Nematodes

Gut nematodes:

• Hookworms (Necator americanus, Ancylostoma duodenale)
• Whipworm (Trichuris trichuria)
• Ascaris lumbricoides
• Strongyloides stercoralis
• Trichinella spiralis
• Enterobius vermicularis

AGE PREVALENCE/INTENSITY

• Prevalent in poor communities
• Ascaris and Trichuris peaks in children (poor hygiene?)
• Hookworm/Stronglyoides increase up to adulthood
• High risk groups:
  • Children (preschool and school age)
    • highest intensities Trichuris, Ascaris
    • suffer from hookworm anaemia.
    • developing children benefit most from treatment in terms of physical and mental development
  • Girls and women
    • highest intensity of infection with hookworm
    • pregnancy, lactation, menstruation puts pressure on Fe reserves
    • highest prevalence of hookworm anaemia

Treatment: WHO recommends mass drug administration

• where? community prevalence of Ascaris, Trichuris and/or hookworm is >50% (or lower if resources allow)

• how? safe, single-dose, cheap Mebendazole or Albendazole* administered by teachers (* Levamisole and Pyrantel are also on the WHO list of essential drugs), treatment of schoolchildren ensures good compliance
• how often? Prevalence: >50% – 2x/year; >20<50% – 1x/year

Microfilarial (vector-transmitted)

• Wucheria bancrofti
• Brugia malayi
• Loa loa