Dr Ivo Elliott

Research Area: Clinical Epidemiology
Scientific Themes: Immunology & Infectious Disease and Tropical Medicine & Global Health
Keywords: ecology, epidemiology, population genetics and rickettsial diseases
Web Links:
DPhil fieldwork in Northern Thailand. © David Maurice Smith

DPhil fieldwork in Northern Thailand. © David Maurice Smith

Dr Elliott is studying for a DPhil in Clinical Medicine at the University of Oxford and is an Honorary Consultant Physician at the John Radcliffe Hospital in Oxford. He currently holds a Wellcome Trust Researching Training Fellowship.

His research is investigating the clinical epidemiology and ecology of scrub typhus in humans, chiggers and rodents. Dr Elliott's interests include the ecology and epidemiology of infectious diseases, population genetics, GIS mapping and the effects of climate and habitat change on human disease risk.

Name Department Institution Country
Professor Paul Newton Tropical Medicine Oxford University, Vientiane Laos
Dr Rory Bowden High Throughput Genomics Wellcome Trust Centre for Human genetics United Kingdom
Professor Nicholas PJ Day FMedSci FRCP Tropical Medicine Oxford University, Bangkok Thailand
Professor Daniel H Paris Tropical Medicine Oxford University, Bangkok Thailand
Liz Batty Bioinformatics Wellcome Trust Centre for Human genetics United Kingdom
Serge Morand CNRS-CIRAD Montpellier France
Ben Makepeace Institute of Infection & Global Health University of Liverpool United Kingdom
Manivanh L, Pierret A, Rattanavong S, Kounnavongsa O, Buisson Y, Elliott I, Maeght J-L, Xayyathip K, Silisouk J, Vongsouvath M et al. 2017. Burkholderia pseudomallei in a lowland rice paddy: seasonal changes and influence of soil depth and physico-chemical properties. Sci Rep, 7 (1), pp. 3031. | Show Abstract | Read more

Melioidosis, a severe infection with the environmental bacterium Burkholderia pseudomallei, is being recognised increasingly frequently. What determines its uneven distribution within endemic areas is poorly understood. We cultured soil from a rice field in Laos for B. pseudomallei at different depths on 4 occasions over a 13-month period. We also measured physical and chemical parameters in order to identify associated characteristics. Overall, 195 of 653 samples (29.7%) yielded B. pseudomallei. A higher prevalence of B. pseudomallei was found at soil depths greater than the 30 cm currently recommended for B. pseudomallei environmental sampling. B. pseudomallei was associated with a high soil water content and low total nitrogen, carbon and organic matter content. Our results suggested that a sampling grid of 25 five metre square quadrats (i.e. 25 × 25 m) should be sufficient to detect B. pseudomallei at a given location if samples are taken at a soil depth of at least 60 cm. However, culture of B. pseudomallei in environmental samples is difficult and liable to variation. Future studies should both rely on molecular approaches and address the micro-heterogeneity of soil when investigating physico-chemical associations with the presence of B. pseudomallei.

Stoesser N, Xayaheuang S, Vongsouvath M, Phommasone K, Elliott I, Del Ojo Elias C, Crook DW, Newton PN, Buisson Y, Lee SJ, Dance DAB. 2015. Colonization with Enterobacteriaceae producing ESBLs in children attending pre-school childcare facilities in the Lao People's Democratic Republic. J Antimicrob Chemother, 70 (6), pp. 1893-1897. | Show Abstract | Read more

