General Epidemiology Flashcards
Veterinarians can cause iatrogenic infections.
T
Arthropod borne infections are direct infections
F
Arthopod born infections are indirect infections
T
Arthropods can be involved in indirect infections.
T
Venereal infections is a direct infection
T
In the case of iatrogenic infections the infective agents are transmitted by the
veterinarian
T
Drinking water cannot transmit infective agents since it is hypoosmotic
F
In case of direct infection tissues of the infected animal are contacted with tissues of the
host
T
In the case of aerogenic infection the agents are transmitted with air.
T
Aerogenic infection is a form of direct infection
F
In the case of aerogenic infection the agent is transmitted by the air.
T
Infective agents cannot survive in the soil, so soil cannot be a source of infection
F
In the case of iatrogenic infection the agent is transmitted by humans
T
Direct infection happens when infected animals pass the infection with water
F
If the arthropod is a true vector, if it brings the pathogen into a susceptible animal
F
The arthropod is a true vector, if the pathogen also replicates in the susceptible animal
T
False?
The arthropod is a true vector, if it propagates the pathogen
T
The arthropod is a true vector, if it can take the pathogen to a further distance
F
Infection cannot happen through water since bacteria and viruses are inactivated in
water.
F
Meat is never involved in transmission of infections since fermentation of meat kills
agents
F
Some infective agents are transmitted with eggs
T
Germinative infection is more frequent in birds than in mammals.
T
Germinative infection is very frequent in mammals
F
Germinative infection is seen in mammals
T
Mammals can infect their offspring through milk
T
New-born animals cannot be infected from the milk thanks to the colostral antibodies
F
Intrauterine infection happens if the foetus is infected during pregnancy from the dam
T
Vertical infection does not occur in mammals
F
Horizontally infections happen only in birds
F
Germinative infection is frequent in mammals, it will result in malformation of the
foetuses
F
Galactogen infection cannot happen when the animals receive colostrum, since the
antibodies in the colostrum prevent it
F
In the case of horizontal infection animals in the same group infect each other.
T
Intra uterine infection can occur in pregnant animals.
T
Germinative infection can happen in birds.
T
Galactogen infection is a form of horizontal infections.
F
If the dam infects newborn animals, we speak about horizontal infection
F
Germinative infection can occur mainly in mammals.
F
In the case of galactogen infection the agent is transmitted by milk
T
In the case of horizontal infection the agent is spreading between animals of about the
same age
T
Horizontal infection does not occur in mammals
F
Vertical infection does not occur in mammals.
F
Germinative infection does not occur in mammals.
F
Galactogen infection does not occur in mammals
F
In germinative infection, the placenta is infected by the mother during pregnancy
F
Germinative infection is a rare form of horizontal infection
F
In germinative infection, the newborn is infected through the milk.
F
Zoonotic agents can cause disease in animals and humans
T
In the case of cyclozoonoses arthropods are responsible for maintaining the infections
F
If agents are passed from animals to humans, we speak about zoonosis
T
If humans infect animals we speak about metazoonoses.
F
Cyclozoonoses require an arthropod for transmission
F
In the case of zoonotic diseases animals and humans can infect each other
T
In the case of saprozoonoses animals and humans are infected from the same source.
T
In case of secondary infection, a bacterium infects an individual, which is already infected with a pathogen.
T
In case of secondary infection, a new pathogen infects an already cured animal
F
In case of secondary infection, two pathogens infect the host simultaneously
F
In case of secondary infection, one of the agents is always a virus
F
Facultative pathogenic agents are helped by predisposing factors
T
Stenoxen agents have a wide host range
F
Euryxen agents have a wide host range
T
An euryxen agent can infect several host species
T
There is no minimum number of agents necessary to infection, because they can
replicate in the host
F
Mutations generally result decrease of the virulence
T
Immunogenicity of the different agents is different
T
There is a minimum number of each agent that is necessary to infect animals
T
A minimum amount of bacteria or viruses is needed to a successful infection
T
Virulence of an agent can be characterized with its LD50 value
T
Pathogenicity means the ability of the agent to cause disease
T
Virulence means the level of pathogenicity.
