EYE PATHOGENS. Dr. WILLIAM J. BENJAMIN. Eye Physiology & Ocular Prosthetics Laboratory. School of Optometry

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1 CHLAMYDIAL & PARASITIC EYE PATHOGENS Dr. WILLIAM J. BENJAMIN Eye Physiology & Ocular Prosthetics Laboratory University of Alabama at Birmingham School of Optometry Presented at the UAB School of Optometry as Part of OPT 121: MICROBIOLOGY and IMMUNOLOGY November 23, 2009

2 RICKETTSIAE & CHLAMYDIA INTRACELLULAR PARASITES HAVE DNA AND RNA, UNLIKE VIRUSES REPLICATE INSIDE HOST CELL NOT VERY DEPENDENT ON HOST CELL MACHINERY LESS VIRULENT THAN MOST CELL-LYSING VIRUSES SUSCEPTIBLE TO MOST ANTIBACTERIALS DIFFERENCE IS LIKE SPLITTING HAIRS

3 VIRUS-LIKE BACTERIA OF SPECIAL SIGNIFICANCE RICKETTSIAE: Generally Require a Vector TYPHUS, carried by several vectors Q FEVER, pasteurization of milk ROCKY MOUNT N SPOTTED FEVER, tick CHLAMYDIA Chlamydia trachomatis: from humans Chlamydia psittaci: from birds TRACHOMA, AND NON-TRACHOMATOUS INCLUSION KERATOCONJUNCTIVITIS ACCOMPANIED BY GENITOURINARY TRACT INFECTION

4 MICROBIOLOGICAL DIAGNOSIS OF OCULAR CHLAMYDIAL INFECTIONS CLINICAL PRESENTATION OCULAR SURFACE CYTOLOGY POLYMORPHIC RESPONSE PMNs, Lymphocytes, Monocytes Leber Cell in Trachoma: Giant macrophages packed with phagocytized debris Eosinophil (?)

5 MICROBIOLOGICAL DIAGNOSIS OF OCULAR CHLAMYDIAL INFECTIONS STAINS: GIEMSA, FLUORESENT ANTIBODY INCLUSION BODIES: Cytoplasmic, visible with Light Microscopy TISSUE CULTURE: UNRELIABLE

6 TRANSMISSION OF CHLAMYDIA URETHRAL EPITHELIUM OF MEN AND CERVICAL EPITHELIUM OF WOMEN EYE INFECTION RARE W/O CONCURRENT GENITAL INFECTION ORAL ADMIN. OF ANTIBACTERIALS NECES- SARY: Tetracycline, Erythromycin THE PING PONG FACTOR

7 CLASSIFICATION OF PARASITES THAT INFECT OR INFEST THE HUMAN EYE INTRACELLULAR PARASITES Viruses Chlamydia Bartonella henselae (Parinaud s OGS) EXTRACELLULAR PARASITES ENDOPARASITES ECTOPARASITES

8 INTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Microsporidia: OVOID SPORE FORMERS TWO GROUPS for the EYE Nosema sp.: Cornea Stroma Ulcer Encephalitozoon sp.: Intractable Infiltrative Keratoconjunctivitis

9 INTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Microsporidia: NO ANTECEDENT TRAUMA VECTOR UNKNOWN ONLY IN THE IMMUNOCOMPROMISED BROLENE, FUMAGILLIN INHIBIT, BUT IN- FECTION RECURS AFTER CESSATION Spores in Stroma: Acid- Fast Stain, 1000x 3 Spores in Macrophage: EM

10 INTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Leishmania sp.: LEISHMANIASIS VECTOR: BITES OF SAND FLY, THEN INGESTED BY PMNs REPLICATION WITHIN PMNs, CAUSING LESIONS OF MUCOUS MEMBRANES, SKIN, AND VISCERAL ORGANS

11 INTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Leishmania sp.: LEISHMANIASIS OCULAR EFFECTS: EDEMA, ULCERS, SCARRING OF LIDS, CONJ., AND INTERSTITIAL KERATITIS

12 INTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Toxoplasma gondii: TOXOPLASMOSIS FECAL TRANS. BY DOGS, CATS, ETC. LOCALIZED CHOROIDAL GRANULOMA

13 INTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Toxoplasma gondii: TOXOPLASMOSIS FECAL TRANS. BY DOGS, CATS, ETC. LOCALIZED CHOROIDAL GRANULOMA

14 EXTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Onchocerca volvulus: ONCHOCERCHIASIS MICROFILARIAL NEMATODE (Worm) VECTOR: FEMALE BLACK FLY (Bites) Transfers microfilaria to humans Microfilaria enter body thru bites Wolbachia sp. Bacteria are essent- ial symbionts of nematodes

15 EXTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Onchocerca volvulus: ONCHOCERCHIASIS MICROFILARIA JOURNEY TO EYE via Ciliary Vessels, Nerves FLY ALSO DEPOSITS ITS EGGS NEAR RIVERS, LARVA GROW IN TROPICAL MOISTURE, i.e., RIVER BLINDNESS CORNEAL REACTION TO DEAD FILARIA AND WOHLBACHIA BACTERIA Mild / Early: Opacities Reversible Sclerosing Keratitis (1): Irreversible Scars SUSCEPTIBLE TO ANTIBACTERIALS

16 EXTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Trypanosoma rhodesiense & cruzi: KERA IS AFR. & SO. AMER. SLEEPING SICKNESS Acanthamoeba sp. UBIQUITOUS; 15 DIFFERENT SPECIES FREE-LIVING: NOT REALLY PARASITE

17 EXTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Acanthamoeba sp. BREATHING OF DUST, CONT- AM. WATER SWIMMING, HOT TUBS, TAP WATER CNS INFECTIONS via NASO- PHARYNYX, as with Naegleria

18 EXTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE A th b Acanthamoeba sp. TROPHOZOOITE & CYST FORMS

19 EXTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Acanthamoeba sp. FEEDS ON BACTERIA, FUNGI, -ZOA HUMANS & ANIMALS HAVE IMMUNITY CULTURED FROM NASOPHARYNX OF ASYMPTOMATIC ADULTS LEGIONNAIRE S DISEASE: AC, Humid.

