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
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
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.
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
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
disseminate infection to organs (liver, lung, GI tract).
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,
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
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
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
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
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
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)
– 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
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
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
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
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
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
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
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
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.
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
decreased level of consciousness, seizures, & deficits of the making diagnosis difficult malaria will die.
Destroys brain tissue and leads to death.
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.
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
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