Last data update: Nov 04, 2024. (Total: 48056 publications since 2009)
Records 1-30 (of 44 Records) |
Query Trace: Olson VA[original query] |
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Successful collaborations that resulted in increased U.S. diagnostic testing during the 2022 Mpox outbreak
Hutson CL , Villanueva J , Stenzel T , Olson VA , Gerald N , McNall R , Courtney S , Aden T , Rager S , Egan C , Blevins P , Kuhnert W , Davidson W , Khan T , Baird N , Kling C , Van Meter S , Chaitram J , Salerno RM . J Public Health Manag Pract 2024 CONTEXT: The first case of mpox was detected in the United States in a Laboratory Response Network (LRN) laboratory at the Massachusetts Department of Public Health on May 17, 2022. Through previous years of smallpox preparedness efforts by the United States government, testing capacity in LRN laboratories across the United States utilizing the FDA-cleared Centers for Disease Control and Prevention (CDC) Non-variola orthopoxvirus (NVO) test was approximately 6000 tests weekly across the nation prior to the mpox outbreak. By early June 2022, the LRN laboratories had capacity to perform up to 8000 tests per week. As the outbreak expanded, cases were identified in every United States state, peaking at ~3000 cases per week nationally in August 2022. OBJECTIVE: Although NVO testing capacity in LRN laboratories exceeded national mpox testing demand overall, LRN testing access in some areas was challenged and test expansion was necessary. PARTICIPANTS: CDC engaged with partners and select commercial laboratories early to increase diagnostic testing access by allowing these commercial laboratories to utilize the NVO test. SETTING: The expansion of testing to commercial laboratories increased testing availability, capacity, and volume nationwide. This was the first time that CDC shared an FDA 510k-cleared molecular test with commercial laboratories to support a public health emergency. DESIGN: Extensive efforts were made to ensure the CDC NVO test was used appropriately in the private sector and that the transfer process met regulatory requirements. MAIN OUTCOME MEASURES, RESULTS, CONCLUSIONS: These novel methods to expand NVO testing to commercial laboratories increased national testing capacity to 80 000 mpox tests/week. Test volumes among these laboratories never exceeded this expanded capacity. The rapid increase in the nation's testing capacity, in conjunction and coordination with other public and private health efforts, helped to detect cases rapidly. These actions demonstrated the importance of highly functional and efficient public health and private sector partnerships for responding to public health emergencies. |
Variola virus and clade I monkeypox virus differentially modulate cellular responses longitudinally in monocytes during infection
Wahl V , Olson VA , Kondas AV , Jahrling PB , Damon IK , Kindrachuk J . J Infect Dis 2024 229 S265-s274 Variola virus (VARV), the etiological agent of smallpox, had enormous impacts on global health prior to its eradication. In the absence of global vaccination programs, mpox virus (MPXV) has become a growing public health threat that includes endemic and nonendemic regions across the globe. While human mpox resembles smallpox in clinical presentation, there are considerable knowledge gaps regarding conserved molecular pathogenesis between these 2 orthopoxviruses. Thus, we sought to compare MPXV and VARV infections in human monocytes through kinome analysis. We performed a longitudinal analysis of host cellular responses to VARV infection in human monocytes as well as a comparative analysis to clade I MPXV-mediated responses. While both viruses elicited strong activation of cell responses early during infection as compared to later time points, several key differences in cell signaling events were identified and validated. These observations will help in the design and development of panorthopoxvirus therapeutics. |
Identification of small molecules with improved potency against orthopoxviruses from vaccinia to smallpox
Brown LE , Seitz S , Kondas AV , Marcyk PT , Filone CM , Hossain MM , Schaus SE , Olson VA , Connor JH . Antimicrob Agents Chemother 2022 66 (11) e0084122 The genus Orthopoxvirus contains several human pathogens, including vaccinia, monkeypox, cowpox, and variola virus, the causative agent of smallpox. Although there are a few effective vaccines, widespread prophylactic vaccination has ceased and is unlikely to resume, making therapeutics increasingly important to treat poxvirus disease. Here, we described efforts to improve the potency of the anti-poxvirus small molecule CMLDBU6128. This class of small molecules, referred to as pyridopyrimidinones (PDPMs), showed a wide range of biological activities. Through the synthesis and testing of several exploratory chemical libraries based on this molecule, we identified several compounds that had increased potency from the micromolar into the nanomolar range. Two compounds, designated (12) and (16), showed inhibitory concentrations of 326 nM and 101 nM, respectively, which was more than a 10-fold increase in potency to CMLDBU6128 with an inhibitory concentration of around 6 μM. We also expanded our investigation of the breadth of action of these molecules and showed that they can inhibit the replication of variola virus, a related orthopoxvirus. Together, these findings highlighted the promise of this new class of antipoxviral agents as broad-spectrum small molecules with significant potential to be developed as antiviral therapy. This would add a small molecule option for therapy of spreading diseases, including monkeypox and cowpox viruses, that would also be expected to have efficacy against smallpox. |
Teaching a new mouse old tricks: Humanized mice as an infection model for Variola virus
