A large outbreak of shigellosis commencing in an internally displaced population, Papua New Guinea, 2013
- Benny, Edwin, Mesere, Kelly, Pavlin, Boris, Yakam, Logan, Ford, Rebecca, Yoannes, Mition, Kisa, Debbie, Abdad, Mohammad, Menda, Lincoln, Greenhill, Andrew, Horwood, Paul
- Authors: Benny, Edwin , Mesere, Kelly , Pavlin, Boris , Yakam, Logan , Ford, Rebecca , Yoannes, Mition , Kisa, Debbie , Abdad, Mohammad , Menda, Lincoln , Greenhill, Andrew , Horwood, Paul
- Date: 2014
- Type: Text , Journal article
- Relation: Western Pacific surveillance and response journal : WPSAR Vol. 5, no. 3 (2014), p. 18-21
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- Description: OBJECTIVE: The objective of this study was to investigate a large outbreak of shigellosis in Papua New Guinea that began in a camp for internally displaced persons before spreading throughout the general community. METHODS: Outbreak mitigation strategies were implemented in the affected area to curtail the spread of the disease. Data were collected from the surveillance system and analysed by time, place and person. Rectal swab samples were tested by standard culture methods and real-time polymerase chain reaction to determine the etiology of the outbreak. RESULTS: Laboratory analysis at two independent institutions established that the outbreak was caused by Shigella sp., with one strain further characterized as Shigella flexneri serotype 2. Approximately 1200 suspected cases of shigellosis were reported in a two-month period from two townships in Morobe Province, Papua New Guinea. The outbreak resulted in at least five deaths, all in young children. DISCUSSION: This outbreak of shigellosis highlights the threat of enteric diseases to vulnerable populations such as internally displaced persons in Papua New Guinea, as has been observed in other global settings.
- Authors: Benny, Edwin , Mesere, Kelly , Pavlin, Boris , Yakam, Logan , Ford, Rebecca , Yoannes, Mition , Kisa, Debbie , Abdad, Mohammad , Menda, Lincoln , Greenhill, Andrew , Horwood, Paul
- Date: 2014
- Type: Text , Journal article
- Relation: Western Pacific surveillance and response journal : WPSAR Vol. 5, no. 3 (2014), p. 18-21
- Full Text:
- Reviewed:
- Description: OBJECTIVE: The objective of this study was to investigate a large outbreak of shigellosis in Papua New Guinea that began in a camp for internally displaced persons before spreading throughout the general community. METHODS: Outbreak mitigation strategies were implemented in the affected area to curtail the spread of the disease. Data were collected from the surveillance system and analysed by time, place and person. Rectal swab samples were tested by standard culture methods and real-time polymerase chain reaction to determine the etiology of the outbreak. RESULTS: Laboratory analysis at two independent institutions established that the outbreak was caused by Shigella sp., with one strain further characterized as Shigella flexneri serotype 2. Approximately 1200 suspected cases of shigellosis were reported in a two-month period from two townships in Morobe Province, Papua New Guinea. The outbreak resulted in at least five deaths, all in young children. DISCUSSION: This outbreak of shigellosis highlights the threat of enteric diseases to vulnerable populations such as internally displaced persons in Papua New Guinea, as has been observed in other global settings.
Antimicrobial sensitivity trends and virulence genes in Shigella spp. from the Oceania region
- Malau, Elisheba, Ford, Rebecca, Valcanis, Mary, Jennison, Amy, Mosse, Jenny, Bean, David, Yoannes, Mition, Pomat, William, Horwood, Paul, Greenhill, Andrew
- Authors: Malau, Elisheba , Ford, Rebecca , Valcanis, Mary , Jennison, Amy , Mosse, Jenny , Bean, David , Yoannes, Mition , Pomat, William , Horwood, Paul , Greenhill, Andrew
- Date: 2018
- Type: Text , Journal article
- Relation: Infection, Genetics and Evolution Vol. 64, no. (2018), p. 52-56
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- Description: Shigella is a common cause of diarrhoea in Papua New Guinea (PNG) and other Oceania countries. However, little is known about the strains causing infection. Archived Shigella isolates (n = 72) were obtained from research laboratories in PNG and reference laboratories in Australia. Shigella virulence genes were detected by PCR, and antimicrobial susceptibility was determined by disk diffusion. The ipaH virulence gene was present in all 72 isolates. The prevalence of other virulence genes was variable, with ial, invE, ipaBCD, sen/ospD3 and virF present in 60% of isolates and set1A and set1B genes present in 42% of isolates. Most S. flexneri isolates contained genes encoding enterotoxin 1 and/or enterotoxin 2. Resistance to antibiotics was common, with 51/72 isolates resistant to 2–4 antimicrobials. A greater proportion of bacteria isolated since 2010 (relative to pre-2010 isolates) were resistant to commonly used antibiotics such as ampicillin, chloramphenicol, tetracycline, and trimethoprim-sulfamethoxazole; suggesting that antimicrobial resistance (AMR) in Shigella is increasing over time in the Oceania region. There is a need for improved knowledge regarding Shigella circulation in the Oceania region and further monitoring of AMR patterns. © 2018 Elsevier B.V.
