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1.
PLOS Digit Health ; 2(4): e0000133, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37068064

ABSTRACT

In Burundi, the north-western region continues to grapple with the lowest level of antenatal care (ANC) attendance rate which is constantly about half the national average of 49% ANC4 coverage. Despite a dearth of empirical evidence to understand the determinants of this suboptimal attendance of ANC, widespread evidence informs that women forget scheduled ANC appointments. We designed and tested a digital intervention that uses a reminder model aimed at increasing the number of women who attend at least 4 ANC visits in this region. We enrolled a cohort of 132 pregnant women who were followed until childbirth using a single arm pre- and post-test design. The digital model builds on the collaboration between midwives or nurses, community health workers (CHWs), and pregnant women who are centrally connected through regular automated communications generated by the cPanel of the digital intervention. In addition to ANC attendances, we nested a cross-sectional survey to understand mothers' perceptions and acceptability of the digital intervention using the acceptability framework by Sekhon et al. (2017). Descriptive analyses were performed to observe the trend in ANC attendance and logistic regressions fitted to seize determinants affecting mothers' acceptability of the intervention. Of 132 enrolled pregnant women, 1 (0.76%) dropped out. From a baseline of 23%, nearly 73.7% of mothers attended their subsequent ANC visits after the start of the intervention. From the third month of intervention, about 80% of mothers constantly attended ANC appointments; which corresponds to greater than 200% increase from the baseline. Findings showed that 96.2% of mothers expressed satisfaction, 77.1% positively reacted to automated reminders (attitudes), 70.2% expressed willingness to participate, and 86.3% had the ability to actively participate to the intervention. Conversely, half of mothers confirmed that participation to this programme somewhat affected their time management. A key learning is that digital interventions have a lot of promise to improve pregnancy monitoring in rural settings. However, the overall user acceptability was low especially among mothers lacking personal mobile phone.

2.
Trop Med Infect Dis ; 7(9)2022 Aug 25.
Article in English | MEDLINE | ID: mdl-36136621

ABSTRACT

Thrombocytopenia and platelet dysfunction commonly occur in both dengue and COVID-19 and are related to clinical outcomes. Coagulation and fibrinolytic pathways are activated during an acute dengue infection, and endothelial dysfunction is observed in severe dengue. On the other hand, COVID-19 is characterised by a high prevalence of thrombotic complications, where bleeding is rare and occurs only in advanced stages of critical illness; here thrombin is the central mediator that activates endothelial cells, and elicits a pro-inflammatory reaction followed by platelet aggregation. Serological cross-reactivity may occur between COVID-19 and dengue infection. An important management aspect of COVID-19-induced immunothrombosis associated with thrombocytopenia is anticoagulation with or without aspirin. In contrast, the use of aspirin, nonsteroidal anti-inflammatory drugs and anticoagulants is contraindicated in dengue. Mild to moderate dengue infections are treated with supportive therapy and paracetamol for fever. Severe infection such as dengue haemorrhagic fever and dengue shock syndrome often require escalation to higher levels of support in a critical care facility. The role of therapeutic platelet transfusion is equivocal and should not be routinely used in patients with dengue with thrombocytopaenia and mild bleeding. The use of prophylactic platelet transfusion in dengue fever has strained financial and healthcare systems in endemic areas, together with risks of transfusion-transmitted infections in low- and middle-income countries. There is a clear research gap in the management of dengue with significant bleeding.

3.
Molecules ; 26(16)2021 Aug 18.
Article in English | MEDLINE | ID: mdl-34443589

ABSTRACT

The thrombotic thrombocytopenia syndrome (TTS), a complication of COVID-19 vaccines, involves thrombosis (often cerebral venous sinus thrombosis) and thrombocytopenia with occasional pulmonary embolism and arterial ischemia. TTS appears to mostly affect females aged between 20 and 50 years old, with no predisposing risk factors conclusively identified so far. Cases are characterized by thrombocytopenia, higher levels of D-dimers than commonly observed in venous thromboembolic events, inexplicably low fibrinogen levels and worsening thrombosis. Hyper fibrinolysis associated with bleeding can also occur. Antibodies that bind platelet factor 4, similar to those associated with heparin-induced thrombocytopenia, have also been identified but in the absence of patient exposure to heparin treatment. A number of countries have now suspended the use of adenovirus-vectored vaccines for younger individuals. The prevailing opinion of most experts is that the risk of developing COVID-19 disease, including thrombosis, far exceeds the extremely low risk of TTS associated with highly efficacious vaccines. Mass vaccination should continue but with caution. Vaccines that are more likely to cause TTS (e.g., Vaxzevria manufactured by AstraZeneca) should be avoided in younger patients for whom an alternative vaccine is available.