Hutson CL , Kondas AV , Ritter JM , Reed Z , Ostergaard SD , Morgan CN , Gallardo-Romero N , Tansey C , Mauldin MR , Salzer JS , Hughes CM , Goldsmith CS , Carroll D , Olson VA . PLoS Pathog 2021 17 (9) e1009633 Smallpox, caused by the solely human pathogen Variola virus (VARV), was declared eradicated in 1980. While known VARV stocks are secure, smallpox remains a bioterrorist threat agent. Recent U.S. Food and Drug Administration approval of the first smallpox anti-viral (tecovirimat) therapeutic was a successful step forward in smallpox preparedness; however, orthopoxviruses can become resistant to treatment, suggesting a multi-therapeutic approach is necessary. Animal models are required for testing medical countermeasures (MCMs) and ideally MCMs are tested directly against the pathogen of interest. Since VARV only infects humans, a representative animal model for testing therapeutics directly against VARV remains a challenge. Here we show that three different humanized mice strains are highly susceptible to VARV infection, establishing the first small animal model using VARV. In comparison, the non-humanized, immunosuppressed background mouse was not susceptible to systemic VARV infection. Following an intranasal VARV challenge that mimics the natural route for human smallpox transmission, the virus spread systemically within the humanized mouse before mortality (~ 13 days post infection), similar to the time from exposure to symptom onset for ordinary human smallpox. Our identification of a permissive/representative VARV animal model can facilitate testing of MCMs in a manner consistent with their intended use. |
Pharmacokinetics and efficacy of a potential smallpox therapeutic, brincidofovir, in a lethal monkeypox virus animal model
Hutson CL , Kondas AV , Mauldin MR , Doty JB , Grossi IM , Morgan CN , Ostergaard SD , Hughes CM , Nakazawa Y , Kling C , Martin BE , Ellison JA , Carroll DD , Gallardo-Romero NF , Olson VA . mSphere 2021 6 (1) Smallpox, caused by Variola virus (VARV), was eradicated in 1980; however, VARV bioterrorist threats still exist, necessitating readily available therapeutics. Current preparedness activities recognize the importance of oral antivirals and recommend therapeutics with different mechanisms of action. Monkeypox virus (MPXV) is closely related to VARV, causing a highly similar clinical human disease, and can be used as a surrogate for smallpox antiviral testing. The prairie dog MPXV model has been characterized and used to study the efficacy of antipoxvirus therapeutics, including recently approved TPOXX (tecovirimat). Brincidofovir (BCV; CMX001) has shown antiviral activity against double-stranded DNA viruses, including poxviruses. To determine the exposure of BCV following oral administration to prairie dogs, a pharmacokinetics (PK) study was performed. Analysis of BCV plasma concentrations indicated variability, conceivably due to the outbred nature of the animals. To determine BCV efficacy in the MPXV prairie dog model, groups of animals were intranasally challenged with 9 × 10(5) plaque-forming units (PFU; 90% lethal dose [LD(90)]) of MPXV on inoculation day 0 (ID0). Animals were divided into groups based on the first day of BCV treatment relative to inoculation day (ID-1, ID0, or ID1). A trend in efficacy was noted dependent upon treatment initiation (57% on ID-1, 43% on ID0, and 29% on ID1) but was lower than demonstrated in other animal models. Analysis of the PK data indicated that BCV plasma exposure (maximum concentration [C (max)]) and the time of the last quantifiable concentration (AUC(last)) were lower than in other animal models administered the same doses, indicating that suboptimal BCV exposure may explain the lower protective effect on survival.IMPORTANCE Preparedness activities against highly transmissible viruses with high mortality rates have been highlighted during the ongoing coronavirus disease 2019 (COVID-19) pandemic. Smallpox, caused by variola virus (VARV) infection, is highly transmissible, with an estimated 30% mortality. Through an intensive vaccination campaign, smallpox was declared eradicated in 1980, and routine smallpox vaccination of individuals ceased. Today's current population has little/no immunity against VARV. If smallpox were to reemerge, the worldwide results would be devastating. Recent FDA approval of one smallpox antiviral (tecovirimat) was a successful step in biothreat preparedness; however, orthopoxviruses can become resistant to treatment, suggesting the need for multiple therapeutics. Our paper details the efficacy of the investigational smallpox drug brincidofovir in a monkeypox virus (MPXV) animal model. Since brincidofovir has not been tested in vivo against smallpox, studies with the related virus MPXV are critical in understanding whether it would be protective in the event of a smallpox outbreak. |
Exportation of Monkeypox virus from the African continent.
Mauldin MR , McCollum AM , Nakazawa YJ , Mandra A , Whitehouse ER , Davidson W , Zhao H , Gao J , Li Y , Doty J , Yinka-Ogunleye A , Akinpelu A , Aruna O , Naidoo D , Lewandowski K , Afrough B , Graham V , Aarons E , Hewson R , Vipond R , Dunning J , Chand M , Brown C , Cohen-Gihon I , Erez N , Shifman O , Israeli O , Sharon M , Schwartz E , Beth-Din A , Zvi A , Mak TM , Ng YK , Cui L , Lin RTP , Olson VA , Brooks T , Paran N , Ihekweazu C , Reynolds MG . J Infect Dis 2020 225 (8) 1367-1376 BACKGROUND: The largest West African monkeypox outbreak began September 2017, in Nigeria. Four individuals traveling from Nigeria to the UK (2), Israel, and Singapore became the first human monkeypox cases exported from Africa, and a related nosocomial transmission event in the UK became the first confirmed human-to-human monkeypox transmission event outside of Africa. METHODS: Epidemiological and molecular data for exported and Nigerian cases were analyzed jointly to better understand the exportations in the temporal and geographic context of the outbreak. RESULTS: Isolates from all travelers and a Bayelsa case shared a most recent common ancestor and traveled to Bayelsa, Delta, or Rivers states. Genetic variation for this cluster was lower than would be expected from a random sampling of genomes from this outbreak, but data did not support direct links between travelers. CONCLUSIONS: Monophyly of exportation cases and the Bayelsa sample, along with the intermediate levels of genetic variation suggest a small pool of related isolates is the likely source for the exported infections. This may be the result of the level of genetic variation present in monkeypox isolates circulating within the contiguous region of Bayelsa, Delta, and Rivers states, or another more restricted, yet unidentified source pool. |
Conserved Oligomeric Golgi (COG) Complex Proteins Facilitate Orthopoxvirus Entry, Fusion and Spread.
