Book1 by liuqingyan

VIEWS: 4 PAGES: 5

									         Pathogen                          Herpes Simplex Virus                                      Dengue Virus                                                  Varicella-zoster Virus                                Measles Virus
Modes of transmission (How Direct contact by inocculation of infected                                                                                Aerosolized respiratory secretions, contact             Inhalation of airborne droplets from
                           secretions/body fluids to a susceptible mucosal site.  Mosquitos
 & where did the patient                                                                                                                             w/ruptured vesicles and reactivation from dorsal        nasopharyngeal secretions of or direct
                           Frequent sexual transmission. Vertical transmission to Warm humid environment-Southwestern U.S
  acquire the infection?)                                                                                                                            root ganglion                                           contact with infected persons
                           fetus also occurs
                             Latency and absent or minimal signs or symptoms.                                                                                                                                Hemagglutinin glycoprotein binding to
 Virulence and pathogenicity                                                       Direct and indirect mechanisms. Flavivirus, Dengue Types          Double-stranded linear DNA, enveloped, and
                             Signs might show as one or more blisters on or around                                                                                                                           RBCs and upper respiratory cells.
       of the organism                                                             I,II,III, IV                                                      icosohedral symmetry
                             the genitals/ rectum or lips.                                                                                                                                                   Fusion protein.

                                                                                             Encephalitis/ Encephalopathy                            Virus migrates along sensory nerves & produces
CNS pathology caused by this Infants - encephalitis, recurrent aseptic meningitis                                                                                                                       Subacute sclerosing panencephalitis
                                                                                             Intracranial hemorrhage                                 sensory loss, pain, other neuro complications. May
         organism            Adults - severe sporadic fatal encephalitis                                                                                                                                (SSPE) many years after infection
                                                                                             Cerebral swelling                                       cause encephalitis
                                                                                             High fever
 Clinical manifestations and      Main Symptoms: Vesicles on the lips and mouth, on the      Rash                                                    2 week incubation followed by fever & headache          High fever and Koplik's spots. SSPE
 presenting symptoms (How         genitalia of the patient                                   Bone and joint pain                                     development. A rash on trunk & face then spreads        = slowly progressing mental
 would the patient present to     Other Possible Symptoms: fever, common viral               Backache                                                to entire body; vesicles rupture & scab; patients are   deterioration, incoordination, behavioral
       you in the clinic?)        symptoms                                                   Headaches                                               infectious until all of lesions scab over.              changes, and myoclonus
                                                                                             Symptom free for days then a high fever and new rash
                                                                                             Purkinje cells
                                                                                             Astrocytes                                                                                                      Entire brain but more severe in
Region(s) of the CNS attacked                                                                Choroid plexus                                          Remains dormant in the trigeminal & dorsal root
                              Brain - meninges, olfactory and trigeminal tracts                                                                                                                              neocortex, white matter, hippocampus,
      by this organism                                                                       Cerebral cortex                                         ganglia where it can reactivate later in life
                                                                                                                                                                                                             thalamus, and ventral brainstem.
                                                                                             Microglia

                                                                                          Virus cultures/ serology
                                   Tzanck prep shows multinucleated large cells &
                                                                                          Hemorrhagic manifestations                                 Vesicles are described as dew drops on top of a         Antibody titer for measles virus.
     Methods of diagnosis          intranuclear inclusion bodies. PCR, ELISA, & Direct
                                                                                          Platelet count of less than 100,000 per mm3                rose petal: a red base w/fluid filled vesicle on top.   Characteristic periodic activity on EEG.
(List at least 2 diagnostic tests) Fluorescent Antibodies (DFA) tests from biopsy of skin
                                                                                          Plasma leakage                                             Tzanck prep reveals multinucleated giant cells          MRI
                                   lesions


                                  Immunocompromised patients (AIDS, transplant
                                                                                                                                                                                                             Pneumonia, eye damage, myocarditis,
  Possible complications of       recipients, chemotheropathy, malnutrition, burns) may      Actue Disseminated Encephalomyelitis (ADEM) and shock   Pneumonia or encephalitis can occur in
                                                                                                                                                                                                             encephalitis, 20% fatal death in early
          infection               develop extensive mucocutaneous infections, or                                                                     immunocompromised patients
                                                                                                                                                                                                             pregnancy
                                  disseminate infection to organs (liver, lung, GI tract).