OBJECTIVES: Intestinal carriage constitutes an important reservoir of antimicrobial-resistant bacteria, with some of the highest rates reported from Asia. Antibiotic resistance has been little studied in Laos, where some antibiotics are available without restriction, but others such as carbapenems are not available. PATIENTS AND METHODS: We collected stools from 397 healthy children in 12 randomly selected pre-school childcare facilities in and around Vientiane. Colonization with ESBL-producing Enterobacteriaceae (ESBLE) and carbapenemase-producing Enterobacteriaceae (CPE) was detected using a disc diffusion screening test and ESBLE were characterized using WGS. Risk factor data were collected by questionnaire. RESULTS: Ninety-two children (23%) were colonized with ESBLE, mainly Escherichia coli carrying blaCTX-M and Klebsiella pneumoniae carrying blaSHV or blaCTX-M, which were frequently resistant to multiple antibiotic classes. Although residence in Vientiane Capital, foreign travel, higher maternal level of education, antibiotic use in the preceding 3 months and attending a childcare facility with a 'good' level of hygiene were all associated with ESBLE colonization on univariable analysis, a significant association remained only for antibiotic use when a stepwise approach was used with a multivariate random-effects model. WGS analysis suggested transmission in both childcare facilities and community settings. CONCLUSIONS: The high prevalence of paediatric colonization with ESBLE in Laos, one of the highest reported in Asia, is probably the result of inappropriate antibiotic use. Paediatric colonization with CPE was not identified in this study, but it is important to continue to monitor the spread of antibiotic-resistant Enterobacteriaceae in Laos.

Elliott I, Patel T, Shah J, Venkatesan P. 2014. West-African trypanosomiasis in a returned traveller from Ghana: an unusual cause of progressive neurological decline Case Reports, 2014 (aug14 1), pp. bcr2014204451-bcr2014204451. | Read more

Elliott I, Mayxay M, Yeuichaixong S, Lee SJ, Newton PN. 2014. The practice and clinical implications of tablet splitting in international health. Tropical medicine & international health : TM & IH, 19 (7), pp. 754-760. | Show Abstract | Read more

Tablet splitting is frequently performed to facilitate correct dosing, but the practice and implications in low-income settings have rarely been discussed. We selected eight drugs, with narrow therapeutic indices or critical dosages, frequently divided in the Lao PDR (Laos). These were split, by common techniques used in Laos, by four nurses and four laypersons. The mean percentage deviation from the theoretical expected weight and weight loss of divided tablets/capsules were recorded. Five of eight study drugs failed, on splitting, to meet European Pharmacopoeia recommendations for tablet weight deviation from the expected weight of tablet/capsule halves with 10% deviating by more than 25%. There was a significant difference in splitting accuracy between nurses and laypersons (P = 0.027). Coated and unscored tablets were less accurately split than uncoated (P = 0.03 and 0.0019 for each half) and scored (0.0001 for both halves) tablets. These findings have potential clinical implications on treatment outcome and the development of antimicrobial resistance. Investment by drug companies in a wider range of dosage units, particularly for narrow therapeutic index and critical dosage medicines, is strongly recommended. © 2014 The Authors. Tropical Medicine & International Health published by John Wiley & Sons Ltd.

Smit PW, Elliott I, Peeling RW, Mabey D, Newton PN. 2014. An overview of the clinical use of filter paper in the diagnosis of tropical diseases. Am J Trop Med Hyg, 90 (2), pp. 195-210. | Show Abstract | Read more

Tropical infectious diseases diagnosis and surveillance are often hampered by difficulties of sample collection and transportation. Filter paper potentially provides a useful medium to help overcome such problems. We reviewed the literature on the use of filter paper, focusing on the evaluation of nucleic acid and serological assays for diagnosis of infectious diseases using dried blood spots (DBS) compared with recognized gold standards. We reviewed 296 eligible studies and included 101 studies evaluating DBS and 192 studies on other aspects of filter paper use. We also discuss the use of filter paper with other body fluids and for tropical veterinary medicine. In general, DBS perform with sensitivities and specificities similar or only slightly inferior to gold standard sample types. However, important problems were revealed with the uncritical use of DBS, inappropriate statistical analysis, and lack of standardized methodology. DBS have great potential to empower healthcare workers by making laboratory-based diagnostic tests more readily accessible, but additional and more rigorous research is needed.

