1
|
Crump JA, Nyirenda TS, Kalonji LM, Phoba MF, Tack B, Platts-Mills JA, Gordon MA, Kariuki SM. Nontyphoidal Salmonella Invasive Disease: Challenges and Solutions. Open Forum Infect Dis 2023; 10:S32-S37. [PMID: 37274526 PMCID: PMC10236517 DOI: 10.1093/ofid/ofad020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023] Open
Abstract
Nontyphoidal Salmonella are a leading cause of community-onset bacteremia and other serious infections in sub-Saharan African countries where large studies indicate that they are an uncommon cause of moderate-to-severe diarrhea. Approximately 535 000 nontyphoidal Salmonella invasive disease illnesses and 77 500 deaths were estimated to occur in 2017; 422 000 (78.9%) illnesses and 66 500 (85.9%) deaths in countries in sub-Saharan Africa. Lineages of Salmonella enterica serovar Typhimurium sequence type (ST) 313 and lineages of Salmonella enterica serovar Enteritidis ST11 dominate as causes of invasive disease. A major reservoir for these specific strains outside of humans has not been identified to date. Human fecal shedding of such strains is common in areas where nontyphoidal Salmonella invasive disease incidence is high. The case-fatality ratio of nontyphoidal Salmonella invasive disease is approximately 15%. Early diagnosis and treatment are needed to avert fatal outcomes. Antimicrobial resistance, including multiple drug resistance, decreased fluoroquinolone susceptibility, and resistance to third-generation cephalosporins, is increasing in prevalence and is likely to further compromise patient outcomes. Naturally acquired immunity against invasive disease develops in children aged >3 years in endemic areas, likely mediated in part by the sequential acquisition of T-cell immunity, followed by antigen-specific immunoglobulin G antibodies. Vaccines in preclinical or clinical development include live-attenuated S. enterica serovar Typhimurium, nontyphoidal S. enterica core and O-polysaccharide glycoconjugates, multiple antigen-presenting system complexes, and generalized modules for membrane antigens vaccines. The latter are in phase I trials in Europe and Africa. Both vaccine use, and other effective, evidence-based nonvaccine interventions, are needed to prevent and control nontyphoidal Salmonella invasive disease.
Collapse
Affiliation(s)
- John A Crump
- Correspondence: John A. Crump, MB ChB, MD, DTM&H, Professor of Medicine, Pathology, and Global Health, Centre for International Health, University of Otago, PO Box 56, Dunedin 9054, New Zealand (). Samuel M. Kariuki, BVM, MSc, PhD, Professor, Director of Research and Development and Acting Director, Kenya Medical Research Institute, PO Box 54840 00200, Nairobi, Kenya ()
| | - Tonney S Nyirenda
- Department of Pathology, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Lisette Mbuyi Kalonji
- Department of Medical Biology, University Hospital of Kinshasa, Kinshasa, Democratic Republic of the Congo
- Department of Microbiology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo
| | - Marie-France Phoba
- Department of Medical Biology, University Hospital of Kinshasa, Kinshasa, Democratic Republic of the Congo
- Department of Microbiology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo
| | - Bieke Tack
- Department of Clinical Science, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
| | - James A Platts-Mills
- Division of Infectious Diseases and International Health, School of Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - Melita A Gordon
- Malawi Liverpool Wellcome Trust Programme, Blantyre, Malawi
- Institute of Infection, Veterinary, and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Samuel M Kariuki
- Correspondence: John A. Crump, MB ChB, MD, DTM&H, Professor of Medicine, Pathology, and Global Health, Centre for International Health, University of Otago, PO Box 56, Dunedin 9054, New Zealand (). Samuel M. Kariuki, BVM, MSc, PhD, Professor, Director of Research and Development and Acting Director, Kenya Medical Research Institute, PO Box 54840 00200, Nairobi, Kenya ()
| |
Collapse
|
2
|