                                                                                        Supportive
                              Anti-virals such as Acyclovir, Valacyclovir, Famciclovir,                                                              Acyclovir is the drug of choice. Other drug options
Treatment (Drug of choice and                                                           Rest and fluid intake (hydration)                                                                                MMR vaccine, antipyretics for fevers
                              Trifluridine eye drops (for corneal infection). Infection                                                              are Valacyclovir & Famciclovir. Immunization with
        alternative)                                                                    Avoid aspirin & NSAIDS                                                                                           such as acetaminophen
                              prevention through condom use                                                                                          Chickenpox vaccine or Zoster immune globulin
                                                                                        Tylenol and Codeine for severe headches and pain
                              Acyclovir is contraindicated in impaired renal/liver                                                                   Acyclovir- nausea, vomiting, diarrhea, or headache.
Possible adverse reactions to function. May cause seizures, coma & leukopenia                                                                        Famciclovir-confusion, dizziness, insomnia, &       Rare complications include joint pain,
                                                                                             None
         treatments           Valacyclovir may cause renal failure, anemia,                                                                          hallucinations. Vaccine- soreness, fever, rash, &   mild rash & fever
                              psychosis, thrombocytopenia                                                                                            seizure
                                                                                                                                                     Isolated paralysis of occulomotor muscles has
                                  Latent virus reactivated by stress, menstruation,                                                                                                                          Inclusion bodies in oligodendrocytes,
    Unique features of CNS                                                                                                                           been noted. Less common is encephalitis,
                                  anxiety, fever, sunlight, & immunocompromise. Can          Fatal in less than 1% of cases.                                                                                 neurons, and astrocytes; chronic
  infection by this pathogen                                                                                                                         meningitis, cerebella ataxia, and Guillain-Bare
                                  cross the blood-placenta barrier.                                                                                                                                          inflammatory reaction
                                                                                                                                                     Syndrome.

Specific high risk conditions or                                                                                                                     Most serious with immuno-compromised
                                 Etiology: HSV-1 and HSV-2
   patient population (ie.                                                               Pre-existing anti-dengue antibody                           individuals (particularly leukemic children.) Also,
                                 Viral shedding can occur even when no herpetic lesions                                                                                                                  Non-vaccinated individuals
  pregnancy, diabetes, HIV,                                                              Caucasians at greater risk                                  the virus can cross placenta and cause congenital
                                 are visable, usually spread days before outbreak occurs
             infant)                                                                                                                                 infections in the fetus.
             Cytomegalovirus                                    Rabies Virus                                 Mycobacterium tuberculosis                                   Neisseria meningitidis                          Group B Streptococcus
                                                                                           It is primarily a pulmonary disease that is initiated by the
                                                Found in the saliva of infected animals;
Droplet (respiratory), Urine, Dairy products,                                              deposition of the pathogen, contained in aerosol droplets, onto     Respiratory droplets                             Sexual activity, male to female oral, male
                                                virus can be inhaled in dust from bat
Tears, Stool , Sexual contact (rare)                                                       lung alveolar surfaces. May affect bone, CNS, and other organ       Infected secretions                              rectal. Vertical transmission to neonates
                                                guano.
                                                                                           systems.
40-100% adults seropositive in Europe,                                                                                                                                                                          Virulence significant by Capsular
                                                                                           Rich lipid cell wall is likely responsible for the resistance and is a Endotoxin, polysaccharide capsule, fimbriae
Australia & USA. Highest rates occur in         Fatal if left untreated.                                                                                                                                        polysaccharide, murine model of infection,
                                                                                           key virulence factor. May be dormant.Has long generation time. IgA1 protease
Africa & SE Asia.                                                                                                                                                                                               Beta-Hemolysin expression

                                                                                           Infection starts in a subpial or subependymal cortical focus,    Organism passes through epithelial cells in
Uveitis or retinitis, sensorineural hearing     Acute encephalitis; leads to either
                                                                                           resulting in a granuloma that erodes into subarachnoid space, to pharynx & multiply to produce bacteremia.           Meningitis, Coma, Septic Shock
loss, residual neurological damage              hyperactivity or paralytic syndromes.
                                                                                           cause basal leptomeningitis.                                     Localizes in CSF

