Seroprevalence Of Antibodies Research Articles

Seroprevalence of Measles (Rubeola) Antibodies in Childhood Cancer Survivors.

Background: Measles is reemerging as a public health threat, raising important questions about disease vulnerability among childhood cancer survivors. This secondary analysis assessed the seroprevalence of anti-measles immunoglobulin G (IgG) antibodies as a marker of immune status in survivors of childhood cancer and associated demographic/treatment variables. Method: Participants were childhood cancer survivors who were free of active disease, having routine blood studies drawn, and could provide documentation of having received two doses of measles, mumps, and rubella vaccine before their cancer diagnosis. Patient record review documented demographic and treatment variables. Antimeasles (rubeola) IgG antibody seroprevalence was assessed by enzyme immunoassay for vaccine-specific antibodies. Results: Of 270 survivors evaluated, 110 (42%) were female, 196 (75%) were White, and 159 (61%) were leukemia/lymphoma survivors. Of these 262, 110 (42%) had negative measles seroprevalence, suggesting loss of immunity. Conclusion: Measles antibody surveillance and the need for reimmunization for survivors of childhood cancer survivors outside the transplant setting remains controversial. Our analysis indicates that a substantial proportion of survivors lose vaccine-related immunity to measles. Pediatric oncology nurses play important roles in educating cancer survivors regarding their risk of measles infection, evaluating the need for reimmunization, correcting misinformation about vaccine safety and effectiveness, and working to optimize community herd-based immunity.

Seroprevalence of Protective Antibodies Against Influenza and the Reduction of the Influenza Incidence Rate: An Annual Repeated Cross-Sectional Study From 2014 to 2019.

Seroepidemiological studies provide estimates of population-level immunity, prevalence/incidence of infections, and evaluation of vaccination programs. We assessed the seroprevalence of protective antibodies against influenza and evaluated the correlation of seroprevalence with the cumulative annual influenza incidence rate. We conducted an annual repeated cross-sectional seroepidemiological survey, during June-August, from 2014 to 2019, in Portugal. A total of 4326 sera from all age groups, sex, and regions was tested by hemagglutination inhibition assay. Seroprevalence and geometric mean titers (GMT) of protective antibodies against influenza were assessed by age group, sex, and vaccine status (65+ years old). The association between summer annual seroprevalence and the difference of influenza incidence rates between one season and the previous one was measured by Pearson correlation coefficient (r). Significant differences in seroprevalence of protective antibodies against influenza were observed in the population. Higher seroprevalence and GMT for A(H1N1)pdm09 and A(H3N2) were observed in children (5-14); influenza B seroprevalence in adults 65+ was 1.6-4.4 times than in children (0-4). Vaccinated participants (65+) showed significant higher seroprevalence/GMT for influenza. A strong negative and significant correlation was found between seroprevalence and ILI incidence rate for A(H1N1)pdm09 in children between 5 and 14 (r = -0.84; 95% CI, -0.98 to -0.07); a weak negative correlation was observed for A(H3N2) and B/Yamagata (r ≤ -0.1). The study provides new insight into the anti-influenza antibodies seroprevalence measured in summer on the ILI incidence rate in the next season and the need for adjusted preventive health care measures to prevent influenza infection and transmission.

Seroprevalence of rubella antibodies among pregnant women in Setif_Algeria

Seroprevalence of rubella antibodies among pregnant women in Setif_Algeria

Blood donation and seroprevalence of covid-19 antibodies among blood donors at central blood bank, Palestine

Blood donation and seroprevalence of covid-19 antibodies among blood donors at central blood bank, Palestine

Scenarios of future mpox outbreaks among men who have sex with men: a modelling study based on cross-sectional seroprevalence data from the Netherlands, 2022.