Realegeno S , Priyamvada L , Kumar A , Blackburn JB , Hartloge C , Puschnik AS , Sambhara S , Olson VA , Carette JE , Lupashin V , Satheshkumar PS . Viruses 2020 12 (7) Although orthopoxviruses (OPXV) are known to encode a majority of the genes required for replication in host cells, genome-wide genetic screens have revealed that several host pathways are indispensable for OPXV infection. Through a haploid genetic screen, we previously identified several host genes required for monkeypox virus (MPXV) infection, including the individual genes that form the conserved oligomeric Golgi (COG) complex. The COG complex is an eight-protein (COG1-COG8) vesicle tethering complex important for regulating membrane trafficking, glycosylation enzymes, and maintaining Golgi structure. In this study, we investigated the role of the COG complex in OPXV infection using cell lines with individual COG gene knockout (KO) mutations. COG KO cells infected with MPXV and vaccinia virus (VACV) produced small plaques and a lower virus yield compared to wild type (WT) cells. In cells where the KO phenotype was reversed using a rescue plasmid, the size of virus plaques increased demonstrating a direct link between the decrease in viral spread and the KO of COG genes. KO cells infected with VACV displayed lower levels of viral fusion and entry compared to WT suggesting that the COG complex is important for early events in OPXV infection. Additionally, fewer actin tails were observed in VACV-infected KO cells compared to WT. Since COG complex proteins are required for cellular trafficking of glycosylated membrane proteins, the disruption of this process due to lack of individual COG complex proteins may potentially impair the virus-cell interactions required for viral entry and egress. These data validate that the COG complex previously identified in our genetic screens plays a role in OPXV infection. |
Discovery of retro-1 analogs exhibiting enhanced anti-vaccinia virus activity
Priyamvada L , Alabi P , Leon A , Kumar A , Sambhara S , Olson VA , Sello JK , Satheshkumar PS . Front Microbiol 2020 11 603 Orthopoxviruses (OPXVs) are an increasing threat to human health due to the growing population of OPXV-naive individuals after the discontinuation of routine smallpox vaccination. Antiviral drugs that are effective as postexposure treatments against variola virus (the causative agent of smallpox) or other OPXVs are critical in the event of an OPXV outbreak or exposure. The only US Food and Drug Administration-approved drug to treat smallpox, Tecovirimat (ST-246), exerts its antiviral effect by inhibiting extracellular virus (EV) formation, thereby preventing cell-cell and long-distance spread. We and others have previously demonstrated that host Golgi-associated retrograde proteins play an important role in monkeypox virus (MPXV) and vaccinia virus (VACV) EV formation. Inhibition of the retrograde pathway by small molecules such as Retro-2 has been shown to decrease VACV infection in vitro and to a lesser extent in vivo. To identify more potent inhibitors of the retrograde pathway, we screened a large panel of compounds containing a benzodiazepine scaffold like that of Retro-1, against VACV infection. We found that a subset of these compounds displayed better anti-VACV activity, causing a reduction in EV particle formation and viral spread compared to Retro-1. PA104 emerged as the most potent analog, inhibiting 90% viral spread at 1.3 muM with a high selectivity index. In addition, PA104 strongly inhibited two distinct ST-246-resistant viruses, demonstrating its potential benefit for use in combination therapy with ST-246. These data and further characterizations of the specific protein targets and in vivo efficacy of PA104 may have important implications for the design of effective antivirals against OPXV. |
Antiviral ranpirnase TMR-001 inhibits rabies virus release and cell-to-cell infection in vitro
Smith TG , Jackson FR , Morgan CN , Carson WC , Martin BE , Gallardo-Romero N , Ellison JA , Greenberg L , Hodge T , Squiquera L , Sulley J , Olson VA , Hutson CL . Viruses 2020 12 (2) Currently, no rabies virus-specific antiviral drugs are available. Ranpirnase has strong antitumor and antiviral properties associated with its ribonuclease activity. TMR-001, a proprietary bulk drug substance solution of ranpirnase, was evaluated against rabies virus in three cell types: mouse neuroblastoma, BSR (baby hamster kidney cells), and bat primary fibroblast cells. When TMR-001 was added to cell monolayers 24 h preinfection, rabies virus release was inhibited for all cell types at three time points postinfection. TMR-001 treatment simultaneous with infection and 24 h postinfection effectively inhibited rabies virus release in the supernatant and cell-to-cell spread with 50% inhibitory concentrations of 0.2-2 nM and 20-600 nM, respectively. TMR-001 was administered at 0.1 mg/kg via intraperitoneal, intramuscular, or intravenous routes to Syrian hamsters beginning 24 h before a lethal rabies virus challenge and continuing once per day for up to 10 days. TMR-001 at this dose, formulation, and route of delivery did not prevent rabies virus transit from the periphery to the central nervous system in this model (n = 32). Further aspects of local controlled delivery of other active formulations or dose concentrations of TMR-001 or ribonuclease analogues should be investigated for this class of drugs as a rabies antiviral therapeutic. |
Characterization of Monkeypox virus dissemination in the black-tailed prairie dog (Cynomys ludovicianus) through in vivo bioluminescent imaging
Weiner ZP , Salzer JS , LeMasters E , Ellison JA , Kondas AV , Morgan CN , Doty JB , Martin BE , Satheshkumar PS , Olson VA , Hutson CL . PLoS One 2019 14 (9) e0222612 Monkeypox virus (MPXV) is a member of the genus Orthopoxvirus, endemic in Central and West Africa. This viral zoonosis was introduced into the United States in 2003 via African rodents imported for the pet trade and caused 37 human cases, all linked to exposure to MPXV-infected black-tailed prairie dogs (Cynomys ludovicianus). Prairie dogs have since become a useful model of MPXV disease, utilized for testing of potential medical countermeasures. In this study, we used recombinant MPXV containing the firefly luciferase gene (luc) and in vivo imaging technology to characterize MPXV pathogenesis in the black-tailed prairie dog in real time. West African (WA) MPXV could be visualized using in vivo imaging in the nose, lymph nodes, intestines, heart, lung, kidneys, and liver as early as day 6 post infection (p.i.). By day 9 p.i., lesions became visible on the skin and in some cases in the spleen. After day 9 p.i., luminescent signal representing MPXV replication either increased, indicating a progression to what would be a fatal infection, or decreased as infection was resolved. Use of recombinant luc+ MPXV allowed for a greater understanding of how MPXV disseminates throughout the body in prairie dogs during the course of infection. This technology will be used to reduce the number of animals required in future pathogenesis studies as well as aid in determining the effectiveness of potential medical countermeasures. |
Analgesia during monkeypox virus experimental challenge studies in prairie dogs (Cynomys ludovicianus)
Hutson CL , Gallardo-Romero N , Carroll DS , Salzer JS , Ayers JD , Doty JB , Hughes CM , Nakazawa Y , Hudson P , Patel N , Keckler MS , Olson VA , Nagy T . J Am Assoc Lab Anim Sci 2019 58 (4) 485-500 Because human patients with monkeypox virus (MPXV) infection report painful symptoms, it is reasonable to assume that animals infected with MPXV experience some degree of pain. Understanding whether and how analgesics affect MPXV disease progression is crucial when planning in vivo challenge experiments. In the current study, we challenged prairie dogs with a low dose (4 x10(3) pfu) of MPXV and treated with meloxicam (NSAID) or buprenorphine (opioid); control animals did not receive analgesia or received analgesia without MPXV challenge. Subsets of animals from each group were serially euthanized during the course of the study. Disease progression and viral kinetics were similar between groups, but MXPVinfected, meloxicam-treated animals showed increasing trends of morbidity and mortality compared with other groups. Differences between no-analgesia MPXV-infected control animals and MPXV-infected animals treated with buprenorphine were minimal. The findings in the current study allow more informed decisions concerning the use of analgesics during experimental MPXV challenge studies, thereby improving animal welfare. In light of these findings, we have modified our pain scale for this animal model to include the use of buprenorphine for pain relief when warranted after MPXV challenge. |
Genome of Alaskapox Virus, A Novel Orthopoxvirus Isolated from Alaska.