- Authors: Malau, Elisheba , Ford, Rebecca , Valcanis, Mary , Jennison, Amy , Mosse, Jenny , Bean, David , Yoannes, Mition , Pomat, William , Horwood, Paul , Greenhill, Andrew
- Date: 2018
- Type: Text , Journal article
- Relation: Infection, Genetics and Evolution Vol. 64, no. (2018), p. 52-56
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- Description: Shigella is a common cause of diarrhoea in Papua New Guinea (PNG) and other Oceania countries. However, little is known about the strains causing infection. Archived Shigella isolates (n = 72) were obtained from research laboratories in PNG and reference laboratories in Australia. Shigella virulence genes were detected by PCR, and antimicrobial susceptibility was determined by disk diffusion. The ipaH virulence gene was present in all 72 isolates. The prevalence of other virulence genes was variable, with ial, invE, ipaBCD, sen/ospD3 and virF present in 60% of isolates and set1A and set1B genes present in 42% of isolates. Most S. flexneri isolates contained genes encoding enterotoxin 1 and/or enterotoxin 2. Resistance to antibiotics was common, with 51/72 isolates resistant to 2–4 antimicrobials. A greater proportion of bacteria isolated since 2010 (relative to pre-2010 isolates) were resistant to commonly used antibiotics such as ampicillin, chloramphenicol, tetracycline, and trimethoprim-sulfamethoxazole; suggesting that antimicrobial resistance (AMR) in Shigella is increasing over time in the Oceania region. There is a need for improved knowledge regarding Shigella circulation in the Oceania region and further monitoring of AMR patterns. © 2018 Elsevier B.V.
Distinct Streptococcus pneumoniae cause invasive disease in Papua New Guinea
- Mellor, Kate, Lo, Stephanie, Yoannes, Mition, Michael, Audrey, Orami, Tilda, Greenhill, Andrew, Breiman, Robert, Hawkins, Paulina, McGee, Lesley, Bentley, Stephen, Ford, Rebecca, Lehmann, Deborah
- Authors: Mellor, Kate , Lo, Stephanie , Yoannes, Mition , Michael, Audrey , Orami, Tilda , Greenhill, Andrew , Breiman, Robert , Hawkins, Paulina , McGee, Lesley , Bentley, Stephen , Ford, Rebecca , Lehmann, Deborah
- Date: 2022
- Type: Text , Journal article
- Relation: Microbial Genomics Vol. 8, no. 7 (2022), p.
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- Description: Streptococcus pneumoniae is a key contributor to childhood morbidity and mortality in Papua New Guinea (PNG). For the first time, whole genome sequencing of 174 isolates has enabled detailed characterisation of diverse S. pneumoniae causing invasive disease in young children in PNG, 1989-2014. This study captures the baseline S. pneumoniae population prior to the introduction of 13-valent pneumococcal conjugate vaccine (PCV13) into the national childhood immunisation programme in 2014. Relationships amongst lineages, serotypes and antimicrobial resistance traits were characterised, and the population was viewed in the context of a global collection of isolates. The analyses highlighted adiverse S. pneumoniae population associated with invasive disease in PNG, with 45 unique Global Pneumococcal Sequence Clusters (GPSCs) observed amongst the 174 isolates reflecting multiple lineages observed in PNG that have not been identified in other geographic locations. The majority of isolates were from children with meningitis, of which 52% (n=72) expressed non-PCV13 serotypes. Over a third of isolates were predicted to be resistant to at least one antimicrobial. PCV13 serotype isolates had 10.1 times the odds of being multidrug-resistant (MDR) compared to non-vaccine serotype isolates, and no isolates with GPSCs unique to PNG were MDR. Serotype 2 was the most commonly identified serotype; we identified a highly clonal cluster of serotype 2 isolates unique to PNG, and a distinct second cluster indicative of long-distance transmission. Ongoing surveillance, including whole-genome sequencing, is needed to ascertain the impact of the national PCV13 programme upon the S. pneumoniae population, including serotype replacement and antimicrobial resistance traits. © 2022 The Authors.