BackgroundFollowing the 2022-2023 mpox outbreak, crucial knowledge gaps exist regarding orthopoxvirus-specific immunity in risk groups and its impact on future outbreaks.AimWe combined cross-sectional seroprevalence studies in two cities in the Netherlands with mathematical modelling to evaluate scenarios of future mpox outbreaks among men who have sex with men (MSM).MethodsSerum samples were obtained from 1,065 MSM attending Centres for Sexual Health (CSH) in Rotterdam or Amsterdam following the peak of the Dutch mpox outbreak and the introduction of vaccination. For MSM visiting the Rotterdam CSH, sera were linked to epidemiological and vaccination data. An in-house developed ELISA was used to detect vaccinia virus (VACV)-specific IgG. These observations were combined with published data on serial interval and vaccine effectiveness to inform a stochastic transmission model that estimates the risk of future mpox outbreaks.ResultsThe seroprevalence of VACV-specific antibodies was 45.4% and 47.1% in Rotterdam and Amsterdam, respectively. Transmission modelling showed that the impact of risk group vaccination on the original outbreak was likely small. However, assuming different scenarios, the number of mpox cases in a future outbreak would be markedly reduced because of vaccination. Simultaneously, the current level of immunity alone may not prevent future outbreaks. Maintaining a short time-to-diagnosis is a key component of any strategy to prevent new outbreaks.ConclusionOur findings indicate a reduced likelihood of large future mpox outbreaks among MSM in the Netherlands under current conditions, but emphasise the importance of maintaining population immunity, diagnostic capacities and disease awareness.

Possible vertical transmission of Chikungunya virus infection detected in the cord blood samples from a birth cohort in Vietnam

BackgroundChikungunya virus (CHIKV) is an alphavirus (genus Alphavirus, family Togaviridae) that is primarily transmitted to humans by Aedes mosquitoes, and can be transmitted from mother to child. Little is known about CHIKV transmission in Vietnam, where dengue is endemic and Aedes mosquitoes are abundant. This study aimed to determine the prevalence and characteristics of vertical CHIKV infection in a birth cohort, and seroprevalence of anti-CHIKV antibodies with or without confirmation by neutralization tests among women bearing children in Vietnam. MethodsWe collected umbilical cord blood plasma samples from each newly delivered baby in Nha Trang, Central Vietnam, between July 2017 and September 2018. Samples were subjected to molecular assay (quantitative real-time RT-PCR) and serological tests (anti-CHIKV IgM capture and IgG indirect enzyme-linked immunosorbent assay, and neutralization tests). ResultsOf the 2012 tested cord blood samples from newly delivered babies, the CHIKV viral genome was detected in 6 (0.3%) samples by RT-PCR, whereas, 15 samples (0.7%) were anti-CHIKV-IgM positive. Overall, 18 (0.9%, 95% CI: 0.6–1.5) samples, including three positives for both CHIKV IgM and viral genome on RT-PCR, were regarded as vertical transmission of CHIKV infection. Of the 2012 cord blood samples, 10 (0.5%, 95% CI: 0.2–0.9) were positive for both anti-CHIKV IgM and IgG. Twenty-nine (1.4%, 95% CI: 1.0–2.1) were seropositive for anti-CHIKV IgG while 26 (1.3%, 95% CI: 0.8–1.9) of them were also positive for neutralizing antibodies, and regarded as seropositive with neutralization against CHIKV infection. ConclusionThis is the first report of a possible CHIKV maternal-neonatal infection in a birth cohort in Vietnam. The findings indicate that follow-up and a differential diagnosis of CHIKV infection in pregnant women are needed to clarify the potential for CHIKV vertical transmission and its impact in the newborn.