Dale H, Chirwa E, Patel P, Makuta G, Mwakiseghile F, Misiri T, Kadwala I, Mbewe M, Banda H, Silungwe N, Chizani K, Kambiya P, Henrion M, French N, Nyirenda T, Gordon M. Understanding the epidemiology of iNTS disease in Africa in preparation for future iNTS- vaccine studies in endemic countries: Seroepidemiology in Africa of iNTS (SAiNTS) Study Protocol [Version 9.0]. Wellcome Open Res 2023. [DOI: 10.12688/wellcomeopenres.18054.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Background: Non-typhoidal Salmonella (NTS) are a major cause of bloodstream infections amongst children in sub-Saharan Africa. A clear understanding of the seroepidemiology and correlates of protection for invasive NTS (iNTS) in relation to key risk factors (malaria, anaemia, malnutrition) in children in Africa is needed to inform strategies for disease control including vaccine implementation. Methodology: The SAiNTS study is a prospective community cohort study with paired serology samples from 2500 children 0-5 years at baseline and three months to measure age-stratified acquisition of lipopolysaccharide (LPS) O-antigen antibody (IgG) and serum bactericidal activity to the main serovars causing iNTS (Salmonella typhimurium and S. enteritidis). Children are selected from mapped and censused randomly selected households in Chikwawa, Malawi; an area with substantial malaria burden. The sampling framework is set within a malaria vaccination (RTS,S/ AS01) phase 4 cluster randomized trial (EPIMAL), allowing exploration of the impact of malaria vaccination on acquisition of immunity to NTS. Data on risk factors for invasive disease: malaria, anaemia and malnutrition as well as indicators of socioeconomic status and water and sanitation, will be collected using rapid diagnostic tests, anthropometry and electronic CRF’s. Stool sample analysis includes NTS culture and pan-Salmonella polymerase chain reaction to assess enteric exposure and biomarkers of environmental enteric dysfunction. Cases with iNTS disease will be followed up for comparison with community controls. Conclusions: The final cohort of 2500 children will allow investigation into the impact of risk factors for iNTS on the acquisition of immunity in children 0-5 years in an endemic setting, including comparisons to partner sero-epidemiology studies in three other sub-Saharan African sites. The data generated will be key to informing iNTS disease control measures including targeted risk factor interventions and vaccine implementation through investigation of correlates of protection and identifying windows of immune susceptibility in at-risk populations.
Collapse
|
3
|
Richie TL, Church LWP, Murshedkar T, Billingsley PF, James ER, Chen MC, Abebe Y, KC N, Chakravarty S, Dolberg D, Healy SA, Diawara H, Sissoko MS, Sagara I, Cook DM, Epstein JE, Mordmüller B, Kapulu M, Kreidenweiss A, Franke-Fayard B, Agnandji ST, López Mikue MSA, McCall MBB, Steinhardt L, Oneko M, Olotu A, Vaughan AM, Kublin JG, Murphy SC, Jongo S, Tanner M, Sirima SB, Laurens MB, Daubenberger C, Silva JC, Lyke KE, Janse CJ, Roestenberg M, Sauerwein RW, Abdulla S, Dicko A, Kappe SHI, Lee Sim BK, Duffy PE, Kremsner PG, Hoffman SL. Sporozoite immunization: innovative translational science to support the fight against malaria. Expert Rev Vaccines 2023; 22:964-1007. [PMID: 37571809 PMCID: PMC10949369 DOI: 10.1080/14760584.2023.2245890] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 08/04/2023] [Indexed: 08/13/2023]
Abstract
INTRODUCTION Malaria, a devastating febrile illness caused by protozoan parasites, sickened 247,000,000 people in 2021 and killed 619,000, mostly children and pregnant women in sub-Saharan Africa. A highly effective vaccine is urgently needed, especially for Plasmodium falciparum (Pf), the deadliest human malaria parasite. AREAS COVERED Sporozoites (SPZ), the parasite stage transmitted by Anopheles mosquitoes to humans, are the only vaccine immunogen achieving >90% efficacy against Pf infection. This review describes >30 clinical trials of PfSPZ vaccines in the U.S.A., Europe, Africa, and Asia, based on first-hand knowledge of the trials and PubMed searches of 'sporozoites,' 'malaria,' and 'vaccines.' EXPERT OPINION First generation (radiation-attenuated) PfSPZ vaccines are safe, well tolerated, 80-100% efficacious against homologous controlled human malaria infection (CHMI) and provide 18-19 months protection without boosting in Africa. Second generation chemo-attenuated PfSPZ are more potent, 100% efficacious against stringent heterologous (variant strain) CHMI, but require a co-administered drug, raising safety concerns. Third generation, late liver stage-arresting, replication competent (LARC), genetically-attenuated PfSPZ are expected to be both safe and highly efficacious. Overall, PfSPZ vaccines meet safety, tolerability, and efficacy requirements for protecting pregnant women and travelers exposed to Pf in Africa, with licensure for these populations possible within 5 years. Protecting children and mass vaccination programs to block transmission and eliminate malaria are long-term objectives.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Sara A. Healy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Halimatou Diawara