Elliott I, Dittrich S, Paris D, Sengduanphachanh A, Phoumin P, Newton PN. 2013. The use of dried cerebrospinal fluid filter paper spots as a substrate for PCR diagnosis of the aetiology of bacterial meningitis in the Lao PDR Clinical Microbiology and Infection, 19 (10), | Show Abstract | Read more

We investigated whether dried cerebrospinal fluid (CSF) conserved on filter paper can be used as a substrate for accurate PCR diagnosis of important causes of bacterial meningitis in the Lao PDR. Using mock CSF, we investigated and optimized filter paper varieties, paper punch sizes, elution volumes and quantities of DNA template to achieve sensitive and reliable detection of bacterial DNA from filter paper specimens. FTA Elute Micro Card™ (Whatman, Maidstone, UK) was the most sensitive, consistent and practical variety of filter paper. Following optimization, the lower limit of detection for Streptococcus pneumoniae from dried mock CSF spots was 14 genomic equivalents (GE)/μL (interquartile range 5.5 GE/μL) or 230 (IQR 65) colony forming units/mL. A prospective clinical evaluation for S. pneumoniae, S. suis and Neisseria meningitidis was performed. Culture and PCR performed on fresh liquid CSF from patients admitted with a clinical diagnosis of meningitis (n = 73) were compared with results derived from dried CSF spots. Four of five fresh PCR-positive CSF samples also tested PCR positive from dried CSF spots, with one patient under the limit of detection. In a retrospective study of S. pneumoniae samples (n = 20), the median (IQR; range) CSF S. pneumoniae bacterial load was 1.1 × 10 4 GE/μL (1.2 × 10 5 ; 1 to 6.1 × 10 6 DNA GE/μL). Utilizing the optimized methodology, we estimate an extrapolated sensitivity of 90%, based on the range of CSF genome counts found in Laos. Dried CSF filter paper spots could potentially help us to better understand the epidemiology of bacterial meningitis in resource-poor settings and guide empirical treatments and vaccination policies. © 2013 The Authors. Clinical Microbiology and Infection published by John Wiley & Sons Ltd on behalf of the European Society of Clinical Microbiology and Infectious Disease.

Wootton CI, Elliott IAM, Sengdetkha D, Vongsouvath M, Phongmany S, Dance DAB. 2013. Melioidosis: An unusual cause of recurrent buttock abscesses Clinical and Experimental Dermatology, 38 (4), pp. 427-428. | Read more

Rattanavong S, Vongthongchit S, Bounphamala K, Vongphakdy P, Gubler J, Mayxay M, Phetsouvanh R, Elliott I, Logan J, Hill R et al. 2012. Actinomycetoma in SE Asia: the first case from Laos and a review of the literature. BMC Infect Dis, 12 (1), pp. 349. | Show Abstract | Read more

BACKGROUND: Mycetoma is a chronic, localized, slowly progressing infection of the cutaneous and subcutaneous tissues caused either by fungi (eumycetoma or implantation mycosis) or by aerobic actinomycetes (actinomycetoma). It is acquired by traumatic implantation, most commonly in the tropics and subtropics, especially in rural agricultural communities. Although well recognized elsewhere in Asia, it has not been reported from the Lao People's Democratic Republic (Laos). CASE PRESENTATION: A 30 year-old female elementary school teacher and rice farmer from northeast Laos was admitted to Mahosot Hospital, Vientiane, with a massive growth on her left foot, without a history of trauma. The swelling had progressed slowly but painlessly over 5 years and multiple draining sinuses had developed. Ten days before admission the foot had increased considerably in size and became very painful, with multiple sinuses and discharge, preventing her from walking. Gram stain and bacterial culture of tissue biopsies revealed a branching filamentous Gram-positive bacterium that was subsequently identified as Actinomadura madurae by 16S rRNA gene amplification and sequencing. She was treated with long-term co-trimoxazole and multiple 3-week cycles of amikacin with a good therapeutic response. CONCLUSION: We report the first patient with actinomycetoma from Laos. The disease should be considered in the differential diagnosis of chronic skin and bone infections in patients from rural SE Asia.