- Authors: Mellor, Kate , Lo, Stephanie , Yoannes, Mition , Michael, Audrey , Orami, Tilda , Greenhill, Andrew , Breiman, Robert , Hawkins, Paulina , McGee, Lesley , Bentley, Stephen , Ford, Rebecca , Lehmann, Deborah
- Date: 2022
- Type: Text , Journal article
- Relation: Microbial Genomics Vol. 8, no. 7 (2022), p.
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- Description: Streptococcus pneumoniae is a key contributor to childhood morbidity and mortality in Papua New Guinea (PNG). For the first time, whole genome sequencing of 174 isolates has enabled detailed characterisation of diverse S. pneumoniae causing invasive disease in young children in PNG, 1989-2014. This study captures the baseline S. pneumoniae population prior to the introduction of 13-valent pneumococcal conjugate vaccine (PCV13) into the national childhood immunisation programme in 2014. Relationships amongst lineages, serotypes and antimicrobial resistance traits were characterised, and the population was viewed in the context of a global collection of isolates. The analyses highlighted adiverse S. pneumoniae population associated with invasive disease in PNG, with 45 unique Global Pneumococcal Sequence Clusters (GPSCs) observed amongst the 174 isolates reflecting multiple lineages observed in PNG that have not been identified in other geographic locations. The majority of isolates were from children with meningitis, of which 52% (n=72) expressed non-PCV13 serotypes. Over a third of isolates were predicted to be resistant to at least one antimicrobial. PCV13 serotype isolates had 10.1 times the odds of being multidrug-resistant (MDR) compared to non-vaccine serotype isolates, and no isolates with GPSCs unique to PNG were MDR. Serotype 2 was the most commonly identified serotype; we identified a highly clonal cluster of serotype 2 isolates unique to PNG, and a distinct second cluster indicative of long-distance transmission. Ongoing surveillance, including whole-genome sequencing, is needed to ascertain the impact of the national PCV13 programme upon the S. pneumoniae population, including serotype replacement and antimicrobial resistance traits. © 2022 The Authors.
Limited impact of neonatal or early infant schedules of 7-valent pneumococcal conjugate vaccination on nasopharyngeal carriage of Streptococcus pneumoniae in Papua New Guinean children: A randomized controlled trial
- Aho, Celestine, Michael, Audrey, Yoannes, Mition, Greenhill, Andrew, Jacoby, Peter, Reeder, John, Pomat, William, Saleu, Gerard, Namuigi, Pioto, Phuanukoonnon, Suparat, Smith-Vaughan, Heidi, Leach, Amanda, Richmond, Peter, Lehmann, Deborah
- Authors: Aho, Celestine , Michael, Audrey , Yoannes, Mition , Greenhill, Andrew , Jacoby, Peter , Reeder, John , Pomat, William , Saleu, Gerard , Namuigi, Pioto , Phuanukoonnon, Suparat , Smith-Vaughan, Heidi , Leach, Amanda , Richmond, Peter , Lehmann, Deborah
- Date: 2016
- Type: Text , Journal article
- Relation: Vaccine Reports Vol. 6, no. (2016), p. 36-43
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- Description: Streptococcus pneumoniae is a leading cause of pneumonia, the most common cause of childhood death. Papua New Guinean children experience high rates of nasopharyngeal pneumococcal colonization within weeks of birth, predisposing them to pneumococcal disease. In a trial to determine the safety and immunogenicity of early infant vaccination with 7-valent pneumococcal conjugate vaccine (7vPCV), we investigated the impact of early schedules on pneumococcal carriage. Infants were randomized at birth to receive 7vPCV in a 0–1–2-month (n = 101) or a 1–2–3-month (n = 105) schedule or no 7vPCV (n = 106). All children received 23-valent pneumococcal polysaccharide vaccine at age 9 months. We cultured nasopharyngeal swabs (NPS) collected at ages 1, 2, 3, 4 weeks and 3, 9, 18 months, and middle ear discharge if present. Pneumococcal serotypes were identified by the Quellung reaction. A total of 1761 NPS were cultured. The prevalence of pneumococcal carriage was 22% at 1 week of age, rising to 80% by age 3 months and remained >70% thereafter, with high-density carriage in 42% of pneumococcuspositive samples. We identified 63 different serotypes; 43% of isolates from controls were 13vPCV serotypes. There were no significant differences in 7vPCV serotype carriage between 7vPCV recipients and controls at any age (22% vs. 31% at 9 months, p = 0.2). At age 9 months the prevalence of non-7vPCV carriage was 17% higher in 7vPCV recipients (48%) than in controls (25%, p = 0.02). More non-7vPCV serotypes were isolated from ear discharge in 16 7vPCV recipients than from 4 controls (48% vs. 25%, p = 0.13). The limited impact of neonatal or accelerated infant 7vPCV schedules on vaccine serotype carriage is probably due to the early onset of dense carriage of a broad range of pneumococcal serotypes. While serotype-independent pneumococcal vaccines are needed in high-risk populations, the underlying environmental factors and sources of infection must be investigated.
