Muellerius

  • Common, although not major pathogens; little economic importance.

Life-Cycles

    • Indirect life-cycle involving mollusc intermediate hosts
    • L1 passed in faeces, penetrate foot of mollusc, develop to L3 in 2-3 weeks
    • Infected mollusc ingested with grass
    • L3 released by digestion and travel to lungs by lymphatic route
    • Adults found in alveoli/parenchyma (Muellerius) or small bronchioles (Protostrongylus)
    • Prepatent period 6-10 weeks (Muellerius), 5-6 weeks (Protostrongylus)

Epidemiology

    • High prevalence because of wide range of intermediate hosts, prolonged survival of larvae in faeces, long periods of patency (>2 years) and poor host immunity