Thyrotoxicosis outbreak linked to consumption of minced beef and chorizo: Minas, Uruguay, 2003–2004

Clinical characteristics and outcomes of an exogenous thyrotoxicosis epidemic in prison

Introduction

An outbreak of exogenous thyrotoxicosis is an uncommon cause of thyrotoxicosis. This study aimed to investigate the characteristics and outcomes of exogenous thyrotoxicosis and electrolyte imbalance in a prison during an outbreak of exogenous thyrotoxicosis in the Phitsanulok, Thailand prison.

Methods

This study collected cross-sectional data during an outbreak of thyrotoxicosis among inmates at Phitsanulok prison between 29 December 2019 and 17 January 2020. In the first phase, a total of 2815 prisoners were screened for thyroid-stimulating hormone (TSH), potassium levels and pulse rate. In the second phase, samples from 490 male prisoners were collected for test on thyroid function, serum electrolytes and urine electrolytes. Thyroglobulin levels were also measured in patients with thyrotoxicosis. A questionnaire was used to obtain patient information about signs and symptoms of thyrotoxicosis.

Results

The prevalence of subclinical thyrotoxicosis was 78.1%. The pulse rate was significantly higher in the subclinical thyrotoxicosis group. Weight loss, palpitation, muscle weakness and fatigue were found predominantly in the subclinical thyrotoxicosis group. The prevalence of hypokalaemia was 38.4%; however, there was no difference between subclinical thyrotoxicosis and normal TSH. The mean magnesium levels were significantly lower in the subclinical thyrotoxicosis group. Patients with hypokalaemia mainly showed potassium loss through the kidneys. Almost all patients with suppressed TSH levels had low to normal thyroglobulin levels. In addition, the mean of calculated total step-up deiodinase activity in patients with subclinical thyrotoxicosis was lower than 30 nmol/s, which was an additional clue to confirm exogenous thyrotoxicosis. The frozen meat during the outbreak had higher levels of thyroid hormone compared with the control group.

Conclusions

With an outbreak of thyrotoxicosis, most likely due to exposure to exogenous thyroid hormone in frozen meat, our findings have raised awareness of nutritional problems in prison. The development of surveillance systems to prevent outbreaks is urgently needed.

Dietary hyperthyroidism in dogs

OBJECTIVES

Evaluation of dogs with elevated plasma thyroxine concentration fed raw food before and after changing the diet.

METHOD

Between 2006 and 2011 all dogs presented with an elevated plasma thyroxine concentration and a dietary history of feeding raw food were included. Thyroxine (reference interval: 19·3 to 51·5 nmol/L) and in many cases also thyroid-stimulating hormone concentrations (reference interval: <0·30 ng/mL) were measured initially and after changing the diet.

RESULTS

Twelve dogs were presented with a median age of five years. The median plasma thyroxine concentration was 156·1 (range of 79·7 to 391·9) nmol/L; in six dogs, thyroid-stimulating hormone concentration was measured and was <0·03 ng/mL in five dogs and 0·05 ng/mL in one dog. Six dogs showed clinical signs such as weight loss, aggressiveness, tachycardia, panting and restlessness while six dogs had no clinical signs. After changing the diet eight dogs were examined: thyroxine concentration normalised in all dogs and clinical signs resolved.

CLINICAL SIGNIFICANCE

Dietary hyperthyroidism can be seen in dogs on a raw meat diet or fed fresh or dried gullets. Increased plasma thyroxine concentration in a dog, either with or without signs of hyperthyroidism, should prompt the veterinarian to obtain a thorough dietary history.

Intermittent and recurrent episodes of subclinical hypothyroidism, central hypothyroidism and T3-toxicosis in an elderly woman

Exogenous thyrotoxicosis is usually caused by ingestion of excessive amounts of thyroid hormone, which could be intentional or surreptitious (known as factitious thyrotoxicosis). Non-pharmacological exogenous thyrotoxicosis is an exceptional event. One example is alimentary thyrotoxicosis, which is caused by the ingestion of meat or sausage containing thyroid tissue, inadvertently mixed with traces of muscles and other tissues of the animal's neck (hamburger thyrotoxicosis). We report for the first time a patient who had recurrent episodes of triiodothyronine (T3) toxicosis for several years due to inadvertent chronic consumption of contaminated traditional Spanish cold meat with porcine thyroid.