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96 Cards in this Set
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central nervous system infections (CNSI)
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threatens persons ability to move feel and think normally
destroy nerve cells leaving victim paralyzed complete loss of finger or toes and deformities |
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central nervous system
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brain
skull meninges spinal cord vertebrae |
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meningitis
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inflamm or infection of meninges
bacterial meningitis viral meningitis |
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meningoencephalitis
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inflamm or infection of the meninges and the brain
high fever headache stiff neck, naausea and vomiting photophobia confusion, sleepiness, seizures |
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main causes of bacterial meningitis
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strepto pneumoniae
neisseria meningitis myvobacterium leprae |
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main causes of bacterial meningitis newborns
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e coli k1
stepto agalactiae listeria monocytogenes |
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bacterial meningitis
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Inflammation of the covering of the brain and spinal column
Can result in irreversible neurological damage (blindness, deafness, learning deficiencies) and death Spread by direct close contact with the discharges from the nose or throat of an infected person (crowded places like dorms, barracks, etc.) |
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bacterial meningitis symptoms
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Persons over age 2 - high fever, headache, and stiff neck
Newborns and infants - symptoms of fever, headache, and neck stiffness may be hard to detect. Other signs in babies might be inactivity, irritability, vomiting, and poor feeding. As the disease progresses, patients of any age can have seizures |
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bacterial meningitis prevention
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depends on use of vaccines, rapid diagnosis, and prompt treatment of close personal contacts
There are vaccines against H. influenzae type B, some strains of N. meningitidis, and many types of S. pneumoniae |
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bacterial meningitis in newborns
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Streptococcus agalactiae
Colonizes the vagina in 15-40% of pregnant women A major cause of meningitis in newborns Culture positive women treated with antibiotics prior to and during labor Has led to a drop of > 75% E. coli (Gram negative rods from mother’s GI tract) Maternal antibodies against these are of the IgM type and thus do not cross the placenta |
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meningococcal meningitis symptoms
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Cold, headache, fever, pain and stiffness of the neck and back, nausea and vomiting
progress to death w/n hours Petechiae (purplish spots) appear on the skin |
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meningococcal meningitis
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There are 13 antigenic groups of N. meningitidis, most serious infection are due to A, B, C, Y and W135
The causative agent of meningococcal meningitis is Neisseria meningitidis |
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meningoccal meningitis patho
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Infection is acquired by inhaling airborne droplets from the respiratory tract of another person. Also, humans are the only source of the infection A). N. meningitidis attach to the mucous membrane by pili. B). They invade the bloodstram. C). The blood carries the bacteria to the meninges and cerebrospinal fluid
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meningococcal meningitis treatment
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A vaccine composed of purified capsular polysaccharides of N. meningitidis serogroup A, C, Y and W135 is availible The antibiotic rifampin is given as a prophylactic treatment to the people, who are intimately exposed to cases of meningococcal disease
spreads rapidly in overcrowded stressed populations |
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listeria monocytogenes
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Motile, non-spore forming, facultative anaerobic Gram+ rod. Grows in macrophages and at 4oC
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listeria monocytogenes patho
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Worlwide distribution in animals, plants and soil
Transferred to humans by contact with animals or their feces, by unpasteurized milk and cheese, and by contaminated vegetables (Slaw) Infections occur in primarily 2 clinical settings: Fetus or newborn as a result of transmission across the placenta or during delivery Infected mother may be asymptomatic or has an influenza-like illness Immune suppressed patients Can lead to sepsis or meningitis |
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listeria monocytogenes treatment
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Cook meat thoroughly, wash row vegetables, avoid soft cheeses (when pregnant)
Ampicillin is an effective antibiotic against L. monocytogenes |
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hansens disease leprosy
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is a granulomatous disease of the peripheral nervous system caused by Mycobacterium leprae
M. Leprae is aeroboc, acid-fast, and rod-shaped bacterium, which grows very slowly (generation time: ~ 12 days |
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hansens disease leprosy symptoms
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Onset of increased or decreased sensation in certain areas of skin, which later enlarge and thicken.
The nervous system of the arms and legs becomes visibly enlarged with accompanying pain, later changing to numbness, muscle wasting, ulceration, and loss of fingers or toes. |
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tuberculoid leprosy
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is the limited type of leprosy disease in which cellular immunity suppresses proliferation of the M. leprae
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lepromatous leprosy
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When cellular immunity and delayed hypersensitivity to M. leprae fail to develop or are suppressed, unrestricted growth of M. leprae occours in the skin macrophages and peripheral nerves,- this form of Hansen’s disease
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lepromatous leprosy epid
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direct human-to-human contact. The source of the organisms is mainly nasal secretions of a lepromatous case.
