HELMINTH: CHAPTER 9

NEMATODA

ROUND WORMS

HEART WORM

COMMON NAME OF DIROFILARIA IMMITIS

CARNIVORES, MAN, HORSES

DIROFILARIA IMMITIS HOST

RIGHT VENTRICLE, PULMONARY ARTERIES, SCROTUM

DIROFILARIA IMMITIS P.S.

MICROFILARIAE

LARVAE OF DIROFILARIA IMMITIS, IDEAL TO COLLECT AT 8PM

OVOVIVIPAROUS

DIROFILARIA IMMITIS FEMALE MORPHOLOGY

SPIRALLY COILED

DIROFILARIA IMMITIS MALE MORPHOLOGY

MECHANICAL TRAUMA

LIVE HEARTWORMS ARE THOUGHT TO CAUSE

ANTIGENS, SECRETIONS

thought to directly irritate or to stimulate the hosts’ immune system

IMMUNOSUPRESSIVE EFFECT

EFFECT OF LIVE HEARTWORMS

VASCULAR REACTIONS

EFFECT OF DEAD HEARTWORMS

PULMONARY HYPERTENSION

EFFECT OF HEARTWORMS IN ACTIVE DOGS

PRECIPITATING VENA CAVA SYNDROME

High exposures in young, naive dogs in temperate climates can

result in severe infections, possibly

WOLBACHIA PIPIENS

intracellularly within the filarid parasite, is still being

determined.

DOXYCYCLINE

TREATMENT FOR D. IMMITIS AND W. PIPIENS

MACROLIDE PROPHYLAXIS

PREVENTS HEARTWORM INFECTION

CATTLE, BUFFALO

HOST OF ELAEOPHORA POELI

DEER, ELK, SHEEP

HOST OF ELAEOPHORA SCHNEIDERI

ELAEOPHORA

Site	Wall of Aorta
I.H.	Tabanids are implicated as I.H
Morphology	· Males – are found in the wall of the aorta · Females – fixed in the nodules with their ant. Extremity dug in the nodules

WALL OF AORTA

PREDILECTION SITE OF ELAEOPHORA

TABANIDS

INTERMEDIATE HOST OF ELAEOPHORA

HORSES

HOST OF PARAFILARIA

SUBCUTANEOUS AND INTRAMUSCULAR CONNECTIVE TISSUE

PREDILECTION SITE OF PARAFILARIA

BLOODY SWEAT WORM

COMMON NAME FOR PARAFILARIA MULTIPAPILLOSA

MUSCA AND HAEMATOBIA

I.H. FOR PARAFILARIA MULTIPAPILLOSA

MUSCA

I.H FOR FARAPILARIA BOVICOLA

MAN AND PRIMATES

HOST OF LOA LOA

SUBCUTANEOUS TISSUE OF THE EYE

PREDILECTION SITE FOR LOA LOA

CHRYSOPS

I.H. OF LOA LOA

PARAFILARIA MULTIPAPILLOSA

SUMMER BLEEDING ONLY DAYLIGHT HOURS

ARTERIAL WORM

COMMON NAME FORELAEOPHORA POELI

LOIASIS

filarial nematode infection with Loa loa.

LOAISIS

Symptoms include localized angioedema (Calabar swellings) in skin and subconjunctival migration of adult worms.

DIETHYCARBAMAZINE, ALBENDAZOLE, APHERESIS

TREATMENT FOR LOA LO

MONKEY, CARNIVORE

BRUGIA MALAYI HOST

LYMPHATIC SYSTEM

PREDILECTION SITE OF BRUGIA MALAYI

MOSQUITOES

I.H. OF BRUGIA

MAN, CAT

HOST OF BRUGIA PAHANGI

ELEPHANTIASIS

ANOTHER TERM FOR LYMPHATIC FILARIASIS

ELEPHANTHIASIS

neglected tropical disease. Infection occurs when filarial parasites are transmitted to humans through mosquitoes. Infection is usually acquired in childhood causing hidden damage to the lymphatic system

ELEPHANTIASIS

Caused by fluid collection because of improper functioning of the lymph system resulting in swelling

ELEPHANTIASIS

This mostly affects the legs, but can also occur in the arms, breasts, and genitalia. Most people develop these symptoms years after being infected

NOCTURNAL PERIODICITY

The microfilariae that cause lymphatic filariasis circulate in the blood at night

DIETHYLCARBAMAZINE

TREATMENT FOR BRUGIA (ELEPHANTIASIS)