Gigante CM , Gao J , Tang S , McCollum AM , Wilkins K , Reynolds MG , Davidson W , McLaughlin J , Olson VA , Li Y . Viruses 2019 11 (8) Since the eradication of smallpox, there have been increases in poxvirus infections and the emergence of several novel poxviruses that can infect humans and domestic animals. In 2015, a novel poxvirus was isolated from a resident of Alaska. Diagnostic testing and limited sequence analysis suggested this isolate was a member of the Orthopoxvirus (OPXV) genus but was highly diverged from currently known species, including Akhmeta virus. Here, we present the complete 210,797 bp genome sequence of the Alaska poxvirus isolate, containing 206 predicted open reading frames. Phylogenetic analysis of the conserved central region of the genome suggested the Alaska isolate shares a common ancestor with Old World OPXVs and is diverged from New World OPXVs. We propose this isolate as a member of a new OPXV species, Alaskapox virus (AKPV). The AKPV genome contained host range and virulence genes typical of OPXVs but lacked homologs of C4L and B7R, and the hemagglutinin gene contained a unique 120 amino acid insertion. Seven predicted AKPV proteins were most similar to proteins in non-OPXV Murmansk or NY_014 poxviruses. Genomic analysis revealed evidence suggestive of recombination with Ectromelia virus in two putative regions that contain seven predicted coding sequences, including the A-type inclusion protein. |
Inactivated rabies virus-vectored immunocontraceptive vaccine in a thermo-responsive hydrogel induces high and persistent antibodies against rabies, but insufficient antibodies against gonadotropin-releasing hormone for contraception
Wu X , Yang Y , Kling C , Seigler L , Gallardo-Romero NF , Martin BE , Smith TG , Olson VA . Vaccines (Basel) 2019 7 (3) Rabies is preventable through vaccination, but the need to mount annual canine vaccination campaigns presents major challenges in rabies control and prevention. The development of a rabies vaccine that ensures lifelong immunity and animal population management in one dose could be extremely advantageous. A nonsurgical alternative to spay/neuter is a high priority for animal welfare, but irreversible infertility in one dose has not been achieved. Towards this goal, we developed a rabies virus-vectored immunocontraceptive vaccine ERA-2GnRH, which protected against rabies virus challenge and induced >80% infertility in mice after three doses in a live, liquid-vaccine formulation (Wu et al., 2014). To improve safety and use, we formulated an inactivated vaccine in a thermo-responsive chitosan hydrogel for one-dose delivery and studied the immune responses in mice. The hydrogel did not cause any injection site reactions, and the killed ERA-2GnRH vaccine induced high and persistent rabies virus neutralizing antibodies (rVNA) in mice. The rVNA in the hydrogel group reached an average of 327.40 IU/mL, more than 200 times higher than the liquid vaccine alone. The Gonadotropin-releasing hormone (GnRH) antibodies were also present and lasted longer in the hydrogel group, but did not prevent fertility in mice, reflecting a possible threshold level of GnRH antibodies for contraception. In conclusion, the hydrogel facilitated a high and long-lasting immunity, and ERA-2GnRH is a promising dual vaccine candidate. Future studies will focus on rabies protection in target species and improving the anti-GnRH response. |
Monkeypox re-emergence in Africa: a call to expand the concept and practice of One Health
Reynolds MG , Doty JB , McCollum AM , Olson VA , Nakazawa Y . Expert Rev Anti Infect Ther 2019 17 (2) 129-139 INTRODUCTION: Monkeypox is a re-emerging viral zoonosis that occurs naturally in heavily-forested regions of West and Central Africa. Inter-human transmission of monkeypox virus, although limited, drives outbreaks, particularly in household and healthcare settings. But the available evidence suggests that without repeated zoonotic introductions, human infections would eventually cease to occur. Therefore, interrupting virus transmission from animals to humans is key to combatting this disease. Such efforts, however, are hindered by an incomplete understanding of the maintenance and transmission dynamics of the virus in its natural reservoir host(s). Areas covered: Herein we review laboratory and field studies examining the susceptibility of various animal taxa to monkeypox virus infection, and note the competence of various species to serve as reservoirs or transmission hosts. In addition, we discuss early socio-ecologic theories of monkeypox virus transmission in rural settings and review current modes of ecologic investigation-including ecologic niche modeling, and ecologic sampling-in light of their potential to identify specific animal species and features of the environment that are associated with heightened risk for human disease. Expert opinion: The role of disease ecology and scientific research in ongoing disease prevention efforts should be reinforced, particularly for wildlife-associated zoonoses such as monkeypox. Such efforts alongside those aimed at nurturing 'One Health' collaborations may ultimately hold the greatest promise for reducing human infections with this pathogen. |
An ELISA-based method for detection of rabies virus nucleoprotein-specific antibodies in human antemortem samples
Realegeno S , Niezgoda M , Yager PA , Kumar A , Hoque L , Orciari L , Sambhara S , Olson VA , Satheshkumar PS . PLoS One 2018 13 (11) e0207009 Rabies is a fatal encephalitic disease in humans and animals caused by lyssaviruses, most commonly rabies virus (RABV). Human antemortem diagnosis of rabies is a complex process involving multiple sample types and tests for the detection of antibodies, antigen (protein), and nucleic acids (genomic RNA). Serological diagnosis of human rabies includes the detection of either neutralizing or binding antibodies in the cerebrospinal fluid (CSF) or serum samples from unimmunized individuals without prior rabies vaccination or passive immunization with purified immunoglobulins. While neutralizing antibodies are targeted against the surface-expressed glycoprotein (G protein), binding antibodies to viral antigens are predominantly against the nucleoprotein (N protein), although there can be antibodies against all RABV-expressed proteins. To determine N protein-specific antibody responses in the CSF and serum during RABV infection, we developed an enzyme-linked immunosorbent assay (ELISA) with purified recombinant N protein expressed in E. coli. N protein-specific immunoglobulin (Ig) subtypes IgG and IgM were detected in the CSF or serum of previously diagnosed human rabies cases. In addition, anti-N protein seroconversion was demonstrated over the course of illness in individual rabies cases. We compared the N protein ELISA results to those of an indirect fluorescent antibody (IFA) test, the current binding antibody assay used in diagnosis, and show that our ELISA is consistent with the IFA test. Sensitivity and specificity of the N protein ELISA ranged from 78.38-100% and 75.76-96.77% with respect to the IFA results. Our data provide evidence for the use of an N protein ELISA as an additional option for the detection of RABV-specific IgG or IgM antibodies in human CSF or serum specimens. |
