Passive Hemagglutination Inhibition Research Articles

Persistence of passive immunity against some important viral diseases and feed conversion in chickens fed diet supplemented with probiotic

The ban of antibiotic growth promoters due to increased bacterial resistance and drug residues in poultry production, together with consumer's demand for “natural” products, have encouraged increase in the use of alternative growth promoters like probiotics. This study evaluated the effects of probiotic supplemented diet on the feed conversion ratio (FCR) and passive immunity against Newcastle disease (ND) and Infectious Bursal Disease (IBD) in chickens. Forty, one day-old broiler chicks were randomly selected into two groups: No probiotic and probiotic fed groups. The weight gained and FCR were monitored while blood samples for serum were collected from five birds per group weekly, for four weeks. Haemagglutination inhibition (HI) and passive HI tests were conducted to evaluate the levels of passive immunity (maternally derived antibody) in the different groups. There was a significant improvement in weight gain and FCR of birds fed the probiotics. Maternally derived antibody (MDA) against ND and IBD in the chicks were high at week 1. There was a delay in the decay of MDA against ND and IBD in the probiotic fed groups although MDA levels against both diseases were almost the same at week 3 in both probiotic fed and no probiotic groups. It could be concluded that probiotics can facilitate increased body weight, FCR and persistent passive immunity in chickens.

Certification of a New Batch of the Industry Reference Standard of Polysaccharide Content in Schigellvac Vaccine

The article summarises materials on the certification of the industry reference standard of Schigella sonnei polysaccharide dysentery vaccine (commercial name — Schigellvac). The industry reference standard is used to assess the consistency of the vaccine «Specific activity» testing by passive hemagglutination inhibition assay. A certification programme for the industry reference standard was developed. Samples of the candidate vaccine were tested in terms of the following quality characteristics: «Appearance», «Identification», «Extractable Volume». The test results confirmed that the samples comply with the current requirements of the manufacturer’s product specification file for Schigellvac vaccine. It was determined that the certification parameter — the polysaccharide dilution ratio which results in inhibition of passive hemagglutination in a homologous system — has to fall in the range from 1:128 to 1:512. The following set of standard documents accompanying a scientific/technological product was approved for the industry reference standard No. 42-28-386-2017: passport, patient information leaflet, mockup labels for primary and secondary packaging.

Epidemiology and Phylogenetic Analysis of Crimean-Congo Hemorrhagic Fever Viruses in Xinjiang, China

In 2004 and 2005, an epidemiological survey of Crimean-Congo hemorrhagic fever virus (CCHFV) was conducted in Xinjiang, China. A total of 5,629 serum samples of human and livestock were collected and tested for the CCHFV antibody, and 17,319 ticks were collected for viral identification. Reverse passive hemagglutination inhibition assays showed that the average prevalence of CCHFV antibody was 1.7% for the humans and 12.7% for the livestock. A relatively high antibody prevalence, ranging from 19.1% to 23.4%, was found in the livestock of the northwest, southwest, and northeast parts of the Tarim Basin. When the ticks were pooled to inoculate suckling mice, followed by reverse transcription-PCR (RT-PCR) to detect CCHFV RNA, the average RT-PCR-positive rates for Hyalomma asiaticum kozlovi and H. asiaticum asiaticum were 12.9% and 2.6%, respectively. A significant correlation was found between the antibody prevalence in the livestock and the CCHFV prevalence in H. asiaticum of the same geographic region. No CCHFV RNA was detected in Dermacentor nivenus, Rhipicephalus turanius, or Rhipicephalus sanguineus. A total of 27 partial S segments of CCHFVs were sequenced and used for phylogeny analysis. All but one Chinese isolate grouped into the Asia 1 clade, which contains the strains from Xinjiang and Uzbekistan, while the other strain, Fub90009, grouped with strains from the Middle East.

