Bordetella pertussis: Clinical manifestations and diagnosis

Bordetella pertussis: Clinical manifestations and diagnosis

Q. 1 The following are true for Bordetella pertussis, EXCEPT:

 A

It is a strict human pathogen

 B

It can be cultured from the patient during catarrhal stage

 C

It leads to invasion of the respiratory mucosa

 D

Infection can be prevented by a acellular vaccine

Q. 1

The following are true for Bordetella pertussis, EXCEPT:

 A

It is a strict human pathogen

 B

It can be cultured from the patient during catarrhal stage

 C

It leads to invasion of the respiratory mucosa

 D

Infection can be prevented by a acellular vaccine

Ans. D

Explanation:

Whole cell vaccine was effective but had side effects.

 Acellular vaccines are purified preparations.
 Acellular pertussis vaccines contain inactivated pertussis toxin which may provide protection against disease but not prevention against infection.
It can create career form in adults which can affect the infants.

Immunization reduces disease but outbreaks continue
 
Ref: Textbook of Microbiology By Ananthanarayan and Panicker, 5th Edition, Page 314

Q. 2

A 5-year old child developed seizures a few months ago. The seizures start with feeling of strange smell (burning rubber), continue with generalized contractions, and end with rhythmic spasms. Consciousness is lost during attacks and the child is confused afterwards. When the seizures started, the child was referred to a neurologist who prescribed phenytoin as the initial treatment. Now, the parents bring the child back for scheduled DTP immunization (diphtheria, tetanus, pertussis). Which of the following is the most appropriate next step in the management?

 A

Immunization with DTP vaccine.

 B

Change medication to phenobarbital and DTP immunization

 C

Two weeks drug holiday and DTP immunization afterwards

 D

Deferral of DTP immunization

Q. 2

A 5-year old child developed seizures a few months ago. The seizures start with feeling of strange smell (burning rubber), continue with generalized contractions, and end with rhythmic spasms. Consciousness is lost during attacks and the child is confused afterwards. When the seizures started, the child was referred to a neurologist who prescribed phenytoin as the initial treatment. Now, the parents bring the child back for scheduled DTP immunization (diphtheria, tetanus, pertussis). Which of the following is the most appropriate next step in the management?

 A

Immunization with DTP vaccine.

 B

Change medication to phenobarbital and DTP immunization

 C

Two weeks drug holiday and DTP immunization afterwards

 D

Deferral of DTP immunization

Ans. D

Explanation:

This child has typical tonic-clonic (grand mal) seizures which start with aura. The usual killed, whole-bacterial pertussis vaccine can cause high fever and convulsions. Pertussis vaccination can complicate the already apparent abnormalities and their management. Consequently, deferral of diphtheria, tetanus, pertussis immunization is appropriate. Immunization with DTP or pertussis vaccine and drug holiday can seriously backfire. 

 

 

 

Ref: Ogle J.W., Anderson M.S. (2012). Chapter 42. Infections: Bacterial & Spirochetal. In W.W. Hay, Jr., M.J. Levin, R.R. Deterding, J.J. Ross, J.M. Sondheimer (Eds), CURRENT Diagnosis & Treatment: Pediatrics, 21e. 

 


Q. 3

Acellular pertusis vaccine contains-(

 A

Pertactin, flagillary hemagglutinin, cytotoxin, endotoxin

 B

Pertactin, flagillary hemagglutinin, fimbriae, endotoxin

 C

Pertactin, cytotoxin, fimbriae, pertusis toxin

 D

Flagillary hemagglutinin, pertusis toxin, fimbriae

Q. 3

Acellular pertusis vaccine contains-(

 A

Pertactin, flagillary hemagglutinin, cytotoxin, endotoxin

 B

Pertactin, flagillary hemagglutinin, fimbriae, endotoxin

 C

Pertactin, cytotoxin, fimbriae, pertusis toxin

 D

Flagillary hemagglutinin, pertusis toxin, fimbriae

Ans. D

Explanation:

Ans. is ‘d’ i.e., Flagillary hemagglutinin, pertussis toxin, fimbrial 

.       Acellular pertussis vaccines currently available from different manufactures should be considered as different and unique products because of the presence of one or more different components which are:

Chemically or genetically detoxified pertussis toxin (PT toxoid).

–       Filamentous hemagglutinin

–       69k Da outer membrane protein ( also known as pertactin).

–       Fimbrial-2 and fimbrial-3 antigens.


Q. 4 Whooping cough is caused by

 A

B. pertussis

 B

H. influenzae

 C

Pneumococcus

 D

Meningococcus

Q. 4

Whooping cough is caused by

 A

B. pertussis

 B

H. influenzae

 C

Pneumococcus

 D

Meningococcus

Ans. A

Explanation:

Ans. is ‘a’ i.e., B. pertusis 

  • Whooping cough (also called pertussis) is caused by Bordetella pertussis.