Multi-site evaluation of the LN34 pan-lyssavirus real-time RT-PCR assay for post-mortem rabies diagnostics.
Gigante CM , Dettinger L , Powell JW , Seiders M , Condori REC , Griesser R , Okogi K , Carlos M , Pesko K , Breckenridge M , Simon EMM , Chu Myjv , Davis AD , Brunt SJ , Orciari L , Yager P , Carson WC , Hartloge C , Saliki JT , Sanchez S , Deldari M , Hsieh K , Wadhwa A , Wilkins K , Peredo VY , Rabideau P , Gruhn N , Cadet R , Isloor S , Nath SS , Joseph T , Gao J , Wallace R , Reynolds M , Olson VA , Li Y . PLoS One 2018 13 (5) e0197074 Rabies is a fatal zoonotic disease that requires fast, accurate diagnosis to prevent disease in an exposed individual. The current gold standard for post-mortem diagnosis of human and animal rabies is the direct fluorescent antibody (DFA) test. While the DFA test has proven sensitive and reliable, it requires high quality antibody conjugates, a skilled technician, a fluorescence microscope and diagnostic specimen of sufficient quality. The LN34 pan-lyssavirus real-time RT-PCR assay represents a strong candidate for rabies post-mortem diagnostics due to its ability to detect RNA across the diverse Lyssavirus genus, its high sensitivity, its potential for use with deteriorated tissues, and its simple, easy to implement design. Here, we present data from a multi-site evaluation of the LN34 assay in 14 laboratories. A total of 2,978 samples (1,049 DFA positive) from Africa, the Americas, Asia, Europe, and the Middle East were tested. The LN34 assay exhibited low variability in repeatability and reproducibility studies and was capable of detecting viral RNA in fresh, frozen, archived, deteriorated and formalin-fixed brain tissue. The LN34 assay displayed high diagnostic specificity (99.68%) and sensitivity (99.90%) when compared to the DFA test, and no DFA positive samples were negative by the LN34 assay. The LN34 assay produced definitive findings for 80 samples that were inconclusive or untestable by DFA; 29 were positive. Five samples were inconclusive by the LN34 assay, and only one sample was inconclusive by both tests. Furthermore, use of the LN34 assay led to the identification of one false negative and 11 false positive DFA results. Together, these results demonstrate the reliability and robustness of the LN34 assay and support a role for the LN34 assay in improving rabies diagnostics and surveillance. |
Are we prepared in case of a possible smallpox-like disease emergence?
Olson VA , Shchelkunov SN . Viruses 2017 9 (9) 242 Smallpox was the first human disease to be eradicated, through a concerted vaccination campaign led by the World Health Organization. Since its eradication, routine vaccination against smallpox has ceased, leaving the world population susceptible to disease caused by orthopoxviruses. In recent decades, reports of human disease from zoonotic orthopoxviruses have increased. Furthermore, multiple reports of newly identified poxviruses capable of causing human disease have occurred. These facts raise concerns regarding both the opportunity for these zoonotic orthopoxviruses to evolve and become a more severe public health issue, as well as the risk of Variola virus (the causative agent of smallpox) to be utilized as a bioterrorist weapon. The eradication of smallpox occurred prior to the development of the majority of modern virological and molecular biological techniques. Therefore, there is a considerable amount that is not understood regarding how this solely human pathogen interacts with its host. This paper briefly recounts the history and current status of diagnostic tools, vaccines, and anti-viral therapeutics for treatment of smallpox disease. The authors discuss the importance of further research to prepare the global community should a smallpox-like virus emerge. |
The history of rabies in the Western Hemisphere
Velasco-Villa A , Mauldin MR , Shi M , Escobar LE , Gallardo-Romero NF , Damon I , Olson VA , Streicker DG , Emerson G . Antiviral Res 2017 146 221-232 Before the introduction of control programs in the 20th century, rabies in domestic dogs occurred throughout the Western Hemisphere. However, historical records and phylogenetic analysis of multiple virus isolates indicate that, before the arrival of the first European colonizers, rabies virus was likely present only in bats and skunks. Canine rabies was either rare or absent among domestic dogs of Native Americans, and first arrived when many new dog breeds were imported during the period of European colonization. The introduction of the cosmopolitan dog rabies lyssavirus variant and the marked expansion of the dog population provided ideal conditions for the flourishing of enzootic canine rabies. The shift of dog-maintained viruses into gray foxes, coyotes, skunks and other wild mesocarnivores throughout the Americas and to mongooses in the Caribbean has augmented the risk of human rabies exposures and has complicated control efforts. At the same time, the continued presence of bat rabies poses novel challenges in the absolute elimination of canine and human rabies. This article compiles existing historical and phylogenetic evidence of the origins and subsequent dynamics of rabies in the Western Hemisphere, from the era preceding the arrival of the first European colonizers through the present day. A companion article reviews the current status of canine rabies control throughout the Western Hemisphere and steps that will be required to achieve and maintain its complete elimination (Velasco-Villa et al., in press). |
Monkeypox virus host factor screen in haploid cells identifies essential role of GARP complex in extracellular virus formation.
