Virus ELISA Research Articles

Bovine viral diarrhea virus infections in pigs: why is this situation important for Brazilian herds?

ABSTRACT: Swine can be infected by the bovine viral diarrhea virus (BVDV) under natural conditions. For this reason, further information and divulgation are needed regarding the pathogenicity of this virus in swine. This infection is practically unknown in the realm of pig farming, and, as it shares some similarities with the classical swine fever virus (CSFV), its diagnosis becomes a challenge for official sanitary programs. Studies have shown the absence of clinical signs in piglets and reproductive problems in sows due to BVDV infections. There is little research on the prevalence, risk factors, preventive measures and control of BVDV in pigs around the world. And in Brazil, the data is practically non-existent. At the time of diagnosis, comparing the most efficient laboratory tests such as virus neutralization, ELISA, RT-PCR, and immunofluorescence so as to minimize the risk of cross serological reactions when dealing with a persistent or transient infection, can be an important tool. Moreover, the practical implications for CSFV eradication programs are a main reason for the development of further research against this infection. Therefore, this paper aims to review various aspects of BVDV infection in pigs, and how this information can be important for Brazilian herds.

P004 Retrospective analysis of deceased donor samples for ZIKA virus infection in high-risk population, a three-year study

Aim The recent epidemic of Zika Virus in the United States has necessitated screening for the presence of this agent in high-risk transplant solid organ donors to avoid the transmission to potential recipients. In this study, we performed a retrospective analysis of Cadaver Donors from Auxilio Mutuo Hospital (HAM) in Puerto Rico. Methods One hundred fifty-six (156) serum samples from Deceased Donors were obtained from Puerto Rico. Aliquots of serum, were maintained at −20 °C since collection. There were 38 samples from 2014, 62 from 2015, and 56 from 2016. These samples were tested with the RealStar® Zika Virus RT-PCR Kit U.S.® kit (Altona Diagnostics), and Anti-Zika Virus ELISA IgG and IgM kits (EUROIMMUN). These assays were validated with a separate group of freshly obtained Zika-positive samples from an ambulatory clinic at HAM. Results Of the 156 total deceased donor specimens retrospectively tested, none were positive for PCR, 2 were positive for IgM, and 22 were positive or borderline for IgG. The breakdown over the 3-year period indicated an increase in long-term exposure, as indicated by the increase in IgG positive samples. In 2014, only 5.2% were positive. However, by 2015 19.4% of the samples were positive. This indicates that almost 20% of the Deceased Donors tested had some contact with the Zika Virus (or a related Flavivirus , such as Dengue or West Nile). Of the positive IgG samples, only 2 were positive for IgM, indicating the exposure was likely more than 3 months prior. The results of the PCR study were not surprising, as we have seen in our laboratory, the long-term storage of serum for later RNA-based PCR testing has been unsuccessful. Conclusions Zika testing utilizing PCR-based assays in conjunction with serological assays in areas of known infection is essential, especially when servicing solid organ transplant programs. The use of donors potentially infected with Zika virus could have a significant impact in transplant success as there are some indications that immunocompromised individuals may develop more severe symptoms or illnesses. The correct storage of serum samples is crucial to obtain reliable results of this test.

Hepatitis E virus antibodies in HIV-infected patients and blood donors from western Poland: A preliminary report.

