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Abdelrahim NA, Mohamed N, Evander M, Ahlm C, Fadl-Elmula IM. Human herpes virus type-6 is associated with central nervous system infections in children in Sudan. Afr J Lab Med 2022; 11:1718. [PMID: 36263389 PMCID: PMC9575351 DOI: 10.4102/ajlm.v11i1.1718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 05/25/2022] [Indexed: 11/13/2022] Open
Abstract
Background Human herpes virus type-6 (HHV-6) is increasingly recognised as a febrile agent in children. However, less is known in sub-Saharan African countries, including Sudan. Objective We investigated the involvement of HHV-6 in paediatric central nervous system (CNS) infections in Khartoum, Sudan. Methods Febrile patients aged up to 15 years with suspected CNS infections at Omdurman Hospital for Children from 01 December 2009 to 01 August 2010 were included. Viral DNA was extracted from leftover cerebrospinal fluid (CSF) specimens and quantitatively amplified by real-time polymerase chain reaction (PCR) at Umeå University in Sweden. Results Of 503 CSF specimens, 13 (2.6%) were positive for HHV-6 (33.0% [13/40 of cases with proven infectious meningitis]). The median thermal cycle threshold for all HHV-6-positive specimens was 38 (range: 31.9–40.8). The median number of virus copies was 281.3/PCR run (1 × 105 copies/mL CSF; range: 30–44 × 103 copies/PCR run [12 × 103 – 18 × 106 copies/mL CSF]). All positive patients presented with fever and vomiting; 86.0% had seizures. The male-to-female ratio was 1:1; 50.0% were toddlers, 42.0% infants and 8.0% teenagers. Most (83.0%) were admitted in the dry season and 17.0% in the rainy season. Cerebrospinal fluid leukocytosis was seen in 33.0%, CSF glucose levels were normal in 86.0% and low in 14.0%, and CSF protein levels were low in 14.0% and high in 43.0%. Conclusion Among children in Sudan with CNS infections, HHV-6 is common. Studies on the existence and spread of HHV-6 chromosomal integration in this population are needed.
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Affiliation(s)
- Nada A Abdelrahim
- Department of Medical Microbiology, Faculty of Medical Laboratory Sciences, Nile University, Khartoum, Sudan
| | - Nahla Mohamed
- Department of Virology, Faculty of Clinical Microbiology, Umeå University, Umeå, Sweden
| | - Magnus Evander
- Department of Virology, Faculty of Clinical Microbiology, Umeå University, Umeå, Sweden
| | - Clas Ahlm
- Department of Infection and Immunology, Faculty of Clinical Microbiology, Umeå University, Umeå, Sweden
| | - Imad M Fadl-Elmula
- Department of Pathology and Clinical Genetics, Faculty of Medicine, Al-Neelain University, Khartoum, Sudan
- Assafa Academy, Kartoum, Sudan
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HHV-6-Associated Neurological Disease in Children: Epidemiologic, Clinical, Diagnostic, and Treatment Considerations. Pediatr Neurol 2020; 105:10-20. [PMID: 31932119 DOI: 10.1016/j.pediatrneurol.2019.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 10/12/2019] [Accepted: 10/17/2019] [Indexed: 02/04/2023]
Abstract
Human herpesviruses 6A and 6B, often referred to collectively as human herpesvirus 6, are a pair of beta-herpesviruses known to cause a variety of clinical syndromes in both immunocompetent and immunocompromised individuals. Most humans are infected with human herpesvirus 6B, and many with human herpesvirus 6A. Primary infection typically occurs in early childhood, although large-scale reviews on the topic are limited. Herein, the authors explore the clinical manifestations of human herpesvirus 6-associated disease in both immunocompetent and immunocompromised pediatric patients, the risk factors for development of human herpesvirus 6-associated neurological disease, the risk of autoimmunity associated with development of active or latent infection, the relevance of human herpesvirus 6-specific diagnostic tests, and the medications used to treat human herpesvirus 6. The goal of this review is to improve the current understanding of human herpesvirus 6 in pediatric populations and to examine the most effective diagnostic and therapeutic interventions in this disease state.
