Christopher M Parry

Liverpool School of Tropical Medicine, Liverpool, England, United Kingdom

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Publications (101)646.99 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Ventilator associated pneumonia (VAP) is a serious hospital acquired infection that affects up to 30% of intubated patients on intensive care units (ICUs) worldwide. The aetiology of VAP is highly variable and can differ between countries, national provinces, and even between different wards in same hospital. We aimed to understand and document changes in the causative agents of VAP and their corresponding antimicrobial susceptibility profiles retrospectively over an 11 year-period in a major infectious disease hospital in southern Vietnam. Our analysis outlines a significant shift from Pseudomonas aeruginosa to Acinetobacter baumannii as the most prevalent bacteria isolated from tracheal aspirates in patients with VAP in this setting. Antimicrobial resistance was extensive across all bacterial species and we found a dramatic proportional annual increase in carbapenem resistant Acinetobacter baumannii over a three-year period from 2008 (annual trend; OR 1.656, p=0.010). We further investigated the emergence of carbapenem resistant Acinetobacter baumannii, finding a blaNDM-1 positive isolate and a specific clone containing blaOXA23 and blaOXA51 that was positively associated with an upsurge in the isolation of this pathogen. Our work outlines the emergence of carbapenem resistant clone of Acinetobacter baumannii in Vietnam, and highlights a worrying trend in antimicrobial resistant Gram-negative bacteria circulating in this infectious disease hospital.
    Journal of medical microbiology. 07/2014;
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    ABSTRACT: Septic arthritis is a rare complication of typhoid fever. A 12-year-old boy without pre-existing disease attended a paediatric hospital in Cambodia with fever and left hip pain. A hip synovial fluid aspirate grew multidrug-resistant Salmonella enterica ser. Typhi with intermediate susceptibility to ciprofloxacin. Arthrotomy, 2 weeks of intravenous ceftriaxone and 4 weeks of oral azithromycin led to resolution of symptoms. The optimum management of septic arthritis in drug-resistant typhoid is undefined.
    Paediatrics and international child health. 04/2014;
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    ABSTRACT: Typhoid fever is a systemic infection caused by the bacterium Salmonella enterica serovar Typhi. Age, sex, prolonged duration of illness, and infection with an antimicrobial resistant organism have been proposed risk factors for the development of severe disease or fatality in typhoid fever. We analysed clinical data from 581 patients consecutively admitted with culture confirmed typhoid fever to two hospitals in Vietnam during two periods in 1993-1995 and 1997-1999. These periods spanned a change in the antimicrobial resistance phenotypes of the infecting organisms i.e. fully susceptible to standard antimicrobials, resistance to chloramphenicol, ampicillin and trimethoprim-sulphamethoxazole (multidrug resistant, MDR), and intermediate susceptibility to ciprofloxacin (nalidixic acid resistant). Age, sex, duration of illness prior to admission, hospital location and the presence of MDR or intermediate ciprofloxacin susceptibility in the infecting organism were examined by logistic regression analysis to identify factors independently associated with severe typhoid at the time of hospital admission. The prevalence of severe typhoid was 15.5% (90/581) and included: gastrointestinal bleeding (43; 7.4%); hepatitis (29; 5.0%); encephalopathy (16; 2.8%); myocarditis (12; 2.1%); intestinal perforation (6; 1.0%); haemodynamic shock (5; 0.9%), and death (3; 0.5%). Severe disease was more common with increasing age, in those with a longer duration of illness and in patients infected with an organism exhibiting intermediate susceptibility to ciprofloxacin. Notably an MDR phenotype was not associated with severe disease. Severe disease was independently associated with infection with an organism with an intermediate susceptibility to ciprofloxacin (AOR 1.90; 95% CI 1.18-3.07; p = 0.009) and male sex (AOR 1.61 (1.00-2.57; p = 0.035). In this group of patients hospitalised with typhoid fever infection with an organism with intermediate susceptibility to ciprofloxacin was independently associated with disease severity. During this period many patients were being treated with fluoroquinolones prior to hospital admission. Ciprofloxacin and ofloxacin should be used with caution in patients infected with S. Typhi that have intermediate susceptibility to ciprofloxacin.