Hepatitis E virus (HEV) infection is an emerging problem in industrialized countries, including Europe. Little data exists on HEV seroprevalence in Poland. The aim of this study was to assess the prevalence of anti-HEV IgG antibodies in Polish patients infected with the human immunodeficiency virus (HIV) and blood donors. Two hundred and ten individuals (n = 105 of HIV-infected patients and n = 105 of ageand sex-matched blood donors from the same area; 178 men and 32 women), aged 18-50 (median age: 38 years), were tested for the presence of anti-HEV IgG antibodies with the EUROIMMUN Anti-Hepatitis E Virus (HEV) ELISA (IgG) tests (Lübeck, Germany). Additionally, some simple clinical and laboratory data was collected. The overall anti-HEV IgG prevalence was 2.4% (5/210). One HIV-positive patient (0.95%) and 4 blood donors (3.8%) were seropositive (p = 0.1745). All the HEV-exposed individuals were men with a history of travel abroad and no icteric disease in the past. Exposure to HEV infection among Polish HIV patients and blood donors seems to be uncommon. Data on this issue is scarce and conflicting for HIV-infected individuals. Further investigations applying different serological tests and concomitant HEV RNA testing are needed to reliably assess the risk and practical impact of HEV infection in Poland.

Rapid and sensitive insulated isothermal PCR for point-of-need feline leukaemia virus detection.

ObjectivesFeline leukaemia virus (FeLV), a gamma retrovirus, causes diseases of the feline haematopoietic system that are invariably fatal. Rapid and accurate testing at the point-of-need (PON) supports prevention of virus spread and management of clinical disease. This study evaluated the performance of an insulated isothermal PCR (iiPCR) that detects proviral DNA, and a reverse transcription (RT)-iiPCR that detects both viral RNA and proviral DNA, for FeLV detection at the PON.MethodsMycoplasma haemofelis, feline coronavirus, feline herpesvirus, feline calicivirus and feline immunodeficiency virus were used to test analytical specificity. In vitro transcribed RNA, artificial plasmid, FeLV strain American Type Culture Collection VR-719 and a clinical FeLV isolate were used in the analytical sensitivity assays. A retrospective study including 116 clinical plasma and serum samples that had been tested with virus isolation, real-time PCR and ELISA, and a prospective study including 150 clinical plasma and serum samples were implemented to evaluate the clinical performances of the iiPCR-based methods for FeLV detection.ResultsNinety-five percent assay limit of detection was calculated to be 16 RNA and five DNA copies for the RT-iiPCR, and six DNA copies for the iiPCR. Both reactions had analytical sensitivity comparable to a reference real-time PCR (qPCR) and did not detect five non-target feline pathogens. The clinical performance of the RT-iiPCR and iiPCR had 98.82% agreement (kappa[κ] = 0.97) and 100% agreement (κ = 1.0), respectively, with the qPCR (n = 85). The agreement between an automatic nucleic extraction/RT-iiPCR system and virus isolation to detect FeLV in plasma or serum was 95.69% (κ = 0.95) and 98.67% (κ = 0.85) in a retrospective (n = 116) and a prospective (n = 150) study, respectively.Conclusions and relevanceThese results suggested that both RT-iiPCR and iiPCR assays can serve as reliable tools for PON FeLV detection.

No serological evidence for Zika virus infection and low specificity for anti-Zika virus ELISA in malaria positive individuals among pregnant women from Madagascar in 2010.

It was previously reported that a malaria infection may interfere with the specificity of a commercial ELISA test against Zika virus (ZIKV). We analyzed 1,216 plasma samples from healthy, pregnant women collected in two sites in Madagascar in 2010 for ZIKV antibodies using a commercial ELISA and for Plasmodium infection by PCR. This screen revealed six putative ZIKV-positive samples by ELISA. These results could not be confirmed by indirect immunofluorescence assays or virus neutralization tests. Four of these six samples were also positive for P. falciparum. We noted that the frequency of malaria positivity was higher in ZIKV-ELISA positive samples (50% and 100% in the two study sites) than ZIKV-negative samples (17% and 10%, respectively), suggesting that malaria may have led to false ZIKV-ELISA positives.

