Strongyloides stercoralis infection: an underlying cause of invasive bacterial infections of enteric origin. Results from a prospective cross-sectional study of a northern Italian tertiary hospital.

PURPOSE OF THE STUDY: We assessed the prevalence of S. stercoralis in a cohort of inpatients with invasive bacterial infections of enteric origin to investigate whether the parasite may facilitate these bacterial infections even in the absence of larval hyperproliferation. METHODS: We performed a prospective cross-sectional study in a hospital in northern Italy. Subjects admitted due to invasive bacterial infection of enteric origin and potential previous exposure to S. stercoralis were systematically enrolled over a period of 10 months. S. stercoralis infection was investigated with an in-house PCR on a single stool sample and with at least one serological method (in-house IFAT and/or ELISA Bordier). Univariate, bi-variate and logistic regression analyses were performed. RESULTS: Strongyloidiasis was diagnosed in 14/57 patients (24.6%; 95% confidence interval 14.1-37.8%) of which 10 were Italians (10/49, 20.4%) and 4 were migrants (4/8, 50.0%). Stool PCR was performed in 43/57 patients (75.4%) and no positive results were obtained. Strongyloidiasis was found to be significantly associated (p ≤ 0.05) with male gender, long international travels to areas at higher endemicity, deep extra-intestinal infectious localization and solid tumors. In the logistic regression model, increased risk remained for the variables deep extra-intestinal infectious localization and oncologic malignancy. CONCLUSIONS: Our findings suggest a new role of chronic strongyloidiasis in favoring invasive bacterial infections of enteric origin even in the absence of evident larval dissemination outside the intestinal lumen. Further well-designed studies should be conducted to confirm our results, and possibly establish the underlying mechanisms.

Ivermectin Plasma Concentration in Iberian Ibex (Capra pyrenaica) Following Oral Administration: A Pilot Study.

Sarcoptic mange is considered the main driver of demographic declines occurred in the last decades in Iberian ibex (Capra pyrenaica) populations. Mass treatment campaigns by administration of in-feed acaricides are used as a measure to mitigate the impact of mange in the affected populations. However, there are no data on ivermectin (IVM) pharmacokinetics in this wild caprine, and the treatment through medicated feed is not endorsed by evidence on its effectiveness. The aim of this study is to determine the pharmacokinetic profile of IVM in plasma samples of ibexes after the experimental oral administration of IVM, using high performance liquid chromatography (HPLC) with automated solid phase extraction and fluorescence detection. A dose of 500 µg of IVM per body weight was orally administered in a feed bolus to nine healthy adult ibexes (seven males and two females). Blood samples were collected by jugular venipuncture into heparin-coated tubes at day 1, 2, 3, 4, 7, 10, 15, and 45 post-administration (dpa). The highest plasma concentration of IVM (Cmax = 3.4 ng/ml) was detected 24 h after the oral administration (T1), followed by a rapid decrease during the first week post-administration. Our results reveal that plasma IVM concentration drops drastically within 5 days of ingestion, questioning the effectiveness of a single in-feed dose of this drug to control sarcoptic mange. To the best of our knowledge, this is the first study on plasma availability of oral IVM in ibexes and in any wild ungulate species.

Induction by Phenobarbital of Phase I and II Xenobiotic-Metabolizing Enzymes in Bovine Liver: An Overall Catalytic and Immunochemical Characterization.

In cattle, phenobarbital (PB) upregulates target drug-metabolizing enzyme (DME) mRNA levels. However, few data about PB's post-transcriptional effects are actually available. This work provides the first, and an almost complete, characterization of PB-dependent changes in DME catalytic activities in bovine liver using common probe substrates and confirmatory immunoblotting investigations. As expected, PB increased the total cytochrome P450 (CYP) content and the extent of metyrapone binding; moreover, an augmentation of protein amounts and related enzyme activities was observed for known PB targets such as CYP2B, 2C, and 3A, but also CYP2E1. However, contradictory results were obtained for CYP1A, while a decreased catalytic activity was observed for flavin-containing monooxygenases 1 and 3. The barbiturate had no effect on the chosen hydrolytic and conjugative DMEs. For the first time, we also measured the 26S proteasome activity, and the increase observed in PB-treated cattle would suggest this post-translational event might contribute to cattle DME regulation. Overall, this study increased the knowledge of cattle hepatic drug metabolism, and further confirmed the presence of species differences in DME expression and activity between cattle, humans, and rodents. This reinforced the need for an extensive characterization and understanding of comparative molecular mechanisms involved in expression, regulation, and function of DMEs.

