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Thisyakorn U, Carlos J, Chotpitayasunondh T, Dien TM, Gonzales MLAM, Huong NTL, Ismail Z, Nordin MM, Ong-Lim ALT, Tantawichien T, Terumalay SD, Vu TD, Cintra O, Oladehin O. Invasive meningococcal disease in Malaysia, Philippines, Thailand, and Vietnam: An Asia-Pacific expert group perspective on current epidemiology and vaccination policies. Hum Vaccin Immunother 2022; 18:2110759. [PMID: 36084311 DOI: 10.1080/21645515.2022.2110759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Invasive meningococcal disease (IMD) imposes a significant burden on the global community due to its high case fatality rate (4-20%) and the risk of long-term sequelae for one in five survivors. An expert group meeting was held to discuss the epidemiology of IMD and immunization policies in Malaysia, Philippines, Thailand, and Vietnam. Most of these countries do not include meningococcal immunization in their routine vaccination programs, except for high-risk groups such as immunocompromised people and pilgrims. It is difficult to estimate the epidemiology of IMD in the highly diverse Asia-Pacific region, but available evidence indicate serogroup B is increasingly dominant. Disease surveillance systems differ by country. IMD is not a notifiable disease in some of them. Without an adequate surveillance system in the region, the risk and the burden of IMD might well be underestimated. With the availability of new combined meningococcal vaccines and the World Health Organization roadmap to defeat bacterial meningitis by 2030, a better understanding of the epidemiology of IMD in the Asia-Pacific region is needed.
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Affiliation(s)
- Usa Thisyakorn
- Tropical Medicine Cluster, Chulalongkorn University, Bangkok, Thailand
| | - Josefina Carlos
- University of the East Ramon Magsaysay Memorial Medical Center, Quezon City, Philippines
| | | | - Tran M Dien
- Vietnam National Children's Hospital, Hanoï, Vietnam
| | | | | | | | - Musa M Nordin
- KPJ Damansara Specialist Hospital, Selangor, Malaysia
| | - Anna Lisa T Ong-Lim
- University of the Philippines - Philippine General Hospital, Manila, Philippines
| | - Terapong Tantawichien
- Division of Infectious Diseases, Department of Medicine, Chulalongkorn University, Bangkok, Thailand
| | | | - Thiem D Vu
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
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Saito N, Solante RM, Guzman FD, Telan EO, Umipig DV, Calayo JP, Frayco CH, Lazaro JC, Ribo MR, Dimapilis AQ, Dimapilis VO, Villanueva AM, Mauhay JL, Suzuki M, Yasunami M, Koizumi N, Kitashoji E, Sakashita K, Yasuda I, Nishiyama A, Smith C, Ariyoshi K, Parry CM. A prospective observational study of community-acquired bacterial bloodstream infections in Metro Manila, the Philippines. PLoS Negl Trop Dis 2022; 16:e0010414. [PMID: 35613181 PMCID: PMC9173634 DOI: 10.1371/journal.pntd.0010414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 06/07/2022] [Accepted: 04/12/2022] [Indexed: 11/18/2022] Open
Abstract
Community-acquired bacterial bloodstream infections are caused by diverse pathogens with changing antimicrobial-resistance patterns. In low-middle income countries in Southeast Asia, where dengue fever is endemic and a leading cause of fever, limited information is available about bacterial bloodstream infections due to challenges of implementing a blood culture service. This study describes bacterial bloodstream pathogens and antimicrobial-resistance patterns in Metro Manila, the Philippines. We aimed to identify the proportion of patients with a positive blood culture, the bacteria isolated and their antimicrobial resistance patterns, and the clinical characteristics of these patients, in this dengue endemic area. We conducted a prospective observational study in a single hospital enrolling febrile patients clinically suspected of having a community-acquired bacterial bloodstream infection between 1st July 2015 and 30th June 2019. Each patient had a blood culture and additional diagnostic tests according to their clinical presentation. We enrolled 1315 patients and a significant positive blood culture was found in 77 (5.9%) including Staphylococcus aureus (n = 20), Salmonella enterica Typhi (n = 18), Escherichia coli (n = 16), Streptococcus pneumoniae (n = 3) and Burkholderia pseudomallei (n = 2). Thirty-four patients had meningococcal disease diagnosed by culture (n = 8) or blood PCR (n = 26). Additional confirmed diagnoses included leptospirosis (n = 177), dengue virus infection (n = 159) and respiratory diphtheria (n = 50). There were 79 (6.0%, 95%CI 4.8%−7.4%) patients who died within 28 days of enrollment. Patients with a positive blood culture were significantly more likely to die than patients with negative culture (15.2% vs 4.4%, P<0.01). Among S. aureus isolates, 11/20 (55%) were methicillin-resistant (MRSA) and ST30: USA1100 was dominant sequence type (88.9%). Antimicrobial-susceptibility was well preserved in S. enterica Typhi. Among hospitalized patients with clinically suspected community-acquired bacterial bloodstream infection in Metro Manila, the Philippines, 5.9% had a blood culture confirmed infection of whom 15.6% died. S. aureus, including a significant number of MRSA (USA1100 clones), S. enterica Typhi, E.coli and Neisseria meningitidis were frequently identified pathogens.