Q. 5 Pertusis affects which age –

 A

2-3

 B

<5

 C

5-7

 D

> 10 years

Q. 5

Pertusis affects which age –

 A

2-3

 B

<5

 C

5-7

 D

> 10 years

Ans. B

Explanation:

Ans. is ‘b’ i.e., < 5 

o In prevaccine era, and in countries where immunization is limited the peak incidence of pertussis is in children 1-5 years of age, infant accounts for < 15% of cases.

o In recent years, where vaccination is employed, approximately one half of cases have occuured in infants younger than 1 year of age and one fourth in adolescent and adults.


Q. 6

All are features of Pertussis except-

 A

Encephalopathy

 B

Cerebellar Ataxia

 C

Subconjunctival hemorrhage

 D

Bronchiectasis

Q. 6

All are features of Pertussis except-

 A

Encephalopathy

 B

Cerebellar Ataxia

 C

Subconjunctival hemorrhage

 D

Bronchiectasis

Ans. B

Explanation:

Ans. is ‘b’ i.e., Cerebellar ataxia

Complications of Pertussis

o Respiratory –

o Patchy Atelatasis

 Subcutaneous emphysema

o Neurological

Persistent seizures

  • Paraplegia                                   
  • Ataxia

o Gasro Intestinal manifestation —> Hernia & Rectal Prolapse

o Hemorrhagic —> Subconjuctival hemorrhage, Intracranial hemorrhage

o Severe malnutrition

o Although ataxia is seen in Pertusis, it is not of cerebellar origin. There is no involveoment of cerebellum in Pertusis (can you find any signs of cerebellar involvement in this pt. ie. Hypotonia, Intentional tremors. Nystagmus, scanning speech)

o It is sensory ataxia.


Q. 7

A child with complaints of cough. Characteristic inspiratory whoop. Sample for investigation is ‑

 A

Nasopharyngeal swab

 B

Tracheal aspiration

 C

Cough plate culture

 D

Sputum culture

Q. 7

A child with complaints of cough. Characteristic inspiratory whoop. Sample for investigation is ‑

 A

Nasopharyngeal swab

 B

Tracheal aspiration

 C

Cough plate culture

 D

Sputum culture

Ans. A

Explanation:

Ans. is ‘a’ i.e., Nasopharyngeal swab 
“Culture of nasopharyngeal secretion remains the gold stadard for diagnosis of whooping cough”


Q. 8

A child presents with recurrent bouts of severe cough followed by an audible whoop. Which of the following is considered the best type of specimen to isolate the organism and confirm the diagnosis.

 A

Nasopharyngeal swab

 B

Cough plate

 C

Throat Swabs

 D

Anterior Nasal Swab

Q. 8

A child presents with recurrent bouts of severe cough followed by an audible whoop. Which of the following is considered the best type of specimen to isolate the organism and confirm the diagnosis.

 A

Nasopharyngeal swab

 B

Cough plate

 C

Throat Swabs

 D

Anterior Nasal Swab

Ans. A

Explanation:

Ans is ‘a’ i.e., Nasopharyngeal swab 

o Presence of recurrent bouts of severe cough followed by an audible whoop suggests a diagnosis of pertusis (Whooping cough).

o Nasopharyngeal Swab is the single best specimen to isolate the organism from the options provided.


Q. 9 The antibiotic of choice of pertussis is –

 A

Ampicillin

 B

Gentamicin

 C

Erythromycin

 D

Penicillin

Q. 9

The antibiotic of choice of pertussis is –

 A

Ampicillin

 B

Gentamicin

 C

Erythromycin

 D

Penicillin

Ans. C

Explanation:

Ans. is ‘c’ i.e., Erythromycin 
Treatment of pertussis

DOC                   —->      Macrolides (Erythromycin, Azithromycin, Clarithromycin)

Alternative            —->        Cotrimoxazole


Q. 10

Disease highly transmitted during incubation period is –

 A

Pertussis

 B

Cholera

 C

Measles

 D

a and c

Q. 10

Disease highly transmitted during incubation period is –

 A

Pertussis

 B

Cholera

 C

Measles

 D

a and c

Ans. D

Explanation:

Ans. is ‘a’ i.e., Pertussis; ‘c’ i.e., Measles
“As a rule, infectious diseases are not communicable during the incubation period, but there are exceptions, for example, measles, chickenpox, whooping cough (pertusis) and hepatitis A are communicable during the later part of incubation period”.