Subject(s)
COVID-19 Vaccines/adverse effects , Thrombocytopenia/chemically induced , Thrombocytopenia/therapy , Thrombosis/chemically induced , Thrombosis/therapy , Antibodies/blood , Diagnosis, Differential , Heparin/adverse effects , Humans , Platelet Factor 4/blood , Thrombocytopenia/etiology , Thrombosis/etiology
5.
J Public Health (Oxf) ; 43(4): e593-e600, 2021 12 10.
Article in English | MEDLINE | ID: mdl-32888030

ABSTRACT

BACKGROUND: Cancer patients diagnosed following an emergency presentation have poorer outcomes. We explore whether practice characteristics are associated with differences in the proportion of emergency presentations. METHODS: Univariable and multivariable logistic regression models were fitted to investigate the relationships between 2017-18 emergency cancer presentations at practice level in England and access and continuity in primary care, trust in healthcare professionals, 2-week-wait (2WW) referrals, quality and outcomes framework (QOF) achievements and socio-demographic factors (age, gender and deprivation). RESULTS: Our analysis using comprehensive nationwide data found that the following practice level factors have significant associations with a lower proportion of emergency diagnosis of cancer: increased trust and confidence in the practice healthcare professionals; higher 2WW referral and conversion rate; higher total practice QOF score and higher satisfaction with appointment times or higher proportion able to see preferred GP. Our results also show that practices in more deprived areas are significantly associated with a higher proportion of emergency diagnoses of cancer. CONCLUSIONS: Regional cancer networks should focus their efforts in increasing both the quantity and appropriateness of 2WW referrals from primary care. In addition, primary care clinicians should be supported to undertake high quality consultations, thus building trust with patients and ensuring continuity of care.


Subject(s)
General Practice , Neoplasms , Appointments and Schedules , Humans , Neoplasms/diagnosis , Neoplasms/epidemiology , Neoplasms/therapy , Referral and Consultation , Trust
6.
J Comput Aided Mol Des ; 30(11): 1115-1127, 2016 11.
Article in English | MEDLINE | ID: mdl-27585474

ABSTRACT

Implicit solvent methods for classical molecular modeling are frequently used to provide fast, physics-based hydration free energies of macromolecules. Less commonly considered is the transferability of these methods to other solvents. The Statistical Assessment of Modeling of Proteins and Ligands 5 (SAMPL5) distribution coefficient dataset and the accompanying explicit solvent partition coefficient reference calculations provide a direct test of solvent model transferability. Here we use the 3D reference interaction site model (3D-RISM) statistical-mechanical solvation theory, with a well tested water model and a new united atom cyclohexane model, to calculate partition coefficients for the SAMPL5 dataset. The cyclohexane model performed well in training and testing ([Formula: see text] for amino acid neutral side chain analogues) but only if a parameterized solvation free energy correction was used. In contrast, the same protocol, using single solute conformations, performed poorly on the SAMPL5 dataset, obtaining [Formula: see text] compared to the reference partition coefficients, likely due to the much larger solute sizes. Including solute conformational sampling through molecular dynamics coupled with 3D-RISM (MD/3D-RISM) improved agreement with the reference calculation to [Formula: see text]. Since our initial calculations only considered partition coefficients and not distribution coefficients, solute sampling provided little benefit comparing against experiment, where ionized and tautomer states are more important. Applying a simple [Formula: see text] correction improved agreement with experiment from [Formula: see text] to [Formula: see text], despite a small number of outliers. Better agreement is possible by accounting for tautomers and improving the ionization correction.


Subject(s)
Computer Simulation , Cyclohexanes/chemistry , Pharmaceutical Preparations/chemistry , Solvents/chemistry , Water/chemistry , Isomerism , Models, Chemical , Molecular Conformation , Solubility , Thermodynamics
7.
Int J Syst Evol Microbiol ; 64(Pt 9): 2944-2948, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24899653