Recombinant human immunoglobulin (Ig)A1 and IgA2 anti‐D used for detection of IgA deficiency and anti‐IgA

To avoid anaphylactic reactions, immunoglobulin (Ig)A-deficient patients with anti-IgA should be transfused with IgA-deficient blood components. There is a need for fast and robust assays for demonstration of IgA deficiency and for detection of anti-IgA. Recombinant human IgA1 and IgA2 anti-D molecules were constructed, expressed in Chinese hamster ovary cells, and purified. These antibodies were used to sensitize group O D+ red blood cells (RBCs) for use as indicator cells, either in the format of a passive hemagglutination inhibition assay for detection of IgA deficiency or in a passive hemagglutination assay for detection of anti-IgA. Both assays were performed in gel card. The sensitivity for IgA detection was adjusted to approximately 100 ng per mL. The assay for demonstration of IgA deficiency correlated with an enzyme-linked immunosorbent assay for quantification of IgA. Anti-IgA were easily detected, and the reactivity with IgA anti-D-sensitized RBCs could be inhibited by purified IgA1 and/or IgA2 and by normal plasma containing IgA but not by IgA-deficient plasma. Anti-IgA was found in 64 percent of IgA-deficient donors with less than 3 ng of IgA per mL. The assays for detection of IgA and anti-IgA described in this article are fast and robust. Furthermore, they are applicable in all standard blood typing laboratories and are therefore well suited for immediate investigation of transfusion reactions.

Development of passive haemagglutination (PHA) and haemagglutination inhibition (HAI) technique for potency estimation of Cobra Antisnake Venom Serum (ASVS)

Antibodies against snake venom or antivenom potency are assayed quantitatively by in-vivo neutralization test in mice, which requires large number of laboratory animals. In potency assays of biological substances such as antivenoms, it is highly desirable to avoid suffering and death of animals by substituting in-vivo method with in-vitro methods, provided such methods measure life-saving capability with precision similar to that of in-vivo method. The in-vitro tests determine the neutralizing power of antivenom by permitting the evaluation of a particular biological activity of the venom and its neutralization after mixing the venom with the antivenom [Theakston RDG, Reid HA. Development of simple standard assay procedures for the characterization of snake venom. Bull WHO 1983;61:949–956; Gutierrez JM, Rojas G, Lomonte B, Gene JA, Chaves F, Alvarado J, et al. Standardizing of assays for testing the neutralizing ability of antivenoms. Toxicon 1990;28:1127–1129; Theakston R.D.G. Comments on letter of Gutierrez et al. on standardization of assays for testing the neutralizing ability of antivenoms. Toxicon 1990;28:1131–1132; Harvey AL, Barfaraz A, Thomson E, Faiz A, Preston S, Harris JB. Screening of snake venom for neurotoxic and myotoxic effects using simple in-vitro preparation from rodents and chicks. Toxicon 1994;32:257–265; World Health Organization Progress in characterization of venom and standardization of anti-venoms. Geneva: WHO offset publication; 1981. p. 58.]. Hence, the ideal requirements for an assay in detecting venom and venom antibody include high level of sensitivity, specificity (ability to differentiate between venom and venom antibody produced by closely related species of snakes), reproducibility and simplicity. A new in-vitro procedure for quantitative analysis of potency of ASVS by passive haemagglutination (PHA) and haemagglutination inhibition (HAI) has been explored. The methods described are simple, rapid, economical, reproducible and useful in replacing the more expensive in-vivo neutralization assays. Moreover, it also eliminates the use of laboratory animals.

A novel erythrocyte-based immunoassay for simultaneous detection of both antimycobacterial antibody response and mycobacterial antigen in human serum samples of pulmonary tuberculosis and a control group of patients using ‘a single probe’

A modified passive hemagglutination using double aldehyde stabilized cells (tanned sheep erythrocytes treated with glutaraldehyde and pyruvic aldehyde) was evaluated for detection of both antimycobacterial antibodies and circulating mycobacterial antigens simultaneously in human serum samples from patients with pulmonary tuberculosis (n=40) and a control group (n=44). Double aldehyde stabilized cells sensitized with an optimum dose of 200 microg mL(-1) of sonicate extract of Mycobacterium tuberculosis antigens was used as single probe to detect both antibodies and antigen, respectively, by passive hemagglutination and passive hemagglutination inhibition. The sensitivity limit of passive hemagglutination inhibition was determined to be 280 ng mL(-1) using a dose-response curve. Sensitivity of passive hemagglutination and passive hemagglutination inhibition, respectively, was 90% and 52.5%, and specificity was 91% and 100%. Although passive hemagglutination and passive hemagglutination inhibition need further evaluation, these erythrocyte-based immunoassays are potentially advantageous, especially as double aldehyde stabilized sensitized cells could be used as a single probe for detection of both antibodies and antigen. In addition, erythrocyte-based immunoassays are rapid, simple and cost-effective with a high degree of sensitivity.

