 0.40–0.81%)). The prevalence of chronic infection was higher in men (0.91%; 95% CI: 0.61–1.4%), in specimens from the east of the country (1.4%; 95%CI: 0.99–2.0%), and among persons aged 30–39 years and 40–49 years (1.1% (95% CI: 0.59–2.0%) and 1.1% (95% CI: 0.64–1.9%) respectively). Ireland ranks at the lower end of the spectrum of prevalence of chronic HCV infection internationally. Men born between 1965 and 1984 from the east of the country have the highest rate of chronic HCV infection.

Estimation of expected dengue seroprevalence from passive epidemiological surveillance systems in selected areas of Argentina: A proxy to evaluate the applicability of dengue vaccination

BACKGROUND

Current recommendations about dengue vaccination by the World Health Organization depend on seroprevalence levels and serological status in populations and individuals. However, seroprevalence estimation may be difficult due to a diversity of factors. Thus, estimation through models using data from epidemiological surveillance systems could be an alternative procedure to achieve this goal.

OBJECTIVE

To estimate the expected dengue seroprevalence in children of selected areas in Argentina, using a simple model based on data from passive epidemiological surveillance systems.

METHODS

A Markov model using a simulated cohort of individuals from age 0 to 9 years was developed. Parameters regarding the reported annual incidence of dengue, proportion of inapparent cases, and expansion factors for outpatient and hospitalized cases were considered as transition probabilities. The proportion of immune population at 9 years of age was taken as a proxy of the expected seroprevalence, considering this age as targeted for vaccination. The model was used to evaluate the expected seroprevalence in Misiones and Salta provinces and in Buenos Aires city, three settings showing different climatic favorability for dengue.

RESULTS

The estimates of the seroprevalence for the group of 9-year-old children for Misiones was 79% (95%CI:46-100%), and for Salta 22% (95%CI:14-30%), both located in northeastern and northwestern Argentina, respectively. Buenos Aires city, from central Argentina, showed a likely seroprevalence of 7% (95%CI: 3-11%). According to the deterministic sensitivity analyses, the parameter showing the highest influence on these results was the probability of inapparent cases.

CONCLUSIONS

This model allowed the estimation of dengue seroprevalence in settings where this information is not available. Particularly for Misiones, the expected seroprevalence was higher than 70% in a wide range of scenarios, thus in this province a vaccination strategy directed to seropositive children of >9 years should be analyzed, including further considerations as safety, cost-effectiveness, and budget impact.

Seroprotection against Vaccine-Preventable Diseases amongst Health Care Workers in a Community Hospital, Qatar

Background:

Health care workers (HCW) are at high risk of contracting various infectious diseases and play a dual role in the transmission of infections in health care facilities.

Objective:

To determine the seroprotection against hepatitis B, measles, rubella, and varicella among HCWs in a community hospital in Qatar.

Methods:

This is a cross-sectional survey conducted in a 75-bed community hospital in Dukhan, Qatar. From August 2012 to December 2015, 705 HCWs were tested for the presence of IgG antibodies for measles, rubella, and varicella, and also for hepatitis B surface antigen (HBsAg). They were also asked about previous history of hepatitis B vaccination.

Results:

595 (84.4%) HCWs received a full hepatitis B vaccination schedule; 110 (15.6%) received a single dose. The full schedule was reported with higher frequency by nurses (90.2%) compared to physicians (74.1%) or technicians (79.7%). Those aged ≥30 years (90.4%) and <20 years of work experience had received a full vaccination schedule more frequently than younger and less experienced HCWs. Female HCWs (87.8%) received full schedule more frequently than males (78.8%). 73.4% of the staff had seroprotection against heaptitis B, with the lowest anti-HBsAg titers observed in physicians (58.8%) compared with other categories; males (64.9%) were less protected than females. The seropositivity was 85.6%(95% CI 82.4% to 88.4%) for measles, 94.7% (95% CI 92.2% to 97.3%) for rubella, and 92.2% (95% CI 89.7% to 94.7%) for varicella.

Conclusion:

HCWs, particularly physicians, are not enough protected against hepatitis B. The seroprotection against measles, rubella, and varicella.