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Mahamadou S. Sissoko
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Issaka Sagara
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - David M. Cook
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Judith E. Epstein
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Benjamin Mordmüller
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Melissa Kapulu
- Biosciences Department, Kenya Medical Research Institute KEMRI-Wellcome Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Andrea Kreidenweiss
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | | | - Selidji T. Agnandji
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | | | - Matthew B. B. McCall
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - Laura Steinhardt
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Martina Oneko
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya
| | - Ally Olotu
- Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Ashley M. Vaughan
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - James G. Kublin
- Department of Global Health, University of Washington, Seattle, WA, USA
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Sean C. Murphy
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
- Center for Emerging and Re-emerging Infectious Diseases and Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Said Jongo
- Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Marcel Tanner
- Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Matthew B. Laurens
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Claudia Daubenberger
- Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Joana C. Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kirsten E. Lyke
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Chris J. Janse
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Meta Roestenberg
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
| | - Robert W. Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Salim Abdulla
- Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Alassane Dicko
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Stefan H. I. Kappe
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | | | - Patrick E. Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Peter G. Kremsner
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | | |
Collapse
|
4
|
Coulibaly D, Kone AK, Traore K, Niangaly A, Kouriba B, Arama C, Zeguime A, Dolo A, Lyke KE, Plowe CV, Abebe Y, Potter GE, Kennedy JK, Galbiati SM, Nomicos E, Deye GA, Richie TL, James ER, KC N, Sim BKL, Hoffman SL, Doumbo OK, Thera MA, Laurens MB. PfSPZ-CVac malaria vaccine demonstrates safety among malaria-experienced adults: A randomized, controlled phase 1 trial. EClinicalMedicine 2022; 52:101579. [PMID: 35928033 PMCID: PMC9343417 DOI: 10.1016/j.eclinm.2022.101579] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Plasmodium falciparum (Pf) Sporozoite (SPZ) Chemoprophylaxis Vaccine (PfSPZ-CVac) involves concurrently administering infectious PfSPZ and malaria drug, often chloroquine (CQ), to kill liver-emerging parasites. PfSPZ-CVac (CQ) protected 100% of malaria-naïve participants against controlled human malaria infection. We investigated the hypothesis that PfSPZ-CVac (CQ) is safe and efficacious against seasonal, endemic Pf in malaria-exposed adults. METHODS Healthy 18-45 year olds were enrolled in a double-blind, placebo-controlled trial in Bougoula-Hameau, Mali, randomized 1:1 to 2.048 × 105 PfSPZ (PfSPZ Challenge) or normal saline administered by direct venous inoculation at 0, 4, 8 weeks. Syringes were prepared by pharmacy staff using online computer-based enrolment that randomized allocations. Clinical team and participant masking was assured by identical appearance of vaccine and placebo. Participants received chloroquine 600mg before first vaccination, 10 weekly 300mg doses during vaccination, then seven daily doses of artesunate 200mg before 24-week surveillance during the rainy season. Safety outcomes were solicited adverse events (AEs) and related unsolicited AEs within 12 days of injections, and all serious AEs. Pf infection was detected by thick blood smears performed every four weeks and during febrile illness over 48 weeks. Primary vaccine efficacy (VE) endpoint was time to infection at 24 weeks. NCT02996695. FINDINGS 62 participants were enrolled in April/May 2017. Proportions of participants experiencing at least one solicited systemic AE were similar between treatment arms: 6/31 (19.4%, 95%CI 9.2-36.3) of PfSPZ-CVac recipients versus 7/31 (22.6%, 95%CI 29.2-62.2) of controls (p value = 1.000). Two/31 (6%) in each group reported related, unsolicited AEs. One unrelated death occurred. Of 59 receiving 3 immunizations per protocol, fewer vaccinees (16/29, 55.2%) became infected than controls (22/30, 73.3%). VE was 33.6% by hazard ratio (p = 0.21, 95%CI -27·9, 65·5) and 24.8% by risk ratio (p = 0.10, 95%CI -4·8, 54·3). Antibody responses to PfCSP were poor; 28% of vaccinees sero-converted. INTERPRETATION PfSPZ-CVac (CQ) was well-tolerated. The tested dosing regimen failed to significantly protect against Pf infection in this very high transmission setting. FUNDING U.S. National Institutes of Health, Sanaria. REGISTRATION NUMBER ClinicalTrials.gov identifier (NCT number): NCT02996695.
Collapse
Key Words
- ALT, alanine aminotransferase
- CHMI, Controlled Human Malaria Infection
- CQ, chloroquine
- CSP, circumsporozoite protein
- DOT, directly observed therapy
- DVI, direct venous inoculation
- ELISA, enzyme linked immunosorbent assay
- HR, hazard ratio
- Malaria vaccine
- PCR, polymerase chain reaction
- Pf, Plasmodium falciparum
- PfSPZ Vaccine
- PfSPZ-CVac
- PfSPZ-CVac, Plasmodium falciparum Sporozoite Chemoprophylaxis Vaccine
- Plasmodium falciparum
- SMC, safety monitoring committee
- SPZ, sporozoite
- Sporozoite
- TBS, thick blood smear
- VE, vaccine efficacy
Collapse
Affiliation(s)
- Drissa Coulibaly
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
- Corresponding author.
| | - Abdoulaye K. Kone
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Karim Traore
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Amadou Niangaly
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Bourema Kouriba
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Charles Arama
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Amatigue Zeguime
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Amagana Dolo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Kirsten E. Lyke
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Christopher V. Plowe
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | | | | | - Effie Nomicos
- Parasitic and International Programs Branch, Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, U. S. National Institutes of Health, Bethesda, MD, United States
| | - Gregory A. Deye
- Parasitic and International Programs Branch, Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, U. S. National Institutes of Health, Bethesda, MD, United States
| | | | | | | | | | | | - Ogobara K. Doumbo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Mahamadou A. Thera
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Matthew B. Laurens
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | |
Collapse
|
5
|
Kariuki S, Kering K, Wairimu C, Onsare R, Mbae C. Antimicrobial Resistance Rates and Surveillance in Sub-Saharan Africa: Where Are We Now? Infect Drug Resist 2022; 15:3589-3609. [PMID: 35837538 PMCID: PMC9273632 DOI: 10.2147/idr.s342753] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 06/16/2022] [Indexed: 01/03/2023] Open
Abstract
Introduction Although antimicrobials have traditionally been used to treat infections and improve health outcomes, resistance to commonly used antimicrobials has posed a major challenge. An estimated 700,000 deaths occur globally every year as a result of infections caused by antimicrobial-resistant pathogens. Antimicrobial resistance (AMR) also contributes directly to the decline in the global economy. In 2019, sub-Saharan Africa (SSA) had the highest mortality rate (23.5 deaths per 100,000) attributable to AMR compared to other regions. Methods We searched PubMed for articles relevant to AMR in pathogens in the WHO-GLASS list and in other infections of local importance in SSA. In this review, we focused on AMR rates and surveillance of AMR for these priority pathogens and some of the most encountered pathogens of public health significance. In addition, we reviewed the implementation of national action plans to mitigate against AMR in countries in SSA. Results and Discussion The SSA region is disproportionately affected by AMR, in part owing to the prevailing high levels of poverty, which result in a high burden of infectious diseases, poor regulation of antimicrobial use, and a lack of alternatives to ineffective antimicrobials. The global action plan as a strategy for prevention and combating AMR has been adopted by most countries, but fewer countries are able to fully implement country-specific action plans, and several challenges exist in many settings. Conclusion A concerted One Health approach will be required to ramp up implementation of action plans in the region. In addition to AMR surveillance, effective implementation of infection prevention and control, water, sanitation, and hygiene, and antimicrobial stewardship programs will be key cost-effective strategies in helping to tackle AMR.
