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Chong KC, Yeoh EK, Leung CC, Lau SYF, Lam HCY, Goggins WB, Zhao S, Ran J, Mohammad KN, Chan RWY, Lai CKC, Chan PKS, Leung CSY, Chen VXY, Wang Y, Wei Y. Independent effect of weather, air pollutants, and seasonal influenza on risk of tuberculosis hospitalization: An analysis of 22-year hospital admission data. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 837:155711. [PMID: 35523336 DOI: 10.1016/j.scitotenv.2022.155711] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 03/19/2022] [Accepted: 05/01/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND While influenza infections and environmental factors have been documented as potential drivers of tuberculosis, no investigations have simultaneously examined their impact on tuberculosis at a population level. This study thereby made use of Hong Kong's surveillance data over 22 years to elucidate the temporal association between environmental influences, influenza infections, and tuberculosis activity. METHODS Weekly total numbers of hospital admissions due to tuberculosis, meteorological data, and outdoor air pollutant concentrations in Hong Kong during 1998-2019 were obtained. All-type influenza-like illness positive (ILI+) rate and type-specific ILI+ rates were used as proxies for influenza activity. Quasi-Poisson generalized additive models together with distributed lag non-linear models were used to assess the association of interest. RESULTS A total of 164,116 hospital admissions due to tuberculosis were notified in public settings over a period of 22 years. The cumulative adjusted relative risk (ARR) of hospital admission due to tuberculosis was 1.07 (95% CI, 1.00-1.14) when the mean ambient temperature increased from 15.1 °C (the 5th percentile) to 24.5 °C (median). Short-term exposure to air pollutants was not found to be statistically significantly related to tuberculosis hospitalization. Accounting for the environmental covariates in the analysis, the cumulative ARR of tuberculosis admission was elevated to 1.05 (95% CI, 1.01-1.08) when the rate of ILI+ total increased from zero to 19.9 per 1000 consultations, the 95th percentile. CONCLUSION Our findings demonstrated that increased influenza activity and higher temperature were related to a higher risk of tuberculosis admissions. Stepping up the promotion of influenza vaccination, especially before the summer season, may lower the risk of tuberculosis infection/reactivation for vulnerable groups (e.g. elderly born before the launch of Bacillus Calmette-Guérin vaccination programme).
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Affiliation(s)
- Ka Chun Chong
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China; Clinical Trials and Biostatistics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China; Centre for Health Systems and Policy Research, The Chinese University of Hong Kong, Hong Kong, China
| | - Eng Kiong Yeoh
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China; Centre for Health Systems and Policy Research, The Chinese University of Hong Kong, Hong Kong, China
| | - Chi Chiu Leung
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Steven Yuk Fai Lau
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Holly Ching Yu Lam
- National Heart & Lung Institute, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - William Bernard Goggins
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Shi Zhao
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China; Clinical Trials and Biostatistics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Jinjun Ran
- School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Kirran N Mohammad
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Renee Wan Yi Chan
- Department of Paediatrics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Christopher Koon Chi Lai
- Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Paul Kay Sheung Chan
- Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Cecilia Shih Ya Leung
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Victor Xin Yuan Chen
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Yawen Wang
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Yuchen Wei
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China; Centre for Health Systems and Policy Research, The Chinese University of Hong Kong, Hong Kong, China.
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2
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Abstract
It is well established that by modulating various immune functions, host infection may alter the course of concomitant inflammatory diseases, of both infectious and autoimmune etiologies. Beyond the major impact of commensal microbiota on the immune status, host exposure to viral, bacterial, and/or parasitic microorganisms also dramatically influences inflammatory diseases in the host, in a beneficial or harmful manner. Moreover, by modifying pathogen control and host tolerance to tissue damage, a coinfection can profoundly affect the development of a concomitant infectious disease. Here, we review the diverse mechanisms that underlie the impact of (co)infections on inflammatory disorders. We discuss epidemiological studies in the context of the hygiene hypothesis and shed light on the sometimes dual impact of germ exposure on human susceptibility to inflammatory disease. We then summarize the immunomodulatory mechanisms at play, which can involve pleiotropic effects of immune players and discuss the possibility to harness pathogen-derived compounds to the host benefit.
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3
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van der Zalm MM, Lishman J, Verhagen LM, Redfern A, Smit L, Barday M, Ruttens D, da Costa A, van Jaarsveld S, Itana J, Schrueder N, Van Schalkwyk M, Parker N, Appel I, Fourie B, Claassen M, Workman JJ, Goussard P, Van Zyl G, Rabie H. Clinical Experience With Severe Acute Respiratory Syndrome Coronavirus 2-Related Illness in Children: Hospital Experience in Cape Town, South Africa. Clin Infect Dis 2021; 72:e938-e944. [PMID: 33170927 PMCID: PMC7717210 DOI: 10.1093/cid/ciaa1666] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Children seem relatively protected from serious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related disease, but little is known about children living in settings with high tuberculosis and human immunodeficiency virus (HIV) burden. This study reflects clinical data on South African children with SARS-CoV-2. METHODS We collected clinical data of children aged <13 years with laboratory-confirmed SARS-CoV-2 presenting to Tygerberg Hospital, Cape Town, between 17 April and 24 July 2020. RESULTS One hundred fifty-nine children (median age, 48.0 months [interquartile range {IQR}, 12.0-106.0 months]) were included. Hospitalized children (n = 62), with a median age of 13.5 months (IQR, 1.8-43.5 months) were younger than children not admitted (n = 97; median age, 81.0 months [IQR, 34.5-120.5 months]; P < .01.). Thirty-three of 159 (20.8%) children had preexisting medical conditions. Fifty-one of 62 (82.3%) hospitalized children were symptomatic; lower respiratory tract infection was diagnosed in 21 of 51 (41.2%) children, and in 11 of 16 (68.8%) children <3 months of age. Respiratory support was required in 25 of 51 (49.0%) children; 13 of these (52.0%) were <3 months of age. One child was HIV infected and 11 of 51 (21.2%) were HIV exposed but uninfected, and 7 of 51 (13.7%) children had a recent or new diagnosis of tuberculosis. CONCLUSIONS Children <1 year of age hospitalized with SARS-CoV-2 in Cape Town frequently required respiratory support. Access to oxygen may be limited in some low- and middle-income countries, which could potentially drive morbidity and mortality. HIV infection was uncommon but a relationship between HIV exposure, tuberculosis, and SARS-CoV-2 should be explored.
