OBJECTIVE: To evaluate the diagnostic efficacy of indirect haemagglutination assay (IHA) for detection of Schistosoma japonicum infections among boatmen and fishermen in Dongting Lake region, so as to provide insights into improving the schistosomiasis surveillance program among boatmen and fishermen. METHODS: The boatmen and fishermen were detected for S. japonicum infections using IHA and Kato-Katz technique or miracidium hatching test nylon gauze simultaneously at schistosomiasis testing sites in the anchor sites for boatmen and fishermen in the Dongting Lake region during the period from 2014 to 2016, and using IHA for serological screening followed by parasitological testing of seropositives during the period from 2017 to 2019. The sensitivity and specificity of IHA were evaluated for detection of S. japonicum infections among boatmen and fishermen, with the 2014-2016 parasitological testing results as a gold standard. In addition, the seroprevalence of S. japonicum infections was compared among boatmen and fishermen with different characteristics and among years. RESULTS: A total of 306 schistosomiasis testing sites were assigned for boatmen and fishermen, and a total of 143 360 person-time boatmen and fishermen were tested for S. japonicum infections in the Dongting Lake region from 2014 to 2019. The sensitivity and specificity of IHA were 69.9%, 97.3% and 96.1% (χ² = 74.6, P < 0.05), and 70.9%, 74.5% and 71.9% for detection of S. japonicum infections from 2014 to 2016 (χ² = 29.4, P < 0.05), respectively. The seroprevalence of S. japonicum infections reduced from 30.3% in 2014 to 1.8% in 2019 among boatmen and fishermen, appearing an overall tendency towards a decline (Z = 1 552.4, P < 0.05). In addition, male, individuals at ages of 45 to 60 years, full-time boatmen and fishermen were more likely to be seropositive for S. japonicum infections (all P values < 0.05). CONCLUSIONS The seroprevalence of S. japonicum infections appeared a tendency towards a decline among boatmen and fishermen in the Dongting Lake region year by year from 2014 to 2019. IHA presented a high efficacy for screening of S. japonicum infections among boatmen and fishermen in the Dongting Lake region.
Animals ; China/epidemiology* ; Hemagglutination ; Humans ; Lakes ; Male ; Middle Aged ; Prevalence ; Schistosoma japonicum ; Schistosomiasis/epidemiology* ; Schistosomiasis japonica/prevention & control* ; Seroepidemiologic Studies

hemagglutination titer of influenza virus, the reactivity to chicken and guinea pig red blood cell showed different results between egg propagated and cell propagated viruses. In the sequence analysis results for hemagglutinin and neuraminidase, no antigenic mutation was observed throughout all passages when cultured in MDCK-Sky3851 cells. On the other hand, mutations occurred in three amino acid sequences (H156R, G186S, S219F) in hemagglutinin up to 15 passages when cultured in eggs.CONCLUSION: H3N2 influenza virus cultured in eggs could lead mutations in amino acid sequence of hemagglutinin, distinct from the corresponding virus cultured in cells for which no antigenic mutation was observed. These findings suggest that cell culture is a more stable and effective way of production with lower risk of antigenic mutations for the manufacture of influenza vaccines.]]>
Amino Acid Sequence ; Animals ; Cell Culture Techniques ; Cell Line ; Chickens ; Eggs ; Erythrocytes ; Guinea Pigs ; Hand ; Hemagglutination ; Hemagglutinins ; Humans ; Influenza Vaccines ; Influenza, Human ; Neuraminidase ; Orthomyxoviridae ; Ovum ; Sequence Analysis ; Specific Pathogen-Free Organisms

hemagglutination (HA) abilities of two PDCoV strains (CH-01 and HNZK-04) were investigated. Our results showed that PDCoV has the ability to agglutinate rabbit erythrocytes after virion pretreatment with trypsin or neuraminidase. Additionally, the HA assay results showed a significant positive correlation with the infectious viral titer. Our results suggest that assessing the HA activity of PDCoV may be a useful diagnostic method for investigating and surveilling PDCoV infections.]]>
Coronavirus ; Diarrhea ; Erythrocytes ; Hemagglutination ; Methods ; Neuraminidase ; Population Characteristics ; Swine ; Trypsin ; Virion

