MIC205A – Microbiology – “The List” Pathogens Questions and Answers
1. Enterobius vermicularis - Pinworm (parasite)
- Symptoms: some asymptomatic, itching in and around the anus mainly at night caused by
migrating worms, insomnia, restlessness
- Symptoms in children: loss of appetite, weight loss, irritability
- Human to human transmission by ingesting infectious eggs
- Cold, moist environment
- Eggs hatch in small intestine and larvae move to colon to rectum, females lay eggs in anus
- Prevention: good hygiene
- Treatment: medication
2. Taenia solium - Pork tapeworm
- No body cavity, long and ribbon like
- Passes through pigs to (larval state) humans (ingest pork), humans release eggs in feces
- Sometimes asymptomatic, intestinal irritation, anaemia, indigestion, loss of appetite
- Cause cysticercus - headache, dizzy, seizures, brain lesions, epilepsy
- Prevention: make sure pork is cooked thoroughly, good sanitation and hygiene
- More common in cosmopolitan areas
3. Human papillomavirus (HPV) - Double-stranded DNA virus
- Non-enveloped, STI
- Transmission: having sex with an infected person
- Causes: genital warts, cervical cancer
- Prevention: get vaccinated, get screened for cancer, use condoms, limit sexual partners
- Vaccine: all boys and girls should get it at age 11 or 12, catch up vaccines offered for older
aged individuals
,- No test to see if infected - known when genital warts appear or strange pap results
- Most people infected don't know they have it, many never develop symptoms
4. Smallpox (variola) virus - Double-stranded DNA virus
- Zero cases since 1977
- Transmission: direct/close contact with infected person
- Patients contagious once the first sores appeared in the mouth and throat, contagious until
last scab fell off
- Incubation period, initial symptoms, early rash (contagious!), pustular rash and scabs, scabs
fall off, no scabs
- Symptoms: fever and body aches, red spotty rash, sores form and break open, sores become
pustules, scabs
- Vaccine: not available to general public because smallpox doesn't exist anymore
- Treatment: none proven, antiviral drugs may help
5. Vaccinia virus (cowpox) - Double-stranded DNA virus
- Zoonotic - dairymaids got it after touching infected cow udders, immune from smallpox
leading to vaccine
- Similar too but more mild than smallpox
- Symptoms: lesions and pustules, mild rash and fever
- Live-virus vaccine against smallpox - today only given to healthcare workers, research
personnel, and military personnel
6. Gardnerella vaginalis - Gram-negative (variable) bacterium
- Short, rounded rod shape, most common vaginal infection (overgrowth/imbalance)
- Causes: Bacterial Vaginosis (BV)
- Transmission: unknown cause, common in sexually active women
,- Pregnant women: premature and/or low birth weight babies
- Symptoms: sometimes none, white/gray discharge, pain/itching/burning, fish-like odor
- Treatment: sometimes none needed, antibiotics
- Men don't get it from female sex partners
7. Echinococcus granulosus - Tapeworm
- Causes: cystic echinococcosis disease
- Transmission: swallowing the tapeworm eggs, direct contact with an infected dog,
consumption of contaminated water/veggies
- Risk factors: uncontrolled dogs living closely to people, uncontrolled slaughter of livestock,
unsanitary living conditions
- Symptoms: no symptoms for years, pain in upper abdomen or chest, nausea/vomiting, cough
- Can die if cysts rupture
- Treatment: surgery, medication
8. Hepatitis B virus - Double-stranded DNA virus
- Causes: severe liver infection
- Transmission: mother to child during birth, exposure to infected blood or other body fluids
(sex, needles,
- Hep B can survive outside the body for at least 7 days
- Symptoms: acute infection phase - none, then jaundice, dark urine, fatigue, nausea, vomiting
- Severe symptoms: liver failure, cirrhosis, liver cancer - can cause death
- 80-90% of infants infected develop chronic infections
- Treatment: medication, Iv fluids
- Prevention: 3 or 4 dose Hep B vaccination
9. Rhinovirus - Single-strand RNA virus, non-enveloped
, - Transmission: through air respiratory droplets or direct contact
- Rhinovirus attaches to the respiratory epithelium and spreads
- Causes: common cold - also has role in bronchitis and asthma
- Symptoms: fever, cough, nasal congestion
- No vaccine
- Prevention: regular hand washing, avoid touching eyes/mouth/nose, wear a surgical mask
10. Norovirus - Single-strand RNA virus, non-enveloped
- Transmission: person-to-person, food or waterborne (fecal to mouth)
- Causes: gastro-enteritis outbreaks (stomach bug)
- Symptoms: vomiting, diarrhea, nausea, cramping
- Virus only lasts 24-72 hours
- 685 million illnesses per year globally (so common)
- Reinfection common
- No vaccine - antigenic drift
11. Trypanosoma brucei - Parasite
- Causes: African trypanosomiasis (sleeping sickness)
- Transmission: African tsetse fly bite (doesn't occur in US)
- Two types: East/West African
- First invades circulation, crosses blood-brain barrier, infects nervous system -> mental
deterioration, sleep disturbances, confusion -> death
- Treatment: medication - relapse common
- No vaccine