Seroprevalence of Measles and Rubella IgG Antibodies in Children and Pregnant Women in Iran

Background: Complete immunization against Rubella and Measles (MR) in pediatrics is achieved using 2 doses of the Measles, Mumps, and Rubella-containing vaccine (MMR) in Iran at 12 and 18 months of age, where more than 95% of children under 5 years of age are vaccinated. Antibody waning in mothers and older children, and genetic diversity in immune responses may render them susceptible to infections. Objectives: This study aimed to investigate the diversity in immunoglobulin G (IgG) antibody levels against these two viruses in pregnant women, infants younger than 2 months, children at 6, 12, and 18 months, and 5 - 6 years of age in Iran. Methods: This study was conducted on serum specimens sent to the National Reference Laboratory for Measles and Rubella in Tehran, Iran, from children under 2 months (n: 50), 6 (n: 54), 12 (n: 54), and 18 (n: 39) months, and 5 - 6 years old (n: 49), as well as women at 37 weeks of pregnancy (n: 53), from May to December 2020. Rubella and Measles-specific IgG were measured using an enzyme-linked immunosorbent assay kit. Results: Among serum samples from different provinces of Iran, the lowest positive level of Measles IgG was observed in children aged 6 and 12 months (7.41%), while the highest positive level was found in children aged 18 months (84.62%). For Rubella, the lowest IgG-positive level was seen in children aged 11 - 13 months (11.11%), while the highest positive level was observed in the 5 - 6 years old group (83.67%). Antibody levels against measles and rubella were higher in pregnant women than in children. Conclusions: Measles and Rubella antibody titers were lower in children 12 months before vaccination and reached a positive level in children aged 18 months post-vaccination. Whereas, lower Measles IgG levels in 5 - 6 years old children compared to 18 months old children may be due to waning antibodies. Pregnant women exhibited high levels of protection against these viruses (more than 80% had positive rubella IgG), as anticipated from outcomes of the national vaccination program in 2004.

Seroprevalence And Risk Factors Of Toxoplasmosis Antibodies Among Students At Jiblah University, Yemen2024: A Cross-Sectional Study

Seroprevalence And Risk Factors Of Toxoplasmosis Antibodies Among Students At Jiblah University, Yemen2024: A Cross-Sectional Study

SEROLOGICAL SURVEY OF LYME BORRELIOSIS IN THE SOUTH REGION OF KAZAKHSTAN

Lyme borreliosis (LB) is an infectious disease caused by spirochetes of the Borrelia burgdorferi sensu lato complex. Transmission occurs through the bites of hard ticks within the genus Ixodes. Cases of fever of unknown origin are recorded in southern Kazakhstan, however, the prevalence of LB in this area remains unstudied. Almaty oblast is recognized as an endemic area for LB. Ixodid tick vectors also inhabit Jambyl oblast, where antibodies to LB agent were previously detected among residents, while it is classified as non-endemic. Turkistan oblast is also considered non-endemic for LB. The purpose of this study was to investigate the seroprevalence of IgG antibodies to B. burgdorferi s.l. among apparently healthy residents of Almaty city (Almaty oblast), Taraz city (Jambyl oblast), and Shymkent city (Turkistan oblast). A total of 465 human serum samples were collected from March 2022 to September 2023. Using the ELISA method, we detected the presence of IgG antibodies to the LB agent in 5.4% of the entire study group (24/465, 95% CI: 3.3-7.6%), and specifically in 9.3% of residents of Almaty city (11/118, 95% CI: 4.7-16.1%, p=0.03), 4.5% – Taraz city (11/242, 95% CI: 2.3-8.0%) and 1.9% – Shymkent city (2/105, 95% CI: 0.2-6.7%). The results of the study confirm the seroprevalence of IgG antibodies to B. burgdorferi s.l. among the population of Almaty city and Jambyl oblast, and also reveal seropositive samples in residents of Turkistan oblast, suggesting possible infection during travel to endemic regions. It is important to continue LB surveillance in endemic and emerging regions, as well as to raise awareness of the infection among healthcare workers and the general public in non-endemic areas.

Seroprevalence of brucellosis antibodies and associated risk factors among the hospitalized patient, Aleppo, Syria: a hospital-based cross-sectional study.

