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1.
Wellcome Open Res ; 9: 421, 2024.
Article in English | MEDLINE | ID: mdl-39246519

ABSTRACT

Background: Burkholderia thailandensis is an environmental bacteria closely related to Burkholderia pseudomallei that rarely causes infection in humans. Some environmental isolates have shown to express a capsular polysaccharide known as B. thailandensis capsular variant (BTCV), but human infection has not previously been reported. Although B. thailandednisis has been identified in environmental samples in Laos before, there have not been any human cases reported. Case: A 44-year-old man presented to a district hospital in Laos with a short history of fever and pain in his left foot. Physical examination identified a deep soft-tissue abscess in his left foot and an elevated white blood count. A deep pus sample was taken and melioidosis was suspected from preliminary laboratory tests. The patient was initially started on cloxacillin, ceftriaxone and metronidazole, and was then changed to ceftazidime treatment following local melioidosis treatment guidelines. Laboratory methods: A deep pus sample was sent to Mahosot Hospital microbiology laboratory where a mixed infection was identified including Burkholderia sp. Conventional identification tests and API 20NE were inconclusive, and the B. pseudomallei-specific latex agglutination was positive. The isolate then underwent a Burkholderia species specific PCR which identified the isolate as B. thailandensis. The isolate was sent for sequencing on the Illumina NovaSeq 6000 system and multi-locus sequence typing analysis identified the isolate had the same sequence type (ST696) as B. thailandensis E555, a strain which expresses a B. pseudomallei-like capsular polysaccharide. Conclusion: This is the first report of human infection with B. thailandensis in Laos, and the first report of any human infection with the B. thailandensis capsular variant. Due to the potential for laboratory tests to incorrectly identify this bacteria, staff in endemic areas for B. thailandensis and B. pseudomallei should be aware and ensure that appropriate confirmatory methods are used to differentiate between the species.


> Burkholderia thailandensis is a bacteria that is found in the environment. Rarely, this bacteria can cause infection in humans. Here we report a B. thailandensis infection in a 44 year old male in Laos. The patient sustained a puncture wound in his left foot and when presenting at a district hospital was prescribed cloxacillin. The wound did not improve and on day three of admission, a pus sample was sent to Mahosot Hospital Microbiology Laboratory for investigation. A preliminary diagnosis of melioidosis, caused by the bacteria Burkholderia pseudomallei, was made and antibiotic treatment was changed. Additional laboratory investigation determined that the isolate was actually B. thailandensis and antibiotic treatment was further changed. Due to the inconclusive results of the initial laboratory tests, the isolate was sent for sequencing and was identified as a strain which expresses a B. pseudomallei-like capsular polysaccharide. This is the first report of infection with B. thailandensis in Laos and the first report of infection with a B. thailandensis capsular variant.

2.
Am J Trop Med Hyg ; 2024 Sep 03.
Article in English | MEDLINE | ID: mdl-39226893

ABSTRACT

Melioidosis is an emerging tropical infectious disease with a rising global burden caused by the environmental bacterium Burkholderia pseudomallei. It is endemic in Southeast and South Asia, including Bangladesh. A rare aminoglycoside-susceptible B. pseudomallei isolate (Y2019) has recently been reported from a melioidosis patient in Dhaka, Bangladesh. To understand the geographical origins of Y2019, we subjected it and 10 other isolates from Bangladesh to whole-genome sequencing. In a phylogenetic tree with a global set of B. pseudomallei genomes, most Bangladeshi genomes clustered tightly within the Asian clade. In contrast, Y2019 was closely related to ST881 isolates from Sarawak, Malaysian Borneo, a gentamicin-sensitive sequence type, suggesting infection in Borneo. Y2019 also contained the same gentamicin sensitivity conferring nonsynonymous mutation in the drug efflux pump encoding the amrB gene. In the absence of a full travel history, whole-genome sequencing and bioinformatics tools have revealed the likely origin of this rare isolate.

3.
Drug Resist Updat ; 76: 101121, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39018660

ABSTRACT

In a clinical isolate of Burkholderia pseudomallei from Hainan, the association between the emergence of ceftazidime resistance and a novel PenA P174L allele was identified for the first time, providing an understanding of one mechanism by which ceftazidime resistance arises in B. pseudomallei.