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Mohammadpour Touserkani F, Gaínza-Lein M, Jafarpour S, Brinegar K, Kapur K, Loddenkemper T. HHV-6 and seizure: A systematic review and meta-analysis. J Med Virol 2016; 89:161-169. [PMID: 27272972 DOI: 10.1002/jmv.24594] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2016] [Indexed: 12/26/2022]
Abstract
Human herpesvirus-6 (HHV-6) is a common infection in childhood. This systematic review aims to assess the relationship between HHV-6 infection and seizure disorders based on available literature. MEDLINE database was searched using a search strategy. We included studies that were published after 1993 in English, and described patients with HHV-6 infection and accompanying seizure or status epilepticus. We identified 503 articles, and included 147 studies. Meta-analysis results showed a 0.21 detection rate of HHV-6 in febrile seizure patients. In the febrile seizure group (110 cases), 76 patients had simple and 34 had complex febrile seizures. Patients with "HHV-6 infection and status epilepticus" had a mean age of 16.24 months. In children with febrile illnesses, a higher index of clinical suspicion for HHV-6 infection may be required. Further studies including CSF and brain tissue may be needed to validate relationships between HHV6 infection and epilepsy. J. Med. Virol. 89:161-169, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Fatemeh Mohammadpour Touserkani
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
| | - Marina Gaínza-Lein
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Universidad Austral de Chile, Valdivia, Chile
| | - Saba Jafarpour
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Katelyn Brinegar
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Division of Biomedical Engineering, Department of Medicine, Biomaterials Innovation Research Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.,Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Kush Kapur
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Tobias Loddenkemper
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
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Forest F, Duband S, Pillet S, Stachowicz ML, Cornillon J, Dumollard JM, Peoc'h M. Lethal human herpesvirus-6 encephalitis after cord blood transplant. Transpl Infect Dis 2011; 13:646-9. [PMID: 21883755 DOI: 10.1111/j.1399-3062.2011.00642.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Clinical, biological, pathological, and imaging findings were all suggestive of lethal human herpesvirus-6-associated encephalitis in a 61-year-old man who had undergone a cord blood transplant. The neuropathological findings of this unusual autopsy case and the pathogenesis of this infection in immunocompromised patients are discussed.
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Affiliation(s)
- F Forest
- Department of Pathology, University Hospital Center of Saint-Etienne, Saint-Etienne, France
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Subtype-specific, probe-based, real-time PCR for detection and typing of human herpesvirus-6 encephalitis from pediatric patients under the age of 2 years. Diagn Microbiol Infect Dis 2011; 70:223-9. [PMID: 21429693 DOI: 10.1016/j.diagmicrobio.2011.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 01/03/2011] [Accepted: 01/08/2011] [Indexed: 11/21/2022]
Abstract
To investigate the frequency of human herpesvirus-6 (HHV-6) encephalitis in pediatric patients under 2 years of age, we developed a method for the simultaneous detection and differentiation of the 2 variants of HHV-6 (HHV-6A and HHV-6B) using subtype-specific, probe-based, real-time PCR (SSPBRT-PCR) and which were further evaluated on 405 cerebrospinal fluid (CSF) specimens from children with suspected encephalitis. A total of 23 (5.70%) out of 405 CSF specimens were positive by SSPBRT-PCR, including 3 cases of HHV-6A and 20 cases of HHV-6B. The positive rate of HHV-6B was significantly higher than that of HHV-6A (P = 0.0004). Compared with the results of the conventional real-time PCR, the sensitivity and specificity of the SSPBRT-PCR assay were 95.24% and 99.22%, respectively. This study suggests a role for both variants of HHV-6 in the pathogenesis of viral encephalitis. SSPBRT-PCR can provide rapid, sensitive, and specific results for identification of HHV-6A and HHV-6B and management of HHV-6 encephalitis.
