Challenges in LTBI care in the United States identified using a nationwide TB medical consultation database.

BACKGROUND: Identifying and treating individuals with latent TB infection (LTBI) represents a critical and challenging component of national TB elimination. Medical consultations by the Centers for Disease Control and Prevention (CDC) funded TB Centers of Excellence (COEs) are an important resource for healthcare professionals (HCPs) caring for individuals with LTBI. This study aimed to identify the most common clinical concerns regarding LTBI care and to describe epidemiologic and clinical features of patients discussed in these consultations. METHODS: This mixed-methods study randomly sampled 125 consultation inquiries related to LTBI from the COEs' medical consultation database in 2018. Text from consultation records were reviewed and coded to identify reasons for the inquiries and common epidemiologic and clinical patient characteristics. RESULTS: The most common topics of inquiry for consultation included accurate LTBI diagnosis (36%), management of LTBI treatment-related issues (22%), and choice of appropriate LTBI treatment regimen (17%). Patients for whom consultations were requested commonly had another medical condition (34%), were non-U.S. born (31%), were children (25%), and had a history of travel to TB-endemic areas (18%). CONCLUSION: Our findings emphasize the challenge of managing patients with either suspected or confirmed LTBI, highlighting the need for ongoing medical consultation support for nuanced clinical and epidemiologic scenarios.

CONTEXTE: L'identification et le traitement des personnes atteintes d'infection tuberculeuse latente (LTBI) sont des composantes essentielles et difficiles de la stratégie nationale d'élimination de la TB. Les consultations médicales des TB Centers of Excellence (COE), financés par les Centres pour le contrôle et la prévention des maladies (CDC), sont d'importantes ressources pour les professionnels de santé qui prennent en charge les personnes atteintes de LTBI. Cette étude avait pour objectif d'identifier les problèmes cliniques les plus fréquents en matière de prise en charge de la LTBI, et de décrire les caractéristiques épidémiologiques et cliniques des patients évoquées lors de ces consultations. MÉTHODES: Cette étude à méthodes mixtes a sélectionné de manière aléatoire 125 demandes de consultations relatives à la LTBI à partir de la base de données des consultations médicales du COE en 2018. Les notes des dossiers de consultation ont été revues et codées pour identifier les raisons des demandes, ainsi que les caractéristiques cliniques et épidémiologiques fréquentes des patients. RÉSULTATS: Les raisons les plus fréquentes de demandes de consultation étaient diagnostic précis de LTBI (36%), prise en charge des problèmes liés au traitement de la LTBI (22%) et choix d'un schéma thérapeutique approprié de la LTBI (17%). Les patients pour lesquels des consultations étaient demandées avaient fréquemment une autre pathologie (34%), n'étaient pas nés aux États-Unis (31%), étaient des enfants (25%) et avaient des antécédents de voyage dans des zones où la TB est endémique (18%). CONCLUSION: Nos résultats mettent l'accent sur les défis de la prise en charge des patients avec une LTBI présumée ou confirmée, soulignant le besoin d'aide continue aux consultations médicales pour des scénarios épidémiologiques et cliniques nuancés.

Multidrug-resistant tuberculosis care in the United States.

BACKGROUND: To examine the utilization of the Tuberculosis (TB) Centers of Excellence (COE) medical consultation service and evaluate how these services were being employed for patients in relation to multidrug-resistant TB (MDR-TB).METHODS: Medical consults are documented in a secure database. The database was queried for MDR-TB consultations over the period 1 January 2013-31 December 2017. All were analyzed to assess provider type, center, setting, year of call, and type of patient (pediatric vs. adult). A subgroup was randomly selected for thematic analysis.RESULTS: The centers received 1560 MDR-TB consultation requests over this period. Providers requesting consults were primarily physicians (55%). The majority of requests were from public health departments (64%) and for adult patients (80%). Four major topic areas emerged: 1) initial management of MDR-TB, 2) MDR-TB longitudinal treatment and complications, 3) management of persons exposed to MDR-TB, and 4) MDR-TB treatment completion.CONCLUSIONS: Analysis of these consultations provides insight into the type of expert advice about MDR-TB that was provided. These findings highlight topics where increased medical training and education may help to improve MDR-TB-related practices.