"Mononucleosis" like; mild pharyngitis                                                                                                                                                                         Lethargy, poor feeding (neonates), jaundice
                                                Symptoms include headache, fever, pain,                                                                        Fever & leukocytosis, H/A, lethargy, confusion,
(without exudate); variable lymphadenopathy                                                Malaise, intermittent headache, and low-grade fever, followed                                                       abnormal temperature, grunting respirations,
                                                uncontrolled movements, inability to                                                                           irritability, stiff neck, purpura, petichiae
and splenomegaly; retinitis in AIDS patients;                                              within 2-3 weeks by protracted headache, vomiting, confusion,                                                       pallor, hypotension, dementia, alterations in
                                                swallow water, paralysis, mania, lethargy,                                                                     Preceeding sore throat
pneumonia in setting of immune                                                             meningismus, and focal neurological signs.                                                                          mental status, paraplegia/quadriplegia, UTI
                                                coma, death.                                                                                                   Onset from 1-7 days
suppression.                                                                                                                                                                                                   and endomtritis in females


                                                                                                                                                               CSF
                                                                                                                                                                                                                Meningitis, disruption of anatomic barrier
                                                Rabies virus traces peripheral nerves from Tuberculosis meningitis preferentially involves the meninges        Leptomeninges
Ependymal cells                                                                                                                                                                                                 protecting the brain in consequence of
                                                bite location to spinal cord to brain.     and basal cisterns of the brain and spinal cord.                    Cranial nerves
                                                                                                                                                                                                                surgery or chronic sinusitis
                                                                                                                                                               Cerebral tissue


Viral culture (blood, CSF, urine, tissue).      Fluorescent antibody detection of rabies MRI with gadolinium is preferred method for detecting the extent LP for CSF microscopy
                                                                                                                                                                                                                Isolation culture from Blood or CSF, Gram
Direct viral microscopy                         viral antigens on skin; viral culture or PCR of leptomeningeal disease. CSF analysis to detect decreased Culture of nasopharyngeal swab
                                                                                                                                                                                                                stains of vaginal/cervical swabs, PCR Assay.
Serology.                                       of brain biopsy post mortem.                 glucose level, elevated protein levels, & a slight pleocytosis. Blood culture



Sensorineural hearing loss, Residual                                                       Primary complications include communicating hydrocephalus,
                                                Complications include paralysis, mania,                                                                        Fatal sepsis, Hearing loss, mental retardation, Pelvic abscess, septic thrombophlebitis, rapid
neurological damage including epilepsy in                                                  vasculitis with resulting infarction, and ventriculitis. Cavitary
                                                lethargy, coma, and death                                                                                      loss of limbs, & Seizures                       valve destruction, arthritis, deafness, death.
infants                                                                                    lesions, spread to susceptible persons, drug resistance.


Most cases self-limited. Adults, Ganciclovir,                                              Respiratory isolation.                                              Ampicillin +/-
                                              Vaccination may prevent further                                                                                                                                   Ampicillin is the drug of choice. Ceftriaxone &
Adefovir                                                                                   Typical meningeal infection is treated with Isoniazid, Rifampin,    Clavulanate
                                              symptoms; post-exposure prophylaxis.                                                                                                                              Vancomycin may also be used
Pediatric, Ganciclovir                                                                     Pyrazinamide, Streptomycin, Ethambutol.                             Ceftriaxone

                                                                                           Drug induced hepatitis; Thrombocytopaenia, fever and itching
Hematological toxicity, hearing loss in                                                                                                                        Ampicillin, clavulanate: allergies               Red Man Syndrome, othotoxicity,
                                                No possible adverse reactions.             from Rifampin, Neuropathy from Isonizid, Rashes from
children                                                                                                                                                       Ceftriaxone: disulfiram reaction with alcohol    nephrotoxicity
                                                                                           Pyrazinamide.