- Authors: Aho, Celestine , Michael, Audrey , Yoannes, Mition , Greenhill, Andrew , Jacoby, Peter , Reeder, John , Pomat, William , Saleu, Gerard , Namuigi, Pioto , Phuanukoonnon, Suparat , Smith-Vaughan, Heidi , Leach, Amanda , Richmond, Peter , Lehmann, Deborah
- Date: 2016
- Type: Text , Journal article
- Relation: Vaccine Reports Vol. 6, no. (2016), p. 36-43
- Full Text:
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- Description: Streptococcus pneumoniae is a leading cause of pneumonia, the most common cause of childhood death. Papua New Guinean children experience high rates of nasopharyngeal pneumococcal colonization within weeks of birth, predisposing them to pneumococcal disease. In a trial to determine the safety and immunogenicity of early infant vaccination with 7-valent pneumococcal conjugate vaccine (7vPCV), we investigated the impact of early schedules on pneumococcal carriage. Infants were randomized at birth to receive 7vPCV in a 0–1–2-month (n = 101) or a 1–2–3-month (n = 105) schedule or no 7vPCV (n = 106). All children received 23-valent pneumococcal polysaccharide vaccine at age 9 months. We cultured nasopharyngeal swabs (NPS) collected at ages 1, 2, 3, 4 weeks and 3, 9, 18 months, and middle ear discharge if present. Pneumococcal serotypes were identified by the Quellung reaction. A total of 1761 NPS were cultured. The prevalence of pneumococcal carriage was 22% at 1 week of age, rising to 80% by age 3 months and remained >70% thereafter, with high-density carriage in 42% of pneumococcuspositive samples. We identified 63 different serotypes; 43% of isolates from controls were 13vPCV serotypes. There were no significant differences in 7vPCV serotype carriage between 7vPCV recipients and controls at any age (22% vs. 31% at 9 months, p = 0.2). At age 9 months the prevalence of non-7vPCV carriage was 17% higher in 7vPCV recipients (48%) than in controls (25%, p = 0.02). More non-7vPCV serotypes were isolated from ear discharge in 16 7vPCV recipients than from 4 controls (48% vs. 25%, p = 0.13). The limited impact of neonatal or accelerated infant 7vPCV schedules on vaccine serotype carriage is probably due to the early onset of dense carriage of a broad range of pneumococcal serotypes. While serotype-independent pneumococcal vaccines are needed in high-risk populations, the underlying environmental factors and sources of infection must be investigated.