Natural infections with M. leprae occur in wild nine-banded armadillos and in mangabey monkeys |
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lepromatous leprosy treatment
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Dapsone, rifampin, and clofazimine are effective antibiotics against M. leprae
No vaccine against leprosy is yet availible |
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botulism
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principal symptom is paralysis
Clostridium botulinum Gram (+), spore forming rod Endospores generally resist boiling for hours Killed by autoclaving three types foodborne, intestinal and wound |
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botulism epid
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produces endospores that are highly resistant. The spores germinate if the environment is favorable and growth of the bacteria results in the release of exotoxin into the food. The exotoxin can be absorbed by the small intestine, and can circulate in the blood-stream for several weeks. This toxin is a neurotoxin, and is one of the most powerful toxins known.
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botulism symptoms
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Dizziness, dry mouth, blurred or double vision, abdominal pain or diarrhea. But most dangerous form is paralysis
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botulism epid
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is widely distributed in soils and aquatic sediments around the world. In the early part of the twentieth century, outbreaks of foodborne botulism were common in the United States. Today, intestinal botulism is much more common.
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botulism treatment
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The toxin is heat-labile, and heating food to 100°C for 15 min. just prior to serving generally makes it safe to eat.
Cleaning infected wounds of dirt and dead tissue. Intravenous administration of antitoxin. |
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viral meningitis
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Aseptic meningitis
Meningitis not due to a bacterial pathogen Viral meningitis is much more common than bacterial meningitis, but it is usually a mild diseaseSmall, non-enveloped RNA virus, member of the enterovirus subgroup of picornaviruses, are responsible for at least half of viral meningitis cases. Most common offenders are coxsackie viruses (cause throat or chest pain) and echo viruses (cause rash) Mumps an infrequent cause |
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viral meningitis symptoms
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Typically abrupt in onset
Similar to bacterial meningitis (headache, pain, nausea and vomiting) Usually a benign illness |
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viral meningitis patho
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Begins with infection of throat and intestinal epithelium
Progresses to lymphoid tissue in the bloodstream Viremia results in meningeal infection May also be responsible for rash and chest pain |
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viral meningitis epid
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Relatively stable in environment
Can survive in chlorinated water Infected often eliminate virus in feces Often for weeks Transmission via fecal-oral route Mumps virus transmitted via respiratory droplets |
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viral meningitis treatment
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Handwashing and avoidance of crowded swimming pools
When aseptic disease present in community No vaccine against coxsakievirus and echoviruses Mumps virus controlled via immunization |
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viral encephalitis
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can cause permanent disability or death
Arboviruses Arthropod borne viruses Togavirus (Eastern and Western Equine Viruses) Flavivirus (St. Louis encephalitis, yellow fever, dengue virus) Bunyavirus (California equine virus) Reovirus (Colorado tick fever virus) Transmitted by insects, mites and ticks Viruses enveloped single stranded RNA viruses |
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viral encephalitis symptoms
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Onset usually abrupt
Fever, headache, vomiting, and one or more CNS abnormalities Disorientation, localized paralysis, deafness, seizures or coma |
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viral encephalitis patho
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Viruses multiply at site of bite and in local lymph
nodes Produces viremia Virus crosses blood-brain barrier Causes extensive damage to brain tissue in severe cases Progression of disease halted with appearance of neutralizing antibody Mortality ranges from 2% to 50% depending of type of infecting agent Disabilities often present in those who recover |
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viral encephalitis treatment
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Animals often used to identify emergence of disease
Prevention directed towards Avoiding outdoor activities at night when mosquito populations highest Make sure windows and porches properly screened Use insect repellents and insecticides No proven antiviral therapy |
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poliomyelitis
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Causative agent- Poliovirus
Picornavirus (non-enveloped, single stranded RNA viruses) 3 antigenic types Protection requires antibody to all 3 types Characteristic feature of poliomyelitis is selective destruction of motor nerve cells |
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poliomyelitis patho
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Transmission occurs by the fecal-oral route
Immune system conquers infection in most people Viruses spreads through blood stream to CNS Virus replicates in motor nerves of the brain and spinal cord |
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poliomyelitis symptoms
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Headache, fever, stiff neck, nausea, pain, paralysis, muscle-shrinking and in an infected area the bones do not develop normally
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poliomyelitis treatment
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Babies receive antibodies transplancentally from their mothers
Control directed at vaccination Salk vaccine Inactivated vaccine (formalin-killed) Sabin vaccine Attenuated vaccine Advantages Given orally Induces sec. IgA which interrupts fecal-oral transmission Disadvantages Rare reversions Can cause disease in Immune deficient individuals Infection of other enteroviruses in GI tract can limit replication of vaccine virus and limit protection Must be refrigerated. |
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rabies
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Causative agent- rabies virus
Rhabdovirus family (enveloped, single stranded RNA viruses) most feared of all diseases because of its terrifying symptoms |
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rabies symptoms
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Fever, headache, nausea, vomiting, sore throat; later, spasms of the muscles of mouth and throat, coma.