Brucellosis is one of the most common infectious diseases in the world, especially in developing countries. Recent reports show that Syria is among the top ten countries where brucellosis is most prevalent. The purpose of this study is to estimate the seroprevalence of brucellosis antibodies among the hospitalized patients, in one of the largest hospitals in northern Syria. A cross-sectional study was conducted among the hospitalized patients. The authors used a questionnaire to collect sociodemographic and brucellosis-related data from the patients. The authors also collected blood samples from these patients to be screened for brucellosis antibodies using Wright Coombs Agglutination and 2-mercaptoethanol tests, during the period from November 2021 and March 2022. Among the 776 patients who were recruited in the study, the seroprevalence of brucellosis antibodies was 13.1% (n=776). The highest prevalence was among the female sex (16.7%, n=298), middle aged group 12-40 years (24.1%, n=116), and patients with history of brucellosis (30.1%, n=53). Among the positive samples, the findings of 2-mercaptoethanol tests show that (14.7%, n=102) were positive (presence of IgG Antibodies), and (75.5%, n=102) were negative. This study is the first to describe the epidemiology of brucellosis in northern Syria. It clearly shows high rates of positivity, which reflects immense challenges facing the public health sector in Syria. The best next step in light of this crisis is to raise awareness among population about brucellosis and its risk factor.

A Pilot Seroprevalence Study Suggests Silent Zika virus Transmission in Bhopal Region of Central India.

Several sporadic cases and outbreaks of Zika virus disease have been reported from different states of India. This paper explored the possibility of any ongoing transmission of Zika virus (ZIKV) in the Bhopal region of Central India, where the last outbreak of this disease was reported in 2018. We screened a group of 75 febrile patients who had already tested negative for the locally endemic causes of fever like dengue, chikungunya, enteric fever, malaria, and scrub typhus and two groups of asymptomatic healthy individuals represented by blood donors (n = 75) and antenatal mothers (n = 75). We tested blood samples of febrile patients for ZIKV RNA using real-time polymerase chain reaction (PCR), and for the healthy individuals, we determined anti-zika immunoglobulin G (IgG) antibodies using enzyme-linked immunosorbent assay. ZIKV RNA was not detected in any of the 75 samples tested by real-time PCR assay. Among the voluntary blood donors and antenatal mothers, a total of 10 (15.38%) and 5 (6.66%) individuals were found to be seropositive for anti-ZIKV IgG antibodies, respectively. The seropositive group was found to have higher age 33.06 (±10.83) years as compared to seronegative individuals 26.60 (±5.12) years (P = 0.037). This study, which is the first survey of seroprevalence of anti-Zika antibodies from India, reports an overall seropositivity rate of 10% for anti-Zika antibodies among the healthy population, suggesting an ongoing, low level, silent transmission of ZIKV in the local community.

Seroprevalence and Risk Factors Associated with Leptospirosis in High-Risk Occupational Groups in the State of Gujarat as Determined by IgM ELISA and MAT Test: A Cross-Sectional Study.

Leptospirosis is a reemerging zoonosis affecting humans and animals worldwide in tropical and subtropical countries. The study was conducted to estimate the seroprevalence of leptospirosis in high-risk occupational groups (cattle farm workers, poultry farm workers, and slaughterhouse workers) in the state of Gujarat and to determine related risk factors for leptospirosis. Using an interview-guided questionnaire, a cross-sectional study was conducted involving 123 people in high-risk occupational groups (namely, cattle farm workers, poultry farm workers, and slaughterhouse workers) from five districts of the state of Gujarat, India. The participants' serum samples were screened for antileptospiral antibodies by using Immunoglobulin G (IgG) and Immunoglobulin M (IgM) enzyme-linked immunosorbent assays (ELISAs) followed by a microscopic agglutination test (MAT). The Chi-square (χ2) test and odds ratio were calculated using IBM SPSS Statistics for Windows, version 22 (IBM Corp., Armonk, N.Y., USA) to ascertain the associated risk factors. Regarding demographic information, this study included 104 men and 19 women in high-risk occupational groups. The overall seroprevalence of antileptospiral antibodies in these high-risk workers was 46.3%. The seroprevalence was the highest among poultry farm workers (56.6%), followed by cattle farm workers (54.5%) and slaughterhouse workers (25.6%). The MAT in combination with IgM is adequate for the serological diagnosis of leptospirosis, but we have also employed IgG ELISA to understand the chronic infection in these high-risk occupational groups as exposure was both past and present. Tests were conducted for antibodies against various Leptospira serovars in the major serogroups; frequent serovars included Hurstbridge, Panama, Javanica, Tarassovi, Copenhageni, Pomona, and Weaveri, among others. The significant (P < 0.05) risk factors associated with leptospirosis in these high-risk occupations reported to be living in field areas, the presence of livestock in the neighborhood, working in slaughterhouses, drinking water from natural water resources, contact with animals such as dogs or livestock, and wounds during occupational practice. Considering the high seroprevalence of leptospirosis, high-risk occupational groups should be regularly screened for potential development of the fatal disease. Hurstbridge was found to be the most prevalent serovar in the studied population, followed by Panama, Javanica, and Tarassovi.

