1. Ancylostomiasis & Necatoriasis
Nematode Diseases
Ancylostomiasis & Necatoriasis
Trichostrongyliasis
Dr. A. Farahnak
*Dept. of Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran

2. SCOPE OF PARASITOLOGY AND MYCOLOGY COURSE
Helminthes and Helminth Diseases
Trematodes and Trematod Diseases: Schistosomes, Fasciola and others
Cestodes and Cestod diseases: Taenia , Hydatid cyst and others
Nematodes and Nematod diseases: Ascaris, Ancylostomes and others
Protozoa and Protozoa Diseases
Fungi and Fungi Diseases
Arthropods and Arthropoda Diseases

3. Introduction on Nematod Diseases
Size: mm (Stongyloides, Trichostrongyloides,.. – cm (Ascaris, Dracunculus,..)
Shape: Round worm
Distribution: World wide (Filaria worm)
Transmission mode: Direct (oxyuris), Food (Trichinella,..),Insect (Filaria worm)
Pathogenesis: Mostly Intestinal
Diagnosis: Egg (stool), Larva (blood, stool)
Treatment: Mebendazole,..
Prevention and control: Food sanitation, Insect control, ..

4. content Ancylostomiasis / Necatoriasis / Cutaneuos Larva Migrance
Trichostrongyliasis

5. Hook worm diseases (Ancylostomiasis& Necatoriasis)
Causal Agents: The human hookworms include two nematode (roundworm) species, Ancylostoma duodenale and Necator americanus.  (Adult females: 10 to 13 mm (A. duodenale), 9 to 11 mm (N. americanus); adult males: 8 to 11 mm (A. duodenale), 7 to 9 mm (N. americanus). 

6. Rhabditiform larva (L1)
Filariform larva (L3)

7. Geographic Distribution:
The second most common human helminthic infection (after ascariasis). 
Worldwide distribution, mostly in areas with moist, warm climate. 
Both N. americanus and A. duodenale are found in Africa, Asia and the Americas. 
Necator americanus predominates in the Americas and Australia, while only
A. duodenale is found in the Middle East, North Africa and southern Europe.

8. Life Cycle :49-56 from larva to adult
A. duodenale: Mouth > Skin
N. americanus: Skin > Mouth
A. duodenale 0.15 ml
N.americanus 0.05 ml
A.d: 10,000-25,000
N.a: 5,000-10,000

9. Pathogenesis &Clinical Features: Iron deficiency anemia (caused by blood loss (0.03 in N.americanus and in A.duodenale) at the site of intestinal attachment of the adult worms) is the most common symptom of hookworm infection, and can be accompanied by cardiac complications.  Gastrointestinal and nutritional/metabolic symptoms can also occur.  In addition, local skin manifestations ("ground itch") can occur during penetration by the filariform (L3) larvae, and respiratory symptoms can be observed during pulmonary migration of the larvae. interesting consequence in the case of Ancylostoma duodenale infection is translactational transmission of infection.

10. Laboratory Diagnosis:
Microscopic identification of eggs in the stool is the most common method for diagnosing hookworm infection.  The recommended procedure is as follows:
Collect a stool specimen.
Fix the specimen in 10% formalin.
Concentrate using the formalin–ethyl acetate sedimentation technique.
Examine a wet mount of the sediment.
Where concentration procedures are not available, a direct wet mount examination of the specimen is adequate for detecting moderate to heavy infections.  For quantitative assessments of infection, various methods such as the Kato-Katz can be used.

11. Treatment:
In countries where hookworm is common and reinfection is likely, light infections are often not treated.  Hookworm infections are generally treated with
local cryotherapy
Albendazole (400 mg single dose)
Mebendazole (100 mg twice in day for 3 days)
Pyrantel pamoate (10 mg/kg single dose)
Ferrous sulfate (200 mg) be administered three times daily

12. Prevention
Prevalence/ intensity estimation and mass chemotrapy(60% of hookworm in 10%of people)
Do not deficate in places other than latrines, toilets etc.
Do not use human excrement or raw sewage or untreated 'night soil' as manure/fertilizer in agriculture
Deworm pet dogs
Protection of hands and foot for farmers

13. Hook worm In Iran
Necator was common species in the North of Iran and Ancylostoma common speciecs in the South of Iran
Frequency to 70% in North however very low frequency at the moment (less than 1%)
More Common in Farmers and Tourists

14. Cutaneous Larva Migrans ( Dermal larva migrans )
A smaller group of hookworms which infecting animals, can invade and produce eosinophilic enteritis of humans (A. caninum: In Dog) or can penetrate the human skin (A. caninum: In Dog ; A. braziliense: In Cat, Uncinaria stenocephala: In Dog and in Cat) causing cutaneous larva migrans), but do not develop any further.

15. Superfamily : Ancylostomatoidea Family : Ancylostomatidae Subfamily: Ancylostominae and Bunostominae
Ancylostominae: A. brazilense: one pairs teeth /in dog and cat A. duedenale: two pairs teeth /in man A. caninum: three pairs teeth /in dogs A. tubaeforme: three pairs teeth /in cats Globocephalus urosubulatus: without plate or teeth /in swine Placoconus lotoris: with five plates /in raccon Bunostominae: Bunostomum: one pair plates /in ruminants Necator americanus: two pairs plates /in man Bathmostomum: one pair plates /in elephants Gramocephalus :one pairs teeth or plates / in elephants

16. Trichostrongyliasis Causal Agents:
Trichostrongyliasis, which results from infection by Trichostrongylus .orientalis, T.axei, T. probolurus or other closely related species of nematode worms, affects several million people living mainly in rural communities in Asia. worldwide estimated prevalence of 5.5 million .

17. Trichostrongyliasis Life Cycle:
Eggs are 85–115 um, oval, elongated, and pointed at one or both eggs

18. Clinical Featuers:
Symptoms are similar to Hookworm
Light infections are asymptomatic
Heavy infections are characterized by emaciation, anemia, abdominal pain, blood in stool and diarrhea
Diagnosis:
The diagnosis is based on the observation of eggs in the stool. The eggs are 85–115 um, oval, elongated, and pointed at one or both eggs . Trichostrongylus eggs must be differentiated from hookworm eggs which are smaller and do not have pointed ends.

19. Trichostrongyliasis in Iran
Prevalence:
In past: T. orientalis,T. colubriformis, T. vitrinus, T. axei, T. probolurus, T.capricola and T. skrjabini from 7.5% in the northerrn part of Iran to between 69% and 85% in Isfahan in the central part of Iran.
In recently years: More than 18 % in rural area of khuzestan province
Epidemiologic factors on morbidity:
Processing of cow defecate as fuel
Using of un safe water supply
Living at the side of their own domestic animal(cow and sheep)

20. Treatments
Medical
A. Thiabendazole:25 mg/kg twice in days for 2 days
B. Mebendasole: 100 mg 2 tablet in days for 3 days
c. Albendazole:400 mg single dose tablet
D. Pyrantel:10 mg/kg single dose tablet
Veterinary
Levamisole: 2.5 ml/50 kg in cattle

21. Control Cleaning and cooking of vegetables
Avoid from handeling of domestic animal defecate without gloove
Treatment of man and animal at the same time
Water supply sanitation and / or access to portable water supply
Access to fuel Gas

22. References web resurces:
Parasitology Directory (Peter Pappas)
Links to Ecto- and Endo-Parasites in Medical and Veterinary Parasitology
Medical Parasitology :Markel and Voge
کرم شناسی پزشکی دکتر ارفع
انگل شناسی پزشکی دکتر اطهری