Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU

Vientiane, Laos

Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU

Vientiane, Laos

Time filter

Source Type

Mayxay M.,Health Science University | Mayxay M.,Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU | Mayxay M.,University of Oxford | Cui W.,University of Melbourne | And 6 more authors.
BMC Public Health | Year: 2013

Background: Dengue remains an important cause of morbidity in Laos. Good knowledge, attitudes and practices (KAP) among the public regarding dengue prevention are required for the success of disease control. Very little is known about dengue KAP among the Lao general population. Methods. This was a KAP household survey on dengue conducted in a peri-urban Pak-Ngum district of Vientiane capital, Laos. A two-stage cluster sampling method was used to select a sample of participants to represent the general community. Participants from 231 households were surveyed using an interviewer-administered questionnaire. Results: Although 97% of the participants heard of dengue, there was a lack of depth of knowledge on dengue: 33% of them did not know that malaria and dengue were different diseases, 32% incorrectly believed that Aedes mosquito transmits malaria, 36% could not correctly report that Aedes mosquitoes bite most frequently at sunrise and sunset; and < 10% of them recognized that indoor water containers could be Aedes mosquito breeding sites. Attitude levels were moderately good with a high proportion (96%) of participants recognizing that dengue was a severe yet preventable disease. Self reported prevention methods were quite high yet observation of the participants' yards showed use of prevention methods to be only moderate. The majority (93%) of the interviewees did not believe that they had enough information on dengue. There was an association between good knowledge and better practices, but good knowledge was associated with worse attitudes. Conclusions: There is a lack of depth of knowledge regarding dengue in Pak-Ngum community and observation methods revealed that more needs to be done by community members themselves to prevent the spread of Aedes mosquitoes. © 2013 Mayxay et al.; licensee BioMed Central Ltd.


Tabernero P.,University of Oxford | Tabernero P.,Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU | Fernandez F.M.,Georgia Institute of Technology | Green M.,Centers for Disease Control and Prevention | And 4 more authors.
Malaria Journal | Year: 2014

Background: Poor quality medicines threaten the lives of millions of patients and are alarmingly common in many parts of the world. Nevertheless, the global extent of the problem remains unknown. Accurate estimates of the epidemiology of poor quality medicines are sparse and are influenced by sampling methodology and diverse chemical analysis techniques. In order to understand the existing data, the Antimalarial Quality Scientific Group at WWARN built a comprehensive, open-access, global database and linked Antimalarial Quality Surveyor, an online visualization tool. Analysis of the database is described here, the limitations of the studies and data reported, and their public health implications discussed. Methods. The database collates customized summaries of 251 published anti-malarial quality reports in English, French and Spanish by time and location since 1946. It also includes information on assays to determine quality, sampling and medicine regulation. Results: No publicly available reports for 60.6% (63) of the 104 malaria-endemic countries were found. Out of 9,348 anti-malarials sampled, 30.1% (2,813) failed chemical/packaging quality tests with 39.3% classified as falsified, 2.3% as substandard and 58.3% as poor quality without evidence available to categorize them as either substandard or falsified. Only 32.3% of the reports explicitly described their definitions of medicine quality and just 9.1% (855) of the samples collected in 4.6% (six) surveys were conducted using random sampling techniques. Packaging analysis was only described in 21.5% of publications and up to twenty wrong active ingredients were found in falsified anti-malarials. Conclusions: There are severe neglected problems with anti-malarial quality but there are important caveats to accurately estimate the prevalence and distribution of poor quality anti-malarials. The lack of reports in many malaria-endemic areas, inadequate sampling techniques and inadequate chemical analytical methods and instrumental procedures emphasizes the need to interpret medicine quality results with caution. The available evidence demonstrates the need for more investment to improve both sampling and analytical methodology and to achieve consensus in defining different types of poor quality medicines. © 2014 Tabernero et al.; licensee BioMed Central Ltd.


