dr.morka amante

ADDIS ABABA UNIVERSITYCOLLEGE OF VETERINARY MEDICINE AND AGRICULTURE

DEPARTEMENT OF PARASITOLOGY AND PATHOLOGY

TROPICAL VETERINARY PROTOZOLOGY

REVIEW ON NEOSPORA AND BESNOITIA

By: Morka Amante

The apicomplexan protozoan Neospora spp. is an obligate

intracellular parasite

Neospora caninum is a protozoan parasite infecting primarily

dogs and cattle

It is a globally distributed protozoan capable of infecting a wide

variety of hosts

N. caninum, is a more frequent cause of abortion and stillbirth in

intensive and semi-intensive dairy production in Ethiopia than

the BVD virus and the Brucella bacterium(Asmare,2014).

INTRODDUCTION

NEOSPOROSIS

• Niosporiosis is diseases of protozoan neospora spp which is an obligate intracellular parasite

Etiology• Neospora caninum and Neospora hughesiHost range• dogs, coyotes, and dingoes as definitive hosts for

Neospora caninum and Neospora hughesi• cattle and other ruminants, canines, pig and horses as

intermediate hosts• Horse intermediate hosts for Neospora hughesi• Site infinal host=s.intestine• Site in I.host= schizont indotelial cells of blood vessel,

large cyst containig bradyzoites found in muscle

life cycle

Life cycle of Neospora caninum(slide share)

N. caninum has a worldwide distribution seroprevalence reported in Ethiopia by

Asmare (23.8%). Transmission Horizontally = by the ingestion of oocysts

in feces, Bradyzoites in tissue cysts vertically = transplacental route Neospora caninum DNA has been reported

in bovine semen may be other route

Epidemiology

The risk factors for infection are largely unknown but

evedence suggest that

close contact of cattle with dogs

High stocking densities

Management factors and

concurrent diseases that lead to immunosuppression

may also be important risk factor

Risk factor of the diseases(neosporosis)

Definitive host: Dogs are the final host and sexual phase

occur in them

Intermediate host: Cattle are the major intermediate hosts

and asexual reproduction phase occur in them = from dam

to calf in utero and lactogenically, Infection of cattle can

also occur from the ingestion of food or water

contaminated with dog feces containing Neospora caninum

oocysts = cause of abortion in cattle

Pathogenesis

Tachyzoites penetrate host cell like central nervous

system, muscles, macrophages and other cells, where

they divide rapidly.

Tachyzoites can also be transmitted either with

contaminated food and water or transplacentally to the

fetus in pregnant animals

Tissue cyst containing bradyzoites that these are found only in the nervous system

Cont..

Neosporosis causes

stillbirth

fetal resorption

mummification

Calves are born with neurological symptoms(unable to

stand, unable to suckle, domed skull and torticollis)

abortion and decreases in their milk production

Clinical findings

Effects on production direct cost are dueto abortion Infertility returns to service and loss of milk yield indirect costs through replacements.

Economic importance of the diseases

(IFAT) (ELISA) Histopathology of fetus

Diagnosis

Treatment

No effective drug or vaccine available Suggestions to reduce incidence:

◦Remove all cows infected with Neospora◦Test replacement heifers and newborn calves

◦Reduce stressors (low quality feed stuffs, overcrowding and excessive heat)

◦Prevent horizontal transmission by preventing fecal contamination of cattle feed

Besnoitia spp are a protozoan blood parasite which

causes skin disease in cattle.

The first recorded cases of bovine besnoitiosis were

described in southern France by Cadeac (1884) and by

Besnoit and Robin (1912) in cattle Cause Bovine besnoitiosis (also referred to as bovine

elephantiasis and bovine anasarque) besnoitiosis is either a severe but usually non-fatal

disease of cattle, or a mild clinical disease.