[A sero-epidemiological study of hepatitis E among general population in Shandong Province of China in 2014]

Objective: To analyze the sero-epidemiological characteristics of hepatitis E virus (HEV) in Shandong province, and thereby to provide evidence for the policy-making of hepatitis E prevention and control. Methods: The inhabitants aged between 1-59 years old were randomly selected to participate in the study by two-stage stratified random sampling method from 12 counties in Shandong province in October, 2014. Firstly two townships were selected from each county by probability proportional to size sampling (PPS) method. A total of 5 229 participants aged 1-59 years old were selected by stratified random sampling method. All the participants finished a questionnaire survey and a venous blood sample (3-5 ml) was collected from each to test anti-HEV IgG by enzyme-linked assay (ELISA). The weighted prevalence of anti-HEV IgG with different demographic characteristics was estimated. The variance of the positive rate of anti-HEV IgG was calculated by Taylor series linearization method, as well as its 95%CI. A statistical test was conducted to compare the rate of its 95%CI, and the results in the present study were compared with those in sero-survey in 2006. Results: A total of 5 229 subjects entered the final analysis in 2014. The overall weighed prevalence of anti-HEV IgG was 9.19% (95%CI: 6.18%-12.20%) among natural population in Shandong province, decreased by 19.88% in comparison with that in 2006 sero-survey (11.47%, 95%CI: 8.92%-14.02%). The prevalence increased with age increasing (χ(2trend)=288.11, P<0.001) in 2014, which was similar to the result in 2006 sero-survey. Except for 1-4 years old group, the prevalence of anti-HEV IgG in the other age groups were lower than it in the corresponding groups in 2006. The prevalence of anti-HEV IgG in urban (8.19%, 95%CI: 0.00-22.23%), rural areas (9.69%, 95%CI: 4.99%-14.38%), eastern areas (12.70%, 95%CI: 0.00-27.72%), central areas (4.74%, 95%CI: 0.00-9.91%) and western areas (9.32%, 95%CI: 0.69%-17.94%) in 2014 were all lower than the corresponding prevalences (11.39%, 95%CI: 8.17%-14.62%; 11.92%, 95%CI: 8.75%-15.08%; 22.77%, 95%CI: 14.99%-30.55%; 7.97%, 95%CI: 4.75%-11.20%; 10.59%, 95%CI: 6.37%-14.82%) in 2006 survey. The prevalence of anti-HEV IgG in coastal areas (16.56%, 95%CI: 12.94%-20.18%) and inland areas (7.63%, 95%CI: 5.16%-10.10%) in 2014 were lower than it in the corresponding areas (28.04%, 95%CI: 20.45%-35.64%; 9.50%, 95%CI: 7.31%-11.70%) in 2006 survey. The prevalence among peasant (11.98%, 95%CI: 8.20%-15.76%), worker (9.68%, 95%CI: 4.48%-14.88%), cadre (13.90%, 95%CI: 7.47%-20.33%), service provider (12.26%, 95%CI: 1.80%-22.73%) in 2014 survey were lower than it among the corresponding populations (13.76%, 95%CI: 10.15%-17.38%; 21.11%, 95%CI: 12.67%-29.55%; 17.81%, 95%CI: 7.63%-28.00%; 21.08%, 95%CI: 0.03%-42.12%) in 2006 survey. Conclusion: The prevalence of anti-HEV IgG has decreased in Shandong province in the recent years, but the epidemiological characteristics found no obvious changes. HEV susceptibility in natural population was generally high. Hepatitis E vaccines were recommended to be used in HEV high-risk population in the province.

The seroprevalence of Bartonella henselae in healthy adults in Korea

BACKGROUND/AIMS

Cat-scratch disease (CSD), caused by Bartonella henselae is one of the most common zoonosis. However, only several cases of B. henselae infection have been reported in Korea. This study investigated the seroprevalence of B. henselae in healthy adults and related risk factors.

METHODS

Serum samples from 300 healthy participants were analyzed using an immunoglobulin G immunof luorescence assay (IFA) for B. henselae isolated in Korea. Surveys on the risk factors for B. henselae infection were conducted simultaneously.