Gilmore CP, Elliott I, Auer D, Maddison P. 2010. Diffuse cerebellar MR imaging changes in anti-Yo positive paraneoplastic cerebellar degeneration Journal of Neurology, 257 (3), pp. 490-491. | Read more

Ziglam HM, Elliott I, Wilson V, Hill K, Nathwani D. 2005. Clinical audit of linezolid use in a large teaching hospital Journal of Antimicrobial Chemotherapy, 56 (2), pp. 423-426. | Read more

Manivanh L, Pierret A, Rattanavong S, Kounnavongsa O, Buisson Y, Elliott I, Maeght J-L, Xayyathip K, Silisouk J, Vongsouvath M et al. 2017. Burkholderia pseudomallei in a lowland rice paddy: seasonal changes and influence of soil depth and physico-chemical properties. Sci Rep, 7 (1), pp. 3031. | Show Abstract | Read more

Melioidosis, a severe infection with the environmental bacterium Burkholderia pseudomallei, is being recognised increasingly frequently. What determines its uneven distribution within endemic areas is poorly understood. We cultured soil from a rice field in Laos for B. pseudomallei at different depths on 4 occasions over a 13-month period. We also measured physical and chemical parameters in order to identify associated characteristics. Overall, 195 of 653 samples (29.7%) yielded B. pseudomallei. A higher prevalence of B. pseudomallei was found at soil depths greater than the 30 cm currently recommended for B. pseudomallei environmental sampling. B. pseudomallei was associated with a high soil water content and low total nitrogen, carbon and organic matter content. Our results suggested that a sampling grid of 25 five metre square quadrats (i.e. 25 × 25 m) should be sufficient to detect B. pseudomallei at a given location if samples are taken at a soil depth of at least 60 cm. However, culture of B. pseudomallei in environmental samples is difficult and liable to variation. Future studies should both rely on molecular approaches and address the micro-heterogeneity of soil when investigating physico-chemical associations with the presence of B. pseudomallei.

Stoesser N, Xayaheuang S, Vongsouvath M, Phommasone K, Elliott I, Del Ojo Elias C, Crook DW, Newton PN, Buisson Y, Lee SJ, Dance DAB. 2015. Colonization with Enterobacteriaceae producing ESBLs in children attending pre-school childcare facilities in the Lao People's Democratic Republic. J Antimicrob Chemother, 70 (6), pp. 1893-1897. | Show Abstract | Read more

OBJECTIVES: Intestinal carriage constitutes an important reservoir of antimicrobial-resistant bacteria, with some of the highest rates reported from Asia. Antibiotic resistance has been little studied in Laos, where some antibiotics are available without restriction, but others such as carbapenems are not available. PATIENTS AND METHODS: We collected stools from 397 healthy children in 12 randomly selected pre-school childcare facilities in and around Vientiane. Colonization with ESBL-producing Enterobacteriaceae (ESBLE) and carbapenemase-producing Enterobacteriaceae (CPE) was detected using a disc diffusion screening test and ESBLE were characterized using WGS. Risk factor data were collected by questionnaire. RESULTS: Ninety-two children (23%) were colonized with ESBLE, mainly Escherichia coli carrying blaCTX-M and Klebsiella pneumoniae carrying blaSHV or blaCTX-M, which were frequently resistant to multiple antibiotic classes. Although residence in Vientiane Capital, foreign travel, higher maternal level of education, antibiotic use in the preceding 3 months and attending a childcare facility with a 'good' level of hygiene were all associated with ESBLE colonization on univariable analysis, a significant association remained only for antibiotic use when a stepwise approach was used with a multivariate random-effects model. WGS analysis suggested transmission in both childcare facilities and community settings. CONCLUSIONS: The high prevalence of paediatric colonization with ESBLE in Laos, one of the highest reported in Asia, is probably the result of inappropriate antibiotic use. Paediatric colonization with CPE was not identified in this study, but it is important to continue to monitor the spread of antibiotic-resistant Enterobacteriaceae in Laos.