PURPOSE: Enzyme-linked immunosorbent assay (ELISA) has been used in the diverse field to evaluate influenza virus infection; for the surveillance, diagnosis, efficacy evaluation, and development of the vaccine. The aim of this study was to establish an ELISA for detecting HA strain-specific antibodies using recombinant pandemic A H1N1 (pH1N1) HA1 (rHA1) protein. MATERIALS AND METHODS: rHA1 was produced in baculovirus system. The clinical performance of the developed ELISA was validated using human serum samples, by comparison with standard methods for detecting a neutralizing antibody; hemagglutination inhibition (HI) assay and microneutralization test (MNT). The ability of the ELISA system to evaluate the efficacy test of an influenza vaccine was explored by measuring antibody levels in the serum of vaccinated mice. RESULTS: Our ELISA could detect anti-rHA1 antibody in influenza-infected patients and vaccinated subjects. Compared to HI assay and MNT as reference methods, our method showed good performance in detection of anti-rHA1 antibody. Detection of the anti-rHA1 antibody in vaccinated mice and its correlation with titers in HI assay was also proved in a mice model. CONCLUSION: An ELISA system using rHA1 of pH1N1 influenza virus was developed, and showed good clinical performance in diagnosis of influenza virus infection and evaluation of the vaccination efficacy in both human and animal models.
Animals ; Antibodies ; Antibodies, Neutralizing ; Baculoviridae ; Diagnosis ; Enzyme-Linked Immunosorbent Assay* ; Hemagglutination ; Humans ; Influenza A virus ; Influenza Vaccines ; Influenza, Human* ; Methods ; Mice ; Models, Animal ; Orthomyxoviridae* ; Pandemics* ; Vaccination

To diagnose colibacillosis, detection of O-serogroups and virulence genes has been recommended worldwide. The prevalence of virulence factors can fluctuate over time. The objectives of this study were to determine the prevalence of O-serogroups, virulence genes, and F18 subtypes among pathogenic Escherichia coli isolated from weaned piglets with diarrhea in Korea. Between 2008 and 2016, 362 E. coli were isolated from weaned piglets with diarrhea. Hemolysis was determined in blood agar, and O-serogroups were identified using the slide agglutination technique. The genes for the toxins and fimbriae were amplified by polymerase chain reaction (PCR). Real-time PCR was conducted to discriminate between F18 subtypes. Although the most prevalent serogroup was O149 (11.3%) in the last 9 years, O139 (19.1%) became the most prevalent in recent years (2015–2016). The most predominant pathotype was enterotoxigenic E. coli (61.3%). The frequencies of Shiga-like toxin-producing E. coli (STEC) (23.4%), O139 (19.1%), Stx2e (35.1%), and F18ab (48.7%) increased over the most recent years. Although enterotoxigenic E. coli was the most predominant pathotype, the frequencies of O139, Stx2e, STEC, and F18ab have increased in recent years. These results demonstrate that there have been temporal changes in the predominant O-serogroups and virulence genes over the last decade in Korea. These findings can be practicable for use in epidemiology and control measures for enteric colibacillosis in Korean piggeries.
Agar ; Agglutination ; Diarrhea ; Enterotoxigenic Escherichia coli ; Epidemiology ; Escherichia coli ; Escherichia ; Hemolysis ; Korea ; Polymerase Chain Reaction ; Prevalence ; Real-Time Polymerase Chain Reaction ; Serogroup ; Shiga-Toxigenic Escherichia coli ; Virulence Factors ; Virulence

BACKGROUND: The recent expansion of knowledge about various ABO alleles has led to the need for a comprehensive measure to cover the numerous polymorphisms dispersed in the ABO gene. A few studies have examined the diversity of the O allele compared to A or B subgroup alleles, resulting in antigenic changes. This study investigated the relationship between the serologic and molecular genetic characteristics of the O alleles in the Korean population. METHODS: One hundred and five samples from healthy blood group O subjects were selected randomly. The isoagglutinin titer was measured using a tube agglutination and gel microcolumn assay. The ABO alleles were analyzed by sequencing exons 6 and 7 of the ABO gene. When the origin of a heterozygous nucleotide sequence was ambiguous, it was separated into a single allele using mono-allele amplification or cloning. RESULTS: The median IgM isoagglutinin titer was eight. In contrast, the median IgG anti-A and anti-B isoagglutinin titers were 64 and 32, respectively. The IgG isoagglutinin titer showed a significant increase with age (P<0.0001). Six O alleles were observed in 105 blood group O populations by sequencing. The O01 and O02 alleles were common (0.57, 0.36). Three rare O alleles (O04, O05, and O06) and one novel non-deletional O allele were found. CONCLUSION: The distribution of isoagglutinin titers of blood group O and the genetic frequency of O alleles in this study would form the basis of the development and interpretation of ABO genotyping and serologic workup in the Korean population.
Agglutination ; Alleles ; Base Sequence ; Clone Cells ; Cloning, Organism ; Exons ; Immunoglobulin G ; Immunoglobulin M ; Molecular Biology ; Sequence Analysis

Equine influenza (EI) is the main cause of respiratory illness in equines across the globe and is caused by equine influenza A virus (EIV-A), which has impacted the equine industry internationally because of the marginal mortality and high morbidity. In the present study, the immune responses after equine influenza vaccination were evaluated in 4,144 horses in Korea using the hemagglutination inhibition (HI) assay. The equine influenza virus (EIV), A/equine/South Africa/4/03 (H3N8), was used as the antigen in the HI assay. The mean seropositive rates were 89.2% (97.4% in 2016, 77.6% in 2017, and 92.4% in 2018). This paper highlights the advances in understanding the effects of vaccines and control strategies for mitigating the emerging menace by EIV.
Antibody Formation ; Hemagglutination ; Horses ; Influenza A virus ; Influenza, Human ; Korea ; Mortality ; Orthomyxoviridae ; Vaccination ; Vaccines