ABSTRACT

A polyphasic study was undertaken to determine the taxonomic position of 13 Campylobacter fetus-like strains from humans (n = 8) and reptiles (n = 5). The results of matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) MS and genomic data from sap analysis, 16S rRNA gene and hsp60 sequence comparison, pulsed-field gel electrophoresis, amplified fragment length polymorphism analysis, DNA-DNA hybridization and whole genome sequencing demonstrated that these strains are closely related to C. fetus but clearly differentiated from recognized subspecies of C. fetus. Therefore, this unique cluster of 13 strains represents a novel subspecies within the species C. fetus, for which the name Campylobacter fetus subsp. testudinum subsp. nov. is proposed, with strain 03-427(T) ( = ATCC BAA-2539(T) = LMG 27499(T)) as the type strain. Although this novel taxon could not be differentiated from C. fetus subsp. fetus and C. fetus subsp. venerealis using conventional phenotypic tests, MALDI-TOF MS revealed the presence of multiple phenotypic biomarkers which distinguish Campylobacter fetus subsp. testudinum subsp. nov. from recognized subspecies of C. fetus.


Subject(s)
Campylobacter fetus/classification , Phylogeny , Reptiles/microbiology , Amplified Fragment Length Polymorphism Analysis , Animals , Bacterial Typing Techniques , Campylobacter fetus/genetics , Campylobacter fetus/isolation & purification , DNA, Bacterial/genetics , Humans , Molecular Sequence Data , Nucleic Acid Hybridization , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
8.
Appl Environ Microbiol ; 80(15): 4540-6, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24837383

ABSTRACT

From August to September 2008, the Centers for Disease Control and Prevention (CDC) assisted the Alaska Division of Public Health with an outbreak investigation of campylobacteriosis occurring among the residents of Southcentral Alaska. During the investigation, pulsed-field gel electrophoresis (PFGE) of Campylobacter jejuni isolates from human, raw pea, and wild bird fecal samples confirmed the epidemiologic link between illness and the consumption of raw peas contaminated by sandhill cranes for 15 of 43 epidemiologically linked human isolates. However, an association between the remaining epidemiologically linked human infections and the pea and wild bird isolates was not established. To better understand the molecular epidemiology of the outbreak, C. jejuni isolates (n=130; 59 from humans, 40 from peas, and 31 from wild birds) were further characterized by multilocus sequence typing (MLST). Here we present the molecular evidence to demonstrate the association of many more human C.jejuni infections associated with the outbreak with raw peas and wild bird feces. Among all sequence types (STs) identified, 26 of 39 (67%) were novel and exclusive to the outbreak. Five clusters of overlapping STs (n=32 isolates; 17 from humans, 2 from peas, and 13 from wild birds) were identified. In particular, cluster E (n=7 isolates; ST-5049) consisted of isolates from humans,peas, and wild birds. Novel STs clustered closely with isolates typically associated with wild birds and the environment but distinct from lineages commonly seen in human infections. Novel STs and alleles recovered from human outbreak isolates allowed additional infections caused by these rare genotypes to be attributed to the contaminated raw peas.


Subject(s)
Animals, Wild/microbiology , Birds/microbiology , Campylobacter Infections/microbiology , Campylobacter/isolation & purification , Pisum sativum/microbiology , Alaska/epidemiology , Animals , Campylobacter/classification , Campylobacter/genetics , Campylobacter Infections/epidemiology , Disease Outbreaks , Feces/microbiology , Food Contamination/analysis , Genotype , Humans , Molecular Sequence Data , Multilocus Sequence Typing , Phylogeny
9.
PLoS Negl Trop Dis ; 8(3): e2726, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24603860

ABSTRACT

BACKGROUND: Salmonella enterica serovar Typhi is transmitted by fecally contaminated food and water and causes approximately 22 million typhoid fever infections worldwide each year. Most cases occur in developing countries, where approximately 4% of patients develop intestinal perforation (IP). In Kasese District, Uganda, a typhoid fever outbreak notable for a high IP rate began in 2008. We report that this outbreak continued through 2011, when it spread to the neighboring district of Bundibugyo. METHODOLOGY/PRINCIPAL FINDINGS: A suspected typhoid fever case was defined as IP or symptoms of fever, abdominal pain, and ≥1 of the following: gastrointestinal disruptions, body weakness, joint pain, headache, clinically suspected IP, or non-responsiveness to antimalarial medications. Cases were identified retrospectively via medical record reviews and prospectively through laboratory-enhanced case finding. Among Kasese residents, 709 cases were identified from August 1, 2009-December 31, 2011; of these, 149 were identified during the prospective period beginning November 1, 2011. Among Bundibugyo residents, 333 cases were identified from January 1-December 31, 2011, including 128 cases identified during the prospective period beginning October 28, 2011. IP was reported for 507 (82%) and 59 (20%) of Kasese and Bundibugyo cases, respectively. Blood and stool cultures performed for 154 patients during the prospective period yielded isolates from 24 (16%) patients. Three pulsed-field gel electrophoresis pattern combinations, including one observed in a Kasese isolate in 2009, were shared among Kasese and Bundibugyo isolates. Antimicrobial susceptibility was assessed for 18 isolates; among these 15 (83%) were multidrug-resistant (MDR), compared to 5% of 2009 isolates. CONCLUSIONS/SIGNIFICANCE: Molecular and epidemiological evidence suggest that during a prolonged outbreak, typhoid spread from Kasese to Bundibugyo. MDR strains became prevalent. Lasting interventions, such as typhoid vaccination and improvements in drinking water infrastructure, should be considered to minimize the risk of prolonged outbreaks in the future.