Elliott I, Patel T, Shah J, Venkatesan P. 2014. West-African trypanosomiasis in a returned traveller from Ghana: an unusual cause of progressive neurological decline Case Reports, 2014 (aug14 1), pp. bcr2014204451-bcr2014204451. | Read more

Elliott I, Mayxay M, Yeuichaixong S, Lee SJ, Newton PN. 2014. The practice and clinical implications of tablet splitting in international health. Tropical medicine & international health : TM & IH, 19 (7), pp. 754-760. | Show Abstract | Read more

Tablet splitting is frequently performed to facilitate correct dosing, but the practice and implications in low-income settings have rarely been discussed. We selected eight drugs, with narrow therapeutic indices or critical dosages, frequently divided in the Lao PDR (Laos). These were split, by common techniques used in Laos, by four nurses and four laypersons. The mean percentage deviation from the theoretical expected weight and weight loss of divided tablets/capsules were recorded. Five of eight study drugs failed, on splitting, to meet European Pharmacopoeia recommendations for tablet weight deviation from the expected weight of tablet/capsule halves with 10% deviating by more than 25%. There was a significant difference in splitting accuracy between nurses and laypersons (P = 0.027). Coated and unscored tablets were less accurately split than uncoated (P = 0.03 and 0.0019 for each half) and scored (0.0001 for both halves) tablets. These findings have potential clinical implications on treatment outcome and the development of antimicrobial resistance. Investment by drug companies in a wider range of dosage units, particularly for narrow therapeutic index and critical dosage medicines, is strongly recommended. © 2014 The Authors. Tropical Medicine & International Health published by John Wiley & Sons Ltd.

Smit PW, Elliott I, Peeling RW, Mabey D, Newton PN. 2014. An overview of the clinical use of filter paper in the diagnosis of tropical diseases. Am J Trop Med Hyg, 90 (2), pp. 195-210. | Show Abstract | Read more

Tropical infectious diseases diagnosis and surveillance are often hampered by difficulties of sample collection and transportation. Filter paper potentially provides a useful medium to help overcome such problems. We reviewed the literature on the use of filter paper, focusing on the evaluation of nucleic acid and serological assays for diagnosis of infectious diseases using dried blood spots (DBS) compared with recognized gold standards. We reviewed 296 eligible studies and included 101 studies evaluating DBS and 192 studies on other aspects of filter paper use. We also discuss the use of filter paper with other body fluids and for tropical veterinary medicine. In general, DBS perform with sensitivities and specificities similar or only slightly inferior to gold standard sample types. However, important problems were revealed with the uncritical use of DBS, inappropriate statistical analysis, and lack of standardized methodology. DBS have great potential to empower healthcare workers by making laboratory-based diagnostic tests more readily accessible, but additional and more rigorous research is needed.

Elliott I, Dittrich S, Paris D, Sengduanphachanh A, Phoumin P, Newton PN. 2013. The use of dried cerebrospinal fluid filter paper spots as a substrate for PCR diagnosis of the aetiology of bacterial meningitis in the Lao PDR Clinical Microbiology and Infection, 19 (10), | Show Abstract | Read more