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rabies patho
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Transmission of rabies to humans occurs via the saliva of a rabid animal
When the virus enters an axon it is carried along the course of the nerve by the normal flow of the axon’s cytoplasm, eventually reaching the brain. The virus then multiplies extensively in brain tissue, causing the symptoms of encephalitis. Characteristic inclusion bodies, formed by rabies virus, are called Negri bodies |
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rabies epid
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Bite of rabid animal, usually a bat, and/or inhalation
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raibes treatment
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Avoid suspect animals. Immunize pets, immedietly wash wound and apply antiseptic
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cryptococcal meningoencephalitis
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Cryptococcal meningitis is an infection of the meninges and brain by fungus Cryptococcus neoformans
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crpto menin syptoms
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dizziness, headache, vomiting, weight loss, seizure, paralysis, and coma
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crpto menin patho
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Infection starts in lung. C. neoformans multiply, enter the bloodstream and are carried to various parts of the body. They can invade the meninges and the brain.
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crypto menin epid
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C. neoformans is located in soil and vegetation, especially in soil where pigeon droppings accumulate. Infection is contracted by inhaling contaminated dust
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crypto menin treatment
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No vaccine or other preventive measure available. Treatment with the antibiotic amphotericin B is effective
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african trypanosomiasis
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Trypanosomiasis is an Infection of the blood and central nervous system caused by trypanosoma
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african trypanosomiasis symptoms
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fever, headache, uncontrollable sleepiness, poor concentration, and coma
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african trpy patho
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During the bite by an infected tsetse fly, the trypanosomes enter the bite wound in the fly’s saliva. Trypanosomes multiply and enter the lymphatic and blood circulation. They can infect the CNS
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african tryp epid
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African trypanosomiasis occurs on the African continent with 10.000 - 20.000 new cases each year. The occurrence of the disease is determined by the distribution of the tsetse fly vectors.
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african tryp treatment
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Protective clothing, insecticides; Melarsporol, eflornithine, and suramin
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transmissible spongiform
Encephalopathy (TSE) |
TSE is a brain disease. It is very rare in humans (1/1.000.000 people
Prions (PrP) proteinaceous infectious particles |
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tse symptoms
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Muscle jerks, lack of coordination, memory loss, and loss of muscle function
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tse patho
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Infection starts in the spleen and other lymphoid tissues. The prions are then transported to the central nervous system by B lymphocytes.
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tse epid
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Generally occurs in individuals older than 45 years. Transmission of cattle prions to humans probably occurred by eating contaminated beef.
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tse treatment
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Using of absolutely sterile surgical instruments. Autoclaving inactivate prions
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gram negative septicema
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Gram (-) bacteria more likely cause of fatal septicemia
Shock is common despite treatment Mortality rate nearly 50% Blood cultures from patients usually reveal E. coli Gram (-) facultative anaerobe P. aeruginosa Gram (-) aerobe Generally found in natural environment Bacteroides sp. Gram (-) aerobe Part of normal intestinal and upper respiratory flora |
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gn septicemia symptoms
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Chills, fever, low-blood pressure
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tularemia rabbit fever
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F. tularensis
High virulent (Category A agent of biological terrorism), Non-motile, aerobic Gram (-) rod. It requires a special medium enriched with cysteine in order to grow. serious infectious disease |
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rabbit fever patho
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F. tularensis causes ulcer where it enters the skin.