CD8+ T cells from healthy blood bank donors secrete antiviral levels of interferon-alpha

Abstract Background CD8+ T cells play important roles in the antiviral immune response to HIV-1 infection. Variation in the antiviral activities of CD8+ T cells among HIV-1-infected persons has been associated with disease state and clinical prognosis. However, the anti-HIV activities of CD8+ T cells from healthy uninfected blood donors have not been fully established. Methods In this study we assessed the ability of peripheral blood CD8+ T cells from healthy blood bank donors to inhibit HIV-1-replication. Co-culture assays were performed with CD8+ T cells and acutely HIV-1-infected primary CD4+ T cells. Also, CD8+ T cells were cultured and the derivative supernatants were evaluated in virus inhibition assays, ELISAs, and multiplex cytokine arrays. Results Variation was observed among CD8+ T cells from different blood donors in the ability to suppress HIV-1 replication. In the absence of stimulation, the CD8+ T cells, or their derivative fluids, lacked any appreciable anti-HIV activity. After PHA or anti-CD3/CD28 stimulation, the majority of CD8+ T cells and derivative fluids exhibited anti-HIV activity. Low levels of interferon-alpha were present in the CD8+ T cell fluids having increased anti-HIV activity, whereas CD8+ T cell fluids lacking anti-HIV activity contained undetectable levels of interferon-alpha. Other soluble factors present at increased levels in CD8+ T cell fluids having anti-HIV activity included TNF-beta, IL-8, IP-10, and TRAIL. Conclusions Our findings indicate that the secretion of antiviral levels of interferon-alpha is a normal function of CD8+ T cells in response to activation and stimulation. Variation in this immune response may influence host susceptibility to infection and disease.

MEASLES VIRUS IMMUNITY LEVEL STUDY IN PARTICULAR POPULATION GROUPS OF THE REPUBLIC OF GUINEA WITHIN THE FRAMEWORK OF GLOBAL MEASLES ELIMINATION PROGRAM. REPORT 2

A goal for measles elimination globally by 2010–2020 was recognized as one of the priorities in the WHO program “Health for All in the 21st Century” (1998). However measles outbreaks occurred in 2010–2016 in countries with high level of measles vaccine coverage including USA and some European countries.Large measles outbreaks were also registered on the African continent and particular in the Republic of Guinea as a result of the decline of measles vaccine coverage due to the Ebola virus epidemic in the Republic of Guinea in 2014–2015. WHO recommends carrying out the routine measles vaccination as well as the supplemental immunization activities after the stop of the Ebola virus transmission. Effectiveness of the activities is definitely connected with the detection of the epidemically significant for the supplemental immunization age groups. The aim of the study was to evaluate the measles immunity level in different age groups of population in the Republic of Guinea. Materials and methods. Twenty five blood serum samples of healthy adult Guineans aged 28–66 and 121 blood serum samples of adolescences and adults admitted to hospital in the town of Kindia (Republic of Guinea) for indoor treatment were tested by ELISA. The specific measles virus antibodies were detected using the following commercial ELISA test-systems produced by Euroimmun Medizinische Labordiagnostika AG Company (Germany): IgM-antibodies — by “Anti-Measles Virus ELISA (IgM)”, IgG-antibodi es — by “Anti-Measles Virus ELISA (IgG)”, IgG-avidity measles virus antibodies — by “Avidity: Anti-Measles Virus ELISA (IgG)”. A part of sera was studied by “Vector-Best IgM-measles” and “Vector-Best IgG-measles” ELISA test-systems (Russia). Results and discussion. The comparative quantitative study of the measles immunity level (i.e. IgG-antibodies titers) of the healthy adult Guineans in 2015 and 2016 revealed the lack of IgGantibodies in serum of only one person aged 30. In 68.7% of cases studied the IgG-antibodies titers didn’t change significantly during the year. In the most part (68.0%) of the 25 tested sera the high levels of the IgG-antibodies titers were detected (≥ 1000 IU/L). In addition the IgG-antibodies of high avidity were revealed in the most part (87.5%) of blood serum samples thus evidencing the history of measles virus infection in the past among the examined adults aged 28+. The ELISA studies of 121 blood serum samples from patients with different clinical diagnosis being on indoor treatment in the hospital of the town of Kindia (Republic of Guinea) revealed 21 anti-measles IgG negative patients. Among patients with the known age (n = 113) IgG-antibodies to measles virus were determined in 78.8% of the samples tested. At the same time in each age group the seronegative patients as well as the patients with low titers of the specific IgG-antibodies to measles virus were revealed. Among patients of 18–40 years of age the part of seronegative patients was equal to 28.5±5.1%. This cohort may be susceptible to measles virus infection and facilitate the support as well as the development of active epidemic process in case of measles outbreaks in the Republic of Guinea.