    BMC Infectious Diseases 02/2014; 14(1):73. · 3.03 Impact Factor
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    ABSTRACT: To estimate the prevalence of Group A beta-haemolytic streptococcus (GAS) and non-GAS infections among children with acute pharyngotonsillitis in Aden, Yemen, to evaluate the value of a rapid diagnostic test and the McIsaac score for patient management in this setting and to determine the occurrence of emm genotypes among a subset of GAS isolated from children with acute pharyngotonsillitis and a history of acute rheumatic fever (ARF) or rheumatic heart disease (RHD). Group A beta-haemolytic streptococcus infections in school-aged children with acute pharyngotonsillitis in Aden, Yemen, were diagnosed by a rapid GAS antigen detection test (RADT) and/or GAS culture from a throat swab. The RADT value and the McIsaac screening score for patient management were evaluated. The emm genotype of a subset of GAS isolates was determined. Group A beta-haemolytic streptococcus pharyngotonsillitis was diagnosed in 287/691 (41.5%; 95% CI 37.8-45.3) children. Group B, Group C and Group G beta-haemolytic streptococci were isolated from 4.3% children. The RADT had a sensitivity of 238/258 (92.2%) and specificity of 404/423 (95.5%) against GAS culture. A McIsaac score of ≥4 had a sensitivity of 93% and a specificity of 82% for confirmed GAS infection. The emm genotypes in 21 GAS isolates from children with pharyngitis and a history of ARF and confirmed RHD were emm87 (11), emm12 (6), emm28 (3) and emm5 (1). This study demonstrates a very high prevalence of GAS infections in Yemeni children and the value of the RADT and the McIsaac score in this setting. More extensive emm genotyping is necessary to understand the local epidemiology of circulating strains.
    Tropical Medicine & International Health 01/2014; · 2.94 Impact Factor
  • Stephen Baker, Abhilasha Karkey, Christopher Parry
    The Lancet Global Health. 01/2014; 2(4):e195–e196.
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    Christopher M Parry, Buddha Basnyat, John A Crump
    Expert Review of Anticancer Therapy 12/2013; 11(12):1259-61. · 3.22 Impact Factor
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    ABSTRACT: Rapid diagnostic tests are needed for typhoid fever (TF) diagnosis in febrile children in endemic areas. Five hundred children admitted to the hospital in Cambodia between 2009 and 2010 with documented fever (≥ 38°C) were investigated using blood cultures (BCs), Salmonella Typhi/Paratyphi A real-time polymerase chain reactions (PCRs), and a Typhoid immunoglobulin M flow assays (IgMFAs). Test performance was determined by conventional methods and Bayesian latent class modeling. There were 32 cases of TF (10 BC- and PCR-positive cases, 14 BC-positive and PCR-negative cases, and 8 BC-negative and PCR-positive cases). IgMFA sensitivity was 59.4% (95% confidence interval = 41-76), and specificity WAS 97.8% (95% confidence interval = 96-99). The model estimate sensitivity for BC was 81.0% (95% credible interval = 54-99). The model estimate sensitivity for PCR was 37.8% (95% credible interval = 26-55), with a specificity of 98.2% (95% credible interval = 97-99). The model estimate sensitivity for IgMFA (≥ 2+) was 77.9% (95% credible interval = 58-90), with a specificity of 97.5% (95% credible interval = 95-100). The model estimates of IgMFA sensitivity and specificity were comparable with BCs and better than estimates using conventional analysis.
    The American journal of tropical medicine and hygiene 11/2013; · 2.53 Impact Factor
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    ABSTRACT: Shigella sonnei is a human-adapted pathogen that is emerging globally as the dominant agent of bacterial dysentery. To investigate local establishment, we sequenced the genomes of 263 Vietnamese S. sonnei isolated over 15 y. Our data show that S. sonnei was introduced into Vietnam in the 1980s and has undergone localized clonal expansion, punctuated by genomic fixation events through periodic selective sweeps. We uncover geographical spread, spatially restricted frontier populations, and convergent evolution through local gene pool sampling. This work provides a unique, high-resolution insight into the microevolution of a pioneering human pathogen during its establishment in a new host population.