Subject(s)
Disease Outbreaks , Drug Resistance, Bacterial , Salmonella typhi/drug effects , Topography, Medical , Typhoid Fever/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Anti-Bacterial Agents/pharmacology , Blood/microbiology , Child , Child, Preschool , Cluster Analysis , Electrophoresis, Gel, Pulsed-Field , Feces/microbiology , Female , Humans , Infant , Male , Microbial Sensitivity Tests , Middle Aged , Molecular Typing , Salmonella typhi/classification , Salmonella typhi/genetics , Salmonella typhi/isolation & purification , Typhoid Fever/pathology , Uganda/epidemiology , Young Adult
10.
PLoS One ; 8(10): e77836, 2013.
Article in English | MEDLINE | ID: mdl-24204990

ABSTRACT

Salmonellosis is one of the most important foodborne diseases affecting humans. To characterize the relationship between Salmonella causing human infections and their food animal reservoirs, we compared pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility patterns of non-typhoidal Salmonella isolated from ill humans in Pennsylvania and from food animals before retail. Human clinical isolates were received from 2005 through 2011 during routine public health operations in Pennsylvania. Isolates from cattle, chickens, swine and turkeys were recovered during the same period from federally inspected slaughter and processing facilities in the northeastern United States. We found that subtyping Salmonella isolates by PFGE revealed differences in antimicrobial susceptibility patterns and, for human Salmonella, differences in sources and invasiveness that were not evident from serotyping alone. Sixteen of the 20 most common human Salmonella PFGE patterns were identified in Salmonella recovered from food animals. The most common human Salmonella PFGE pattern, Enteritidis pattern JEGX01.0004 (JEGX01.0003ARS), was associated with more cases of invasive salmonellosis than all other patterns. In food animals, this pattern was almost exclusively (99%) found in Salmonella recovered from chickens and was present in poultry meat in every year of the study. Enteritidis pattern JEGX01.0004 (JEGX01.0003ARS) was associated with susceptibility to all antimicrobial agents tested in 94.7% of human and 97.2% of food animal Salmonella isolates. In contrast, multidrug resistance (resistance to three or more classes of antimicrobial agents) was observed in five PFGE patterns. Typhimurium patterns JPXX01.0003 (JPXX01.0003 ARS) and JPXX01.0018 (JPXX01.0002 ARS), considered together, were associated with resistance to five or more classes of antimicrobial agents: ampicillin, chloramphenicol, streptomycin, sulfonamides and tetracycline (ACSSuT), in 92% of human and 80% of food animal Salmonella isolates. The information from our study can assist in source attribution, outbreak investigations, and tailoring of interventions to maximize their impact on prevention.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Food Microbiology , Meat Products/microbiology , Salmonella Infections/diagnosis , Salmonella/physiology , Animals , Cattle/microbiology , Chickens/microbiology , Electrophoresis, Gel, Pulsed-Field , Humans , Microbial Sensitivity Tests , Salmonella/isolation & purification , Salmonella Infections/microbiology , Swine/microbiology , Turkeys/microbiology
11.
Foodborne Pathog Dis ; 10(4): 302-9, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23464603

