The West Africa Ebola virus disease (EVD) outbreak has reached unprecedented magnitude and caused... more The West Africa Ebola virus disease (EVD) outbreak has reached unprecedented magnitude and caused worldwide concerns for the spread of this deadly virus. Recent findings in nonhuman primates (NHPs) demonstrate that antibodies can be protective against EVD. However, the role of antibody response in vaccine-mediated protection is not fully understood. To address these questions quantitative serology assays are needed for measurement of the antibody response to key Ebola virus (EBOV) proteins. Serology enzyme-linked immunosorbent assays (ELISA's), using a reference detection antibody, were developed in order to standardize the quantitation of antibody levels in vaccinated NHPs or in humans exposed to EBOV or immunized with an EBOV vaccine. Critical reagents were generated to support the development of the serology ELISAs. Recombinant EBOV matrix protein (VP40) was expressed in E. coli and purified. Two variants of the glycoprotein (GP), the ectodomain lacking the transmembrane doma...
The recently developed Xpert® Ebola Assay is a novel nucleic acid amplification test for simplifi... more The recently developed Xpert® Ebola Assay is a novel nucleic acid amplification test for simplified detection of Ebola virus (EBOV) in whole blood and buccal swab samples. The assay targets sequences in two EBOV genes, lowering the risk for new variants to escape detection in the test. The objective of this report is to present analytical characteristics of the Xpert® Ebola Assay on whole blood samples. This study evaluated the assay's analytical sensitivity, analytical specificity, inclusivity and exclusivity performance in whole blood specimens. EBOV RNA, inactivated EBOV, and infectious EBOV were used as targets. The dynamic range of the assay, the inactivation of virus, and specimen stability were also evaluated. The lower limit of detection (LoD) for the assay using inactivated virus was estimated to be 73 copies/mL (95% CI: 51-97 copies/mL). The LoD for infectious virus was estimated to be 1 plaque-forming unit/mL, and for RNA to be 232 copies/mL (95% CI 163-302 copies/mL). The assay correctly identified five different Ebola viruses, Yambuku-Mayinga, Makona-C07, Yambuku-Ecran, Gabon-Ilembe, and Kikwit-956210, and correctly excluded all non-EBOV isolates tested. The conditions used by Xpert® Ebola for inactivation of infectious virus reduced EBOV titer by ≥6 logs. In summary, we found the Xpert® Ebola Assay to have high analytical sensitivity and specificity for the detection of EBOV in whole blood. It offers ease of use, fast turnaround time, and remote monitoring. The test has an efficient viral inactivation protocol, fulfills inclusivity and exclusivity criteria, and has specimen stability characteristics consistent with the need for decentralized testing. The simplicity of the assay should enable testing in a wide variety of laboratory settings, including remote laboratories that are not capable of performing highly complex nucleic acid amplification tests, and during outbreaks where time to detection is critical.
Ebola virus (EBOV) causes periodic outbreaks of life-threatening EBOV disease in Africa. Historic... more Ebola virus (EBOV) causes periodic outbreaks of life-threatening EBOV disease in Africa. Historically, these outbreaks have been relatively small and geographically contained; however, the magnitude of the EBOV outbreak that began in 2014 in West Africa has been unprecedented. The aim of this study was to describe the viral kinetics of EBOV during this outbreak and identify factors that contribute to outbreak progression. From July to December 2014, one laboratory in Sierra Leone processed over 2,700 patient samples for EBOV detection by quantitative PCR (qPCR). Viremia was measured following patient admission. Age, sex, and approximate time of symptom onset were also recorded for each patient. The data was analyzed using various mathematical models to find trends of potential interest. The analysis revealed a significant difference (P = 2.7 × 10-77) between the initial viremia of survivors (4.02 log10 genome equivalents [GEQ]/ml) and nonsurvivors (6.18 log10 GEQ/ml). At the population level, patient viral loads were higher on average in July than in November, even when accounting for outcome and time since onset of symptoms. This decrease in viral loads temporally correlated with an increase in circulating EBOV-specific IgG antibodies among individuals who were suspected of being infected but shown to be negative for the virus by PCR. Our results indicate that initial viremia is associated with outcome of the individual and outbreak duration; therefore, care must be taken in planning clinical trials and interventions. Additional research in virus adaptation and the impacts of host factors on EBOV transmission and pathogenesis is needed.