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Affiliation(s)
- Marieke M van der Zalm
- Desmond Tutu Tuberculosis Centre, Department of Paediatrics and Child Health,
Faculty of Medicine and Health Sciences, Stellenbosch University,
Cape Town, South Africa
- Correspondence: M. M. van der Zalm, Department of Paediatrics and Child
Health, Desmond Tutu TB Centre, Stellenbosch University, Fransie van Zyl drive, 8000, Cape
Town, South Africa ()
| | - Juanita Lishman
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
| | - Lilly M Verhagen
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
- Department of Pediatric Infectious Diseases Immunology, Wilhelmina Children’s
Hospital, University Medical Centre Utrecht, Utrecht University,
Utrecht, The Netherlands
| | - Andrew Redfern
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
| | - Liezl Smit
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
| | - Mikhail Barday
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
| | - Dries Ruttens
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
- Department of Paediatrics, KU Leuven University,
Leuven, Belgium
| | - A’ishah da Costa
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
| | - Sandra van Jaarsveld
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
| | - Justina Itana
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
| | - Neshaad Schrueder
- Division of General Internal Medicine, Department of Medicine, Tygerberg
Hospital, Stellenbosch University, Cape Town,
South Africa
| | - Marije Van Schalkwyk
- Division of Adult Infectious Diseases, Department of Medicine, Tygerberg
Hospital, Stellenbosch University, Cape Town,
South Africa
| | - Noor Parker
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
| | - Ilse Appel
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
| | - Barend Fourie
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
| | - Mathilda Claassen
- Division of Medical Virology, Stellenbosch University, National Health
Laboratory services, Cape Town, South Africa
| | - Jessica J Workman
- Desmond Tutu Tuberculosis Centre, Department of Paediatrics and Child Health,
Faculty of Medicine and Health Sciences, Stellenbosch University,
Cape Town, South Africa
| | - Pierre Goussard
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
| | - Gert Van Zyl
- Division of Medical Virology, Stellenbosch University, National Health
Laboratory services, Cape Town, South Africa
| | - Helena Rabie
- Department of Paediatrics and Child Health, Tygerberg Hospital, Faculty of
Medicine and Health Sciences, Stellenbosch University, Cape
Town, South Africa
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4
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van der Zalm MM, Walters E, Claassen M, Palmer M, Seddon JA, Demers AM, Shaw ML, McCollum ED, van Zyl GU, Hesseling AC. High burden of viral respiratory co-infections in a cohort of children with suspected pulmonary tuberculosis. BMC Infect Dis 2020; 20:924. [PMID: 33276721 PMCID: PMC7716283 DOI: 10.1186/s12879-020-05653-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 11/24/2020] [Indexed: 11/16/2022] Open
Abstract
Background The presentation of pulmonary tuberculosis (PTB) in young children is often clinically indistinguishable from other common respiratory illnesses, which are frequently infections of viral aetiology. As little is known about the role of viruses in children with PTB, we investigated the prevalence of respiratory viruses in children with suspected PTB at presentation and follow-up. Methods In an observational cohort study, children < 13 years were routinely investigated for suspected PTB in Cape Town, South Africa between December 2015 and September 2017 and followed up for 24 weeks. Nasopharyngeal aspirates (NPAs) were tested for respiratory viruses using multiplex PCR at enrolment, week 4 and 8. Results Seventy-three children were enrolled [median age 22.0 months; (interquartile range 10.0–48.0); 56.2% male and 17.8% HIV-infected. Anti-tuberculosis treatment was initiated in 54.8%; of these 50.0% had bacteriologically confirmed TB. At enrolment, ≥1 virus were detected in 95.9% (70/73) children; most commonly human rhinovirus (HRV) (74.0%). HRV was more frequently detected in TB cases (85%) compared to ill controls (60.6%) (p = 0.02). Multiple viruses were detected in 71.2% of all children; 80% of TB cases and 60.6% of ill controls (p = 0.07). At follow-up, ≥1 respiratory virus was detected in 92.2% (47/51) at week 4, and 94.2% (49/52) at week 8. Conclusions We found a high prevalence of viral respiratory co-infections in children investigated for PTB, irrespective of final PTB diagnosis, which remained high during follow up. Future work should include investigating the whole respiratory ecosystem in combination with pathogen- specific immune responses.
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Affiliation(s)
- M M van der Zalm
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.
| | - E Walters
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.,Department of Paediatrics, Great North Children's Hospital, Newcastle-Upon-Tyne Health Trust, Newcastle upon Tyne, UK
| | - M Claassen
- Division of Medical Virology, Faculty of Medicine and Health Sciences, Stellenbosch University and National Health Laboratory Service, Tygerberg Hospital, Cape Town, South Africa
| | - M Palmer
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - J A Seddon
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.,Department of Infectious Diseases, Imperial College London, London, UK
| | - A M Demers
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - M L Shaw
- Department of Medical Biosciences, University of the Western Cape, Cape Town, South Africa.,Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - E D McCollum
- Eudowood Division of Pediatric Respiratory Sciences, School of Medicine, Johns Hopkins University, Baltimore, USA.,Global Program in Respiratory Sciences, Department of Pediatrics, Johns Hopkins University, Baltimore, MD, USA.,Health Systems Program, Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - G U van Zyl
- Division of Medical Virology, Faculty of Medicine and Health Sciences, Stellenbosch University and National Health Laboratory Service, Tygerberg Hospital, Cape Town, South Africa
| | - A C Hesseling
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
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5
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Honce R, Wohlgemuth N, Meliopoulos VA, Short KR, Schultz-Cherry S. Influenza in High-Risk Hosts-Lessons Learned from Animal Models. Cold Spring Harb Perspect Med 2020; 10:cshperspect.a038604. [PMID: 31871227 DOI: 10.1101/cshperspect.a038604] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Factoring significantly into the global burden of influenza disease are high-risk populations that suffer the bulk of infections. Classically, the very young, very old, and pregnant women have been identified as high-risk populations; however, recent research has uncovered several other conditions that contribute to severe infection. By using varied animal models, researchers have identified molecular mechanisms underpinning the increased likelihood for infection due to obesity and malnourishment, as well as insight into the role sex hormones play in antiviral immunity in males, in females, and across the life span. Additionally, novel comorbidity models have helped elucidate the role of chronic infectious and genetic diseases in influenza virus pathogenesis. Animal models play a vital role in understanding the contribution of host factors to influenza severity and immunity. An in-depth understanding of these host factors represents an important step in reducing the burden of influenza among the growing number of people living with one or more chronic medical conditions.