Utility of COVID-19 Seropositive Plasma as Convalescent Plasma: An Immune and Neutralization Antibody Seroprevalence Analysis in Blood Donors for Future Potential Pandemic Readiness.

To analyze the seroprevalence of SARS-CoV-2 IgG antibodies and neutralizing antibodies in blood donors during the second wave of the pandemic and to explore the utility of COVID-19 seropositive plasma as convalescent plasma. In this study, 696 blood donors were tested for anti-SARS-CoV-2 IgG antibodies using a chemiluminescence assay. By blinding, 271 samples were chosen randomly for testing of neutralizing antibodies by enzyme-linked immunosorbent assay (ELISA) in duplicate among the 696 blood donors tested for anti-SARS-CoV-2 IgG antibodies, irrespective of the positivity or negativity of the result of the anti-SARS-CoV-2 IgG antibodies by chemiluminescence assay.IgG antibody levels were analyzed in signal-to-cutoff (S/Co), while neutralizing antibody levels were analyzed in percentage inhibition. The seroprevalence of IgG antibodies based on the S/Co for the positive results ≥ 1.00 was 82.75%, while the seroprevalence of neutralizing antibodies based on the percentage inhibition for the positive results ≥ 30% was 89.59%. Frontline workers (FLWs) and Covishield-vaccinated individuals showed higher levels of the anti-SARS-CoV-2 IgG antibodies regarding higher S/Co. In comparison, levels of neutralization antibodies regarding percentage inhibition were higher only in FLWs.Covishield-vaccinated donors elicited a statistically higher seroprevalence of anti-SARS-CoV-2 IgG antibodies compared to the Covaxin-vaccinated, while the seroprevalence of neutralizing antibodies was not statistically different among this group. There was a positive correlation (0.762) between anti-SARS-CoV-2 IgG antibodies and neutralizing antibodies, and almost all donors'of S/Co ≥ 9.5 had neutralizing antibodies. This study showed higher seroprevalence in the blood donor population compared to published seroprevalence in India's second wave of the pandemic. In the current study, 328 donors (47.12%) of the 696 screened donors were neither vaccinated nor had previous SARS-CoV-2 infection, but many had antibodies. The seroprevalence of neutralizing antibodies (96.42%) was higher than the seroprevalence of the anti-SARS-CoV-2 IgG antibodies (85.71%) in the donors who had previous infection of COVID-19. On the other hand, vaccinated donors showed similar immune responses for neutralizing antibodies and the anti-SARS-CoV-2 IgG antibodies. Higher IgG immune reactivity in S/Co showed a good correlation with neutralizing antibodies and can be used to screen whole blood donors for convalescent plasma donations.