MAN

HOST OF WUCHERARIA BANCROFTI

LYMPHATIC SYSTEM

PREDILECTION SITE FOR WUCHERARIA BANCROFTI

MOSQUITOES

I.H. FOR WUCHERIA BANCROFTI

WUCHERIARIA BANCROFTI

ALSO CAUSES ELEPHANTIASIS

HORSES

HOST OF SETARIA EQUINA

PERITONEAL, PLEURAL, SCROTUM, LUNGS, LIVER

PREDILECTION SITE OF SETARIA EQUINA

MOSQUITOES

I.H. OF SETARIA EQUINA

CEREBROSPINAL NEMATODOSIS

CAUSED BY SETARIA EQUINA WHEN IT MIGRATED TO CNS

STEPHANOFILARIA DEDOESI

Morpho-logy

Chronic dermatitis of cattle called cascado; Verminous dermatitis, cascado

S. DIGITATA, S. LABIATO-PAPILLOSA, S. MARSHALI

Host	Found in Large ruminants

SETARIDAE

Causes a circumscribed dermatitis along the ventral midline of cattle

PIG

HOST OF ASCARIS SUUM

LARGEST AND MOST COMMON PIG NEMATODE

COMMON NAME FOR ASCARIS SUUM

ASCARIS SUUM

Morphology

· Males are up to 25 cm and females up to 40 cm long, whitish, and quite thick · Large numbers of eggs are produced (as many as 200,000 to 1 million/day per female) · Direct LC ingestion of L2 in contam. water and food

SMALL INTESTINE

ADULT PREDILECTION SITE FOR ASCARIS SUUM

LIVER, LUNGS

IMMATURE PREDILECTION SITE FOR ASCARIS SUUM

ASCARIS SUUM

Highly resistant to chemical agents; however, conditions with low humidity, heat, or direct sunlight decrease their survival time.

EARTHWORMS, DUNG BEETLES

PARATENIC HOST OF ASCARIS SUUM

ASCARIS SUUM

decrease the growth rate of young pigs; in rare cases, the worms may cause mechanical obstruction of the intestine

MILK SPOTS

Migration of ASCARIS SUUM larvae through the liver causes hemorrhage, fibrosis, and accumulation of lymphocytes seen as white spots under the capsule, leading to condemnation of the liver at slaughter.

LARVA MIGRANS

Larvae that reenter the alveolar blood vessels travel to the muscles or organs, where they become encysted and their development is arrested

ANTHELMINTHICS

TREATMENT FOR ASCARIS SUUM

HORSES

HOST OF PARASCARIS EQUORUM

SMALL INTESTINE

ADULT P.S. OF PARASCARIS EQUORUM

LIVER, LUNGS

IMMATURE P.S. OF PARASCARIS EQUORUM

PARASCARIS EQUORUM

Condition Cause/ Distinguishing Char.

· Immature in liver – focal hemo. · Eosinophilic Tracts Lung - hemo. · Lymphocytic nodules

TOXOCARA CATI, TOXOCARA CANIS, TOXASCARIS LEONINA

ARROW HEADED WORMS

DOGS

HOST OF TOXOCARA CANIS

TOXOCARA CANIS

Distinguishing Char.

· No migratory phase after Transmammary infection with L3 · Visceral larva migrans

CATS

HOST OF TOXOCARA CATI

TOXOCARA CATI

Distinguishing Char.

No prenatal infection

CATS AND DOGS

HOST OF TOXASCARIS LEONINA

SMALL INTESTINE

P.S. OF TOXOCARA

LARGEST INTESTINAL PARASITE OF CATTLE

TOXOCARA/NEOSCARIS VITULLORUM COMMON NAME

TOXOCARA CANIS, TOXOCARA CATI

Confirmed ZOONOTIC species

TRANSMAMMARY ROUTE

TRANSMISSION OF TOXOCARA CATI

VISCERAL LARVA MIGRANS

occurs mostly in preschool children, the larvae invade multiple tissues (commonly liver, lung, skeletal muscle, occasionally heart) and cause various nonspecific symptoms (e.g. fever, myalgia, weight loss, cough, rashes, hepatosplenomegaly) usually accompanied by hypereosinophilia.

VISCERAL AND OCULAR LARVAL MIGRANS

COMMON PRESENTATION OF TOXOCARIASIS

SEROLOGY, ANTI-BODY DETECTION

DIAGNOSIS OF TOXOCARIASIS