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Yoshikawa T, Ohashi M, Miyake F, Fujita A, Usui C, Sugata K, Suga S, Hashimoto S, Asano Y. Exanthem subitum-associated encephalitis: nationwide survey in Japan. Pediatr Neurol 2009; 41:353-8. [PMID: 19818937 DOI: 10.1016/j.pediatrneurol.2009.05.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2009] [Revised: 05/04/2009] [Accepted: 05/11/2009] [Indexed: 11/25/2022]
Abstract
We sought to clarify clinical features of exanthem subitum associated-encephalitis/encephalopathy, generally caused by primary human herpesvirus-6 infection in Japan. A two-part questionnaire was sent to hospitals between January 2003-December 2004. Of 3357 questionnaires, 2357 (70.2%) were returned, and 2293 (68.3%) were eligible for analysis. Eighty-six cases of exanthem subitum-associated encephalitis/encephalopathy were reported. Seventy-seven (89.5%) of 86 patients were diagnosed with human herpesvirus-6 infection by virologic examination. Although 41 (50.6%) of 81 patients had no sequelae, 38 (46.9%) had neurologic sequelae. Moreover, two fatal cases (2.5%) were reported. Pleocytosis was evident in only 4 (7.5%) of 53 patients, and cerebrospinal fluid protein levels were within normal range (23.4 +/- 14.6 mg/dL S.D.) in all patients. Human herpesvirus-6 DNA was detected in 21 (53.8%) of 39 patients. Abnormal computed tomography findings were a predictor of neurologic sequelae (P = 0.0097). As a consequence of this survey, we estimate that 61.9 cases of exanthem subitum-associated encephalitis occur every year. The disease prognosis was unexpectedly poor.
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Affiliation(s)
- Tetsushi Yoshikawa
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
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Provenzale JM, vanLandingham KE, Lewis DV, Mukundan S, White LE. Extrahippocampal involvement in human herpesvirus 6 encephalitis depicted at MR imaging. Radiology 2008; 249:955-63. [PMID: 18849501 DOI: 10.1148/radiol.2492071917] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To test the hypothesis that patterns of signal intensity abnormality in human herpesvirus 6 (HHV6)-positive patients would allow distinction from patients who did not test positive for HHV6 encephalitis. MATERIALS AND METHODS This retrospective study was performed with institutional review board committee approval by using a waiver of informed consent. Sixteen immunocompromised patients (nine males, seven females; age range, 2-39 years) underwent magnetic resonance (MR) imaging and cerebrospinal fluid polymerase chain reaction (PCR) testing for HHV6 DNA on the basis of clinical findings suspicious for encephalitis. MR images acquired during acute illness were examined without knowing PCR results. RESULTS Nine patients were HHV6 positive. Seven showed signal intensity abnormalities, with prominent involvement of the hippocampus, and six showed additional involvement of the amygdala. Three HHV6-positive patients showed signal intensity abnormality in extrahippocampal divisions of the olfactory cortex and cortical and subcortical structures that maintain prominent connections with the hippocampal formation. Among the seven HHV6-negative patients, six had abnormalities in the hippocampus but only two showed extrahippocampal involvement, which was restricted to the amygdala. CONCLUSION Most patients with HHV6 encephalitis have signal intensity abnormalities in the hippocampal formation and amygdala and, contrary to prior reports, some also have involvement of limbic structures outside of the medial temporal lobe. The presence of MR signal intensity abnormality in the medial temporal lobe should raise the diagnosis of HHV6 encephalitis in immunosuppressed patients, especially when hyperintense lesions are seen in the insular region and inferior frontal lobe.
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Affiliation(s)
- James M Provenzale
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
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Crawford JR, Kadom N, Santi MR, Mariani B, Lavenstein BL. Human herpesvirus 6 rhombencephalitis in immunocompetent children. J Child Neurol 2007; 22:1260-8. [PMID: 18006954 DOI: 10.1177/0883073807307086] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This article describes the clinical presentation, diagnostic workup, and neurologic outcome of 3 immunocompetent pediatric patients diagnosed with human herpesvirus 6 (HHV6) rhombencephalitis. Presentation of HHV6 rhombencephalitis included new onset seizures, ataxia, encephalopathy, and opsoclonus-myoclonus. Neurologic examination revealed cranial neuropathies, cerebellar dysfunction, and extremity weakness. Magnetic resonance imaging abnormalities located in the cerebellum, basal ganglia/thalamus, and cerebral hemispheres were detected in 2 patients. Diagnosis of HHV6 encephalitis was made by real-time and nested polymerase chain reaction of serum and cerebrospinal fluid. The HHV6 variant A was detected in 2 patients by sequence analysis, and HHV6 protein was detected by immunomicroscopy in a patient who underwent biopsy secondary to progressive clinical and neuroradiographic findings. Therapy with intravenous ganciclovir did not correlate with resolution of neurologic symptoms, despite eventual non-detectable HHV6. Human herpesvirus 6 should be considered in the differential diagnosis of unexplained cases of rhombencephalitis in immunocompetent children. Features may be rapidly progressive and include profound encephalopathy, seizures, ataxia, and opsoclonus-myoclonus.