Mycobacterial skin infection.

PURPOSE OF REVIEW: The aim of this article is to review the most recent evidences concerning mycobacterial skin infections, limiting the period of literature research to 2020--2021. RECENT FINDINGS: Mycobacterial skin infections include a heterogeneous group of cutaneous diseases.Cutaneous tuberculosis is usually the result of hematogenous dissemination or spread from underlying foci and it must be distinguished from tuberculids, resulting from the immunological reaction to Mycobacterium tuberculosis antigens. Leprosy prevalence was drastically reduced after introduction of multidrug therapy in the 1980 s, but cases are still reported due to underdiagnosis, and animal and environmental reservoirs. Recent advances concentrate in the diagnostic field. Specific guidelines for the treatment of nontuberculous mycobacteria skin infections are missing and surgical procedures may be required. Prognosis is better as compared to nontuberculous mycobacteria lung disease. Rapid laboratory-confirmed diagnosis of Buruli ulcer may be achieved by the IS2404 PCR. Among new drugs, telacebec is promising in terms of potency, shorter duration and tolerability in animal studies. A clinical trial in humans is planned. SUMMARY: Mycobacterial cutaneous lesions are nonpathognomonic and clinical suspicion must be confirmed by culture or molecular detection. Long-course multidrug treatment is required based on susceptibility tests. Surgical intervention may also be required. Rehabilitation and psychosocial support reduce long-term physical and mental consequences mostly in Buruli ulcer and leprosy.

Disseminated Kaposi sarcoma following COVID-19 in a 61-year-old Albanian immunocompetent man: a case report and review of the literature.

BACKGROUND: COVID-19 and its related anti-inflammatory treatment (steroids, immunomodulators) may induce the reactivation of latent bacterial, parasitic, and viral infections. According to our knowledge, no case of disseminated HHV-8-related Kaposi sarcoma (KS) after COVID-19 and its treatment has been described so far. Only one case of cutaneous KS concurrently with COVID-19 has been previously reported. CASE PRESENTATION: We describe a case of disseminated KS in a 61-year-old immunocompetent Albanian man after hospitalization for COVID-19. METHODS FOR LITERATURE RESEARCH: We used PubMed as biomedical database for the literature research. We selected keyword combinations including "Kaposi sarcoma," "HHV-8," "immunocompetent," "COVID-19," "SARS-CoV-2," and "steroids." No time or language limitation was set. Titles and abstracts of selected articles were systematically screened. Articles were included in the examination if they were published under free access through the digital library of the University of Brescia (Italy), and provided full text. Articles were excluded if the topic was beyond the aim of our study. Finally, we selected 15 articles. RESULTS: We describe a case of KS in COVID-19 patient and postulate that Interleukin-6 (IL-6) activity and steroid-induced immunodeficiency may play a major role in KS emergence. No published case of disseminated KS following COVID-19 in otherwise healthy individuals was found through the systematic literature review, despite the high incidence of COVID-19 in areas with medium-high prevalence of HHV-8 infection. This observation might be explained by the role of individual genetic susceptibility factors. CONCLUSIONS: SARS-CoV-2 infection and its treatment may lead to reactivation of several latent infections, including HHV-8 and its related clinical syndrome, Kaposi sarcoma.

Effects of Compost-Bedded Pack Barn on Circulating Cortisol and Beta-Endorphins in Dairy Cows: A Case Study.

The up-to-date literature suggests that the compost-bedded pack barn housing system is capable of remarkably improving productive and reproductive performance, as well as health status and welfare, in dairy cattle. However, there is currently limited knowledge available on the endocrine and biochemical changes in animals housed in such alternative systems. Therefore, this study aimed to measure blood cortisol (COR) and beta-endorphins (BE) in 22 two-year-old primiparae Fleckvieh cows, who were randomly allotted to the following two different housing systems: CB (n = 11) and FB (n = 11). Blood samples were collected at the beginning of the experiment (T0) and every two months thereafter (T1, T2, and T3). The COR and BE were measured through an immunoenzymatic kit. With the only exception being T0, no differences were observed over time between the two groups, neither for COR nor for BE. However, the blood cortisol levels of the CB cows decreased over time, while a T1 peak was identified in the FB group. On the contrary, both the housing systems displayed numerically higher BE at T3 than at the other experimental times. Therefore, the overall data suggest that the compost-bedded pack barn did not significantly affect the studied parameters. Accordingly, cow welfare should be assessed using a wider panel of animal-based indicators.

