Midterm 1: General Epidemiology (Topic 1-4) Flashcards
(279 cards)
1
Q
Veterinarians can cause iatrogenic infections
A
True
2
Q
Arthropod borne infections are direct infections
A
False (indirect)
3
Q
Arthropod borne infections are indirect infections
A
True
4
Q
Venereal infections are direct infections
A
True
5
Q
Drinking water cannot transmit infective agents as it is hypoosmotic
A
False (water can be a source of indirect infection)
6
Q
In direct infections, tissue of the infected agent become in contact with the tissues of the host
A
True
7
Q
In the case of aerogenic infections, the agent is transmitted by air
A
True
8
Q
Aerogenic infection is a form of direct infection
A
False (indirect)
9
Q
Infections cannot survive in the soil, so the soil cannot be a source of infection
A
False (soil is a source of indirect infection)
10
Q
The arthropod is a true vector if it brings the pathogen into a susceptible animal
A
False (enters, colonises, replicates within host)
11
Q
The arthropod is a true vector if it replicates/propagates within the host
A
True
12
Q
The arthropod is a true vector if it can take the pathogen to a further distance
A
False
13
Q
Infection cannot happen through water since the bacteria and viruses are inactivated in water
A
False (water is a source of indirect infection)
14
Q
Meat is never involved in transmission of infections since fermentation of meat kills agents
A
False (animal products are a source of indirect infection)
15
Q
Some infectious agents are transmitted with eggs
A
True
16
Q
Germinative infection is more frequent in birds than mammals
A
True
17
Q
Germinative infection is very frequent in mammals
A
False (rare in mammals, frequent in birds)
18
Q
Germinative infections do not occur in mammals
A
False (occur but is rare)
19
Q
Mammals can infect their offspring through milk
A
True
20
Q
Newborn animals cannot be infected from the milk thanks to colostral antibodies
A
False (milk is a source of vertical infection - galactogenic)
21
Q
Intrauterine infection occurs if the foetus is infected while in the uterus of the dam
A
True
22
Q
Vertical infection does not occur in mammals
A
False (intrauterine, galactogenic and rarely germinative)
23
Q
Horizontal infections can only occur in birds
A
False
24
Q
Germinative infection is frequent in mammals and will result in malformation of the foetus
A
False (rare in mammals)
25
In horizontal infection, animals of the same group infect each other
True
26
Intrauterine infections can occur in pregnant animals
True
27
Germinative infections can happen in birds
True
28
Galactogenic infection is a form of horizontal infection
False (vertical = germinative, intrauterine, galactogenic)
29
If the dam infects the newborn, we speak of horizontal infection
False (this is germinative - vertical = germinative, intrauterine, galactogenic)
30
Galactogen infections are spread via the milk
True
31
In horizontal spreading of an infection, the agent is spread between animals of similar age group
True
32
Horizontal infection does not occur in mammals
False
33
Vertical infection does not occur in mammals
False (vertical = galactogenic, intrauterine and rarely germinative in mammals)
34
Galactogenic infection does not occur in mammals
False
35
In germinative infection, the placenta is infected by the mother during pregnancy
False (? this is intrauterine)
36
Germinative infection is rare in mammals and is a form of horizontal infection
False (rare in mammals but is vertical)
37
Zoonotic agents can cause infection in animals and humans
True
38
In cyclozoonosis, arthropods are responsible for maintaining the infection
False (they spread it, host maintains it)
39
If humans infect animals we speak of metazoonosis
False (metazoonosis requires a vertebrate and an invertebrate)
40
Cyclozoonosis requires an arthropod for transmission
False (arthropod begins infection, the cycle of the host transmits/maintains it)
41
In zoonosis, humans and animals can infect each other
True (e.g. tuberculosis can transmit human to animal)
42
In saprozoonosis, animals and humans are infected by the same source
True (agent can infect animals and humans from the environment e.g. Erysipelas from the soil)
43
In secondary infection, a bacterium infects an individual already infected with a pathogen
True (e.g. respiratory infection damages mucosa and allows bacteria to culture)
44
In secondary infection, a new pathogen infects a cured animal
False (single infection??)