- Prevention: cover skin, use repellant
1. Enterobius vermicularis - Pinworm (parasite)
- Symptoms: some asymptomatic, itching in and around the anus mainly at night caused by
migrating worms, insomnia, restlessness
- Symptoms in children: loss of appetite, weight loss, irritability
- Human to human transmission by ingesting infectious eggs
- Cold, moist environment
- Eggs hatch in small intestine and larvae move to colon to rectum, females lay eggs in anus
- Prevention: good hygiene
- Treatment: medication
2. Taenia solium - Pork tapeworm
- No body cavity, long and ribbon like
- Passes through pigs to (larval state) humans (ingest pork), humans release eggs in feces
- Sometimes asymptomatic, intestinal irritation, anaemia, indigestion, loss of appetite
- Cause cysticercus - headache, dizzy, seizures, brain lesions, epilepsy
- Prevention: make sure pork is cooked thoroughly, good sanitation and hygiene
- More common in cosmopolitan areas
3. Human papillomavirus (HPV) - Double-stranded DNA virus
- Non-enveloped, STI
- Transmission: having sex with an infected person
- Causes: genital warts, cervical cancer
- Prevention: get vaccinated, get screened for cancer, use condoms, limit sexual partners
- Vaccine: all boys and girls should get it at age 11 or 12, catch up vaccines offered for older
aged individuals
,- No test to see if infected - known when genital warts appear or strange pap results
- Most people infected don't know they have it, many never develop symptoms
4. Smallpox (variola) virus - Double-stranded DNA virus
- Zero cases since 1977
- Transmission: direct/close contact with infected person
- Patients contagious once the first sores appeared in the mouth and throat, contagious until
last scab fell off
- Incubation period, initial symptoms, early rash (contagious!), pustular rash and scabs, scabs
fall off, no scabs
- Symptoms: fever and body aches, red spotty rash, sores form and break open, sores become
pustules, scabs
- Vaccine: not available to general public because smallpox doesn't exist anymore
- Treatment: none proven, antiviral drugs may help
5. Vaccinia virus (cowpox) - Double-stranded DNA virus
- Zoonotic - dairymaids got it after touching infected cow udders, immune from smallpox
leading to vaccine
- Similar too but more mild than smallpox
- Symptoms: lesions and pustules, mild rash and fever
- Live-virus vaccine against smallpox - today only given to healthcare workers, research
personnel, and military personnel
6. Gardnerella vaginalis - Gram-negative (variable) bacterium
- Short, rounded rod shape, most common vaginal infection (overgrowth/imbalance)
- Causes: Bacterial Vaginosis (BV)
- Transmission: unknown cause, common in sexually active women
,- Pregnant women: premature and/or low birth weight babies
- Symptoms: sometimes none, white/gray discharge, pain/itching/burning, fish-like odor
- Treatment: sometimes none needed, antibiotics
- Men don't get it from female sex partners
7. Echinococcus granulosus - Tapeworm
- Causes: cystic echinococcosis disease
- Transmission: swallowing the tapeworm eggs, direct contact with an infected dog,
consumption of contaminated water/veggies
- Risk factors: uncontrolled dogs living closely to people, uncontrolled slaughter of livestock,
unsanitary living conditions
- Symptoms: no symptoms for years, pain in upper abdomen or chest, nausea/vomiting, cough
- Can die if cysts rupture
- Treatment: surgery, medication
8. Hepatitis B virus - Double-stranded DNA virus
- Causes: severe liver infection
- Transmission: mother to child during birth, exposure to infected blood or other body fluids
(sex, needles,
- Hep B can survive outside the body for at least 7 days
- Symptoms: acute infection phase - none, then jaundice, dark urine, fatigue, nausea, vomiting
- Severe symptoms: liver failure, cirrhosis, liver cancer - can cause death
- 80-90% of infants infected develop chronic infections
- Treatment: medication, Iv fluids
- Prevention: 3 or 4 dose Hep B vaccination
9. Rhinovirus - Single-strand RNA virus, non-enveloped
, - Transmission: through air respiratory droplets or direct contact
- Rhinovirus attaches to the respiratory epithelium and spreads
- Causes: common cold - also has role in bronchitis and asthma
- Symptoms: fever, cough, nasal congestion
- No vaccine
- Prevention: regular hand washing, avoid touching eyes/mouth/nose, wear a surgical mask
10. Norovirus - Single-strand RNA virus, non-enveloped
- Transmission: person-to-person, food or waterborne (fecal to mouth)
- Causes: gastro-enteritis outbreaks (stomach bug)
- Symptoms: vomiting, diarrhea, nausea, cramping
- Virus only lasts 24-72 hours
- 685 million illnesses per year globally (so common)
- Reinfection common
- No vaccine - antigenic drift
11. Trypanosoma brucei - Parasite
- Causes: African trypanosomiasis (sleeping sickness)
- Transmission: African tsetse fly bite (doesn't occur in US)
- Two types: East/West African
- First invades circulation, crosses blood-brain barrier, infects nervous system -> mental
deterioration, sleep disturbances, confusion -> death
- Treatment: medication - relapse common
- No vaccine
- Prevention: cover skin, use repellant