cDNAs for ovine surfactant-associated protein (SP) A, SP-B, and SP-C have been cloned and shown t... more cDNAs for ovine surfactant-associated protein (SP) A, SP-B, and SP-C have been cloned and shown to possess strong similarity to cDNAs for surfactant apoproteins in other species. These reagents were employed to examine the effect of fetal hypoxia on the induction of surfactant apoprotein expression in the fetal lamb. Postnatal lung function is dependent on adequate growth and maturation during fetal development. Insulin-like growth factor (IGF) I and IGF-II, which are present in all fetal tissues studied, possess potent mitogenic and proliferative actions, and their effects can be modulated by IGF-specific binding proteins (IGFBPs). Hypoxia can lead to increases in circulating cortisol and catecholamines that can influence lung maturation. Therefore, the effects of mild hypoxia in chronically catheterized fetal lambs at gestational days 126-130 and 134-136 (term 145 days) on the expression of pulmonary surfactant apoproteins and IGFBPs were examined. Mild hypoxia for 48 h resulted in an increase in plasma cortisol that was more pronounced at later gestation, and in these animals, there was a twofold increase in SP-A mRNA. SP-B mRNA levels also increased twofold, but this was not significant. SP-C mRNA was not altered. No significant changes in apoprotein mRNA were observed with the younger fetuses. However, these younger animals selectively exhibited reduced IGFBP-5 mRNA levels. IGF-I mRNA was also reduced at 126-130 days, although this conclusion is tentative due to low abundance. IGF-II levels were not affected at either gestational age. We conclude that these data suggest that mild prolonged fetal hypoxia produces alterations that could affect fetal cellular differentiation early in gestation and can induce changes consistent with lung maturation closer to term.
The American journal of tropical medicine and hygiene, 2007
In May 2005, a cluster of four hantavirus pulmonary syndrome (HPS) cases was confirmed in Alberta... more In May 2005, a cluster of four hantavirus pulmonary syndrome (HPS) cases was confirmed in Alberta, Canada. The cluster is unusual given that three cases were from a single family and involved a 7-year-old child. This is the first family cluster reported in Canada and includes one of the youngest cases of HPS reported in North America.
Available evidence demonstrates that direct patient contact and contact with infectious body flui... more Available evidence demonstrates that direct patient contact and contact with infectious body fluids are the primary modes for Ebola virus transmission, but this is based on a limited number of studies. Key areas requiring further study include (i) the role of aerosol transmission (either via large droplets or small particles in the vicinity of source patients), (ii) the role of environmental contamination and fomite transmission, (iii) the degree to which minimally or mildly ill persons transmit infection, (iv) how long clinically relevant infectiousness persists, (v) the role that "superspreading events" may play in driving transmission dynamics, (vi) whether strain differences or repeated serial passage in outbreak settings can impact virus transmission, and (vii) what role sylvatic or domestic animals could play in outbreak propagation, particularly during major epidemics such as the 2013-2015 West Africa situation. In this review, we address what we know and what we do not know about Ebola virus transmission. We also hypothesize that Ebola viruses have the potential to be respiratory pathogens with primary respiratory spread.
CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, Jan 6, 2004
An outbreak of severe acute respiratory syndrome (SARS) began in Canada in February 2003. The ini... more An outbreak of severe acute respiratory syndrome (SARS) began in Canada in February 2003. The initial diagnosis of SARS was based on clinical and epidemiological criteria. During the outbreak, molecular and serologic tests for the SARS-associated coronavirus (SARS-CoV) became available. However, without a "gold standard," it was impossible to determine the usefulness of these tests. We describe how these tests were used during the first phase of the SARS outbreak in Toronto and offer some recommendations that may be useful if SARS returns. We examined the results of all diagnostic laboratory tests used in 117 patients admitted to hospitals in Toronto who met the Health Canada criteria for suspect or probable SARS. Focusing on tests for SARS-CoV, we attempted to determine the optimal specimen types and timing of specimen collection. Diagnostic test results for SARS-CoV were available for 110 of the 117 patients. SARS-CoV was detected by means of reverse-transcriptase polyme...
