Investment in Africa over the past year with regards to SARS-CoV-2 genotyping has led to a massiv... more Investment in Africa over the past year with regards to SARS-CoV-2 genotyping has led to a massive increase in the number of sequences, exceeding 100,000 genomes generated to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence within their own borders, coupled with a decrease in sequencing turnaround time. Findings from this genomic surveillance underscores the heterogeneous nature of the pandemic but we observe repeated dissemination of SARS-CoV-2 variants within the continent. Sustained investment for genomic surveillance in Africa is needed as the virus continues to evolve, particularly in the low vaccination landscape. These investments are very crucial for preparedness and response for future pathogen outbreaks.One-Sentence SummaryExpanding Africa SARS-CoV-2 sequencing capacity in a fast evolving pandemic.
SARS-CoV-2 across Africa The impact of the severe acute respiratory syndrome coronavirus 2 (SARS-... more SARS-CoV-2 across Africa The impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been hard to track in African countries, largely because of patchy data. Wilkinson et al . curated viral genomes collected in 2021 from several countries across the continent. Outbreaks during 2020 in each African country were initiated by imported cases, mostly from Europe. As the pandemic developed, case numbers in African countries were likely many times higher than reported, and subsequent waves of the pandemic appear to have been more severe. Consequently, high-transmission variants have emerged that have spread within the continent, and African countries must be included in global control efforts. —CA
Sudden infant death (SID) is an unresolved problem of high relevance and previous studies have in... more Sudden infant death (SID) is an unresolved problem of high relevance and previous studies have indicated a role of viral heart infections. The diagnosis remains difficult in clinical practice using routine diagnostic tests and must be substantially improved. A prospective study based on post-mortem samples from SID victims whose heart disease was not clinically recognized was conducted for 4 years in a Tunisian University Hospital. Pediatric cases of unnatural death served as controls. Both SID victims and controls were investigated for possible coxsackievirus-B (CV-B) infection in heart tissue. During the study period, 39 cases with a male predominance (77%) were reported. There was no positive family history of coronary artery disease among the victims. In 35 cases (90%), low birth weight and/or critical development period were reported. All SID victims had complained of mild fever and insomnia for a few days preceding death, which required infectious laboratory investigations mar...
A subset of coxsackieviruses B (CV-B) is able to initiate intestinal infection via the attachment... more A subset of coxsackieviruses B (CV-B) is able to initiate intestinal infection via the attachment to two cell surface proteins, decayaccelerating factor (DAF) and coxsackie adenovirus receptor (CAR). The aim of the present study was to investigate the expression pattern of these receptors in the polarized CaCo-2 cell line using flow cytometry. The expression of CAR-specific mRNA and proteins was analyzed by reverse transcriptase polymerase chain reaction and western blotting, respectively. Flow cytometry analysis was used to study the surface expression patterns of CAR and DAF. CAR and DAF were well detected at the surface of CaCo-2 cells by flow cytometry. Despite the fact that CAR was susceptible to the action of trypsin, a few amounts of the latter enzyme and a precise dilution did not impair its correct detection by flow cytometry. This technique was used to demonstrate that the density of cells did not influence the expression of CAR at the cell surface. CaCo-2 cells express hi...
Coxsackieviruses B (CV B) are known as the most common viral cause of human heart infections. Car... more Coxsackieviruses B (CV B) are known as the most common viral cause of human heart infections. Cardiac inflammations contribute to sudden unexpected death (SUD) significantly. The diagnosis remains difficult with the traditional diagnostic tests and must be substantially improved. This has prompted health professionals to seek new diagnostic procedures which may provide important clues regarding underlying etiology. The present study is based on patients with infectious heart diseases and SUD victims with no relevant pathologies. They were investigated for possible CV-B infection. Patients with coronary artery diseases and unnatural road and domestic accident victims served as controls. The samples were studied for CV-B applying PCR. Histopathology for inflammatory markers, immunohistochemistry (IHC) for immune inflammatory cells and the enteroviral VP1-capsid protein were performed. Overall, 102 patients and 87 SUD victims were studied. As controls, 100 patients and 54 SUD unnatural...
