**1.2. Specific defense mechanisms**

Adaptive immunity relays on the interaction between antigen-presenting cells (macrophag‐ es, dendritic cells, neutrophils) with specific T-lymphocytes in the context of cell mediated immunity, as well as, on the antibodies production by activated B-lymphocytes (humoral immunity) (Kohlmeter JE, Woodland DL, 2006).

Mode of contamination

Pathophysiology

Diagnosis

served.

Laboratory findings

tacharya T, 2001).

Treatment

(Santra A, 2001) described.

after ingestion (Sarinas PS, Chitkara RK, 1997).

intestine can occur, caused by adult worms.

The starting point is the survival of eggs able to contaminate ingesta by the new host. Poor sanitation, fecal contamination of food or water, are the main risk factors of dissemination. Embryonated eggs (2-4 weeks), when ingested are dissolved in the stomach juice and then release rabdoid larvae in the duodenum, before migration through the intestine. Larvae then enter the portal system via capillaries and lymphatics, after penetrating the wall of the intes‐ tine. The involvement of the hepatic circulation allow the right heart and lung invasion. The eggs reach the alveolar space after crossing the capillary walls and can be swallowed and then reach again the small intestine to mute in adult forms. This pilgrimage can take 14 days

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http://dx.doi.org/10.5772/52371

Adult worms or migrating larvae exert a mechanical pressure on lung structures inducing inflammatory responses, leading to granuloma formation with eosinophils, neutrophils and macrophages. Activated cells release cytokines such as IL-3 and IL-5 involved in the recruit‐ ment and differenciation of eosinophils, explaining the blood and tissue eosinophilia report‐ ed. TH2 Lymphocytes are responsible for the high IgE (Yazicioglia, 1996) and IgG4 levels

Hypersensitivity reaction inducing peribronchial inflammation, mucus production, and

Abdominal manifestations are currently reported: gastric pain, vomiting, diarrhea, abdomi‐ nal discomfort. In some complicated cases pancreatitis or obstruction of biliary duct or small

Respiratory symptoms due to larval migration in the lungs, consist in mild cough or Loef‐ fler's syndrome (Ford RM, 1996). This syndrome associates respiratory symptoms (dry cough, wheezing, dyspnoea) with blood and lung eosinophilia, and chest radiograph with fleeting infiltrates. General symptoms such as fever, loss of appetite, myalgia can be ob‐

Serological approach (specific IgG4 antibodies) could be helpful (Santra A *et al*., 2001; Bhat‐

sometimes bronchospasm is responsible for the clinical manifestations.

Pneumonia is a more rare condition with ascariasis infection

Stool examination may show eggs or adult worms.

Blood hypereosinophilia and high IgE level are common.

Chest radiograph may show migrating inhomogenous alveolar infiltrates.

Larvae may be found in respiratory secretions
