Prevalence Of IgM Research Articles

Serological study of human Cytomegalovirus spread among aborted women in Najaf Governorate and assessment of MCP-1 chemokine effect on the virus

This study aims to determine the prevalence of IgM, IgG, anti-Human cytomegalovirus (HCMV) in Najaf women and determining the level of MCP-1 chemokine concentration and its role in the immune response. This study was conducted on 65 were suffering from HCMV infection and were referred to the women's consulting clinic and maternity halls in each of the Al-Zahra teaching hospital and Al-Manathira general hospital and 15 women as a control without any miscarriage, during the period from 6 April to 12 June, and these samples were chosen within the age range is between (18 to 40) years. HCMV IgM, IgG antibody tests were performed using Enzyme-Linked Immunosorbent Assay, and the result showed that the prevalence of IgG and IgM immunoglobulins in pregnant women with miscarriages according to the statistical analysis that there is a high significantly difference with a level ≤ P 0.05 in IgG and IgM concentration within different age groups of aborted women compared to the control treatment group of women.

Prevalence and risk factors for hepatitis E virus infection in blood donors: a nationwide survey in Italy, 2017 to 2019.

BackgroundIn high-income countries, hepatitis E virus (HEV) infection is mainly a zoonosis. However, it is also transfusion-transmissible and some countries, but not Italy, have introduced HEV screening for blood donations.AimWe assessed HEV infection prevalence and risk factors in a nationwide sample of Italian blood donors.MethodsWe selected 107 blood establishments (BE) distributed in the 20 Italian regions by a stratified two-stage design and invited them to participate in the study. Donors were tested for anti-HEV IgG and IgM and HEV RNA. Sociodemographic data and risk factors were collected through a questionnaire.ResultsOverall, 60 BE from 60 provinces in 19 Italian regions joined the study. We assessed HEV markers in 7,172 blood donors, of whom 6,235 completed the questionnaire. Overall crude and adjusted anti-HEV IgG prevalences were 8.3% and 5.5%, respectively. Overall anti-HEV IgM prevalence was 0.5%, while no blood donor was HEV RNA-positive. Anti-HEV IgG prevalence varied widely among regions (range: 1.3%–27.20%) and hyperendemic prevalences (> 40%) were detected in some provinces in two regions. Older age (AOR = 1.81; 95% CI: 1.36–2.41), foreign nationality (AOR = 2.77; 95% CI: 1.06–7.24), eating raw pork liver sausages (AOR = 2.23; 95% CI: 1.55–3.20) and raw homemade sausages (AOR = 3.63; 95% CI: 2.50–5.24) were independent infection predictors.ConclusionItalian blood donors showed a low to moderate HEV seroprevalence. High levels in some regions and/or provinces were mainly attributable to eating habits. Prevention should include avoiding consumption of raw or undercooked meat and safe production of commercial pork products.

Chikungunya virus seroprevalence in asymptomatic blood donors during an outbreak in the Federal District of Brazil.

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus belonging to the Togaviridae family. The symptomatic infection is characterised by acute febrile disease which generally results in severe arthralgia and myalgia, however, most of the CHIKV infections remain asymptomatic. CHIKV RNA detection in asymptomatic volunteers may be responsible for the transfusion transmission of this infection, especially during outbreaks. There is no information for CHIKV seroprevalence among blood donors from the Federal District of Brazil. In early 2019, the Federal District of Brazil experienced a CHIKV outbreak, and this study evaluates the anti-CHIKV IgM and IgG presence in a well characterised cohort of blood donors from this region. Blood samples were collected from 450 volunteer blood donors during a CHIKV outbreak and tested for the presence of anti-CHIKV IgG and IgM antibodies using ELISA. The CHIKV seroprevalence was 0.89% (n=4/450) and anti-CHIKV IgM prevalence was 1.11% (n=5/450). The obtained results demonstrated that at least some of the blood donors have experienced CHIKV infection which can be related to a hypothetical risk of CHIKV transfusion transmission. More studies are necessary in order to examine the impact of CHIKV on blood transfusion.

