Q&A Hero

Q: What is the difference between food poisoning and food infection? Are antibiotics useful in either of them?

Q: Why is Staphylococcus aureus often described as an international picnic pest?

Q: How does Clostridium perfringens cause food poisoning? How is this process related to the metabolism and special structures of C. perfringens?

Q: Why are enteric bacteria such as Escherichia coli common meat contaminants?

Q: What makes Listeria monocytogenes an especially difficult-to-prevent foodborne pathogen? Once in the human body, how does it evade the immune system?

Q: There were numerous cases throughout the United States of patients having bloody diarrhea all within a week of each other, many of which were hospitalized with severe cases. Although the people spanned from California to New York, they all had attended a high school graduation party. Epidemiologists determined the common food factor was cheese curds homemade by a farmer. The home where the cheese curds were made was searched, and the cheese curds and milk used to produce them were taken to the local government lab. Among other microbes, Campylobacter jejuni was isolated from many of the cheese curds as well as the farmer's bulk tank milk. What should be done for those infected? What can be done to prevent this from happening again?

Q: Compare and contrast the most probable number (MPN) procedure and the membrane filter (MF) procedure.

Q: Explain why coliforms are used to detect water contamination rather than directly quantifying individual pathogens such as Vibrio cholerae or Salmonella spp.

Q: Escherichia coli is found naturally in the intestines of birds, humans, and animals.

Q: Campylobacter infections are the MOST common foodborne infections in the United States.

Q: Gram-negative bacteria are responsible for causing MOST foodborne diseases.

Q: Nearly ALL cases of acute listeriosis require hospitalization.

Q: During a camping and hiking expedition in the Ice Age National Scenic Trail at Hartman Creek State Park (Waupaca, WI), an individual notices a small tick on his arm. After removing the partially embedded deer tick, what symptoms should this individual look for to indicate infection of Borrelia burgdorferi? Also, what should be done on future hiking trips to decrease the likelihood of B. burgdorferi infection?

Q: Using a specific example, explain the term "accidental host."

Q: Compare and contrast dengue fever and West Nile fever. Which disease would be easier to eradicate and why?

Q: What key features of Bacillus anthracis makes the anthrax disease impossible to eradicate?

Q: How is climate change causing the emergence of zoonotic and vector-borne in new human populations?

Q: The Black Plague has killed millions of humans over the course of history, yet we do not vaccinate against this disease. Why is this and how is the disease controlled in modern human populations?

Q: During outdoor activities, it is not uncommon to be bitten by mosquitoes several times, so how does an individual know he/she has been infected with the West Nile virus? How would an infected individual be treated for the disease?

Q: What is the primary cause of viral hemorrhagic fever in the United States? What is the typical cause of death for this disease?

Q: Where does the rabies virus reproduce? Using a specific example, explain the implication this has with the virus's incubation time and infection site.

Q: Explain why a potentially rabid dog is held for up to two weeks to check for clinical signs of rabies. Are humans more similar or dissimilar in this regard?

Q: The study of hantaviruses requires biosafety level (BSL) 4 precautions.

Q: Septicemic plague usually causes death before a diagnosis can be made.

Q: Virtually ALL cases of tetanus occur in individuals who have failed to receive tetanus toxoid booster immunizations.

Q: Wild animals are a natural reservoir for Clostridium tetani.

Q: Tetanus is highly contagious through person-to-person contact.

Q: A PCR assay has been developed for the detection of the bacterium (Borrelia burgdorferi) that causes Lyme disease. Unfortunately this method cannot differentiate between an active disease and a treated or inactive disease.

Q: Lyme disease is limited almost exclusively to the northeastern United States.

Q: Tetracycline and chloramphenicol are the drugs of choice for the treatment of many of the rickettsial diseases.

Q: Rickettsia prowazekii is transmitted to humans when a louse bite becomes contaminated with louse feces.

Q: There are several different virus-specific treatments and vaccines available to treat or prevent hantavirus infections.

Q: The hantavirus diagnosis can be made from several different types of ELISAs.

Q: The hantaviruses are occasionally spread by person-to-person transmission, although exposure to infected rodent excretia is the most common route of infection.

Q: Erythema migrans is associated with typhus.

Q: Epizootic diseases often occur in wild animals on a periodic or cyclic basis.

Q: Rabies infection in humans leads to symptoms a few days after exposure.

Q: Only high-risk individuals such as scientists working with the organism, livestock workers, and military personnel are vaccinated for anthrax.

Q: . Travelers should be vaccinated against yellow fever when traveling to Sub-Saharan Africa or South America.

Q: Deer flies (Chrysops spp.) are a major vector in the spread of typhus.

Q: Certain Clostridium spp. can be found in the human gut, but Clostridium tetani is almost exclusively present in soil.

Q: Both yellow and dengue fever can be prevented by vaccines.

Q: Inhalation anthrax is the only form of anthrax for which there is no effective treatment.

Q: Anthrax is an emerging disease for which there is no treatment or vaccine available.

Q: The majority of cases of human plague in the United States occur in the northeastern states.

Q: Various Ixodes spp., as well as various Borrelia spp., may be involved in the transmission and cause of Lyme disease.

Q: If Lyme disease is not treated early, it can infect the central nervous system.

Q: Emerging diseases are a problem worldwide, even in highly developed regions of the world.

Q: Hantaviruses are related to viruses such as ________ and ________. A) human immunodeficiency virus (HIV) / Hepatitis C B) Hepatitis A / Hepatitis B C) human immunodeficiency virus (HIV) / Influenza A D) West Nile virus / Ebola virus

Q: Controlling most rickettsial diseases involves managing A) the vector. B) human behavior. C) immunization strategies. D) food safety procedures.