Aseptic meningitis syndrome due to enterovirus and Leptospira sp in children of Salvador, Bahia

For the purpose of identifying the frequency that enterovirus, leptospires, arbovirus cause aseptic meningitis syndrome (AMS) during non-epidemic periods and comparing patients with and without laboratory evidence for an etiologic agent, 112 patients were selected aged between 3 months and 15 years and a clinical suspicion of AMS and were referred to Couto Maia Hospital, the Infectious and Parasitic Disease Reference Center for Salvador, Bahia. In 44.6% (n=50), the etiologic agent for the diagnosis was laboratory-confirmed: enterovirus was identified in 37.7% (n=42) of the cases by the PCR Amplicor diagnostic kit, cerebrospinal fluid or fecal culture isolation; Leptospira sp. in 7.12% (n=8) by the microagglutination test; and arbovirus in non of the cases by inhibition of passive hemagglutination. In 14 of the 22 enteroviral isolates that were evaluated, 6 different serotypes were identified with Echovirus-4 being the major serotype (27.2%; 6/22) among all found (Coxsackie B2, B3, B6 and B9; Enterovirus 71). In conclusion, enteroviruses were the most frequent etiologic agent of AMS and that leptospirosis should be included in the differential diagnosis. In addition, patients with and without laboratory-confirmed identification of the etiologic agent had similar demographic and clinical characteristics and cerebrospinal fluid findings (p >0.05), therefore suggesting that patients without a confirmed diagnosis had enteroviral or leptospiral etiologies.

Detection of Crimean-Congo haemorrhagic fever virus antibodies in humans and imported livestock in Saudi Arabia

A survey of Crimean-Congo haemorrhagic fever virus antibody, using the reversed passive haemagglutination inhibition test, was carried out in Saudi Arabia on sera from imported livestock at Jeddah seaport, as well as humans who had contact with imported animals on farms and in quarantine stations. Antibodies were detected in 3/354 (0·8%) humans, 88/2162 (4·1%) sheep, 14/432 (3·2%) goats and 1/182 (0·6%) cattle. Camel and horse sera were negative. The Sudanese small ruminants had the highest seropositivity rate, strongly suggesting that the virus was introduced from Sudan into Saudi Arabia. Contact with imported animals was not an apparent risk factor for virus transmission to humans.

Immune responses to inactivated vaccine in people naturally infected with hantaviruses

An inactivated Hantaan virus vaccine for hemorrhagic fever with renal syndrome (HFRS) was given by injection to 15 people who were naturally infected with either Hantaan or Seoul viruses. Immunofluorescent antibody (IFA), reversed passive hemagglutination inhibition (RPHI), hemagglutination inhibition (HI), and neutralization antibody (NA) assays were used to measure the antibody titers of the vaccinated people before and after three doses of vaccine. The results indicated that IFA and RPHI antibody titers were boosted significantly (P < 0.05) after the vaccination. Either Hantaan or Seoul virus could induce two-way cross-reactive neutralization antibody responses in humans. After HTNV vaccine immunization, the NA titers of people with natural infection increased significantly (P < 0.05) to both Hantaan and Seoul viruses, while the relative dominance between these two type responses was still similar to that of natural infection. It is worthwhile to studying the procedure further to inoculate two different virus vaccines for improving the cross-protective effect. © 1996 Wiley-Liss, Inc.

Immune responses to inactivated vaccine in people naturally infected with hantaviruses.

