scholarly journals An age-stratified serosurvey against purified Salmonella enterica serovar Typhi antigens in the Lao People´s Democratic Republic

2021 ◽  
Vol 15 (12) ◽  
pp. e0010017
Author(s):  
Lisa Hefele ◽  
Antony P. Black ◽  
Trinh Van Tan ◽  
Nguyen Tri Minh ◽  
Nguyen Duc Hoang ◽  
...  
Keyword(s):  
Typhoid Fever ◽  
Democratic Republic ◽  
Linear Trend ◽  
Lao Pdr ◽  
Population Based ◽  
Antibody Concentration ◽  
Protein Antigens ◽  
Serum Samples ◽  
Igg Antibody ◽  
Antibody Titers

The epidemiology of typhoid fever in Lao People`s Democratic Republic is poorly defined. Estimating the burden of typhoid fever in endemic countries is complex due to the cost and limitations of population-based surveillance; serological approaches may be a more cost-effective alternative. ELISAs were performed on 937 serum samples (317 children and 620 adults) from across Lao PDR to measure IgG antibody titers against Vi polysaccharide and the experimental protein antigens, CdtB and HlyE. We measured the significance of the differences between antibody titers in adults and children and fitted models to assess the relationship between age and antibody titers. The median IgG titres of both anti-HylE and CdtB were significantly higher in children compared to adults (anti-HylE; 351.7 ELISA Units (EU) vs 198.1 EU, respectively; p<0.0001 and anti-CdtB; 52.6 vs 12.9 EU; p<0.0001). Conversely, the median anti-Vi IgG titer was significantly higher in adults than children (11.3 vs 3.0 U/ml; p<0.0001). A non-linear trend line fitted to the anti-CdtB and anti-HlyE IgG data identified a peak in antibody concentration in children <5 years of age. We identified elevated titers of anti-HlyE and anti-CdtB IgG in the serum of children residing in Lao PDR in comparison to adults. These antigens are associated with seroconversion after typhoid fever and may be a superior measure of disease burden than anti-Vi IgG. This approach is scalable and may be developed to assess the burden of typhoid fever in countries where the disease may be endemic, and evidence is required for the introduction of typhoid vaccines.

scholarly journals Validation of a new automated chemiluminescent anti-SARS-CoV-2 IgM and IgG antibody assay system detecting both N and S proteins in Japan

2020 ◽  
Author(s):  
RIn Yokoyama ◽  
Makoto Kurano ◽  
Yoshifumi Morita ◽  
Takuya Shimura ◽  
Yuki Nakano ◽  
...  
Keyword(s):  
Measurement System ◽  
False Positive ◽  
Laboratory Testing ◽  
Antibody Test ◽  
Measurement Range ◽  
Antibody Assay ◽  
Serum Samples ◽  
Igg Antibody ◽  
Antibody Titers ◽  
Pcr Test

PCR methods are presently the standard for the diagnosis of Coronavirus disease 2019 (COVID-19), but additional methodologies are needed to complement PCR methods, which have some limitations. Here, we validated and investigated the usefulness of measuring serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the iFlash3000 CLIA analyzer. We measured IgM and IgG titers against SARS-CoV-2 in sera collected from 26 PCR-positive COVID-19 patients, 53 COVID-19-suspected but PCR-negative patients, and 20 and 100 randomly selected non-COVID-19 patients who visited our hospital in 2020 and 2017, respectively. The within-day and between-day precisions were regarded as good, since the coefficient variations were below 5%. Linearity was also considered good between 0.6 AU/mL and 112.7 AU/mL for SARS-CoV-2 IgM and between 3.2 AU/mL and 55.3 AU/mL for SARS-CoV-2 IgG, while the linearity curves plateaued above the upper measurement range. We also confirmed that the seroconversion and no-antibody titers were over the cutoff values in all 100 serum samples collected in 2017. These results indicate that this measurement system successfully detects SARS-CoV-2 IgM/IgG. We observed four false-positive cases in the IgM assay and no false-positive cases in the IgG assay when 111 serum samples known to contain autoantibodies were evaluated. The concordance rates of the antibody test with the PCR test were 98.1% for SARS-CoV-2 IgM and 100% for IgG among PCR-negative cases and 30.8% for SARS-CoV-2 IgM and 73.1% for SARS-CoV-2 IgG among PCR-positive cases. In conclusion, the performance of this measurement system is sufficient for use in laboratory testing.