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Affiliation(s)
- John R Crawford
- Department of Neurology Children's National Medical Center, George Washington University, Washington District of Columbia, USA.
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Detection and typing of human herpesvirus 6 by molecular methods in specimens from patients diagnosed with encephalitis or meningitis. J Clin Microbiol 2007; 45:3972-8. [PMID: 17942643 DOI: 10.1128/jcm.01692-07] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human herpesvirus 6 (HHV-6) was detected in specimens from patients hospitalized with symptoms of encephalitis or meningitis. A real-time PCR assay was developed which has a linear dynamic range of 5 to 5 x 10(6) copies of HHV-6 and a sensitivity of five gene copies per reaction. While the assay detects both subtypes, HHV-6A and HHV-6B, it is specific and does not cross-react with a selected specificity panel. A total of 1,482 patient specimens, which were collected between 2003 and 2007, were tested; 26 specimens from 24 patients were found to be positive for HHV-6 by real-time PCR. The HHV-6 detection rate in this population was therefore 1.75%. The majority of the specimens tested (>95%) were cerebrospinal fluid (CSF) specimens. We were able to type 20 of the 26 positive specimens by conventional PCR and sequence analysis; all were HHV-6B. Forty-two percent of the patients were 3 years of age or younger, which may indicate a primary infection in these patients. Given the ages of the remaining patients (from 4 to 81 years), their infections were most probably due to virus reactivations. Where information was available, symptoms of patients included fever (71%), altered mental status (67%), and abnormal CSF profile (75%). Fifty percent of patients of 3 years of age or younger suffered from seizures. The detection of HHV-6 in specimens from patients diagnosed with encephalitis or meningitis, in the absence of a positive PCR result for other agents, strongly suggests a role for HHV-6 in the pathogenesis of these central nervous system diseases.
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Afenjar A, Rodriguez D, Rozenberg F, Dorison N, Guët A, Mignot C, Doummar D, Billette de Villemeur T, Ponsot G. [Human herpes virus type 6, etiology of an acute encephalitis in childhood: case report]. Arch Pediatr 2007; 14:472-5. [PMID: 17306516 DOI: 10.1016/j.arcped.2006.12.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2006] [Accepted: 12/22/2006] [Indexed: 11/19/2022]
Abstract
Primary infection with human herpesvirus-6 (HHV-6) causes the classical roseola infantum. Otherwise the infection is clinically silent but it may sometimes be responsible for central nervous system involvement. In order to illustrate such a type of lesions, we report on a 16-month-old girl with acute leucoencephalitis. The disease started with pyrexia 40 degrees C, followed by an episode of seizure, erythematous rash on the trunk and then coma. Brain MRI showed wide lesions on white matter. HHV-6 DNA was detected by PCR in the CSF and serum at the acute stage, and tests for HHV-6 antibody showed a significant increase of IgG antibody titre between acute and convalescent sera. One month later complete clinical recovery was observed while the MRI showed a partial disappearance of the lesions. The sero-conversion associated with the detection of the viral DNA in the serum identified a primary HHV-6 infection and the detection of viral nucleic acid in CSF gives arguments for the responsibility of the virus in the pathogenesis. When facing an acute leuco-encephalitis in infants, it is important to perform exhaustive virology investigations to rule out the implication of HHV-6 as well as other commonly incriminated pathogens (EBV, CMV, mycoplasma, enterovirus) to avoid accusing wrongly the vaccines.
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Affiliation(s)
- A Afenjar
- Service de Neuropédiatrie, Assistance Publique-Hôpitaux de Paris, Hôpital Armand-Trousseau, 26, avenue du Docteur-A.-Netter, 75012 Paris, France.
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Millichap JG. Acute Infantile Frontal Lobe Encephalopathy. Pediatr Neurol Briefs 2006. [DOI: 10.15844/pedneurbriefs-20-3-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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