Successful use of rifampicin for Hispanic foreign-born patients with latent tuberculosis infection.

SETTING: Four months of rifampicin (4R) is recommended for the treatment of latent tuberculosis infection (LTBI), although data regarding its use are limited. The majority of tuberculosis (TB) cases in the USA occur among foreign-born persons. OBJECTIVE: To determine tolerability, hepatotoxicity and completion rates associated with 4R among foreign-born persons. DESIGN: We retrospectively evaluated 4R treatment among a cohort of predominantly Hispanic foreign-born LTBI patients in four Middle-Tennessee public health clinics from February 2000 to February 2004. Patients' charts were reviewed to abstract demographic, social and clinical data. 4R completion rates, new symptoms and hepatotoxicity (serum aminoalanine transferase >or=120U/l with gastrointestinal symptoms or >or=200 regardless of symptoms) were evaluated. RESULTS: Of 749 patients treated, 571 (76%) completed 4R. Among all subjects, Hispanics had a lower risk of non-completion (OR 0.6, 95%CI 0.4-0.7) than non-Hispanics. Among non-Hispanic subjects, the risk of non-completion was higher for Blacks than non-Blacks (adjusted OR 2.6, 95%CI 1.5-4.7), but was lower for foreign-born than non-foreign-born subjects (adjusted OR 0.5, 95%CI 0.2-0.9). During treatment, 85 subjects (11%) developed new symptoms, and hepatotoxicity occurred in three patients. CONCLUSION: With high completion rates and minimal side effects, 4R is a favorable LTBI treatment regimen for Hispanic and other foreign-born patients.

Antimicrobial susceptibility of Clostridium difficile isolated from food animals on farms.

Clostridium difficile is commonly associated with a spectrum of disease in humans referred to as C. difficile-associated disease (CDAD) and use of antimicrobials is considered a risk factor for development of disease in humans. C. difficile can also inhabit healthy food animals and transmission to humans is possible. As a result of the complexity and cost of testing, C. difficile is rarely tested for antimicrobial susceptibility. A total of 376 C. difficile strains (94 each from swine and dairy feces, and 188 from beef cattle feces) were isolated from healthy food animals on farms during studies conducted by the National Animal Health Monitoring System. Using the Etest (AB Biodisk, Solna, Sweden), samples were tested for susceptibility to nine antimicrobials implicated as risk factors for CDAD (linezolid, amoxicillin-clavulanic acid, ampicillin, clindamycin, erythromycin, levofloxacin, metronidazole, rifampicin, and vancomycin). Vancomycin was active against all isolates of C. difficile (MIC90=3.0µg/ml) while almost all isolates (n=369; 98.1%) were resistant to levofloxacin. With the exception of vancomycin, resistance varied by animal species as follows: linezolid (8.5% resistance among swine versus 2.1 and 1.1% resistance among dairy and beef, respectively), clindamycin (56.4% resistance among swine versus 80% and 90.9% resistance among dairy and beef, respectively), and rifampicin (2.1% and 0% resistance among swine and dairy cattle isolates, respectively versus 14.3% resistance among beef isolates). Regardless of species, multiple drug resistance was observed most often to combinations of clindamycin and levofloxacin (n=195; 51.9%) and ampicillin, clindamycin and levofloxacin (n=41; 10.9%). The reason for the variability of resistance between animal species is unknown and requires further research.

Salmonella prevalence and antimicrobial susceptibility from the National Animal Health Monitoring System Swine 2000 and 2006 studies.