Collapse
Affiliation(s)
- Samuel Kariuki
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya,Correspondence: Samuel Kariuki, Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya, Email
| | - Kelvin Kering
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Celestine Wairimu
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Robert Onsare
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Cecilia Mbae
- Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya
| |
Collapse
|
6
|
Molecular mechanisms of hematological and biochemical alterations in malaria: A review. Mol Biochem Parasitol 2021; 247:111446. [PMID: 34953384 DOI: 10.1016/j.molbiopara.2021.111446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/20/2021] [Accepted: 12/19/2021] [Indexed: 11/20/2022]
Abstract
Malaria is a dangerous disease that contributes to millions of hospital visits and hundreds of thousands of deaths, especially in children residing in sub-Saharan Africa. Although several interventions such as vector control, case detection, and treatment are already in place, there is no substantive reduction in the disease burden. Several studies in the past have reported the emergence of resistant strains of malaria parasites (MPs) and mosquitoes, and poor adherence and inaccessibility to effective antimalarial drugs as the major factors for this persistent menace of malaria infections. Moreover, victory against MP infections for many years has been hampered by an incomplete understanding of the complex nature of malaria pathogenesis. Very recent studies have identified different complex interactions and hematological alterations induced by malaria parasites. However, no studies have hybridized these alterations for a better understanding of Malaria pathogenesis. Hence, this review thoroughly discusses the molecular mechanisms of all reported hematological and biochemical alterations induced by MPs infections. Specifically, the mechanisms in which MP-infection induces anemia, thrombocytopenia, leukopenia, dyslipidemia, hypoglycemia, oxidative stress, and liver and kidney malfunctions were presented. The study also discussed how MPs evade the host's immune response and suggested strategies to limit evasion of the host's immune response to combat malaria and its complications.
Collapse
|
7
|
Immunosuppression in Malaria: Do Plasmodium falciparum Parasites Hijack the Host? Pathogens 2021; 10:pathogens10101277. [PMID: 34684226 PMCID: PMC8536967 DOI: 10.3390/pathogens10101277] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 12/13/2022] Open
Abstract
Malaria reflects not only a state of immune activation, but also a state of general immune defect or immunosuppression, of complex etiology that can last longer than the actual episode. Inhabitants of malaria-endemic regions with lifelong exposure to the parasite show an exhausted or immune regulatory profile compared to non- or minimally exposed subjects. Several studies and experiments to identify and characterize the cause of this malaria-related immunosuppression have shown that malaria suppresses humoral and cellular responses to both homologous (Plasmodium) and heterologous antigens (e.g., vaccines). However, neither the underlying mechanisms nor the relative involvement of different types of immune cells in immunosuppression during malaria is well understood. Moreover, the implication of the parasite during the different stages of the modulation of immunity has not been addressed in detail. There is growing evidence of a role of immune regulators and cellular components in malaria that may lead to immunosuppression that needs further research. In this review, we summarize the current evidence on how malaria parasites may directly and indirectly induce immunosuppression and investigate the potential role of specific cell types, effector molecules and other immunoregulatory factors.