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Affiliation(s)
- Nobuo Saito
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- Department of Clinical Tropical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
- Department of Microbiology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | | | | | | | | | | | | | | | | | | | | | - Annavi M. Villanueva
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- San Lazaro Hospital, Manila, the Philippines
| | - Jaira L. Mauhay
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Motoi Suzuki
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- Department of Clinical Tropical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Michio Yasunami
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Nobuo Koizumi
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Emi Kitashoji
- Department of Clinical Tropical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Kentaro Sakashita
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Ikkoh Yasuda
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- Department of Clinical Tropical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Akira Nishiyama
- Department of Clinical Tropical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Chris Smith
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Koya Ariyoshi
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- Department of Clinical Tropical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
- * E-mail: (KA); (CMP)
| | - Christopher M. Parry
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail: (KA); (CMP)
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McMillan M, Marshall HS, Richmond P. 4CMenB vaccine and its role in preventing transmission and inducing herd immunity. Expert Rev Vaccines 2021; 21:103-114. [PMID: 34747302 DOI: 10.1080/14760584.2022.2003708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION : Vaccination is the most effective method of protecting people from invasive meningococcal disease (IMD). Of all the capsular groups, B is the most common cause of invasive meningococcal disease in many parts of the world. Despite this, adolescent meningococcal B vaccine programs have not been implemented globally, partly due to the lack of evidence for herd immunity afforded by meningococcal B vaccines. AREAS COVERED This review aims to synthesise the available evidence on recombinant 4CMenB vaccines' ability to reduce pharyngeal carriage and therefore provide indirect (herd) immunity against IMD. EXPERT OPINION There is some evidence that the 4CMenB vaccine may induce cross-protection against non-B carriage of meningococci. However, the overall body of evidence does not support a clinically significant reduction in carriage of disease-associated or group B meningococci following 4CMenB vaccination. No additional cost-benefit from herd immunity effects should be included when modelling the cost-effectiveness of 4CMenB vaccine programs against group B IMD. 4CMenB immunisation programs should focus on direct (individual) protection for groups at greatest risk of meningococcal disease. Future meningococcal B and combination vaccines being developed should consider the impact of the vaccine on carriage as part of their clinical evaluation.
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Affiliation(s)
- Mark McMillan
- Vaccinology and Immunology Research Trials Unit, Women's and Children's Health Network, Adelaide, South Australia, Australia.,Robinson Research Institute and Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, Australia
| | - Helen S Marshall
- Vaccinology and Immunology Research Trials Unit, Women's and Children's Health Network, Adelaide, South Australia, Australia.,Robinson Research Institute and Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, Australia
| | - Peter Richmond
- Division of Paediatrics, School of Medicine, University of Western Australia, Department of General Paediatrics and Immunology, Perth Children's Hospital.,Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kid's Institute, Perth, Western Australia
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Sharma S, Acharya J, Caugant DA, Aryal S, Banjara MR, Ghimire P, Singh A. Meningococcal Carriage among Household Contacts of Patients with Invasive Meningococcal Disease in Kathmandu, Nepal: A Longitudinal Study. Pathogens 2021; 10:pathogens10070781. [PMID: 34206153 PMCID: PMC8308540 DOI: 10.3390/pathogens10070781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/11/2021] [Accepted: 06/15/2021] [Indexed: 11/24/2022] Open
Abstract
Because asymptomatic carriers are key source of transmission, information on meningococcal carriage in the community provides a scientific basis for appropriate preventive/control strategies. This longitudinal study (January 2017–December 2019) aimed to estimate carriage rate of meningococci among household contacts of meningococcal meningitis cases within Kathmandu Valley, Nepal. Throat swab samples were collected at first visit from each person in households, twice a month for up to 2 months and subsequently on a monthly basis for a further 4 months. Altogether, 1125 throat samples were processed by conventional culture for the identification of meningococci. To the best of our knowledge, this is the first longitudinal study on meningococcal carriage in Nepal. The meningococcal carriage rate among household contacts was 15%. All carriers were aged 19 years or older. There was no statistically significant gender difference. The duration of carriage was 60 days. Twenty of 36 isolates belonged to serogroup A, and 16 were non-serogroupable (NG). Serogroups isolated from the same individuals did not change within the follow-up period. All meningococcal isolates over the past 38 years in Nepal that have been reported in previous studies have belonged to serogroup A. The detection of NG meningococcal isolates in apparently healthy household contacts clearly indicates the importance of vigilance through surveillance and periodic in-depth studies.