ABSTRACT

BACKGROUND: Salmonella is a major bacterial pathogen transmitted commonly through food. Increasing resistance to antimicrobial agents (e.g., ceftriaxone, ciprofloxacin) used to treat serious Salmonella infections threatens the utility of these agents. Infection with antimicrobial-resistant Salmonella has been associated with increased risk of severe infection, hospitalization, and death. We describe changes in antimicrobial resistance among nontyphoidal Salmonella in the United States from 1996 through 2009. METHODS: The Centers for Disease Control and Prevention's National Antimicrobial Resistance Monitoring System conducts surveillance of resistance among Salmonella isolated from humans. From 1996 through 2009, public health laboratories submitted isolates for antimicrobial susceptibility testing. We used interpretive criteria from the Clinical and Laboratory Standards Institute and defined isolates with ciprofloxacin resistance or intermediate susceptibility as nonsusceptible to ciprofloxacin. Using logistic regression, we modeled annual data to assess changes in antimicrobial resistance. RESULTS: From 1996 through 2009, the percentage of nontyphoidal Salmonella isolates resistant to ceftriaxone increased from 0.2% to 3.4% (odds ratio [OR]=20, 95% confidence interval [CI] 6.3-64), and the percentage with nonsusceptibility to ciprofloxacin increased from 0.4% to 2.4% (OR=8.3, 95% CI 3.3-21). The percentage of isolates that were multidrug resistant (resistant to ≥3 antimicrobial classes) decreased from 17% to 9.6% (OR=0.6, 95% CI 0.5-0.7), which was driven mainly by a decline among serotype Typhimurium. However, multidrug resistance increased from 5.9% in 1996 to a peak of 31% in 2001 among serotype Newport and increased from 12% in 1996 to 26% in 2009 (OR=2.6, 95% CI 1.1-6.2) among serotype Heidelberg. CONCLUSIONS: We describe an increase in resistance to ceftriaxone and nonsusceptibility to ciprofloxacin and an overall decline in multidrug resistance. Trends varied by serotype. Because of evidence that antimicrobial resistance among Salmonella is predominantly a consequence of antimicrobial use in food animals, efforts are needed to reduce unnecessary use, especially of critically important agents.


Subject(s)
Ceftriaxone/pharmacology , Ciprofloxacin/pharmacology , Drug Resistance, Multiple, Bacterial , Salmonella/drug effects , Adolescent , Adult , Animals , Anti-Bacterial Agents/pharmacology , Child , Child, Preschool , Female , Humans , Infant , Male , Microbial Sensitivity Tests , Middle Aged , Salmonella/isolation & purification , Salmonella Infections/epidemiology , Salmonella Infections/microbiology , United States/epidemiology , Young Adult
12.
Clin Infect Dis ; 54 Suppl 5: S458-63, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22572670

ABSTRACT

BACKGROUND: Treatment of shigellosis with appropriate antimicrobial agents shortens duration of illness and bacterial shedding, but resistance to commonly used agents is increasing. METHODS: We describe resistance patterns among Shigella isolates in the United States with use of linked data from the Foodborne Diseases Active Surveillance Network (FoodNet) and National Antimicrobial Resistance Monitoring System (NARMS). FoodNet sites send every 20th Shigella isolate to the NARMS laboratory for susceptibility testing. RESULTS: During 2000-2010, the NARMS laboratory tested 1376 Shigella isolates from FoodNet sites. Of 1118 isolates (81%) linked to FoodNet, 826 (74%) were resistant to ampicillin, 649 (58%) to streptomycin, 402 (36%) to trimethoprim-sulfamethoxazole (TMP-SMX), 355 (32%) to sulfamethoxazole-sulfisoxazole, 312 (28%) to tetracycline, 19 (2%) to nalidixic acid, and 6 (0.5%) to ciprofloxacin. The proportion of Shigella isolates with resistance to TMP-SMX was 40% among white persons, 58% among Hispanic persons, and 75% among persons with a history of international travel. Resistance to at least TMP-SMX and ampicillin was present in 25% of isolate, and 5% were resistant to ampicillin, TMP-SMX, and chloramphenicol. Overall, 5% of isolates showed multidrug resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole-sulfisoxazole, and tetracycline, including 49 Shigella flexneri (33%) and 3 Shigella sonnei (0.3%) isolates. Male individuals were more likely than female individuals to be infected with a multidrug-resistant strain (7% versus 3%; P < .01). CONCLUSIONS: Antimicrobial resistance differed by race, ethnicity, age, travel, and species. Resistance to commonly used antibiotics is high; therefore, it is important to look at the susceptibility pattern before starting treatment.