SEROPREVALENCE OF HUMAN PARVOVIRUS B19 IgM AND IgG AMONG ASYMTOMATIC DONORS IN LAGOS, NIGERIA

Human parvovirus B19 is one of the emerging transfusion transmitted infections. Infection with B19 is widespread. There are limited data concerning Nigerian donors with B19 in spite of implications of such a dearth of data on health policy formation. The aim of the present study was to establish the seroprevalence of parvovirus B19 IgG and IgM antibodies among healthy blood donors in Lagos, Nigeria. Blood samples were collected between October-December 2012 from 170 asymptomatic healthy donors between ages of 20-54 years and screened for IgG and IgM antibodies using recombinant enzyme linked immunorsorbent assay kits (r-biopharm Diagnostics, Darmstadt, Germany). Net prevalence of IgM and IgG antibodies to human parvovirus B19 in this study was 65(37.6%) and 106(61.3%) respectively. A total of 39(22.9%) out of 173 blood donors screened in this research had anti- B19 antibodies (dual positivity) in their sera. Age had no statistically significant effect on anti-B19 seroprevalence among donors screened. The prevalence of parvovirus B19 among healthy donors in our study is high, and may pose adverse transfusion risk among the recipients of blood and blood products who have no detectable antibodies to parvovirus B19. This work therefore recommends routine screening for parvovirus B19 IgM antibody in blood meant for transfusion and accompanying clinical management of positive cases should be made compulsory for all donors.

Prevalence and risk factors of Hepatitis D virus antibody among asymptomatic carriers of Hepatitis B virus: a community survey.

Hepatitis D virus (HDV) can cause a chronic infection in the presence of hepatitis B surface antigen and contribute to the burden of chronic liver disease especially in regions where chronic hepatitis B virus (HBV) infection is endemic. To determine the prevalence and risk factors of HDV among asymptomatic carriers of HBsAg in Cross River State, Nigeria. This was a cross-sectional study conducted among apparently healthy adults resident in Cross River State, Nigeria. A structured questionnaire was used to collect socio-demograhic data and risk factors for HBV/HDV infection. Participants blood samples were screened for HBsAg. Samples that were HBsAg positive were further screened for anti-HDVIgM. Statistical analysis was performed using statistical package for social sciences (SPSS) version 20. A total of 90 HBsAg positive samples were assayed. The prevalence of anti-HDV IgM was 5.6% (95% CI 1.1-10.1). The HDV positive subjects were mostly females (80%), reported family size of >5 members (80%), had female circumcision (75%) and took injections from Non-certified health care practitioners (NCHCPs). None of the assessed risk factors were significantly associated with HDV infection (p >0.05). Hepatitis D virus is moderately prevalent amongst asymptomatic HBsAg carriers in Cross River State, Nigeria.

Detection of Mycobacterium Tuberculosis IgM and IgG Antibodies and Associated Risk Factors Among Apparently Healthy Undergraduate Students of a Private University in South-West Nigeria

Background: Infection with Mycobacterium tuberculosis (TB) is frequent among Nigerians. Many people are infected without realizing it (asymptomatic) and thus provide a risk of transmission to others. Not only will early treatment prevent TB complications, but it will also help to break the infection cycle in a community.
 Objective: The study was conducted to determine the prevalence of Mycobacterium tuberculosis IgM and IgG antibodies and associated risk factors among apparently healthy undergraduate Students of Babcock University, Ilishan-Remo, Ogun State. 
 Methodology: The serum samples of 100 consenting participants were collected randomly and screened for TB antibodies using Aria TB IgG/IgM Combo Rapid Antibody Test Cassette (CTK Biotech Inc. Poway, CA 92064, USA). A structured questionnaire was administered to consenting students to obtain information on their bio-data (e.g, the age, sex, study level etc.), as well as clinical information regarding their health (History of TB, history of BCG vaccination, use of anti-TB medications, alcohol consumption, smoking habits etc.). 
 Results: The outcome of this study shows that 15 (15%) out of the 100 participants screened, were positive for TB IgG antibody, while, only 1 (1%) person was positive for TB IgM antibody. There was no significant association (P>0.05) between percentage TB IgG positivity and the socio-demographic characteristics of the study participants (gender, age, study level and tribe), except for religion. The percentage of TB IgG positivity among the study participants was found to be significantly higher than of TB IgM positivity (P<0.05). None of the 15 participants who tested positive to TB IgG indicated any of the signs and symptoms (persistent cough, chest pain, nausea, fever, chills, loss of appetite, fatigue and night sweat) associated with TB), however the only person who tested positive for TB IgM indicated all, except night sweat. Identified risk factors associated with the occurrence of TB IgM include history of TB, lack of BCG vaccination, history of diabetes and physical unfitness. 
 Conclusion: The findings of this study show that asymptomatic and latent tuberculosis infection exists among the study participants, and that if left untreated, it will progress to active tuberculosis with all of its associated complications, including death. This emphasizes the importance of ongoing public health education, BCG vaccination, and periodic screening to detect asymptomatic cases in the study population in order to break the infection cycle.