Squirrel monkey (Saimiri sciureus) corticosteroid-binding globulin (CBG) is the product of a 1.6-... more Squirrel monkey (Saimiri sciureus) corticosteroid-binding globulin (CBG) is the product of a 1.6-kilobase mRNA in the liver. Analyses of two overlapping cDNAs revealed that the squirrel monkey CBG precursor comprises 406 amino acids, the first 22 residues of which exhibit 91% identity with the human CBG leader sequence. The mature form of squirrel monkey CBG, therefore, very likely comprises 384 amino acids and has a polypeptide mol wt of 42,854. Compared to human CBG, the squirrel monkey protein contains an additional residue (threonine) at position 144, and the two proteins exhibit 86% sequence identity if this is taken into account. Squirrel monkey CBG contains five consensus sites for N-glycosylation, four of which are located in analogous positions in human CBG, and has two cysteine residues in the same relative positions as the cysteines in human CBG. Unlike CBG in most other species, squirrel monkey CBG appears to circulate as a dimer, and its affinity for glucocorticoids is remarkably low. We, therefore, expressed cDNAs for human and squirrel monkey CBGs in Chinese hamster ovary (CHO) cells and compared the physico-chemical properties of the products with those of the corresponding serum proteins. Squirrel monkey CBG is produced by CHO cells as a dimer, and its subunit size heterogeneity is similar to that associated with CBG in serum. In addition, the cortisol-binding affinity of squirrel monkey CBG produced by CHO cells is similar to that of the natural protein and is 5- to 8-fold lower than that of natural or recombinant human CBG. Mutants in which a threonine at position 144 was either added to human CBG or subtracted from squirrel monkey CBG were also expressed in CHO cells. This demonstrated that this additional amino acid in the squirrel monkey CBG sequence may actively contribute to its propensity for spontaneous dimerization, but does not account for its relatively low steroid-binding affinity.
A number of "new" infections are emerging in our midst and the ... more A number of "new" infections are emerging in our midst and the medical practitioners should be aware of these. Suspected cases should be urgently investigated and treated to prevent further spread.
Malaria is a major public health concern in the countries affected by the Ebola virus disease epi... more Malaria is a major public health concern in the countries affected by the Ebola virus disease epidemic in West Africa. We determined the feasibility of using molecular malaria diagnostics during an Ebola virus disease outbreak and report the incidence of Plasmodium spp. parasitemia in persons with suspected Ebola virus infection.
Vaccines and therapies are urgently needed to address public health needs stemming from emerging ... more Vaccines and therapies are urgently needed to address public health needs stemming from emerging pathogens and biological threat agents such as the filoviruses Ebola virus (EBOV) and Marburg virus (MARV). Here, we developed replication-competent vaccines against EBOV and MARV based on attenuated recombinant vesicular stomatitis virus vectors expressing either the EBOV glycoprotein or MARV glycoprotein. A single intramuscular injection of the EBOV or MARV vaccine elicited completely protective immune responses in nonhuman primates against lethal EBOV or MARV challenges. Notably, vaccine vector shedding was not detectable in the monkeys and none of the animals developed fever or other symptoms of illness associated with vaccination. The EBOV vaccine induced humoral and apparent cellular immune responses in all vaccinated monkeys, whereas the MARV vaccine induced a stronger humoral than cellular immune response. No evidence of EBOV or MARV replication was detected in any of the protected animals after challenge. Our data suggest that these vaccine candidates are safe and highly efficacious in a relevant animal model.
The control of Filovirus outbreaks can be greatly enhanced by timely laboratory confirmation of i... more The control of Filovirus outbreaks can be greatly enhanced by timely laboratory confirmation of infection or the identification of alternative disease processes. The status of current laboratory diagnostics for Ebola and Marburg virus infections is discussed in terms of the assays available and their interpretation. In addition, the role of field-based laboratory support and its limitations and capabilities in an outbreak response setting, especially in regards to real-time PCR and immunofiltration assays, is presented.
Background: CCHF virus belongs to the family Bunyaviridae. Virus causes severe haemorrhagic sympt... more Background: CCHF virus belongs to the family Bunyaviridae. Virus causes severe haemorrhagic symptoms in man and humans are infected with CCHF virus either through the bite of infected ticks or by direct contact with virus contaminated tissues or blood.Methods: From June 2000 to 4 March 2007, sera from 898 CCHF suspected human cases were analyzed serologically by ELISA method for detecting of IgM and IgG andmolecularly by RT-PCR method for detecting of presence of a fragment in the S segment of the virus genome. Results: Among 898 suspected patients, 348 (311 were IgM (+) and 37 were RT-PCR(+)) were confirmed cases. Between 898 suspected cases, 445 were checked with RT-PCR and 83 were RT-PCR (+), IgM (+) and 37 were RT-PCR (+), IgM(-) (24 cases died fulminantly and from 13 patients we had only one serum sample). Sistan-Baluchestan province was the most infected province. The majority professions of the confirmed cases were: farmer (19.1%), worker (18.9%), housewife (18.7%), butcher (...