Subject(s)
Anti-Bacterial Agents , Burkholderia pseudomallei , Ceftazidime , Drug Resistance, Bacterial , Melioidosis , Microbial Sensitivity Tests , Point Mutation , Burkholderia pseudomallei/genetics , Burkholderia pseudomallei/drug effects , Ceftazidime/pharmacology , Humans , China , Anti-Bacterial Agents/pharmacology , Melioidosis/microbiology , Melioidosis/drug therapy , Drug Resistance, Bacterial/genetics , Bacterial Proteins/genetics , Alleles
4.
Emerg Infect Dis ; 30(4): 791-794, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38526300

ABSTRACT

In September 2021, a total of 25 patients diagnosed with COVID-19 developed acute melioidosis after (median 7 days) admission to a COVID-19 field hospital in Thailand. Eight nonpotable tap water samples and 6 soil samples were culture-positive for Burkholderia pseudomallei. Genomic analysis suggested contaminated tap water as the likely cause of illness.


Subject(s)
Burkholderia pseudomallei , COVID-19 , Melioidosis , Humans , Melioidosis/epidemiology , Thailand/epidemiology , Burkholderia pseudomallei/genetics , Water
5.
Microbiol Spectr ; 12(3): e0332123, 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38299821

ABSTRACT

Burkholderia pseudomallei and Burkholderia cepacia are Gram-negative, soil-dwelling bacteria that are found in a wide variety of environmental niches. While B. pseudomallei is the causative agent of melioidosis in humans and animals, members of the B. cepacia complex typically only cause disease in immunocompromised hosts. In this study, we report the identification of B. cepacia strains isolated from either patients or soil in Laos and Thailand that express a B. pseudomallei-like 6-deoxyheptan capsular polysaccharide (CPS). These B. cepacia strains were initially identified based on their positive reactivity in a latex agglutination assay that uses the CPS-specific monoclonal antibody (mAb) 4B11. Mass spectrometry and recA sequencing confirmed the identity of these isolates as B. cepacia (formerly genomovar I). Total carbohydrates extracted from B. cepacia cell pellets reacted with B. pseudomallei CPS-specific mAbs MCA147, 3C5, and 4C4, but did not react with the B. pseudomallei lipopolysaccharide-specific mAb Pp-PS-W. Whole genome sequencing of the B. cepacia isolates revealed the presence of genes demonstrating significant homology to those comprising the B. pseudomallei CPS biosynthetic gene cluster. Collectively, our results provide compelling evidence that B. cepacia strains expressing the same CPS as B. pseudomallei co-exist in the environment alongside B. pseudomallei. Since CPS is a target that is often used for presumptive identification of B. pseudomallei, it is possible that the occurrence of these unique B. cepacia strains may complicate the diagnosis of melioidosis.IMPORTANCEBurkholderia pseudomallei, the etiologic agent of melioidosis, is an important cause of morbidity and mortality in tropical and subtropical regions worldwide. The 6-deoxyheptan capsular polysaccharide (CPS) expressed by this bacterial pathogen is a promising target antigen that is useful for rapidly diagnosing melioidosis. Using assays incorporating CPS-specific monoclonal antibodies, we identified both clinical and environmental isolates of Burkholderia cepacia that express the same CPS antigen as B. pseudomallei. Because of this, it is important that staff working in melioidosis-endemic areas are aware that these strains co-exist in the same niches as B. pseudomallei and do not solely rely on CPS-based assays such as latex-agglutination, AMD Plus Rapid Tests, or immunofluorescence tests for the definitive identification of B. pseudomallei isolates.


Subject(s)
Burkholderia cepacia , Burkholderia pseudomallei , Melioidosis , Animals , Humans , Burkholderia pseudomallei/genetics , Melioidosis/diagnosis , Melioidosis/microbiology , Burkholderia cepacia/genetics , Polysaccharides , Antibodies, Monoclonal , Soil
6.
Emerg Infect Dis ; 30(3): 599-600, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38407187

ABSTRACT

In 2019, a melioidosis case in Maryland, USA, was shown to have been acquired from an ornamental fish tank contaminated with Burkholderia pseudomallei bacteria, likely derived from Southeast Asia. We investigated the presence of B. pseudomallei in ornamental fish tanks in the endemic area of Vientiane, Laos.