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Affiliation(s)
- Supriya Sharma
- Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu 44600, Nepal; (M.R.B.); (P.G.); (A.S.)
- Correspondence: ; Tel.: +977-98-4150-8496
| | - Jyoti Acharya
- National Public Health Laboratory, Teku, Kathmandu 44600, Nepal;
| | - Dominique A. Caugant
- WHO Collaborating Centre for Reference and Research on Meningococci, Norwegian Institute of Public Health, 0213 Oslo, Norway;
| | | | - Megha Raj Banjara
- Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu 44600, Nepal; (M.R.B.); (P.G.); (A.S.)
| | - Prakash Ghimire
- Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu 44600, Nepal; (M.R.B.); (P.G.); (A.S.)
| | - Anjana Singh
- Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu 44600, Nepal; (M.R.B.); (P.G.); (A.S.)
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Aye AMM, Bai X, Borrow R, Bory S, Carlos J, Caugant DA, Chiou CS, Dai VTT, Dinleyici EC, Ghimire P, Handryastuti S, Heo JY, Jennison A, Kamiya H, Tonnii Sia L, Lucidarme J, Marshall H, Putri ND, Saha S, Shao Z, Sim JHC, Smith V, Taha MK, Van Thanh P, Thisyakorn U, Tshering K, Vázquez J, Veeraraghavan B, Yezli S, Zhu B. Meningococcal disease surveillance in the Asia-Pacific region (2020): The global meningococcal initiative. J Infect 2020; 81:698-711. [PMID: 32730999 DOI: 10.1016/j.jinf.2020.07.025] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/17/2020] [Accepted: 07/24/2020] [Indexed: 12/20/2022]
Abstract
The degree of surveillance data and control strategies for invasive meningococcal disease (IMD) varies across the Asia-Pacific region. IMD cases are often reported throughout the region, but the disease is not notifiable in some countries, including Myanmar, Bangladesh and Malaysia. Although there remains a paucity of data from many countries, specific nations have introduced additional surveillance measures. The incidence of IMD is low and similar across the represented countries (<0.2 cases per 100,000 persons per year), with the predominant serogroups of Neisseria meningitidis being B, W and Y, although serogroups A and X are present in some areas. Resistance to ciprofloxacin is also of concern, with the close monitoring of antibiotic-resistant clonal complexes (e.g., cc4821) being a priority. Meningococcal vaccination is only included in a few National Immunization Programs, but is recommended for high-risk groups, including travellers (such as pilgrims) and people with complement deficiencies or human immunodeficiency virus (HIV). Both polysaccharide and conjugate vaccines form part of recommendations. However, cost and misconceptions remain limiting factors in vaccine uptake, despite conjugate vaccines preventing the acquisition of carriage.
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Affiliation(s)
| | - Xilian Bai
- Meningococcal Reference Unit, Public Health England, Manchester Royal Infirmary, Manchester M13 9WZ, UK.
| | - Ray Borrow
- Meningococcal Reference Unit, Public Health England, Manchester Royal Infirmary, Manchester M13 9WZ, UK.
| | | | - Josefina Carlos
- University of the East Ramon Magsaysay Memorial Medical Center, Quezon City, Philippines
| | | | | | - Vo Thi Trang Dai
- Department of Microbiology and Immunology, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Viet Nam
| | | | | | | | - Jung Yeon Heo
- Department of Infectious Diseases, Ajou University School of Medicine, Suwon, South Korea.
| | | | - Hajime Kamiya
- National Institute of Infectious Diseases, Tokyo, Japan
| | | | - Jay Lucidarme
- Meningococcal Reference Unit, Public Health England, Manchester Royal Infirmary, Manchester M13 9WZ, UK.