A West Nile (WN) fever epidemic occurred in the region of Monastir, Tunisia, between August and O... more A West Nile (WN) fever epidemic occurred in the region of Monastir, Tunisia, between August and October 2003. We attempt to describe the epidemiology, clinical presentation, and outcome of patients with confirmed West Nile virus (WNV) infection. Three groups of specimens were prepared. One was made up of serum only (n = 43), the other of cerebrospinal fluid (CSF) only (n = 30), and the third group was made up of both (n = 40). These specimens were obtained from 113 patients. A serological diagnosis and evidence of WNV genome by nested reverse-transcriptase polymerase chain reaction (nRT-PCR) and TaqMan reverse transcription-polymerase chain reaction (RT-PCR) were carried out. Thirty-eight cases (33.6%) were serologically positive. Results of nRT-PCR showed a total of 10 positive cases of WNV (8.8%) detected in group 1 (n = 1/43), group 2 (n = 5/30), and group 3 (n = 4/40) whereas the PCR TaqMan showed 18 positive samples (15.9%) found in group 1 (n = 3/43), group 2 (n ...
Transactions of the Royal Society of Tropical Medicine and Hygiene, 2010
This study aimed to evaluate the prevalence of anti-West Nile virus (WNV) IgG among two populatio... more This study aimed to evaluate the prevalence of anti-West Nile virus (WNV) IgG among two populations of Tunisian blood donors living in areas where human outbreaks of WNV have occurred. Cohorts A (Monastir) and B (Mahdia) included 742 and 102 blood donors respectively. Sera were tested by IgG ELISA test and results were confirmed by PRNT test. WNV neutralizing antibodies were detected in 32 (4.3%) and in 14 (13.7%) sera in cohorts A and B respectively. The prevalence of anti-WNV IgG was significantly higher in cohort B than in cohort A (P<0.001) and was significantly lower in females than in males (P<0.001).
Virus-induced myocarditis is a common disease even in infants and young adults, but the diagnosis... more Virus-induced myocarditis is a common disease even in infants and young adults, but the diagnosis can be difficult according to the Dallas-criteria, which have been criticized as being too unreliable. The diagnosis has been substantially improved due to immunohistochemistry (IHC) for the detection of the VP1-capsid-protein of enterovirus as well as reversetranscriptase-polymerase chain reaction assays (RT-PCR) for viral genome detection. We report an unusual case of myocarditis in a young adult athlete whose heart disease was not clinically recognized and, thus, caused his sudden unexpected death (SUD). Histopathological investigations of heart tissue samples revealed signs of myocarditis. IHC was used to detect the VP1-capsid-protein of enterovirus. RT-PCR assays were used to detect enterovirus RNA. Enterovirus myocarditis was determined as a cause of death.
Investment in Africa over the past year with regards to SARS-CoV-2 genotyping has led to a massiv... more Investment in Africa over the past year with regards to SARS-CoV-2 genotyping has led to a massive increase in the number of sequences, exceeding 100,000 genomes generated to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence within their own borders, coupled with a decrease in sequencing turnaround time. Findings from this genomic surveillance underscores the heterogeneous nature of the pandemic but we observe repeated dissemination of SARS-CoV-2 variants within the continent. Sustained investment for genomic surveillance in Africa is needed as the virus continues to evolve, particularly in the low vaccination landscape. These investments are very crucial for preparedness and response for future pathogen outbreaks.One-Sentence SummaryExpanding Africa SARS-CoV-2 sequencing capacity in a fast evolving pandemic.
SARS-CoV-2 across Africa The impact of the severe acute respiratory syndrome coronavirus 2 (SARS-... more SARS-CoV-2 across Africa The impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been hard to track in African countries, largely because of patchy data. Wilkinson et al . curated viral genomes collected in 2021 from several countries across the continent. Outbreaks during 2020 in each African country were initiated by imported cases, mostly from Europe. As the pandemic developed, case numbers in African countries were likely many times higher than reported, and subsequent waves of the pandemic appear to have been more severe. Consequently, high-transmission variants have emerged that have spread within the continent, and African countries must be included in global control efforts. —CA
Sudden infant death (SID) is an unresolved problem of high relevance and previous studies have in... more Sudden infant death (SID) is an unresolved problem of high relevance and previous studies have indicated a role of viral heart infections. The diagnosis remains difficult in clinical practice using routine diagnostic tests and must be substantially improved. A prospective study based on post-mortem samples from SID victims whose heart disease was not clinically recognized was conducted for 4 years in a Tunisian University Hospital. Pediatric cases of unnatural death served as controls. Both SID victims and controls were investigated for possible coxsackievirus-B (CV-B) infection in heart tissue. During the study period, 39 cases with a male predominance (77%) were reported. There was no positive family history of coronary artery disease among the victims. In 35 cases (90%), low birth weight and/or critical development period were reported. All SID victims had complained of mild fever and insomnia for a few days preceding death, which required infectious laboratory investigations mar...