COMPARISON OF THE APPLICATION OF DOMESTIC «ELISA-IGM-DENGUE» KIT, DELIVERED IN THE D.I. IVANOVSKY INSTITUTE OF VIROLOGY (MOSCOW, RUSSIAN FEDERATION) AND «ANTI-DENGUE VIRUS ELISA IGM» KIT (EUROIMMUN, GERMANY) FOR THE SERODIAGNOSIS OF DENGUE FEVER

88 sera from patients with dengue fever were examined with the use of two test systems: Pilot Production kit «ELISA- IgM-dengue», delivered in the D.I. Ivanovsky Institute of Virology (Russian Federation) and. All 88 samples were positive for specific IgM in «ELISA-IgM-dengue», but 8 cases examined with the test kit «Anti-Dengue virus ELISA (IgM)» (Euroimmun, Germany) appeared to be negative. The ratio between the titers of anti-dengue IgM determined in patients’ blood samples by "ELISA-IgM-dengue" and «Ratio» (index, recommended by the company «Euroimmun» for differentiation of positive, equivocal or negative results, was evaluated. 53 blood sample containing M antibodies to cytomegalovirus (n = 43), Epstein-Barr virus (n = 6), herpes simplex virus (n = 2) and rubella virus (n = 2) were tested by both ELISA kits to compare their specificity. When «ELISA- IgM-dengue» kits were applied all observed samples were negative, but under the application of the «Anti-Dengue virus ELISA (IgM)» kit (Euroimmun, Germany) 17 samples (32.1%) were false positive or equivocal.

MEASLES VIRUS IMMUNITY LEVEL STUDY IN PARTICULAR POPULATION GROUPS OF THE REPUBLIC OF GUINEA WITHIN THE FRAMEWORK OF GLOBAL MEASLES ELIMINATION PROGRAM. REPORT 1

Measles remains one of the main reasons for child mortality in developing countries and periodically leads to the emergence of large outbreaks in different countries. This problem became especially urgent after WHO accepted the strategic plan to fight against measles. The plan has set the goal to decrease measles on a global scale. In 20102011 the large outbreaks of measles were registered on the African continent: in the Democratic Republic of Congo in the south of Africa, in Nigeria and in some other African countries. In the Republic of Guinea vaccination against measles is carried out singly to children aged 9 months. In 20142015 the increase of measles incidence was noted. Materials and methods. Using ELISA 22 blood serum samples of healthy adult Guineans aged 2471 and 136 blood serum samples received from children and adults the patients of hospital in the town of Kindi (Republic of Guinea) have been examined. The clinical samples were received in 20152016. The following test systems were used: the test systems produced by Euroimmun Medizinische Labordiagnostika AG (Germany): Anti-Measles Virus ELISA (IGM), Anti-Measles Virus ELISA (IgG); Avidity: Anti-Measles Virus ELISA (IgG), and also ELISA Vector-Best IgM-measles test system (Russia). Results and discussion. Only one out of 22 examined healthy individuals hasnt revealed IgG-antibodies to measles virus. The quantitative titre test of IgG-antibodies, and also their avidity among other 21 individuals testify experiencing measles in the recent or remote past. Having examined 116 blood serum samples of hospital patients in Kindi for IgM-measles-antibodies, the measles case with a 2.5-year-old child has been retrospectively revealed. Having examined 130 blood serum samples for IgG-antibodies to measles virus, 12.3% of seronegative to measles individuals have been revealed. All examined individuals aged 23 and older were seropositive to measles virus, and 60% of them had high antibody titres. The antibodies to measles virus were absent or were defined in low titres among 76.2% of people under 22, which can demonstrate violations of planned child vaccination due to the Ebola outbreak. In order to decrease the risk of emergence of large measles outbreaks in the areas, free from Ebola virus transmission, WHO recommends to conduct mass anti-measles vaccination campaigns.