                                                                                           Infection of the brain parenchyma and spinal cord also occurs       Cross BBB causing an inflammatory response Meningitis uncommon in adults unless
                                                20% of patients demonstrate Negri bodies
Possible link in etiology of malignancy                                                    and can result in tuberculous granulomas, tuberculous               in sub arachnoid space                     following a cranial surgery, frequent
                                                (inclusion bodies) on brain tissue sample.
                                                                                           abscesses, or cerebritis.                                           Can extract iron from transferrin          connection to urinary tract infections


                                                                                         TBM is more common in patients who are immunosuppressed, Students in primary or secondary schools &
HIV, immunocompromised, pregnancy,              High risk situations include exposure to                                                                                                                        Neonates, elderly, neurosurgery patients,
                                                                                         such as older persons, young children, patients with HIV or college dorms
infants (congenital)                            rabid animals and exposure to bat guano                                                                                                                         diabetes, cancer HIV.
                                                                                         diabetes, and patients taking steroids or cytotoxic drugs.  75% cases present before 15yo
          Treponema pallidum (syphilis)                                  Borrelia burgdorferi                                  Coccidioides immitis (coccidioidomycosis)                                 Cryptococcus neoformans
Sexually Transmitted Disease
                                                                                                                   Fungus found in alkaline (arid) soil. Mycelia survive in rodent burrows.
Enters body through intact mucous membrane or                                                                                                                                               Found in nature: soil & pigeon droppings.
                                                      Tick bite (Ixodes, Amblyomma)                                Conedia dispersed by wind - contracted by contact with flora, rodents,
epithelial abrasions                                                                                                                                                                        Transmission: inhalation of yeast into the lungs.
                                                                                                                   soil, & bat guano. Rarely transmitted by animal bite & organ transplant

Additional phospholipid layer,                                                                                     Most virulent fungal pathogen but 60% asymptomatic. Infection only
                                                      VlsE surface protein capable of variance and evasion of
Axial flagella under sheath                                                                                        occurs via direct contact with the fungus (inhalation of airborne conidia) Low (may vary with immunosuppression)
                                                      immune system
                                                                                                                   – not spread person to person
Can attack blood vessels in brain and meninges;       Meningitis, cranial neuritis, motor or sensory
nerve tissue infarct. Can affect spinal cord. Can                                                                  CNS infection of the meninges is a possible area of infection – spreads
                                                      radiculoneuritis, encephalitis, cerebellar ataxia,                                                                                   Meningoencephalitis
damage nerve cells of brain                                                                                        from lungs
                                                      pseudotumor


Rash on Palms, Condyloma Latum,                                                                                    40% symptomatic: flu-like illness, cough, headache, CP, nonpruritic fine   Usually asymptomatic. Meningitis may cause
                                                      Low-grade fever, fatigue, headache, conjunctivitis, myalgia,
Gummas of Skin, Aneurism,                                                                                          papular rash, muscle ache, dyspnea, weight loss. Most make full            headache, N/V, fever, confusion, ataxia, cranial
                                                      and arthralgia. Typical rash of erythema migrans (75% of
Neurosyphilis                                                                                                      recovery in weeks to months, but chronic infection possible. Suspect if    nerve deficit, cerebral edema & resulting brainstem
                                                      cases)
                                                                                                                   recent travel to SW US, Mexico, & South America                            compression; pneumonia, skin ulcers, bone lesions.


Blood vessels in brain, meninges
Nerve tissue of brain
                                                      Blood brain barrier Astrocytes                               Colonizes the meninges                                                     Meninges
Spinal Cord




VDRL, RPR                                                                                                          Serological testing of blood or body fluid to look for anti-fungal         Lumbar Puncture (shows yeast cells) or
                                                      Serology (ELISA and Western blot test). Nucleic acid
FTA-ABS                                                                                                            antibodies. Biopsy of affected tissue under a microscope to look for       Cryptococcal Antigen Test (detects cryptococcal
                                                      amplification
                                                                                                                   fungus. Culture of tissue or body fluids                                   polysaccharide antigens)



Mental Deterioration                                  Neurological disease (Bell's palsy, Parsonage-Turner         A small number of people develop chronic pulmonary infection or
                                                                                                                                                                                              Chronic lymphocitic meningitis, or pneumonia in
Psychiatric Symptoms                                  syndrome, Guillain-Barre and Bannarth syndrome); Joint       disseminated infection. Infection outside the lungs can affect CNS,
                                                                                                                                                                                              immunosuppressed patient (the 2 main problems)
                                                      involvement; Cardiac disease                                 cause skin lesions & possibly bone and joint infections.