Subject(s)
Burkholderia pseudomallei , Melioidosis , Animals , Laos/epidemiology , Burkholderia pseudomallei/genetics , Melioidosis/epidemiology , Melioidosis/veterinary , Bacteria , Fishes
7.
Med Phys ; 51(2): 712-739, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38018710

ABSTRACT

Currently, there are multiple breast dosimetry estimation methods for mammography and its variants in use throughout the world. This fact alone introduces uncertainty, since it is often impossible to distinguish which model is internally used by a specific imaging system. In addition, all current models are hampered by various limitations, in terms of overly simplified models of the breast and its composition, as well as simplistic models of the imaging system. Many of these simplifications were necessary, for the most part, due to the need to limit the computational cost of obtaining the required dose conversion coefficients decades ago, when these models were first implemented. With the advancements in computational power, and to address most of the known limitations of previous breast dosimetry methods, a new breast dosimetry method, based on new breast models, has been developed, implemented, and tested. This model, developed jointly by the American Association of Physicists in Medicine and the European Federation for Organizations of Medical Physics, is applicable to standard mammography, digital breast tomosynthesis, and their contrast-enhanced variants. In addition, it includes models of the breast in both the cranio-caudal and the medio-lateral oblique views. Special emphasis was placed on the breast and system models used being based on evidence, either by analysis of large sets of patient data or by performing measurements on imaging devices from a range of manufacturers. Due to the vast number of dose conversion coefficients resulting from the developed model, and the relative complexity of the calculations needed to apply it, a software program has been made available for download or online use, free of charge, to apply the developed breast dosimetry method. The program is available for download or it can be used directly online. A separate User's Guide is provided with the software.


Subject(s)
Breast Neoplasms , Breast , Humans , Female , Breast/diagnostic imaging , Mammography/methods , Radiometry/methods , Monte Carlo Method , Breast Neoplasms/diagnostic imaging
8.
Microb Genom ; 9(5)2023 05.
Article in English | MEDLINE | ID: mdl-37171860

ABSTRACT

Increased colonization by antimicrobial-resistant organisms is closely associated with international travel. This study investigated the diversity of mobile genetic elements involved with antimicrobial resistance (AMR) gene carriage in extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli that colonized travellers to Laos. Long-read sequencing was used to reconstruct complete plasmid sequences from 48 isolates obtained from the daily stool samples of 23 travellers over a 3 week period. This method revealed a collection of 105 distinct plasmids, 38.1 % (n=40) of which carried AMR genes. The plasmids in this population were diverse, mostly unreported and included 38 replicon types, with F-type plasmids (n=23) the most prevalent amongst those carrying AMR genes. Fine-scale analysis of all plasmids identified numerous AMR gene contexts and emphasized the importance of IS elements, specifically members of the IS6/IS26 family, in the evolution of complex multidrug resistance regions. We found a concerning convergence of ESBL and colistin resistance determinants, with three plasmids from two different F-type lineages carrying bla CTX-M and mcr genes. The extensive diversity seen here highlights the worrying probability that stable new vehicles for AMR will evolve in E. coli populations that can disseminate internationally through travel networks.


Subject(s)
Escherichia coli Infections , Escherichia coli , Humans , Anti-Bacterial Agents/pharmacology , Escherichia coli Infections/epidemiology , Laos , beta-Lactamases/genetics , Drug Resistance, Bacterial/genetics , Plasmids/genetics
9.
Wellcome Open Res ; 7: 148, 2022.
Article in English | MEDLINE | ID: mdl-36324702

ABSTRACT

Background: Streptococcus agalactiae is a normal commensal of the human gastro-intestinal and female genital tracts. It causes serious disease in neonates and pregnant women, as well as non-pregnant adults. Food-borne outbreaks have also been described. A link between invasive Group B streptococcus (GBS) infection in humans caused by S. agalactiae serotype III-4, sequence type 283 (ST283) and the consumption of raw fresh-water fish was first described in Singapore in 2015. Case presentation: We report the simultaneous occurrence of acute fever and myalgia in two sisters who were visiting Laos. Both were found to have invasive GBS ST283 infection, confirmed by blood culture. Infection was temporally linked to fish consumption. They responded well to intravenous antibiotics within 48 hours. Conclusions: Food-borne transmission of Streptococcus agalactiae is an important and under-recognised source of serious human disease throughout Southeast Asia and possibly beyond.