An inactivated Hantaan virus vaccine for hemorrhagic fever with renal syndrome (HFRS) was given by injection to 15 people who were naturally infected with either Hantaan or Seoul viruses. Immunofluorescent antibody (IFA), reversed passive hemagglutination inhibition (RPHI), hemagglutination inhibition (HI), and neutralization antibody (NA) assays were used to measure the antibody titers of the vaccinated people before and after three doses of vaccine. The results indicated that IFA and RPHI antibody titers were boosted significantly (P < 0.05) after the vaccination. Either Hantaan or Seoul virus could induce two-way cross-reactive neutralization antibody responses in humans. After HTNV vaccine immunization, the NA titers of people with natural infection increased significantly (P < 0.05) to both Hantaan and Seoul viruses, while the relative dominance between these two type responses was still similar to that of natural infection. It is worthwhile to studying the procedure further to inoculate two different virus vaccines for improving the cross-protective effect.

Conservative treatment of robin sequence — Risk of asphyxia

In November 1984 a case of Crimean-Congo haemorrhagic fever (CCHF) occurred in a worker who became ill after slaughtering ostriches (Struthio camelus) on a farm near Oudtshoorn in the Cape province of South Africa. The diagnosis was confirmed by isolation of CCHF virus from the patient's serum and by demonstration of a specific antibody response. It was suspected that infection was acquired either by contact with ostrich blood or by inadvertantly crushing infected Hyalomma ticks while skinning ostriches. Reversed passive haemagglutination-inhibition antibody to CCHF virus was detected in the sera of 2292 ostriches from farms in Oudtshoorn district, including 69 from the farm where the patient worked, but not in the sera of 460 birds of 37 other species. In pathogenicity studies domestic chickens proved refractory to CCHF infection, but viraemia of low intensity (maximum titre 2.5 log10 mouse ic LD50/ml) followed by a transient antibody response occurred in blue-helmeted guinea fowl (Numidia meleagris). These results offer the first direct evidence that some bird species are susceptible to CCHF virus infection.

Screening for IgA deficiency on the Olympus PK7100 by haemagglutination inhibition

Severe or life-threatening anaphylactic reactions during blood transfusion to patients with anti-IgA, though infrequent, can be avoided by transfusing blood products prepared from IgA deficient donors. This report describes the development and use a passive haemagglutination assay adapted for use on the Olympus PK7100 blood group analyser. Donor plasma samples identified as being presumptive IgA deficient were further screened by a manual passive haemagglutination inhibition technique and finally confirmed by means of a quantitative enzyme-linked immunosorbent assay. Of 5723 donors tested simultaneously for IgA deficiency, blood grouping and red cell antibody screening, six (1 in 954) were confirmed as IgA deficient (i.e. < 100 ng/ml of IgA). The test is simple and cost effective and can be used to establish a database of IgA-deficient donors.

Plague surveillance in Brazil: 1983-1992.

Plague caused by Yersinia pestis, has persisted in Brazil in several natural foci spread throughout rural areas in the States of Ceara, Paraiba, Pernambuco, Piaui, Rio Grande do Norte, Alagoas, Bahia, Minas Gerais and Rio de Janeiro. Nationwide surveillance of plague in Brazil based on serological testing started in 1983. We now present an update report of the examinations carried out in our laboratory from 1983 to 1992. The passive hemagglutination test for antibodies against fraction 1A antigen of Y. pestis and the passive hemagglutination inhibition control were employed for testing a total of 220,769 sera. Samples analyzed included 2,856 sera from clinically diagnosed plague cases or suspects, 49,848 sera from rodents of 24 species and 2 species of small wild carnivores (marsupials), 122,890 sera from dogs, and 45,175 sera from cats. Specific antibodies were found in 92 (3.22%) human sera; 143 (0.29%) sera from rodents of 8 species and from the two species of marsupials, 1,105 (0.90%) sera from dogs and 290 (0.64%) sera from cats. The presence of significant levels of specific anti-F1A antibodies among rodents and wild or domestic carnivores (dogs and cats) indicates that all the Brazilian plague foci remain active in spite of the absence of human cases in some of them.

