Löffler syndrome on a Louisiana pig farm

Abstract

Löffler syndrome, a fulminant eosinophilic pneumonitis associated with the larval migratory phase of human parasites, is rarely reported in the United States. A previously healthy 8-year-old male was hospitalized with tachypnea, cough, hypoxemia, and fever of one week's duration. History revealed exposure to pigs on his family's farm in southernmost Louisiana, where the patient was responsible for cleaning the farm's pigpens. His fingernails were soiled and extremely short, with the edge of the nail bed exposed secondary to onychophagia. Laboratory evaluation demonstrated peripheral eosinophilia (39%), pulmonary eosinophilia (86%), high total IgE, diffuse reticulonodular lung opacities, and mixed obstructive and restrictive pulmonary function pattern. Systemic corticosteroids were initiated for his acute respiratory insufficiency and produced rapid clinical improvement. Serum Ascaris-specific IgE was markedly elevated and he was treated with albendazole. An extensive evaluation for other infectious and allergic etiologies was negative. A site visit to the family farm and laboratory investigation was coordinated with the Louisiana Animal Disease Diagnostic Laboratory at LSU. Ascaris suum eggs were detected in fresh pig feces and in the soil immediately surrounding the pens. Ascariasis should be considered even in the absence of travel history, especially in swine raising areas that are endemic for Ascaris in pigs, such as the southeastern United States. Onychophagia is a highly probable mechanism of zoonotic fecal-oral transmission in this case, and such habits could lead to continual reinfection. Systemic corticosteroids were effective in treating the patient's acute respiratory compromise due to Löffler syndrome.

Zoonotic helminth exposure and risk of allergic diseases: A study of two generations in Norway

“…However, zoonotic exposure is not uncommon through exposure to parasites of livestock and companion animals . Indeed, a number of relatively recent studies have identified Ascaris suum infection and associated pathology (such as Loffler syndrome) to occur (albeit at low levels) in northern European and North American pig farming areas . A more common cause of zoonotic helminth infections comes from Toxocara canis and T. cati which naturally infect dogs and cats .…”

“…[14][15][16] Indeed, a number of relatively recent studies have identified Ascaris suum infection and associated pathology (such as Loffler syndrome) to occur (albeit at low levels) in northern European and North American pig farming areas. [17][18][19][20] A more common cause of zoonotic helminth infections comes from Toxocara canis and T. cati which naturally infect dogs and cats. 21 According to recent studies, levels of human exposure to these parasites can vary from 6% to 87% depending on age and local environmental factors.…”

Autochthonous Ascariasis, Mississippi, USA

“…However, highly endemic porcine ascariasis is present in some farmed pigs in the United States ( 7 ). Sporadic reports have been documented of autochthonous ascariasis cases and case clusters in northeastern states ( 8 ), and Ascaris lumbricoides roundworm–mediated Löffler syndrome (eosinophilic pneumonitis) has been reported in Louisiana over the past decade ( 9 ). Those autochthonous ascariasis cases represented spillover infections to humans from pigs.…”

“…Heavy infections may also cause malabsorption and stunting with consequent vitamin deficiencies, growth retardation, altered immunity, and impaired cognition ( 7 , 10 ). A larva migrans syndrome may be observed, caused by immune-mediated responses to the visceral migration of A. lumbricoides worm larvae through the lungs and appearing as Löffler syndrome ( 9 ).…”

“…Ascariasis is often asymptomatic or subclinical, although abdominal pain, distension, and wasting may occur (7)(8)(9)(10). Adult worms migrating in the intestinal tract may obstruct the bile or pancreatic ducts, leading to cholecystitis or pancreatitis (10).…”