BACKGROUND: Automated systems are used widely for pre-transfusion tests in blood banks, in an attempt to reduce effort and human error. We evaluated the clinical performance of an automated blood bank system, ORTHO VISION (Ortho-Clinical Diagnostics, Switzerland), for blood cross-matching. METHODS: Saline cross-matching was performed for 93 tests using 56 samples. Coombs cross-matching was performed for 400 tests using 166 samples. Saline cross-matching was compared for the automated ORTHO VISION and manual tube methods. Coombs cross-matching was compared for the automated ORTHO VISION and manual column agglutination technique (CAT) methods. The evaluation of 32 antibody-positive samples using the automated ORTHO VISION and manual CAT methods was compared by performing 97 cross-matching tests. Additionally, the ORTHO VISION efficiency and carryover were evaluated. RESULTS: The concordance rate of the saline cross-matching results between the manual method and automated ORTHO VISION was 100%. The concordance rate of coombs cross-matching results between manual CAT and automated ORTHO VISION was 97.9%. The concordance rate of cross-matching for antibody positive samples between manual CAT and the automated ORTHO VISION was 97.9%. Coombs cross-matching was efficient using ORTHO VISION, whereas saline cross-matching was efficient using the tube manual method. CONCLUSIONS: ORTHO VISION showed reliable results for cross-matching and was more efficient than manual CAT for coombs cross-matching. Thus, ORTHO VISION can be used for pre-transfusion tests in blood banks.
Agglutination ; Animals ; Automation ; Blood Banks ; Cats ; Humans ; Methods

BACKGROUND/AIMS: Fecal calprotectin (Fcal) as well as the fecal immunochemical test (FIT) are useful biomarkers for detecting activity and mucosal healing in inflammatory bowel diseases. Here, we report the performance of simultaneous measurements of Fcal and FIT for ulcerative colitis (UC) patients using the newly-developed latex agglutination turbidimetric immunoassay (LATIA) system. METHODS: Fcal and hemoglobin were measured by the LATIA system in 152 UC patients who underwent colonoscopy. Fcal was also quantified with a conventional enzyme-linked immunosorbent assay (ELISA). Fecal markers were evaluated in conjunction with the mucosal status of UC, which was assessed via the Mayo endoscopic subscore (MES) classification. RESULTS: The LATIA system could quantify calprotectin and hemoglobin simultaneously with the same fecal samples within 10 minutes. The values of the Fcal-LATIA closely correlated with those of the Fcal-ELISA (Spearman rank correlation coefficient, r=0.84; P<0.0001). The values of Fcal for each assay and the FIT all significantly correlated with the MESs (Spearman rank correlation coefficient, Fcal-LATIA: r=0.58, Fcal-ELISA: r=0.55, and FIT: r=0.72). The mucosal healing predictability (determined by an MES of 0 alone) of the Fcal-LATIA, Fcal-ELISA, and FIT-LATIA with the cutoffs determined by receiver operating characteristic curve analysis was 0.79, 0.78, and 0.92 for sensitivity, respectively, and 0.78, 0.69, and 0.73 for specificity, respectively. CONCLUSIONS: The performance of the novel Fcal-LATIA was equivalent to that of the conventional Fcal assay. Simultaneous measurements with FITs would promote the clinical relevance of fecal biomarkers in UC.
Agglutination ; Biomarkers ; Classification ; Colitis, Ulcerative ; Colonoscopy ; Enzyme-Linked Immunosorbent Assay ; Feces ; Humans ; Immunoassay ; Inflammatory Bowel Diseases ; Latex ; Leukocyte L1 Antigen Complex ; ROC Curve ; Sensitivity and Specificity

Canine adenovirus type 1 (CAV-1) infection results in hepatitis in dogs. In this study, we investigated the biologic and genetic characteristics of the CAV-1 vaccine strain (CAV1V) to improve quality control about CAV vaccine. The identity of CAV1V as CAV-1 was confirmed based on its cytopathic effects and the results of hemagglutination (HA) and immunofluorescence assays, and electron microscopy. The CAV1V strain reached 10(7.5) TCID(50)/mL in MDCK cells at 4 days post-inoculation and exhibited hemmagglutination activity of 256 U using guinea pig erythrocytes. Intranuclear fluorescence in the infected cells was observed and typical adenoviruses were observed in electon microscope. CAV1V strain was identified as a CAV-1 strain by nucleotide sequence analysis. In a comparison of the nucleotide sequences of the fiber genes of several CAV strains, CAV1V showed the highest similarity (99.8%) with the GLAXO strain, which was isolated in Canada. Our biological characterization of CAV1V will facilitate quality control of the canine hepatitis vaccine.
Adenoviridae ; Adenoviruses, Canine ; Animals ; Base Sequence ; Canada ; Dogs ; Erythrocytes ; Fluorescence ; Fluorescent Antibody Technique ; Guinea Pigs ; Hemagglutination ; Hepatitis ; Madin Darby Canine Kidney Cells ; Microscopy, Electron ; Quality Control