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T AM, Singh B, Rupali P. Central nervous system infections in the tropics. Curr Opin Infect Dis 2024; 37:201-210. [PMID: 38529912 DOI: 10.1097/qco.0000000000001015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
PURPOSE OF REVIEW Emerging and re-emerging central nervous system (CNS) infections are a major public health concern in the tropics. The reasons for this are myriad; climate change, rainfall, deforestation, increased vector density combined with poverty, poor sanitation and hygiene. This review focuses on pathogens, which have emerged and re-emerged, with the potential for significant morbidity and mortality. RECENT FINDINGS In recent years, multiple acute encephalitis outbreaks have been caused by Nipah virus, which carries a high case fatality. Arboviral infections, predominantly dengue, chikungunya and Zika are re-emerging increasingly especially in urban areas due to changing human habitats, vector behaviour and viral evolution. Scrub typhus, another vector borne disease caused by the bacterium Orientia tsutsugamushi , is being established as a leading cause of CNS infections in the tropics. SUMMARY A syndromic and epidemiological approach to CNS infections in the tropics is essential to plan appropriate diagnostic tests and management. Rapid diagnostic tests facilitate early diagnosis and thus help prompt initiation and focusing of therapy to prevent adverse outcomes. Vector control, cautious urbanization and deforestation, and reducing disturbance of ecosystems can help prevent spread of vector-borne diseases. Regional diagnostic and treatment approaches and specific vaccines are required to avert morbidity and mortality.
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Affiliation(s)
| | - Bhagteshwar Singh
- Tropical and Infectious Diseases Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom; Institute of Infection Veterinary & Ecological Sciences, University of Liverpool, Liverpool, United Kingdom; Department of Infectious Diseases
| | - Priscilla Rupali
- Department of Infectious Diseases, Christian Medical College, Vellore, India
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Sword J, Lee JH, Castro MA, Solomon J, Aiosa N, Reza SMS, Chu WT, Johnson JC, Bartos C, Cooper K, Jahrling PB, Johnson RF, Calcagno C, Crozier I, Kuhn JH, Hensley LE, Feuerstein IM, Mani V. Computed Tomography Imaging for Monitoring of Marburg Virus Disease: a Nonhuman Primate Proof-Of-Concept Study. Microbiol Spectr 2023; 11:e0349422. [PMID: 37036346 PMCID: PMC10269526 DOI: 10.1128/spectrum.03494-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 02/01/2023] [Indexed: 04/11/2023] Open
Abstract
Marburg virus (MARV) is a highly virulent zoonotic filovirid that causes Marburg virus disease (MVD) in humans. The pathogenesis of MVD remains poorly understood, partially due to the low number of cases that can be studied, the absence of state-of-the-art medical equipment in areas where cases are reported, and limitations on the number of animals that can be safely used in experimental studies under maximum containment animal biosafety level 4 conditions. Medical imaging modalities, such as whole-body computed tomography (CT), may help to describe disease progression in vivo, potentially replacing ethically contentious and logistically challenging serial euthanasia studies. Towards this vision, we performed a pilot study, during which we acquired whole-body CT images of 6 rhesus monkeys before and 7 to 9 days after intramuscular MARV exposure. We identified imaging abnormalities in the liver, spleen, and axillary lymph nodes that corresponded to clinical, virological, and gross pathological hallmarks of MVD in this animal model. Quantitative image analysis indicated hepatomegaly with a significant reduction in organ density (indicating fatty infiltration of the liver), splenomegaly, and edema that corresponded with gross pathological and histopathological findings. Our results indicated that CT imaging could be used to verify and quantify typical MVD pathogenesis versus altered, diminished, or absent disease severity or progression in the presence of candidate medical countermeasures, thus possibly reducing the number of animals needed and eliminating serial euthanasia. IMPORTANCE Marburg virus (MARV) is a highly virulent zoonotic filovirid that causes Marburg virus disease (MVD) in humans. Much is unknown about disease progression and, thus, prevention and treatment options are limited. Medical imaging modalities, such as whole-body computed tomography (CT), have the potential to improve understanding of MVD pathogenesis. Our study used CT to identify abnormalities in the liver, spleen, and axillary lymph nodes that corresponded to known clinical signs of MVD in this animal model. Our results indicated that CT imaging and analyses could be used to elucidate pathogenesis and possibly assess the efficacy of candidate treatments.