Pulmonary nontuberculous mycobacterial infections and environmental factors: A review of the literature.

BACKGROUND: Pulmonary nontuberculous mycobacterial (pNTM) infection is mainly acquired through the inhalation of bioaerosols. Nevertheless, behavioural restrictions are rarely given by clinicians to susceptible populations, in part because the available guidelines for pNTM management emphasize more diagnosis and treatment than prevention. Aim of this review is to clarify if pNTM prevention should routinely include recommendations about risk reducing behaviors. METHODS: We used PubMed as biomedical database. We limited our search to the publication period 2000 to 2020 with selected keyword combinations including "nontuberculous mycobacteria", "water", "soil", and "exposure". Titles and abstract of selected articles were systematically screened. Articles were included in the analysis if they were published under free access through the digital library of the University of Brescia (Italy), and provided full text either in English, French, German or Italian. Articles were excluded if the topic was beyond the aim of our study. Finally, we selected 20 articles. RESULTS: Studies disagree in identifying the type of aerosol posing the highest risk for the development of pNTM infection. In the retrieved publications the colonization of household niches has been associated with a higher risk of pNTM disease, such as in the exposure to shower aerosols. Considering the non-household settings, the exposure to aerosols in indoor swimming and the higher soil exposure (>2 h/week) seem to correlate with a higher risk to develop pNTM disease. According to our findings, randomized behavioural intervention studies are missing. CONCLUSIONS: Stringent scientific evidence is missing to formulate recommendations on behavioural risk reduction for pNTM.

Decrease in new diagnosis of HIV/AIDS in the two years period 2019-2020: impact of COVID-19 pandemic.

The emergence SARS-CoV-2 in late 2019 and early 2020 has caused a pandemic of unprecedented proportions. Management of COVID-19 became emergent public health priorities, and the impact on other public health initiatives, such as expanded HIV screening and linkage to care, remain largely unknown. In this Single-Center retrospective observational study, we describe the characteristics and circumstance of the new HIV cases during 2020 compared to 2019. We observed a decrease of HIV diagnosis during this period. Interestingly, median age at HIV diagnosis decreased of one decade and percentage of female patients was higher. In addition, more patients received diagnosis during hospitalization and more AIDS-defining conditions, such as Pneumocystis pneumonia, were detected. We express our concern that HIV new diagnoses will increase as a result of people's inability to get tested or treated in this period. More efforts are needed to improve local screening programs both during and after COVID-19 pandemic.

Impact of COVID-19 pandemic on HIV viremia: a single-center cohort study in northern Italy.

BACKGROUND: Brescia Province, northern Italy, was one of the worst epicenters of the COVID-19 pandemic. The division of infectious diseases of ASST (Azienda Socio Sanitaria Territoriale) Spedali Civili Hospital of Brescia had to face a great number of inpatients with severe COVID-19 infection and to ensure the continuum of care for almost 4000 outpatients with HIV infection actively followed by us. In a recent manuscript we described the impact of the pandemic on continuum of care in our HIV cohort expressed as number of missed visits, number of new HIV diagnosis, drop in ART (antiretroviral therapy) dispensation and number of hospitalized HIV patients due to SARS-CoV-2 infection. In this short communication, we completed the previous article with data of HIV plasmatic viremia of the same cohort before and during pandemic. METHODS: We considered all HIV-patients in stable ART for at least 6 months and with at least 1 available HIV viremia in the time window March 01-November 30, 2019, and another group of HIV patients with the same two requisites but in different time windows of the COVID-19 period (March 01-May 31, 2020, and June 01-November 30, 2020). For patients with positive viremia (PV) during COVID-19 period, we reported also the values of viral load (VL) just before and after PV. RESULTS: the percentage of patients with PV during COVID-19 period was lower than the previous year (2.8% vs 7%). Only 1% of our outpatients surely suffered from pandemic in term of loss of previous viral suppression. CONCLUSIONS: Our efforts to limit the impact of pandemic on our HIV outpatients were effective to ensure HIV continuum of care.

Emergency department admission and hospitalization for COPD exacerbation and particulate matter short-term exposure in Brescia, a highly polluted town in northern Italy.