Subject(s)
Anti-Infective Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Dysentery, Bacillary/microbiology , Foodborne Diseases/microbiology , Shigella/drug effects , Shigella/isolation & purification , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Centers for Disease Control and Prevention, U.S. , Child , Child, Preschool , Dysentery, Bacillary/ethnology , Female , Foodborne Diseases/ethnology , Hispanic or Latino , Humans , Infant , Male , Microbial Sensitivity Tests , Middle Aged , Travel , United States , White People , Young Adult
13.
Clin Infect Dis ; 54(8): 1100-6, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22357702

ABSTRACT

BACKGROUND: Salmonella enterica serovar Typhi causes an estimated 22 million cases of typhoid fever and 216 000 deaths annually worldwide. We investigated an outbreak of unexplained febrile illnesses with neurologic findings, determined to be typhoid fever, along the Malawi-Mozambique border. METHODS: The investigation included active surveillance, interviews, examinations of ill and convalescent persons, medical chart reviews, and laboratory testing. Classification as a suspected case required fever and ≥1 other finding (eg, headache or abdominal pain); a probable case required fever and a positive rapid immunoglobulin M antibody test for typhoid (TUBEX TF); a confirmed case required isolation of Salmonella Typhi from blood or stool. Isolates underwent antimicrobial susceptibility testing and subtyping by pulsed-field gel electrophoresis (PFGE). RESULTS: We identified 303 cases from 18 villages with onset during March-November 2009; 214 were suspected, 43 were probable, and 46 were confirmed cases. Forty patients presented with focal neurologic abnormalities, including a constellation of upper motor neuron signs (n = 19), ataxia (n = 22), and parkinsonism (n = 8). Eleven patients died. All 42 isolates tested were resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole; 4 were also resistant to nalidixic acid. Thirty-five of 42 isolates were indistinguishable by PFGE. CONCLUSIONS: The unusual neurologic manifestations posed a diagnostic challenge that was resolved through rapid typhoid antibody testing in the field and subsequent blood culture confirmation in the Malawi national reference laboratory. Extending laboratory diagnostic capacity, including blood culture, to populations at risk for typhoid fever in Africa will improve outbreak detection, response, and clinical treatment.


Subject(s)
Disease Outbreaks , Drug Resistance, Multiple, Bacterial , Nervous System Diseases/epidemiology , Salmonella typhi/drug effects , Typhoid Fever/complications , Typhoid Fever/diagnosis , Typhoid Fever/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies, Bacterial/blood , Child , Child, Preschool , Electrophoresis, Gel, Pulsed-Field , Female , Fever/diagnosis , Fever/etiology , Humans , Immunoglobulin M/blood , Infant , Malawi/epidemiology , Male , Microbial Sensitivity Tests , Middle Aged , Molecular Typing , Mozambique/epidemiology , Nervous System Diseases/etiology , Salmonella typhi/classification , Salmonella typhi/genetics , Salmonella typhi/isolation & purification , Typhoid Fever/microbiology , Young Adult
14.
Radiat Prot Dosimetry ; 149(3): 251-67, 2012 Apr.
Article in English | MEDLINE | ID: mdl-21693467

ABSTRACT

In making low-level radioactivity measurements of populations, it is commonly observed that a substantial portion of net results is negative. Furthermore, the observed variance of the measurement results arises from a combination of measurement uncertainty and population variability. This paper presents a method for disaggregating measurement uncertainty from population variability to produce a probability density function (PDF) of possibly true results. To do this, simple, justifiable and reasonable assumptions are made about the relationship of the measurements to the measurands (the 'true values'). The measurements are assumed to be unbiased, that is, that their average value is the average of the measurands. Using traditional estimates of each measurement's uncertainty, a likelihood PDF for each individual's measurand is produced. Then using the same assumptions and all the data from the population of individuals, a prior PDF of measurands for the population is produced. The prior PDF is non-negative, and the average is equal to the average of the measurement results for the population. Using Bayes's theorem, posterior PDFs of each individual measurand are calculated. The uncertainty in these bayesian posterior PDFs appears to be all Berkson with no remaining classical component. The method is applied to baseline bioassay data from the Hanford site. The data include (90)Sr urinalysis measurements of 128 people, (137)Cs in vivo measurements of 5337 people and (239)Pu urinalysis measurements of 3270 people. The method produces excellent results for the (90)Sr and (137)Cs measurements, since there are non-zero concentrations of these global fallout radionuclides in people who have not been occupationally exposed. The method does not work for the (239)Pu measurements in non-occupationally exposed people because the population average is essentially zero relative to the sensitivity of the measurement technique. The method is shown to give results similar to classical statistical inference when the measurements have relatively small uncertainty.