45
In secondary infection, two pathogens infect the host simultaneously
False (mixed infection)
46
In secondary infection, one agent is always a virus
False (usually but not always)
47
Facultative pathogenic agents are helped by predisposing factors
True
48
Stenoxen agents have a wide host range
False (narrow host range, wide = euryxen)
49
Euyxen have a narrow host range
False (wide host range, stenoxen = narrow)
50
There is no minimum number of agents required for infection as they can replicate in the host
False (bacillus anthracis needs more to infect dogs than it does sheep)
51
Mutations generally result in decrease in virulence
True (natural spontaneous decraese)
52
Immunogenicity of different agents vary
True
53
Virulence can be characterised by LD50
True (and MLD)
54
Pathogenicity is the ability of an agent to cause disease
True
55
Virulence is the grade of pathogenicity
True
56
In optimal route of infection, the minimum amount of agent can cause disease
True
57
Virulence of an agent is connected to the virulent factors
True
58
Virulence is a stable characteristic
False (Can naturally decrease via mutations, can artificially decrease for vaccines, can naturally increase)
59
Route of infection can influence the outcome
True (tetanus does not usually cause infection if ingested but can if enters a wound)
60
Virulence can change spontaneously
True
61
In secondary infection, the pathogen complicated the primary infection
True
62
Virulence factors help the agent cause disease
True
63
Pathogenic variants can occur between agents
True
64
Species specific resistance can be overcome by increasing the number of agents
False
65
Within a pathogenic species, no avirulent strains can occur
False (this is how we create vaccines)
66
Foetuses can have an active immune response
True
67
Newborn animals can have a local immune response
True
68
The skin, mucous membranes are part of the non-specific resistance of the host
True (as well as bile and acidic pH of the stomach)
69
The normal microflora of the gut is essential for animals, they cannot live without it
False (not harmful but also not beneficial for the host - example of commensalism)
70
Foetuses have no immune response, it appears in 2-4 week old animals
False
71
The age of an animal does not influence their susceptibility to a disease
False (some affect only young)
72
Certain medicines can decrease the protection of the host
True (immunosuppressives)
73
Species specific resistance means that certain agents cannot infect certain hosts
True (?? Not sure)
74
Species specific resistance means that certain agents cannot infect certain resistant hosts
True
75
Animals cannot be infected with certain agents if they have species specific resistance
True
76
Certain animal species are resistant against certain agents
True
77
Chicken embryos are able to produce an immune response
True (germinative immunity from hen)
78
Cellular immune response is important in the case of viruses
True (viruses do not have their own metabolism so they infect intracellularly so that they can replicate via dividing cells)
79
Gastric juice can protect hosts from pathogens
True (non-specific immunity)
80
From the 2nd trimester of pregnancy, the foetus produces an immune response against any antigen
False
81
There is no immune response in the foetus, only from 2-4 weeks of age
False (mother passes on intrauterine vertical immunity)
82
Unfavourable environmental effects can predispose animals to diseases caused by facultative pathogens
True (facultative pathogens require a predisposition)
83
Nutrition of the animal can influence the appearance of infection
True
84
Mycotoxins can be immunosuppressive
True
85
Overcrowding can help the spread of infection
True (as well as ammonia in the environment, bad stabling, poor ventilation)
86
Deserts can inhibit the spread of disease
True (as well as rivers, islands and mountains)
87
Viruses causing generalised diseases generally replicate at the site of entry and at the regional lymph node
True (exceptions like papilloma virus = skin, rotavirus = gut)
88
The lesions are at the place of entry of local infections
True
89
Lesions can be seen in different organs in generalised infections
True
90
Intrauterine immunity can lead to immunotolerance in some cases
True (antibodies passed to foetus before own immunity develops i.e. recognise antigens as own cells)
91
Intrauterine infection can result in embryonic death in some cases
True (??)
92
Intrauterine infection does not occur due to the protection of the placenta
False
93
Incubation time is between clinical signs and death
False (between infection and clinical signs)
94
Seroconversion time is between infection and clinical signs
False (this is incubation time. Seroconversion time is between infection and immune response - longer than incubation time)
95
Some infection agents can cause malformation of the foetus
True
96
Subacute diseases last for 1-2 days
False (acute)
97
In the case of generalised infections, the agent is usually spreading through the blood
True (blood and lymph nodes - viraemia, bacteraemia, septicaemia)
98
Some agents can spread along the nerves
True (rabies)
99
The agent does not replicate in dead hosts
False
100
Dead end hosts show no clinical signs, die without signs
False (show signs but do not pass on the agent, infection dies with them)
101
In a latent infection, the agents are continuously shed
False (only if triggered by a stress to manifest)
102
Latent infection occurs when the genome of the agent is integrated into the genome of the host
True
103
In latent infection, there is no virus shedding
False (spreads once manifested??)