scholarly journals Frequency of antibodies and risk factors associated with Toxoplasma gondii infection in backyard pig production in the city of Mossoró, state of Rio Grande do Norte, Brazil

2019 ◽  
Vol 28 (3) ◽  
pp. 508-513 ◽  
Author(s):  
Isabela Maria Campanelli dos Santos ◽  
Alexandro Iris Leite ◽  
Maria Eduarda Chiaradia Furquim ◽  
Diego Carlos de Souza Zanatto ◽  
Simone de Jesus Fernandes ◽  
...  
Keyword(s):  
Risk Factors ◽  
Rio Grande ◽  
Female Gender ◽  
Immunofluorescence Assay ◽  
P Value ◽  
Serum Samples ◽  
Igg Antibody ◽  
Source Of Infection ◽  
Antibody Titers ◽  
Toxoplasma Gondii Infection

Abstract Toxoplasmosis is an important zoonosis for pregnant women and immunosuppressed people. The pig population also becomes infected by this pathogen, and undercooked or raw meat is an important source of infection for humans. The aims of the present study were to evaluate the rate of exposure of pigs to T. gondii in the municipality of Mossoró, Rio Grande do Norte and seek to identify associations with possible risk factors. Blood samples were collected from 412 pigs and were analyzed using the immunofluorescence assay. Among these 412 serum samples, 40.7% were seropositive for T. gondii. The IgG antibody titers were 64 (56 specimens), 128 (32), 256 (37), 512 (23), 1024 (14), 2048 (5) and 4046 (1). Seropositivity for T. gondii was found to be related (p-value < 0.05) to the following factors: female gender, semi-confined rearing system, use of well water, dewormed animals, presence of cats, goats, sheep, mice and vultures on the farm and carcasses left on the ground. In contrast, seropositivity was not related (p-value < 0.05) to the age of the pigs, type of facility or feeding with human food remains. Preventive measures need to be adopted on the farms studied here, with the aim of decreasing the animals’ intake of sporulated oocysts.

scholarly journals Anti-S. typhi Vi IgG levels in children with and without typhoid vaccinations

2014 ◽  
Vol 54 (5) ◽  
pp. 284
Author(s):  
Sriandayani Sriandayani ◽  
Tonny H. Rampengan ◽  
Hesti Lestari ◽  
Novie Rampengan
Keyword(s):  
Typhoid Fever ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Igg Antibody ◽  
Protective Antibody ◽  
Significant Difference ◽  
Antibody Titers ◽  
The Mean ◽  
And Gender ◽  
Antibody Levels

Background Typhoid fever is endemic to Indonesia, with an annual incidence of 13/10,000 people. Vaccination has been shown to be an effective method to prevent typhoid fever. Of several vaccine types, the polysaccharide Vi vaccine is the most commonly used typhoid vaccine in developing countries. Results of previous studies remain inconclusive on the necessity of revaccination every 3 years.Objective To compare the mean serum anrioody titers of anti-S. typhi Vi IgG and the proportion of children with protective antibody levels between children with and without typhoid Vi vaccination.Methods We conducted a cross-secrional study at Tuminring District, 11anado from June to September 2012. Data was analyzed using independent T-test and Fisher's test. Serum anti-S. typhi Vi IgG levels were measured by enzyme-linked immunosorbent assay (ELISA) method.Results Seventy-six subjects were divided into two groups: 38 children who had received the typhoid Vi vaccination more than 3 years prior to this study and 38 children who never had typhoid vaccinations as a control group. No statistically significant difference in age and gender was found between the two groups. The mean serum anti-Vi IgG level was 0.55 ug/mL (SD 0.58; 95%CI 0.36 to 0.74) in the vaccinated group, significantly higher than that of the control group [0.31 ug/mL (SD 0.12); 950/£1 0.17 to 0.44; P􀂥0.0381. The proportion of children with protective antiNi antioody level was higher in the vaccinated group (23.7%) than in the control group  (10.5%), howevet; this difference was not statistically significant (P=0.128).Conclusion The mean serum anti-S. typhi Vi IgG antibody level in children who had been vaccinated more than 3 years prior to the study is higher than in children who had never received typhoid vaccinations. Nevertheless, the mean antibody titers are generally non-protective in ooth groups. Also, the proportion of children with protective antibody levels is not significantly different between the two groups.

scholarly journals Socioeconomic correlates of antibody levels to enteric pathogens among Israeli adolescents

