CyclophyllideaCyclophyllidea

• Taenia saginataTaenia saginata

• Taenia soliumTaenia solium

• Echinococcus granulosusEchinococcus granulosus

• Echinococcus multilocularisEchinococcus multilocularis

• Hymenolepis diminutaHymenolepis diminuta

• Hymenolepis nanaHymenolepis nana

• Dipylidium caninumDipylidium caninum

Taenia saginataTaenia saginata

• Beef tapewormBeef tapeworm

• Get infected by eating beefGet infected by eating beef

• 3-5 meters (20 meters)3-5 meters (20 meters)

Bovid eats egg. Oncosphere hatches, penetrate mucosa and enter blood stream. Go to muscle and develop into a cysticercus

Adults in intestine. Gravid proglottids shed in feces. Proglottid degrades and eggs released

Human eats cysticerci with muscle. Scolex evaginates and attaches to small intestine

Taenia saginata Taenia saginata PathogenesisPathogenesis

• Not very pathogenicNot very pathogenic• Worm produces antigens = allergic reactionWorm produces antigens = allergic reaction• Abdominal discomfortAbdominal discomfort• DiarrheaDiarrhea• NauseaNausea• Abdominal PainAbdominal Pain• DizzinessDizziness• Loss of apetiteLoss of apetite• Obstruction of intestine if intensity is highObstruction of intestine if intensity is high

Taenia saginata Taenia saginata Diagnosis and TreatmentDiagnosis and Treatment

• Look for _____________ in feces.Look for _____________ in feces.

• ELISAELISA

• PraziquantelPraziquantel

EpidemiologyEpidemiology

• How do you get infected?How do you get infected?

• How do bovids get infected?How do bovids get infected?

Taenia soliumTaenia solium

Taenia soliumTaenia solium

• Pork tape wormPork tape worm• Most dangerous cestode?Most dangerous cestode?

– Humans areHumans are• Definitive hostsDefinitive hosts• Intermediate hostsIntermediate hosts

• CosmopolitanCosmopolitan– MexicoMexico– Central AmericaCentral America– South AmericaSouth America– IndiaIndia– ChinaChina– AsiaAsia

Taenia soliumTaenia solium

Pig eats egg. Oncosphere hatches, penetrate mucosa and enter blood stream. Go to muscle and develop into a ____________

Adults in intestine. Gravid proglottids shed in feces. Proglottid degrades and eggs released

Human eats cysticerci with muscle. Scolex evaginates and attaches to small intestine.

Adults in intestine. Gravid proglottids shed in feces. Proglottid degrades and eggs released

Human eats egg. Oncosphere hatches, penetrate mucosa and enter blood stream. Go to muscle and develop into a ____________

Dead End

PathogenesisPathogenesis

• AdultsAdults– Not seriousNot serious

• CysticerciCysticerci– CysticercosisCysticercosis

– Establish in many tissuesEstablish in many tissues• Connective tissues Connective tissues

• BrainBrain

• EyeEye

• MusclesMuscles

• HeartHeart

• LiverLiver

• LungsLungs

Human muscular cysticercosis

Human Neurocysticercosis and Ophtalmocysticercosis

CysticercosisCysticercosis• Seriousness depends onSeriousness depends on

– LocationLocation– NumberNumber– Immune responseImmune response

• FibrosisFibrosis• Damage to eyeDamage to eye• BrainBrain

– EpilepsyEpilepsy– Nervous system malfunctionNervous system malfunction– BlindnessBlindness– ParalysisParalysis– DisorientationDisorientation

• Mechanical PressureMechanical Pressure• Cysticerci begin to degenerateCysticerci begin to degenerate• Inflammatory responseInflammatory response

– BrainBrain– eyeeye

DiagnosisDiagnosis

• Look for _____________ in feces.Look for _____________ in feces.

• ELISAELISA

• MRIMRI

• X-raysX-rays

• Eggs with well developed hexacanth and Eggs with well developed hexacanth and striated embryophore; 35-40 x 30-32 striated embryophore; 35-40 x 30-32 µm.µm.

EggsEggs

Treatment and PrognosisTreatment and Prognosis

• NiclosamideNiclosamide– Only acts on adultsOnly acts on adults

• PraziquantelPraziquantel– Can kill cysticerciCan kill cysticerci

– Death elicits immune responseDeath elicits immune response

– Brain: SeizuresBrain: Seizures

– Is this worse than natural progression?Is this worse than natural progression?

– SteroidsSteroids

• Surgery Surgery

EpidemiologyEpidemiology

• How does a human get infected with adults?How does a human get infected with adults?

• How does a human get infected with How does a human get infected with cysticerci?cysticerci?

• AutoinfectionAutoinfection

Santo Domingo, a rural community in the state of Yucatan.

Pigs acquire cysticercosis because….

Pigs acquire cysticercosis because….

Pigs acquire cysticercosis because….

Swine cysticercosis

Differential DiagnosisDifferential Diagnosis

• Taenia soliumTaenia solium and and Taenia saginataTaenia saginata

• Importance?Importance?

7-13 15-20 7-13 15-20

StatisticsStatistics

• EpilepsyEpilepsy– 1.7% Ecuador1.7% Ecuador– 2.1% Columbia2.1% Columbia– 3.7% Nigeria3.7% Nigeria

• 6 times higher than developed nations6 times higher than developed nations

• MexicoMexico– 12% neurological hospital beds12% neurological hospital beds

Economic CostEconomic Cost

• $15 million Mexico for hospital admission$15 million Mexico for hospital admission

• Pork industry MexicoPork industry Mexico– $43 million in meat loss$43 million in meat loss

Taenia soliumTaenia solium• Emerging Infectious Diseases March 2004Emerging Infectious Diseases March 2004

OregonOregon CaliforniaCalifornia

YearsYears 1995-20001995-2000 1989-20001989-2000

# Cases# Cases 4343 ??

# Deaths# Deaths 66 124124

Born in MexicoBorn in Mexico 72%72% 72.6%72.6%

% from US% from US 18%18% 14%14%

Age at deathAge at death 3333 39.939.9