It spreads via lymphatic and blood vessels. Pneumonia occurs when bacteria infect the lung from the bloodstream or by inhalation. F. tularensis can survive and replicate in macrophages. Syndromes: Ulceroglandular (70-85%), glandular, typhoidal, pneumonic, oculoglandular, oropharyngeal |
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rabbit fever symptoms
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Ulcer in side of entry, enlarged lymph nodes, fever, chills, and achiness.
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rabbit fever epid
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In the west US infections result from the bites of infected ticks
and deer flies, and usually occur during the summertime. In Europe epidemics of inhalation tularemia have occurred from dust arising from moving lawns or rodent infested buildings. skinning rabbits |
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rabbit fever treatment
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Uses of Rubber gloves and goggles when working with animal carcasses
Inspect routinely for ticks after exposure Live, attenuated vaccine available for workers at higher risk of exposure Streptomycin is DOC but also treated with gentimicin cell mediated imunity |
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francisella tularenis
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95% DNA genomic sequence identity
tularensis (type A) holarctica (type B) novicida |
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tularensis type a
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Two copies of FPI (Francisella Pathogenicity Island)
highly virulent in humans potential bioweapon (CDC) |
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holarctica type b
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Two copies of FPI
moderately virulent in humans live vaccine strain (LVS) is an attenuated form of holarctica |
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novicida
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One copy of FPI (97% homology to spp. tularensis)
avirulent to humans, unless immunocompromised virulent to mice |
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brucellosis undulant fever
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Four varieties of genus Brucella cause disease in humans (all fall into a single species Brucella melitensis)
Traditionally each variety given own species name depending on preferred host B. abortus -cattle B. canis - dogs B. melitensis - goats B. suis - pigs Organism is Gram (-) rod domestic animals |
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undulant fever symptoms
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Onset usually gradual and symptoms are vague
Aches and pains, enlarged lymph nodes, weight loss, and fever Because of the recurrence in some cases of fevers over weeks or months, brucellosis is also called: “undulant fever”. Without treatment most cases recover within 2 months 15% will be symptomatic for 3 months or longer |
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undulant fever epid
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Chronic infection of domestic animals
Generally involving the mammary gland and uterus (organs rich in sugar) Causes contaminated milk and abortions Abortion not a feature of human disease Occurs in workers in meat packing industry Major problem in animals used for food |
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undulant fever patho
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Organism penetrates mucous membranes or break in skin
Disseminated via lymphatic or blood vessels Generally to heart and kidneys Spleen enlarges in response to infection Organisms resistant to phagocytic killing Can grow within phagocytes (inaccessible to antibodies or antibiotics) Mortality generally due to endocarditis The most frequent serious complication is bone infection, Osteomyelitis |
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undulant fever treatment
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Pasteurization most important control measure
- Inspection of domestic animals - Protective eyewear and gloves when working with animals or animal carcass - Attenuated vaccine controls disease in domestic animals - Tetracycline combined with rifampin used for treatment Treatment usually given for 6 weeks (very slow growing organisms) |
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plaugue black death
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Plague, once known as the “black death” is caused by Yersinia pestis
Yersinia pestis is a facultative intracellular bacterium, which grows best at 28ºC. |
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plague black death symptoms
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Develop abruptly 1 – 6 days post infection
Transmission via bite from infected flea Disease characterized by large tender lymph nodes called buboes (hence the name Bubonic Plague) Other symptoms include High fever Shock Delirium Patchy bleeding under the skin May also have cough and bloody sputum Only if lungs infected (Pneumonic plague) The dark hemorrhages in the skin inspired the name “black death” |
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black death patho
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Masses of organism obstruct digestive tract of rat fleas
Flea regurgitates infected material into bite wound Most organisms destroyed by neutrophils Organisms multiply within macrophages Produces capsule while in macrophages but not in fleas Macrophages die and release organism. Organism encapsulated and produces Yop proteins and other mechanisms that enhance survival. Inflammation in lymph nodes results in swelling. Lymph nodes become necrotic and spill organisms into the bloodstream - Septicemic plague (endotoxin release results in shock and disseminated intravascuolar coagulation (DIC). Infection of the lung results in pneumonic plaque |
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plague treatment
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Prevention directed by rat control
Proper garbage disposal Rat-proof buildings Guards on mooring ropes Extermination programs Killed vaccine gives short-term partial protection Treatment via tetracycline for some exposed individuals to control epidemics. Gentamycin, ciprofloxacin and doxycycline effective if given early |