    Proceedings of the National Academy of Sciences 09/2013; · 9.81 Impact Factor
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    ABSTRACT: This study aimed to define the molecular basis of co-trimoxazole resistance in Malawian pneumococci under the dual selective pressure of widespread co-trimoxazole and sulfadoxine/pyrimethamine use. We measured the trimethoprim and sulfamethoxazole MICs and analysed folA and folP nucleotide and translated amino acid sequences for 143 pneumococci isolated from carriage and invasive disease in Malawi (2002-08). Pneumococci were highly resistant to both trimethoprim and sulfamethoxazole (96%, 137/143). Sulfamethoxazole-resistant isolates showed a 3 or 6 bp insertion in the sulphonamide-binding site of folP. The trimethoprim-resistant isolates fell into three genotypic groups based on dihydrofolate reductase (encoded by folA) mutations: Ile-100-Leu (10%), the Ile-100-Leu substitution together with a residue 92 substitution (56%) and those with a novel uncharacterized resistance genotype (34%). The nucleotide sequence divergence and dN/dS of folA and folP remained stable from 2004 onwards. S. pneumoniae exhibit almost universal co-trimoxazole resistance in vitro and in silico that we believe is driven by extensive co-trimoxazole and sulfadoxine/pyrimethamine use. More than one-third of pneumococci employ a novel mechanism of co-trimoxazole resistance. Resistance has now reached a point of stabilizing evolution. The use of co-trimoxazole to prevent pneumococcal infection in HIV/AIDS patients in sub-Saharan Africa should be re-evaluated.
    Journal of Antimicrobial Chemotherapy 09/2013; · 5.34 Impact Factor
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    ABSTRACT: Pediatric bacterial bloodstream infections (BSIs) are a major cause of morbidity and mortality worldwide. Epidemiological data from resource-limited settings in southeast Asia, such as Cambodia, are sparse but have important implications for treatment and public health strategies. We retrospectively investigated BSI in children at a pediatric hospital and its satellite clinic in Siem Reap, Cambodia, from January 1, 2007, to July 31, 2011. The range of bacterial pathogens and their antimicrobial susceptibility patterns were analyzed in conjunction with demographic, clinical and outcome data. Of 7682 blood cultures with results (99.9% of cultures taken), 606 (7.9%) episodes of BSI were identified in 588 children. The incidence of BSI increased from 14 to 50/1000 admissions (P < 0.001); this was associated with an increased sampling rate. Most BSI were community acquired (89.1%). Common pathogens included Salmonella Typhi (22.8% of all isolates), Staphylococcus aureus (12.2%), Streptococcus pneumoniae (10.0%), Klebsiella pneumoniae (6.4%) and Escherichia coli (6.3%). 21.5% of BSI were caused by a diverse group of uncommon organisms, the majority of which were environmental Gram-negative species. No Listeria monocytogenes or Group B streptococcal BSI were identified. Antimicrobial resistance, particularly among the Enterobacteriaceae, was common. Overall mortality was substantial (19.0%), higher in neonates (36.9%) and independently associated with meningitis/meningoencephalitis and K. pneumoniae infection. BSI is a common problem in Cambodian children attending hospital and associated with significant mortality. Further studies are needed to clarify the epidemiology of neonatal sepsis, the contribution of atypical organisms and the epidemiology of pneumococcal disease before the introduction of vaccine.
    The Pediatric Infectious Disease Journal 07/2013; 32(7):e272-6. · 3.57 Impact Factor
  • European Journal of Intensive Care Medicine 05/2013; · 5.17 Impact Factor
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    ABSTRACT: The First National Workshop on Antibiotic Resistance in Cambodia was organised by the Cambodian Ministry of Health with support from several national and international partner institutions. It brought together policy-makers, clinicians, pharmacists, laboratory technicians and other professionals dealing with the problems of bacterial infection and antibiotic resistance across the country. Antibiotic resistance data from starting up and experienced laboratories were presented, showing high rates of resistance in key pathogens to most antibiotics currently available in Cambodia, e.g. 70–90% multidrug resistance and 70–80% decreased ciprofloxacin susceptibility in Salmonella enterica serovar Typhi, 20–40% meticillin resistance rates in Staphylococcus aureus and 30–50% extended-spectrum β-lactamase production in Escherichia coli. A five-point plan was discussed, which included initiatives from government and non-governmental partners, focusing on rational prescribing, clinical practice guidelines, improved laboratory services, infection prevention and enhanced education at all levels. Implementation, however challenging, is a priority given the high levels of resistance seen in key pathogens and the overall health needs in the country.