104
Abortion is the main clinical sign of abortive infections
False (abortive infection is when the host gets rid of the infection)
105
The animal does not carry the agent once recovered from an infectious disease because the immune system eliminates it
False
106
Tolerated infections result in a high level of immune reactions
False (there is no immune reaction because the body mistakes antigen as own cells)
107
Infection before self-recognition of the immune system can lead to tolerated infections
True
108
Infected animals have a high amount of antibodies in the case of tolerated infection
False (they have none)
109
The agent is not shed in inapparent infections
False (no clinical signs but can be manifested)
110
Dead end hosts do not shed the agent
True
111
Asymptomatic infections can manifest clinical signs
True
112
Formation of immune complexes can be a result of persistent infections
True
113
When the clinical signs disappear, shedding of the agent finishes
False
114
In abortive infections, no clinical signs will be seen
False
115
In latent infections, only mild clinical signs will be seen
False
116
Animals with tolerated infections shed the agent
True
117
Only animals with clinical signs can shed the agent
False
118
No clinical signs are seen in inapparent infections
True
119
Latent infections are common in gram-positive bacteria
False (??)
120
In inapparent infections, seropositivity can be seen
True (agent in the blood)
121
Inapparent infections cannot be seen in laboratory examinations
False
122
In abortive infections, the animal always aborts
False
123
In subclinical infections, the animal can shed the agent
True
124
Tolerated infections can be seen in serology
False (cannot be detected, difficult diagnosis)
125
Abortive infections can be demonstrated by serology
True
126
In a tolerated infection, the animal is seropositive
False
127
In latent infections, no clinical signs will be seen
False
128
Asymptomatic infections can be manifested
True
129
Mortality is the percentage of dead animals in a herd
True
130
Mortality shows the number of diseased animals that die
False (this is lethality)
131
Morbidity is the percentage of dead animals in a herd
False (this is mortality, morbidity is the number of diseased animals in a herd)
132
Lethality shows the percentage of animals that show clinical signs and die
True
133
Prevalence shows the number of diseased animals compared to the total number of a herd
False (this is mortality, prevalence is the number of existing cases of infection in a herd at one time)
134
Monitoring is routine collection of data on a disease
True
135
Pandemic is the fast spread between continents
True
136
Pandemic diseases spread fast throughout Earth
True
137
Endemic diseases occur in smaller limited areas like farms or villages
True
138
Pandemic cases do not tend to spread
False
139
Epidemic cases are spread throughout larger areas, between countries
True
140
Contagious diseases are spread from one animal to another
True
141
Hemagglutination inhibition test is used for the detection of antigens of certain agents
False (it is indirect detection of the antibodies - serological test)
142
Genome of agents is tested with PCR
True
143
Antigens of agents can be tested with PCR
False (antigens tested with immunofluorescence, ELISA, electrophoresis, immunoblots, direct HA)
144
Surface antigens of certain agents are detected with ELISA and PCR
False
145
Infective agents can be detected 2-3 days after infection using serological tests
False
146
Virus neutralisation tests detect the antigen of a virus
False (indirect detection of antibodies - serological test)
147
Serological tests are used for the detection of antibodies
True
148
MATSA is used in laboratory diagnosis
True
149
MATSA is a form of disease
False
150
Microscopic detection of agents is not used in diagnostic work anymore
False
151
If an animal is infected, laboratory tests always detect the antigen
False
152
The phase of pathogenicity can influence the sensitivity of laboratory tests
True
153
Using virus neutralisation tests, we detect the antibody
True
154
Polymerase chain reaction is used for the detection of antigen of the agent
False (genome of the agent is detected)
155
Post mortem lesions aid in the setting up of diagnosis
True
156
Epidemiological data can help in preliminary diagnosis
True
157
Antibacterial treatments are banned in the EU against viruses
False (can be used for secondary infection)
158
Individual and mass treatment can be combined in some cases of infections
True
159
Hyperimmune serum can be used in some aetiological treatment of certain diseases
True
160
No aetiological treatment available for virus infections
False
161
Mass treatment using antibiotics is banned in the EU
False
162
Antibiotics can be used for bacterial infections
True
163
All bacterial agents can be eradicated by antibiotics