Histoplasma seropositivity and environmental risk factors for exposure in a general population in Upper River Region, The Gambia: A cross-sectional study

Robust surveillance of Histoplasma species is warranted in endemic regions, including investigation of community-level transmission dynamics. This cross-sectional study explored anti-Histoplasma antibody seroprevalence and risk factors for exposure in a general population in Upper River Region (URR), The Gambia.Study participants were recruited (December 2022–March 2023) by random household sampling across 12 Enumeration Areas (EAs) of URR. A questionnaire and clinical examination were performed; exploring demographic, clinical and environmental risk factors for Histoplasma exposure. One venous blood sample per participant was subject to IMMY Latex Agglutination Histoplasma test to determine presence of a recent IgM response to Histoplasma. Seropositivity risk factors were explored by multi-level, multivariable logistic regression analysis.The study population (n = 298) aged 5–83 years, demonstrated a positively skewed age distribution and comprised 55.4% females. An apparent seroprevalence of 18.8% (n = 56/298, 95% CI 14.5–23.7%) was measured using the LAT. A multivariable model demonstrated increased odds of Histoplasma seropositivity amongst female participants (OR = 2.41 95% CI 1.14–5.10); and participants reporting involvement in animal manure management (OR = 4.21 95% CI 1.38–12.90), and management of domestic animals inside the compound at night during the dry season (OR = 10.72 95% CI 2.02–56.83). Increasing age (OR = 0.96 95% CI 0.93–0.98) was associated with decreased odds of seropositivity. Clustering at EA level was responsible for 17.2% of seropositivity variance.The study indicates frequent recent Histoplasma exposure and presents plausible demographic and environmental risk factors for seropositivity. Histoplasma spp. characterisation at this human-animal-environment interface is warranted, to determine public health implications of environmental reservoirs in The Gambia.The study was supported by Wellcome Trust (206,638/Z/17/Z to CES) and a University of Liverpool-funded PhD studentship (to TRC).

Seroprevalence of antibodies against SARS-CoV-2 in the school community in Campo Grande, state of Mato Grosso do Sul, Brazil, October 2021-November 2022.

With the reopening of schools during the coronavirus disease 2019 (COVID-19) pandemic, it was imperative to understand the role of students and education professionals in the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this paper, we determined the seroprevalence of the SARS-CoV-2 anti-nucleocapsid antibodies in the school community in Campo Grande, the capital and most populous city of the state of Mato Grosso do Sul (Brazil) and evaluated its association with sex, school level, and school type. The survey was carried out in 20 public and private schools in the urban region of Campo Grande using the TR DPP® COVID-19 immunoglobulin M/immunoglobulin G (IgM/IgG) kit from the Immunobiological Technology Institute (Bio-Manguinhos, Rio de Janeiro, Brazil). Testing was carried out in three periods: from October to December 2021; from March to July 2022; and from August to November 2022. The participants were students aged 6-17 years enrolled in primary or secondary schools and professionals of different ages and roles. During the first testing period, 162 participants were seropositive for the IgM and/or IgG anti-nucleocapsid SARS-CoV-2 antibodies, with an estimated seroprevalence of 19.6% using Bayesian multilevel regression. In the second period, 251 participants were seropositive (estimated seroprevalence, 34.6%), while in the third period, 393 participants were seroconverted (estimated seroprevalence, 56.7%). In 2022, there was an increase in the seroconversion rate compared to that in 2021. The most frequently described acute manifestations in the three periods were fever, headache, sore throat, and runny nose. In terms of the demographic profile, there was no predominance of seropositivity between the sexes, although women represented approximately 70% of the study population. There were also no differences between students and school staff. The results made it possible to evaluate the extent of SARS-CoV-2 transmission in the school community through immunity developed against the virus, in addition to providing information about COVID-19 symptoms in children, adolescents, and adults.