BACKGROUND: Short-term exposure to high Particulate Matter (PM) concentrations worsens several respiratory conditions. OBJECTIVES: We evaluated the relationship between short-term exposure to Particulate Matter and fine Particulate Matter (PM10 - PM2.5) and Emergency Department (ED) admissions and hospitalizations for COPD exacerbation observed at the University Hospital, Spedali Civili of Brescia, a city with some of the highest yearly levels of air pollution in Italy. METHODS: We collected data from patients admitted to the ED with a COPD exacerbation diagnosis, starting from January 2014 to January 2016. Daily PM levels were collected from the Environmental Protection Regional Agency (ARPA). We performed a time-series analysis using the Poisson regression model with single and multiple day-lag. Results were expressed as Relative Risk (RR) and Excess of Relative Risk (ER) for COPD exacerbation-related ED admissions and hospitalizations, over a 10µg/m3 increase in PM concentration. RESULTS: We collected data from 431 COPD patients. Both PM10 and PM2.5 were significantly associated with the risk of COPD exacerbation-related ED admission and hospitalization. Each increase of 10µg/m3 of PM10 and PM2.5 corresponded respectively to a RR for ED admissions of 1.06 and 1.08 at lag0-1; 1.06 and 1.09 at lag0-5 (p < 0.05). Similar results for COPD Exacerbation-related hospitalizations were found, with a RR of 1.07 and 1.10 at lag0-1 and 1.07 and 1.11 at lag0-5 for each increase of 10µg/m3 PM10 and PM2.5, respectively. CONCLUSIONS: Our findings show that in a highly polluted city of Northern Italy, short-term increase in exposure to PM10-PM2.5 is associated with a higher risk of ED admission and hospitalization due to COPD exacerbation with a greater incidence during the winter season.

Behavioral Therapy and Fluoxetine Treatment in Aggressive Dogs: A Case Study.

Canine aggression is a major concern, affecting millions of people worldwide, and treatment can be challenging even for skilled veterinarians. Empiric use of fluoxetine is sometimes attempted, although few data regarding long-term effects in aggressive dogs are available. The aim of the study was to investigate clinical effectiveness of fluoxetine (1.5 mg/kg/die PO) combined with a behavior modification program for treatment of canine dominance-related aggression. Circulating levels of fluoxetine, norfluoxetine, and serotonin (5-HT) were also measured. Eight dogs with a diagnosis of dominance aggression (owner-directed) were enrolled. Before treatment (T0), and after one (T1), two (T2), four (T3), and six (T4) months of fluoxetine administration, clinical outcomes were graded using a five-point frequency scale (0-4), and blood samples were collected to measure fluoxetine/norfluoxetine (high-performance liquid chromatography) and 5-HT (ELISA) levels. Following treatment, a decrease in behavioral test scores was observed at T1-T4. Increasing concentrations of circulating fluoxetine and norfluoxetine were measured throughout the follow-up. Correlation between norfluoxetine levels and clinical scores was observed at T4. Starting from T1, a significant decrease in 5-HT levels was observed. Our data suggest that fluoxetine (1.5 mg/kg/day) when associated with behavior treatment is effective in controlling canine aggression over a six-month period, and that, in dogs norfluoxetine levels seem reliable in predicting clinical efficacy.

Abacavir adverse reactions related with HLA-B*57: 01 haplotype in a large cohort of patients infected with HIV.