2006 ◽  
Vol 135 (1) ◽  
pp. 118-125 ◽  
Author(s):  
T. HASIN ◽  
R. DAGAN ◽  
G. BOUTBOUL ◽  
E. DERAZNE ◽  
O. ATIAS ◽  
...  
Keyword(s):  
Socioeconomic Status ◽  
Low Socioeconomic Status ◽  
Linear Trend ◽  
Oral Route ◽  
Serum Antibodies ◽  
Serum Samples ◽  
Igg Antibody ◽  
Significant Linear Trend ◽  
E Coli ◽  
Antibody Levels

We examined the association between socioeconomic status and the level of serum antibodies to selected faeco-orally transmitted pathogens among Israeli adolescents. Random samples of eighty volunteers aged 12–15 years from high (HSL), medium (MSL) and low (LSL) standard of living towns were included in the study. Serum samples were examined by radioimmunoassay for HAV and by in-house-developed ELISA systems for IgA and IgG antibody levels against Shigella sonnei, S. flexneri, E. coli O157[ratio ]H7 lipopolysacchride and Cryptosporidium parvum antigens. Seropositivity to HAV was highest (98·8%) in the LSL towns and lowest (25%) in the HSL towns, showing a statistically significant linear trend. Antibody levels to the other enteropathogens had gender variation, with higher titres in females. Significantly lower titres in the HSL towns were found for: IgA anti-S. sonnei in females (P<0·001); IgG anti-S. sonnei in females (P=0·024) and males (P=0·033); IgG anti-S. flexneri in females (P=0·016). Inverse linear association with socioeconomic status was found for IgA anti-C. parvum in females (P<0·001); IgA anti-E. coli O157[ratio ]H7 in females (P<0·001) and males (P=0·024). A statistically significant association between HAV seropositivity and higher titres of IgA anti-S. sonnei and E. coli O157[ratio ]H7 was shown. In conclusion, exposure to enteropathogens transmitted via the faecal–oral route in communities of lower socioeconomic status is reflected in a higher prevalence of lifelong lasting antibodies to HAV, and higher levels of antibodies to bacterial and protozoan enteropathogens. Among females, the levels of specific serum antibodies are higher and more strongly associated with low socioeconomic status.

scholarly journals Validation of a new automated chemiluminescent anti-SARS-CoV-2 IgM and IgG antibody assay system detecting both N and S proteins in Japan

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247711
Author(s):  
Rin Yokoyama ◽  
Makoto Kurano ◽  
Yoshifumi Morita ◽  
Takuya Shimura ◽  
Yuki Nakano ◽  
...  
Keyword(s):  
False Positive ◽  
Antibody Test ◽  
Measurement Range ◽  
Antibody Assay ◽  
Serum Samples ◽  
Igg Antibody ◽  
Automated Method ◽  
Antibody Titers ◽  
Pcr Test ◽  
S Proteins

PCR methods are presently the standard for the diagnosis of Coronavirus disease 2019 (COVID-19), but additional methodologies are needed to complement PCR methods, which have some limitations. Here, we validated and investigated the usefulness of measuring serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the iFlash3000 CLIA analyzer. We measured IgM and IgG titers against SARS-CoV-2 in sera collected from 26 PCR-positive COVID-19 patients, 53 COVID-19-suspected but PCR-negative patients, and 20 and 100 randomly selected non-COVID-19 patients who visited our hospital in 2020 and 2017, respectively. The repeatability and within-laboratory precision were obviously good in validations, following to the CLSI document EP15-A3. Linearity was also considered good between 0.6 AU/mL and 112.7 AU/mL for SARS-CoV-2 IgM and between 3.2 AU/mL and 55.3 AU/mL for SARS-CoV-2 IgG, while the linearity curves plateaued above the upper measurement range. We also confirmed that the seroconversion and no-antibody titers were over the cutoff values in all 100 serum samples collected in 2017. These results indicate that this measurement system successfully detects SARS-CoV-2 IgM/IgG. We observed four false-positive cases in the IgM assay and no false-positive cases in the IgG assay when 111 serum samples known to contain autoantibodies were evaluated. The concordance rates of the antibody test with the PCR test were 98.1% for SARS-CoV-2 IgM and 100% for IgG among PCR-negative cases and 30.8% for SARS-CoV-2 IgM and 73.1% for SARS-CoV-2 IgG among PCR-positive cases. In conclusion, the performance of this new automated method for detecting antibody against both N and S proteins of SARS-CoV-2 is sufficient for use in laboratory testing.