Realegeno S , Puschnik AS , Kumar A , Goldsmith C , Burgado J , Sambhara S , Olson VA , Carroll D , Damon I , Hirata T , Kinoshita T , Carette JE , Satheshkumar PS . J Virol 2017 91 (11) Monkeypox virus (MPXV) is a human pathogen that is a member of the Orthopoxvirus genus, which includes Vaccinia virus and Variola virus (the causative agent of smallpox). Human monkeypox is considered an emerging zoonotic infectious disease. To identify host factors required for MPXV infection, we performed a genome-wide insertional mutagenesis screen in human haploid cells. The screen revealed several candidate genes, including those involved in Golgi trafficking, glycosaminoglycan biosynthesis and glycosylphosphatidylinositol (GPI) - anchor biosynthesis. We validated the role of a set of vacuolar protein sorting (VPS) genes during infection, VPS51-54, which comprise the Golgi-associated retrograde protein (GARP) complex. The GARP complex is a tethering complex involved in retrograde transport of endosomes to the trans-Golgi apparatus. Our data demonstrate that VPS52 and VPS54 were dispensable for mature virus (MV) production but were required for extracellular virus (EV) formation. For comparison, a known antiviral compound, ST-246, was used in our experiments demonstrating that EV titers in VPS52 and VPS54 knockout (KO) cells were comparable to levels exhibited by ST-246 treated wildtype cells. Confocal microscopy was used to examine actin tail formation, one of the viral egress mechanisms for cell-to-cell dissemination, and revealed an absence of actin tails in VPS52KO or VPS54KO infected cells. Further evaluation of these cells by electron microscopy demonstrated a decrease in wrapped viruses (WV) compared to wild type control. Collectively, our data demonstrate the role of GARP complex genes in double-membrane wrapping of MV necessary for EV formation, implicating the host endosomal trafficking pathway in orthopoxvirus infection.IMPORTANCE Human monkeypox is an emerging zoonotic infectious disease caused by Monkeypox virus (MPXV). Of the two MPXV clades, the Congo Basin strain is associated with severe disease, higher mortality, and increased human-to-human transmission relative to the West African strain. Monkeypox is endemic to regions of western and central Africa but was introduced into the United States in 2003 from the importation of infected animals. The threat of MPXV and other orthopoxviruses is increasing due to the absence of routine smallpox vaccination leading to a higher proportion of naive populations. In this study, we have identified and validated candidate genes that are required for MPXV infection, specifically the Golgi-associated retrograde protein (GARP) complex. Identifying host targets required for infection that prevents extracellular virus formation such as the GARP complex or the retrograde pathway can provide a potential target for anti-viral therapy. |
A rapid Orthopoxvirus purification protocol suitable for high-containment laboratories
Hughes L , Wilkins K , Goldsmith CS , Smith S , Hudson P , Patel N , Karem K , Damon I , Li Y , Olson VA , Satheshkumar PS . J Virol Methods 2017 243 68-73 Virus purification in a high-containment setting provides unique challenges due to barrier precautions and operational safety approaches that are not necessary in lower biosafety level (BSL) 2 environments. The need for high risk group pathogen diagnostic assay development, anti-viral research, pathogenesis and vaccine efficacy research necessitates work in BSL-3 and BSL-4 labs with infectious agents. When this work is performed in accordance with BSL-4 practices, modifications are often required in standard protocols. Classical virus purification techniques are difficult to execute in a BSL-3 or BSL-4 laboratory because of the work practices used in these environments. Orthopoxviruses are a family of viruses that, in some cases, requires work in a high-containment laboratory and due to size do not lend themselves to simpler purification methods. Current CDC purification techniques of orthopoxviruses uses 1,1,2-trichlorotrifluoroethane, commonly known as Genetron(R). Genetron(R) is a chlorofluorocarbon (CFC) that has been shown to be detrimental to the ozone and has been phased out and the limited amount of product makes it no longer a feasible option for poxvirus purification purposes. Here we demonstrate a new orthopoxvirus purification method that is suitable for high-containment laboratories and produces virus that is not only comparable to previous purification methods, but improves on purity and yield. |
Rapid and sensitive point-of-care detection of Orthopoxviruses by ABICAP immunofiltration
Stern D , Olson VA , Smith SK , Pietraszczyk M , Miller L , Miethe P , Dorner BG , Nitsche A . Virol J 2016 13 (1) 207 BACKGROUND: The rapid and reliable detection of infectious agents is one of the most challenging tasks in scenarios lacking well-equipped laboratory infrastructure, like diagnostics in rural areas of developing countries. Commercially available point-of-care diagnostic tests for emerging and rare diseases are particularly scarce. RESULTS: In this work we present a point-of-care test for the detection of Orthopoxviruses (OPV). The OPV ABICAP assay detects down to 1 x 104 plaque forming units/mL of OPV particles within 45 min. It can be applied to clinical material like skin crusts and detects all zoonotic OPV infecting humans, including Vaccinia, Cowpox, Monkeypox, and most importantly Variola virus. CONCLUSIONS: Given the high sensitivity and the ease of handling, the novel assay could be highly useful for on-site diagnostics of suspected Monkeypox virus infections in areas lacking proper laboratory infrastructure as well as rapid on-site testing of suspected bioterrorism samples. |
Cross-neutralizing and protective human antibody specificities to poxvirus infections