Collapse
|
8
|
Events associated with susceptibility to invasive Salmonella enterica serovar Typhi in BALB/c mice previously infected with Plasmodium berghei ANKA. Sci Rep 2021; 11:2730. [PMID: 33526848 PMCID: PMC7851127 DOI: 10.1038/s41598-021-82330-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 01/06/2021] [Indexed: 02/02/2023] Open
Abstract
Numerous mechanisms have been proposed to explain why patients with malaria are more susceptible to bloodstream invasions by Salmonella spp., however there are still several unknown critical factors regarding the pathogenesis of coinfection. From a coinfection model, in which an S. enterica serovar Typhi (S_Typhi) was chosen to challenge mice that had been infected 24 h earlier with Plasmodium berghei ANKA (P.b_ANKA), we evaluated the influence of malaria on cytokine levels, the functional activity of femoral bone marrow-derived macrophages and neutrophils, and intestinal permeability. The cytokine profile over eight days of coinfection showed exacerbation in the cytokines MCP-1, IFNγ and TNFα in relation to the increase seen in animals with malaria. The cytokine profile was associated with a considerably reduced neutrophil and macrophage count and a prominent dysfunction, especially in ex vivo neutrophils in coinfected mice, though without bacterial modulation that could influence the invasion capacity of ex vivo S_Typhi obtained from liver macerate in non-phagocyte cells. Finally, irregularities in the integrity of intestinal tissue evidenced ruptures in the enterocyte layer, a presence of mononuclear leukocytes in the enterocyte layer, an increase of goblet cells in the enterocyte layer and a high volume of leukocyte infiltrate in the sub-mucosa were greatly increased in coinfected animals. Increases of mononuclear leukocytes in the enterocyte layer and volume of leukocyte infiltrate in the sub-mucosa were also seen in monoinfected animals with P. berghei ANKA. Our findings suggest malaria causes a disarrangement of intestinal homeostasis, exacerbation of proinflammatory cytokines and dysfunction in neutrophils that render the host susceptible to bacteremia by Salmonella spp.
Collapse
|
9
|
Piccini G, Montomoli E. Pathogenic signature of invasive non-typhoidal Salmonella in Africa: implications for vaccine development. Hum Vaccin Immunother 2020; 16:2056-2071. [PMID: 32692622 PMCID: PMC7553687 DOI: 10.1080/21645515.2020.1785791] [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] [Indexed: 11/01/2022] Open
Abstract
Invasive non-typhoidal Salmonella (iNTS) infections are a leading cause of bacteremia in Sub-Saharan Africa (sSA), thereby representing a major public health threat. Salmonella Typhimurium clade ST313 and Salmonella Enteriditis lineages associated with Western and Central/Eastern Africa are among the iNTS serovars which are of the greatest concern due to their case-fatality rate, especially in children and in the immunocompromised population. Identification of pathogen-associated features and host susceptibility factors that increase the risk for invasive non-typhoidal salmonellosis would be instrumental for the design of targeted prevention strategies, which are urgently needed given the increasing spread of multidrug-resistant iNTS in Africa. This review summarizes current knowledge of bacterial traits and host immune responses associated with iNTS infections in sSA, then discusses how this knowledge can guide vaccine development while providing a summary of vaccine candidates in preclinical and early clinical development.
