California REHS examination, REHS Sample Exam
Questions with Detailed Solutions.
Toxin correct answers poisonous substances produced by certain microorganisms.
pathogenicity correct answers the level of damaging effect of microorganisms
Exotoxin correct answers proteins that are produced by certain species of largely Gram-
Positive Bacteria. The bacteria manufacture these proteins as part of their normal metabolism.
These proteins are accumulated within the cytoplasm of the bacteria, then released with waste
products of metabolism.
Neurotoxin correct answers a toxin which inhibits the release of acetylcholine at
neuromuscular junctions
Endotoxin correct answers proteins produced chiefly by Gram-Negative Bacteria. They are
complexes of protein. Polysaccharide and lipid that are part of the bacterial cell wall. They
are released during bacterial disintegration caused by antibiotics or phagocytosis.
innate immunity correct answers Immunity that is present before exposure and effective from
birth. Responds to a broad range of pathogens.
naturally acquired active immunity correct answers develops after exposure to antigens in
environment
artificially acquired active immunity correct answers antibodies are made due to exposure to
a vaccine
naturally acquired passive immunity correct answers antibodies are passed from mother to
fetus via the placenta and breast milk
artificially acquired passive immunity correct answers antibodies gathered from a human or
other animal and are injected into an individual. Ex.) antiserum for a snakebite.
Colorado Tick Fever correct answers Infectious Agent:
Virus
Resevoir:
Rodents including ground squirrels, chipmunks, and wood rats
Mode of Transmission:
Bites from ticks
Symptoms:
Fever, Dengue like disease without a rash
Fatality:
rare
,Control:
Control tick populations. Avoid infested areas. There is no immunization method for this
disease.
Eastern Equine Encephalitis correct answers Infectious Agent:
A viral disease
Resevoir:
Not determined, but potentially birds, rodents, reptiles, amphibians and even mosquitos and
man
Mode of Transmission:
bite from an infected Culiseta melanura mosquito which probably acquired the infection from
wild birds/rodents.
Found in the eastern United States.
Host: Humans and horses
Symptoms:
Mild cases become viral meningitis. Severe infections are usually: headache, high fever,
disorientation, stupor, tremors, occasional convulsions, and paralysis in infants. Incubation
period is 5-15 days
Fatality:
5-60% depending on the type of virus
Control:
Control mosquito populations. Avoid stagnant water. Immunity to this disease is possible for
populations suspect of the disease through mild and less severe former infections. The most
susceptible victims are children. There are vaccines for certain strains, but not all varieties.
St. Louis Encephalitis correct answers Infectious Agent:
A viral disease
Resevoir:
no true reservoir, but potentially birds, adult mosquitos, and man can be a reservoir
Mode of Transmission:
A bite from the Culex Tarsalis and the culex pipes mosquito. These mosquitos acquire the
infection from wild birds.
Host: Humans and horses
Symptoms:
Mild cases become viral meningitis. Severe infections usually exhibit symptoms of headache,
high fever, stupor and disorientation, tremors, occasional convulsions and paralysis in infants.
Incubation period is 5-15 days
Fatality:
,25% for untreated cases.
Control:
Control Mosquito populations. Eradicate larvae
Western Equine Encephalitis correct answers Infectious Agent:
A Viral disease
Resevoir:
not exactly known, but present in birds, rodents, reptiles, amphibians, adult mosquitos, and
man
Mode of Transmission:
the culex tarsalis mosquito. Host: humans and horses
Symptoms:
mild cases become meningitis. Sever infections are headache, fever, stupor, and
disorientation
Fatality:
5-60%
Control:
Mosquito control is most important
West Nile Virus correct answers Infectious Agent:
A viral disease
Resevoir:
No exact reservoir, but birds, rodents, reptiles, amphibians, and adult mosquitos, and man can
be resevoirs
Mode of Transmission:
Cules tarsalis Mosquito. Host: Humans and horses
Symptoms:
Mild Cases become viral meningitis. severe infections usually exhibit symptoms of headache,
high fever, stupor, and disorientation
Fatality:5-60%
Control:
Mosquito Control is most important
Hepatitis A (acute) correct answers Infectious Agent:
Hepatitis A virus (HAV). An entero virus
Reservoir:
Man and primates
, Growth Factors:
temperature range 98.6F
Characteristics
A viral organism
Mode of Transmission:
the common vehicle is water, milk, oyster, and clams near a sewage outfall. The infection can
be caused through contact of water, milk, and food (fecal/oral)
Symptoms:
fatigue, abrupt onset with fever, headaches, malaise, nausea, and abdominal discomfort,
anorexia, vomiting. Jaundice after a couple of days, light colored stools, dark urine, necrosis
of the liver.
1-2 weeks duration.
Fatality:
1 per 1000 cases, 25k-30k cases annually.
Control:
good sanitation, proper hygiene, thorough cooking of food, avoiding shellfish (raw oysters)
from polluted sources.
Hepatitis B virus (HBV) correct answers Infectious Agent:
HBV. Disease obtained from blood products, transfusions, and sharing dirty syringes. Not as
infectious as Hep A.
Reservoir:
Man
Mode of Transmission:
Pre-cutaneous inoculations
Symptoms:
Nausea, abdominal discomfort, vomiting, and finally progressing to jaundice. ranges from
non-detectable symptoms to fatal cases with acute liver failures. Incubation period, 60-90
days average
Fatality:
Fatality rate is 1%
Control:
strict control over syringe usage, and blood product containers should be enforced. Proper
education with drug abusers should be conducted.
Hepatitis C (HCV) correct answers Infectious Agent:
HGV. Disease obtained from blood products. Transfusions and the sharing of dirty syringes.