Toxicity of high-molecular-weight polyethylene glycols in Sprague Dawley rats

Polyethylene glycol (PEG) is present in a variety of products. Little is known regarding the accumulation of high-molecular-weight PEGs or the long-term effects resulting from PEG accumulation in certain tissues, especially the choroid plexus. We evaluated the toxicity of high-molecular-weight PEGs administered to Sprague Dawley rats. Groups of 12 rats per sex were administered subcutaneous injections of 20, 40, or 60 kDa PEG or intravenous injections of 60 kDa PEG at 100 mg PEG/kg body weight/injection once a week for 24 weeks. A significant decrease in triglycerides occurred in the 60 kDa PEG groups. PEG treatment led to a molecular-weight-related increase in PEG in plasma and a low level of PEG in cerebrospinal fluid. PEG was excreted in urine and feces, with a molecular-weight-related decrease in the urinary excretion. A higher prevalence of anti-PEG IgM was observed in PEG groups; anti-PEG IgG was not detected. PEG treatment produced a molecular-weight-related increase in vacuolation in the spleen, lymph nodes, lungs, and ovaries/testes, without an inflammatory response. Mast cell infiltration at the application site was noted in all PEG-treated groups. These data indicate that subcutaneous and intravenous exposure to high-molecular-weight PEGs produces anti-PEG IgM antibody responses and tissue vacuolation without inflammation.

Sero – Prevalence of Rubella Virus Igm among Pregnant Women Attending Aminu Kano Teaching Hospital Kano, Nigeria

The 96 well micro-titer plate was first secured in the holder, a data sheet with sample identification was prepared, leaving one well for blank, one hundred micro- liter of negative control was added to the next 3 wells, then 100μL of positive control to the following 2 wells. One hundred micro - liter of the sample diluents was added into each of the test wells which were followed by adding 10μL of specimen into each of the wells containing sample diluents. 300 pregnant women screened for the rubella IgM antibody, a total of 12(4.0%) were positive, in the young adults category of 15-24 years 88 pregnant women were screened with 5(1.7%) testing positive. One hundred and forty four were within 25-34 age group with 4(1.3%) seropositive. Three (1.0%) 0f the 68 women in 34-44 age group were positive. The highest prevalence was found in the young adult’s category of 15-24 age groups. The research provided an evidence of relatively low prevalence and a high percentage of susceptible population which is an evidence that many in the population are susceptible to rubella virus infection. The findings of an immune response in first trimester of pregnancy indicates 90% chances of passage to the feotus with serious complications. There is need for awareness creation on rubella virus and congenital rubella syndrome with increase in disease surveillance nationwide. With high level of susceptible population coupled with no immunization policy on rubella in the country underscores the need for initiating organized routine screening and vaccination among healthcare workers, children, adolescents and women of child bearing age as well as ascertaining the potency of vaccines prior to recommendation for vaccination.
 Keywords: Sero – Prevalence, Rubella Virus, Pregnant Women

Serological Assessment of Toxoplasma Infection by ELISA method in Urban People and Livestock Farmers of Tabriz, Iran