Q: The causative agent of dengue fever is A) Rickettsia prowazekii. B) a flavivirus. C) Borrelia burgdorferi. D) Clostridium perfringens.

Q: Hantavirus pulmonary syndrome is a viral respiratory disease caused by contact with A) rat fleas. B) rodents. C) mosquitoes. D) bats.

Q: The causative agent of Lyme disease is ________, which is carried primarily by the ________. A) a flavivirus / Ixodes sp. (deer tick) B) Yersinia pestis / Xenopsylla cheopis (rat flea) C) Rickettsia prowazekii / Culex species (mosquito) D) Borrelia burgdorferi / Ixodes sp. (deer tick)

Q: Which of the following was an emerging mosquito-borne disease in the early 2000s but has now decreased in frequency? A) malaria B) Rocky Mountain spotted fever C) typhus D) West Nile fever

Q: The most severe and fatal form of anthrax is A) cutaneous anthrax. B) inhalation anthrax. C) intestinal anthrax. D) zoonotic anthrax.

Q: A person is MOST likely to contract diseases such as Rocky Mountain spotted fever and ehrlichiosis if he or she visits/participates in A) camping and hiking in the backcountry. B) metropolitan cities. C) snow skiing. D) European countries.

Q: The primary disease reservoir for plague is A) fleas. B) humans. C) rats. D) mosquitoes.

Q: In bubonic plague, buboes are swellings formed in the lymph nodes and filled with A) Yersinia pestis. B) Rickettsia prowazekii. C) Xenopsylla cheopis. D) Clostridium tetani.

Q: Murine toxin is a ________ that plays a role in both the murine and human forms of the disease. A) Yersinia pestis endotoxin B) Rickettsia prowazekii endotoxin C) Yersinia pestis exotoxin D) Rickettsia prowazekii exotoxin

Q: Tetanus develops from a puncture wound because A) endospores germinate in anoxic conditions. B) the organism gains access to the circulatory system and then invades the nervous system. C) the organism digests deep connective tissues. D) the organism needs access to the circulatory system and deep connective tissues.

Q: The disease whose symptoms are most closely related to the symptoms of chronic syphilis is A) Rocky Mountain spotted fever. B) latent Lyme disease. C) typhus. D) HPS.

Q: Rickettsial disease detection/identification includes which of the following? A) latex bead agglutination assays B) ELISA C) PCR assays D) latex bead agglutination assays, ELISA, and PCR assays

Q: Which of the following diseases causes an influenza-like illness that can progress to include pneumonia? A) malaria B) Q fever C) typhus D) Lyme disease

Q: Many West Nile virus infections are not properly identified because A) the disease mimics malaria. B) the symptoms are often subacute. C) the disease is frequently fatal. D) most physicians and diagnosticians are not aware of this disease.

Q: What virulence factor(s) of Yersinia pestis prevent(s) phagocytosis by cells of the immune system? A) the capsule B) leukocidins C) murine toxin D) V and W antigens

Q: Which disease(s) has/have been mistakenly diagnosed as measles or scarlet fever due to similarities in rash appearance? A) Lyme disease B) Q fever C) rickettsial diseases D) typhus

Q: Which rickettsial disease can lead to endocarditis? A) Q fever B) typhus C) Rocky Mountain spotted fever D) scrub typhus

Q: Which of the following pathogens is spread by infected lice? A) Borrelia burgdorferi B) Plasmodium falciparum C) Rickettsia prowazekii D) Yersinia pestis

Q: The rickettsias are divided into groups based loosely on A) the types of clinical disease they produce. B) their insect vectors. C) taxonomy. D) their biochemical requirements.

Q: The rickettsias can be cultured in A) pure culture. B) artificial media. C) laboratory animals. D) pure culture, artificial media, and laboratory animals.

Q: Hantaviruses are most commonly transmitted by ________ of virus-contaminated rodent ________. A) inhalation / saliva B) inhalation / excreta C) ingestion / saliva D) ingestion / excreta

Q: The hantavirus contains a ________ genome. A) ssRNA B) dsRNA C) ssDNA D) dsDNA

Q: Soldiers or refuges in crowded unsanitary conditions are MOST susceptible to which rickettsial disease? A) Lyme disease B) typhus C) Q fever D) Rocky Mountain spotted fever

Q: Animal-transmitted diseases are generally spread to accidental hosts by A) direct contact. B) aerosols. C) bites. D) direct contact, aerosols, and bites.

Q: Very few preventative measures are taken against anthrax, because A) the general population is not exposed to infected materials or animals regularly. B) non-weaponized anthrax causes only a mild flu-like illness. C) no vaccines are effective. D) the causative agent Bacillus anthracis mutates rapidly.

Q: Which of the following diseases CANNOT easily be controlled by vector elimination? A) yellow fever B) dengue fever C) rabies D) plague

Q: What type of diseases require biosafety level (BSL) 4 procedures and facilities when working with samples that may be infected? A) highly infectious diseases B) diseases with high mortality C) diseases for which no treatment or vaccine exist D) highly infectious diseases with high mortality for which no treatment or vaccine exist

Q: Which of the following would be the best strategy to prevent the spread of yellow fever and dengue fever into the southern United States? A) mosquito avoidance and eradication B) vaccination C) monitoring bird populations D) tick avoidance

Q: Which insect functions in the host-to-host transmission of typhus? A) rat flea B) body louse C) dog tick D) deer tick

Q: If you were exposed to a sick animal that was found to have negri bodies in its nervous system in a postmortem examination, how would you be treated to prevent disease? A) passive and active immunization against rabies B) antibiotics to treat Lyme disease C) antiviral medication D) observation to detect tick or lice bites