Gilchuk I , Gilchuk P , Sapparapu G , Lampley R , Singh V , Kose N , Blum DL , Hughes LJ , Satheshkumar PS , Townsend MB , Kondas AV , Reed Z , Weiner Z , Olson VA , Hammarlund E , Raue HP , Slifka MK , Slaughter JC , Graham BS , Edwards KM , Eisenberg RJ , Cohen GH , Joyce S , Crowe JE Jr . Cell 2016 167 (3) 684-694.e9 Monkeypox (MPXV) and cowpox (CPXV) are emerging agents that cause severe human infections on an intermittent basis, and variola virus (VARV) has potential for use as an agent of bioterror. Vaccinia immune globulin (VIG) has been used therapeutically to treat severe orthopoxvirus infections but is in short supply. We generated a large panel of orthopoxvirus-specific human monoclonal antibodies (Abs) from immune subjects to investigate the molecular basis of broadly neutralizing antibody responses for diverse orthopoxviruses. Detailed analysis revealed the principal neutralizing antibody specificities that are cross-reactive for VACV, CPXV, MPXV, and VARV and that are determinants of protection in murine challenge models. Optimal protection following respiratory or systemic infection required a mixture of Abs that targeted several membrane proteins, including proteins on enveloped and mature virion forms of virus. This work reveals orthopoxvirus targets for human Abs that mediate cross-protective immunity and identifies new candidate Ab therapeutic mixtures to replace VIG. |
Laboratory investigations of African pouched rats (Cricetomys gambianus) as a potential reservoir host species for Monkeypox virus
Hutson CL , Nakazawa YJ , Self J , Olson VA , Regnery RL , Braden Z , Weiss S , Malekani J , Jackson E , Tate M , Karem KL , Rocke TE , Osorio JE , Damon IK , Carroll DS . PLoS Negl Trop Dis 2015 9 (10) e0004013 Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV) and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats) and this rodent species' competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu) from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4) or West African (W-MPXV: n = 4); an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV) between 3 and 27 days post infection (p.i.) (up to 1X108 pfu/ml), with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini) can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species. |
A Multiplex PCR/LDR Assay for the Simultaneous Identification of Category A Infectious Pathogens: Agents of Viral Hemorrhagic Fever and Variola Virus.
Das S , Rundell MS , Mirza AH , Pingle MR , Shigyo K , Garrison AR , Paragas J , Smith SK , Olson VA , Larone DH , Spitzer ED , Barany F , Golightly LM . PLoS One 2015 10 (9) e0138484 CDC designated category A infectious agents pose a major risk to national security and require special action for public health preparedness. They include viruses that cause viral hemorrhagic fever (VHF) syndrome as well as variola virus, the agent of smallpox. VHF is characterized by hemorrhage and fever with multi-organ failure leading to high morbidity and mortality. Smallpox, a prior scourge, has been eradicated for decades, making it a particularly serious threat if released nefariously in the essentially non-immune world population. Early detection of the causative agents, and the ability to distinguish them from other pathogens, is essential to contain outbreaks, implement proper control measures, and prevent morbidity and mortality. We have developed a multiplex detection assay that uses several species-specific PCR primers to generate amplicons from multiple pathogens; these are then targeted in a ligase detection reaction (LDR). The resultant fluorescently-labeled ligation products are detected on a universal array enabling simultaneous identification of the pathogens. The assay was evaluated on 32 different isolates associated with VHF (ebolavirus, marburgvirus, Crimean Congo hemorrhagic fever virus, Lassa fever virus, Rift Valley fever virus, Dengue virus, and Yellow fever virus) as well as variola virus and vaccinia virus (the agent of smallpox and its vaccine strain, respectively). The assay was able to detect all viruses tested, including 8 sequences representative of different variola virus strains from the CDC repository. It does not cross react with other emerging zoonoses such as monkeypox virus or cowpox virus, or six flaviviruses tested (St. Louis encephalitis virus, Murray Valley encephalitis virus, Powassan virus, Tick-borne encephalitis virus, West Nile virus and Japanese encephalitis virus). |
Comparison of monkeypox virus clade kinetics and pathology within the prairie dog animal model using a serial sacrifice study design
Hutson CL , Carroll DS , Gallardo-Romero N , Drew C , Zaki SR , Nagy T , Hughes C , Olson VA , Sanders J , Patel N , Smith SK , Keckler MS , Karem K , Damon IK . Biomed Res Int 2015 2015 965710 Monkeypox virus (MPXV) infection of the prairie dog is valuable to studying systemic orthopoxvirus disease. To further characterize differences in MPXV clade pathogenesis, groups of prairie dogs were intranasally infected (8 x 103 p.f.u.) with Congo Basin (CB) or West African (WA) MPXV, and 28 tissues were harvested on days 2, 4, 6, 9, 12, 17, and 24 postinfection. Samples were evaluated for the presence of virus and gross and microscopic lesions. Virus was recovered from nasal mucosa, oropharyngeal lymph nodes, and spleen earlier in CB challenged animals (day 4) than WA challenged animals (day 6). For both groups, primary viremia (indicated by viral DNA) was seen on days 6-9 through day 17. CB MPXV spread more rapidly, accumulated to greater levels, and caused greater morbidity in animals compared to WA MPXV. Histopathology and immunohistochemistry (IHC) findings, however, were similar. Two animals that succumbed to disease demonstrated abundant viral antigen in all organs tested, except for brain. Dual-IHC staining of select liver and spleen sections showed that apoptotic cells (identified by TUNEL) tended to colocalize with poxvirus antigen. Interestingly splenocytes were labelled positive for apoptosis more often than hepatocytes in both MPXV groups. These findings allow for further characterization of differences between MPXV clade pathogenesis, including identifying sites that are important during early viral replication and cellular response to viral infection. |
Variola virus-specific diagnostic assays: characterization, sensitivity, and specificity.