BESNOITIA

Besnoitia are protozoan parasite with classified 9 species, which only 2 of these species are important in livestock animals

species

Etiology

B. Besnoiti B. darling B. tarandiiB. caprae B. Benetti B. Wallacei B. jellisoni, B. akadoni B. oryctofelis

The two common Besnoitia species of animal

Specie Affinity site Intermediat

e hosts

Definitive host

Besnoitia

besnoiti

Skin,

conjunctiva

Cattle Cat, wild cats

(Lion, leopard)

Besnoitia caprae Skin,

conjunctiva

Goats Cat, wild cats

(Lion, leopard)

The complete life cycle of the parasite remains unknown, although seasonal presentation of the disease (mainly in summer and in beef cattle while they are on pastures) suggests an important role for horizontal transmission by

either direct contact, through natural mating or through mechanical transmission by blood-suckling

arthropods

life cycle

Disease occur as outbreaks in tropical and subtropical countries

and sporadically in other countries

Bovine besnoitiosis is common in Africa, Asia and in the South

of Euroup

Caprine besnoitiosis in Keny a, Uganda, Iran, and Kazakhastan

Many aspects of the epidemiology of bovine besnoitiosis remain

uncertain including prevalence and incidence of infection and

disease in endemic areas, routes of transmission and risk-factors

associated to infection and disease

No reported diseases in Ethiopia

Epidemiology

Following infection in cattle or in goats, the tachyzoites proliferate in macrophages, fibroblasts, and endothelial cells and causing vasculitis.

they develop to form bradyzoite cysts in fibroblasts in the derm is, subcutaneous tissues, fascia, nasal and laryngeal mucosa

After developing cysts in the skin, painful subcutaneous swelling, thickening of the skin, alopecia, and necrosis can be occur

Sterility in males is caused by a necrotizing orchitis. Death may occur in both the anasarca and scleroderma stages of the disease, regardless of the sex of the animal

Pathogenesis

In bovine besnoitiosis

The acute anasarca stage

include fever, increase in pulse and respiratory rates,

painful swelling on the ventral aspects of the body, edema

of the skin, sometimes diarrhea, lacrimation and nasal

discharge

The chronic scleroderma stage

mainly associated with cyst formation In chronic stage,

there is a severe dermatitis over most of the body

Clinical findings

In Caprin besnoitiosis

Thickening of the skin over the lower limbs , around the

eyes, nose, face and scrotum, alopecia in all of these areas,

and

white granular cysts in the sclero-conjunctiva can be seen

Cont……

Horizontal transmission is probably the main method of

transmission of infection =occurs as a consequence of

direct contact among animals with wounds or

lacerations

infected bulls in natural mating

mechanically by blood-sucking arthropods, such as

horseflies and deer flies

bovine besnoitiosis has not been reported to infect

humans.

Transmission of besnoitiosis

Seasonality factors= majority of new cases occur during

the warmer, moister months of the year

Age factors =The highest incidence of infection was

detected in adult animals on a farm where the disease was

present, but was rarely encountered in calves under 6

months of age

Sub-clinical carriers as factor= The existence of blood-

sucking flies could be a risk factor for the rapid spread of

the disease

Risk factors for besnoitiosis

disease causes a serious illness both during the acute and

chronic phases that could compromis animal welfare

Bovine besnoitiosis leads to significant economic losses by

a decline in milk production,

sterility,

transient or permanent infertility of bulls,

skin lesions and increase of mortality in affected cattle

population

Economic and welfare impact of besniotiosis

Besnoitiosis can be diagnosed by demonstration of B.

bradyzoites in skin biopsy smears or scleral conjunctival

scrapings

A number of diagnostic tests such as

cytology

histopathology

serology and PCR testing are available

Diagnosis of besnotiosis

there are not any effective drugs(no known treatment)

for this disease or vaccines available

a live-attenuated vaccine has been used(s. Africa and

Israeli).

Control is effected by the elimination of infected

animals and carriers, and early diagnosis

Treatment and Control of besniotiosis

THANK YOU