Collapse
Affiliation(s)
| | - Emanuele Montomoli
- VisMederi srl , Siena, Italy.,Department of Molecular and Developmental Medicine, University of Siena , Siena, Italy
| |
Collapse
|
10
|
Kortz TB, Nyirenda J, Tembo D, Elfving K, Baltzell K, Bandawe G, Rosenthal PJ, Macfarlane SB, Mandala W, Nyirenda TS. Distinct Biomarker Profiles Distinguish Malawian Children with Malarial and Non-malarial Sepsis. Am J Trop Med Hyg 2020; 101:1424-1433. [PMID: 31595873 DOI: 10.4269/ajtmh.18-0635] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Presently, it is difficult to accurately diagnose sepsis, a common cause of childhood death in sub-Saharan Africa, in malaria-endemic areas, given the clinical and pathophysiological overlap between malarial and non-malarial sepsis. Host biomarkers can distinguish sepsis from uncomplicated fever, but are often abnormal in malaria in the absence of sepsis. To identify biomarkers that predict sepsis in a malaria-endemic setting, we retrospectively analyzed data and sera from a case-control study of febrile Malawian children (aged 6-60 months) with and without malaria who presented to a community health center in Blantyre (January-August 2016). We characterized biomarkers for 29 children with uncomplicated malaria without sepsis, 25 without malaria or sepsis, 17 with malaria and sepsis, and 16 without malaria but with sepsis. Sepsis was defined using systemic inflammatory response criteria; biomarkers (interleukin-6 [IL-6], tumor necrosis factor receptor-1, interleukin-1 β [IL-1β], interleukin-10 [IL-10], von Willebrand factor antigen-2, intercellular adhesion molecule-1, and angiopoietin-2 [Ang-2]) were measured with multiplex magnetic bead assays. IL-6, IL-1β, and IL-10 were elevated, and Ang-2 was decreased in children with malaria compared with non-malarial fever. Children with non-malarial sepsis had greatly increased IL-1β compared with the other subgroups. IL-1β best predicted sepsis, with an area under the receiver operating characteristic (AUROC) of 0.71 (95% CI: 0.57-0.85); a combined biomarker-clinical characteristics model improved prediction (AUROC of 0.77, 95% CI: 0.67-0.85). We identified a distinct biomarker profile for non-malarial sepsis and developed a sepsis prediction model. Additional clinical and biological data are necessary to further explore sepsis pathophysiology in malaria-endemic regions.
Collapse
Affiliation(s)
- Teresa B Kortz
- Department of Pediatrics, University of California, San Francisco, California.,Institute of Global Health Sciences, University of California, San Francisco, California
| | - James Nyirenda
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Department of Pathology, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Dumizulu Tembo
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Kristina Elfving
- Department of Infectious Diseases, Institution for Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Kimberly Baltzell
- Department of Family Health Care Nursing, University of California, San Francisco, California.,Institute of Global Health Sciences, University of California, San Francisco, California
| | - Gama Bandawe
- Department of Biological Sciences, Malawi University of Science and Technology, Thyolo, Malawi
| | - Philip J Rosenthal
- Department of Medicine, University of California, San Francisco, California
| | - Sarah B Macfarlane
- Department of Epidemiology and Biostatistics, University of California, San Francisco, California
| | - Wilson Mandala
- Department of Biological Sciences, Academy of Medical Sciences, Malawi University of Science and Technology, Thyolo, Malawi.,Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Tonney S Nyirenda
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Department of Pathology, College of Medicine, University of Malawi, Blantyre, Malawi
| |
Collapse
|
11
|
Abstract
Nontyphoidal salmonellae (NTS) are a major cause of invasive (iNTS) disease in sub-Saharan Africa, manifesting as bacteremia and meningitis. Available epidemiological data indicate that iNTS disease is endemic in much of the region. Antimicrobial resistance is common and case fatality rates are high. There are well-characterized clinical associations with iNTS disease, including young age, HIV infection, malaria, malnutrition, anemia, and sickle cell disease. However, the clinical presentation of iNTS disease is often with fever alone, so clinical diagnosis is impossible without blood culture confirmation. No vaccine is currently available, making this a priority area for global health research. Over the past ten years, it has emerged that iNTS disease in Africa is caused by distinct pathovars of Salmonella Typhimurium, belonging to sequence type ST313, and Salmonella Enteritidis. These are characterized by genome degradation and appear to be adapting to an invasive lifestyle. Investigation of rare patients with primary immunodeficiencies has suggested a key role for interferon gamma-mediated immunity in host defense against NTS. This concept has been supported by recent population-based host genetic studies in African children. In contrast, immunoepidemiological studies from Africa indicate an important role for antibody for protective immunity, supporting the development of antibody-inducing vaccines against iNTS disease. With candidate O-antigen-based vaccines due to enter clinical trials in the near future, research efforts should focus on understanding the relative contributions of antibody and cell-mediated immunity to protection against iNTS disease in humans.