The West Africa Ebola virus disease (EVD) outbreak has reached unprecedented magnitude and caused... more The West Africa Ebola virus disease (EVD) outbreak has reached unprecedented magnitude and caused worldwide concerns for the spread of this deadly virus. Recent findings in nonhuman primates (NHPs) demonstrate that antibodies can be protective against EVD. However, the role of antibody response in vaccine-mediated protection is not fully understood. To address these questions quantitative serology assays are needed for measurement of the antibody response to key Ebola virus (EBOV) proteins. Serology enzyme-linked immunosorbent assays (ELISA's), using a reference detection antibody, were developed in order to standardize the quantitation of antibody levels in vaccinated NHPs or in humans exposed to EBOV or immunized with an EBOV vaccine. Critical reagents were generated to support the development of the serology ELISAs. Recombinant EBOV matrix protein (VP40) was expressed in E. coli and purified. Two variants of the glycoprotein (GP), the ectodomain lacking the transmembrane doma...
The recently developed Xpert® Ebola Assay is a novel nucleic acid amplification test for simplifi... more The recently developed Xpert® Ebola Assay is a novel nucleic acid amplification test for simplified detection of Ebola virus (EBOV) in whole blood and buccal swab samples. The assay targets sequences in two EBOV genes, lowering the risk for new variants to escape detection in the test. The objective of this report is to present analytical characteristics of the Xpert® Ebola Assay on whole blood samples. This study evaluated the assay's analytical sensitivity, analytical specificity, inclusivity and exclusivity performance in whole blood specimens. EBOV RNA, inactivated EBOV, and infectious EBOV were used as targets. The dynamic range of the assay, the inactivation of virus, and specimen stability were also evaluated. The lower limit of detection (LoD) for the assay using inactivated virus was estimated to be 73 copies/mL (95% CI: 51-97 copies/mL). The LoD for infectious virus was estimated to be 1 plaque-forming unit/mL, and for RNA to be 232 copies/mL (95% CI 163-302 copies/mL). The assay correctly identified five different Ebola viruses, Yambuku-Mayinga, Makona-C07, Yambuku-Ecran, Gabon-Ilembe, and Kikwit-956210, and correctly excluded all non-EBOV isolates tested. The conditions used by Xpert® Ebola for inactivation of infectious virus reduced EBOV titer by ≥6 logs. In summary, we found the Xpert® Ebola Assay to have high analytical sensitivity and specificity for the detection of EBOV in whole blood. It offers ease of use, fast turnaround time, and remote monitoring. The test has an efficient viral inactivation protocol, fulfills inclusivity and exclusivity criteria, and has specimen stability characteristics consistent with the need for decentralized testing. The simplicity of the assay should enable testing in a wide variety of laboratory settings, including remote laboratories that are not capable of performing highly complex nucleic acid amplification tests, and during outbreaks where time to detection is critical.
Ebola virus (EBOV) causes periodic outbreaks of life-threatening EBOV disease in Africa. Historic... more Ebola virus (EBOV) causes periodic outbreaks of life-threatening EBOV disease in Africa. Historically, these outbreaks have been relatively small and geographically contained; however, the magnitude of the EBOV outbreak that began in 2014 in West Africa has been unprecedented. The aim of this study was to describe the viral kinetics of EBOV during this outbreak and identify factors that contribute to outbreak progression. From July to December 2014, one laboratory in Sierra Leone processed over 2,700 patient samples for EBOV detection by quantitative PCR (qPCR). Viremia was measured following patient admission. Age, sex, and approximate time of symptom onset were also recorded for each patient. The data was analyzed using various mathematical models to find trends of potential interest. The analysis revealed a significant difference (P = 2.7 × 10-77) between the initial viremia of survivors (4.02 log10 genome equivalents [GEQ]/ml) and nonsurvivors (6.18 log10 GEQ/ml). At the population level, patient viral loads were higher on average in July than in November, even when accounting for outcome and time since onset of symptoms. This decrease in viral loads temporally correlated with an increase in circulating EBOV-specific IgG antibodies among individuals who were suspected of being infected but shown to be negative for the virus by PCR. Our results indicate that initial viremia is associated with outcome of the individual and outbreak duration; therefore, care must be taken in planning clinical trials and interventions. Additional research in virus adaptation and the impacts of host factors on EBOV transmission and pathogenesis is needed.
