Parasites causing pneumoniapneumoniapneumoniapneumonia.ppt

pneumonia

1. Parasites causing Pneuomonia
Prof. Dr. Eman Mobarak Hussein

2. Objectives
1 .List parasites causing pneumonia
2 -Define larva migration
3 -Describe the life cycle of Ascaris lumbercoides
4 -Define visceral larvae migrans
5 -Identify the parasites causing visceral larvae migrans
6 -Describe modes of infection of visceral larvae
migrans
7 -List methods of diagnosis of visceral larvae migrans

3. Parasites affecting Respiratory
system ± causing pneumonia

4. Parasites causing pneumonia
1-Shistosoma on the lung & Katyama fever
2- Paragonimus westermani
2- Ascaris lumbercoides
3- Ancylstoma duodenal
4- Strogolyoides stercoralis
5- Toxocara
6- Trichenella
5- Toxoplasma gondii
6- Leishmania
7- Cryptosporidium
9- Plasmodium falciparum

5. Larvae migrans
Larvae migrans is a condition in humans caused by the migratory larvae of certain
 
nematodes
1- A condation resulting from invasion of the skin (cutaneous larvae migrans =
creeping eruption) by non human nematodes filariform larvae (Anc. braziliense &
Ancy. caninum).

2-If this condition resulting from migration (visceral larvae migrans/ ocular larvae
migrans ) of nematodes larvae on an unnatural host e.g. Toxocara cati & toxocara
canis.

6. Ascaris lumbricoides
Morphology
1-Adults are large, thick, white worms.
Male is 20 cm. Female is 30 cm
2-Eggs in feces;
A-fertile Shape; oval
-Color; Yellowish brown,
-Mamillated external layer of the thick shell (decortecated . -/
cortecated )
b- unfertile: Shape; Rectangular
-The well-defined ovum is in the one-cell stage passes in stool

7. Life cycle

8. 1-Adult worms
  live in the lumen of the small intestine
.
2 -Immature Eggs are passed with the feces .
 
3-Fertile eggs embryonate and become infective 18 days
to weeks
 , depending on the environmental conditions
(optimum: moist, warm, shaded soil) .
4-After infective eggs are swallowed
 , the larvae hatch ,
invade the intestinal mucosa, and are carried via the
portal, then systemic circulation to the lungs .
 
5-The larvae mature further in the lungs (10-14 days),
penetrate the alveolar walls, ascend the bronchial tree
to the throat, and are swallowed .
 
6-Upon reaching the small intestine, they develop into
adult worms
 . Between
2 and 3 months are required
from ingestion of the infective eggs to oviposition by
the adult female. Adult worms can live 1 to 2 years

9. Disease: Roundworm infection Ascariasis.
Clinical effects:
1- The larvae in the lungs can cause pneumonitis, with cough, chest
pain and difficulty in breathing.
2- The few adult parasites present (mean number is 6) result in minor
symptoms or non.
3- Large numbers of parasites (over 100) can result in digestive
disorders and, particularly in children, protein energy malnutrition.
4- Intestinal obstruction results in symptoms of severe abdominal pain
and vomiting, parasites in the bile duct lead to severe colicky pains
and cholangitis.
5- Ascaris are easily irritated and can wander out through the mouth or
nose or become embedded in abdominal stitches.

10. Portion of small intestine completely blocked by Ascaris.

11. Diagnosis:
1- This is usually made by detecting Ascaris eggs in the faeces.
2- Adults Ascaris can often be diagnosed as a filling defect in straight X-
rays of the abdomen.
3- In migration phase larvae present in sputum
4- Duodenal aspiration/ entero (capsule or string) test

12. Visceral larvae migrans is a condition in humans
caused by the migratory larvae of certain
 
nematodes, humans being a
 dead-end host
,
These nematodes can infect but not mature in
humans and after migrating through the
intestinal wall, travel with the blood stream to
various organs where they cause inflammation
and damage .

13. Nematodes causing such
 zoonotic infections are
 
Baylisascaris procyonis
Toxocara canis
Toxocara cati 
 Ascaris suum 
Affected organs can include the
 liver,
lung
(pneumonia )
 heart (causing myocarditis) and
the
 CNS (causing dysfunction, seizures, and coma).
A special variant is
 ocular larva migrans where
usually
 
T. canis 
larvae travel to the eye

14. Life cycle of Toxocara Spp.

15. Humans are not the only accidental hosts of
 
Toxocara 
 .
Consumption of undercooked rabbit, chicken, and
sheep can lead to infection; encysted larvae in the
meat can become reactivated and migrate through a
human host.
Both
 
Toxocara canis 
and 
Toxocara cati 
eggs require a
several week outside of the host before becoming
infective.
Three syndromes
1-Covert toxocariasis ,
2-Visceral larva migrans (VLM) ,
3-and ocular larva migrans (OLM)

16. 1-Covert toxocariasis
least serious and is believed to be due to chronic
exposure.
 
 
Signs and symptoms of covert toxocariasis are
coughing, fever, abdominal pain, headaches, and
changes in behavior and ability to sleep.
 

 
Upon medical examination, wheezing, hepatomegaly,
and lymphadenitis are often noted.

17. 2-Visceral larva migrans (VLM).
High parasitic loads or repeated infection can lead to
VLM 
.
 it is primarily diagnosed in young children, because
they are more prone to exposure and ingestion of
infective eggs.

 
Toxocara 
infection commonly resolves itself within
weeks, but chronic eosinophilia may result.
 
  
In VLM, larvae migration incites inflammation of
internal organs and sometimes the central nervous
system.
 
 

18. Symptoms depend on the organ(s) affected.

 
 
Patients can present with pallor, fatigue, weight loss,
anorexia, fever, headache, rash, cough, asthma,
chest tightness, increased irritability, abdominal
pain, nausea, and vomiting.
Patients are commonly diagnosed with pneumonia,
bronchospasms, chronic pulmonary inflammation,
hepatomegaly.,

19.  
 
 
Laboratory diagnosis of VLM
-Hypergammaglobulinaemia (IgM, IgG, and IgE
classes) ELISA
-Leucocytosis
-Hypereosinophilia ,
-Elevated anti-A and –B isohaemagglutinins.
Severe reactions have occurred in people with atopy;,
epilepsy, myocarditis, pleural effusion, respiratory
failure, and death have resulted from VLM
-The biopsy is the gold standard in diagnosis of larvae
migrans

20. 3-Ocular larva migrans (OLM)

A light
 
Toxocara
 
burden is thought to induce a low immune response,
allowing a larva to enter the host’s eye.
 
Although there have been cases of concurrent OLM and VLM
 
OLM is often unilateral and from a single larva migrating into and
encysting within the orbit.

 
 
Loss of vision occurs over days or weeks.
4
 
 
Toxocara
 
damage in the eye is permanent and can result in blindnes

21. Thank you