1. Dracunculus medinensis

2. Taxonomy
Common names- Guinea Worm, Medina Worm, Serpent Worm, Dragon Worm

3. History Known as a parasite of humans since about 1530 B.C.
Guinea worm is thought to be the "fiery serpent" referred to in the Bible.
The symbol of a Physician is the "Caduceus". The serpents are believed to represent the Guinea worm.
Persian physicians removing the D. medinensis parasite from patient during the 9th century-

4. Hosts
Definitive: Humans
Intermediate: Copepod

5. Distribution
Except for a few remote villages in the Rajastan desert of India and in Yemen, Guinea worm disease now occurs only in Africa.
Infected areas in Africa lie in a band between the Sahara and the equator.
Presently, only 9 countries are endemic: Sudan, Ghana, Nigeria, Mali, Togo, Burkina Faso, Ethiopia, Niger, and Ivory Coast.
>50% of all cases of Guinea worm disease are reported from southern Sudan.

6. Morphology
A: Adult D. medinensis worms. (A) The adult female guinea worm is a long, slender worm ranging from 30 to 120 cm in length and from 0.09 to 0.17 cm in width.
B: Three mature guinea worms.
Note the tiny size of the mature male (mm) compared with the mature female (mf) and especially the markedly elongated and serpiginous, gravid female worm (gf). The gravid female shows an extruded uterus (eu)

7. Characteristics usually occurs during drought
Everyone is forced to drink from the same stagnant water supplies or pay for well.
Three conditions to be met before D. medinensis can complete it’s life cycle.
The skin of an infected individual must come in contact with water
The water must contain the appropriate species of microcrustacean
The water must be used for drinking
Believed the parasites feed on blood due to the gut often being filled with dark brown gut material

8. Life Cycle

9. Life Cycle
Humans become infected by drinking unfiltered water containing copepods (small crustaceans) which are infected with larvae of D. medinensis
Following ingestion, the copepods die and release the larvae, which penetrate the host stomach and intestinal wall and enter the abdominal cavity and retroperitoneal space.
The worm molts again 20 days and 43 days post infection
Females are fertilized by the third month.
After maturation into adults and copulation, the male worms die and the females (length: 70 to 120 cm) migrate in the subcutaneous tissues towards the skin surface
Approximately one year after infection, the female worm induces a blister on the skin, generally on the distal lower extremity, which ruptures. 
When this lesion comes into contact with water, which the patient seeks to relieve the local discomfort, the female worm emerges and releases larvae
The larvae are ingested by a copepod and after two weeks (and two molts) have developed into infective larvae

10. Epidemiology
Dracunculiasis may result in three major disease conditions
Emergent adult worms
Secondary bacterial infection
Nonemergent worms
When worms do not emerge they degenerate and release antigens causing fluid filled abscesses or allergenic reactions.
If the worms become calcified they can cause inflammation or if they remain in a joint, arthritis.
Can cause paraplegia if it worm gets into the central nervous system.

11. Pathology
None until the female worms cause an allergic reaction by releasing metabolic wastes into host. This occurs at the onset of migration to the skin.
a rash accompanied by severe itching
nausea
vomiting
diarrhea
dizziness
edema
Reddish papule-blister (local itching and intense burning).
Blister ruptures, becomes abscessed-very painful.
Secondary bacterial infections of opening possible.
Retreating worm can draw bacteria under skin as well.
There may be later symptoms
fibrosis of the skin, muscles, tendons and joints (may interfere with locomotion or use of limbs)
Ruptured Blister
Blister

12. Pathology
Adult in joint 
Calcified lesion in soft tissues 

13. Diagnosis Diagnosis is made from the local blister, worm or larvae.
The outline of the worm under the skin.
Some people claim to be able to feel the worm moving towards the surface of the skin.
Finding Calcified worms.

14. Treatment Drug Therapy—Metronidazole
To help prevent bacterial infections
Anti-inflammatory to help reduce swelling
Treatment includes the extraction of the adult guinea worm by rolling it a few centimeters per day
Usually takes weeks or months depending on how long the worm is.
Exposing area to cold water helps remove worm faster.
Preferably by multiple surgical incisions under local anesthesia.
Infection does not make a person immune

15. Control
Filter, boil, or treat water with chlorine to kill intermediate host.
Finely-meshed cloth or, better still, a filter made from a 0.15 mm nylon mesh, is all that is needed to filter out the copepods from the drinking water.
Avoid bathing or wading in drinking water.
Village-based volunteers demonstrating the use of cloth filter on a clay pot to filter drinking water     

16. Loa Loa

18. Morphology Usually found in Africa and India
Has a simple body with a head and neck
Males are about mm long
Females are about mm long

19. para-lab by l. wafa menawi
Loiasis
Microfilariae in human blood
Loa loa Adult worms move under human skin
Observed beneath skin or passing through conjunctiva of eyes (‘eye worms’)
Transmitted by horse flies in genus Chrysops
Disease endemic to rain forest regions of West & Central Africa and india
Generally mild & painless (chronic) with year incubation period
May cause swellings of skin (Calabar swelling)
para-lab by l. wafa menawi

20. Life cycle
A vector fly bites an infected human host and ingests microfilariase.
Microfilariae move to the thoracic muscles of the insect host.
Microfilariae develop into first stage larvae, then third stage larvae.
Third stage larvae (infective) travel to the proboscis of fly.
An infected vector fly bites an uninfected human host and the third stage larvae penetrates the skin and enters human subcutaneous tissue.
Larvae mature into adults, who produce microfilariae that have been found in spinal fluid, urine, peripheral blood, and lungs.

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22. Disease
Loa Loa infect human host by migrating through subcutaneous tissue such as back, chest, groin, scalp and eye.
The parasite causes infection wherever they travel, and if they stay local, the host will suffer from local infection known as Calabar Swellings

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Diagnosis
The standard method for diagnosing active infection is the identification of microfilariae by microscopic examination
However, microfilariae circulate nocturnally, making blood collection an issue
Presence of worm in eye
Skin swelling (nodules)
para-lab by l. wafa menawi

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Diagnosis
A “card test” for parasite antigens requiring only a small amount of blood has been developed
Does not require laboratory equipment
Blood drawn by finger stick
Urinalysis, CBC and Comprehensive Chemistries
Foot Biopsy: Normal Skin with areas of chronic inflammation
para-lab by l. wafa menawi

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Treatment
Treatment of filariasis involves two components:
Getting rid of the microfilariae in people's blood
Maintaining careful hygiene in infected persons to reduce the incidence and severity of secondary (e.g., bacterial) infections.
Surgical removal of the worm
para-lab by l. wafa menawi

26. Drugs Anti-filariasis medicines commonly used include:
Diethylcarbamazine (DEC)
reduces microfilariae concentrations
kills adult worms
Albendazole