RESULTS

Of the participants, 47.7% and 15.0% raised dogs and cats, respectively. The overall seroprevalence of B. henselae was 15.0% (IFA titer ≥ 1:64). Participants who had raised cats showed 22.2% seropositivity against B. henselae, and those with no experience with cats showed 13.7% seroprevalence (p = 0.17). Participants who had cats as pets or been scratched by cats, showed 9.8% seropositivity against B. henselae (IFA titer ≥ 1:256). However, those who had not raised or been scratched by a cat showed 2.0% seropositivity (p = 0.015).

CONCLUSIONS

In Korea, the seroprevalence of B. henselae is higher than expected, suggesting that Bartonella infection due to B. henselae is not uncommon. Cats are proposed to play a more important role than dogs in transmission of CSD.

Cross-protection to new drifted influenza A(H3) viruses and prevalence of protective antibodies to seasonal influenza, during 2014 in Portugal

INTRODUCTION

Immune profile for influenza viruses is highly changeable over time. Serological studies can assess the prevalence of influenza, estimate the risk of infection, highlight asymptomatic infection rate and can also provide data on vaccine coverage. The aims of the study were to evaluate pre-existing cross-protection against influenza A(H3) drift viruses and to assess influenza immunity in the Portuguese population.

MATERIALS AND METHODS

We developed a cross-sectional study based on a convenience sample of 626 sera collected during June 2014, covering all age groups, both gender and all administrative health regions of Portugal. Sera antibody titers for seasonal and new A(H3) drift influenza virus were evaluated by hemagglutination inhibition assay (HI). Seroprevalence to each seasonal influenza vaccine strain virus and to the new A(H3) drift circulating strain was estimated by age group, gender and region and compared with seasonal influenza-like illness (ILI) incidence rates before and after the study period.

RESULTS

Our findings suggest that seroprevalences of influenza A(H3) (39.9%; 95% CI: 36.2-43.8) and A(H1)pdm09 (29.7%; 95% CI: 26.3-33.4) antibodies were higher than for influenza B, in line with high ILI incidence rates for A(H3) followed by A(H1)pdm09, during 2013/2014 season. Low pre-existing cross-protection against new A(H3) drift viruses were observed in A(H3) seropositive individuals (46%). Both against influenza A(H1)pdm09 and A(H3) seroprotection was highest in younger than 14-years old. Protective antibodies against influenza B were highest in those older than 65years old, especially for B/Yamagata lineage, 33.3% (95% CI: 25.7-41.9). Women showed a high seroprevalence to influenza, although without statistical significance, when compared to men. A significant decreasing trend in seroprotection from north to south regions of Portugal mainland was observed.

CONCLUSIONS

Our results emphasize that low seroprotection increases the risk of influenza infection in the following winter season. Seroepidemiological studies can inform policy makers on the need for vaccination and additional preventive measures.

Seroprevalence and geographical distribution of human T-lymphotropic virus type 1 among volunteer blood donors in endemic areas of Iran

Background

Human T-cell lymphotrophic virus type 1 (HTLV-1) has a worldwide distribution and it is endemic in some regions of Iran. One of the most important routes of HTLV-1 transmission is via transfusion of contaminated blood components. The risk of transmission through asymptomatic blood donors, particularly in endemic areas should be considered and appropriately managed. The main objective of this study was to determine the seroprevalence and description the geographic distribution of HTLV-1 among voluntary blood donors in Iran.

Methods

This retrospective study carried out using the data obtained from the main database of the seven blood transfusion centers of Iranian Blood Transfusion Organization between 2009 and 2013. The presence of anti-HTLV-1/2 antibodies were primarily assessed using Enzyme-linked Immunosorbent Assay. The Ab Kit assay, contain antigens for the screening of antibodies to HTLV type 1 and 2. So, it is expressed as HTLV 1/2 assay. Samples that were positive by the western blot confirmatory test were considered as definite positive HTLV-1 or HTLV-2 cases. The main socio-demographic variables were; age, gender, donation history and marital status. Descriptive and analytical statistics were used to summarize the gathered data. The chi-Square Statistical test was used to test the association between groups, P-value of less than 0.05 was considered significant.