cDNAs for ovine surfactant-associated protein (SP) A, SP-B, and SP-C have been cloned and shown t... more cDNAs for ovine surfactant-associated protein (SP) A, SP-B, and SP-C have been cloned and shown to possess strong similarity to cDNAs for surfactant apoproteins in other species. These reagents were employed to examine the effect of fetal hypoxia on the induction of surfactant apoprotein expression in the fetal lamb. Postnatal lung function is dependent on adequate growth and maturation during fetal development. Insulin-like growth factor (IGF) I and IGF-II, which are present in all fetal tissues studied, possess potent mitogenic and proliferative actions, and their effects can be modulated by IGF-specific binding proteins (IGFBPs). Hypoxia can lead to increases in circulating cortisol and catecholamines that can influence lung maturation. Therefore, the effects of mild hypoxia in chronically catheterized fetal lambs at gestational days 126-130 and 134-136 (term 145 days) on the expression of pulmonary surfactant apoproteins and IGFBPs were examined. Mild hypoxia for 48 h resulted in an increase in plasma cortisol that was more pronounced at later gestation, and in these animals, there was a twofold increase in SP-A mRNA. SP-B mRNA levels also increased twofold, but this was not significant. SP-C mRNA was not altered. No significant changes in apoprotein mRNA were observed with the younger fetuses. However, these younger animals selectively exhibited reduced IGFBP-5 mRNA levels. IGF-I mRNA was also reduced at 126-130 days, although this conclusion is tentative due to low abundance. IGF-II levels were not affected at either gestational age. We conclude that these data suggest that mild prolonged fetal hypoxia produces alterations that could affect fetal cellular differentiation early in gestation and can induce changes consistent with lung maturation closer to term.
The American journal of tropical medicine and hygiene, 2007
In May 2005, a cluster of four hantavirus pulmonary syndrome (HPS) cases was confirmed in Alberta... more In May 2005, a cluster of four hantavirus pulmonary syndrome (HPS) cases was confirmed in Alberta, Canada. The cluster is unusual given that three cases were from a single family and involved a 7-year-old child. This is the first family cluster reported in Canada and includes one of the youngest cases of HPS reported in North America.
Available evidence demonstrates that direct patient contact and contact with infectious body flui... more Available evidence demonstrates that direct patient contact and contact with infectious body fluids are the primary modes for Ebola virus transmission, but this is based on a limited number of studies. Key areas requiring further study include (i) the role of aerosol transmission (either via large droplets or small particles in the vicinity of source patients), (ii) the role of environmental contamination and fomite transmission, (iii) the degree to which minimally or mildly ill persons transmit infection, (iv) how long clinically relevant infectiousness persists, (v) the role that "superspreading events" may play in driving transmission dynamics, (vi) whether strain differences or repeated serial passage in outbreak settings can impact virus transmission, and (vii) what role sylvatic or domestic animals could play in outbreak propagation, particularly during major epidemics such as the 2013-2015 West Africa situation. In this review, we address what we know and what we do not know about Ebola virus transmission. We also hypothesize that Ebola viruses have the potential to be respiratory pathogens with primary respiratory spread.
CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, Jan 6, 2004
An outbreak of severe acute respiratory syndrome (SARS) began in Canada in February 2003. The ini... more An outbreak of severe acute respiratory syndrome (SARS) began in Canada in February 2003. The initial diagnosis of SARS was based on clinical and epidemiological criteria. During the outbreak, molecular and serologic tests for the SARS-associated coronavirus (SARS-CoV) became available. However, without a "gold standard," it was impossible to determine the usefulness of these tests. We describe how these tests were used during the first phase of the SARS outbreak in Toronto and offer some recommendations that may be useful if SARS returns. We examined the results of all diagnostic laboratory tests used in 117 patients admitted to hospitals in Toronto who met the Health Canada criteria for suspect or probable SARS. Focusing on tests for SARS-CoV, we attempted to determine the optimal specimen types and timing of specimen collection. Diagnostic test results for SARS-CoV were available for 110 of the 117 patients. SARS-CoV was detected by means of reverse-transcriptase polyme...