Introduction: Toxoplasmosis is a common infection between humans and animals in the world. In its congenital form, the causative agent of the disease is transmitted through the mother’s placenta to the fetus. Acquired infection is caused by eating oocysts that the cat excretes with feces or through contaminated meat. In people who have problems with the immune system, in malignant patients, in people who do organ transplants, and in patients with AIDS, the infection may be acute and fatal. This study aimed to investigate the prevalence of IgM and IgG anti-Toxoplasma gondii antibodies in the blood serum of urban residents and livestock farmers of Tabriz, Iran, in 2021. Methods: The blood of 50 urban residents and 50 livestock farmers was taken for sampling. The patient’s arm vein was used for blood sampling. Then, the blood was kept at 37 degrees Celsius for 15 minutes and centrifuged (2000 rounds for 10 minutes). After centrifugation, the sera were carefully poured into a microtube and frozen and kept for an enzyme-linked immunosorbent assay (ELISA) test. Results: The study of the frequency distribution of toxoplasmosis by ELISA method in urban residents and livestock farmers in Tabriz and suburbs showed that out of 100 studied people, 36 cases (36%) of the total had anti-toxoplasma IgG titer higher than normal (positive). In the group of positive cases of toxoplasmosis in livestock farmers, 24 (48%) out of 50 cases had a higher-than-normal titer, which is considered positive. Further, out of the 50 urban people surveyed, 12 cases (24%) had titers higher than normal, which is considered positive. In the study of the frequency distribution of anti-toxoplasma IgM antibody by ELISA method in urban people and livestock farmers, 36 positive cases and 64 negative cases were observed out of 100 people, and15 out of 50 urban people (i.e., 30% of urban people) had IgM titer higher than normal. Moreover, an examination of 21 people out of 50 livestock farmers (42%) indicated higher than normal IgM titers. Conclusion: This study indicated that IgG and IgM antibody titers are higher in livestock farmers than in urban residents, and this suggests a relationship between occupation and toxoplasma infection. Therefore, the need is raised for extensive research at the national level to reduce the disease in livestock farmers and urban residents.

Enteric viral hepatitis in the Socialist Republic of Vietnam (Southern Vietnam)

Aim: To study the hepatitis A (HAV) and hepatitis Е (HEV) prevalence in the Southern region of Vietnam based on the frequency analysis of the antibodies to hepatitis A and E viruses detection in the local population and groups at increased risk of infection.Materials and methods. Serological markers of enteral viral hepatitis were determined in blood serum samples from adults aged 18 to 65 years of three groups: conditionally healthy individuals (n = 397), HIV-infected (n = 316), and patients with chronic viral hepatitis (n = 268). The ELISA method was used for the qualitative detection of anti-HAV IgG, anti-HAV IgM, anti-HEV IgG, anti-HEV IgM.Results. When analyzing the prevalence of anti-HAV IgG in samples obtained from conditionally healthy, HIV-infected, and patients with chronic viral hepatitis, no differences were found between the groups. The incidence of anti-HAV IgG in the general group (n = 981) was 80.1%, in the absence of anti-HAV IgM. There were no gender-age differences in the frequency of anti-HAV IgG in the examined groups. Antibodies anti-HEV IgG in the groups of conditionally healthy, patients with chronic viral hepatitis, and HIV-infected were present in the samples in 36,2%, 33,2%, and 39,8% of cases, respectively. The prevalence of anti-HEV IgM in these groups was 3,27%, 4,1%, and 3,79%, respectively. In the general group (n = 981), anti-HEV IgG was detected in 36,6% of cases, anti-HEV IgM in 3,66%, which corresponds to the prevalence of antibodies to HEV in endemic regions.Conclusion. A high incidence of enteral viral hepatitis markers was shown in residents of South Vietnam, including the groups of conditionally healthy, patients with chronic viral hepatitis, and HIV-infected. There is an obvious need for further studies of the spread extent of hepatitis A and hepatitis E in the Socialist Republic of Vietnam using currently available highly sensitive diagnostic methods, including sequencing of the virus›s nucleotide sequences.

Detection of Antibody Responses Against SARS-CoV-2 in Plasma and Saliva From Vaccinated and Infected Individuals.