    Journal of Global Antimicrobial Resistance. 03/2013; 1(1):31–34.
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    ABSTRACT: BACKGROUND: The clinical significance of bacteraemia secondary to non-typhoidal Salmonella (NTS) gastroenteritis in hospitalised adults is uncertain. METHODS: Adults admitted to a hospital in Liverpool, UK, with NTS gastroenteritis were identified using hospital discharge data and laboratory records. Patients with known HIV infection were excluded. Risk factors for a complicated or fatal course were determined. RESULTS: Between 1982 and 2006 inclusive, 633 adults were identified. Serovars causing infection included Enteritidis (46.6%), Typhimurium (27.6%) and Virchow (4.9%). A blood culture was taken in 364 (57.5%) patients who were generally sicker than those who were not cultured. Bacteraemia was detected in 63 (17.3%) patients who had blood cultures taken (63/633 (10.0%) of all patients). Bacteraemia was more common in those aged >= 65 years (p < 0.001) and in those aged < 65 years who had an underlying chronic disease. A complicated course occurred in 91 (25.0%) patients who had had a blood culture taken (148/633 (23.4%) of all patients). Independent factors associated with a complicated or fatal course among the patients investigated with a blood culture were bacteraemia (Adjusted Odds Ratio 5.34, 95% CI 2.86--9.95); new onset confusion or coma (AOR 4.80, 95% CI 1.91--12.07); prolonged symptoms prior to admission (AOR 2.48, 95%CI 1.44--4.27); dehydration (AOR1.90, 95% CI 1.07--3.38); and absence of fever (AOR 0.56, 95% CI 0.32--0.95). The 30 day attributable case fatality for all patients was 1.5%. CONCLUSIONS: In this study secondary bacteraemia, as well as other clinical factors, was independently associated with a complicated or fatal course in non-HIV infected adults admitted to hospital with NTS gastroenteritis.
    BMC Infectious Diseases 02/2013; 13(1):107. · 3.03 Impact Factor
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    ABSTRACT: Febrile illnesses are pre-eminent contributors to morbidity and mortality among children in South-East Asia but the causes are poorly understood. We determined the causes of fever in children hospitalised in Siem Reap province, Cambodia. A one-year prospective study of febrile children admitted to Angkor Hospital for Children, Siem Reap. Demographic, clinical, laboratory and outcome data were comprehensively analysed. Between October 12(th) 2009 and October 12(th) 2010 there were 1225 episodes of febrile illness in 1180 children. Median (IQR) age was 2.0 (0.8-6.4) years, with 850 (69%) episodes in children <5 years. Common microbiological diagnoses were dengue virus (16.2%), scrub typhus (7.8%), and Japanese encephalitis virus (5.8%). 76 (6.3%) episodes had culture-proven bloodstream infection, including Salmonella enterica serovar Typhi (22 isolates, 1.8%), Streptococcus pneumoniae (13, 1.1%), Escherichia coli (8, 0.7%), Haemophilus influenzae (7, 0.6%), Staphylococcus aureus (6, 0.5%) and Burkholderia pseudomallei (6, 0.5%). There were 69 deaths (5.6%), including those due to clinically diagnosed pneumonia (19), dengue virus (5), and melioidosis (4). 10 of 69 (14.5%) deaths were associated with culture-proven bloodstream infection in logistic regression analyses (odds ratio for mortality 3.4, 95% CI 1.6-6.9). Antimicrobial resistance was prevalent, particularly in S. enterica Typhi, (where 90% of isolates were resistant to ciprofloxacin, and 86% were multi-drug resistant). Comorbid undernutrition was present in 44% of episodes and a major risk factor for acute mortality (OR 2.1, 95% CI 1.1-4.2), as were HIV infection and cardiac disease. We identified a microbiological cause of fever in almost 50% of episodes in this large study of community-acquired febrile illness in hospitalized children in Cambodia. The range of pathogens, antimicrobial susceptibility, and co-morbidities associated with mortality described will be of use in the development of rational guidelines for infectious disease treatment and control in Cambodia and South-East Asia.
