Dracunculiasis Dracunculiasis Terry L Dwelle Dwelle MD MPHTM MD - PowerPoint PPT Presentation

Dracunculiasis Dracunculiasis Terry L Dwelle Dwelle MD MPHTM MD MPHTM Terry L

Classification of Nematodes Classification of Nematodes Subclass Order Superfamily Genus and Probable Subclass Order Superfamily Genus and Probable (suborder) Species prevalence (suborder) Species prevalence in man in man Secernentea Secernentea Spirurida Spirurida Dracunculoidea Dracunculoidea Dracunculus Dracunculus 10 million 10 million (Camallanina Camallanina) ) medianesis ( medianesis

General General ► Etiology ► Etiology - - Dracuncula Dracuncula medianensis medianensis causing causing Guinea Worm Infection Guinea Worm Infection ► Geographic distribution ► Geographic distribution – – Africa (12 Africa (12 countries West, Central and East Africa countries West, Central and East Africa ► 32,000 cases with 63% in Sudan (2003) ► 32,000 cases with 63% in Sudan (2003)

General Recognition Features General Recognition Features ► Size ► Size – – Female 60 Female 60- -120 cm, male 1.2 120 cm, male 1.2- -2.9 cm 2.9 cm ► Larvae ► Larvae – – 500 500- -750 um long 750 um long

Life Cycle Life Cycle ► Definitive host ► Definitive host – – man man ► Where the adults live in the body ► Where the adults live in the body – – deep deep connective tissues connective tissues ► Stage leaving the body ► Stage leaving the body – – L1 larvae from an L1 larvae from an adult worm in a skin lesion adult worm in a skin lesion ► Intermediate host ► Intermediate host – – Cyclops (copepod) Cyclops (copepod) small crustaceon crustaceon small ► Infectious stage for the definitive host ► Infectious stage for the definitive host – – ingestion of an infected cyclops cyclops ingestion of an infected

Life Cycle Life Cycle Ingestion of an infected Cyclops Deep connective tissues Migrate for about 1 year Cyclops L3 larvae in 10d – 2w Gravid female moves to skin Discharges larvae through cutaneous ulcer (into water)

Life Cycle Life Cycle ► Prepatent ► Prepatent period period – – 12 months 12 months

A Colour Atlas of Tropical Medicine From A Color Atlas of Tropical Medicine and Parasitology, 2nd edition, and Parasitology, 2 nd Edition, Year From A Color Atlas of Tropical Medicine and Parasitology, 2nd From A Color Atlas of Tropical Medicine and Parasitology, 2 nd Book Medical Publishers, 1981, pp Peters and Gilles, Year Book Medical Publishers, 1981 edition, Peters and Gilles, Year Book Medical Publishers, 1981 edition, Peters and Gilles, Year Book Medical Publishers, 1981 257

Disease Characteristics Disease Characteristics ► Generally no symptoms in the prepatent prepatent period period ► Generally no symptoms in the ► Prodrome stage stage – – few hours prior to skin lesions an few hours prior to skin lesions an ► Prodrome erythematous urticarial urticarial rash is seen with rash is seen with pruritus pruritus, nausea, , nausea, erythematous diarrhea, dyspnea dyspnea, syncope, giddiness , syncope, giddiness diarrhea, ► ► Skin lesion – – red papule, vesicle with red papule, vesicle with indurated indurated margin margin Skin lesion (1.5- -2.0 cm) mainly on feet and ankles. With rupture 2.0 cm) mainly on feet and ankles. With rupture (1.5 some of the symptoms abate but may recur with removal some of the symptoms abate but may recur with removal of the worm. of the worm. ► ► Sterile abscess – – if the worm fails to reach the skin surface if the worm fails to reach the skin surface Sterile abscess and dies and dies ► Secondary infection is common ► Secondary infection is common ► When close to joints may cause a debilitating arthritis ► When close to joints may cause a debilitating arthritis ► ► Can rarely migrate to critical organs Can rarely migrate to critical organs

From A Color Atlas of Tropical Medicine and Parasitology, 2nd edition, Peters and Gilles, Year Book Medical Publishers, 1981 From A Color Atlas of Tropical From A Color Atlas of Tropical Medicine and Medicine and Parasitology, 2nd Parasitology, 2nd edition, Peters and Gilles, Year Book edition, Peters and Gilles, Year Book Medical Publishers, 1981 Medical Publishers, 1981

Diagnosis Diagnosis ► Clinical suspicion ► Clinical suspicion – – prodrome prodrome followed by followed by the classic skin lesion. the classic skin lesion.

Treatment Treatment ► Slow extraction of the worm combined with wound ► Slow extraction of the worm combined with wound care care ► Metronidazole Metronidazole ► � Adults � Adults – – 250 mg 250 mg tid tid X 10 days X 10 days � Children � Children – – 25 mg / kg / day (maximum 750 mg) divided 25 mg / kg / day (maximum 750 mg) divided into 3 doses X 10 days into 3 doses X 10 days � Not curative but decreases inflammation and facilitates � Not curative but decreases inflammation and facilitates worm removal worm removal � Metronidazole � Metronidazole 400 400- -800 mg / day for 6 days has been 800 mg / day for 6 days has been reported to kill the worm directly reported to kill the worm directly The Medical Letter, August 2004, Drugs for Parasitic Infections, pp 1-12

Metronidazole Adverse Reactions Adverse Reactions Metronidazole st trimester ► 1 st ► Avoid – – 1 trimester Avoid ► Use with caution CNS disease, blood dycrasias dycrasias, severe liver , severe liver ► Use with caution CNS disease, blood or renal disease (GFR < 10 mL mL/min) /min) or renal disease (GFR < 10 ► ► Adverse reactions – – nausea, diarrhea, nausea, diarrhea, urticaria urticaria, dry mouth, , dry mouth, Adverse reactions leukopenia, vertigo, metallic taste, peripheral neuropathy , vertigo, metallic taste, peripheral neuropathy leukopenia ► May worsen candidiasis candidiasis ► May worsen ► ► May cause disulfirim disulfirim type reaction with alcohol type reaction with alcohol May cause consumption within 24- -48 hours after dose given 48 hours after dose given consumption within 24 ► ► May increase levels of toxicity of phenytoin phenytoin, lithium, and , lithium, and May increase levels of toxicity of warfarin. . warfarin ► ► Phenobarbital and rifampin rifampin may decrease may decrease metronidazole metronidazole Phenobarbital and metabolism metabolism

Control Measures Control Measures ► Protected wells and water supplies ► Protected wells and water supplies ► Temphos ► Temphos (Abate) treatment of water (Abate) treatment of water supplies supplies ► Appropriate treatment of infected ► Appropriate treatment of infected individuals individuals ► Boiling or filtering ( ► Boiling or filtering (eg eg nylon filter) of nylon filter) of potentially infected water potentially infected water