Clostridium septicum infection complicating Hemolytic-Uremic Syndrome: a case report and review of the literature.

Clostridium septicum (C. septicum) is a zoonotic bacillus found in 2.8% of healthy human stools. In humans, it can cause serious infections such as bacteremia, myonecrosis, and encephalitis by spreading through the bloodstream. Reports of Shiga toxin-producing Escherichia Coli-related hemolytic-uremic syndrome complicated by C. septicum superinfection are rare, likely because colonic microangiopathic lesions by Shiga toxin-producing Escherichia Coli facilitate bacterial dissemination. Only 13 cases of Shiga toxin-producing Escherichia Coli-related hemolytic-uremic syndrome with C. septicum superinfection have been reported to date, according to our litterature review, with a 50% mortality rate. The lack of clinico-laboratory clues suggesting this condition makes the diagnosis challenging. For these reasons C. septicum superinfection usually goes undiagnosed in patients with Shiga toxin-producing Escherichia Coli-related hemolytic-uremic syndrome, and results in unfavorable outcomes. In this paper, we describe the case of a 5-year-old girl admitted for Shiga toxin-producing Escherichia Coli-related hemolytic-uremic syndrome who developed C. septicum coinfection leading to a fatal outcome. We carried out a review of the available literature on C. septicum infection complicating Shiga toxin-producing Escherichia Coli-related hemolytic-uremic syndrome and we compared the clinical features of the observed cases with those of an historical cohort of uncomplicated Shiga toxin-producing Escherichia Coli-related hemolytic-uremic syndrome. The mechanisms of superinfection are still unclear and clinical features are indistinguishable from those of uncomplicated Shiga toxin-producing Escherichia Coli-related hemolytic-uremic syndrome. However, rapid deterioration of clinical conditions and evidence of neurological involvement, associated with abnormal radiological findings, require immediate management. Although therapeutic approaches have not been directly compared, neurosurgical treatment of amenable lesions may improve the clinical outcome of patients with C. septicum-hemolytic-uremic syndrome.

Hyponatremia in infants with community-acquired infections on hospital admission.

Acute moderate to severe gastroenteritis is traditionally associated with hypernatremia but recent observations suggest that hypernatremia is currently less common than hyponatremia. The latter has sometimes been documented also in children with acute community-acquired diseases, such as bronchiolitis and pyelonephritis. We investigated the prevalence of dysnatremia in children with acute moderate severe gastroenteritis, bronchiolitis and pyelonephritis. This prospective observational study included 400 consecutive previously healthy infants ≥4 weeks to ≤24 months of age (232 males and 168 females): 160 with gastroenteritis and relevant dehydration, 160 with moderate-severe bronchiolitis and 80 with pyelonephritis admitted to our emergency department between 2009 and 2017. Circulating sodium was determined by means of direct potentiometry. For analysis, the Kruskal-Wallis test and the Fisher's exact test were used. Hyponatremia was found in 214 of the 400 patients. It was common in gastroenteritis (43%) and significantly more frequent in bronchiolitis (57%) and pyelonephritis (68%). Patients with hyponatremia were significantly younger than those without hyponatremia (3.9 [1.6-13] versus 7.5 [3.4-14] months). The gender ratio was similar in children with and without hyponatremia. Hyponatremia was associated with further metabolic abnormalities (hypokalemia, hyperkalemia, metabolic acidosis or metabolic alkalosis) in gastroenteritis (71%) and pyelonephritis (54%), and always isolated in bronchiolitis. In conclusion, hyponatremia is common at presentation among previously healthy infants with gastroenteritis, bronchiolitis or pyelonephritis. These data have relevant consequences for the nutrition and rehydration management in these conditions.