Abstracts of the 34th International Congress of the International Society of Blood Transfusion, Dubai, United Arab Emirates, September 3-8, 2016.

Hepatitis E (HEV) has become the topic in transfusion medicine a few years ago since its occurence is increasing in developed countries. Therefore there is a risk of viral transmission by blood. Blood donors in Croatia are not routinely screened for HEV and there are no data regarding HEV seroprevalence in the general population. We also had no trace-back for HEV. Aims were to estimate the seroprevalence of HEV among voluntary blood donors (VBD) in the Croatian Institute of Transfusion Medicine (CITM). In October and November 2014 a total of 1036 serum samples of VBD were collected. All donors had previously completed the medical questionnaire to verify that they fulfilled the criteria for blood donation and had given informed consent. The study was approved by the Ethics Committee of CITM. There were 913 (88, 1%) males and 123 (11, 9%) females. All of the testing was done according to the producer’s instructions. Samples were primarily tested for total HEV antibodies using a commercial enzyme immunoassay, HEV Ab, Dia.Pro Srl, Milan, Italy (performed on Gemini analyzer). All reactive samples were tested for HEV IgG/IgM by comercial immunoassays, HEV IgG/IgM, Dia.Pro Srl, Milan, Italy (performed on Gemini analyzer). All HEV IgM reactive samples were confirmed by a comercial immunoblot assay, recomLine HEV IgM, Mikrogen, Neuried, Germany (performed on Dynablot Plus analyzer). IgM-positive samples were further tested for the presence of HEV RNA. Viral RNA extraction (QIAamp viral RNA Mini Kit®, Qiagen, Hilden, Germany) was performed from 140 µl of each sera sample. A real time RT-PCR protocol (Jothikumar et al., 2006) for detecting a highly conserved fragment within ORF3 was carried out. The amplification was done in a Rotor-Gene Q machine (Qiagen, Hilden, Germany) by the use of commercially available kits (Rotor-Gene Probe RT-PCR kit, Qiagen, Hilden, Germany) according to the producer’s instructions. 223/1036 (21, 5%) samples were reactive for total HEV antibodies. 210/223 were reactive for HEV IgG and overall anti-HEV IgG seroprevalence was 20, 3%. 45/223 samples were anti-HEV IgM reactive, 18/45 (1, 7%) were confirmed by immunoblot HEV IgM test and HEV RNA was not detected in any of those 18 samples. There is a significant association between age (less and more then 40) and a higher seroprevalence (P<0, 001). The difference between males and females was not significant (P=0, 807). Conclusion: We observed a high HEV IgG seroprevalence of 20, 3% among voluntary blood donors in comparison to the results of previous Croatian data (used Anti-hepatitis E virus ELISA test, Euroimun, Lubeck, Germany) for different population groups: alcohol abusers 8, 9%, war veterans 8, 6%, injecting drug users 6, 1% and healthcare professionals 2, 7%. Results suggest that most autochthonous HEV infections are either asymptomatic or unrecognized. The HEV seroprevalence studies done in developed countries show significant differences, from 0, 3% in Greece to 52, 5% in southwest France, depending on different HEV antibodies detection assays “Wenzel et al, The Journal of Infectious Diseases, 2013”. So, further study will be conducted that compare 3 different anti-HEV IgG/IgM tests.