Streptococcus pneumoniae and Haemophilus influenzae in paediatric meningitis patients at Goroka General Hospital, Papua New Guinea : Serotype distribution and antimicrobial susceptibility in the pre-vaccine era
- Greenhill, Andrew, Phuanukoonnon, Suparat, Michael, Audrey, Yoannes, Mition, Orami, Tilda, Smith, Helen, Murphy, Denise, Blyth, Christopher, Reeder, John, Siba, Peter, Pomat, William, Lehmann, Deborah
- Authors: Greenhill, Andrew , Phuanukoonnon, Suparat , Michael, Audrey , Yoannes, Mition , Orami, Tilda , Smith, Helen , Murphy, Denise , Blyth, Christopher , Reeder, John , Siba, Peter , Pomat, William , Lehmann, Deborah
- Date: 2015
- Type: Text , Journal article
- Relation: BMC Infectious Diseases Vol. 15, no. 485 (2015), p. 1-8
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- Description: Background: Bacterial meningitis remains an important infection globally, with the greatest burden in children in low-income settings, including Papua New Guinea (PNG). We present serotype, antimicrobial susceptibility and outcome data from paediatric meningitis patients prior to introduction of Haemophilus influenzae type b (Hib) and pneumococcal conjugate vaccines (PCVs) in PNG, providing a baseline for evaluation of immunisation programs. Methods: Cerebrospinal fluid (CSF) was collected from children admitted to Goroka General Hospital with suspected meningitis between 1996 and 2005. Culture and sensitivity was conducted, and pneumococci and H. influenzae were serotyped. Laboratory findings were linked to clinical outcomes. Results: We enrolled 1884 children. A recognised pathogen was identified in 375 children (19.9%). Streptococcus pneumoniae (n = 180) and Hib (n = 153) accounted for 88.8% of pathogens isolated. 24 different pneumococcal serogroups were identified; non-PCV types 2, 24 and 46 accounted for 31.6% of pneumococcal meningitis. 10- and 13-valent PCVs would cover 44.1% and 45.4% of pneumococcal meningitis respectively. Pneumococcal isolates were commonly resistant to penicillin (21.5%) and 23% of Hib isolates were simultaneously resistant to ampicillin, co-trimoxazole and chloramphenicol. The case fatality rate in patients with a recognised bacterial pathogen was 13.4% compared to 8.5% in culture-negative patients. Conclusions: If implemented in routine expanded programme of immunisation (EPI) with high coverage, current PCVs could prevent almost half of pneumococcal meningitis cases. Given the diversity of circulating serotypes in PNG serotype replacement is of concern. Ongoing surveillance is imperative to monitor the impact of vaccines. In the longer term vaccines providing broader protection against pneumococcal meningitis will be needed. © 2015 Greenhill et al.
- Authors: Greenhill, Andrew , Phuanukoonnon, Suparat , Michael, Audrey , Yoannes, Mition , Orami, Tilda , Smith, Helen , Murphy, Denise , Blyth, Christopher , Reeder, John , Siba, Peter , Pomat, William , Lehmann, Deborah
- Date: 2015
- Type: Text , Journal article
- Relation: BMC Infectious Diseases Vol. 15, no. 485 (2015), p. 1-8
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- Description: Background: Bacterial meningitis remains an important infection globally, with the greatest burden in children in low-income settings, including Papua New Guinea (PNG). We present serotype, antimicrobial susceptibility and outcome data from paediatric meningitis patients prior to introduction of Haemophilus influenzae type b (Hib) and pneumococcal conjugate vaccines (PCVs) in PNG, providing a baseline for evaluation of immunisation programs. Methods: Cerebrospinal fluid (CSF) was collected from children admitted to Goroka General Hospital with suspected meningitis between 1996 and 2005. Culture and sensitivity was conducted, and pneumococci and H. influenzae were serotyped. Laboratory findings were linked to clinical outcomes. Results: We enrolled 1884 children. A recognised pathogen was identified in 375 children (19.9%). Streptococcus pneumoniae (n = 180) and Hib (n = 153) accounted for 88.8% of pathogens isolated. 24 different pneumococcal serogroups were identified; non-PCV types 2, 24 and 46 accounted for 31.6% of pneumococcal meningitis. 10- and 13-valent PCVs would cover 44.1% and 45.4% of pneumococcal meningitis respectively. Pneumococcal isolates were commonly resistant to penicillin (21.5%) and 23% of Hib isolates were simultaneously resistant to ampicillin, co-trimoxazole and chloramphenicol. The case fatality rate in patients with a recognised bacterial pathogen was 13.4% compared to 8.5% in culture-negative patients. Conclusions: If implemented in routine expanded programme of immunisation (EPI) with high coverage, current PCVs could prevent almost half of pneumococcal meningitis cases. Given the diversity of circulating serotypes in PNG serotype replacement is of concern. Ongoing surveillance is imperative to monitor the impact of vaccines. In the longer term vaccines providing broader protection against pneumococcal meningitis will be needed. © 2015 Greenhill et al.