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Affiliation(s)
- Rebekah Honce
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-3678, USA.,Integrated Program in Biomedical Sciences, Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
| | - Nicholas Wohlgemuth
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-3678, USA
| | - Victoria A Meliopoulos
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-3678, USA
| | - Kirsty R Short
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Stacey Schultz-Cherry
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-3678, USA
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6
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Affiliation(s)
- Ajay Gupta
- Department of Orthopaedics, Maulana Azad Medical College and Associated LN Hospital, New Delhi, 110002 India
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7
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Walaza S, Cohen C, Tempia S, Moyes J, Nguweneza A, Madhi SA, McMorrow M, Cohen AL. Influenza and tuberculosis co-infection: A systematic review. Influenza Other Respir Viruses 2019; 14:77-91. [PMID: 31568678 PMCID: PMC6928059 DOI: 10.1111/irv.12670] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 06/26/2019] [Accepted: 06/28/2019] [Indexed: 12/14/2022] Open
Abstract
Introduction There are limited data on risk of severe disease or outcomes in patients with influenza and pulmonary tuberculosis (PTB) co‐infection compared to those with single infection. Methods We conducted a systematic review of published literature on the interaction of influenza viruses and PTB. Studies were eligible for inclusion if they presented data on prevalence, disease association, presentation or severity of laboratory‐confirmed influenza among clinically diagnosed or laboratory‐confirmed PTB cases. We searched eight databases from inception until December 2018. Summary characteristics of each study were extracted, and a narrative summary was presented. Cohort or case‐control studies were assessed for potential bias using the Newcastle‐Ottawa scale. Results We assessed 5154 abstracts, reviewed 146 manuscripts and included 19 studies fulfilling selection criteria (13 human and six animal). Of seven studies reporting on the possible effect of the underlying PTB disease in patients with influenza, three of four analytical studies reported no association with disease severity of influenza infection in those with PTB, whilst one study reported PTB as a risk factor for influenza‐associated hospitalization. An association between influenza infection and PTB disease was found in three of five analytical studies; whereas the two other studies reported a high frequency of PTB disease progression and complications among patients with seasonal influenza co‐infection. Conclusion Human analytical studies of an association between co‐infection and severe influenza‐ or PTB‐associated disease or increased prevalence of influenza co‐infection in individuals' hospitalized for PTB were not conclusive. Data are limited from large, high‐quality, analytical epidemiological studies with laboratory‐confirmed endpoints.
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Affiliation(s)
- Sibongile Walaza
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Cheryl Cohen
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Stefano Tempia
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, USA.,Influenza Program, Centers for Disease Control and Prevention, Pretoria, South Africa
| | - Jocelyn Moyes
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Athermon Nguweneza
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
| | - Shabir A Madhi
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,Medical Research Council, Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa.,Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa
| | - Meredith McMorrow
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, USA.,Influenza Program, Centers for Disease Control and Prevention, Pretoria, South Africa.,U.S. Public Health Service, Rockville, MD, USA
| | - Adam L Cohen
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, USA.,Influenza Program, Centers for Disease Control and Prevention, Pretoria, South Africa.,Global Immunization Monitoring and Surveillance, Expanded Programme on Immunization Department of Immunization, Vaccines and Biologicals World Health Organization, Geneva, Switzerland
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8
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Whittaker E, López-Varela E, Broderick C, Seddon JA. Examining the Complex Relationship Between Tuberculosis and Other Infectious Diseases in Children. Front Pediatr 2019; 7:233. [PMID: 31294001 PMCID: PMC6603259 DOI: 10.3389/fped.2019.00233] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 05/22/2019] [Indexed: 12/21/2022] Open
Abstract
Millions of children are exposed to tuberculosis (TB) each year, many of which become infected with Mycobacterium tuberculosis. Most children can immunologically contain or eradicate the organism without pathology developing. However, in a minority, the organism overcomes the immunological constraints, proliferates and causes TB disease. Each year a million children develop TB disease, with a quarter dying. While it is known that young children and those with immunodeficiencies are at increased risk of progression from TB infection to TB disease, our understanding of risk factors for this transition is limited. The most immunologically disruptive process that can happen during childhood is infection with another pathogen and yet the impact of co-infections on TB risk is poorly investigated. Many diseases have overlapping geographical distributions to TB and affect similar patient populations. It is therefore likely that infection with viruses, bacteria, fungi and protozoa may impact on the risk of developing TB disease following exposure and infection, although disentangling correlation and causation is challenging. As vaccinations also disrupt immunological pathways, these may also impact on TB risk. In this article we describe the pediatric immune response to M. tuberculosis and then review the existing evidence of the impact of co-infection with other pathogens, as well as vaccination, on the host response to M. tuberculosis. We focus on the impact of other organisms on the risk of TB disease in children, in particularly evaluating if co-infections drive host immune responses in an age-dependent way. We finally propose priorities for future research in this field. An improved understanding of the impact of co-infections on TB could assist in TB control strategies, vaccine development (for TB vaccines or vaccines for other organisms), TB treatment approaches and TB diagnostics.
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Affiliation(s)
- Elizabeth Whittaker
- Department of Paediatrics, Imperial College London, London, United Kingdom
- Department of Paediatric Infectious Diseases, Imperial College Healthcare NHS Trust, St. Mary's Campus, London, United Kingdom
| | - Elisa López-Varela
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Claire Broderick
- Department of Paediatrics, Imperial College London, London, United Kingdom
| | - James A. Seddon
- Department of Paediatrics, Imperial College London, London, United Kingdom
- Department of Paediatric Infectious Diseases, Imperial College Healthcare NHS Trust, St. Mary's Campus, London, United Kingdom
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
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9
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Ring S, Eggers L, Behrends J, Wutkowski A, Schwudke D, Kröger A, Hierweger AM, Hölscher C, Gabriel G, Schneider BE. Blocking IL-10 receptor signaling ameliorates Mycobacterium tuberculosis infection during influenza-induced exacerbation. JCI Insight 2019; 5:126533. [PMID: 30998505 PMCID: PMC6542649 DOI: 10.1172/jci.insight.126533] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Epidemiological findings indicate that coinfection with influenza viruses is associated with an increased risk of death in patients suffering from tuberculosis, but the underlying pathomechanisms are not well understood. In this study, we demonstrate that influenza A virus (IAV) coinfection rapidly impairs control of Mycobacterium tuberculosis (Mtb) in C57BL/6 mice. IAV coinfection was associated with significantly increased bacterial loads, reduced survival, and a substantial modulation of innate and adaptive immune defenses including an impaired onset and development of Mtb-specific CD4+ T cell responses and the accumulation of macrophages with increased arginase-1 production in the lungs. Our findings strongly indicate that IAV coinfection compromises the host’s ability to control Mtb infection via the production of IL-10, which was rapidly induced upon viral infection. The blockade of IL-10 receptor signaling reduced the bacterial load in coinfected mice to a level comparable to that in Mtb-only-infected animals. Taken together, our data suggest that IL-10 signaling constitutes a major pathway that enhances susceptibility to Mtb during concurrent IAV infection. IL-10R signaling constitutes a major pathway that impairs control of Mycobacterium tuberculosis during influenza co-infection.