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infectious mononucleosis
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Mononucleosis is a viral infection that produces flu-like symptoms. Infected people have an increased number of mononuclear leukocytes in their blood
Epstein-Barr virus Double stranded DNA virus Belongs to herpesvirus family EB virus was first isolated from Burkitt’s lymphoma, a malignant tumor derived from B lymphocytes |
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infectious mononucleosis symptoms
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Appear after long incubation
Usually 30 to 60 days post infection Symptoms include fever, sore throat covered with pus, fatigue, enlarged lymph nodes and spleen Most cases fever and sore throat disappear within 2 weeks, lymph node enlargement within 3 weeks Infection leads to increased number of mononuclear cells in blood stream |
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infectious mononucleosis patho
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Virus infects certain cell types that express the receptor for complement C3D component (CR2 or CD21)
Epithelial cells of oro/naso-pharynx and B cells Infection begins in cells of throat and mouth Virus carried to lymph nodes after replication in epithelial cells of mouth, saliva producing glands and throat Infects B lymphocytes Infection can be productive or nonproductive Productive – kills cells Nonproductive – virus is latent Virus activates B cells to produce multiple clones of B lymphocytes to proliferate and produce immunoglobulin T lymphocytes destroy infected B cells. Abnormal-appearing lymphocytes are activated T cells |
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infectious mononucleosis epid
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Distributed worldwide
Infects individuals in crowded, economically disadvantaged areas Infects at early age without producing symptoms producing immunity More affluent populations missed exposure and lack immunity Occurs almost exclusively in adolescents and adults who lack antibody Virus present in saliva for up to 18 months Mouth-to-mouth kissing important mode of transmission No animal reservoir |
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infectious mononucleosis treatment
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Avoiding saliva of another person
Kissing, sharing soft drinks No vaccine Acyclovir inhibits productive infection Has no activity on latent viruses |
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yellow fever
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Enveloped, single stranded RNA arbovirus
Belongs to flavivirus family Virus multiplies in mosquitoes RNA arbovirus, that is transmitted to humans through the bite of infected mosquitoes |
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yellow fever patho
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Mosquitoes (Aedes mosquitoes) transmit virus to humans via bite.
Multiplies and enters blood stream Carried to liver Jaundice results in liver damage Injury to small blood vessels leading to DIC Damage heart muscle Kidney failure is a common consequence of disease Loss of circulating blood and low blood pressure |
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yellow fever symptoms
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Disease can range from mild to severe
Most common form may be fever and slight headache lasting a day or two Severe disease: high fever, nose bleeds and bleeding into the skin, “black vomit” from GI bleeding and jaundice (hence the name “Yellow Fever”) Mortality rate of severe disease can reach 50% Reason for the variation in symptoms is unknown |
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yellow fever epid
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Reservoir mainly infected mosquitoes and primates in tropical regions of Central and South America and Africa
Periodically spread to urban areas via mosquito bite |
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tellow fever treatment
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Control achieved by spraying and elimination of breeding sites of its principal vector Aedes egypti (almost impossible in jungle regions)
Attenuated vaccine available for high risk groups No proven antiviral treatment |
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malaria
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Human malaria caused by four species of genus Plasmodium
P. vivax, P. falciparum, P. malatiae, P. ovale Infectious form of parasite injected via Anopheles mosquito |
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malaria symptoms
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First symptoms: fever, headache, and pain in the joints and muscles
After 2-3 weeks the symptoms fall into three phases highly suggestive of malaria Cold phase Hot phase Wet phas |
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malaria patho
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The characteristic feature of malaria (after high fever feeling healthy again), results from erythrocytic cycle of growth and release of merozoites
Mararia is the most common cause of splenic rupture, which can occur with, or without trauma P. falciparum tends to be very severe. It infects erythrocytes of all ages Other Plasmodium species infect only young or old erythrocytes P. vivax and P. ovale develop treatment-resistant forms and, months after treatment, they can begin multiplying in exoerythrocytic cycle |
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malaria epid
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Once common in both temperate and tropical areas
Now dominant disease of warm climate Eliminated from continental U.S. in late 1940’s Mosquitoes of genus Anopheles are biological vectors Infected mosquitoes and humans constitute reservoir Transmission via mosquitoes, blood transfusion and sharing of syringes |
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malaria treatment
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Mosquito control
Treatment is complicated Due to different stages of mosquito life cycle Chloroquine Effective against erythrocyte stage Will not cure liver infection Primaquine and tafenoquine Generally effective against exoerythrocyte stage and certain species gametocytes |