10.
Infect Dis Poverty ; 11(1): 87, 2022 Aug 04.
Article in English | MEDLINE | ID: mdl-35927751

ABSTRACT

BACKGROUND: Burkholderia pseudomallei is a tropical pathogen that causes melioidosis. Its intrinsic drug-resistance is a leading cause of treatment failure, and the few available antibiotics require prolonged use to be effective. This study aimed to assess the clinical potential of B. pseudomallei phages isolated from Hainan, China. METHODS: Burkholderia pseudomallei strain (HNBP001) was used as the isolation host, and phages were recovered from domestic environmental sources, which were submitted to the host range determination, lytic property assays, and stability tests. The best candidate was examined via the transmission electron microscope for classification. With its genome sequenced and analyzed, its protective efficacy against B. pseudomallei infection in A549 cells and Caenorhabditis elegans was evaluated, in which cell viability and survival rates were compared using the one-way ANOVA method and the log-rank test. RESULTS: A phage able to lyse 24/25 clinical isolates was recovered. It was classified in the Podoviridae family and was found to be amenable to propagation. Under the optimal multiplicity of infection (MOI) of 0.1, an eclipse period of around 20 min and a high titer (1012 PFU/ml) produced within 1 h were demonstrated. This phage was found stabile at a wide range of temperatures (24, 37, 40, 50, and 60 °C) and pH values (3-12). After being designated as vB_BpP_HN01, it was fully sequenced, and the 71,398 bp linear genome, containing 93 open reading frames and a tRNA-Asn, displayed a low sequence similarity with known viruses. Additionally, protective effects of applications of vB_BpP_HN01 (MOI = 0.1 and MOI = 1) alone or in combination with antibiotics were found to improve viability of infected cells (70.6 ± 6.8%, 85.8 ± 5.7%, 91.9 ± 1.8%, and 96.8 ± 1.8%, respectively). A significantly reduced mortality (10%) and a decreased pathogen load were demonstrated in infected C. elegans following the addition of this phage. CONCLUSIONS: As the first B. pseudomallei phage was isolated in Hainan, China, phage vB_BpP_HN01 was characterized by promising lytic property, stability, and efficiency of bacterial elimination during the in vitro/vivo experiments. Therefore, we can conclude that it is a potential alternative agent for combating melioidosis.


Subject(s)
Bacteriophages , Burkholderia pseudomallei , Melioidosis , Phage Therapy , Animals , Anti-Bacterial Agents , Bacteriophages/genetics , Caenorhabditis elegans , Melioidosis/microbiology , Melioidosis/therapy , Phage Therapy/methods
11.
Microbiol Spectr ; 10(4): e0076522, 2022 08 31.
Article in English | MEDLINE | ID: mdl-35924843

ABSTRACT

Burkholderia pseudomallei is the causative agent of melioidosis, a life-threatening disease common in Southeast Asia and northern Australia. Melioidosis often presents with nonspecific symptoms and has a fatality rate of upwards of 70% when left untreated. The gold standard for diagnosis is culturing B. pseudomallei from patient samples. Bacterial culture, however, can take up to 7 days, and its sensitivity is poor, at roughly 60%. The successful administration of appropriate antibiotics is reliant on rapid and accurate diagnosis. Hence, there is a genuine need for new diagnostics for this deadly pathogen. The Active Melioidosis Detect (AMD) lateral flow immunoassay (LFI) detects the capsular polysaccharide (CPS) of B. pseudomallei. The assay is designed for use on various clinical samples, including serum and urine; however, there are limited data to support which clinical matrices are the best candidates for detecting CPS. In this study, concentrations of CPS in paired serum and urine samples from melioidosis patients were determined using a quantitative antigen capture enzyme-linked immunosorbent assay. In parallel, samples were tested with the AMD LFI, and the results of the two immunoassays were compared. Additionally, centrifugal concentration was performed on a subset of urine samples to determine if this method may improve detection when CPS levels are initially low or undetectable. The results indicate that while CPS levels varied within the two matrices, there tended to be higher concentrations in urine. The AMD LFI detected CPS in 40.5% of urine samples, compared to 6.5% of serum samples, suggesting that urine is a preferable matrix for point-of-care diagnostic assays. IMPORTANCE Melioidosis is very challenging to diagnose. There is a clear need for a point-of-care assay for the detection of B. pseudomallei antigen directly from patient samples. The Active Melioidosis Detect lateral flow immunoassay detects the capsular polysaccharide (CPS) of B. pseudomallei and is designed for use on various clinical samples, including serum and urine. However, there are limited data regarding which clinical matrix is preferable for the detection of CPS. This study addresses this question by examining quantitative CPS levels in paired serum and urine samples and relating them to clinical parameters. Additionally, centrifugal concentration was performed on a subset of urine samples to determine whether this might enable the detection of CPS in samples in which it was initially present at low or undetectable levels. These results provide valuable insights into the detection of CPS in patients with melioidosis and suggest potential ways forward in the diagnosis and treatment of this challenging disease.