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Affiliation(s)
- Jennifer Sword
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
| | - Ji Hyun Lee
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
| | - Marcelo A. Castro
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
| | - Jeffrey Solomon
- Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Nina Aiosa
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
| | - Syed M. S. Reza
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Winston T. Chu
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Joshua C. Johnson
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
| | - Christopher Bartos
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
| | - Kurt Cooper
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
| | - Peter B. Jahrling
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - Reed F. Johnson
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - Claudia Calcagno
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
| | - Ian Crozier
- Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Jens H. Kuhn
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
| | - Lisa E. Hensley
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
| | - Irwin M. Feuerstein
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
| | - Venkatesh Mani
- Integrated Research Facility at Fort Detrick, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, Fort Detrick, National Institutes of Health, Fort Detrick Frederick, Maryland, USA
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Abstract
Nipah virus is an acute febrile illness that can cause fatal encephalitis. It is an emerging zoonotic paramyxovirus endemic to south-east Asia and the western Pacific, and can be transmitted by its primary reservoir of fruit bats, through intermediate animal vectors and by human-to-human spread. Outbreaks of Nipah virus encephalitis have occurred in Malaysia, Singapore, Philippines, India and Bangladesh, with the most recent outbreak occurring in Kerala, India in late 2021. Extremely high case fatality rates have been reported from these outbreaks, and to date no vaccines or therapeutic management options are available. Combining this with its propensity to present non-specifically, Nipah virus encephalitis presents a challenging diagnosis that should not be missed in patients returning from endemic regions. Raising awareness of the epidemiology, clinical presentation and risk factors of contracting Nipah virus is vital to recognise and manage potential outbreaks of this disease in the UK.
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Affiliation(s)
- Ali M Alam
- Foundation year 2 doctor, Institute of Infection, Veterinary, and Ecological Science, University of Liverpool, UK.
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Wagner ND, Liu H, Rohrs HW, Amarasinghe GK, Gross ML, Leung DW. Nipah Virus V Protein Binding Alters MDA5 Helicase Folding Dynamics. ACS Infect Dis 2022; 8:118-128. [PMID: 35026950 PMCID: PMC8762660 DOI: 10.1021/acsinfecdis.1c00403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nipah virus (NiV) is an emerging and deadly zoonotic paramyxovirus that is responsible for periodic epidemics of acute respiratory illness and encephalitis in humans. Previous studies have shown that the NiV V protein antagonizes host antiviral immunity, but the molecular mechanism is incompletely understood. To address this gap, we biochemically characterized NiV V binding to the host pattern recognition receptor MDA5. We find that the C-terminal domain of NiV V (VCTD) is sufficient to bind the MDA5SF2 domain when recombinantly co-expressed in bacteria. Analysis by hydrogen-deuterium exchange mass spectrometry (HDX-MS) studies revealed that NiV VCTD is conformationally dynamic, and binding to MDA5 reduces the dynamics of VCTD. Our results also suggest that the β-sheet region in between the MDA5 Hel1, Hel2, and Hel2i domains exhibits rapid HDX. Upon VCTD binding, these β-sheet and adjacent residues show significant protection. Collectively, our findings suggest that NiV V binding disrupts the helicase fold and dynamics of MDA5 to antagonize host antiviral immunity.
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Affiliation(s)
- Nicole D. Wagner
- Division of Infectious Diseases, John T. Milliken Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Hejun Liu
- Division of Infectious Diseases, John T. Milliken Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Henry W. Rohrs
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Gaya K. Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Daisy W. Leung
- Division of Infectious Diseases, John T. Milliken Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
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