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Affiliation(s)
- Sarah Ring
- Junior Research Group Coinfection, Priority Research Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Lars Eggers
- Junior Research Group Coinfection, Priority Research Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Jochen Behrends
- Core Facility Fluorescence Cytometry, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Adam Wutkowski
- Bioanalytical Chemistry, Priority Research Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Dominik Schwudke
- Bioanalytical Chemistry, Priority Research Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Andrea Kröger
- Institute of Medical Microbiology and Hospital Hygiene, Otto-von-Guericke-University Magdeburg, and Innate Immunity and Infection, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Alexandra Maximiliane Hierweger
- Department of Obstetrics and Fetal Medicine, Laboratory for Experimental Feto-Maternal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute for Immunology, Center for Diagnostics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Hölscher
- Infection Immunology, Priority Research Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Gülsah Gabriel
- Research Department Viral Zoonoses - One Health, Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany.,Institute of Virology, University of Veterinary Medicine, Hannover, Germany
| | - Bianca E Schneider
- Junior Research Group Coinfection, Priority Research Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
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10
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Jaganath D, Wobudeya E, Sekadde MP, Nsangi B, Haq H, Cattamanchi A. Seasonality of childhood tuberculosis cases in Kampala, Uganda, 2010-2015. PLoS One 2019; 14:e0214555. [PMID: 30964908 PMCID: PMC6456174 DOI: 10.1371/journal.pone.0214555] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 03/14/2019] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Seasonality in tuberculosis (TB) has been described, especially in children. However, few studies have assessed seasonality of TB in the equatorial region, and none in children. OBJECTIVES To assess for seasonality of childhood TB cases in Kampala, Uganda, and determine the role of temperature, rainfall patterns, and influenza cases on TB diagnoses. METHODS We retrospectively analyzed demographic and clinical data of children (under 15 years) diagnosed with TB at a pediatric TB clinic in Kampala, Uganda from 2010 to 2015. We performed decomposition analysis of the monthly case time series to assess seasonality. We compared monthly mean plots and performed Poisson regression to assess any association between TB diagnoses and temperature, rainfall, and influenza. RESULTS Of the 713 childhood TB cases diagnosed at the clinic, 609 (85%) were clinically diagnosed and 492 (69%) were pulmonary cases. There were minimal monthly variations in TB cases, with a trough in December and peaks in July and October, but there was no significant seasonality. Temperature variations did not show a clear pattern with TB diagnoses. Rainfall alternated with TB diagnoses in the first half of the year, but then overlapped in the second half and was significantly associated with TB diagnoses. Influenza cases were significantly related to TB diagnoses with (β = 0.05, 95% CI 0.01 to 0.09, p = 0.01) or without (β = 0.06, 95% CI 0.01 to 0.1, p = 0.01) rainfall, and had particular overlap with pulmonary TB cases. CONCLUSIONS Seasonal variations in childhood TB diagnoses were non-significant. Temperature did not have a clear pattern with TB diagnoses, but rainfall and influenza cases correlated with the primarily clinically diagnosed childhood TB cases.
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Affiliation(s)
- Devan Jaganath
- Division of Pediatric Infectious Diseases, University of California, San Francisco, San Francisco, United States of America
| | - Eric Wobudeya
- Directorate of Pediatrics and Child Health, Mulago National Referral Hospital, Kampala, Uganda
| | | | - Betty Nsangi
- USAID RHITES-EC, University Research Co. LLC, Kampala, Uganda
| | - Heather Haq
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Adithya Cattamanchi
- Division of Pulmonology and Critical Care Medicine, University of California, San Francisco, San Francisco, United States of America
- Center for Vulnerable Populations, Department of Medicine, University of California, San Francisco, San Francisco, United States of America
- Curry International Tuberculosis Center, University of California, San Francisco, San Francisco, United States of America
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11
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Walaza S, Tempia S, Dawood H, Variava E, Wolter N, Dreyer A, Moyes J, Von Mollendorf C, McMorrow M, Von Gottberg A, Haffejee S, Venter M, Treurnicht FK, Hellferscee O, Martinson NA, Ismail N, Cohen C. The Impact of Influenza and Tuberculosis Interaction on Mortality Among Individuals Aged ≥15 Years Hospitalized With Severe Respiratory Illness in South Africa, 2010-2016. Open Forum Infect Dis 2019; 6:ofz020. [PMID: 30906797 PMCID: PMC6424478 DOI: 10.1093/ofid/ofz020] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 01/22/2019] [Indexed: 11/12/2022] Open
Abstract
Background Data on the prevalence and impact of influenza–tuberculosis coinfection on clinical outcomes from high–HIV and –tuberculosis burden settings are limited. We explored the impact of influenza and tuberculosis coinfection on mortality among hospitalized adults with lower respiratory tract infection (LRTI). Methods We enrolled patients aged ≥15 years admitted with physician-diagnosed LRTI or suspected tuberculosis at 2 hospitals in South Africa from 2010 to 2016. Combined nasopharyngeal and oropharyngeal swabs were tested for influenza and 8 other respiratory viruses. Tuberculosis testing of sputum included smear microscopy, culture, and/or Xpert MTB/Rif. Results Among 6228 enrolled individuals, 4253 (68%) were tested for both influenza and tuberculosis. Of these, the detection rate was 6% (239/4253) for influenza, 26% (1092/4253) for tuberculosis, and 77% (3113/4053) for HIV. One percent (42/4253) tested positive for both influenza and tuberculosis. On multivariable analysis, among tuberculosis-positive patients, factors independently associated with death were age group ≥65 years compared with 15–24 years (adjusted odds ratio [aOR], 3.6; 95% confidence interval [CI], 1.2–11.0) and influenza coinfection (aOR, 2.3; 95% CI, 1.02–5.2). Among influenza-positive patients, laboratory-confirmed tuberculosis was associated with an increased risk of death (aOR, 4.5; 95% CI, 1.5–13.3). Coinfection with other respiratory viruses was not associated with increased mortality in patients positive for tuberculosis (OR, 0.7; 95% CI, 0.4–1.1) or influenza (OR, 1.6; 95% CI, 0.4–5.6). Conclusions Tuberculosis coinfection is associated with increased mortality in individuals with influenza, and influenza coinfection is associated with increased mortality in individuals with tuberculosis. These data may inform prioritization of influenza vaccines or antivirals for tuberculosis patients and inform tuberculosis testing guidelines for patients with influenza.