Subject(s)
Burkholderia pseudomallei , Melioidosis , Humans , Immunoassay/methods , Melioidosis/diagnosis , Melioidosis/microbiology , Polysaccharides , Sensitivity and Specificity
12.
J Med Imaging (Bellingham) ; 9(3): 033504, 2022 May.
Article in English | MEDLINE | ID: mdl-35692280

ABSTRACT

Purpose: We set out a fully developed algorithm for adapting mammography images to appear as if acquired using different technique factors by changing the signal and noise within the images. The algorithm accounts for difference between the absorption by the object being imaged and the imaging system. Approach: Images were acquired using a Hologic Selenia Dimensions x-ray unit for the validation, of three thicknesses of polymethyl methacrylate (PMMA) blocks with or without different thicknesses of PMMA contrast objects acquired for a range of technique factors. One set of images was then adapted to appear the same as a target image acquired with a higher or lower tube voltage and/or a different anode/filter combination. The average linearized pixel value, normalized noise power spectra (NNPS), and standard deviation of the flat field images and the contrast-to-noise ratio (CNR) of the contrast object images were calculated for the simulated and target images. A simulation study tested the algorithm on images created using a voxel breast phantom at different technique factors and the images compared using local signal level, variance, and power spectra. Results: The average pixel value, NNPS, and standard deviation for the simulated and target images were found to be within 9%. The CNRs of the simulated and target images were found to be within 5% of each other. The differences between the target and simulated images of the voxel phantom were similar to those of the natural variability. Conclusions: We demonstrated that images can be successfully adapted to appear as if acquired using different technique factors. Using this conversion algorithm, it may be possible to examine the effect of tube voltage and anode/filter combination on cancer detection using clinical images.

13.
Sci Rep ; 12(1): 8674, 2022 05 23.
Article in English | MEDLINE | ID: mdl-35606475

ABSTRACT

The environmental distribution of Burkholderia pseudomallei, the causative agent of melioidosis, remains poorly understood. B. pseudomallei is known to have the ability to occupy a variety of environmental niches, particularly in soil. This paper provides novel information about a putative association of soil biogeochemical heterogeneity and the vertical distribution of B. pseudomallei. We investigated (1) the distribution of B. pseudomallei along a 300-cm deep soil profile together with the variation of a range of soil physico-chemical properties; (2) whether correlations between the distribution of B. pseudomallei and soil physico-chemical properties exist and (3) when they exist, what such correlations indicate with regards to the environmental conditions conducive to the occurrence of B. pseudomallei in soils. Unexpectedly, the highest concentrations of B. pseudomallei were observed between 100 and 200 cm below the soil surface. Our results indicate that unravelling the environmental conditions favorable to B. pseudomallei entails considering many aspects of the actual complexity of soil. Important recommendations regarding environmental sampling for B. pseudomallei can be drawn from this work, in particular that collecting samples down to the water table is of foremost importance, as groundwater persistence appears to be a controlling factor of the occurrence of B. pseudomallei in soil.