                                                                                                                   Sometimes resolves spontaneously. Fluconazole for uncomplicated            Non-meningeal: Fluconazole.        Meningeal:
DOC: Penicillin                                                                                                    cases. Complicated infections always require treatment. 2nd line           Fluconazole or Amphotericin B. AIDS Pts:
Alt: Erythromycin                                     Doxycycline is the drug of choice. Ceftriaxone is 2nd line   alternative is ketoconazole.                                               Amphotericin B & Flucytosine; followed by
                                                                                                                                                                                              Fluconazole.

                                                      Acidosis, allergy, anemia, anosmia, diarrhea, drug-induced                                                                              Fluconazole - drug interactions     Amphoterici B -
                                                                                                                 Fluconazole can cause cardiac arrhythmias and in some cases is
Allergic Reaction                                     lupus, dysosmia, erythema multiforme, esophageal                                                                                        nephro toxicity     Flucytosine - hematologic
                                                                                                                 hepatotoxic, do not use in breastfeeding mothers
                                                      ulceration                                                                                                                              toxicity


Ataxia from spinal cord disruption, General paresis                                                                Spreads only through direct contact with fungus – infectious particles
                                                                                                                                                                                              It only effects the meninges, but leads to
of the insane, meningitis                             Bilateral Bell's palsy Bannwarth's syndrome                  becomes airborne through disturbance of soil. Route of exposure is
                                                                                                                                                                                              encephalopathy.
                                                                                                                   usually by inhalation.


People having unprotected sex, high risk sexual
                                                                                                                 Increased risk for developing disseminated infection in people of African-
behavior,                                             Pregnancy (risk of miscarriage). Individuals spending time                                                                            75% of cases occur in immuno-suppressed persons.
                                                                                                                 American, Asian, or Filipino descent; pregnant women in 3r trimester, &
intravenous drug users                                outdoors in endemic areas                                                                                                             10% of AIDS patients develop the disease
                                                                                                                 in immunocompromised persons.
                  Histoplasma capsulatum                                          Candida albicans                                            Naegleria fowleri                                              Plasmodium falciparum
Found in soil contaminated with mold form. Transmission by
                                                                                                                       Naegleria fowleri is found worldwide in soil, sewage, heating
inhalation of aerosolized of conidia & mycelial fragments.       Normal flora of the human GI tract. Spread of
                                                                                                                       and ventilation units, swimming pools, power plant discharges,     Transmitted by female Anopheles mosquito.
Fragments deposit in alveoli where they undergo                  pathogenic form via direct human to human contact
                                                                                                                       river, coastal and lake water, and thermally polluted water.
transformation from mold to yeast
Virulence associated with cell surface proteins. HSP60 aids in   Transforms to pathogenic multicellular filamentous
                                                                                                                       Enters via inhalation or splashed onto the olfactory epithelium.
attachment to host macrophages, YPS3 participates in             form, usually during immunocompromise. Can                                                                             Responsible for 80% of all infections and 90% of all deaths
                                                                                                                       The cells of the olfactory are capable of phagocytosis, and this
dissemination to extrapulmonary sites, & α-glucan assists in     involve any organ/system; pathogenesis occurs by                                                                       related to malaria
                                                                                                                       is the mechanism by which the amebas invade the body.
phagocytic uptake                                                TLR2, TLR4, & TLR9 signaling
Granulomatous basilar meningitis, vascular inflammation,                                                               Enters the CNS via the nasal cavity, moving along the nerve
perinerual inflammatory changes in cranial nerves. Many H.                                                             fibers through the floor of the cranium via cribriform plate and   Lysis of red blood cells blocks venules and causes cerebral
                                                                 Fungal meningitis
capsulatum at periphery of mass lesions. Coin-like lesions on                                                          into the brain. There it becomes pathogenic causing primary        infarcts leading to seizures and comas.
histocytes & reticuloendothelial cells                                                                                 amoebic meningoencephalitis.
Regional lymphadenopathy, cutaneous & Subcutaneous
                                                                                                                       Headache, fever, N/V, & stiff neck. Causes destruction of brain
lesions (papules, nodules, abscesses, ulcers), flu-like          Headaches, stiff neck, & irritability. Symptoms are
                                                                                                                       tissue leading to confusion, lack of attention to people and    Recurrent fevers, shaking chills and soaking sweats in a 36 to
symptoms (malaise, fever, chest pain, dry cough, headache,       less severe and onset more gradual than bacterial
                                                                                                                       surroundings, ataxia, seizures & hallucinations. The disease    48 hour cycle. Hepatomegaly, Splenomegaly
loss of appetite, joint/muscle pain, chills), night sweats, &    meningitis
                                                                                                                       progresses rapidly & can result in death within 2-7 days.
dyspnea