Reservoir:
Man
Questions with Detailed Solutions.
Toxin correct answers poisonous substances produced by certain microorganisms.
pathogenicity correct answers the level of damaging effect of microorganisms
Exotoxin correct answers proteins that are produced by certain species of largely Gram-
Positive Bacteria. The bacteria manufacture these proteins as part of their normal metabolism.
These proteins are accumulated within the cytoplasm of the bacteria, then released with waste
products of metabolism.
Neurotoxin correct answers a toxin which inhibits the release of acetylcholine at
neuromuscular junctions
Endotoxin correct answers proteins produced chiefly by Gram-Negative Bacteria. They are
complexes of protein. Polysaccharide and lipid that are part of the bacterial cell wall. They
are released during bacterial disintegration caused by antibiotics or phagocytosis.
innate immunity correct answers Immunity that is present before exposure and effective from
birth. Responds to a broad range of pathogens.
naturally acquired active immunity correct answers develops after exposure to antigens in
environment
artificially acquired active immunity correct answers antibodies are made due to exposure to
a vaccine
naturally acquired passive immunity correct answers antibodies are passed from mother to
fetus via the placenta and breast milk
artificially acquired passive immunity correct answers antibodies gathered from a human or
other animal and are injected into an individual. Ex.) antiserum for a snakebite.
Colorado Tick Fever correct answers Infectious Agent:
Virus
Resevoir:
Rodents including ground squirrels, chipmunks, and wood rats
Mode of Transmission:
Bites from ticks
Symptoms:
Fever, Dengue like disease without a rash
Fatality:
rare
,Control:
Control tick populations. Avoid infested areas. There is no immunization method for this
disease.
Eastern Equine Encephalitis correct answers Infectious Agent:
A viral disease
Resevoir:
Not determined, but potentially birds, rodents, reptiles, amphibians and even mosquitos and
man
Mode of Transmission:
bite from an infected Culiseta melanura mosquito which probably acquired the infection from
wild birds/rodents.
Found in the eastern United States.
Host: Humans and horses
Symptoms:
Mild cases become viral meningitis. Severe infections are usually: headache, high fever,
disorientation, stupor, tremors, occasional convulsions, and paralysis in infants. Incubation
period is 5-15 days
Fatality:
5-60% depending on the type of virus
Control:
Control mosquito populations. Avoid stagnant water. Immunity to this disease is possible for
populations suspect of the disease through mild and less severe former infections. The most
susceptible victims are children. There are vaccines for certain strains, but not all varieties.
St. Louis Encephalitis correct answers Infectious Agent:
A viral disease
Resevoir:
no true reservoir, but potentially birds, adult mosquitos, and man can be a reservoir
Mode of Transmission:
A bite from the Culex Tarsalis and the culex pipes mosquito. These mosquitos acquire the
infection from wild birds.
Host: Humans and horses
Symptoms:
Mild cases become viral meningitis. Severe infections usually exhibit symptoms of headache,
high fever, stupor and disorientation, tremors, occasional convulsions and paralysis in infants.
Incubation period is 5-15 days
Fatality:
,25% for untreated cases.
Control:
Control Mosquito populations. Eradicate larvae
Western Equine Encephalitis correct answers Infectious Agent:
A Viral disease
Resevoir:
not exactly known, but present in birds, rodents, reptiles, amphibians, adult mosquitos, and
man
Mode of Transmission:
the culex tarsalis mosquito. Host: humans and horses
Symptoms:
mild cases become meningitis. Sever infections are headache, fever, stupor, and
disorientation
Fatality:
5-60%
Control:
Mosquito control is most important
West Nile Virus correct answers Infectious Agent:
A viral disease
Resevoir:
No exact reservoir, but birds, rodents, reptiles, amphibians, and adult mosquitos, and man can
be resevoirs
Mode of Transmission:
Cules tarsalis Mosquito. Host: Humans and horses
Symptoms:
Mild Cases become viral meningitis. severe infections usually exhibit symptoms of headache,
high fever, stupor, and disorientation
Fatality:5-60%
Control:
Mosquito Control is most important
Hepatitis A (acute) correct answers Infectious Agent:
Hepatitis A virus (HAV). An entero virus
Reservoir:
Man and primates
, Growth Factors:
temperature range 98.6F
Characteristics
A viral organism
Mode of Transmission:
the common vehicle is water, milk, oyster, and clams near a sewage outfall. The infection can
be caused through contact of water, milk, and food (fecal/oral)
Symptoms:
fatigue, abrupt onset with fever, headaches, malaise, nausea, and abdominal discomfort,
anorexia, vomiting. Jaundice after a couple of days, light colored stools, dark urine, necrosis
of the liver.
1-2 weeks duration.
Fatality:
1 per 1000 cases, 25k-30k cases annually.
Control:
good sanitation, proper hygiene, thorough cooking of food, avoiding shellfish (raw oysters)
from polluted sources.
Hepatitis B virus (HBV) correct answers Infectious Agent:
HBV. Disease obtained from blood products, transfusions, and sharing dirty syringes. Not as
infectious as Hep A.
Reservoir:
Man
Mode of Transmission:
Pre-cutaneous inoculations
Symptoms:
Nausea, abdominal discomfort, vomiting, and finally progressing to jaundice. ranges from
non-detectable symptoms to fatal cases with acute liver failures. Incubation period, 60-90
days average
Fatality:
Fatality rate is 1%
Control:
strict control over syringe usage, and blood product containers should be enforced. Proper
education with drug abusers should be conducted.
Hepatitis C (HCV) correct answers Infectious Agent:
HGV. Disease obtained from blood products. Transfusions and the sharing of dirty syringes.
Reservoir:
Man
