Pathogen Table
- 1. Pathogen Disease Caused/Symptoms Diagnosis Treatment F U N G I Filamentous Fungi Microsporum Canis, Trichophyton Rubum, Epidermophyton Floccosum Infects keratinous tissues of hair, nails and skin. Only contagious mycosis from humans/animals Clinical scraping for microscopy and culture Clotrimazole, terbinafine Aspergillus Fumigatus (ubiquitous spores) Asthma, aspergillioma (fungal ball), invasive aspergillosis Systemic: lung, renal, cerebral (immunocompromised) Sinusitis, endocarditis IV Amphoteracin B, po Itraconazole or voriconazole Yeast-like (mainly grow as yeasts, but can grow in elongated forms or pseudomycelia) Candida albicans (opportunistic pathogen), C. tropicalis, C. glabrata Oral and vaginal candidiasis (thrush), candidaemia/ endocarditis, UTI Predisposed by: diabetes, trauma, steroids, surgery Wet prep. For Candida, swabs e.g. mouth, vagina, blood cultures in candidaemia IV Amphotericin B (candidaemia – systemic) Imidazole (mouth and vaginal infections) True Yeast Cyptococcus Nefomans (encironmental organism, opportunistic) Meningitis in HIV Cancer patients, pulmonary disease Disseminated Clinical suspicions Microscopy: India ink stain on CSF Culture: CSF, blood Antigen detection: CSF, blood IV Amphoteracin B, +/- flucytosine Difficult to eradicate Po fluconazole maintenance to prevent relapse Atypical fungus, previously classified as protozoan Pneumocystis Jiroveci (carinii, opportunistic) AIDS defining illness Seen in malignancy e.g. Hodgkins lymphoma Causes pneumonia – can be fatal Microcopy/cytology of bronchoalveolar lavage specimens Co-trimoxazole, pentamidine Dimorphic Fungi Histoplasma capsulatum – yeast in tissues, mould in environment Asymptomatic, acute/chronic respiratory infection, disseminated diease (liver, lungs, spleen, esp in HIV) IV Amphoteracin B Blastomyces Dermatiditis RTI, skin infection IV Amphoteracin B Coccidiodes Immitis RTI, systemic infection IV Amphoteracin B Paracoccidiodes brasiliensis Skin and mucosal granuloma IV Amphoteracin B
- 2. P R O T O Z O A N Sporozoa Plasmodium Falciparum (malignant tertian malaria) P.vivax and P.ovale (benign tertian malaria) P.malariae (quartan malaria) Influenza-like, diarrhea and vomiting, headache, arthralgia (joints), confusion, fits, respiratory distress P.vivax: chloroquine followed by primaquine P.falciparum: quinine (600mg), followed by doxycycline Flagellates Giardia Lamblia (spread person-person or via water borne cysts) Diarrhoea, malabsorption, partial villous atrophy, trophozoites attach to small bowel mucosa Metronidazole Leishmania donovani, L.tropica, L.braziliensis (sandfly = host) (LEISHMANIASIS) Cutaneous, mucocutaneous and visceral clinical presentations Amoebae Entamoeba Histolytica (spread person-person or water borne cysts, trophozoites emerge in small bowel and invade large bowel) (AMOEBISASIS) Amoebic dysentery (diarrhoea + blood), liver abscess via spread through portal vein Fresh stool, colon biopsy Serum: amoebic fluorescent antibody test Metronidazole (trophozoites) Diloxanide (cysts) Coccidia Toxoplasma Gondii (cat, other animals, rodents, bird and man = host) (TOXOPLASMOSIS) Asymptomatic, tissue encystation which results in reactivation in immunocompromised hosts; lymphadenopathy Lymphadenopathy - biopsy Brain - MRI/CT scan + biopsy Organ involvement (serology) Only for organ associated or sever systemic disease Sulfadiazine + pyrimethamine H E L M I N T H S Nematodes (roundworms) Filariae (vectors – mosquitoes and other insects) Wuchereia bancrofti Brugia timori/malayi Loa loa (FILARIASES) Adult worms reside in lymphatics or tissues > tissue inflammation, fibrosis Adult female releases microfilariae which circulate the blood and tissues > eosinophilia Trematodes (flukes) S.haematobium, S.mansoni, S.japonicum (SCHITOSOMIASIS) S.mansoni: blood-stained diarrohea, rectal ulceration and fibrosis, hepatic fibrosis and portal hypertension S.haematobium: painless, terminal haematuria, recurrent UTI, renal failure 4weeks: allergic reaction, fever, rash… 3months: asymptomatic egg deposition Serology: ELISA Supports parasitological diagnosis Praziquantal (90% curative) Cestodes (tapeworms) Taenia solium (pork), Taenia saginatum (beef), Diphyllobothrium latum (fish), Echinococcus (dog) – E.granulosus Hydatid disease (ECHINOCOCOCCOSIS) Man: acquired by ingestion of cysts from contact with, or food/water contaminated with dog excreta Liver (60%), lung (20%), rupture of liver cyst >> multiple peritoneal cyst Eosinophilia, +ve hyatid CFT, US & CT scans Albendazole and surgery