Disease Agents Flashcards
What bacteria causes Q fever?
Coxiella burnetii, Gram negative bacteria, obligate intracellular parasite
What is Q fever?
respiratory disease(inhaled), high fever (104-105), originally- slaughterhouse workers in Australia, etiology -(query fever), most infectious disease in the world(treatable with antibiotics)
What is Coxiella burnetti used for?
the standard for pasteurization of milk, heat resistant
What is a virus?
Infectious agent, unable to grow outside host, obligate parasite, multiply inside living cells, single type of nucleic acid (DNA or RNA, not both), contains a protein coat
How many people can touch a doorknob and transfer a virus?
14 successive via doorknob and 6 from original person
What is the main difference between bacteria and viruses?
intracellular parasite and pass through bacteriological filters
What are the predominant viruses that can cause illnesses?
Astrovirus, Rotavirus, Sapovirus, Norovirus, Hepatitis A virus
When and where was Norovirus emerged?
1968 in Norwalk, OH, previously known as Norwalk or Norwalk-like viruses(NLV), RNA virus
How is Norovirus transmitted?
Primarily thru the fecal-oral route, person-to-person, fomites, contact surfaces, foods, Highly Contagious
What is the infectious dose for Norovirus?
10-100 viral particles
What is the cause of the most common cause of acute gastroenteritis?
Norovirus “stomach flu” , 5.5 million cases/yr US (set)
What are the symptoms for Norovirus?
humans are the only known host, onset 24-72 hours, Primary: nausea and vomiting, secondary:diarrhea, abdominal pain, headache, low grade fever, duration: typically 12-72 hours,
infected- contagious from onset of feeling ill, up to 2 weeks after recovery
Diagnosed by RT-PCR
What is the infectious Hepatitis?
Hepatitis A vrius, Picornavirus
What does Picornavirus stand for?
pic=small + RNA + virus
What are the symptoms for Hepatitis A virus?
replicates in the liver, 2 weeks before onset, onset 15-50 days, average 30 days, fever, nausea, anorexia, jaundice
Duration: 1-2 weeks, slow recovery
more common in adults
Diagnosis: immunassays
How is Hepatitis A virus transmitted?
Infected food handler, fecal-oral-route, person-to-person, contaminated food- raw shellfish, contaminated H20, contaminated food surfaces
How can you control Hepatits A virus?
Heat for 10 in @ 80 C to reduce 4.3 logs, inactivated by 70% EtOH or 10 ppm free residual chlorine, immunoglobin within 2 weeks of exposure
What is Amebiasis?
parasitic protozoa, Amoebic dysentery, Entamoeba histolytica, from contaminated food, water, hands, only 10-20% of infected people become sick
What are the symptoms from Amoebic dysentery?
severe diarrhea, treated with amebicidal drugs, looks similar to cells
What do Cryptosporidium parvum cause and it’s symptoms?
cryptosporidiosis, 2-10 days, self limiting, microscopic examination of stool. (acid sating, fluorescent antibodies, PCR
What major case had to deal with Cryptosporidium parvum?
Milwaukee, WI-1993, municipal water, >400,000 infected, larger water-borne disease outbreak in US history
Describe Cyclospora cayatanensis.
incubation approx. 1 week, duration 10-12 weeks, 11 food borne outbreaks since 1990-US &Canada appr. 3600 people
How is Cyclospora cayatanensis treated?
trimethoprim-sulfamethoxazole, fluids and electrolytes
What is the leading cause of death in the US?
Toxoplasma gondii (toxoplasmosis)
How is Toxoplasma gondii (toxoplasmosis) diagnosed and treated?
direct observation of stained:
tissue sections
cerebrospinal fluid
other biopsy
direct isolation of parasites from blood or other fluids
PCR
Treatment: pyrimethamine and sulfadiazine
What are Mycotoxins?
toxins produced by molds as secondary metabolites, formed when large pools of primary metabolic precursor( amino acids, acetate, pyruvate) accumulate
Why are mycotoxins produced?
synthesized to remove primary precursors, initiallized at onset of stationary phase, occurs with lipid synthesis