    PLoS ONE 01/2013; 8(4):e60634. · 3.73 Impact Factor
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    ABSTRACT: Infections with Salmonella enterica serovar Typhi isolates that are multidrug resistant (MDR: resistant to chloramphenicol, ampicillin, trimethoprim-sulphamethoxazole) with intermediate ciprofloxacin susceptibility are widespread in Asia but there is little information from Cambodia. We studied invasive salmonellosis in children at a paediatric hospital in Siem Reap, Cambodia. Between 2007 and 2011 Salmonella was isolated from a blood culture in 162 children. There were 151 children with enteric fever, including 148 serovar Typhi and three serovar Paratyphi A infections, and 11 children with a non-typhoidal Salmonella infection. Of the 148 serovar Typhi isolates 126 (85%) were MDR and 133 (90%) had intermediate ciprofloxacin susceptibility. Inpatient antimicrobial treatment was ceftriaxone alone or initial ceftriaxone followed by a step-down to oral ciprofloxacin or azithromycin. Complications developed in 37/128 (29%) children admitted with enteric fever and two (1.6%) died. There was one confirmed relapse. In a sample of 102 serovar Typhi strains genotyped by investigation of a subset of single nucleotide polymorphisms, 98 (96%) were the H58 haplotype, the majority of which had the common serine to phenylalanine substitution at codon 83 in the DNA gyrase. We conclude that antimicrobial-resistant enteric fever is common in Cambodian children and therapeutic options are limited.
    Transactions of the Royal Society of Tropical Medicine and Hygiene 10/2012; · 1.82 Impact Factor
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    ABSTRACT: A highly invasive form of non-typhoidal Salmonella (iNTS) disease has recently been documented in many countries in sub-Saharan Africa. The most common Salmonella enterica serovar causing this disease is Typhimurium (Salmonella Typhimurium). We applied whole-genome sequence-based phylogenetic methods to define the population structure of sub-Saharan African invasive Salmonella Typhimurium isolates and compared these to global Salmonella Typhimurium populations. Notably, the vast majority of sub-Saharan invasive Salmonella Typhimurium isolates fell within two closely related, highly clustered phylogenetic lineages that we estimate emerged independently ∼52 and ∼35 years ago in close temporal association with the current HIV pandemic. Clonal replacement of isolates from lineage I by those from lineage II was potentially influenced by the use of chloramphenicol for the treatment of iNTS disease. Our analysis suggests that iNTS disease is in part an epidemic in sub-Saharan Africa caused by highly related Salmonella Typhimurium lineages that may have occupied new niches associated with a compromised human population and antibiotic treatment.
    Nature Genetics 09/2012; · 35.21 Impact Factor
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    ABSTRACT: There are limited data on osteoarticular infections from resource-limited settings in Asia. A retrospective study of patients presenting to the Angkor Hospital for Children, Cambodia, January 2007-July 2011, identified 81 cases (28% monoarticular septic arthritis, 51% single-limb osteomyelitis and 15% multisite infections). The incidence was 13.8/100 000 hospital attendances. The median age was 7.3 years, with a male/female ratio of 1.9:1; 35% presented within 5 days of symptom onset (median 7 days). Staphylococcus aureus was cultured in 29 (36%) cases (52% of culture-positive cases); one isolate was methicillin-resistant (MRSA). Median duration of antimicrobial treatment was 29 days (interquartile range 21-43); rates of surgical intervention were 96%, and 46% of children had sequelae, with one fatality. In this setting osteoarticular infections are relatively common with high rates of surgical intervention and sequelae. Staphylococcus aureus is the commonest culturable cause, but methicillin-resistant S. aureus is not a major problem, unlike in other Asian centers.