False
164
Antibacterial treatment is used in the case of viral diseases in order to prevent bacterial complications
True
165
Using antibiotics with viral infections is not allowed due to resistance
False
166
Treatment of certain infectious diseases is prohibited
True
167
Symptomatic treatment is recommended because it can support the healing of an animal
True
168
Antibiotics may only be used until the disappearance of clinical signs
False
169
Only diseased animals have to be treated with antibiotics to avoid resistance
False
170
Using hyperimmune serum is usually unjustifiable
True
171
In case of importing animals to a farm, animals in quarantine must be tested for infections
True
172
In case of importing animals to a farm, animals in quarantine must only be observed for clincial signs
False
173
Only eggs from the same flock can be hatched in one hatching machine
True
174
Eggs of different species can be hatched together, they do not infect each other due to different hatching times
False
175
All-in-all-out is important in disease prevention
True
176
Isolation of age groups is important in disease prevention
True
177
Isolation of similar age groups does not prevent infection as all animals of the same species are prone to all infections
False
178
Day old birds cannot be infected in the hatchery because they are protected by yolk immunity
False
179
The immunoglobulin content of the colostrum is continuously decreasing after farrowing
True
180
Maternal antibodies can inhibit active immune response
True
181
There is no maternal protection in birds
False
182
Colostrum is the main method of protection in animals with epitheliochorial placenta
True
183
The half-life of the heterologous hyperimmune serum is about 7-10 days
True
184
The half-life of the heterologous hyperimmune serum is about 2-3 weeks
False (homologous)
185
Animals having epitheliochorial placenta receive maternal antibodies only through the placenta
False
186
Animals having epitheliochorial placenta receive maternal antibodies only through the colostrum
True
187
Enteral lymphocytes of the dam can be transferred to the offspring in colostrum
True
188
The immunoglobulin content of the colostrum is influenced by the nutrition of the dam
True
189
The protein and antibody content of the colostrum is stable in the first week after calving
False
190
Absorption of maternal antibodies from the colostrum in the first three days is not changing
False
191
Colostrum is not important in protection of calves since the antibodies can go through the placenta
False
192
Colostrum is the only way of receiving maternal protection in calves
True
193
The immunoglobulin content of the colostrum is not changed in the first week after birth
False
194
Calves can absorb maternal antibodies for a week after birth
False
195
Maternal antibodies can inhibit certain immunisation
True
196
New-born animals cannot be infected from the milk thanks to the colostral antibodies
False
197
The colostrum contains maternal lymphocytes
True
198
The protein content of the colostrum remains high for the first two weeks after giving birth
False
199
The immune globulin content of the colostrum remains high for the first week after giving birth
False
200
The enteral absorption of immune globulins is decreasing after birth
True
201
Maternal antibodies can decrease the efficacy of vaccination
True
202
The immune globulin concentration of the colostrum decreases sharply after birth
True
203
The enteral absorption of immunoglobulins is about the same for a week after birth
False
204
The maternal antibodies can decrease the immune response against vaccines
True
205
Enteral lymphocytes can get from the dam to the newborn animal with colostrum
True
206
The endotheliochorial placenta prevents the transport of immunoglobulins to the foetus
False
207
Homologous hyperimmune serum can provide about a year-long protection
False
208
Strains used in marker vaccines can be differentiated from the field strains
True
209
Avirulent strains can be used in live vaccines
True
210
The health state of the vaccinated animals can influence the efficacy of the vaccination
True
211
Adjuvants in vaccines increase the shelf life of vaccines
False
212
Inactivated vaccines contain inactivated bacterial toxins
True
213
The method of vaccination has no effect on the efficacy of the vaccination
False
214
Adjuvants in vaccines increase the efficacy of vaccines
True
215
Attenuated strains can be used in live vaccines
True
216
Deletion vaccines can only be used as live vaccines
False
217
Inactivated vaccines can contain the whole agents or their components
True
218
The colostral immunoglobulins have no effect on the vaccination of the newborn animals
False
219
DIVA principle can only be used if the animals are vaccinated with deletion vaccines
False
220
According to DIVA principle, infected and vaccinated animals can be differentiated