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Affiliation(s)
- Sibongile Walaza
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Stefano Tempia
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia.,Influenza Program, Centers for Disease Control and Prevention, Pretoria, South Africa
| | - Halima Dawood
- Pietermaritzburg Metropolitan Hospital Complex, KwaZulu-Natal, South Africa
| | - Ebrahim Variava
- Department of Medicine, Klerksdorp Tshepong Hospital, North West Province.,School of Clinical Medicine, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa.,Perinatal HIV Research Unit, MRC Soweto Matlosana Collaborating Centre for HIV/AIDS and TB
| | - Nicole Wolter
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Andries Dreyer
- Centre for Tuberculosis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
| | - Jocelyn Moyes
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Claire Von Mollendorf
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Meredith McMorrow
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia.,Influenza Program, Centers for Disease Control and Prevention, Pretoria, South Africa.,Division of Global Health Protection, Centers for Disease Control and Prevention, Pretoria, South Africa
| | - Anne Von Gottberg
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Sumayya Haffejee
- Pietermaritzburg Metropolitan Hospital Complex, KwaZulu-Natal, South Africa
| | - Marietje Venter
- Zoonosis Research Program, Department of Medical Virology, University of Pretoria, Pretoria, South Africa
| | - Florette K Treurnicht
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa
| | - Orienka Hellferscee
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Neil A Martinson
- Perinatal HIV Research Unit, MRC Soweto Matlosana Collaborating Centre for HIV/AIDS and TB.,DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, University of the Witwatersrand, Johannesburg, South Africa.,Johns Hopkins University Center for TB Research, Baltimore, Maryland
| | - Nazir Ismail
- Centre for Tuberculosis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,Faculty of Health Sciences, University of Pretoria, Pretoria
| | - Cheryl Cohen
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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12
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Mendy J, Jarju S, Heslop R, Bojang AL, Kampmann B, Sutherland JS. Changes in Mycobacterium tuberculosis-Specific Immunity With Influenza co-infection at Time of TB Diagnosis. Front Immunol 2019; 9:3093. [PMID: 30662443 PMCID: PMC6328457 DOI: 10.3389/fimmu.2018.03093] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 12/13/2018] [Indexed: 01/16/2023] Open
Abstract
Background: Prior Influenza A viral (IAV) infection has been shown to increase susceptibility to tuberculosis (TB) and TB has also been shown to be a primary cause of death during pandemics, including the Spanish Influenza outbreak of 1918–1919. The majority of data has been obtained from mouse models, thus the aim of this study was to determine the impact of Flu co-infection on host immunity and disease severity in TB patients at diagnosis. Methods: Sputum from 282 patients with active TB were analyzed for presence of FluA/FluB RNA at presentation using multiplex PCR. Sputum RNA was also analyzed for Mycobacterium tuberculosis (Mtb) load using 16S RNA amplification. Supernatants from digested sputum and Mtb antigen-stimulated whole blood were analyzed using multiplex cytokine arrays and PBMC were analyzed for cytokine production from CD4+ T, CD8+ T and Mucosal Associated Invariant T cells (MAITs). Results: 12 (4.3%) of TB patients were found to have FluA or FluB viral RNA present in their sputum at the time of TB diagnosis. The TB/Flu co-infected patients had a significantly higher bacterial load compared to those with TB mono-infection (p = 0.0026). They had lower levels of IL17A in ex vivo sputum (p = 0.0275) and higher MCP-1 (CCL2) levels in the blood following PPD stimulation (p = 0.0267). TB/Flu co-infected subjects had significantly higher IFN-γ+IL-17+CD4+ and IFN-γ+IL-17-CD8+ cells compared to TB mono-infected subjects. Conclusions: These data show that Flu co-infection at time of TB diagnosis is associated with a higher bacterial load and differential cellular and soluble profiles. These findings show for the first time the impact of TB/Flu co-infection in a human cohort and support the potential benefit of Flu vaccination in TB-endemic settings.
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Affiliation(s)
- Joseph Mendy
- Vaccines & Immunity Theme, MRC Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, Gambia
| | - Sheikh Jarju
- Vaccines & Immunity Theme, MRC Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, Gambia
| | - Rhiannon Heslop
- Vaccines & Immunity Theme, MRC Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, Gambia.,Faculty of Biosciences, The University of Manchester, Manchester, United Kingdom
| | - Adama L Bojang
- Vaccines & Immunity Theme, MRC Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, Gambia
| | - Beate Kampmann
- Vaccines & Immunity Theme, MRC Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, Gambia
| | - Jayne S Sutherland
- Vaccines & Immunity Theme, MRC Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, Gambia
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13
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Huggins MA, Jameson SC, Hamilton SE. Embracing microbial exposure in mouse research. J Leukoc Biol 2018; 105:73-79. [PMID: 30260516 DOI: 10.1002/jlb.4ri0718-273r] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 09/07/2018] [Accepted: 09/13/2018] [Indexed: 01/06/2023] Open
Abstract
Research using mouse models have contributed essential knowledge toward our current understanding of how the human immune system functions. One key difference between humans and typical laboratory mice, however, is exposure to pathogens in their respective environments. Several recent studies have highlighted that these microbial encounters shape the development and functional status of the immune system. For humans, such numerous and unavoidable encounters with viruses, bacteria, and parasites may be a defining factor in generating a healthy and robust immune system, poised to respond to new infections and to vaccination. Additionally, the commensal organisms that make up the host microbiome also change with environment and impact the immune response. Hence, there is a pressing need to generate more faithful mouse models that reflect the natural state of the human immune system. This review explores the use of new experimental mouse models designed to better understand how host-microbial interactions shape the immune response. By embracing these technologies to complement traditional mouse models, researchers can remove a significant barrier that has long separated murine and human immunologists.
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Affiliation(s)
- Mathew A Huggins
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Stephen C Jameson
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Sara E Hamilton
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota, Minneapolis, Minnesota, USA
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14
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Muflihah H, Flórido M, Lin L, Xia Y, Triccas J, Stambas J, Britton W. Sequential pulmonary immunization with heterologous recombinant influenza A virus tuberculosis vaccines protects against murine M. tuberculosis infection. Vaccine 2018; 36:2462-2470. [DOI: 10.1016/j.vaccine.2018.03.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 02/22/2018] [Accepted: 03/14/2018] [Indexed: 10/17/2022]
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15
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Che Mat NF, Siddiqui S, Mehta D, Seaver K, Banete A, Alothaimeen T, Gee K, Basta S. Lymphocytic choriomeningitis virus infection of dendritic cells interferes with TLR-induced IL-12/IL-23 cytokine production in an IL-10 independent manner. Cytokine 2018; 108:105-114. [PMID: 29602153 DOI: 10.1016/j.cyto.2018.03.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Revised: 02/25/2018] [Accepted: 03/15/2018] [Indexed: 11/25/2022]
Abstract
Dendritic cells produce IL-12 and IL-23 in response to viral and bacterial infection and these cytokines are responsible for successful pathogen clearance. How sequential viral and bacterial infections affect the production of IL-12 and IL-23 is currently not known. Our study demonstrates that in dendritic cells infected with Lymphocytic choriomeningitis virus (LCMV), TLR activation with bacterial PAMPs resulted in reduced IL-12 and IL-23 expression compared to non-infected cells. Furthermore, expression of other proinflammatory cytokines, TNF-α and IL-6, were not inhibited under these conditions. We discovered that TLR-induced phosphorylation of p38 was significantly inhibited in LCMV-infected cells. We detected enhanced expression of suppressor of cytokine signalling (SOCS)-3 and IL-10. Yet, neutralizing IL-10 did not restore IL-12/IL-23 expression. Taken together, these results show that virus infection interferes with the magnitude of TLR-mediated inflammatory responses by repressing specific cytokine expression.
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Affiliation(s)
- Nor Fazila Che Mat
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
| | - Sarah Siddiqui
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
| | - Divya Mehta
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
| | - Kyle Seaver
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
| | - Andra Banete
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
| | - Torki Alothaimeen
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada
| | - Katrina Gee
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada.
| | - Sameh Basta
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada.