Antibodies (Abs) are essential for the host immune response against SARS-CoV-2, and all the vaccines developed so far have been designed to induce Abs targeting the SARS-CoV-2 spike. Many studies have examined Ab responses in the blood from vaccinated and infected individuals. However, since SARS-CoV-2 is a respiratory virus, it is also critical to understand the mucosal Ab responses at the sites of initial virus exposure. Here, we examined plasma versus saliva Ab responses in vaccinated and convalescent patients. Although saliva levels were significantly lower, a strong correlation was observed between plasma and saliva total Ig levels against all SARS-CoV-2 antigens tested. Virus-specific IgG1 responses predominated in both saliva and plasma, while a lower prevalence of IgM and IgA1 Abs was observed in saliva. Antiviral activities of plasma Abs were also studied. Neutralization titers against the initial WA1 (D614G), B.1.1.7 (alpha) and B.1.617.2 (delta) strains were similar but lower against the B.1.351 (beta) strain. Spike-specific antibody-dependent cellular phagocytosis (ADCP) activities were also detected and the levels correlated with spike-binding Ig titers. Interestingly, while neutralization and ADCP potencies of vaccinated and convalescent groups were comparable, enhanced complement deposition to spike-specific Abs was noted in vaccinated versus convalescent groups and corresponded with higher levels of IgG1 plus IgG3 among the vaccinated individuals. Altogether, this study demonstrates the detection of Ab responses after vaccination or infection in plasma and saliva that correlate significantly, although Ig isotypic differences were noted. The induced plasma Abs displayed Fab-mediated and Fc-dependent functions with comparable neutralization and ADCP potencies, but a greater capacity to activate complement was elicited upon vaccination.

High seroprevalence of anti-DENV IgM in blood donors in an early outbreak in the Federal District of Brazil, 2019.

Dengue is endemic in Brazil, and several Brazilian cities are affected by frequent seasonal outbreaks of the disease. During the outbreaks the possibility of transfusion-transmitted dengue (TTD) is increased, mainly by the presence of asymptomatic or oligosymptomatic infections in eligible blood donors. The retrospective assessment of anti-DENV IgM and NS1 seroprevalence during a given time interval may indicate the need for measures for the previous screening of DENV infection in blood donors. In this context, we performed retrospective screening for anti-DENV IgM and NS1 in blood donors from the Federal District of Brazil during the early outbreak that occurred in 2019, the largest outbreak in recent years. In total, 450 blood donations were screened for anti-DENV IgM and DENV NS1 using commercial enzyme-linked immunosorbent assay kits (Panbio Dengue IgM Capture ELISA and Platelia Dengue NS1 Ag, respectively). Among the tested plasma samples, 16 % (72/450) presented anti-DENV IgM; no samples presented DENV NS1. Despite the apparent absence of antigenaemia in tested blood donations, the high prevalence of anti-DENV IgM highlights the importance of DENV screening in blood donors, principally during outbreak periods.

Prevalence and Determinants of Dengue Virus Immunoglobulin among Febrile Patients Attending Naval Medical Centre Victoria Island, Lagos State

Background: Dengue fever, (df) is a mosquito-borne disease caused by the dengue virus. Infection with dengue virus is a major cause of morbidity in the tropical and sub-tropical parts of the world. In about 60% of cases, it gives rise to undifferentiated fever which is clinically indistinguishable from other viral infections. Dengue fever is known to occur in Nigeria, but the magnitude of this disease remains unclear. This study was done to determine the prevalence and determinants of df immunoglobulins (Ig) among patients attending a military hospital in Lagos.Methods: Systematic random sampling was used to recruit participants. Study participants were patients presenting with febrile illness at Naval Medical Centre, Victoria Island, Lagos. A semi-structured, interviewer-administered questionnaire was used to collect data and 3 millilitres venous blood was drawn from each participant. Anti-dengue IgM and IgG was determined from whole blood using lateral flow chromatographic immunoassay in line with manufacturer’s instructions. Thick blood film was used for malaria microscopy. Epi-info version 7.2 was employed for data analysis using descriptive statistics and bivariate analysis at 5% level of significance.Results: Mean age of study participants was 30.1 ± 13.6 years and 182 (59.9%) were males. The prevalence of df IgM and IgG was 8.5% and 18.0% respectively. Malaria-dengue fever co-infection was 10.8%. Individuals with malaria were twice less likely to have df (OR: 0.46, 95%CI: 0.27 - 0.78). Military personnel and their relations were about 3 times less likely to have df (OR: 0.35, 95%CI: 0.18 - 0.66). Joint pain was significantly associated with df (OR: 1.78, 95%CI: 1.05 - 2.99).Conclusions: A significant proportion of study population had both df IgM and IgG. Screening for df should be part of routine tests amongst patients that presents with febrile illness particularly those with joint pain.