Results

A total of 1864489 blood donations were evaluated. There were 1840 confirmed HTLV-1 positive donations (0.098%). None were positive for anti-HTLV-2. The overall HTLV-1 prevalence was 98.7 per 100,000 donations during the 5 year period. Seroprevalence was higher among females, married and older blood donors. The overall seropositivity among first time, regular and lapsed donors was, 0.29% (290/100000), 0.001% (1/100000) and 0.02% (20/100000) respectively. A significant difference was observed between regular and the first time (p <0.0001) and also between lapsed and regular blood donors (p <0.0001). Most of the HTLV-1 seropositive blood donors (175 per 100,000) were from northeastern regions. We observed a gradual decline in overall HTLV-1 prevalence during the course of the study, the prevalence rate decreased from 0.13% (130/100000) in 2009 to 0.07% (70/100000) in 2013.

Conclusions

The Seroprevalence of HTLV-1 among Iranian blood donors in the regions of our study still is considerable, but there is an obvious declining prevalence over the course of present study. Blood transfusion centers should continually evaluate the residual risk of infection in the country, especially in endemic areas.

Seroprevalence of Poliovirus Antibodies in the United States Population, 2009-2010

BACKGROUND

Polio is eliminated in the United States, with the last indigenous transmission occurring in 1979. However, global eradication of polio has not yet been completed, so importation of poliovirus into the U.S. is still possible. Specimens from the 2009-10 National Health and Nutrition Examination Survey (NHANES) were analyzed to evaluate population seroprevalence and assess overall risk from a poliovirus importation.

METHODS

We evaluated prevalence of serum antibodies to all three poliovirus types using the National Health and Nutrition Examination Survey during 2009-2010.

RESULTS

The overall seroprevalence to poliovirus was 93.9 % for type 1, 97.0 % for type 2, and 83.1 % for type 3. Seroprevalence was higher for type 2 compared to the other types (p < 0.001) and lower for type 3 compared to the other types (p < 0.001). There was a tendency for higher seroprevalence in the younger age groups, but this varied by serotype.

CONCLUSIONS

Seroprevalence was high (83.1 %-97.0 %) for all three types of poliovirus in the US population during 2009-2010. While there were observed differences by serotype with type 2 having the highest seroprevalence and type 3 having the lowest, consistent with previous observations, no large immunity gaps to poliovirus suggesting an imminent substantial population risk from a poliovirus importation were observed at a population level.

Hepatitis C Seroprevalence and Risk Factors in Adult Population of Chaharmahal and Bakhtiari Province of Iran in 2013

INTRODUCTION

Hepatitis C is the second leading viral infectious disease worldwide. In Iran, hepatitis C is the most important and prevalent reason for chronic hepatitis and liver cirrhosis in the multi transfused population.

AIM

This study was conducted to determine seroprevalence and burden of hepatitis C in Chaharmahal and Bakhtiari province and to plan for controlling it.

MATERIALS AND METHODS

For this analytical, population-based study, 3000 samples were older than 15 years old and were enrolled from urban and rural areas of Chaharmahal and Bakhtiari province, southwest Iran per cluster sampling. Written informed consent was obtained from the participants and the demographic data, transmission route and risk factors were collected after blood sample taking. Hepatitis C virus antibody (HCV Ab) and western blotting were consecutively run.

STATISTICAL ANALYSIS

Data analysis was done by SPSS 19 using descriptive statistics, and chi-square test, Fisher's exact test, and logistic regression Ap value of 0.05 was considered as the level of significance.

RESULTS

The prevalence of HCV Ab was obtained 1.4% (95% CI, 0.95-1.7) and that of positive hepatitis C by western blotting 0.9% (95% CI, 0.65-1.3). The prevalence in men (1.2%) was obtained two times higher than women. The highest prevalence was obtained in 35 to 44-year-old population (2%). The prevalence was higher in married individuals and less in higher educated. History of hospital stay, first degree relatives infected with HCV, jaundice, history of blood transfusion, tattoo, outpatient surgery, imprisonment, contact with the infected, intravenous (IV) drug abuse, and smoking had significant association with disease prevalence (p<0.05). The highest odds ratio was obtained for history of IV drug abuse (OR=38.2, 95% CI, 14.06-103.9) followed by imprisonment (OR=8.9, 95% CI, 2.97-26.6). However, by logistic regression only history of IV drug abuse was obtained as significant (p<0.05).