| | - Helen Marshall
- Robinson Research Institute and department of Paediatrics, Adelaide Medical School, The University of Adelaide, Adelaide, Australia.
| | - Nina Dwi Putri
- Dr Cipto Mangunkusumo National Central Hospital, Jakarta, Indonesia
| | - Senjuti Saha
- Child Health Research Foundation, Mohammadpur, Dhaka1207, Bangladesh.
| | - Zhujun Shao
- National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
| | | | - Vinny Smith
- Meningitis Research Foundation, Bristol, UK.
| | | | - Phan Van Thanh
- Department of Microbiology and Immunology, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Viet Nam
| | - Usa Thisyakorn
- Tropical Medicine Cluster, Chulalongkorn University, Bangkok, Thailand
| | - Kinley Tshering
- Jigme Dorji Wangchuck National Referral Hospital, Thimpu, Bhutan
| | - Julio Vázquez
- National Reference Laboratory for Meningococci, Institute of Health Carlos III, Spain.
| | | | - Saber Yezli
- Global Center for Mass Gatherings Medicine, Saudi Arabia
| | - Bingqing Zhu
- National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
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Serra L, Presa J, Christensen H, Trotter C. Carriage of Neisseria Meningitidis in Low and Middle Income Countries of the Americas and Asia: A Review of the Literature. Infect Dis Ther 2020; 9:209-240. [PMID: 32242281 PMCID: PMC7237586 DOI: 10.1007/s40121-020-00291-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION Meningococcal colonization, or carriage, can progress to invasive meningococcal disease, a serious public health concern, with rapid progression of disease and severe consequences if left untreated. Information on meningococcal carriage and epidemiology in low/middle income American and Asian countries remains sparse. These data are crucial to ensure that appropriate preventive strategies such as vaccination can be implemented in these regions. The goal of this study was to summarize the Neisseria meningitidis carriage literature in low and middle income countries of the Americas and Asia. METHODS Target countries were categorized as low and middle income according to the International Monetary Fund classification of low income/developing economies and middle income/emerging market economies, respectively. A PubMed search identified English-language publications that examined carriage in these countries. Studies reporting the epidemiology of N. meningitidis carriage or assessing risk factors for carriage were included. RESULTS Fourteen studies from the Americas [Brazil (n = 7), Chile (n = 3), and Colombia, Cuba, Mexico, and Paraguay (n = 1 each)] and nine from Asia [China (n = 2), India (n = 3), and Malaysia, Nepal, Philippines, and Thailand (n = 1 each)] were identified; an additional Cuban study from the authors' files was also included. Studies were not identified in many target countries, and substantial diversity was observed among study methodologies, populations, and time periods, thereby limiting comparison between studies. The carriage rate in the Americas ranged from 1.6% to 9.9% and from 1.4% to 14.2% in Asia. Consistent risk factors for carriage were not identified. CONCLUSIONS There is a lack of comprehensive and contemporary information on meningococcal carriage in low and medium income countries of the Americas and Asia. Future carriage studies should incorporate larger representative populations, a wider age range, and additional countries to improve our understanding of meningococcal epidemiology and disease control.
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Affiliation(s)
- Lidia Serra
- Pfizer Vaccine Medical Development, Scientific and Clinical Affairs, Collegeville, PA, USA.
| | - Jessica Presa
- Pfizer Vaccines, Medical and Scientific Affairs, Collegeville, PA, USA
| | - Hannah Christensen
- Bristol Medical School, Population Health Sciences, University of Bristol, Clifton, UK
| | - Caroline Trotter
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
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Sadeghi M, Ahmadrajabi R, Dehesh T, Saffari F. Prevalence of meningococcal carriage among male university students living in dormitories in Kerman, southeast of Iran. Pathog Glob Health 2018; 112:329-333. [PMID: 30156971 DOI: 10.1080/20477724.2018.1514138] [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] [Indexed: 01/19/2023] Open
Abstract
Neisseria meningitidis is an important causative agent of bacterial meningitis. The nasopharynx is the only known reservoir of this organism. Although the relationship between carriage and invasive disease is not completely understood, asymptomatic meningococcal carriers are considered as the most important sources for causing strains of disease. Living in closed and overcrowded places such as university dormitories can increase the carriage rate and meningococcal disease. This cross-sectional study was conducted to determine the prevalence of N. meningitidis carriers among male students living in three dormitories affiliated with Kerman University of Medical Sciences (Kerman, Iran). Nasopharyngeal swab was taken from all participants recruited in the study. Conventional microbiological tests were performed for isolation and detection of the organism. The amplification of crgA gene was used to confirm the identity of isolates. Molecular serogrouping was used to detect the six most frequent serotypes. The overall carriage rate was 6.8% (23/335). The capsular type of these isolates was in determinate (56.5%) or of serogroup C (43.5%). Multivariate logistic regression analysis revealed that cigarette smoking was significantly associated with meningococcal carriage (OR = 5.02; p = 0.01). Additionally, using univariate regression analysis, a significant association was found between water pipe smoking and carriage (p = 0.018). The rate of meningococcal carriage among male students in the studied population was lower as compared to other high-risk group (freshmen conscripts) in Iran. University students should be aware of the consequences of cigarette and water pipe smoking as risk factors in meningococcal carriage.