Cytomegalovirus-Associated Autoantibody against TAF9 Protein in Patients with Systemic Lupus Erythematosus

Background: Evidence indicates a causal link between cytomegalovirus (CMV) infection and the triggering of systemic lupus erythematosus (SLE). Animal studies have revealed that CMV phosphoprotein 65 (pp65) induces autoantibodies against nuclear materials and causes the autoantibody attack of glomeruli. IgG eluted from the glomeruli of CMVpp65-peptide-immunized mice exhibited cross-reactivity against dsDNA and TATA-box-binding protein associated factor 9 (TAF9). Whether the elevation of anti-TAF9 IgG is associated with anti-CMV reactivity in human lupus remains unclear. Methods: The sera from patients with rheumatic diseases, including ankylosing spondylitis (AS), gout, rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and Sjögren syndrome (SS) were examined using ELISA for antibodies of CMV, CMVpp65, and TAF9. Results: In total, 83.8% of the rheumatic patients had acquired CMV infections. The SLE patients had a high prevalence of anti-CMV IgM. The highest seropositivity rates for anti-HCMVpp65 and anti-TAF9 IgG were observed in the SLE patients. Purified anti-CMVpp65 IgG from CMVpp65/TAF9 dual-positive SLE sera reacted to both TAF9 and dsDNA. An increased prevalence of proteinuria and low hemoglobin levels were found in CMV IgG- and CMVpp65 IgG-positive SLE patients. Conclusions: This observation suggests that immunity to CMVpp65 is associated with cross-reactivity with TAF9 and dsDNA and that it is involved in the development of clinical manifestations in SLE.

Anti-SARS-COV-2 antibodies Amongst Asymptomatic Healthcare Workers and students of Tertiary Care hospital and Medical School in Pakistan

Introduction: Coronavirus emerged as a pandemic in 2019 with the SARS COV 2 virus infecting people worldwide. Although PCR successfully detected symptomatic patients, asymptomatic patients remained undetected due to limitation of resources. The objective of the study was to determine the prevalence of IgM and IgG antibodies in the faculty, staff, and MBBS students in Medical school and tertiary care hospital, Pakistan.
 Material and Methods: A cross-sectional study was conducted on 500 asymptomatic healthy subjects, from September to December 2020 in Biochemistry department Shalamar Medical and Dental College (SMDC). Rapid antibody test was used to determine the presence of IgM and IgG antibodies in the subjects. Those found IgM positive were validated by COVID 19 detection by Polymerase Chain Reaction.
 Results: Anti-SARS-COV 2 antibodies was observed in 19.6 % of 500 asymptomatic subjects. Significant reactive cases were identified in hospital staff (27.5%) compared to hospital faculty (23.4%), medical students (21.4%), college faculty (6.12%) followed by college staff (3.06%). Significant reactive cases (47.9%) were identified in middle age group i.e. between 31 to 45 years. IgG was more prevalent than IgM and 2% of the subjects showed coagulation disorders who were both IgG and IgM positive.
 Conclusion: Prevalence of 19.6% of Anti-SARS-COV 2 antibodies was observed in asymptomatic subjects. Prevalence was more in males, people in the middle age group i.e. 31 to 45 years and in hospital staff and faculty.
 Recommendations: Based on the study it is recommended that Rapid COVID 19- SRAC-2 antibody test, which is cost effective and rapid method may be used to detect the COVID 19 in developing countries with limited resources.