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16
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Mhimbira F, Hiza H, Mbuba E, Hella J, Kamwela L, Sasamalo M, Ticlla M, Said K, Mhalu G, Chiryamkubi M, Schindler C, Reither K, Gagneux S, Fenner L. Prevalence and clinical significance of respiratory viruses and bacteria detected in tuberculosis patients compared to household contact controls in Tanzania: a cohort study. Clin Microbiol Infect 2018; 25:107.e1-107.e7. [PMID: 29581053 PMCID: PMC7128396 DOI: 10.1016/j.cmi.2018.03.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 03/04/2018] [Accepted: 03/13/2018] [Indexed: 01/27/2023]
Abstract
OBJECTIVES To describe the prevalence of respiratory pathogens in tuberculosis (TB) patients and in their household contact controls, and to determine the clinical significance of respiratory pathogens in TB patients. METHODS We studied 489 smear-positive adult TB patients and 305 household contact controls without TB with nasopharyngeal swab samples within an ongoing prospective cohort study in Dar es Salaam, Tanzania, between 2013 and 2015. We used multiplex real-time PCR to detect 16 respiratory viruses and seven bacterial pathogens from nasopharyngeal swabs. RESULTS The median age of the study participants was 33 years; 61% (484/794) were men, and 21% (168/794) were HIV-positive. TB patients had a higher prevalence of HIV (28.6%; 140/489) than controls (9.2%; 28/305). Overall prevalence of respiratory viral pathogens was 20.4% (160/794; 95%CI 17.7-23.3%) and of bacterial pathogens 38.2% (303/794; 95%CI 34.9-41.6%). TB patients and controls did not differ in the prevalence of respiratory viruses (Odds Ratio [OR] 1.00, 95%CI 0.71-1.44), but respiratory bacteria were less frequently detected in TB patients (OR 0.70, 95%CI 0.53-0.94). TB patients with both respiratory viruses and respiratory bacteria were likely to have more severe disease (adjusted OR [aOR] 1.6, 95%CI 1.1-2.4; p 0.011). TB patients with respiratory viruses tended to have more frequent lung cavitations (aOR 1.6, 95%CI 0.93-2.7; p 0.089). CONCLUSIONS Respiratory viruses are common for both TB patients and household controls. TB patients may present with more severe TB disease, particularly when they are co-infected with both bacteria and viruses.
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Affiliation(s)
- F Mhimbira
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Dar es Salaam, Tanzania; Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
| | - H Hiza
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Dar es Salaam, Tanzania
| | - E Mbuba
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Dar es Salaam, Tanzania
| | - J Hella
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Dar es Salaam, Tanzania; Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
| | - L Kamwela
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Dar es Salaam, Tanzania
| | - M Sasamalo
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Dar es Salaam, Tanzania
| | - M Ticlla
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - K Said
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Dar es Salaam, Tanzania; Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
| | - G Mhalu
- Department of Intervention and Clinical Trials, Ifakara Health Institute, Dar es Salaam, Tanzania; Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
| | - M Chiryamkubi
- Department of Curative Services, Ministry of Health, Community Development, Gender, Elderly and Children, Dar es Salaam, Tanzania
| | - C Schindler
- University of Basel, Basel, Switzerland; Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - K Reither
- University of Basel, Basel, Switzerland; Department of Medicine, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - S Gagneux
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
| | - L Fenner
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
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17
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Opatowski L, Baguelin M, Eggo RM. Influenza interaction with cocirculating pathogens and its impact on surveillance, pathogenesis, and epidemic profile: A key role for mathematical modelling. PLoS Pathog 2018; 14:e1006770. [PMID: 29447284 PMCID: PMC5814058 DOI: 10.1371/journal.ppat.1006770] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Evidence is mounting that influenza virus interacts with other pathogens colonising or infecting the human respiratory tract. Taking into account interactions with other pathogens may be critical to determining the real influenza burden and the full impact of public health policies targeting influenza. This is particularly true for mathematical modelling studies, which have become critical in public health decision-making. Yet models usually focus on influenza virus acquisition and infection alone, thereby making broad oversimplifications of pathogen ecology. Herein, we report evidence of influenza virus interactions with bacteria and viruses and systematically review the modelling studies that have incorporated interactions. Despite the many studies examining possible associations between influenza and Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Neisseria meningitidis, respiratory syncytial virus (RSV), human rhinoviruses, human parainfluenza viruses, etc., very few mathematical models have integrated other pathogens alongside influenza. The notable exception is the pneumococcus-influenza interaction, for which several recent modelling studies demonstrate the power of dynamic modelling as an approach to test biological hypotheses on interaction mechanisms and estimate the strength of those interactions. We explore how different interference mechanisms may lead to unexpected incidence trends and possible misinterpretation, and we illustrate the impact of interactions on public health surveillance using simple transmission models. We demonstrate that the development of multipathogen models is essential to assessing the true public health burden of influenza and that it is needed to help improve planning and evaluation of control measures. Finally, we identify the public health, surveillance, modelling, and biological challenges and propose avenues of research for the coming years.
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Affiliation(s)
- Lulla Opatowski
- Université de Versailles Saint Quentin, Institut Pasteur, Inserm, Paris, France
| | - Marc Baguelin
- London School of Hygiene & Tropical Medicine, London, United Kingdom
- Public Health England, London, United Kingdom
| | - Rosalind M. Eggo
- London School of Hygiene & Tropical Medicine, London, United Kingdom
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18
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Bellinghausen C, Rohde GGU, Savelkoul PHM, Wouters EFM, Stassen FRM. Viral-bacterial interactions in the respiratory tract. J Gen Virol 2016; 97:3089-3102. [PMID: 27902340 DOI: 10.1099/jgv.0.000627] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In the respiratory tract, viruses and bacteria can interact on multiple levels. It is well known that respiratory viruses, particularly influenza viruses, increase the susceptibility to secondary bacterial infections. Numerous mechanisms, including compromised physical and immunological barriers, and changes in the microenvironment have hereby been shown to contribute to the development of secondary bacterial infections. In contrast, our understanding of how bacteria shape a response to subsequent viral infection is still limited. There is emerging evidence that persistent infection (or colonization) of the lower respiratory tract (LRT) with potential pathogenic bacteria, as observed in diseases like chronic obstructive pulmonary disease or cystic fibrosis, modulates subsequent viral infections by increasing viral entry receptors and modulating the inflammatory response. Moreover, recent studies suggest that even healthy lungs are not, as had long been assumed, sterile. The composition of the lung microbiome may thus modulate responses to viral infections. Here we summarize the current knowledge on the co-pathogenesis between viruses and bacteria in LRT infections.
