Pulmonary manifestations of schistosomiasis

Bilharziosis or schistosomiasis is the third leading endemic parasitic disease in the world, following malaria and ambiasis. More than 300 million individuals are infested. Schistomosomes are blood flukes which live in the perivisceral veins. Clinical signs result from ova migrations. Transmitted by urine and feces, the parasite cycle requires intermediary host, usually fresh water snails. Bilharsiosis is endemic in tropical zones where it is a major public health problem closely correlated with the socio-economic conditions. Liver, intestinal or urinary complications, depending on the species, lead to underestimated morbidity and mortality. Pulmonary lesions are attributed to 3 species: S. haematobium, S. mansoni and S. japonicum. Although the lung is mandatory step in the parasite cycle, pulmonary manifestations are limited. They can be acute or chronic depending on the phase of the cycle, but are the most frequent extradigestive localization for S. mansoni. Morbidity due to chronic manifestations is particularly severe and should be prevented whenever possible.