scholarly journals Seroprevalence of Toxoplasma gondii infection in cats from Curitiba, Paraná, Brazil

2011 ◽  
Vol 20 (3) ◽  
pp. 256-258 ◽  
Author(s):  
Marúcia de Andrade Cruz ◽  
Leila Sabrina Ullmann ◽  
Patrícia Yukiko Montaño ◽  
Juliano Leônidas Hoffmann ◽  
Helio Langoni ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Dietary Habits ◽  
Immunofluorescence Assay ◽  
Serum Samples ◽  
Igg Antibody ◽  
Veterinary Clinic ◽  
Warm Blood ◽  
Potential Risk Factors ◽  
Antibody Titers ◽  
Toxoplasma Gondii Infection

Toxoplasmosis is a worldwide zoonosis caused by the protozoa Toxoplasma gondii which infects all warm-blood vertebrates. This study aimed to assess the seroprevalence of anti-Toxoplasma gondii antibodies in a population of domestic cats seen at a major cat-only veterinary clinic in Curitiba, Paraná State, Southern Brazil. Serum samples were processed by indirect immunofluorescence assay (IIFA) for the detection of IgG. Antibody titers were found in 16.3% (46/282) of sera analyzed, with titers to T. gondii of 16 in eight cats, 64 in 23 cats, 256 in 14 cats and 1024 in one cat. Statistical differences were not found regarding the association with age, gender and different areas of the city (p > 0.05). No significant differences were found in any variable when comparing seropositivity with potential risk factors. The seroprevalence was relatively lower when compared to other Brazilian regions, probably due to the fact that the cats studied were owned, domiciled with restricted dietary habits based on processed foods, restricted access to the street and no prey access. In conclusion, low feline toxoplasmosis seroprevalence may be associated to owned cats due to adequate dietary care and restricted outdoor access, as well as low local environmental exposure.

scholarly journals Association of the Serum Levels of the Nucleocapsid Antigen of SARS-CoV-2 With the Diagnosis, Disease Severity, and Antibody Titers in Patients With COVID-19: A Retrospective Cross-Sectional Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Rin Yokoyama ◽  
Makoto Kurano ◽  
Yuki Nakano ◽  
Yoshifumi Morita ◽  
Hiroko Ohmiya ◽  
...  
Keyword(s):  
Clinical Significance ◽  
Serum Levels ◽  
Significant Negative Correlation ◽  
Cross Sectional Study ◽  
Characteristic Analysis ◽  
Serum Samples ◽  
Igg Antibody ◽  
Cross Sectional ◽  
Mild Disease ◽  
Antibody Titers

Background: Several types of laboratory tests for COVID-19 have been established to date; however, the clinical significance of the serum SARS-CoV-2 nucleocapsid (N) antigen levels remains to be fully elucidated. In the present study, we attempted to elucidate the usefulness and clinical significance of the serum N antigen levels.Methods: We measured the serum N antigen levels in 391 serum samples collected from symptomatic patients with a confirmed diagnosis of COVID-19 and 96 serum samples collected from patients with non-COVID-19, using a fully automated chemiluminescence immunoassay analyzer.Results: Receiver operating characteristic analysis identified the optimal cutoff value of the serum N antigen level (cutoff index, based on Youden’s index) as 0.255, which yielded a sensitivity and specificity for the diagnosis of COVID-19 of 91.0 and 81.3%, respectively. The serum N antigen levels were significantly higher in the patient groups with moderate and severe COVID-19 than with mild disease. Moreover, a significant negative correlation was observed between the serum N antigen levels and the SARS-CoV-2 IgG antibody titers, especially in patients with severe COVID-19.Conclusion: Serum N antigen testing might be useful both for the diagnosis of COVID-19 and for obtaining a better understanding of the clinical features of the disease.

scholarly journals A survey of vaccine-induced measles IgG antibody titer and the verification of changes in temporal differences of measles vaccination in young adults

2019 ◽  
Author(s):  
Hiraku Sasaki ◽  
Tomoko Fukunaga ◽  
Ai Asano ◽  
Yoshio Suzuki ◽  
Yuko Nakanishi ◽  
...  
Keyword(s):  
Young Adult ◽  
Antibody Titer ◽  
Measles Virus ◽  
Serum Samples ◽  
Igg Antibody ◽  
Adult Participants ◽  
Significant Difference ◽  
Antibody Titers ◽  
Measles Vaccination ◽  
Specific Igg

