Hookworm disease
dr hadeel fadhil FIBMS
A common chronic parasitic infection with a variety of symptoms ,usually in proportion to the degree of anemia .
In a heavy infections , the bloodletting activity of the nematode lead to iron deficiency & hypochromic, microcytic anemia, the major cause of disability.
Children with heavy , long term infection may have hypoproteinemia and may be related in mental and physical development .
Occasionally, sever acute pulmonary and GI reaction follow exposure to infective larvae.
Death is infrequent and usually can be attributed to other infection .
Light hookworm infections generally produce few or no clinical effects .
Infection is confirmed by finding hookworm eggs in feces , stool examination may be negative early in the course of infection until the worm mature
Infectious agent
Necator americanus
Ancylostoma duodenale
Mode of transmission :
Eggs in feces are deposited on the ground and hatch under favorable conditions of moisture , temperature & soil type , larvae develop , becoming infective in 7-10 days .
Human infection occurs when the infective larvae penetrate the skin , usually in the foot , in so doing , they produce a characteristic dermatitis .
The larvae of Nector& other Ancylostoma normally enter the skin and pass via lymphatic & blood stream to the lungs, enter the alveoli , migrate up the trachea to the pharynx, are swallowed and reach the small intestine where they attach to the intestinal wall , develop to maturity in 6-7 weeks and typically produced thousands of eggs per day .
Symptoms may develop after a few weeks to many months , depending on intensity of infection and iron intake of the host.
Period of communicability :
Not transmitted from person to person, but infected people can contaminate soil for several years in the absence of treatment .
Under favorable conditions , larvae remain infective in soil for several weeks .
Susceptibility and resistance : universal , there is no evidence that immunity develops with infection .
Methods of control
A- preventive measures :
1- educate the public to the dangers of soil contamination by human , cat or dog feces , and in preventive measures , including wearing shoes in endemic areas.
2- prevent soil contamination by installation of sanitary disposal systems for human feces.
3- examine and treat people migrating from endemic to receptive nonendemic areas .
B- control of patient , contact & immediate environment :concurrent disinfection : sanitary disposal of feces to prevent contamination of soil .
Quarantin : none
Immunization of contact : none
Investigation of contacts & source of infection : each infected contact and carrier is a potential or actual indirect spreader of infection.
Specific rx : single dose rx with mebendazol, albendazol , levamisole is recommended.
Iron supplementation will correct the anemia with worm therapy.