PubMed | Mahidol University, Naval Medical Research Center Asia and Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU
Type: | Journal: BMC infectious diseases | Year: 2016

C-Reactive Protein (CRP) has been shown to be an accurate biomarker for discriminating bacterial from viral infections in febrile patients in Southeast Asia. Here we investigate the accuracy of existing rapid qualitative and semi-quantitative tests as compared with a quantitative reference test to assess their potential for use in remote tropical settings.Blood samples were obtained from consecutive patients recruited to a prospective fever study at three sites in rural Laos. At each site, one of three rapid qualitative or semi-quantitative tests was performed, as well as a corresponding quantitative NycoCard Reader II as a reference test. We estimate the sensitivity and specificity of the three tests against a threshold of 10 mg/L and kappa values for the agreement of the two semi-quantitative tests with the results of the reference test.All three tests showed high sensitivity, specificity and kappa values as compared with the NycoCard Reader II. With a threshold of 10 mg/L the sensitivity of the tests ranged from 87-98 % and the specificity from 91-98 %. The weighted kappa values for the semi-quantitative tests were 0.7 and 0.8.The use of CRP rapid tests could offer an inexpensive and effective approach to improve the targeting of antibiotics in remote settings where health facilities are basic and laboratories are absent. This study demonstrates that accurate CRP rapid tests are commercially available; evaluations of their clinical impact and cost-effectiveness at point of care is warranted.


Dittrich S.,Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU | Dittrich S.,University of Oxford | Rattanavong S.,Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU | Lee S.J.,University of Oxford | And 19 more authors.
The Lancet Global Health | Year: 2015

Background: Scrub typhus (caused by Orientia tsutsugamushi), murine typhus (caused by Rickettsia typhi), and leptospirosis are common causes of febrile illness in Asia; meningitis and meningoencephalitis are severe complications. However, scarce data exist for the burden of these pathogens in patients with CNS disease in endemic countries. Laos is representative of vast economically poor rural areas in Asia with little medical information to guide public health policy. We assessed whether these pathogens are important causes of CNS infections in Laos. Methods: Between Jan 10, 2003, and Nov 25, 2011, we enrolled 1112 consecutive patients of all ages admitted with CNS symptoms or signs requiring a lumbar puncture at Mahosot Hospital, Vientiane, Laos. Microbiological examinations (culture, PCR, and serology) targeted so-called conventional bacterial infections (Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, S suis) and O tsutsugamushi, Rickettsia typhi/Rickettsia spp, and Leptospira spp infections in blood or cerebrospinal fluid (CSF). We analysed and compared causes and clinical and CSF characteristics between patient groups. Findings: 1051 (95%) of 1112 patients who presented had CSF available for analysis, of whom 254 (24%) had a CNS infection attributable to a bacterial or fungal pathogen. 90 (35%) of these 254 infections were caused by O tsutsugamushi, R typhi/Rickettsia spp, or Leptospira spp. These pathogens were significantly more frequent than conventional bacterial infections (90/1051 [9%] vs 42/1051 [4%]; p<0· 0001) by use of conservative diagnostic definitions. CNS infections had a high mortality (236/876 [27%]), with 18% (13/71) for R typhi/Rickettsia spp, O tsutsugamushi, and Leptospira spp combined, and 33% (13/39) for conventional bacterial infections (p=0· 076). Interpretation: Our data suggest that R typhi/Rickettsia spp, O tsutsugamushi, and Leptospira spp infections are important causes of CNS infections in Laos. Antibiotics, such as tetracyclines, needed for the treatment of murine typhus and scrub typhus, are not routinely advised for empirical treatment of CNS infections. These severely neglected infections represent a potentially large proportion of treatable CNS disease burden across vast endemic areas and need more attention. Funding: Wellcome Trust UK. © 2015 Dittrich et al. Open Access article published under the terms of CC BY.


PubMed | Salavan Provincial Hospital, Aix - Marseille University, Mahidol University and Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU
Type: Journal Article | Journal: PLoS neglected tropical diseases | Year: 2016