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Affiliation(s)
- Carla Bellinghausen
- Department of Respiratory Medicine, NUTRIM - School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, The Netherlands.,Department of Medical Microbiology, NUTRIM - School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Gernot G U Rohde
- Department of Respiratory Medicine, NUTRIM - School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Paul H M Savelkoul
- Department of Medical Microbiology, NUTRIM - School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, The Netherlands.,Department of Medical Microbiology & Infection Control, VU University Medical Center, Amsterdam, The Netherlands
| | - Emiel F M Wouters
- Department of Respiratory Medicine, NUTRIM - School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Frank R M Stassen
- Department of Medical Microbiology, NUTRIM - School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, The Netherlands
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19
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Influenza Pandemics and Tuberculosis Mortality in 1889 and 1918: Analysis of Historical Data from Switzerland. PLoS One 2016; 11:e0162575. [PMID: 27706149 PMCID: PMC5051959 DOI: 10.1371/journal.pone.0162575] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 08/24/2016] [Indexed: 12/13/2022] Open
Abstract
Background Tuberculosis (TB) mortality declined in the northern hemisphere over the last 200 years, but peaked during the Russian (1889) and the Spanish (1918) influenza pandemics. We studied the impact of these two pandemics on TB mortality. Methods We retrieved historic data from mortality registers for the city of Bern and countrywide for Switzerland. We used Poisson regression models to quantify the excess pulmonary TB (PTB) mortality attributable to influenza. Results Yearly PTB mortality rates increased during both influenza pandemics. Monthly influenza and PTB mortality rates peaked during winter and early spring. In Bern, for an increase of 100 influenza deaths (per 100,000 population) monthly PTB mortality rates increased by a factor of 1.5 (95%Cl 1.4–1.6, p<0.001) during the Russian, and 3.6 (95%Cl 0.7–18.0, p = 0.13) during the Spanish pandemic. Nationally, the factor was 2.0 (95%Cl 1.8–2.2, p<0.001) and 1.5 (95%Cl 1.1–1.9, p = 0.004), respectively. We did not observe any excess cancer or extrapulmonary TB mortality (as a negative control) during the influenza pandemics. Conclusions We demonstrate excess PTB mortality during historic influenza pandemics in Switzerland, which supports a role for influenza vaccination in PTB patients in high TB incidence countries.
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20
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Gupta A, Gupta A, Kumar A, Arora S. Immunotherapy for non-responders among patients of spinal tuberculosis. Indian J Tuberc 2016; 63:79-85. [PMID: 27451815 DOI: 10.1016/j.ijtb.2015.07.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Revised: 07/05/2015] [Accepted: 07/13/2015] [Indexed: 01/15/2023]
Abstract
BACKGROUND Combined chemo- and immunotherapy are the major advancement in the treatment of tuberculosis. Immunotherapy supposedly increases cure rate while reducing the duration of treatment and tissue damage. Non-responders are those patients of tuberculosis who do not respond to anti-tubercular therapy (ATT) in the desired manner despite the mycobacteria showing sensitivity to the given drugs. The role of immunotherapy in the treatment of this particular subset of patients has been investigated scarcely. METHODS The present study included a retrospective review of prospectively collected clinico-radiological data of 14 non-responder patients who were taking ATT for spinal tuberculosis for a mean duration of 10.3 months. An immunotherapeutic regime comprising of single intramuscular injection of vitamin D 600,000IU, 3 days course of oral albendazole 200mg daily, salmonella vaccine 0.5ml intramuscular and influenza vaccine 0.5ml intramuscular were added to ATT. The vaccines and the course of oral albendazole were repeated after a month. RESULTS Before immunotherapy, seven patients were partially dependent while other seven were completely dependent on others for activities of daily living. All except one patient after treatment became independent till last follow-up (p value <0.01). Post immunotherapy, ATT was continued for mean duration of 4.9 months with mean follow-up of 22.4 months. All patients showed good clinical response within 2-6 weeks after the initiation of immunotherapy. CONCLUSIONS The crux to success of the immunotherapy regime is its potential to restore the existing Th1 Th2 imbalance and to provide substitute to the anergic and dysfunctional immune cells.
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Affiliation(s)
- Ayush Gupta
- Department of Medicine, L.N. Hospital, New Delhi 110002, India
| | - Ajay Gupta
- Department of Orthopaedics, Maulana Azad Medical College and Associated L.N. Hospital, New Delhi 110002, India.
| | - Awkash Kumar
- Department of Orthopaedics, Maulana Azad Medical College and Associated L.N. Hospital, New Delhi 110002, India
| | - Sumit Arora
- Department of Orthopaedics, Maulana Azad Medical College and Associated L.N. Hospital, New Delhi 110002, India
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Mehta D, Petes C, Gee K, Basta S. The Role of Virus Infection in Deregulating the Cytokine Response to Secondary Bacterial Infection. J Interferon Cytokine Res 2015; 35:925-34. [PMID: 26308503 DOI: 10.1089/jir.2015.0072] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Proinflammatory cytokines are produced by macrophages and dendritic cells (DCs) after infection to stimulate T helper (Th) cells, linking innate and adaptive immunity. Virus infections can deregulate the proinflammatory cytokine response like tumor necrosis factor-α and interleukin (IL)-2, making the host more susceptible to secondary bacterial infections. Studies using various viruses such as lymphocytic choriomeningitis virus, influenza A virus, and human immunodeficiency virus have revealed several intriguing mechanisms that account for the increased susceptibility to several prevalent bacterial infections. In particular, type I interferons induced during a virus infection have been observed to play a role in suppressing the production of some key antibacterial proinflammatory cytokines such as IL-23 and IL-17. Other suppressive mechanisms as a result of cytokine deregulation by viral infections include reduced function of immune cells such as DC, macrophage, natural killer, CD4(+), and CD8(+) T cells leading to impaired clearance of secondary bacterial infections. In this study, we highlight some of the immune mechanisms that become deregulated by viral infections, and can thus become defective during secondary bacterial infections.
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Affiliation(s)
- Divya Mehta
- Department of Biomedical and Molecular Sciences, Queen's University , Kingston, Ontario, Canada
| | - Carlene Petes
- Department of Biomedical and Molecular Sciences, Queen's University , Kingston, Ontario, Canada
| | - Katrina Gee
- Department of Biomedical and Molecular Sciences, Queen's University , Kingston, Ontario, Canada
| | - Sameh Basta
- Department of Biomedical and Molecular Sciences, Queen's University , Kingston, Ontario, Canada
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Stifter SA, Feng CG. Interfering with immunity: detrimental role of type I IFNs during infection. THE JOURNAL OF IMMUNOLOGY 2015; 194:2455-65. [PMID: 25747907 DOI: 10.4049/jimmunol.1402794] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Type I IFNs are known to inhibit viral replication and mediate protection against viral infection. However, recent studies revealed that these cytokines play a broader and more fundamental role in host responses to infections beyond their well-established antiviral function. Type I IFN induction, often associated with microbial evasion mechanisms unique to virulent microorganisms, is now shown to increase host susceptibility to a diverse range of pathogens, including some viruses. This article presents an overview of the role of type I IFNs in infections with bacterial, fungal, parasitic, and viral pathogens and discusses the key mechanisms mediating the regulatory function of type I IFNs in pathogen clearance and tissue inflammation.