First International Workshop on Zika Virus Held by Oswaldo Cruz Foundation FIOCRUZ in Northeast Brazil March 2016 - A Meeting Report.

First International Workshop on Zika Virus Held by Oswaldo Cruz Foundation FIOCRUZ in Northeast Brazil March 2016 - A Meeting Report.

High specificity of a novel Zika virus ELISA in European patients after exposure to different flaviviruses.

The current Zika virus (ZIKV) epidemic in the Americas caused an increase in diagnostic requests in European countries. Here we demonstrate high specificity of the Euroimmun anti-ZIKV IgG and IgM ELISA tests using putative cross-reacting sera of European patients with antibodies against tick-borne encephalitis virus, dengue virus, yellow fever virus and hepatitis C virus. This test may aid in counselling European travellers returning from regions where ZIKV is endemic.

Evolution of immunoassay with reference to HIV: brief review

Evolution of rapid test kit and development from first to fourth generation Human Immunodeficiency Virus (HIV) ELISA and CLIA have resulted in high automation, high through put as well as increased sensitivity and specificity. The window period of HIV has decreased whereas blood safety has increased significantly. Despite of all the progress made so far screening test detecting antigen and / or antibodies, although highly effective in identifying infected persons, will not always detect all individuals who are infected and do not correctly classify persons who are not infected. Different generation of ELISA kits have pros &amp; cons and can be used in different algorithm of HIV testing.

The first reported outbreak of equine herpesvirus myeloencephalopathy in New Zealand

CASE HISTORY AND CLINICAL FINDINGS: On 9 January 2014 (Day 0) a mare from a stud farm in the Waikato region presented with urinary incontinence without pyrexia. Over the following 33 days 15 mares were clinically affected with neurological signs. All but one mare had a foal at foot. The most commonly observed clinical signs were hind limb paresis and ataxia. In some cases recumbency occurred very early in the course of disease and seven mares were subject to euthanasia for humane reasons.LABORATORY FINDINGS: Equid herpesvirus (EHV) type 1 was detected using PCR in various tissues collected post mortem from two mares with neurological signs. DNA sequencing data from the DNA polymerase gene of the virus showed a nucleotide transition at position 2254, a mutation encoding amino acid D752 that is highly associated with the neuropathogenic genotype of EHV-1. In total 12/15 mares were confirmed positive for EHV-1 on PCR. Results from a virus neutralisation test and ELISA on paired serum samples, and PCR on whole blood and nasal swabs, indicated that of four paddocks in a high-risk area where a cluster of cases had occurred, 20/21 (95%) horses were likely to have been exposed or were confirmed infected with EHV-1. Subsequent to the outbreak two mares aborted, one at 9 months and one at 10 months of gestation. The cause of abortion was confirmed as EHV-1 with the same genotype as that involved in the outbreak.DIAGNOSIS: Equine herpesvirus myeloencephalopathy.CLINICAL RELEVANCE: The outbreak described shows the considerable impact that can occur in outbreaks of equine herpesvirus myeloencephalopathy in New Zealand. Early biosecurity controls not only reduced the effect on the farm but mitigated the potential for the virus to spread to other horse enterprises.

Persistence of the protective immunity and kinetics of the isotype specific antibody response against the viral nucleocapsid protein after experimental Schmallenberg virus infection of sheep.