                                                                                                                       Edematious cerebral hemispheres, uncal & tonsillar hernias,
Meninges                                                         Parenchymal brain tissue & meninges                   congested arachnoid-->Changes throughout hemispheres, brain venules of the brain
                                                                                                                       stem, cerebellum and upper portion of spinal cord


Culture growth from tissue or body fluid sample (i.e. CSF,                                                             Examine CSF under light microscope for organism. Cultured of
                                                             LP shows CSF pleocytosis, hypoglycorrhachia, &
blood, bone marrow, liver tissue, skin, or mucosal lesions).                                                           CSF or brain tissue for definitive diagnosis. Retrospective
                                                             elevated protein. Stains with KOH & silver. Blood                                                                        examination of blood smears and rapid antigen diagnostic tests
Detection of histoplasma antigen in the CSF. Immunodiffusion                                                           diagnosis by examining paraffin-embedded brain tissue sections
                                                             assay for beta-D-glucan
test, looking for H bands                                                                                              stained with hematoxylin & eosin.


Pericarditis, Pleural effusion, Chronic pulmonary                                                                      Primary amebic meningoencephalitis
histoplasmosis, Progressive disseminated histoplasmosis,                                                               Headache, fever, nausea, vomiting, stiff neck, brain tissue
                                                           Brain abscesses, ventriculitis, & hydrocephalus                                                                                Death, Coma, seizures, impaired consciousnes.
Progressive pulmonary fibrosis, Osseous lesions,                                                                       destruction, confusion, lack of attention, loss of balance,
Osteomyelitis, Meningitis, Non-communicating hydrocephalus                                                             seizures and hallucinations, coma and death


Amphotericin B, Ketoconazole, Fluconazole, Flucytosine (in       Amphotericin B is the drug of choice, Fluconazole 2nd                                                                    Chorloquinine, if not resistant. Quinine, artemeter, or mefloquine
                                                                                                                       Supportive care; No FDA approved drug.
combination)                                                     line                                                                                                                     if resistant to chloroquinone.



Skin rash, Hepatotoxicity, Nausea, Vomiting, Diarrhea,           Amphotericin B-nephrotoxicity       Fluconazole-                                                                         All cause GI upset and hemolysis in individuals with G-6-P-D
                                                                                                                       No drugs approved for this disease.
Hematopoietic depression (rare)                                  hepatoxicity, skin rash, nausea, vomiting, diarrhea                                                                      deficiency.


Can cause meningitis, single or multiple stroke syndromes, &
                                                                                                                    Enters the body through the nasal cavity and causes primary
encephalitis. This can create chronic headache, confusion, a     Rarely causes meningitis & disease develops slowly                                                                       Even with treatment 15-20% of people who develop cerebral
                                                                                                                    amebic meningoencephalitis.
decreased level of consciousness, seizures, & deficits of the    making diagnosis difficult                                                                                               malaria will die.
                                                                                                                    Destroys brain tissue and leads to death.
cranial nerves.

