Varicella zoster virus presentation

1. Parasitic Infections in the
Compromised Host
BY- Sanju Sah
St. Xavier’s college, Maitighar, Kathmandu
Department of Microbiology

3. Sarcodina

4. Human
Parasites
Protozoa
Lumen dwelling and intestinal
protozoa Blastocystis
Amoebae Entamoeba histolytica
Flagellates Giardia lamblia, Trichomonal vaginalis
Ciliates Balantidium coli
Sporozoa Isospora belli
Coccidia Cryptosporidum spp. Cryptosporidium parcum, Cyclospora cayetanensis
Other blood and tissue dwelling
sporozoa Plasmodium, Trypanosoma, Leishmania
Tissue coccidia Toxoplasma gondii, Sarcocystis
Opportunistic free living
amoeba Acanthamoeba, Naegleria fowleri, Balamuthia mandrillaris, Sappinia spp
Trematodes
Intestinal flukes Fasciolopsis buski
Blood flukes Schistosoma mansoni
Liver flukes Fasciola hepatica
Lung flukes Paragonimus Westermanii
Cestodes Taenia solium, T. Saginata, T. saginata asiatica, Echinococcus granulosus, Hymenolepis nana
Intestinal nematodes
Ascaris lumbricoides,Trichuris trichura, Ancyclostoma duodenale, Nectar americanus,
Stongyloides stercolaris, Enterobius vermicularis
Blood and tissue dwelling
nematodes Wuchereria brancofti, Oncocerca volvulus
other Tissue nematodes Trichinella spiralis
Visceral larval migrant Toxocarca canis
Lung worms Angiostrongylus cantonensis

5. Parasitic Infection in
Immunocompromised Host
 Any parasitic infection in the mmunocompromised
host may cause more severe symptoms
 The body has three types of host defense
mechanisms: surface and mechanical factors, the
humoral immune system, and the cellular immune
system.
 Further distinction can be made as:
 First-line (nonspecific) innate immunity
 Second-line (specific) adaptive immunity

6.  A compromised host is one in whom normal defense
mechanisms are impaired (e.g., AIDS), absent (e.g.,
congenital deficiencies), or bypassed (e.g., penetration of
the skin barrier). These patients are becoming more
common in most medical facilities and represent a growing
problem in terms of diagnosis and subsequent therapy.
Parasitic Infection in
Immunocompromised Host

7. Host Defense Mechanisms

8. Host Defense Mechanisms

9. Parasitic Infection in Compromised Host
 Parasitic infections in individuals with a normal immune
system are not uncommon. Not only are they unpleasant and
debilitating, but they can be fatal.
 However, individuals with immune system defects have an
abnormally high susceptibility to infections with nonvirulent
and minimally pathogenic organisms.
 Compromised individuals are usually contract parasitic
infections in addition to suffering numerous infectious
episodes with bacterial, viral, and fungal organisms.

10. Parasitic Infection in Compromised Host
 Immune system deficiencies can be attributed to
 Congenital absence
 Abnormal development
 Malignancy
 Therapy with cytotoxic drugs
 Irradiation, or
 Infections, such as with HIV especially patients with
AIDS.

11. Entamoeba histolytica
 Entamoeba histolytica is the cause of amebiasis that shows
two significant clinical symptoms
 Intestinal diseases (confined to GIT)
 Extra-intestinal diseases (invasion of the mucosal lining of
the gastrointestinal tract, the organisms
having passed through the mucosal lining, entered the
bloodstream, and been carried to other body tissues,
particularly the liver)
 These differences should be understood when one is
discussing the clinical interpretation of serologic tests for
amebiasis.

12. Entamoeba histolytica
 Pathogenic E. histolytica can now
be differentiated from
nonpathogenic E. dispar using
immunoassays; morphologic
chracteristics are identical, E.
histolytica containg RBCs in the
trophozoite could be identified as
pathogenic true E. histolytica
Size:
 Trophozoite: usual range, 15–
20μm; range, 10– 60μm.
 Cyst: usual range, 12– 15μm, range,
8.5– 20μm

14. Parasitic infections: clinical findings in normal
and compromised host

15. Parasitic infections: clinical findings in normal
and compromised host

16. Parasitic infections: clinical findings in normal
and compromised host

17. Entamoeba histolytica
(Topleft) Entamoeba histolytica
trophozoites containing ingested RBCs.
(Down) Entamoeba histolytica/E. dispar
cysts. (Right) Amebic liver abscess in
section; note the “flaskshaped ” ulcer.

18. Free living amoeba: Naegleria fowleri
(Left) Flagellated form of Naegleria;
(Right) cyst of Naegleria, not seen in human
Naegleria fowleri trophozoite (note the
large karyosome within the nucleus)
N. fowleri trophozoites within
brain tissue.
N. fowleri trophozoites; note
globby/rounded ” pseudopods

19. Free living amoeba: Acanthamoeba
Acanthamoeba cysts in brain: case of GAE
Acanthamoeba trophozoite (note the
sharp, spiky pseudopodia; Acanthamoeba
cyst (note the
hexagonal double wall)
Acanthamoeba keratitis
Cutaneous Acanthamoeba infection

20. Toxoplasma gondii infections in
immunocompromised patients

21. Blastocystis sp. Central body forms,
Wheatley ’s trichrome stain.
Multiple Giardia trophozoites seen in
gastrointestinal tract
Toxoplasma gondii in bone marrow

22. Cryptosporidium infections in
immunocompromised patients
Cryptosporidium. Oocysts stained using the
modified acid-fast stain; note the spherical
shape. Oocysts measure 4 to 6 μm and some
contain sporozoites that are visible.

23. Cyclospora cayetanensis. (Top) Oocysts stained
using the modified acid-fast stain (note the
spherical shape; oocysts measure 8 to 10 μm;
some oocysts do not stain, thus the organisms
are said to be “modified acid-fast variable ”)
Cystoisospora (Isospora) belli. Wet
mounts; immature oocyst (contains single
sporoblast) on the left and mature oocyst
on the right

24. Sarcocystis sp. (Upper, left) Sporulated
oocyst in unstained wet mount; (right)
sporulated oocyst in a wet mount
viewed under UV microscopy.
Microsporidia. Microsporidial spores seen in
nasopharyngeal aspirate from AIDS patient;
note the horizontal or
diagonal lines (arrows) representing the
polar tubules within the spores, stained with
Ryan modified trichrome stain.
Leishmania spp

25. Strongyloides stercoralis. (Top) Rhabditiform
larvae seen in bronchoalveolar lavage fluid
specimen, Giemsa stain (larvae can also be
seen in sputum in heavy infections or in the
hyperinfection syndrome). (Middle) Larva
from sputum, Gram stain. (Bottom) Tracheal
aspirate containing many larvae

26. Differential characters of erythrocytic phase
26
P. vivax
P. falciparum
P. malariae
P. ovale

27. Differential characters of gametocytic phase
27
P. vivax P. falciparum
P. malariae P. ovale
Female
Male
Female
Male
Female
Male
Female
Male

28. Three examples of blood films containing the ringlike forms of Babesia spp. Various ring
forms, multiple rings per cell; some rings present outside of the red blood cells (circle);
note the typical image of the “Maltese cross ” configuration of the four rings (square). Note:
it is rare to see Plasmodium rings outside of the RBC

29. Scabies
mite
Hands of a homeless individual with
AIDS and severe scabies(crusted
scabies)