Schmallenberg virus (SBV) is an Orthobunyavirus that induces abortion, stillbirths and congenital malformations in ruminants. SBV infection induces a long lasting seroconversion under natural conditions. The persistence of the protective immunity and the isotype specific antibody response upon SBV infection of sheep has however not been studied in detail. Five sheep were kept in BSL3 facilities for more than 16 months and subjected to repeated SBV infections. Blood was regularly sampled and organs were collected at euthanasia. The presence of SBV RNA in serum and organs was measured with quantitative real-time PCR. The appearance and persistence of neutralizing and SBV nucleoprotein (N) isotype specific antibodies was determined with virus neutralization tests (VNT) and ELISAs. The primo SBV infection protected ewes against clinical signs, viraemia and virus replication in organs upon challenge infections more than 15 months later. Production of neutralizing SBV specific antibodies was first detected around 6 days post primo-inoculation with VNT and correlated with the appearance of SBV-N specific IgM antibodies. These IgM antibodies remained present for 2 weeks. SBV-N specific IgG antibodies were first detected between 10 and 21 dpi and reached a plateau at 28 dpi. This plateau remained consistently high and no significant decrease in titre was found over a period of more than 1 year. Similar results were found for the neutralising antibody response. In conclusion, the SBV specific IgM response probably eliminates SBV from the blood and the protective immunity induced by SBV infection protects sheep against reinfection for at least 16 months.

Peptide microarray mapping of B cell epitopes on bovine leukemia virus and peptide ELISA analysis of conservation of epitopes in BLV infected Japanese cattle

The bovine leukemia virus (BLV), a retrovirus structurally and functionally related to the human T-lymphotropic viruses HTLV-1 and HTLV-2, is the etiological agent of bovine leucosis. B cell immune mechanisms may play a major role in protection against BLV infection. A battery of 157 synthetic peptides, 15-mer length, 4 amino acids overlapped, was used to mapping B cell epitopes on BLV envelope glycoprotein gp5l and capsid protein by peptide microarrays. Two susceptible cattle with the homozygote BoLA-DRB3 *1601 allele and two non-susceptible cattle with DRB3 *1501/*2703 alleles and DRB3 *1501/*0503 alleles were infected with BLV, and serums were collected from those cattle each of having challenged BLV before and after. Only one epitope A out of 157 synthetic peptides responds with all of four BLV positive serums not their negative serums. To demonstrate whether epitope A is common B cell epitope or not by our established peptide ELISA system that uses maleimide activated mariculture keyhole limpet hemocyanin (mcKLH) carrier protein. To found, there are 7 kinds of BLV positive serum no response with epitope A among 232 kinds of positive serum. Furthermore, we searched other peptides respond with BLV positive serum that contain 7 kinds of serum no responded with epitope A and found epitope B among peptides of non-specifically responded on peptide microarray. Epitope B strongly responded with all of 232 kinds of serum as estimated by peptide ELISA system. Our results shows that epitope B has a tendency to react some BLV negative serums, thus we will perform further experiments to determine the common B cell epitope just responses with positive serum by peptides that are 3 alanine substitutions as shifting one amino acid on epitope sequence.

Development of an AGID based on baculovirus expressed Pseudorabies virus glycoprotein B

Development of an AGID based on baculovirus expressed Pseudorabies virus glycoprotein B

Prevalence and Clinical Characteristics of Primary Epstein-Barr Virus Infection Among Children Presented with Cervical Lymphadenopathy.

Epstein-Barr virus is a known cause of childhood cervical lymphadenopathy. In practice this infection is not sought as a cause in low-resources settings. The virus among children with cervical lymphadenopathy was not studied before in this country. The aims of this study were to estimate the prevalence of primary EBV infection and to describe clinical characteristics of children presenting with cervical lymphadenopathy. A cross-sectional study was conducted among children presented with cervical lymphadenopathy to Khartoum Children Emergency Hospital during the period from February 2009 to January 2010. Eighty-two children were randomly selected. Demographic and clinical data were recorded. Routine laboratory values were determined and children's sera were analysed for anti- viral capsid antigens IgM Epstein-Barr virus ELISA tests. Mean and SD were calculated. Regression analysis was to identify association between demographic, clinical and laboratory variables and IgM seropositivity of EBV. Epstein-Barr virus infection was diagnosed in 13 (15.9%) children with cervical adenopathy (n=82). The average age of these children was 7.5 (SD±3.3) years. The male to female ratio was 1.6. The most frequent symptoms were fever, loss of appetite and cough. The anterior cervical group of lymph nodes was most commonly implicated. All affected patients had mobile lymph nodes and the majority, 12 (92.3%), of patient had firm nodes. The lymph node number ranged from 2-6 nodes; with a mean of 3.5 nodes and average size of 3.6 cm. Splenomegaly and pharyngo-tonsillitis were found in 30.8% and 23.1% of patients respectively and leukocytosis was noted in 3 (23.1%). The odds of IgM seropositivity decreased with age ≤ 9 years (OR 0.15, 95% CI 0.03-0.78, p=0.023). EBV infection is not an uncommon cause of childhood cervical lymphadenopathy. The commonest symptoms are fever, loss of appetite and cough. Anterior cervical nodes are the most affected. Younger children (age ≤ 9 years) are less likely to be sero-positive.