True
221
Subunit vaccines contain only antigens of the agents
True
222
Certain parts of the genome are missing from deletion vaccine strains
True
223
Some genes are missing from the strains included in deletion vaccines
True
224
For safety reasons only inactivated vaccines are used
False
225
Live vaccines can contain strains with lower virulence
True
226
Live vaccines always contain avirulent agents
False
227
Live vaccines are less effective than the inactivated ones
False
228
Live vaccines are dangerous, they are not on the market any more
False
229
Live vaccines are not used in Europe any more
False
230
Live vaccines do not provide good immunity
False
231
Marker vaccines are used to mark the site of vaccination
False
232
It is not allowed to use inactivated deletion vaccines in the EU
False
233
Live vaccines contain attenuated or avirulent agents
True
234
The agent in a vaccine can influence the level of the immune response of vaccinated animals
True
235
If deletion vaccines are used, vaccinated and infected animals can be differentiated
True
236
Using marker vaccines, vaccinated and infected animals can be differentiated
True
237
Use of marker vaccines can be combined with test and remove eradication
True
238
Marker vaccines are marked with dyes
False
239
The immune response produced by an attenuated vaccine is low
False
240
Some attenuated vaccine strains can be immunosuppressive
True
241
Attenuated vaccines induce a quick immune response
True
242
Vaccines containing attenuated strains are not used anymore
False
243
The amount of antigen in the vaccine has no effect on the efficacy of the vaccine
False
244
Eradication with selection method is not done nowadays
False
245
Newborn animals must be kept isolated when eradication with generation shift is used
True
246
Eradication with generation shift cannot be used if the level of infection is high in the herd
False
247
Eradication using generation shift method is mainly used in Poultry
False
248
Implantation of washed embryos from a non infected dam into infected one is a way of eradication
False
249
Implantation of washed embryos from a infected dam into non-infected one is a way of eradication
True
250
Eradication using the generation shift method is mainly used in pig herds
False
251
In the case of generation shift the infected animals must be slaughtered at the beginning of the eradication procedure
False
252
Eradication using selection method can be combined with vaccination
True
253
In the case of generation shift the young animals must be isolated from the dam at the age of 1-3 days
True
254
Eradication using the selection method is generally implemented in case of low level of infection
True
255
When eradication is made with selection method, the infected animals are removed from the herd
True
256
Selection, generation shift and herd replacement can be used for eradication
True
257
Eradication using generation shift can be used in cattle herds
True
258
Caesarean section is the only way of birth when eradication is carried out using the SPF method
False
259
Certain diseases can be eradicated with generation shift
True
260
Herd replacement is the cheapest way of eradication of a disease
False
261
Selection (test and slaughter) is a method of eradication of a disease
True
262
Selection method can be used for eradication of infectious diseases, when we remove infected animals
True
263
In the case of generation shift, newborn animals are separated from the dam and kept isolated
True
264
Embryo transfer cannot be used for eradication, since the embryo can be infected
False
265
The selection method cannot be combined vaccination
False
266
Test and slaughter as an eradication method can be used in case of low level of infection
True
267
There is no agent which can be eradicated by antibiotic treatment
True
268
In the case of generation shift newborn animals have to be kept isolated from the parent animals
True
269
In the case of herd replacement, the herd is replaced with infection-free animals
True
270
In the case of selection method of eradication the infected animals are taken out of the herd
True
271
If eradication is made by selection method, vaccination is forbidden
False
272
Early weaning is necessary if generation shift method of eradication is used
True
273
Generation shift is a frequently used eradication method in swine
False
274
Generation shift is a method of eradication of a disease
True
275
In eradication by selective breeding, the seropositive animals are eliminated
True
276
In eradication by selective breeding, only the animals shedding the bacteria are eliminated
False
277
In eradication by selective breeding, vaccination cannot be used
False
278
Eradication by selective breeding is not used anymore
False
279
Selection (test and remove) is not used to eradicate a disease anymore
False