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Affiliation(s)
- Mohammad Sadeghi
- a Department of Microbiology and Virology, School of Medicine , Kerman University of Medical Sciences , Kerman , Iran
| | - Roya Ahmadrajabi
- a Department of Microbiology and Virology, School of Medicine , Kerman University of Medical Sciences , Kerman , Iran
| | - Tania Dehesh
- b Department of Epidemiology and Biostatistics, School of Public Health , Kerman University of Medical Sciences , Kerman , Iran
| | - Fereshteh Saffari
- a Department of Microbiology and Virology, School of Medicine , Kerman University of Medical Sciences , Kerman , Iran
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Rubilar PS, Barra GN, Gabastou JM, Alarcón P, Araya P, Hormazábal JC, Fernandez J. Increase of Neisseria meningitidis W:cc11 invasive disease in Chile has no correlation with carriage in adolescents. PLoS One 2018; 13:e0193572. [PMID: 29518095 PMCID: PMC5843251 DOI: 10.1371/journal.pone.0193572] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 02/14/2018] [Indexed: 12/15/2022] Open
Abstract
Neisseria meningitidis is a human exclusive pathogen that can lead to invasive meningococcal disease or may be carried in the upper respiratory tract without symptoms. The relationship between carriage and disease remains poorly understood but it is widely accepted that decreasing carriage by immunization should lead to a reduction of invasive cases. Latin America has experienced an increased incidence of serogroup W invasive cases of Neisseria meningitidis in the last decade. Specifically in Chile, despite low total incidence of invasive cases, serogroup W has become predominant since 2011 and has been associated with elevated mortality. Expecting to gain insight into the epidemiology of this disease, this study has used molecular typing schemes to compare Neisseria meningitidis isolates causing invasive disease with those isolates collected from adolescent carriers during the same period in Chile. A lower carriage of the serogroup W clonal complex ST-11/ET37 than expected was found; whereas, the same clonal complex accounted for 66% of total invasive meningococcal disease cases in the country that year. A high diversity of PorA variable regions and fHbp peptides was also ascertained in the carrier isolates compared to the invasive ones. According to the results shown here, the elevated number of serogroup W invasive cases in our country cannot be explained by a rise of carriage of pathogenic isolates. Overall, this study supports the idea that some strains, as W:cc11 found in Chile, possess an enhanced virulence to invade the host. Notwithstanding hypervirulence, this strain has not caused an epidemic in Chile. Finally, as genetic transfer occurs often, close surveillance of Neisseria meningitidis strains causing disease, and particularly hypervirulent W:cc11, should be kept as a priority in our country, in order to prepare the best response to face genetic changes that could lead to enhanced fitness of this pathogen.
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Affiliation(s)
- Paulina S. Rubilar
- Sub-Department of Molecular Genetics, Biomedical Department, Public Health Institute, Santiago, Chile
- Pan American Health Organization/ World Health Organization, Washington, D.C., United States of America
| | - Gisselle N. Barra
- Sub-Department of Molecular Genetics, Biomedical Department, Public Health Institute, Santiago, Chile
| | - Jean-Marc Gabastou
- Pan American Health Organization/ World Health Organization, Washington, D.C., United States of America
| | - Pedro Alarcón
- Bacteriology section, Infectious Diseases Sub-Department, Biomedical Department, Public Health Institute, Santiago, Chile
| | - Pamela Araya
- Bacteriology section, Infectious Diseases Sub-Department, Biomedical Department, Public Health Institute, Santiago, Chile
| | - Juan C. Hormazábal
- Infectious diseases sub-Department, Biomedical laboratory department, Public Health Institute, Santiago, Chile
| | - Jorge Fernandez
- Sub-Department of Molecular Genetics, Biomedical Department, Public Health Institute, Santiago, Chile
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