Serological diagnosis of hantavirus pulmonary syndrome in a febrile patient in Colombia

Hantavirus pulmonary syndrome (HPS) is an often fatal rodent-borne zoonosis caused by any of at least 20 hantavirus genotypes distributed throughout the Americas. Although HPS has been documented in several bordering countries, it has not been reported in Colombia. Here we report seroconversion to a hantavirus in paired samples from a hospitalized patient with symptoms compatible with HPS from Montería, Córdoba Department, north-western Colombia. Tests for regionally endemic agents including Plasmodium, Leptospira, Salmonella, dengue virus, Brucella, Rickettsia, human immunodeficiency virus and hepatitis viruses were negative. Because the patient was enrolled in a clinical trial for hemorrhagic fevers conducted by the University of Córdoba, serum samples were collected on admission and at discharge. Testing using Sin Nombre virus ELISA showed IgG and IgM seroconversion between samples. The eventual finding of this first clinical case of hantavirus infection in Colombia is consistent with the high prevalence of hantavirus antibodies in humans in the region and the likely exposure of the patient to rodents. The clinical presentation was similar to that found in neighbouring Panama.

Application Of Recent Methods For Diagnosis Of Foot And Mouth Disease In Cattle And Buffaloes

Egypt was recently exposed to a sever outbreak of Foot and Mouth Disease (FMD) in 2012 with a new introduced strain of the virus (SAT2). This study concerned with diagnosis of FMD by using some recent methods in addition to the traditional methods of diagnosis. A total of 326 animals were clinically examined in different localities at Sharkia Governorates; 301 animals showed clinical signs of FMD (diseased animals) and 25 animals were apparently healthy. The diseased animals consisted of 277 cattle and 24 buffaloes. Some of them were vaccinated with the FMD bivalent vaccine before the outbreak and others were not vaccinated. Eighty two clinical samples (73 epithelial tissues (Epi.T.) and 9 vesicular fluids (V.F)) from cattle and buffaloes were isolated on Baby Hamster kidney (BHK-21) cell line and 76 samples (92.7%) were positive. By using FMDV ELISA Kits for typing the virus only serotype SAT2 was detected. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect SAT2 serotype in 10 sample collected from 5 diseased cattle and 5 diseased buffaloes from different localities. Only one sample showed negative reaction (this sample was also negative by virus isolation and ELISA typing). Serum samples were collected from the 301 animals at different times after the infection; the antibodies against FMDV non-structural protein were detected by FMDV′CHEK Test in 270 cases (89.7%) of examined animals, while antibodies against the structural protein were detected by SNT and ELISA where antibodies against serotypes O, A and SAT2 were detected in 75.7%, 75.7% and 100% of examined animals for each serotype respectively by both tests. Mixed infection with more than one serotype was only recorded at Al-Salhia dairy farm. It is concluded that combination between recent and traditional techniques for diagnosis of FMD help in accurate and rabid diagnosis and subsequently control the disease.