Concern about Salmonella contamination of food is compounded by fear that antimicrobials traditionally used to combat the infection will become useless due to rising antibiotic resistance. Livestock, in particular swine, often are blamed for illnesses caused by Salmonella and for increasing antibiotic resistance due to use of antibiotics in pigs. As part of the National Animal Health Monitoring System Swine 2000 and 2006 studies, swine fecal samples were cultured for Salmonella. These samples were collected from 123 operations in 17 states in 2000 and from 135 operations in 17 states in 2006. At each operation, 50 and 60 fecal samples were collected from late finisher pig pens in 2000 and 2006, respectively. Salmonella isolates were characterized to determine serogroup and serotype and were tested for susceptibility to a panel of 17 and 15 antimicrobial drugs in 2000 and 2006, respectively. A total of 5,470 and 7,788 samples were cultured for Salmonella in 2000 and 2006, respectively. Overall, 6.2% of the samples and 34.2% of the farms were positive for Salmonella in 2000. In 2006, 7.2% of the samples and 52.6% of the farms were positive. Salmonella Derby, Salmonella Typhimurium var. 5- (formerly Salmonella Typhimurium var. Copenhagen), and Salmonella Agona were the three serotypes most often recovered in both study years. The most common antimicrobial resistance pattern for Salmonella Derby in the two study years was resistance to streptomycin, sulfisoxazole, and tetracycline. Most isolates were resistant to tetracycline, sulfisoxazole, and streptomycin in both study years. The proportion of Salmonella isolates that were susceptible to all antimicrobials (pansusceptible) was 38.1% in 2000 and 20.4% in 2006. The proportion of Salmonella isolates that were resistant to three or more antimicrobials (multidrug resistant) was similar in 2000 and in 2006 (52.8 and 57.7%, respectively).

Clostridium difficile from healthy food animals: optimized isolation and prevalence.

Two isolation methods were compared for isolation of Clostridium difficile from food animal feces. The single alcohol shock method (SS) used selective enrichment in cycloserine-cefoxitin fructose broth supplemented with 0.1% sodium taurocholate, followed by alcohol shock and isolation on tryptic soy agar supplemented with 5% sheep blood, and cycloserine-cefoxitin fructose agar. The double alcohol shock method (DS) used alcohol shock prior to and after selective enrichment in cycloserine-cefoxitin fructose broth supplemented with 0.1% sodium taurocholate, followed by isolation on tryptic soy agar supplemented with 5% sheep blood and cycloserine-cefoxitin fructose agar. A total of 55 (15.9%, n = 345) swine fecal samples, 32 (2.4%, n = 1,325) dairy cattle fecal samples, and 188 (6.3%, n = 2,965) beef cattle fecal samples were positive for C. difficile by either method. However, the DS was significantly better than the SS for the recovery of C. difficile from swine feces, while the SS was significantly better than the DS for the recovery of C. difficile from beef cattle feces. There was no significant difference between methods for the recovery of C. difficile from dairy cattle feces. This study suggests that food animals might harbor C. difficile and it provides critical information that isolation methods might not have universal application across animal species.

KCl reabsorption by the lower malpighian tubule of rhodnius prolixus: inhibition by Cl(-) channel blockers and acetazolamide.

Iono- and osmoregulation by the blood-feeding hemipteran Rhodnius prolixus involves co-ordinated actions of the upper and lower Malpighian tubules. The upper tubule secretes ions (Na(+), K(+), Cl(-)) and water, whereas the lower tubule reabsorbs K(+) and Cl(-) but not water. The extent of KCl reabsorption by the lower tubule in vitro was monitored by ion-selective microelectrode measurement of Cl(-) and/or K(+) concentration in droplets of fluid secreted by Malpighian tubules isolated under oil. An earlier study proposed that K(+) reabsorption involves an omeprazole-sensitive apical K(+)/H(+) ATPase and Ba(2+)-sensitive basolateral K(+) channels. This paper examines the effects acetazolamide and of compounds that inhibit chloride channels, Cl(-)/HCO(3)(-) exchangers and Na(+)/K(+)/2Cl(-) or K(+)/Cl(-) co-transporters. The results suggest that Cl(-) reabsorption is inhibited by acetazolamide and by Cl(-) channel blockers, including diphenylamine-2-carboxylate(DPC) and 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB), but not by compounds that block Na(+)/K(+)/Cl(-) and K(+)/Cl(-) co-transporters. Measurements of transepithelial potential and basolateral membrane potential during changes in bathing saline chloride concentration indicate the presence of DPC- and NPPB-sensitive chloride channels in the basolateral membrane. A working hypothesis of ion movements during KCl reabsorption proposes that Cl(-) moves from lumen to cell through a stilbene-insensitive Cl(-)/HCO(3)(-) exchanger and then exits the cell through basolateral Cl(-) channels.