Whole genome sequence analysis of Salmonella Typhi in Papua New Guinea reveals an established population of genotype 2.1.7 sensitive to antimicrobials
- Dyson, Zoe, Malau, Elisheba, Horwood, Paul, Ford, Rebecca, Siba, Valentine, Yoannes, Mition, Pomat, William, Passey, Megan, Judd, Louise, Ingle, Danielle, Williamson, Deborah, Dougan, Gordon, Greenhill, Andrew, Holt, Kathryn
- Authors: Dyson, Zoe , Malau, Elisheba , Horwood, Paul , Ford, Rebecca , Siba, Valentine , Yoannes, Mition , Pomat, William , Passey, Megan , Judd, Louise , Ingle, Danielle , Williamson, Deborah , Dougan, Gordon , Greenhill, Andrew , Holt, Kathryn
- Date: 2022
- Type: Text , Journal article
- Relation: PLoS Neglected Tropical Diseases Vol. 16, no. 3 (2022), p.
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- Description: Background Typhoid fever, a systemic infection caused by Salmonella enterica serovar Typhi, remains a considerable public health threat in impoverished regions within many low-and middle-income settings. However, we still lack a detailed understanding of the emergence, population structure, molecular mechanisms of antimicrobial resistance (AMR), and transmission dynamics of S. Typhi across many settings, particularly throughout the Asia-Pacific islands. Here we present a comprehensive whole genome sequence (WGS) based overview of S. Typhi populations circulating in Papua New Guinea (PNG) over 30 years. Principle findings Bioinformatic analysis of 86 S. Typhi isolates collected between 1980–2010 demonstrated that the population structure of PNG is dominated by a single genotype (2.1.7) that appears to have emerged in the Indonesian archipelago in the mid-twentieth century with minimal evidence of inter-country transmission. Genotypic and phenotypic data demonstrated that the PNG S. Typhi population appears to be susceptible to former first line drugs for treating typhoid fever (chloramphenicol, ampicillin and co-trimoxazole), as well as fluoroquinolones, third generation cephalosporins, and macrolides. PNG genotype 2.1.7 was genetically con-served, with very few deletions, and no evidence of plasmid or prophage acquisition. Genetic variation among this population was attributed to either single point mutations, or homologous recombination adjacent to repetitive ribosomal RNA operons. Significance Antimicrobials remain an effective option for the treatment of typhoid fever in PNG, along with other intervention strategies including improvements to water, sanitation and hygiene (WaSH) related infrastructure and potentially the introduction of Vi-conjugate vaccines. However, continued genomic surveillance is warranted to monitor for the emergence of AMR within local populations, or the introduction of AMR associated genotypes of S. Typhi in this setting. © The Authors.
- Authors: Dyson, Zoe , Malau, Elisheba , Horwood, Paul , Ford, Rebecca , Siba, Valentine , Yoannes, Mition , Pomat, William , Passey, Megan , Judd, Louise , Ingle, Danielle , Williamson, Deborah , Dougan, Gordon , Greenhill, Andrew , Holt, Kathryn
- Date: 2022
- Type: Text , Journal article
- Relation: PLoS Neglected Tropical Diseases Vol. 16, no. 3 (2022), p.
- Full Text:
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- Description: Background Typhoid fever, a systemic infection caused by Salmonella enterica serovar Typhi, remains a considerable public health threat in impoverished regions within many low-and middle-income settings. However, we still lack a detailed understanding of the emergence, population structure, molecular mechanisms of antimicrobial resistance (AMR), and transmission dynamics of S. Typhi across many settings, particularly throughout the Asia-Pacific islands. Here we present a comprehensive whole genome sequence (WGS) based overview of S. Typhi populations circulating in Papua New Guinea (PNG) over 30 years. Principle findings Bioinformatic analysis of 86 S. Typhi isolates collected between 1980–2010 demonstrated that the population structure of PNG is dominated by a single genotype (2.1.7) that appears to have emerged in the Indonesian archipelago in the mid-twentieth century with minimal evidence of inter-country transmission. Genotypic and phenotypic data demonstrated that the PNG S. Typhi population appears to be susceptible to former first line drugs for treating typhoid fever (chloramphenicol, ampicillin and co-trimoxazole), as well as fluoroquinolones, third generation cephalosporins, and macrolides. PNG genotype 2.1.7 was genetically con-served, with very few deletions, and no evidence of plasmid or prophage acquisition. Genetic variation among this population was attributed to either single point mutations, or homologous recombination adjacent to repetitive ribosomal RNA operons. Significance Antimicrobials remain an effective option for the treatment of typhoid fever in PNG, along with other intervention strategies including improvements to water, sanitation and hygiene (WaSH) related infrastructure and potentially the introduction of Vi-conjugate vaccines. However, continued genomic surveillance is warranted to monitor for the emergence of AMR within local populations, or the introduction of AMR associated genotypes of S. Typhi in this setting. © The Authors.
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