Humoral and cellular immune response to Plasmodium vivax VIR recombinant and synthetic antigens in individuals naturally exposed to P. vivax in the Republic of Korea

BackgroundPlasmodium vivax proteins with variant interspersed repeats (VIR) are the key proteins used by the parasite to escape from the host immune system through the creation of antigenic variations. However, few studies have been done to elucidate their role as targets of immunity. Thus, this study evaluated the naturally-acquired immune response against VIR proteins in vivax malaria-infected individuals in the Republic of Korea (ROK).MethodsSeven recombinant VIR proteins and two synthetic peptides previously studied in other countries that elicited a robust immune response were used to investigate the antibody and cellular immune response in 681 P. vivax-infected people in ROK. The expression of IgM, IgG, and IgG subclasses against each VIR antigen or against PvMSP1-19 was analysed by ELISA. PvMSP1-19, known as a promising vaccine candidate of P. vivax, was used as the positive control for immune response assessment. Furthermore, the cellular immune response to VIR antigens was evaluated by in vitro proliferative assay, cellular activation assay, and cytokine detection in mononuclear cells of the P. vivax-infected population.ResultsIgM or IgG were detected in 52.4% of the population. Among all the VIR antigens, VIR25 elicited the highest humoral immune response in the whole population with IgG and IgM prevalence of 27.8% and 29.2%, respectively, while PvMSP1-19 elicited even higher prevalence (92%) of IgG in the population. As for the cellular immune response, VIR-C2, PvLP2, and PvMSP1-19 induced high cell activation and secretion of IL-2, IL-6, IL-10, and G-CSF in mononuclear cells from the P. vivax-infected population, comparable with results from PvMSP1-19. However, no significant proliferation response to these antigens was observed between the malaria-infected and healthy groups.ConclusionModerate natural acquisition of antibody and cellular responses in P. vivax-infected Korean malaria patients presented here are similar to that in other countries. It is interesting that the immune response to VIR antigens is conserved among malaria parasites in different countries, considering that VIR genes are highly polymorphic. This thus warrants further studies to elucidate molecular mechanisms by which human elicit immune response to the malaria parasite VIR antigens.

Estimated Prevalence of SARS-CoV-2 Antibodies in the Texas Pediatric Population, 2021

Background: The extent of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children and adolescents at a population level in 2021 remains unclear. Children and adolescents have been considered to play an important role in transmission regardless of presence of symptoms. The objective of this study was to estimate the prevalence of SARS-CoV-2 antibody status in children ages 5-to-19 years in a sample from the State of Texas in the presence and absence of symptoms.Methods: The TX CARES (Texas Coronavirus Antibody Response Survey) is an ongoing prospective population-based sample from the Texas general population (~29·8 million) that commenced in October 2020. For the current analysis, volunteers ages 5-to-19 years were recruited throughout the state from large pediatric healthcare systems, Federally Qualified Healthcare Centers, urban and rural pediatric and family medicine practices, health insurance providers, and a social media campaign. SARS-CoV-2 antibody status measured via the Roche Elecsys® Anti-SARS-CoV-2 Immunoassay. Prevalence of IgM, IgA, or IgG antibodies were adjusted using sampling weights and post-stratification of age and sex. We report here findings from January 1-June 1, 2021.Findings: This analysis that included 503 children ages 5-to-19 years showed 38·7% (95% CI, 34·5-43·1) of the sample was SARS-CoV-2 antibody positive in fully adjusted estimates. A total of 30·1% (95% CI, 29·4-31·5) of adults (N=6992) in the sample were antibody positive. Over half (55·8%) of those with positive antibody status were reportedly asymptomatic. Headache (25·4%), congestion/runny nose (20·8%), and fatigue (20·3%) and were the most frequently reported symptoms among those with a positive antibody result. The odds of having a positive antibody status was 37% higher in 15-to-19 year olds versus adults (OR 1·37, 95% CI, 1·03-1·83). Interpretation: These results highlight that a majority of the pediatric population remains immunologically naive to SARS-CoV-2, emphasizing the important role vaccines may play in reaching whole population herd immunity.Funding: Texas Department of State Health Services.Declaration of Interest: We declare no competing interests.Ethical Approval: All protocols were reviewed and approved by the University of Texas Health Science Center at Houston Institutional Review Board (IRB), but also deemed public health practice by the Texas Department of State Health Services IRB.