Collapse
Affiliation(s)
| | - Calman A MacLennan
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| |
Collapse
|
12
|
Role of a single noncoding nucleotide in the evolution of an epidemic African clade of Salmonella. Proc Natl Acad Sci U S A 2018; 115:E2614-E2623. [PMID: 29487214 PMCID: PMC5856525 DOI: 10.1073/pnas.1714718115] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Invasive nontyphoidal Salmonella disease is a major and previously neglected tropical disease responsible for an estimated ∼390,000 deaths per year in Africa, largely caused by a variant of Salmonella Typhimurium called ST313. Despite the availability of >100,000 Salmonella genomes, it has proven challenging to associate individual SNPs with pathogenic traits of this dangerous bacterium. Here, we used a transcriptomic strategy to identify a single-nucleotide change in a promoter region responsible for crucial phenotypic differences of African S. Typhimurium. Our findings show that a noncoding nucleotide of the bacterial genome can have a profound effect upon the pathogenesis of infectious disease. Salmonella enterica serovar Typhimurium ST313 is a relatively newly emerged sequence type that is causing a devastating epidemic of bloodstream infections across sub-Saharan Africa. Analysis of hundreds of Salmonella genomes has revealed that ST313 is closely related to the ST19 group of S. Typhimurium that cause gastroenteritis across the world. The core genomes of ST313 and ST19 vary by only ∼1,000 SNPs. We hypothesized that the phenotypic differences that distinguish African Salmonella from ST19 are caused by certain SNPs that directly modulate the transcription of virulence genes. Here we identified 3,597 transcriptional start sites of the ST313 strain D23580, and searched for a gene-expression signature linked to pathogenesis of Salmonella. We identified a SNP in the promoter of the pgtE gene that caused high expression of the PgtE virulence factor in African S. Typhimurium, increased the degradation of the factor B component of human complement, contributed to serum resistance, and modulated virulence in the chicken infection model. We propose that high levels of PgtE expression by African S. Typhimurium ST313 promote bacterial survival and dissemination during human infection. Our finding of a functional role for an extragenic SNP shows that approaches used to deduce the evolution of virulence in bacterial pathogens should include a focus on noncoding regions of the genome.
Collapse
|
13
|
Immunological bases of increased susceptibility to invasive nontyphoidal Salmonella infection in children with malaria and anaemia. Microbes Infect 2017; 20:589-598. [PMID: 29248635 PMCID: PMC6250906 DOI: 10.1016/j.micinf.2017.11.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 11/17/2017] [Accepted: 11/20/2017] [Indexed: 01/01/2023]
Abstract
Malaria and anaemia are key underlying factors for iNTS disease in African children. Knowledge of clinical and epidemiological risk-factors for iNTS disease has not been paralleled by an in-depth knowledge of the immunobiology of the disease. Herein, we review human and animal studies on mechanisms of increased susceptibility to iNTS in children.
Collapse
|