Subject(s)
Biological Assay/methods , Radiometry/methods , Algorithms , Bayes Theorem , Cesium Radioisotopes/chemistry , Data Interpretation, Statistical , Environmental Exposure , Humans , Isotopes/analysis , Models, Statistical , Plutonium/analysis , Probability , Radiation Dosage , Regression Analysis , Strontium Radioisotopes/chemistry , Uncertainty
15.
Emerg Infect Dis ; 17(11): 2122-9, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22099116

ABSTRACT

In October 2010, the US Centers for Disease Control and Prevention received reports of cases of severe watery diarrhea in Haiti. The cause was confirmed to be toxigenic Vibrio cholerae, serogroup O1, serotype Ogawa, biotype El Tor. We characterized 122 isolates from Haiti and compared them with isolates from other countries. Antimicrobial drug susceptibility was tested by disk diffusion and broth microdilution. Analyses included identification of rstR and VC2346 genes, sequencing of ctxAB and tcpA genes, and pulsed-field gel electrophoresis with SfiI and NotI enzymes. All isolates were susceptible to doxycycline and azithromycin. One pulsed-field gel electrophoresis pattern predominated, and ctxB sequence of all isolates matched the B-7 allele. We identified the tcpETCIRS allele, which is also present in Bangladesh strain CIRS 101. These data show that the isolates from Haiti are clonally and genetically similar to isolates originating in Africa and southern Asia and that ctxB-7 and tcpET(CIRS) alleles are undergoing global dissemination.


Subject(s)
Vibrio cholerae/genetics , Vibrio cholerae/pathogenicity , Alleles , Bacterial Typing Techniques , Cholera/epidemiology , Cholera Toxin/genetics , Disease Outbreaks , Electrophoresis, Gel, Pulsed-Field , Genotype , Haiti/epidemiology , Humans , Microbial Sensitivity Tests , Vibrio cholerae/classification , Virulence , Virulence Factors/genetics
16.
Emerg Infect Dis ; 17(11): 2151-4, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22099122

ABSTRACT

To increase understanding of drug-resistant Vibrio cholerae, we studied selected molecular mechanisms of antimicrobial drug resistance in the 2010 Haiti V. cholerae outbreak strain. Most resistance resulted from acquired genes located on an integrating conjugative element showing high homology to an integrating conjugative element identified in a V. cholerae isolate from India.


Subject(s)
Cholera/epidemiology , Disease Outbreaks , Drug Resistance, Multiple, Bacterial , Vibrio cholerae O1/drug effects , Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial/genetics , Gene Order , Genome, Bacterial , Haiti/epidemiology , Humans , Microbial Sensitivity Tests , Phylogeny , Vibrio cholerae O1/genetics , Vibrio cholerae O1/isolation & purification
17.
Emerg Infect Dis ; 17(6): 1095-8, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21749779

ABSTRACT

We report 9 ciprofloxacin-resistant Salmonella enterica serotype Typhi isolates submitted to the US National Antimicrobial Resistance Monitoring System during 1999-2008. The first 2 had indistinguishable pulsed-field gel electrophoresis patterns and identical gyrA and parC mutations. Eight of the 9 patients had traveled to India within 30 days before illness onset.


Subject(s)
Anti-Bacterial Agents/pharmacology , Ciprofloxacin/pharmacology , Salmonella typhi/drug effects , Typhoid Fever/epidemiology , Typhoid Fever/microbiology , Adolescent , Adult , Child , Child, Preschool , DNA Gyrase/genetics , DNA Topoisomerase IV/genetics , Drug Resistance, Bacterial/genetics , Female , Gene Expression Regulation, Bacterial/drug effects , Humans , Infant , Male , Microbial Sensitivity Tests , Middle Aged , Mutation/genetics , Salmonella typhi/genetics , Salmonella typhi/isolation & purification , United States/epidemiology , Young Adult
18.
Antimicrob Agents Chemother ; 55(9): 3985-9, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21690279