AbstractIn Japan, sporadic measles cases increased rapidly in 2019 compared to that in past 6 years. To clarify the persistence of immunity against measles in young adult, this study explored the prevalence of IgG antibody titer against measles virus in 18-to 24-year-old young adult participants. Measles-specific IgG antibody titers determined by enzyme immunoassay in serum samples collected from 506 participants between 18 to 24 years were assessed through statistical analyses. Multiple regression analysis revealed that the distribution of measles IgG antibody titers was significantly correlated with medical history (P < 0.05), while there was no significant difference among the number of vaccinations related to measles IgG titers. Further, measles IgG titers were significantly different, which was determined by the temporal change that elapsed period after last vaccination (P < 0.05). These results indicate that periodic vaccination against measles is required for young and older adults to prevent even sporadic measles infection.

Circulating Antibodies to Cardiac Protein—Acetaldehyde Adducts in Alcoholic Heart Muscle Disease

1995 ◽  
Vol 88 (3) ◽  
pp. 263-268 ◽  
Author(s):  
A. A. Harcombe ◽  
L. Ramsay ◽  
J. G. Kenna ◽  
J. Koskinas ◽  
H. J. F. Why ◽  
...  
Keyword(s):  
Heart Disease ◽  
Heart Muscle ◽  
Muscle Disease ◽  
Protein Antigens ◽  
Serum Samples ◽  
Igg Antibody ◽  
Western Immunoblotting ◽  
Molecular Sizes ◽  
Circulating Antibodies ◽  
Alcoholic Heart Muscle Disease

1. Serum samples from patients with alcoholic heart muscle disease and from control subjects with and without heart disease who did not drink to excess were screened by Western immunoblotting for antibodies to acetaldehyde-modified cardiac cytosolic proteins. 2. Two of the 64 control samples (from subjects with and without heart disease who were not drinking and from subjects with alcoholic liver disease) had detectable (IgG) antibody to acetaldehyde-modified cardiac proteins. 3. By contrast, 7 of 21 (33%) patients with alcoholic heart muscle disease had antibodies against cyanoborohydride-stabilized, acetaldehyde-modified human cardiac cytosolic protein antigens (P < 0.001). 4. Antibodies were of IgG class in six patients and IgA class in five. The molecular sizes of the protein antigens observed ranged from 58 to 120 kDa. 5. These results suggest that a proportion of patients with alcoholic heart muscle disease develop immunogenic cardiac protein—acetaldehyde adducts. The presence of antibodies to these adducts may be a marker for the diagnosis of this heart disease, or possibly for its pathogenesis.

scholarly journals Longitudinal Analysis of Tetanus- and Influenza-Specific IgG Antibodies in Myeloma Patients

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Sebastian Kobold ◽  
Tim Luetkens ◽  
Britta Marlen Bartels ◽  
Yanran Cao ◽  
York Hildebrandt ◽  
...  
Keyword(s):  
Longitudinal Analysis ◽  
Clinical Status ◽  
Cell Mediated Immunity ◽  
Serum Samples ◽  
Igg Antibody ◽  
Specific Antibodies ◽  
Time Period ◽  
Healthy Donors ◽  
Antibody Titers ◽  
Specific Igg

Background. Multiple myeloma (MM) and its therapies may induce a severely compromised humoral immunity. We have performed a longitudinal analysis of IgG-antibody responses against influenza virus (FLU) and tetanus toxoid (TT) as surrogate markers for the B cell-mediated immunity in MM patients.Methods. 1094 serum samples of 190 MM patients and samples from 100 healthy donors were analyzed by ELISA for FLU- and TT-specific antibodies.Results. MM patients evidenced lower levels of FLU- and TT-specific antibodies than healthy controls (P<0.001). Immunoreactivity decreased with progressing disease and worsening clinical status. Levels of FLU- and TT-specific antibodies increased shortly (0-6 months) after alloSCT (P<0.001), a time-period during which intravenous immunoglobulin (IVIG) is routinely applied. Thereafter, antibody concentrations declined and remained suppressed for 3 years in the case of FLU-specific and for more than 5 years in the case of TT-specific antibodies.Conclusions. We found that MM is associated with a profound disease- and therapy-related immunosuppression, which is compensated for a few months after alloSCT, most likely by application of IVIG. This and the differences regarding the recovery of anti-FLU and anti-TT antibody titers during the following years need to be taken into account for optimizing IVIG application and immunization after alloSCT.

Sign in / Sign up

Export Citation Format

Share Document