Yellow fever neutralizing antibody seroprevalence proportion and titers in previously vaccinated adults with chronic kidney disease

Studies on yellow fever vaccine (YF) in chronic kidney disease (CKD) patients are scarce. This cross-sectional study aimed to evaluate YF neutralizing antibody seroprevalence and titers in previously vaccinated adults with CKD, on dialysis (D-CKD) or not (ND-CKD), compared to healthy persons. The micro Plaque Reduction Neutralization-Horseradish Peroxidase (μPRN-HP) test was used. Antibody titers were expressed as the reciprocal of the highest dilution that neutralized the challenge virus by 50 % (μPRN50). Seropositivity cut-off was set at ≥ 1:100. We included 153 participants: 46 ND-CKD, 50 D-CKD and 57 healthy adults. Median ages were 58.3, 55 and 52.2 years, respectively. Median time since YF vaccination was 22.3, 18.5 and 48.3 months respectively. There were no statistically significant differences in YF seroprevalence and neutralizing antibodies titers among groups: 100 % of ND-CKD; 96 % of D-CKD and 100 % of healthy participants were seropositive. Geometric mean titers (GMT) were 818.5, 683.0 and 665.5, respectively (p = 0.289).

Seroprevalence of Toxoplasma gondii Antibodies and Associated Risk Factors Among Women in Zakho City, Iraq.

Toxoplasmosis, an infectious disease caused by the obligate intracellular protozoan parasite, poses varying degrees of risk, ranging from asymptomatic cases in immunocompetent individuals to severe, life-threatening conditions in immunocompromised individuals and developing fetuses, especially when infection occurs during early pregnancy. While the disease is endemic in Iraq, there is a notable lack of precise information regarding its seroprevalence among females of childbearing age and pregnant women, along with associated risk factors in the Zakho district. This cross-sectional study aimed to address this gap by determining the prevalence of anti-Toxoplasma gondii IgG and IgM antibodies using the ELISA assay. The study involved 610 females aged 18-79 years from various residential areas within Zakho district, Iraq. The findings revealed a seroprevalence of 32.46% for anti-Toxoplasma IgG antibodies and 8.86% for IgM antibodies. Significant variations in IgG antibody seroprevalence were observed across different age groups (P=0.008), with the highest prevalence noted among those aged 46-55 years (47.73%). Conversely, IgM antibody seroprevalence, while non-significant (P>0.05), displayed the highest rate of 10.05% among ages 18-25 years. The study identified residence as a variable significantly associated with toxoplasmosis. Additionally, contact with cats, marital status, a history of abortion, and the consumption of homemade food showed significant associations with anti-Toxoplasma IgM antibodies only. These findings strongly suggest that Toxoplasma gondii is a prevalent causative agent of infection in Zakho city, Iraq. This study contributes valuable insights into the seroprevalence and associated risk factors, providing a foundation for targeted interventions and further research in this region.

Infectious Diseases Society of America Guidelines on the Diagnosis of COVID-19: Serologic Testing.

The role of serologic testing for SARS-CoV-2 has evolved during the pandemic as seroprevalence in global populations has increased. The Infectious Diseases Society of America (IDSA) convened an expert panel to perform a systematic review of the coronavirus disease 2019 (COVID-19) serology literature and construct updated best practice guidance related to SARS-CoV-2 serologic testing. This guideline is an update to the fourth in a series of rapid, frequently updated COVID-19 guidelines developed by IDSA. To develop evidence-based recommendations and identify unmet research needs pertaining to the use of anti-SARS-CoV-2 antibody tests for diagnosis, decisions related to vaccination and administration of monoclonal antibodies or convalescent plasma in immunocompromised patients, and identification of a serologic correlate of immunity. A multidisciplinary panel of infectious diseases clinicians, clinical microbiologists and experts in systematic literature reviewed, identified, and prioritized clinical questions related to the use of SARS-CoV-2 serologic tests. Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to assess the certainty of evidence and make testing recommendations. The panel recommends against serologic testing to diagnose SARS-CoV-2 infection in the first two weeks after symptom onset (strong recommendations, low certainty of evidence). Serologic testing should not be used to provide evidence of COVID-19 in symptomatic patients with a high clinical suspicion and repeatedly negative nucleic acid amplification test results (strong recommendation, very low certainty of evidence). Serologic testing may assist with the diagnosis of multisystem inflammatory syndrome in children (strong recommendation, very low certainty of evidence). To seek evidence for prior SARS-CoV-2 infection, the panel suggests testing for IgG, IgG/IgM, or total antibodies to nucleocapsid protein three to five weeks after symptom onset (conditional recommendation, low certainty of evidence). In individuals with previous SARS-CoV-2 infection or vaccination, we suggest against routine serologic testing given no demonstrated benefit to improving patient outcomes (conditional recommendation, very low certainty of evidence.) The panel acknowledges further that a negative spike antibody test may be a useful metric to identify immunocompromised patients who are candidates for immune therapy. The high seroprevalence of antibodies against SARS-CoV-2 worldwide limits the utility of detecting anti-SARS CoV-2 antibody. The certainty of available evidence supporting the use of serology for diagnosis was graded as very low to low. Future studies should use serologic assays calibrated to a common reference standard.