Squirrel monkey (Saimiri sciureus) corticosteroid-binding globulin (CBG) is the product of a 1.6-... more Squirrel monkey (Saimiri sciureus) corticosteroid-binding globulin (CBG) is the product of a 1.6-kilobase mRNA in the liver. Analyses of two overlapping cDNAs revealed that the squirrel monkey CBG precursor comprises 406 amino acids, the first 22 residues of which exhibit 91% identity with the human CBG leader sequence. The mature form of squirrel monkey CBG, therefore, very likely comprises 384 amino acids and has a polypeptide mol wt of 42,854. Compared to human CBG, the squirrel monkey protein contains an additional residue (threonine) at position 144, and the two proteins exhibit 86% sequence identity if this is taken into account. Squirrel monkey CBG contains five consensus sites for N-glycosylation, four of which are located in analogous positions in human CBG, and has two cysteine residues in the same relative positions as the cysteines in human CBG. Unlike CBG in most other species, squirrel monkey CBG appears to circulate as a dimer, and its affinity for glucocorticoids is remarkably low. We, therefore, expressed cDNAs for human and squirrel monkey CBGs in Chinese hamster ovary (CHO) cells and compared the physico-chemical properties of the products with those of the corresponding serum proteins. Squirrel monkey CBG is produced by CHO cells as a dimer, and its subunit size heterogeneity is similar to that associated with CBG in serum. In addition, the cortisol-binding affinity of squirrel monkey CBG produced by CHO cells is similar to that of the natural protein and is 5- to 8-fold lower than that of natural or recombinant human CBG. Mutants in which a threonine at position 144 was either added to human CBG or subtracted from squirrel monkey CBG were also expressed in CHO cells. This demonstrated that this additional amino acid in the squirrel monkey CBG sequence may actively contribute to its propensity for spontaneous dimerization, but does not account for its relatively low steroid-binding affinity.
A number of "new" infections are emerging in our midst and the ... more A number of "new" infections are emerging in our midst and the medical practitioners should be aware of these. Suspected cases should be urgently investigated and treated to prevent further spread.
Malaria is a major public health concern in the countries affected by the Ebola virus disease epi... more Malaria is a major public health concern in the countries affected by the Ebola virus disease epidemic in West Africa. We determined the feasibility of using molecular malaria diagnostics during an Ebola virus disease outbreak and report the incidence of Plasmodium spp. parasitemia in persons with suspected Ebola virus infection.
Vaccines and therapies are urgently needed to address public health needs stemming from emerging ... more Vaccines and therapies are urgently needed to address public health needs stemming from emerging pathogens and biological threat agents such as the filoviruses Ebola virus (EBOV) and Marburg virus (MARV). Here, we developed replication-competent vaccines against EBOV and MARV based on attenuated recombinant vesicular stomatitis virus vectors expressing either the EBOV glycoprotein or MARV glycoprotein. A single intramuscular injection of the EBOV or MARV vaccine elicited completely protective immune responses in nonhuman primates against lethal EBOV or MARV challenges. Notably, vaccine vector shedding was not detectable in the monkeys and none of the animals developed fever or other symptoms of illness associated with vaccination. The EBOV vaccine induced humoral and apparent cellular immune responses in all vaccinated monkeys, whereas the MARV vaccine induced a stronger humoral than cellular immune response. No evidence of EBOV or MARV replication was detected in any of the protected animals after challenge. Our data suggest that these vaccine candidates are safe and highly efficacious in a relevant animal model.
The control of Filovirus outbreaks can be greatly enhanced by timely laboratory confirmation of i... more The control of Filovirus outbreaks can be greatly enhanced by timely laboratory confirmation of infection or the identification of alternative disease processes. The status of current laboratory diagnostics for Ebola and Marburg virus infections is discussed in terms of the assays available and their interpretation. In addition, the role of field-based laboratory support and its limitations and capabilities in an outbreak response setting, especially in regards to real-time PCR and immunofiltration assays, is presented.
Background: CCHF virus belongs to the family Bunyaviridae. Virus causes severe haemorrhagic sympt... more Background: CCHF virus belongs to the family Bunyaviridae. Virus causes severe haemorrhagic symptoms in man and humans are infected with CCHF virus either through the bite of infected ticks or by direct contact with virus contaminated tissues or blood.Methods: From June 2000 to 4 March 2007, sera from 898 CCHF suspected human cases were analyzed serologically by ELISA method for detecting of IgM and IgG andmolecularly by RT-PCR method for detecting of presence of a fragment in the S segment of the virus genome. Results: Among 898 suspected patients, 348 (311 were IgM (+) and 37 were RT-PCR(+)) were confirmed cases. Between 898 suspected cases, 445 were checked with RT-PCR and 83 were RT-PCR (+), IgM (+) and 37 were RT-PCR (+), IgM(-) (24 cases died fulminantly and from 13 patients we had only one serum sample). Sistan-Baluchestan province was the most infected province. The majority professions of the confirmed cases were: farmer (19.1%), worker (18.9%), housewife (18.7%), butcher (...
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