Dengue virus infection causes major public health problems in tropical and subtropical areas. In many endemic areas, including the Lao PDR, inadequate access to laboratory facilities is a major obstacle to surveillance and study of dengue epidemiology. Filter paper is widely used for blood collection for subsequent laboratory testing for antibody and nucleic acid detection. For the first time, we demonstrate that dengue viral RNA can be extracted from dengue rapid diagnostic tests (RDT) and then submitted to real-time RT-PCR for serotyping.We evaluated the Standard Diagnostics (SD) Bioline Dengue Duo RDT, a commonly used test in dengue endemic areas. First, using the QIAamp RNA kit, dengue RNA was purified from the sample pad of the NS1 RDT loaded with virus isolates of the four serotypes, then quantified by RT-PCR. We observed greater recovery of virus, with a mean of 27 times more RNA recovered from RDT, than from filter paper. Second, we evaluated dengue NS1 RDTs from patients at Mahosot Hospital, Vientiane, (99 patients) and from rural Salavan Provincial Hospital (362 patients). There was good agreement between dengue RT-PCR from NS1 RDT with RT-PCR performed on RNA extracted from patient sera, either using RDT loaded with blood (82.8% and 91.4%, in Vientiane and Salavan, respectively) or serum (91.9% and 93.9%). There was 100% concordance between RDT and serum RT-PCR of infecting dengue serotype.Therefore, the collection of NS1 positive RDTs, which do not require cold storage, may be a novel approach for dengue serotyping by RT-PCR and offers promising prospects for the collection of epidemiological data from previously inaccessible tropical areas to aid surveillance and public health interventions.


Dance D.,Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU | Dance D.,University of Oxford
International Journal of Antimicrobial Agents | Year: 2014

Melioidosis, infection with Burkholderia pseudomallei, is being recognised with increasing frequency and is probably more common than currently appreciated. Treatment recommendations are based on a series of clinical trials conducted in Thailand over the past 25 years. Treatment is usually divided into two phases: in the first, or acute phase, parenteral drugs are given for =10 days with the aim of preventing death from overwhelming sepsis; in the second, or eradication phase, oral drugs are given, usually to complete a total of 20 weeks, with the aim of preventing relapse. Specific treatment for individual patients needs to be tailored according to clinical manifestations and response, and there remain many unanswered questions. Some patients with very mild infections can probably be cured by oral agents alone. Ceftazidime is the mainstay of acute-phase treatment, with carbapenems reserved for severe infections or treatment failures and amoxicillin/clavulanic acid (co-amoxiclav) as second-line therapy. Trimethoprim/sulfamethoxazole (co-trimoxazole) is preferred for the eradication phase, with the alternative of co-amoxiclav. In addition, the best available supportive care is needed, along with drainage of abscesses whenever possible. Treatment for melioidosis is unaffordable for many in endemic areas of the developing world, but the relative costs have reduced over the past decade. Unfortunately there is no likelihood of any new or cheaper options becoming available in the immediate future. Recommendations for prophylaxis following exposure to B. pseudomallei have been made, but the evidence suggests that they would probably only delay rather than prevent the development of infection. © 2014 The Author.


Taylor A.J.,Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU | Taylor A.J.,University of Oxford | Paris D.H.,Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU | Paris D.H.,University of Oxford | And 3 more authors.
PLoS Neglected Tropical Diseases | Year: 2015

Background Scrub typhus, a bacterial infection caused by Orientia tsutsugamushi, is increasingly recognized as an important cause of fever in Asia, with an estimated one million infections occurring each year. Limited access to health care and the disease’s non-specific symptoms mean that many patients are undiagnosed and untreated, but the mortality from untreated scrub typhus is unknown. This review systematically summarizes the literature on the untreated mortality from scrub typhus and disease outcomes. Methodology/Principal Findings A literature search was performed to identify patient series containing untreated patients. Patients were included if they were symptomatic and had a clinical or laboratory diagnosis of scrub typhus and excluded if they were treated with antibiotics. The primary outcome was mortality from untreated scrub typhus and secondary outcomes were total days of fever, clinical symptoms, and laboratory results. A total of 76 studies containing 89 patient series and 19,644 patients were included in the final analysis. The median mortality of all patient series was 6.0% with a wide range (min-max) of 0–70%. Many studies used clinical diagnosis alone and had incomplete data on secondary outcomes. Mortality varied by location and increased with age and in patients with myocarditis, delirium, pneumonitis, or signs of hemorrhage, but not according to sex or the presence of an eschar or meningitis. Duration of fever was shown to be long (median 14.4 days Range (9–19)). Conclusions Results show that the untreated mortality from scrub typhus appears lower than previously reported estimates. More data are required to clarify mortality according to location and host factors, clinical syndromes including myocarditis and central nervous system disease, and in vulnerable mother-child populations. Increased surveillance and improved access to diagnostic tests are required to accurately estimate the untreated mortality of scrub typhus. This information would facilitate reliable quantification of DALYs and guide empirical treatment strategies. © 2015 Taylor et al.