We investigated whether dried cerebrospinal fluid (CSF) conserved on filter paper can be used as a substrate for accurate PCR diagnosis of important causes of bacterial meningitis in the Lao PDR. Using mock CSF, we investigated and optimized filter paper varieties, paper punch sizes, elution volumes and quantities of DNA template to achieve sensitive and reliable detection of bacterial DNA from filter paper specimens. FTA Elute Micro Card™ (Whatman, Maidstone, UK) was the most sensitive, consistent and practical variety of filter paper. Following optimization, the lower limit of detection for Streptococcus pneumoniae from dried mock CSF spots was 14 genomic equivalents (GE)/μL (interquartile range 5.5 GE/μL) or 230 (IQR 65) colony forming units/mL. A prospective clinical evaluation for S. pneumoniae, S. suis and Neisseria meningitidis was performed. Culture and PCR performed on fresh liquid CSF from patients admitted with a clinical diagnosis of meningitis (n = 73) were compared with results derived from dried CSF spots. Four of five fresh PCR-positive CSF samples also tested PCR positive from dried CSF spots, with one patient under the limit of detection. In a retrospective study of S. pneumoniae samples (n = 20), the median (IQR; range) CSF S. pneumoniae bacterial load was 1.1 × 10 4 GE/μL (1.2 × 10 5 ; 1 to 6.1 × 10 6 DNA GE/μL). Utilizing the optimized methodology, we estimate an extrapolated sensitivity of 90%, based on the range of CSF genome counts found in Laos. Dried CSF filter paper spots could potentially help us to better understand the epidemiology of bacterial meningitis in resource-poor settings and guide empirical treatments and vaccination policies. © 2013 The Authors. Clinical Microbiology and Infection published by John Wiley & Sons Ltd on behalf of the European Society of Clinical Microbiology and Infectious Disease.

Wootton CI, Elliott IAM, Sengdetkha D, Vongsouvath M, Phongmany S, Dance DAB. 2013. Melioidosis: An unusual cause of recurrent buttock abscesses Clinical and Experimental Dermatology, 38 (4), pp. 427-428. | Read more

Rattanavong S, Vongthongchit S, Bounphamala K, Vongphakdy P, Gubler J, Mayxay M, Phetsouvanh R, Elliott I, Logan J, Hill R et al. 2012. Actinomycetoma in SE Asia: the first case from Laos and a review of the literature. BMC Infect Dis, 12 (1), pp. 349. | Show Abstract | Read more

BACKGROUND: Mycetoma is a chronic, localized, slowly progressing infection of the cutaneous and subcutaneous tissues caused either by fungi (eumycetoma or implantation mycosis) or by aerobic actinomycetes (actinomycetoma). It is acquired by traumatic implantation, most commonly in the tropics and subtropics, especially in rural agricultural communities. Although well recognized elsewhere in Asia, it has not been reported from the Lao People's Democratic Republic (Laos). CASE PRESENTATION: A 30 year-old female elementary school teacher and rice farmer from northeast Laos was admitted to Mahosot Hospital, Vientiane, with a massive growth on her left foot, without a history of trauma. The swelling had progressed slowly but painlessly over 5 years and multiple draining sinuses had developed. Ten days before admission the foot had increased considerably in size and became very painful, with multiple sinuses and discharge, preventing her from walking. Gram stain and bacterial culture of tissue biopsies revealed a branching filamentous Gram-positive bacterium that was subsequently identified as Actinomadura madurae by 16S rRNA gene amplification and sequencing. She was treated with long-term co-trimoxazole and multiple 3-week cycles of amikacin with a good therapeutic response. CONCLUSION: We report the first patient with actinomycetoma from Laos. The disease should be considered in the differential diagnosis of chronic skin and bone infections in patients from rural SE Asia.

Gilmore CP, Elliott I, Auer D, Maddison P. 2010. Diffuse cerebellar MR imaging changes in anti-Yo positive paraneoplastic cerebellar degeneration Journal of Neurology, 257 (3), pp. 490-491. | Read more

Ziglam HM, Elliott I, Wilson V, Hill K, Nathwani D. 2005. Clinical audit of linezolid use in a large teaching hospital Journal of Antimicrobial Chemotherapy, 56 (2), pp. 423-426. | Read more

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