CONCLUSION

Hepatitis C is growing and emerging as the most prevalent chronic, viral hepatic disease, so further consideration of risk factors and routes of transmission is crucial for appropriate planning for, and preventing, treating, and controlling hepatitis C. IV drug abusers as the most important group need special consideration and surveillance in order to cut infection chain and decrease the disease incidence.

Serological survey of Bartonella spp., Borrelia burgdorferi, Brucella spp., Coxiella burnetii, Francisella tularensis, Leptospira spp., Echinococcus, Hanta-, TBE- and XMR-virus infection in employees of two forestry enterprises in North Rhine-Westphalia, Germany, 2011-2013

We initiated a survey to collect basic data on the frequency and regional distribution of various zoonoses in 722 employees of forestry enterprises in the German state of North Rhine-Westphalia (NRW) from 2011 to 2013. Exposures associated with seropositivity were identified to give insight into the possible risk factors for infection with each pathogen. 41.2% of participants were found to be seropositive for anti-Bartonella IgG, 30.6% for anti-Borrelia burgdorferi IgG, 14.2% for anti-Leptospira IgG, 6.5% for anti-Coxiella burnetii IgG, 6.0% for anti-Hantavirus IgG, 4.0% for anti-Francisella tularensis IgG, 3.4% for anti-TBE-virus IgG, 1.7% for anti-Echinococcus IgG, 0.0% for anti-Brucella IgG and anti-XMRV IgG. Participants seropositive for B. burgdorferi were 3.96 times more likely to be professional forestry workers (univariable analysis: OR 3.96; 95% CI 2.60-6.04; p<0.001); and participants seropositive for Hantavirus 3.72 times more likely (univariable analysis: OR 3.72; 95% CI 1.44-9.57; p=0.007). This study found a surprisingly high percentage of participants seropositive for anti-B. henselae IgG and for anti-F. tularensis IgG. The relatively high seroprevalence for anti-Leptospira IgG seen in this study could be related to living conditions rather than to exposure at work. No specific risk for exposure to C. burnetii and Echinococcus was identified, indicating that neither forestry workers nor office workers represent a risk population and that NRW is not a typical endemic area. Forestry workers appear to have higher risk for contact with B. burgdorferi-infected ticks and a regionally diverse risk for acquiring Hantavirus-infection. The regional epidemiology of zoonoses is without question of great importance for public health. Knowledge of the regional risk factors facilitates the development of efficient prevention strategies and the implementation of such prevention measures in a sustainable manner.

Prevalence of syphilis, human immunodeficiency virus, hepatitis B virus, and human T-lymphotropic virus infections and coinfections during prenatal screening in an urban Northeastern Brazilian population

OBJECTIVES

To evaluate prevalences of Treponema pallidum, human immunodeficiency virus (HIV), human T-lymphotropic virus (HTLV), and hepatitis B virus (HBV) infections and coinfections during prenatal screening in an urban Northeastern Brazilian population through a large dataset.

METHODS

Secondary data were obtained from the Maceió (Alagoas, Brazil) municipal prenatal screening program from June 2007 to May 2012. Dried blood serum tests from 54,813 pregnant women were examined to determine prevalences of T. pallidum, HIV, HTLV, and HBV infections and coinfections, and the seroconversion rates for syphilis and HIV infection. Socio-demographic variables associated with syphilis and HIV infection were identified.

RESULTS

The prevalences of syphilis, HIV, HTLV, and HBV infections were 2.8%, 0.3%, 0.2%, and 0.4%, respectively. Pregnant women infected with T. pallidum had a 4.62-fold greater risk of HIV coinfection, and pregnant women infected with HIV had a 5.71-fold greater risk of T. pallidum coinfection. Seroconversion for syphilis and HIV during pregnancy occurred in 0.5% and 0.06% of women, respectively. Among the women carrying HTLV, 4.2% also had an HBV infection.

CONCLUSIONS

Syphilis was twice as prevalent among pregnant women in Maceió, compared to the national average, and coinfections with syphilis/HIV and HTLV/HBV were significantly associated among these pregnant women.