Q. 11

What is false about pertussis –

 A

Maternal antibody provides protection in infants

 B

Fomites play a small role in spread of disease

 C

Commonly seen in infants

 D

b and c

Q. 11

What is false about pertussis –

 A

Maternal antibody provides protection in infants

 B

Fomites play a small role in spread of disease

 C

Commonly seen in infants

 D

b and c

Ans. A

Explanation:

Ans. is ‘a’ i.e., Maternal antibody provides protection in infants 

o Infants are susceptible to infection from birth because maternal antibody does not give them protection.

o Mode of transmission —> Whooping cough is spread mainly by droplet infection and direct contact. Each time the patient coughs, sneezes or talks, the bacilli are sprayed into the air. Most children contract infection from their playmates who are in the early stages of the disease. The role of fomites in the spread of infection appears to be very small, unless they are freshly contaminated.


Q. 12

Most common source of infection for whooping cough-

 A Chronic carrier

 B

Acute carrier

 C

Case

 D

Convelescent carrier

Q. 12

Most common source of infection for whooping cough-

 A

Chronic carrier

 B

Acute carrier

 C

Case

 D

Convelescent carrier

Ans. C

Explanation:

Ans. is ‘c’ i.e., Case 
o B. Pertussis infects only man.

o The source of infection is a case of pertussis.


Q. 13

The usual incubation period of pertusis is ‑

 A 7-14 days

 B

3-5 days 

 C

21-25 days

 D

Less than 3 days

Q. 13

The usual incubation period of pertusis is ‑

 A

7-14 days

 B

3-5 days 

 C

21-25 days

 D

Less than 3 days

Ans. A

Explanation:

Ans. is ‘a’ i.e., 7-14 days 

After an incubation period of about 1-2 weeks, the disease takes a protracted course comprising three stages, – the catarrhal, paroxysmal and Convalescent – each lasting approximately two weeks.


Q. 14 True about Pertussis is/are –

 A

Incubation period is 7-14 days

 B

Main source of infection is chronic carriers

 C

Can affect any age

 D

a and c

Q. 14

True about Pertussis is/are –

 A

Incubation period is 7-14 days

 B

Main source of infection is chronic carriers

 C

Can affect any age

 D

a and c

Ans. D

Explanation:

Ans. is ‘a’ i.e., Incubation period is 7-14 days, ‘c’ i.e., Can affect any age 

o Incubation period of Pertussis is 7-14 days.

o Source of infection is only a case of pertussis.

o Pertussis is primarily a disease of infants and preschool children. However it can also affect, though less commonly, older children, adolescents and adults.

o SAR in unimmunized household contacts is 90%.

o More cases occur during winter and spring month, due to overcrowding.


Q. 15

True regarding pertusis is all, except –

 A

Infectivity is highest in paroxysmal state

 B

Cross immunity is not seen with B. parapertusis

 C

Chronic carrier state is not seen

 D

Secondary attack rate is 90%

Q. 15

True regarding pertusis is all, except –

 A

Infectivity is highest in paroxysmal state

 B

Cross immunity is not seen with B. parapertusis

 C

Chronic carrier state is not seen

 D

Secondary attack rate is 90%

Ans. A

Explanation:

Ans. is ‘a’ i.e., Infectivity is highest in paroxysmal state 

o Infectivity is maximum in catarrhal stage (not in paroxysmal stage).

Option b require some explanation here :‑

o Most of the cases of whooping cough is caused by B. pertussis.

o In a small percentage of cases (< 5%), it is caused by B. parapertussis.

o There is no cross immunity of B. pertussis with B. parapertussis —> antibodies against B. Pertussis do not protect against B. parapertussis.


Q. 16 In control of pertussis, the drug of choice for cases‑

 A

Erythromycin

 B

Ciprofloxacin

 C

Tetracycline

 D

Penicillin

Q. 16

In control of pertussis, the drug of choice for cases‑

 A

Erythromycin

 B

Ciprofloxacin

 C

Tetracycline

 D

Penicillin

Ans. A

Explanation:

Ans. is ‘a’ i.e., Erythromycin 

Control of whooping cough

o Control of whooping cough requires :‑

1)       Management of cases and contacts

2)       Prevention by active immunization

Cases: Erythromycin is the DOC. Alternatives are ampicillin, tetracyclin & septran.

Contacts : Those who are exposed —> 10 days erythromycin


Q. 17 Which of the following statements is true regarding pertussis ?

 A

Neurological complication rate of DPT is I in 50000

 B

Vaccine efficacy is more than 95%

 C

Erythromycin prevents spread of disease between children

 D

The degree of polymorphonuclear Leukocytosis correlates with the severity of cough

Q. 17

Which of the following statements is true regarding pertussis ?