Kondas AV , Olson VA , Li Y , Abel J , Laker M , Rose L , Wilkins K , Turner J , Kline R , Damon IK . J Clin Microbiol 2015 53 (4) 1406-10 Public health response relies upon rapid and reliable confirmation of disease by diagnostic assays. Here we detail design and validation of two variola virus-specific real-time PCR assays, since previous assays cross-reacted with newly identified cowpox viruses. Assay specificity must continually be reassessed as other closely related viruses are identified. |
In vitro efficacy of brincidofovir against variola virus
Olson VA , Smith SK , Foster S , Li Y , Lanier ER , Gates I , Trost LC , Damon IK . Antimicrob Agents Chemother 2014 58 (9) 5570-1 Brincidofovir (CMX001), a lipid conjugate of the acyclic nucleotide phosphonate cidofovir, is under development for smallpox treatment using "the Animal Rule," established by FDA in 2002. Brincidofovir reduces mortality caused by orthopoxvirus infection in animal models. Compared to cidofovir, brincidofovir has increased potency, oral administration, and no evidence of nephrotoxicity. Here we report the brincidofovir EC50 against five variola virus strains in vitro averaged 0.11 muM, nearly 100-fold more potent than cidofovir. |
Efficacy of tecovirimat (ST-246) in nonhuman primates infected with variola virus (smallpox)
Mucker EM , Goff AJ , Shamblin JD , Grosenbach DW , Damon IK , Mehal JM , Holman RC , Carroll D , Gallardo N , Olson VA , Clemmons CJ , Hudson P , Hruby DE . Antimicrob Agents Chemother 2013 57 (12) 6246-53 Naturally occurring smallpox has been eradicated but remains a considerable threat as a biowarfare/bioterrorist weapon (F. Fleck, Bull. World Health Organ. 81:917-918, 2003). While effective, the smallpox vaccine is currently not recommended for routine use in the general public due to safety concerns (http://www.bt.cdc.gov/agent/smallpox/vaccination). Safe and effective countermeasures, particularly those effective after exposure to smallpox, are needed. Currently, SIGA Technologies is developing the small-molecule oral drug, tecovirimat (previously known as ST-246), as a postexposure therapeutic treatment of orthopoxvirus disease, including smallpox. Tecovirimat has been shown to be efficacious in preventing lethal orthopoxviral disease in numerous animal models (G. Yang, D. C. Pevear, M. H. Davies, M. S. Collett, T. Bailey, et al., J. Virol. 79:13139-13149, 2005; D. C. Quenelle, R. M. Buller, S. Parker, K. A. Keith, D. E. Hruby, et al., Antimicrob. Agents Chemother., 51:689-695, 2007; E. Sbrana, R. Jordan, D. E. Hruby, R. I. Mateo, S. Y. Xiao, et al., Am. J. Trop. Med. Hyg. 76:768-773, 2007). Furthermore, in clinical trials thus far, the drug appears to be safe, with a good pharmacokinetic profile. In this study, the efficacy of tecovirimat was evaluated in both a prelesional and postlesional setting in nonhuman primates challenged intravenously with 1 x 10(8) PFU of Variola virus (VARV; the causative agent of smallpox), a model for smallpox disease in humans. Following challenge, 50% of placebo-treated controls succumbed to infection, while all tecovirimat-treated animals survived regardless of whether treatment was started at 2 or 4 days postinfection. In addition, tecovirimat treatment resulted in dramatic reductions in dermal lesion counts, oropharyngeal virus shedding, and viral DNA circulating in the blood. Although clinical disease was evident in tecovirimat-treated animals, it was generally very mild and appeared to resolve earlier than in placebo-treated controls that survived infection. Tecovirimat appears to be an effective smallpox therapeutic in nonhuman primates, suggesting that it is reasonably likely to provide therapeutic benefit in smallpox-infected humans. |
Orthopoxvirus variola infection of Cynomys ludovicianus (North American Black tailed prairie dog)
Carroll DS , Olson VA , Smith SK , Braden ZH , Patel N , Abel J , Li Y , Damon IK , Karem KL . Virology 2013 443 (2) 358-62 Since the eradication of Smallpox, researchers have attempted to study Orthopoxvirus pathogenesis and immunity in animal models in order to correlate results human smallpox. A solely human pathogen, Orthopoxvirus variola fails to produce authentic smallpox illness in any other animal species tested to date. In 2003, an outbreak in the USA of Orthopoxvirus monkeypox, revealed the susceptibility of the North American black-tailed prairie dog (Cynomys ludovicianus) to infection and fulminate disease. Prairie dogs infected with Orthopoxvirus monkeypox present with a clinical scenario similar to ordinary smallpox, including prodrome, rash, and high mortality. This study examines if Black-tailed prairie dogs can become infected with O. variola and serve as a surrogate model for the study of human smallpox disease. Substantive evidence of infection is found in immunological seroconversion of animals to either intranasal or intradermal challenges with O. variola, but in the absence of overt illness. |
Transmissibility of the monkeypox virus clades via respiratory transmission: investigation using the prairie dog-monkeypox virus challenge system
Hutson CL , Gallardo-Romero N , Carroll DS , Clemmons C , Salzer JS , Nagy T , Hughes CM , Olson VA , Karem KL , Damon IK . PLoS One 2013 8 (2) e55488 Monkeypox virus (MPXV) is endemic within Africa where it sporadically is reported to cause outbreaks of human disease. In 2003, an outbreak of human MPXV occurred in the US after the importation of infected African rodents. Since the eradication of smallpox (caused by an orthopoxvirus (OPXV) related to MPXV) and cessation of routine smallpox vaccination (with the live OPXV vaccinia), there is an increasing population of people susceptible to OPXV diseases. Previous studies have shown that the prairie dog MPXV model is a functional animal model for the study of systemic human OPXV illness. Studies with this model have demonstrated that infected animals are able to transmit the virus to naive animals through multiple routes of exposure causing subsequent infection, but were not able to prove that infected animals could transmit the virus exclusively via the respiratory route. Herein we used the model system to evaluate the hypothesis that the Congo Basin clade of MPXV is more easily transmitted, via respiratory route, than the West African clade. Using a small number of test animals, we show that transmission of viruses from each of the MPXV clade was minimal via respiratory transmission. However, transmissibility of the Congo Basin clade was slightly greater than West African MXPV clade (16.7% and 0% respectively). Based on these findings, respiratory transmission appears to be less efficient than those of previous studies assessing contact as a mechanism of transmission within the prairie dog MPXV animal model. |
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