A subset of coxsackieviruses B (CV-B) is able to initiate intestinal infection via the attachment... more A subset of coxsackieviruses B (CV-B) is able to initiate intestinal infection via the attachment to two cell surface proteins, decayaccelerating factor (DAF) and coxsackie adenovirus receptor (CAR). The aim of the present study was to investigate the expression pattern of these receptors in the polarized CaCo-2 cell line using flow cytometry. The expression of CAR-specific mRNA and proteins was analyzed by reverse transcriptase polymerase chain reaction and western blotting, respectively. Flow cytometry analysis was used to study the surface expression patterns of CAR and DAF. CAR and DAF were well detected at the surface of CaCo-2 cells by flow cytometry. Despite the fact that CAR was susceptible to the action of trypsin, a few amounts of the latter enzyme and a precise dilution did not impair its correct detection by flow cytometry. This technique was used to demonstrate that the density of cells did not influence the expression of CAR at the cell surface. CaCo-2 cells express hi...
Coxsackieviruses B (CV B) are known as the most common viral cause of human heart infections. Car... more Coxsackieviruses B (CV B) are known as the most common viral cause of human heart infections. Cardiac inflammations contribute to sudden unexpected death (SUD) significantly. The diagnosis remains difficult with the traditional diagnostic tests and must be substantially improved. This has prompted health professionals to seek new diagnostic procedures which may provide important clues regarding underlying etiology. The present study is based on patients with infectious heart diseases and SUD victims with no relevant pathologies. They were investigated for possible CV-B infection. Patients with coronary artery diseases and unnatural road and domestic accident victims served as controls. The samples were studied for CV-B applying PCR. Histopathology for inflammatory markers, immunohistochemistry (IHC) for immune inflammatory cells and the enteroviral VP1-capsid protein were performed. Overall, 102 patients and 87 SUD victims were studied. As controls, 100 patients and 54 SUD unnatural...
A West Nile (WN) fever epidemic occurred in the region of Monastir, Tunisia, between August and O... more A West Nile (WN) fever epidemic occurred in the region of Monastir, Tunisia, between August and October 2003. We attempt to describe the epidemiology, clinical presentation, and outcome of patients with confirmed West Nile virus (WNV) infection. Three groups of specimens were prepared. One was made up of serum only (n = 43), the other of cerebrospinal fluid (CSF) only (n = 30), and the third group was made up of both (n = 40). These specimens were obtained from 113 patients. A serological diagnosis and evidence of WNV genome by nested reverse-transcriptase polymerase chain reaction (nRT-PCR) and TaqMan reverse transcription-polymerase chain reaction (RT-PCR) were carried out. Thirty-eight cases (33.6%) were serologically positive. Results of nRT-PCR showed a total of 10 positive cases of WNV (8.8%) detected in group 1 (n = 1/43), group 2 (n = 5/30), and group 3 (n = 4/40) whereas the PCR TaqMan showed 18 positive samples (15.9%) found in group 1 (n = 3/43), group 2 (n ...
Transactions of the Royal Society of Tropical Medicine and Hygiene, 2010
This study aimed to evaluate the prevalence of anti-West Nile virus (WNV) IgG among two populatio... more This study aimed to evaluate the prevalence of anti-West Nile virus (WNV) IgG among two populations of Tunisian blood donors living in areas where human outbreaks of WNV have occurred. Cohorts A (Monastir) and B (Mahdia) included 742 and 102 blood donors respectively. Sera were tested by IgG ELISA test and results were confirmed by PRNT test. WNV neutralizing antibodies were detected in 32 (4.3%) and in 14 (13.7%) sera in cohorts A and B respectively. The prevalence of anti-WNV IgG was significantly higher in cohort B than in cohort A (P<0.001) and was significantly lower in females than in males (P<0.001).
Virus-induced myocarditis is a common disease even in infants and young adults, but the diagnosis... more Virus-induced myocarditis is a common disease even in infants and young adults, but the diagnosis can be difficult according to the Dallas-criteria, which have been criticized as being too unreliable. The diagnosis has been substantially improved due to immunohistochemistry (IHC) for the detection of the VP1-capsid-protein of enterovirus as well as reversetranscriptase-polymerase chain reaction assays (RT-PCR) for viral genome detection. We report an unusual case of myocarditis in a young adult athlete whose heart disease was not clinically recognized and, thus, caused his sudden unexpected death (SUD). Histopathological investigations of heart tissue samples revealed signs of myocarditis. IHC was used to detect the VP1-capsid-protein of enterovirus. RT-PCR assays were used to detect enterovirus RNA. Enterovirus myocarditis was determined as a cause of death.
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