Taylor A.J.,Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU | Taylor A.J.,University of Oxford | Paris D.H.,Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU | Paris D.H.,University of Oxford | And 3 more authors.
PLoS Neglected Tropical Diseases | Year: 2015

Background Leptospirosis occurs worldwide, but the global incidence of human disease and its mortality are not well understood. Many patients are undiagnosed and untreated due to its nonspecific symptoms and a lack of access to diagnostics. This study systematically reviews the literature to clarify the mortality from untreated leptospirosis. Results will help quantify the global burden of disease and guide health policies. Methodology/Principal Findings A comprehensive literature search was performed to identify untreated patient series. Included patients were symptomatic, but asymptomatic patients and those who had received antibiotics, dialysis or who were treated on Intensive Care Units were excluded. Included patients had a confirmed laboratory diagnosis by culture, PCR, or serological tests. Data was extracted and individual patient series were assessed for bias. Thirty-five studies, comprising 41 patient series and 3,390 patients, were included in the study. A high degree of bias within studies was shown due to limitations in study design, diagnostic tests and missing data. Median series mortality was 2.2% (Range 0.0 – 39.7%), but mortality was high in jaundiced patients (19.1%) (Range 0.0 – 39.7%), those with renal failure 12.1% (Range 0-25.0%) and in patients aged over 60 (60%) (Range 33.3-60%), but low in anicteric patients (0%) (Range 0-1.7%). Conclusions This systematic review contributes to our understanding of the mortality of untreated leptospirosis and provides data for the estimation of DALYs attributable to this disease.We show that mortality is significantly higher in older patients with icteric disease or renal failure but is lower in younger, anicteric patients. Increased surveillance and accurate point-of-care diagnostics are required to better understand the incidence and improve diagnosis of disease. Empirical treatment strategies should prioritize early treatment to improve outcomes from leptospirosis. © 2015 Taylor et al.


Elliott I.,Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU | Elliott I.,University of Oxford | Dittrich S.,Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU | Dittrich S.,University of Oxford | And 6 more authors.
Clinical Microbiology and Infection | Year: 2013

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 × 104 GE/μL (1.2 × 105; 1 to 6.1 × 106 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.


Dittrich S.,Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU | Dittrich S.,University of Oxford | Castonguay-Vanier J.,Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU | Castonguay-Vanier J.,University of Oxford | And 8 more authors.
Journal of Clinical Microbiology | Year: 2014

Murine typhus is a flea-borne disease of worldwide distribution caused by Rickettsia typhi. Although treatment with tetracycline antibiotics is effective, treatment is often misguided or delayed due to diagnostic difficulties. As the gold standard immunofluorescence assay is imperfect, we aimed to develop and evaluate a loop-mediated isothermal amplification (LAMP) assay. LAMP assays have the potential to fulfill the WHO ASSURED criteria (affordable, sensitive, specific, user friendly, robust and rapid, equipment free, deliverable to those who need them) for diagnostic methodologies, as they can detect pathogen-derived nucleic acid with low technical expenditure. The LAMP assay was developed using samples of bacterial isolates (n=41), buffy coat specimens from R. typhi PCR-positive Lao patients (n=42), and diverse negative controls (n=47). The method was then evaluated prospectively using consecutive patients with suspected scrub typhus or murine typhus (n=266). The limit of detection was ∼40 DNA copies/LAMP reaction, with an analytical sensitivity of<10 DNA copies/reaction based on isolate dilutions. Despite these low cutoffs, the clinical sensitivity was disappointing, with 48% (95% confidence interval [95% CI], 32.5 to 62.7%) (specificity, 100% [95% CI, 100 to 100%]) in the developmental phase and 33% (95% CI, 9.2 to 56.8%) (specificity, 98.5% [95% CI, 97.0% to 100%]) in the prospective study. This low diagnostic accuracy was attributed to low patient R. typhi bacterial loads (median, 210 DNA copies/ml blood; interquartile range, 130 to 500). PCR-positive but LAMP-negative samples demonstrated significantly lower bacterial loads than LAMP-positive samples. Our findings highlight the diagnostic challenges for diseases with low pathogen burdens and emphasize the need to integrate pathogen biology with improved template production for assay development strategies. Copyright © 2014 Dittrich et al.

Loading Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU collaborators
Loading Lao Oxford Mahosot Hospital Wellcome Trust Research Unit LOMWRU collaborators