20 EXTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Acanthamoeba sp. SITES OF OCULAR INFECTION Cornea, Orbit, Retina, Optic Nerve INITIAL KERATITIS CAN BE Herpes-like

21 EXTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Acanthamoeba sp. FACTORS IN INITIAL EYE INFECTION Antecedent Trauma Immunocompromise Repeated Exposure Exposure to Virulent Strain Inoculation of Immunoprivileged Site Wear of Soft Contact Lenses HIGHER INCIDENCE FOLLOWING FLOODS and HURRICANES

22 EXTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Acanthamoeba sp. DIAGNOSIS: CALCIFLUOR WHITE STAIN Fluorescent Microscopy; Stain Cysts

23 EXTRACELLULAR PROTOZOA THAT INFECT THE HUMAN EYE Acanthamoeba Sp. TREATMENT WITH MULTIPLE AGENTS Brolene, Antifungals Neomycin, Polymyxin B TREATMENT IS PROLONGED / YEAR ENCYSTMENT IS A PROBLEM CORNEAL TRANSPLANT OFTEN REQ. TOO MANY ENUCLEATIONS

24 ENDOPARASITES THAT INFEST THE HUMAN EYE THESE ARE A GROUP OF SOME 15+ PARA- SITES ASSOCIATED WITH THE GASTRO- INTESTINAL TRACT THEY ARE LARGER MULTICELLED ORGAN- ISMS, PERHAPS ON THE FRINGE OF BEING MICRO ORGANISMS ORGANISMS THEY SPREAD TO HUMANS BY: BITES OF FLIES, BUGS, MOSQUITOES FECALLY INGESTION OF UNDERCOOKED FOOD OR IMPURE WATER

25 ENDOPARASITES THAT INFEST THE HUMAN EYE Loa Loa: LOIASIS FILARIAL EYEWORM VECTOR: BITE OF MANGO FLY Chrysops allows microfilaria into body AROUND ORBIT & UNDER CONJUNCTIVA

26 ENDOPARASITES THAT INFEST THE HUMAN EYE Thelazia Sp. EYEWORM OF DEER, RABBIT HOOKWORM OF DOG, CAT VECTOR TO MAN: BITE OF FLY DIRECT SKIN PENETRATION BY LARVA

27 ENDOPARASITES THAT INFEST THE HUMAN EYE Toxocara canis & cati: TOXOCARIASIS DOG & CAT NEMATODE (ROUNDWORMS) FECAL TRANSMISSION OF EGGS TO HUMANS

28 ENDOPARASITES THAT INFEST THE HUMAN EYE Toxocara canis & cati: TOXOCARIASIS CHORIORETINITIS: Allergic Rxn to Worm

29 ENDOPARASITES THAT INFEST THE HUMAN EYE Trichinella spiralis: TRICHINOSIS LARVA ENCYST IN SKELETAL MUSCLE PIGS, HORSE, WALRUS, BEAR VECTOR TO MAN: INGESTION OF UNDERCOOKED MEAT EXTRA-OCULAR MUSCLES The only striated muscles of the Eye

30 ECTOPARASITES THAT INFEST THE HUMAN EYE Demodex folliculorum & brevis HAIR FOLLICLE & SABACEOUS GLAND NORMAL MITES OF LIDS, NOSE MAY BE VECTORS FOR OTHER M.O. s ROLE IN BLEPHARITIS UNCLEAR OVERGROWTH CALLED DEMODICOSIS

31 ECTOPARASITES THAT INFEST THE HUMAN EYE TICKS: Can Attach to Lid or Conjunctiva BLOOD-SUCKING ARTHROPODS VECTORS FOR RICKETTSIAE, VIRUSES LYME DISEASE: SPIROCHETE Borrelia burgdorferi & DEER TICK Deer Tick

32 ECTOPARASITES THAT INFEST THE HUMAN EYE Phthirus pubis: CRAB LOUSE & EGGS LOUSE & NITS IN PUBIC AREA, LASHES OCULAR EFFECTS: Blepharitis Madarosis Keratitis Bite Site

33 ECTOPARASITES THAT INFEST THE HUMAN EYE Phthirus pubis: CRAB LOUSE & EGGS TRANSMITTED BY BED SHEETS, CLOTH- ING, TOWELS, CLOSE CONTACT 1 OF 3 LICE TO INFEST HUMANS: Pediculus humanus corporis Pediculus humanus capitus

34 ECTOPARASITES THAT INFEST THE HUMAN EYE Sarcoptes scabei UBIQUITOUS HUMAN SCABIES MITE MITES BURROW INTO SKIN OF EYELID SPREAD BY BED SHEETS, CLOTHING, TOWELS, CLOSE CONTACT INFESTATION CALLED SCABIES, OR ACARIASIS

35 SUMMARY OF ANIMATE VECTORS ARTHROPODS FLEAS: Bubonic Plague FLIES: African Sleeping Sickness LICE MITES MOSQUITOES: Malaria TICKS: Tularemia, Lyme Disease MAMMALS DOGS, CATS, ETC. HUMANS

36 SUMMARY OF INANIMATE VECTORS FOOD & WATER BODILY LIQUIDS: TEAR FLUID (?) FECES CONTAMINATED OBJECTS (FOMITES)