Subject(s)
Burkholderia pseudomallei , Melioidosis , Humans , Melioidosis/epidemiology , Soil , Soil Microbiology , Specimen Handling
14.
Med Phys ; 49(8): 5423-5438, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35635844

ABSTRACT

BACKGROUND: Understanding the magnitude and variability of the radiation dose absorbed by the breast fibroglandular tissue during mammography and digital breast tomosynthesis (DBT) is of paramount importance to assess risks versus benefits. Although homogeneous breast models have been proposed and used for decades for this purpose, they do not accurately reflect the actual heterogeneous distribution of the fibroglandular tissue in the breast, leading to biases in the estimation of dose from these modalities. PURPOSE: To develop and validate a method to generate patient-derived, heterogeneous digital breast phantoms for breast dosimetry in mammography and DBT. METHODS: The proposed phantoms were developed starting from patient-based models of compressed breasts, generated for multiple thicknesses and representing the two standard views acquired in mammography and DBT, that is, cranio-caudal (CC) and medio-lateral-oblique (MLO). Internally, the breast phantoms were defined as consisting of an adipose/fibroglandular tissue mixture, with a nonspatially uniform relative concentration. The parenchyma distributions were obtained from a previously described model based on patient breast computed tomography data that underwent simulated compression. Following these distributions, phantoms with any glandular fraction (1%-100%) and breast thickness (12-125 mm) can be generated, for both views. The phantoms were validated, in terms of their accuracy for average normalized glandular dose (Dg N) estimation across samples of patient breasts, using 88 patient-specific phantoms involving actual patient distribution of the fibroglandular tissue in the breast, and compared to that obtained using a homogeneous model similar to those currently used for breast dosimetry. RESULTS: The average Dg N estimated for the proposed phantoms was concordant with that absorbed by the patient-specific phantoms to within 5% (CC) and 4% (MLO). These Dg N estimates were over 30% lower than those estimated with the homogeneous models, which overestimated the average Dg N by 43% (CC), and 32% (MLO) compared to the patient-specific phantoms. CONCLUSIONS: The developed phantoms can be used for dosimetry simulations to improve the accuracy of dose estimates in mammography and DBT.


Subject(s)
Breast Neoplasms , Mammography , Breast/diagnostic imaging , Breast Neoplasms/diagnostic imaging , Female , Humans , Mammography/methods , Phantoms, Imaging , Radiometry/methods , Tomography, X-Ray Computed/methods
15.
J Infect Dis ; 225(7): 1266-1273, 2022 04 01.
Article in English | MEDLINE | ID: mdl-33974708

ABSTRACT

BACKGROUND: No studies have explored the association between pneumococcal nasopharyngeal density and severe pneumonia using the World Health Organization (WHO) 2013 definition. In Lao People's Democratic Republic (Lao PDR), we determine the association between nasopharyngeal pneumococcal density and severe pneumonia in children. METHODS: A prospective observational study was undertaken at Mahosot Hospital, Vientiane, from 2014 to mid-2018. Children <5 years admitted with acute respiratory infections (ARIs) were included. Clinical and demographic data were collected alongside nasopharyngeal swabs for pneumococcal quantification by lytA real-time quantitative polymerase chain reaction. Severe pneumonia was defined using the 2013 WHO definition. For pneumococcal carriers, a logistic regression model examined the association between pneumococcal density and severe pneumonia, after adjusting for potential confounders including demographic and household factors, 13-valent pneumococcal conjugate vaccine status, respiratory syncytial virus co-detection, and preadmission antibiotics. RESULTS: Of 1268 participants with ARI, 32.3% (n = 410) had severe pneumonia and 36.9% (n = 468) had pneumococcal carriage. For pneumococcal carriers, pneumococcal density was positively associated with severe pneumonia (adjusted odds ratio, 1.4 [95% confidence interval, 1.1-1.8]; P = .020). CONCLUSIONS: Among children with ARIs and pneumococcal carriage, pneumococcal carriage density was positively associated with severe pneumonia in Lao PDR. Further studies may determine if pneumococcal density is a useful marker for pneumococcal conjugate vaccine impact on childhood pneumonia.