OBJECTIVE: Carriage of human leukocyte antigen (HLA)-B*57:01 allele increases the risk of abacavir hypersensitivity reaction. Therefore, since 2008 HIV treatment guidelines recommend HLA-B*57:01 screening before abacavir administration, greatly reducing hypersensitivity reaction rate. However, clinically suspected abacavir-related hypersensitivity reactions are described in allele non-carriers. Major aim of this study was to evaluate the relationship between HLA-B*57:01 pattern and abacavir-related hypersensitivity reaction, focusing on hypersensitivity reaction prevalence in allele non-carriers. METHODS: We included all outpatients aged >18 years old with HIV infection and known HLA-B*57:01 pattern, followed at our Department from January 2000 until December 2017. Patients were divided according to HLA-B*57:01 pattern and first antiretroviral treatment prescribed (containing or not abacavir) as follows: HLA-B*57:01 allele carriers treated with abacavir and HLA-B*57:01 allele non-carriers treated with abacavir. We considered all adverse events reported during first abacavir administration, differentiating between confirmed hypersensitivity reactions and non-hypersensitivity reactions, according to abacavir hypersensitivity reaction definition included in the abacavir EU Summary of Product Characteristics and the US Prescribing Information. RESULTS: A total of 3144 patients had a known HLA-B*57:01 pattern. About 5.4% of them showed allele polymorphism; Caucasian ethnicity was the most represented. In this cohort, 1801 patients were treated with a first abacavir-containing regimen (98.2% of them was represented by allele non-carriers). 191 out of 1801 patients discontinued abacavir because of toxicity/intolerance; among them 107 described adverse events fulfilled the criteria of confirmed abacavir hypersensitivity reaction (22/32 allele-positive patients and 85/1769 allele-negative patients). After having experienced a confirmed abacavir hypersensitivity reaction, abacavir was re-administered to eight HLA-B*57:01 negative patients. Seven of them re-experienced a syndrome consistent with hypersensitivity reaction, finally leading to drug discontinuation. Overall, no fatal reactions were described. CONCLUSION: Not all abacavir-related side effects occur as a result of classic HLA-B*57:01-mediated hypersensitivity reaction, as they can develop irrespective of HLA-B*57:01 status. Clinical vigilance must be an essential part of the management of individuals starting abacavir, at any time during treatment. In a 'real-life' setting, clinical diagnosis of suspected abacavir hypersensitivity reaction in allele non-carriers remains crucial for further clinical decision making.

Parasitic skin infections: neglected diseases or just challenging for diagnosis?

PURPOSE OF REVIEW: The aim of the article is to review the most recent evidence concerning parasitic skin infections. RECENT FINDINGS: Parasitic skin infections are increasingly reported worldwide. Special at-risk categories are migrants, returning travelers, and immunocompromised individuals, who are at higher risk to present disseminated disease. The number of reported cases is growing even outside the endemic areas as a consequence of international travels, migration flows, increasing immunocompromised population, climate change, and natural disasters. SUMMARY: Skin parasitoses are neglected infections. Funding assigned to prevent and treat them is limited, even if they affect millions of persons worldwide. Diagnosis could be a challenge for clinicians of high-income countries who are facing an increasing number of such infections related to great epidemiological events.

Non-typhoidal Salmonella aortitis.

Non-typhoidal Salmonella (NTS) spp. causes about 40% of all infective aortitis and it is characterized by high morbidity and mortality. Human infection occurs by fecal-oral transmission through ingestion of contaminated food, milk, or water (inter-human or zoonotic transmission). Approximately 5% of patients with NTS gastroenteritis develop bacteremia and the incidence of extra-intestinal focal infection in NTS bacteremia is about 40%. The organism can reach an extra-intestinal focus through blood dissemination, direct extension from the surrounding organs and direct bacterial inoculation (e.g. invasive medical procedures). Medical and surgical interventions are both needed to successfully control the infection. Here, we report a case of abdominal sub-renal aortitis caused by Salmonella enterica serovar Enteritidis in an 80-year-old man.

Open-label clinical trial of rectally administered levetiracetam as supplemental treatment in dogs with cluster seizures.

BACKGROUND: Treatment options for at-home management of cluster seizures (CS) and status epilepticus (SE) are limited. The pharmacokinetics of levetiracetam (LEV) after rectal administration in both healthy and epileptic dogs has been investigated recently. HYPOTHESIS/OBJECTIVES: To investigate the clinical efficacy of rectally administered LEV in preventing additional seizures in dogs presented for CS and SE. We hypothesized that rectal administration of LEV in addition to a standard treatment protocol would provide better control of seizure activity as compared with the standard treatment protocol alone. ANIMALS: Fifty-seven client-owned dogs with CS or SE. METHODS: Prospective open-label clinical trial. Patients included in the study were assigned to receive either a standard treatment protocol comprising IV/rectal diazepam and IV phenobarbital q8h (control group) or a standard treatment protocol in association with a single dose of 40 mg/kg LEV rectally (rectal LEV group). Dogs that experienced no additional seizures were defined as responders, whereas those that showed additional seizure activity were classified as nonresponders. RESULTS: Twenty-one dogs were assigned to the rectal LEV group, and 36 to control group. Given the small number of cases of SE, statistical analysis was performed only on patients with CS. The response rate was 94% in the rectal LEV group and 48% in the control group (P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: Rectally administered LEV combined with a standard treatment protocol provided good control of seizure activity in patients with CS. The validity of these results should be confirmed in a double-blinded, placebo-controlled clinical trial.