Seroprevalence of tetanus and pertussis antibodies among health care workers in Wuhu, China

ABSTRACT This study aimed to elucidate the seroprevalence of antibodies to tetanus and pertussis among Chinese health care workers. Blood specimens from health care workers were collected during the 2021 annual medical examination at the First People’s Hospital of Wuhu. Commercial ELISA kits were employed to quantify serum IgG antibodies against tetanus toxin (anti-TT IgG) and both IgG and IgA antibodies against pertussis toxin (anti-PT IgG, anti-PT IgA). A concentration of anti-TT IgG exceeding 0.1 IU/ml was deemed seroprotective against tetanus, while concentrations of anti-PT IgG ≥ 50 IU/ml or anti-PT IgA ≥ 15 IU/ml were indicative of a prior pertussis infection. The overall seroprotective rate for anti-TT IgG stood at 10.43% (92/882), with the highest seroprotective rate (13.91%) in the 20–29 age group, followed by the 30–39 age group (10.57%), 40–49 age group (5.80%), and 50–59 age group (5.63%). Eighteen (2.04%) of the studied subjects were positive to anti-PT IgG, and the positive rate in 20–39 age group and 40–59 age group was 1.19% (8/673) and 4.78% (10/209), respectively. Thirty (3.40%) subjects displayed anti-PT IgG levels ≥100 IU/ml and/or anti-PT IgA ≥ 15 IU/ml, suggesting a recent pertussis infection within the preceding year. Over half (503/882, 57.03%) had undetectable anti-PT IgG antibodies. The majority of health care workers in China appear susceptible to tetanus and pertussis, and a significant subset has experienced pertussis infection. The implementation of booster vaccinations against these diseases for Chinese health care workers is recommended.

Seroprevalence and molecular investigation of toxocariasis in working children and control group in Tehran, Iran

BackgroundToxocariasis, a zoonosis helminthic disease is caused in humans by Toxocara canis and Toxocara cati with worldwide distribution. In this study the seroprevalence and molecular toxocariasis were investigated in the working children and the control group in Tehran, Iran. MethodsIn total, 468 children between the ages of 7–14 years old, including 280 blood samples from working children and 188 samples from control group children were collected from Tehran. ELISA test was performed to detect IgG antibody against Toxocara canis. Molecular tests using ITS2 primer were performed to determine the status of toxocariasis infection in children. ResultsThe seroprevalence of toxocariasis was 24 (8.6%) and 10 (5.3%) in the working children and control group respectively. Seroprevalence of toxocariasis in girls 18(13.5%) was higher than boys 6(4.1%) in working children and differences was statistically significant. A significant relationship was found between contact with soil or contact with cats and dogs and the seroprevalence of toxocariasis in working children. No amplification of the target DNA was detected in plasma or whole blood samples in working children and the control group with Toxocara canisand cati primers. ConclusionThe seroprevalence of IgG antibody against Toxocara canis was higher in working children than in the control group in Tehran. The result of the present study indicated a significant difference between working children and the control group in terms of Toxocara canis antibody titer. More contact with soil in these children and contact with dogs and cats may be factors in acquiring toxocariasis in the children.