                                                                 Immunocompromised patients, prior surgery,
HIV+ & other Immunocompromised patients, infants < 1 year        antibiotic therapy, malignancy, diabetes, burns,      The disease usually occurs in children and young adults in good Children under the age of 5 have the highest mortality rate with
of age, & the elderly                                            neutropenia, intravenous catheters, injecting drug    health who have recently swum in warm water.                    malaria infection.
                                                                 abuse
                        Toxoplasma gondii                                   Taenia solium                            (Pig Tape Worm)
                                                                       Adults occur in human GI tract (definative host) - fecal-oral spread of
Ingestion of feces from infected cats, aquired congenitally, and
                                                                       ova to pigs (intermediate host). GI tapeworm infection by ingestion of
other vectors for oocysts ingestion (ie. Food by flies and
                                                                       undercooked pork. CNS infection by larvae via fecal-oral ingestion of
cockroaches)
                                                                       eggs from person with classic GI infection
Intracellular parasite with receptors consisting of laminin, lectin,
and SAG1 allow for attachment and penetration. No external             Based on exposure & distribution of cysts. Avg. time to onset of S/S
changes occur in host cell and tachyzoite multiplication leads to      is 5 yrs. Adults produce >40K eggs/day which survive months in soil.
rupture of cell and dissemination. Able to cross placenta
In fetus: encephalomyelitis - may lead to neonatal death.              Varies based on number/size/location of lesions. Cysts outside CNS
Immunodeficient: encephalitis, meningoenephalitis, CNS lesions,        often asymptomatic. Increased ICP if cyst obstructs CSF flow. Ocular
and necrotizing retinitis                                              cysts cause blindness. Cyst death causes massive inflammation


Subacute onset of hemiparesis, seizures, mental status and visual Typically latent for 5 yrs. commonly followed by onset of seizures &
changes. Focal neurological abnormailities, cranial nerve lesions, headaches. Sequelae may include hydrocephalus, altered LOC, focal
neuropsychiatric symptoms.                                         neuro deficit, & aseptic meningitis.




                                                                       Cysticerci may occur anywhere in the body but show preference for
cerebrum, brainstem, and spinal cord
                                                                       CNS (brain, spinal cord, eye) & skeletal muscle



                                                                       Dx by CNS MRI (multiple solid, round cystic lesions) during neuro
MRI, Fundoscopic examination, elevated serrum T gondii specific
                                                                       workup. 50% of neurocysticercosis patients have GI colonization by
IgM antibodies, and monoclonal gammopathy of IgG, Lumbar
                                                                       adult worms, thus eggs & proglottids in stool. Calcified muscular
puncture - CSF pleocytosis and elevated protein values.
                                                                       cysts appear on x-ray & may be palpable


Acute toxoplasmosis is asymptomatic in 80-90% of healthy hosts
                                                                       Obstructive hydrocephalus from intraventricular cysticerci, blindness
or mild symptomatic infection. In immunosuppressed patients:
                                                                       from ocular cysticerci. Cyst death may result in asymptomatic
rapidly progressive and fatal disease. Fatal for fetus, cause
                                                                       calcifications or may cause intense inflammatory reaction
abortion or neonate death

                                                                       Prednisone & anticonvulsants for acute neurocysticercosis (seizures,
Pyrimethamine and sulfadiazine comb Clindamycin- AIDS/HIV
                                                                       ↑ICP, etc). Albendazole to tx disease, praziquantel is 2nd line. Surgical
patients. Spiramycin- pregnant women
                                                                       removal if ventricular obstruction. Tx GI infection if needed.

                                                                       Treatment of asymptomatic patients debated because cysts may not
Bone marrow suppresion and liver toxicity. Low folate due to
                                                                       respond (dead or calcified), or resulting inflammatory reaction could
pyrimethamine - folic acid antagonist
                                                                       be worse than the disease.

                                                                       Neurocysticercosis is most common CNS parasite disease. Leading
Transmitted domestically by Cat feces Causes encephalitis and          cause of seizures in developing countries. Viable cysticerci cause
hydrocephalous in the neonate                                          little reaction (may be seizure focus or obstruct CSF). Cysts die after 5
                                                                       yrs causing inflammation & onset of s/s in most.

                                                                       Life cycle requires pig contact with human excreta, incidence is high in
Immunodeficient individuals: fetuses, newborns, and                    areas of poor sanitation. Contact with pigs or with others who have
immunologically impaired patients.                                     contact with pigs. Most common in US among immigrants & those in
                                                                       contact with immigrants harboring adult worms

								
To top