 A

Neurological complication rate of DPT is I in 50000

 B

Vaccine efficacy is more than 95%

 C

Erythromycin prevents spread of disease between children

 D

The degree of polymorphonuclear Leukocytosis correlates with the severity of cough

Ans. C

Explanation:

Ans. is ‘c’ i.e., Erythromycin prevents spread of disease between children

o Efficacy of Pertusis Vaccine – reported to be from 70-90%

o Risk of acute encephalopathy – is 1 in 40, 000 cases following DTP vaccine.

o Pertusis toxin produces Lymphocytosis & not polymorphonuclear Leukoctyosis.

Leukocytosis due to absolute lymphocytosis is characteristic in late catarrhal or paraoxysmal stage.

o Prophylactic erythromycin prevents infecting bacteria to become established – prevents spread of disease – Park


Q. 18 Which of the following was a part of expanded programme of immunization ‑

 A

Hepatitis B

 B

Rubella

 C

Pertussis

 D

Mumps

Q. 18

Which of the following was a part of expanded programme of immunization ‑

 A

Hepatitis B

 B

Rubella

 C

Pertussis

 D

Mumps

Ans. C

Explanation:

Ans. is ‘c’ i.e., Pertussis
In may 1974, the WHO officially launched a global immunization programme, known as expanded programme of immunization (EPI) to protect all children of the word against six vaccine-preventable diseases by the year 2000.


Q. 19

A 16-year-old male presents with a nagging, worsening cough that has been present for 4 weeks. His blood smear is shown here. What is the diagnosis? 

 A

Bordetella pertussis.

 B

Streptococcus pharyngitis.

 C

Mycoplasma pneumoniae.

 D

Respiratory syncytial virus.
 

Q. 19

A 16-year-old male presents with a nagging, worsening cough that has been present for 4 weeks. His blood smear is shown here. What is the diagnosis? 

 A

Bordetella pertussis.

 B

Streptococcus pharyngitis.

 C

Mycoplasma pneumoniae.

 D

Respiratory syncytial virus.
 

Ans. A

Explanation:

The answer is A, Bordetella pertussis infection. Bordetella pertussis infection is one of only two infectious diseases (the other is infectious lymphocytosis) that manifests in the blood as a mature lymphocytosis. A “mature” lymphocytosis is one in which the cells appear relatively small, with condensed chromatin, and no unusual “reactive” changes – basically, they look like regular old mature lymphocytes.
In Bordetella, the lymphocytes often have a weird “clefted” appearance” as shown in the photomicrograph below. 


Q. 20

Pertussis vaccine side effect

 A

Local pain

 B

Excessive cry

 C

Fever

 D

All of above

Q. 20

Pertussis vaccine side effect

 A

Local pain

 B

Excessive cry

 C

Fever

 D

All of above

Ans. D

Explanation:

Ans. is ‘d’ i.e., All of the above
Pertussis vaccine

  • Available as whole cell and acellular as DTPw and DTPa
  • Primary immunisation at 6, 10, 14 weeks followed by booster dose 1’/2 year and 5 year.
  • Whole cell causes more side effect than acellular
  • Side effect-local pain, redness, fever, irritability, excessive cry because of cortical irritation.

Contraindication

  1. Progressive neurological disease (Relative)
  2. Immediate anaphylasix
  3. Encephalopathy
  4. Persistent Inconsable cry
  5. Hypotensive – hyporesponsive episode

Q. 21 Threshold level of herd immunity for Pertussis is‑

 A

80%

 B

70%

 C

90%

 D

50%

Q. 21

Threshold level of herd immunity for Pertussis is‑

 A

80%

 B

70%

 C

90%

 D

50%

Ans. C

Explanation:

Ans. is ‘c’ i.e., 90% 
Herd immunity

  • It is the level of resistance of a community or group of people to a particular disease.
  • It occurs when the vaccination of a portion of the population (or herd) provides protection to unprotected (non‑ vaccinated) individuals.
  • Advantage of herd immunity
  • It is not necessary to achieve 100% immunization to control a disease by providing herd immunity.
  • When a certain percentage of population, is vaccinated, the spread of disease is effectively stopped.
  • This critical percentage is referred to as herd immunity threshold.

Disease                Herd immunity threshod

Diphtheria      →      85%

Measles          →      83-94%

Mumps           →      75-86%

Pertussis        →      92-94%

Polio              →      80-86%

Rubella          →      80-85%

Small pox      →      83-85%


Q. 22 Secondary attack rate of pertussis in unimmunization household contacts of pertussis

 A

30%

 B

40%

 C

60%

 D

90%

Q. 22

Secondary attack rate of pertussis in unimmunization household contacts of pertussis

 A

30%

 B

40%

 C

60%

 D

90%

Ans. D

Explanation:

Ans. is ‘d’ i.e., 90%

SAR of some important infectious diseases

Measles
Rubella
Chicken pox
Pertussis
Mumps

80%

90 – 95%

— 90%

— 90%

86%



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