Correction to: Acute epididymo-orchitis due to Salmonella Typhi in a young man from Bangladesh.

The original version of this article unfortunately contained a mistake. Arnaldo Caruso was not listed among the authors.

Acute epididymo-orchitis due to Salmonella Typhi in a young man from Bangladesh.

S. typhi infection rarely involves the genitourinary system. We report the first described case of acute epididymo-orchitis due to S. typhi in a 14-year-old boy from Bangladesh. A high index of suspicion should be maintained when evaluating patients coming from endemic countries also in case of unusual sites of infection.

Pharmacokinetics of rectal levetiracetam as add-on treatment in dogs affected by cluster seizures or status epilepticus.

BACKGROUND: Levetiracetam can be used for seizure control alone or in combination with other antiepileptic medications. A previous study achieved the minimum targeted serum drug concentration after rectal administration of levetiracetam in healthy dogs. The purpose of the present study was to determine the pharmacokinetics of rectal LEV in dogs presented for cluster seizures or status epilepticus and potentially in treatment with other anti-epileptic drugs. Furthermore, preliminary information on response to this treatment as add-on to the standard treatment protocol is reported. RESULTS: Eight client-owned dogs were enrolled. Plasma levetiracetam concentrations (measured at 0, 30, 60, 90, 120, 180, 240, 360, 720, and 1440 min after drug administration) reached the minimum target concentration (5 µg/ml) at 30 min in all but one patient. At T1 (30 min) the mean concentration was 28.2 ± 15.5 µg/ml. Plasma concentrations remained above the targeted minimum concentration in all patients until 240 min and in 7/8 until 360 min. Six out of eight patients experienced no seizures in the 24-h period after hospitalization and were classified as "responders". CONCLUSIONS: Minimum plasma levetiracetam concentration can be reached after rectal administration of 40 mg/kg in dogs affected by cluster seizures and status epilepticus and concurrently receiving other antiepileptic drugs. These preliminary results may encourage the evaluation of rectal levetiracetam as an additional treatment option for cluster seizures and status epilepticus in a larger number of dogs.

Set-up of a multivariate approach based on serum biomarkers as an alternative strategy for the screening evaluation of the potential abuse of growth promoters in veal calves.

A chemometric class modelling strategy (unequal dispersed classes - UNEQ) was applied for the first time as a possible screening method to monitor the abuse of growth promoters in veal calves. Five serum biomarkers, known to reflect the exposure to classes of compounds illegally used as growth promoters, were determined from 50 untreated animals in order to design a model of controls, representing veal calves reared under good, safe and highly standardised breeding conditions. The class modelling was applied to 421 commercially bred veal calves to separate them into 'compliant' and 'non-compliant' with respect to the modelled controls. Part of the non-compliant animals underwent further histological and chemical examinations to confirm the presence of either alterations in target tissues or traces of illegal substances commonly administered for growth-promoting purposes. Overall, the congruence between the histological or chemical methods and the UNEQ non-compliant outcomes was approximately 58%, likely underestimated due to the blindness nature of this examination. Further research is needed to confirm the validity of the UNEQ model in terms of sensitivity in recognising untreated animals as compliant to the controls, and specificity in revealing deviations from ideal breeding conditions, for example due to the abuse of growth promoters.

Study of dexamethasone urinary excretion profile in cattle by LC-MS/MS: comparison between therapeutic and growth-promoting administration.

Dexamethasone is a potent synthetic corticosteroid widely employed as a therapeutic agent in cattle. Besides this legal use, corticosteroids are also administered at low dosages as growth-promoters either alone or in combination with other steroids or with beta-agonists. For this reason, appropriate control plans are established to survey corticosteroid misuse, using liver or urine as biological matrices. Since few data are available about the kinetics of dexamethasone excretion in meat cattle, an experimental study was designed to assess the drug residue levels in urines following either a therapeutic (60 microg of dexamethasone sodium phosphate/kg b.w., for three consecutive days) or a growth-promoting schedule (0.7 or 1.4 mg of dexamethasone sodium phosphate per capita/day for 60 days). The urinary elimination of dexamethasone, which was predominantly excreted in the unmodified form, was determined by high-performance liquid chromatography/tandem mass spectrometry at different time intervals, i.e. during the treatments and after appropriate withdrawal times. Our findings confirm the high and rapid rate of dexamethasone urinary excretion irrespective of the nature of the treatment, and provide useful reference values that can be conveniently employed for forensic purposes.