Subject(s)
Pneumococcal Infections , Pneumonia , Carrier State/epidemiology , Child , Child, Preschool , Cross-Sectional Studies , Humans , Infant , Laos/epidemiology , Nasopharynx , Pneumococcal Vaccines , Pneumonia/epidemiology , Serogroup
16.
Lancet Infect Dis ; 22(6): e176-e182, 2022 06.
Article in English | MEDLINE | ID: mdl-34953519

ABSTRACT

Melioidosis is a tropical infection caused by the soil bacterium Burkholderia pseudomallei. Despite the substantial impact of this often overlooked pathogen on both the health-care systems and economies of numerous low-income and middle-income countries around the world, melioidosis is not officially classified as a neglected tropical disease (NTD) by WHO. Melioidosis causes a higher estimated disease burden and mortality than many other recognised NTDs, with deaths primarily occurring among rural poor populations in low-income and middle-income countries. Fortunately, the impact of melioidosis in a region can be reduced once awareness is established of its known or suspected endemicity. In this Personal View, we provide evidence in support of official recognition of melioidosis as an NTD. We urge member states to request that WHO revisit their NTD list and appeal to government and philanthropic organisations to establish programmes in endemic countries to control melioidosis in order to reduce its global health burden.


Subject(s)
Burkholderia pseudomallei , Melioidosis , Cost of Illness , Global Health , Humans , Melioidosis/diagnosis , Melioidosis/epidemiology , Neglected Diseases/epidemiology
17.
Expert Rev Vaccines ; 21(8): 1137-1145, 2022 08.
Article in English | MEDLINE | ID: mdl-34378467

ABSTRACT

OBJECTIVES: Pneumococcal conjugate vaccines (PCVs) are effective in reducing pneumococcal disease. We measured 13-valent PCV (PCV13) effect on different pneumococcal outcomes using diverse studies in Lao People's Democratic Republic. METHODS: Studies included: pre-PCV13 population-based record review of hospitalized childhood pneumonia cases; acute respiratory infection (ARI) study post-PCV13 to demonstrate effectiveness (VE) against hypoxic pneumonia; invasive pneumococcal disease (IPD) surveillance in all ages (2004-2018); carriage studies in children hospitalized with ARI (2013-2019); community carriage surveys pre- and post-PCV13. RESULTS: Annual pneumonia incidence rate in children pre-PCV13 was 1,530 (95% confidence interval [CI] 1,477-1,584) per 100,000. Adjusted VE against hypoxic pneumonia was 37% (95% CI 6-57%). For IPD, 85% (11/13) of cases were due to vaccine-types pre-PCV13, and 43% (3/7) post-PCV13 in children aged <5 years; for ≥5 years, 61% (27/44) and 42% (17/40), respectively. For ARI cases, adjusted VE for vaccine-type carriage was 39% (95% CI 4-60) in <5 year olds; slightly higher than community surveys (23% [95% CI 4-39%] in 12-23 month olds). CONCLUSIONS: Despite limited baseline data, we found evidence of PCV13 impact on disease and carriage. Our approach could be used in similar settings to augment existing WHO PCV evaluation guidelines.


Subject(s)
Pneumococcal Infections , Respiratory Tract Infections , Child , Child, Preschool , Humans , Incidence , Infant , Pneumococcal Infections/epidemiology , Pneumococcal Infections/prevention & control , Pneumococcal Vaccines , Serogroup , Streptococcus pneumoniae , Vaccines, Conjugate
18.
Eur Radiol ; 32(2): 806-814, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34331118