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Affiliation(s)
- Sebastian A Stifter
- Immunology and Host Defense Group, Department of Infectious Diseases and Immunology, Sydney Medical School, The University of Sydney, Sydney 2006, New South Wales, Australia; and Mycobacterial Research Program, Centenary Institute, Sydney 2050, New South Wales, Australia
| | - Carl G Feng
- Immunology and Host Defense Group, Department of Infectious Diseases and Immunology, Sydney Medical School, The University of Sydney, Sydney 2006, New South Wales, Australia; and Mycobacterial Research Program, Centenary Institute, Sydney 2050, New South Wales, Australia
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Excess Mortality Associated with Influenza among Tuberculosis Deaths in South Africa, 1999-2009. PLoS One 2015; 10:e0129173. [PMID: 26076197 PMCID: PMC4467974 DOI: 10.1371/journal.pone.0129173] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 05/05/2015] [Indexed: 11/25/2022] Open
Abstract
Background Published data on the interaction between influenza and pulmonary tuberculosis (PTB) are limited. We aimed to estimate the influenza-associated mortality among individuals with PTB in South Africa from 1999–2009. Methods We modelled the excess influenza-associated mortality by applying Poisson regression models to monthly PTB and non-tuberculosis respiratory deaths, using laboratory-confirmed influenza as a covariate. Results PTB deaths increased each winter, coinciding with influenza virus circulation. Among individuals of any age, mean annual influenza-associated PTB mortality rate was 164/100,000 person-years (n = 439). The rate of non-tuberculosis respiratory deaths was 27/100,000 (n = 1125) for HIV-infected and 5/100,000 (n = 2367) for HIV-uninfected individuals of all ages. Among individuals aged <65 years, influenza-associated PTB mortality risk was elevated compared to influenza-associated non-tuberculosis respiratory deaths in HIV-infected (relative risk (RR): 5.2; 95% CI: 4.6–5.9) and HIV-uninfected individuals (RR: 61.0; CI: 41.4–91.0). Among individuals aged ≥65 years, influenza-associated PTB mortality risk was elevated compared to influenza-associated non-tuberculosis respiratory deaths in HIV-uninfected individuals (RR: 13.0; 95% CI: 12.0–14.0). Conclusion We observed an increased risk of influenza-associated mortality in persons with PTB compared to non-tuberculosis respiratory deaths. If confirmed in other settings, our findings may support recommendations for active inclusion of patients with TB for influenza vaccination and empiric influenza anti-viral treatment of patients with TB during influenza epidemics.
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Bates M, Marais BJ, Zumla A. Tuberculosis Comorbidity with Communicable and Noncommunicable Diseases. Cold Spring Harb Perspect Med 2015; 5:cshperspect.a017889. [PMID: 25659380 DOI: 10.1101/cshperspect.a017889] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The 18th WHO Global Tuberculosis Annual Report indicates that there were an estimated 8.6 million incident cases of tuberculosis (TB) in 2012, which included 2.9 million women and 530,000 children. TB caused 1.3 million deaths including 320,000 human immunodeficiency virus (HIV)-infected people; three-quarters of deaths occurred in Africa and Southeast Asia. With one-third of the world's population latently infected with Mycobacterium tuberculosis (Mtb), active TB disease is primarily associated with a break down in immune surveillance. This explains the strong link between active TB disease and other communicable diseases (CDs) or noncommunicable diseases (NCDs) that exert a toll on the immune system. Comorbid NCD risk factors include diabetes, smoking, malnutrition, and chronic lung disease, all of which have increased relentlessly over the past decade in developing countries. The huge overlap between killer infections such as TB, HIV, malaria, and severe viral infections with NCDs, results in a "double burden of disease" in developing countries. The current focus on vertical disease programs fails to recognize comorbidities or to encourage joint management approaches. This review highlights major disease overlaps and discusses the rationale for better integration of tuberculosis care with services for NCDs and other infectious diseases to enhance the overall efficiency of the public health responses.
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Affiliation(s)
- Matthew Bates
- University of Zambia-University College London Medical School (UNZA-UCLMS) Research and Training Project, University Teaching Hospital, Lusaka RW1X, Zambia Center for Clinical Microbiology, Department of Infection, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Ben J Marais
- Marie Bashir Institute for Infectious Diseases and Biosecurity (MBI) and The Children's Hospital at Westmead, Sydney Medical School, University of Sydney, Sydney, Australia
| | - Alimuddin Zumla
- National Institute of Health Research, Biomedical Research Centre, Royal Free Campus Rowland Hill St, University College London Hospitals, London NW3 2PF, United Kingdom
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Flórido M, Pillay R, Gillis CM, Xia Y, Turner SJ, Triccas JA, Stambas J, Britton WJ. Epitope-specific CD4+, but not CD8+, T-cell responses induced by recombinant influenza A viruses protect against Mycobacterium tuberculosis infection. Eur J Immunol 2014; 45:780-93. [PMID: 25430701 DOI: 10.1002/eji.201444954] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 10/29/2014] [Accepted: 11/24/2014] [Indexed: 02/01/2023]
Abstract
Tuberculosis remains a global health problem, in part due to failure of the currently available vaccine, BCG, to protect adults against pulmonary forms of the disease. We explored the impact of pulmonary delivery of recombinant influenza A viruses (rIAVs) on the induction of Mycobacterium tuberculosis (M. tuberculosis)-specific CD4(+) and CD8(+) T-cell responses and the resultant protection against M. tuberculosis infection in C57BL/6 mice. Intranasal infection with rIAVs expressing a CD4(+) T-cell epitope from the Ag85B protein (PR8.p25) or CD8(+) T-cell epitope from the TB10.4 protein (PR8.TB10.4) generated strong T-cell responses to the M. tuberculosis-specific epitopes in the lung that persisted long after the rIAVs were cleared. Infection with PR8.p25 conferred protection against subsequent M. tuberculosis challenge in the lung, and this was associated with increased levels of poly-functional CD4(+) T cells at the time of challenge. By contrast, infection with PR8.TB10.4 did not induce protection despite the presence of IFN-γ-producing M. tuberculosis-specific CD8(+) T cells in the lung at the time of challenge and during infection. Therefore, the induction of pulmonary M. tuberculosis epitope-specific CD4(+), but not CD8(+) T cells, is essential for protection against acute M. tuberculosis infection in the lung.
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Affiliation(s)
- Manuela Flórido
- Tuberculosis Research Program, Centenary Institute, Newtown, NSW, Australia
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Abstract
Reverse genetics systems allow artificial generation of non-segmented and segmented negative-sense RNA viruses, like influenza viruses, entirely from cloned cDNA. Since the introduction of reverse genetics systems over a decade ago, the ability to generate ‘designer’ influenza viruses in the laboratory has advanced both basic and applied research, providing a powerful tool to investigate and characterise host–pathogen interactions and advance the development of novel therapeutic strategies. The list of applications for reverse genetics has expanded vastly in recent years. In this review, we discuss the development and implications of this technique, including the recent controversy surrounding the generation of a transmissible H5N1 influenza virus. We will focus on research involving the identification of viral protein function, development of live-attenuated influenza virus vaccines, host–pathogen interactions, immunity and the generation of recombinant influenza virus vaccine vectors for the prevention and treatment of infectious diseases and cancer.
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