Hemagglutination Assays for the Diagnosis and Prevention of IgA Anaphylactic Transfusion Reactions

Passive hemagglutination assays (PHA) may be used to detect IgA antibodies to confirm clinical diagnoses of suspected IgA anaphylactic transfusion reactions. Passive hemagglutination inhibition assays (PHIA) may be used to identify IgA-deficient blood donors whose plasma-containing components are transfused to prevent anaphylactic transfusion reactions in prospective recipients at risk because of the presence of IgA antibodies. Using a standard PHA, we detected class-specific anti-IgA in 76.3% of 80 IgA-deficient patients with a history of an anaphylactic transfusion reaction, and in 21.7% of 97 asymptomatic IgA-deficient blood donors or their IgA-deficient family members. Using PHIA, we confirmed IgA deficiency (< 0.05 mg/dL) for the donors of 525 plasma-containing blood components that were transfused without acute clinical reactions to 48 IgA-deficient recipients with anti-IgA and/or a history of an anaphylactic transfusion reaction. The frequency of IgA-deficiency with class-specific anti-IgA among 32,376 random blood donors was 0.08% (1/1,200). The combined use of PHA for detecting anti-IgA and PHIA for measuring IgA concentration provides an effective and safe strategy for the diagnosis and prevention of IgA anaphylactic transfusion reactions. However, PHA for anti-IgA lacks specificity for identifying persons who are truly at risk for significant anaphylactic transfusion reactions. The consequence is an overdiagnosis of IgA anaphylactic transfusion reactions and an overestimation of the number of persons at risk for IgA anaphylactic transfusion reactions because of the detection of an IgA antibody in their serum.

Hemagglutination assays for the diagnosis and prevention of IgA anaphylactic transfusion reactions

Passive hemagglutination assays (PHA) may be used to detect IgA antibodies to confirm clinical diagnoses of suspected IgA anaphylactic transfusion reactions. Passive hemagglutination inhibition assays (PHIA) may be used to identify IgA-deficient blood donors whose plasma- containing components are transfused to prevent anaphylactic transfusion reactions in prospective recipients at risk because of the presence of IgA antibodies. Using a standard PHA, we detected class- specific anti-IgA in 76.3% of 80 IgA-deficient patients with a history of an anaphylactic transfusion reaction, and in 21.7% of 97 asymptomatic IgA-deficient blood donors or their IgA-deficient family members. Using PHIA, we confirmed IgA deficiency (&lt; 0.05 mg/dL) for the donors of 525 plasma-containing blood components that were transfused without acute clinical reactions to 48 IgA-deficient recipients with anti-IgA and/or a history of an anaphylactic transfusion reaction. The frequency of IgA-deficiency with class-specific anti-IgA among 32,376 random blood donors was 0.08% (1/1,200). The combined use of PHA for detecting anti-IgA and PHIA for measuring IgA concentration provides an effective and safe strategy for the diagnosis and prevention of IgA anaphylactic transfusion reactions. However, PHA for anti-IgA lacks specificity for identifying persons who are truly at risk for significant anaphylactic transfusion reactions. The consequence is an overdiagnosis of IgA anaphylactic transfusion reactions and an overestimation of the number of persons at risk for IgA anaphylactic transfusion reactions because of the detection of an IgA antibody in their serum.

Passive hemagglutination inhibition test for diagnosis of brown recluse spider bite envenomation

Our goal was to recreate a passive hemagglutination inhibition (PHAI) test to diagnose brown recluse spider (BRS; Loxosceles reclusa) bite envenomation for treatment trials. Guinea pigs received intradermal injections of concentrated spider venom from the following species: Loxosceles reclusa, Argiope aurantia, Argiope trifasciata, Phidippus audax, and Lycosa frondicola. Skin lesion exudate was collected and tested with the BRS venom PHAI assay. From 51 separate collections of exudate, test sensitivity was 90% as long as 3 days after venom injection. Specificity was 100% with venom from the other spider species listed above in vivo (7 test samples) and in vitro (5 test samples), as well as with random bacterial exudate with and without added serial dilutions of BRS venom (10 test samples). The test was reproducible over repetitive assays to within one 10-fold dilution. A positive PHAI test result could function as an entry criterion for BRS bite victims in human treatment trials.

Laboratory tests to exclude IgA deficiency in the investigation of suspected anti-IgA transfusion reactions.