ABSTRACT

Due to emerging resistance to traditional antimicrobial agents, such as ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol, azithromycin is increasingly used for the treatment of invasive Salmonella infections. In the present study, 696 isolates of non-Typhi Salmonella collected from humans, food animals, and retail meats in the United States were investigated for antimicrobial susceptibility to azithromycin. Seventy-two Salmonella enterica serotype Typhi isolates from humans were also tested. For each isolate, MICs of azithromycin and 15 other antimicrobial agents were determined by broth microdilution. Among the non-Typhi Salmonella isolates, azithromycin MICs among human isolates ranged from 1 to 32 µg/ml, whereas the MICs among the animal and retail meat isolates ranged from 2 to 16 µg/ml and 4 to 16 µg/ml, respectively. Among Salmonella serotype Typhi isolates, the azithromycin MICs ranged from 4 to 16 µg/ml. The highest MIC observed in the present study was 32 µg/ml, and it was detected in three human isolates belonging to serotypes Kentucky, Montevideo, and Paratyphi A. Based on our findings, we propose an epidemiological cutoff value (ECOFF) for wild-type Salmonella of ≤16 µg/ml of azithromycin. The susceptibility data provided could be used in combination with clinical outcome data to determine tentative clinical breakpoints for azithromycin and Salmonella enterica.


Subject(s)
Anti-Bacterial Agents/pharmacology , Azithromycin/pharmacology , Salmonella enterica/drug effects , Animals , Humans , Microbial Sensitivity Tests , United States
19.
Antimicrob Agents Chemother ; 55(3): 1148-54, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21199924

ABSTRACT

Nontyphoidal salmonellae (NTS) are important causes of community-acquired bloodstream infection. We describe patterns of antimicrobial resistance among invasive NTS in the United States. We compared bloodstream NTS isolates with those from stool submitted to the National Antimicrobial Resistance Monitoring System (NARMS) from 1996 to 2007. We describe antimicrobial resistance among invasive strains by serogroup and serotype. Of the 19,302 NTS isolates, 17,804 (92.2%) were from stool or blood. Of these, 1,050 (5.9%) were bloodstream isolates. The median ages (ranges) of patients with and without bacteremia were 36 (<1 to 97) years and 20 (<1 to 105) years, respectively (P < 0.001). Males (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.06 to 1.38) and those ≥65 years of age were at greater risk for invasive disease. Salmonella enterica serotypes Enteritidis, Typhimurium, and Heidelberg were the most common serotypes isolated from blood; S. enterica serotypes Dublin, Sandiego, and Schwarzengrund were associated with the greatest risk for bloodstream isolation. Of invasive isolates, 208 (19.8%) were resistant to ampicillin, 117 (11.1%) to chloramphenicol, and 26 (2.5%) to trimethoprim-sulfamethoxazole; 28 (2.7%) isolates were resistant to nalidixic acid and 26 (2.5%) to ceftriaxone. Antimicrobial resistance to traditional agents is common. However, the occurrence of nalidixic acid and ceftriaxone resistance among invasive NTS is cause for clinical and public health vigilance.


Subject(s)
Salmonella enterica/drug effects , Adolescent , Adult , Aged , Aged, 80 and over , Ampicillin/therapeutic use , Anti-Bacterial Agents/therapeutic use , Bacteremia/drug therapy , Bacteremia/microbiology , Ceftriaxone/therapeutic use , Child , Child, Preschool , Chloramphenicol/therapeutic use , Community-Acquired Infections/drug therapy , Female , Humans , Infant , Male , Microbial Sensitivity Tests , Middle Aged , Nalidixic Acid/therapeutic use , Salmonella Infections/microbiology , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , United States , Young Adult
20.
Foodborne Pathog Dis ; 8(2): 329-32, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20973731

ABSTRACT

To increase understanding of community-acquired resistance, stool samples from 477 nonhospitalized persons in Maryland and Michigan, from 2004 to 2008, were screened for ceftriaxone resistance. Seven (1.5%) yielded ceftriaxone-resistant Escherichia coli; one isolate was resistant to all eight antimicrobial classes routinely tested: aminoglycosides, ß-lactam/ß-lactamase inhibitor combinations, cephems, penicillins, folate pathway inhibitors, phenicols, quinolones, and tetracyclines. The extensively resistant isolate was from a 50-year-old woman who denied antimicrobial use, hospitalization, or international travel within 6 months. Meat (beef, chicken, and pork) and eggs were consumed within 1 month before stool collection. Further studies are warranted to understand potential sources, including the food supply, of resistant E. coli.


Subject(s)
Drug Resistance, Multiple, Bacterial , Escherichia coli/drug effects , Escherichia coli/genetics , Adult , Animals , Ceftriaxone/pharmacology , Drug Resistance, Multiple, Bacterial/genetics , Escherichia coli/isolation & purification , Feces/microbiology , Female , Genes, Bacterial , Genes, MDR , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Plasmids/genetics , Plasmids/isolation & purification , Population Surveillance , Surveys and Questionnaires , United States
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