    Journal of Tropical Pediatrics 09/2012; · 1.01 Impact Factor
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    ABSTRACT: Chromobacterium violaceum infection is rarely described in Southeast Asian children, which may be due partly to the lack of access to adequate microbiology facilities in many areas. This case report describes the first documented case to occur in a Cambodian child. An awareness of the disease and its manifestations is important as treatment can be difficult and may require prolonged courses of antimicrobials and surgery.
    Tropical Doctor 07/2012; 42(3):178-9. · 0.61 Impact Factor
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    ABSTRACT: We studied gastrointestinal parasites in symptomatic Cambodian children attending a provincial hospital in Siem Reap, Cambodia between 2006 and 2011. A total of 16 372 faecal samples were examined by direct microscopy. Parasites were detected in 3121 (19.1%) samples and most common were Giardia lamblia (8.0% of samples; 47.6% disease episodes), hookworm (5.1%; 30.3%) and Strongyloides stercoralis (2.6%; 15.6%). The proportion of infected children increased, and the number of disease episodes effectively treated with a single dose of mebendazole decreased, over the 5-year period.
    Journal of Tropical Pediatrics 06/2012; · 1.01 Impact Factor
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    ABSTRACT: The causes of suppurative parotitis in Cambodian children are not known. We describe 39 cases at the Angkor Hospital for Children, Siem Reap, between January 2007 and July 2011 (0.07/1000 hospital attendances). The median age was 5.7 years with no neonates affected. Burkholderia pseudomallei was cultured in 29 (74%) cases. No deaths occurred; 1 child developed facial nerve palsy.
    The Pediatric Infectious Disease Journal 04/2012; 31(8):865-8. · 3.57 Impact Factor

Publication Stats

3k Citations
646.99 Total Impact Points


  • 2010–2014
    • Liverpool School of Tropical Medicine
      • Child and Reproductive Health Group
      Liverpool, England, United Kingdom
  • 2013
    • University of Melbourne
      • Department of Biochemistry and Molecular Biology
      Melbourne, Victoria, Australia
  • 2010–2013
    • Patan Academy of Health Sciences
      Kantipura, Central Region, Nepal
  • 2006–2013
    • Royal Liverpool and Broadgreen University Hospitals NHS Trust
      • • Tropical and Infectious Disease Unit
      • • Department of Ophthalmology
      Liverpool, England, United Kingdom
  • 2003–2013
    • University of Liverpool
      • Department of Clinical Infection, Microbiology & Immunology
      Liverpool, England, United Kingdom
  • 2011–2012
    • Angkor Hospital for Children
      Siemrãp, Siem Reap, Cambodia
    • Malawi-Liverpool-Wellcome Trust Clinical Research Programme
      Kapeni, Southern Region, Malawi
    • Duke University Medical Center
      • Department of Medicine
      Durham, NC, United States
  • 2002–2012
    • Oxford University Clinical Research Unit
      Thành phố Hồ Chí Minh, Ho Chi Minh City, Vietnam
  • 1998–2011
    • University of Oxford
      • • Centre for Tropical Medicine
      • • Nuffield Department of Clinical Medicine
      Oxford, England, United Kingdom
  • 1997–2011
    • Hospital for Tropical Diseases, Ho Chi Minh City
      Thành phố Hồ Chí Minh, Ho Chi Minh City, Vietnam
  • 2001–2008
    • Oxford University Hospitals NHS Trust
      Oxford, England, United Kingdom
  • 2005
    • Wellcome Trust Sanger Institute
      Cambridge, England, United Kingdom
  • 2000–2005
    • Imperial College London
      • Centre for Molecular Microbiology and Infection
      London, ENG, United Kingdom
    • Hue College of Medicine and Pharmacy
      Huế, Thừa Thiên-Huế, Vietnam
  • 2004
    • University of California, San Francisco
      • Center for AIDS Prevention Studies
      San Francisco, CA, United States
  • 1997–2000
    • Cho Ray Hospital
      Thành phố Hồ Chí Minh, Ho Chi Minh City, Vietnam