Four methods were compared as to their suitability for excluding IgA deficiency in the investigation of suspected anti-IgA transfusion reactions. The methods were radial immunodiffusion, passive hemagglutination inhibition, sandwich enzyme-linked immunosorbent assay, and membrane enzyme immunoassay. Parallel testing was performed on sera from 40 patients or blood donors previously found to have anti-IgA and low or undetectable levels of IgA. All test methods identified the 40 sera as having abnormally low IgA levels. The membrane enzyme immunoassay required 10 minutes or less for testing, as compared to 3 hours for passive hemagglutination inhibition, 4 hours for sandwich enzyme-linked immunosorbent assay, and 48 hours for radial immunodiffusion. The membrane enzyme immunoassay offers the potential for a rapid, instrument-free screen of IgA levels and therefore may be useful in identifying those patients with suspected anti-IgA anaphylactic transfusion reactions who are not IgA deficient and do not require IgA-deficient blood components for additional transfusions.

Involvement of dogs in plague epidemiology in Tanzania. Serological observations in domestic animals in Lushoto District.

Venous blood was collected aseptically from clinically healthy domestic dogs, goats, sheep, cats and fowl in various plague-infected villages of Lushoto District, Tanzania, at the time when the disease was actively prevalent in the area. Flea ectoparasites were collected from the animals, processed, identified and counted. Serum samples were tested for specific plague antibodies, using the passive haemagglutination technique and checked by passive haemagglutination inhibition tests. Altogether 389 animals, of which 201 were domestic dogs, were involved. 11 (5.5%) dogs had significantly elevated specific plague antibodies at titres ranging from 20 to 1280. All the dogs were also heavily infested with fleas at a mean index of 7.7 fleas per animal. Of 1,871 fleas collected from the dogs, 93.8% were Ctenocephalides felis and 6.2% were C. canis. All the other animals examined were negative for plague. It was concluded that domestic dogs could play an important role as plague carriers in the area and that the animals could serve as sentinel animals for the detection of plague in villages where human plague outbreaks have not previously occurred.

A decade of plague epidemiology and control in the Western Usambara mountains, north-east Tanzania

Outbreaks of human plague have been occurring in the Western Usambara mountains since 1980, involving many cases and deaths. Epidemiological surveys and control activities were carried out from June 1980 to May 1990. Rodents were trapped live, identified and serologically tested for plague, using the passive haemagglutination and passive haemagglutination inhibition tests. Rodent fleas were collected, processed, identified and counted. House fleas were caught with light traps and similarly treated. People and domestic carnivores were serologically tested for the disease. Various plague control measures were undertaken. A total of 2433 animals, 2254 rodent fleas and 1366 house fleas were collected. Average indices of rodent and house fleas were 0.93 and 5.38 respectively. Rattus rattus and Mastomys natalensis were the most abundant rodent species. Xenopsylla brasiliensis and Dinopsyllus lypusus were their commonest flea ectoparasites while Pulex irritans was the major house flea. Of 2044 rodent, 1880 human and 176 dog sera tested, 5.5%, 0.5% and 6.3% respectively were positive. It was concluded that plague was active in the focus despite the control measures and that common reservoirs and efficient vectors were present. It was suggested that dogs were probably involved in the epidemiology of the disease, that P. irritans was not susceptible to the insecticide used and that the flea was probably involved in murine plague transmission. Bacteriological research on the causative agent to establish the nature of its long persistence in the area and maintenance of a surveillance service are recommended.

A rapid screening test for detection of IgA deficiency

A solid-phase red cell adherence (SPRCA) assay has been developed to screen blood donors for IgA deficiency, and 6117 donor sera have been screened by this method. Eighteen sera were found to be IgA deficient, which represents a frequency of 1 in 340. Seventeen of these sera were retested by passive hemagglutination inhibition, which has a sensitivity of approximately 0.1 mg per dL. Eight sera were confirmed as IgA deficient, and nine were found to contain low levels of IgA (less than 1 mg/dL). The approximate sensitivity of the SPRCA assay is 1 mg per dL. The speed, simplicity, and sensitivity of this assay make it a good alternative to conventional methods of screening.