Serologic response to SARS-CoV-2 in an African population

Official case counts suggest Africa has not seen the expected burden of COVID-19 as predicted by international health agencies, and the proportion of asymptomatic patients, disease severity, and mortality burden differ significantly in Africa from what has been observed elsewhere. Testing for SARS-CoV-2 was extremely limited early in the pandemic and likely led to under-reporting of cases leaving important gaps in our understanding of transmission and disease characteristics in the African context. SARS-CoV-2 antibody prevalence and serologic response data could help quantify the burden of COVID-19 disease in Africa to address this knowledge gap and guide future outbreak response, adapted to the local context. However, such data are widely lacking in Africa. We conducted a cross-sectional seroprevalence survey among 1,192 individuals seeking COVID-19 screening and testing in central Cameroon using the Innovita antibody-based rapid diagnostic. Overall immunoglobulin prevalence was 32%, IgM prevalence was 20%, and IgG prevalence was 24%. IgM positivity gradually increased, peaking around symptom day 20. IgG positivity was similar, gradually increasing over the first 10 days of symptoms, then increasing rapidly to 30 days and beyond. These findings highlight the importance of diagnostic testing and asymptomatic SARS-CoV-2 transmission in Cameroon, which likely resulted in artificially low case counts. Rapid antibody tests are a useful diagnostic modality for seroprevalence surveys and infection diagnosis starting 5-7 days after symptom onset. These results represent the first step towards better understanding the SARS-CoV-2 immunological response in African populations.

Evaluation of factors influencing tick bites and tick-borne infections: a longitudinal study

BackgroundVarious tick-borne infections like borreliosis and rickettsiosis pose a health risk to humans in many parts of the world. We investigated seroprevalence of and seroconversion to Borrelia burgdorferi and Rickettsia spp. and relation to tick-bites, weather and clinical manifestations in Denmark.MethodsBlood donors were enrolled at the Hospital of Southern Jutland in June–July with follow-up November–February of 2018 and 2019. Blood samples were collected, and a questionnaire regarding tick bites, potential exposures and symptoms was completed at each visit. Samples were tested for presence of IgM and IgG antibodies directed against B. burgdorferi and Rickettsia spp. using R. helvetica and R. felis as antigens. Data were examined for correlation between tick bites, serological results, potential exposures and symptoms.ResultsTwo-hundred and fourteen (93 follow-ups) and 130 (38 follow-ups) blood donors were included in 2018 and 2019, respectively. The total borrelia seroconversion rate was 6.3% (CI 2.1–10.5), while the prevalence of IgM and IgG antibodies was 7.8% (CI 4.9–10.6) and 6.7% (CI 4–9.3), respectively. Seroconversion to Rickettsia spp. was detected in one participant. Tick bites and seroconversion were not significantly associated with the reported unspecific symptoms, but unspecific symptoms were common in the study population. There was no significant difference in number of tick bites or seroconversion/prevalence between seasons with highly alternating weather.ConclusionsResults suggest that weather conditions in an individual year have a limited impact. Anti-Borrelia-antibodies do not seem to persist in serum for several years. Rickettsiosis is of limited concern in Denmark.Graphical

Seroprevalence of COVID-19 IgM and IgG antibodies among asymptomatic individuals in Khartoum State-2020

Background: Seroprevalence detection of antibodies to severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) in apparent healthy individuals will be critical for the public health response to the coronavirus disease 2019 pandemic. The aim of this study was to investigate the prevalence of IgM and IgG to covid-19 in Khartoum State. Patients and methods: A cross-sectional retrospective laboratory-based investigation was conducted in Khartoum State 2020. Apparent healthy individuals without obvious respiratory conditions, and in order to obtain a travel license were exempted; however individuals who fulfilled the participation requirements were allowed to participate. After informed consent and fitting eligibility qualifications, a blood sample was taken from each respondent and used to identify SARS-CoV-2 IgM and IgG antibody tests in COVID-19 suspected informants using a snibe system model Maglumi 800. The Statistical Package for Social Sciences (SPSS) version 23 was used for statistical analysis in form of frequencies. Results: In the state of Khartoum, a total of 1000 samples were collected from participants to determine seroprevalence of covid-19; of these, 224 were reactive and 776 were nonreactive. There were 158 reactive IgG and 66 reactive IgM within that reactive covid-19 patient. Conclusion: There was a high prevalence of SARS-CoV-2 antibodies among asymptomatic respondents in Khartoum state.