ABSTRACT

OBJECTIVES: This study was designed to compare the detection of subtle lesions (calcification clusters or masses) when using the combination of digital breast tomosynthesis (DBT) and synthetic mammography (SM) with digital mammography (DM) alone or combined with DBT. METHODS: A set of 166 cases without cancer was acquired on a DBT mammography system. Realistic subtle calcification clusters and masses in the DM images and DBT planes were digitally inserted into 104 of the acquired cases. Three study arms were created: DM alone, DM with DBT and SM with DBT. Five mammographic readers located the centre of any lesion within the images that should be recalled for further investigation and graded their suspiciousness. A JAFROC figure of merit (FoM) and lesion detection fraction (LDF) were calculated for each study arm. The visibility of the lesions in the DBT images was compared with SM and DM images. RESULTS: For calcification clusters, there were no significant differences (p > 0.075) in FoM or LDF. For masses, the FoM and LDF were significantly improved in the arms using DBT compared to DM alone (p < 0.001). On average, both calcification clusters and masses were more visible on DBT than on DM and SM images. CONCLUSIONS: This study demonstrated that masses were detected better with DBT than with DM alone and there was no significant difference (p = 0.075) in LDF between DM&DBT and SM&DBT for calcifications clusters. Our results support previous studies that it may be acceptable to not acquire digital mammography alongside tomosynthesis for subtle calcification clusters and ill-defined masses. KEY POINTS: • The detection of masses was significantly better using DBT than with digital mammography alone. • The detection of calcification clusters was not significantly different between digital mammography and synthetic 2D images combined with tomosynthesis. • Our results support previous studies that it may be acceptable to not acquire digital mammography alongside tomosynthesis for subtle calcification clusters and ill-defined masses for the imaging technology used.


Subject(s)
Breast Neoplasms , Calcinosis , Neoplasms , Breast/diagnostic imaging , Breast Neoplasms/diagnostic imaging , Calcinosis/diagnostic imaging , Female , Humans , Mammography
19.
Emerg Infect Dis ; 28(1): 201-204, 2022 01.
Article in English | MEDLINE | ID: mdl-34757896

ABSTRACT

A 33-year-old man from Ghana who had diabetes had chronic osteomyelitis of the femoral shaft develop. Tissue samples from surgical debridement grew Burkholderia pseudomallei. He received meropenem, followed by oral trimethoprim/sulfamethoxazole and doxycycline, and fully recovered without complications. Our case report extends the range of countries in Africa as sources of culture-confirmed melioidosis.


Subject(s)
Burkholderia pseudomallei , Melioidosis , Osteomyelitis , Adult , Anti-Bacterial Agents/therapeutic use , Ghana , Humans , Male , Melioidosis/diagnosis , Melioidosis/drug therapy , Osteomyelitis/diagnosis , Osteomyelitis/drug therapy
20.
BMJ Glob Health ; 6(12)2021 11.
Article in English | MEDLINE | ID: mdl-34853032

ABSTRACT

OBJECTIVES: To review the scientific evidence base on antimicrobial use (AMU) and antimicrobial resistance (AMR) in human and animal sectors in the Lao PDR (Laos). METHODS: We reviewed all publications from July 1994 (the first article describing AMR in Laos) to December 2020. Electronic searches were conducted using Google Scholar and PubMed with specific terms relating to AMR and AMU in Lao, French and English languages. FINDINGS: We screened 1,357 peer-reviewed and grey reports by title and abstract and then full articles/reports. Of 80 included, 66 (83%) related to human health, nine (11%) to animal health, four (5%) to both animal and human health and one (1%) to the environment. Sixty-two (78%) were on AMR and 18 (22%) on AMU. Extended spectrum beta lactamase-producing Escherichia coli was the greatest concern identified; the proportion of isolates increased fivefold from 2004 to 2016 (2/28 (7%) to 27/78 (35%)) from blood cultures submitted to the Microbiology Laboratory, Mahosot Hospital, Vientiane. Carbapenem resistant Escherichia coli was first identified in 2015. Methicillin-resistant Staphylococcus aureus (MRSA) was uncommon, with 15 cases of MRSA from blood cultures between its first identification in 2017 and December 2020. AMR patterns of global antimicrobial resistance surveillance system (GLASS) target pathogens from livestock were less well documented. There were few data on AMU in human health and none on AMU in livestock. The first hospital AMU survey in Laos showed that 70% (1,386/1,981) of in-patients in five hospitals from 2017 to 2018 received antimicrobial(s). Antibiotic self-medication was common. CONCLUSION: AMR in Laos is occurring at relatively low proportions for some GLASS pathogens, giving the country a window of opportunity to act quickly to implement strategies to protect the population from a worsening situation. Urgent interventions to roll out new guidelines with enhanced one-health antibiotic stewardship, reduce antibiotic use without prescriptions, enhance surveillance and improve understanding of AMU and AMR are needed.


Subject(s)
Anti-Infective Agents , Methicillin-Resistant Staphylococcus aureus , Animals , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Drug Resistance, Bacterial , Humans , Language , Laos , Policy
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