T
The amount of the agent does not influence the outcome of the infection, since it can
replicate in the host
F
In the case of optimal way of infection the least amount of agent can cause disease
T
The virulence of the agents is connected to virulence factors
T
Virulence is a stable characteristic of an agent.
F
The way of the infection (entrance of the agents) can influence its outcome
T
Virulence of a bacterium or virus can be changed spontaneously
T
In case of a secondary infection the agent complicates a primary infection.
T
Virulence of a bacterium or virus can be changed
T
The virulence factors help the agents in causing disease.
T
Virulence variants can occur within a bacterium or virus species
T
Pathogenic variants can occur within a bacterium or virus species
T
Species specific resistance can be overcome by increasing the number of agents
F
Within a pathogenic species no avirulent strains can occur.
F
Foetuses can have active immune response
T
Newborn animals have local immune response
T
Foetuses do not have immune reactions
F
Fetuses have no active immune response
F
The skin, mucous membranes and mucous are parts of the non specific resistance
system of the host
T
The normal microflora of the gut is essential for animals; they cannot live without it
F
Foetuses have no immune response; they appear only in 2-4 week old animals
F
The age of the animals does not influence their susceptibility to a certain agent
F
Susceptibility to a disease can be influenced by age
T
Certain medicines and agents can decrease the protection of the hosts
T
Species specific resistance means that certain agents cannot infect certain hosts
T
Species related resistance means that certain agents cannot cause infection in resistant
host species.
T
Animals cannot be infected with certain agents if they have species specific resistance.
T
Certain animal species are resistant against certain agents
T
Chicken embryos are able to produce an immune response
T
Cellular immune response is very important in the case of viral diseases
T
Gastric juice can protect the host from infections
T
From 2nd trimester of pregnancy, the foetus produces an immune response against any antigen.
F
There is no immune response in the foetus, only from 4 weeks after birth.
F
Unfavourable environmental effects can predispose animals to diseases caused by facultative pathogenic agents.
T
Nutrition of the animals can influence the appearance of infectious diseases
T
Environmental effects can influence the survival of the agents in the environment
T
Mycotoxins can suppress the activity of the immune system
T
Certain mycotoxins have immune suppressive effect
T
Overcrowding can help the spreading of several infectious diseases
T
Deserts can inhibit the spreading of several infectious diseases.
T
Viruses causing generalised diseases generally replicate at the place of entry and in the regional lymph nodes
T
The lesions are at the place of entry of the agent in the case of local infections
T
In the case of a local infection the site of entry and the lesions are at the same place
T
Lesions can be seen in different organs in the case of generalised diseases
T
Intra uterine infection can result immune tolerance in the case of some diseaseS
T
Intra uterine infection can result embryonic death in the case of some diseases
T
Intra uterine infection does not occur since the placenta protects the foetus
F
Fetuses cannot be infested since the placenta completely isolates them
F
The incubation time is the time between the appearance of the clinical signs and death
of the animal
F
The incubation time is the time between infection and the appearance of clinical signs
T
The incubation time lasts from the infection till the manifestation of the clinical signs
T
Some infective agents have immunosuppressive effect
T
Some infective agents can cause malformation of fetuses
T
Subacute diseases last one or 2 days.
F
Intra uterine infections does not occur in mammals since the agents cannot penetrate
the placenta
F
In the case of local infections the lesions can be seen at the site of entry
T
In the case of generalised infections the agent is generally spreading with blood.
T
In the case of generalised infections the placenta prevents the infection of the foetus
F
Some agents can spread along the nerves.
T
The agent does not replicate in dead end hosts
F
Dead end hosts do not show clinical signs, they die without signs
F
In the case of latent infection the agents are continuously shed
F
Latent infection happens when the genome of the agent is integrated in the genome of
the host
T
