Control Guideline for Public Health Units

Contact management: For cases under 5 years of age or cases of any age who are NAT or culture confirmed, or cases reported to have close contacts who may be at high risk for pertussis, counsel contacts at risk of disease and facilitate preventive therapy.

Last updated: 23 January 2015
Download
  1. Summary
  2. The disease
  3. Routine prevention activities
  4. Surveillance objective
  5. Data management
  6. Communications
  7. Case definition
  8. Laboratory testing
  9. Case management
  10. Control of environment
  11. Contact management
  12. Special situations
  13. References
  14. Appendices

1. Summary

Case and contact management is challenging for pertussis. The evidence base is limited and the epidemiological behaviour of Bordetella pertussis is not well understood. This partly explains why pertussis is a poorly controlled bacterial vaccine-preventable disease.

Public health priority

High

Begin public health follow up as soon as possible, generally within 1 working day (see Response Times in Section 9). The objective of public health follow up of pertussis cases is to prevent disease in infants <6 months of age with particular focus on exposures in household, child care and health care settings. Therefore highest priority should generally be given to cases who are nucleic acid test (NAT) or culture confirmed and:

  • If the case is a child under 5 years of age, follow up the younger cases (<2 years) before the older cases
  • Other age groups where cases are already known to have close contacts that include infants <6 months of age
  • Are women known to be in the last month of pregnancy

No action is required for cases notified >21 days after the onset of paroxysmal cough (if the onset is known) or >28 days after the onset of any cough unless they are reported to be part of a cluster.

Case management

It is the responsibility of the treating doctor to treat infectious cases and consider the need for further public health action for any high risk contacts. For cases considered high public health priority (see above) contact the treating doctor or case to identify any contacts that are infants <6 months of age or people who may transmit pertussis to these infants, and advise on management of case and contacts as necessary. For other cases, an advisory letter may be sent to the treating doctor, as required.

Contact management

For cases considered high public health priority, counsel their close contacts and facilitate antibiotic prophylaxis where necessary. Recommend that contacts’ immunisations be updated if appropriate.

2. The disease

Infectious agents

The bacillus Bordetella pertussis (B. pertussis)

Reservoir

Humans are the only reservoir for B. pertussis. Adults and adolescents are often an important source of infection for infants. [1]

Mode of transmission

Pertussis is mainly transmitted by large droplet infection or direct contact with discharges from respiratory mucous membranes of infectious people. Indirect spread via contaminated objects occurs rarely.[2] There is some experimental evidence which supports airborne transmission over distances greater than one metre.[3]

Clinical presentation and outcome

Pertussis is a prolonged coughing illness with clinical manifestations that vary by age. An initial catarrhal phase is characterised by the insidious onset of runny nose, sneezing, absent or low- grade fever, and a mild occasional cough. The cough gradually becomes paroxysmal (after 1–2 weeks), and may end in vomiting, cyanosis and/or a characteristic high-pitched inspiratory ‘whoop’. Paroxysms may recur with subsequent respiratory illnesses for many months after the onset of pertussis. [1] Fever is generally minimal throughout the course of the illness and sub- clinical infections may occur. [1] Infants are less likely to have the inspiratory whoop and a significant catarrhal stage and are more likely to present with gagging, gasping, cyanosis, apnoea or non-specific signs such as poor feeding or seizures. [4]

Adults and children partially protected by vaccination can present with illness ranging from a mild cough illness to classic pertussis, though this may be without the inspiratory whoop. In adults, post-tussive vomiting (when present) is strongly suggestive of pertussis. [4] The most common complication is pneumonia caused either by B. pertussis infection itself, or co-infection with viral respiratory pathogens such as respiratory syncytial virus (RSV). [4] Encephalopathy is a rare complication. [4]

Incubation period

The incubation period ranges from 4-21 days, usually 7 to 10 days. [1]

Infectious period

Cases are infectious from the onset of catarrhal symptoms. Communicability gradually decreases and is negligible 3 weeks after onset of cough. Secondary attack rates of 80% among susceptible household contacts have been reported. [1] For public health purposes, a case is considered non-infectious (even if the PCR result is still positive) at whichever time is the earlier of:

  • 21 days after the onset of any cough, or
  • 14 days after onset of paroxysmal cough (if the onset is known), or
  • when they have completed 5 days of a course of an appropriate antibiotic.

Persons at increased risk of disease

Infants under 6 months of age account for the vast majority of pertussis hospitalisations and deaths; Australian data for 2009-2010 indicate a case fatality rate of less than 0.5% in infants too young to be protected by vaccine. [5, 6]

Disease occurrence and public health significance

Globally, pertussis remains a major health problem despite widespread vaccination programs. In 2009, 195 000 deaths were estimated from the disease, mostly in developing countries. [7] In Australia, pertussis is the most common acute vaccine preventable disease with epidemics occurring approximately every 3-4 years and the timing of epidemic activity varying across jurisdictions. [8] It has only relatively recently been widely recognised as a common disease of older children and adults.

3. Routine prevention activities

Apart from direct case and contact management of pertussis, the following activities are routine prevention activities at the population level.

Vaccination

Pertussis immunisation is recommended for all Australian children with the first dose of pertussis-containing vaccine given from 6 to 8 weeks of age [9], followed by doses at 4 and 6 months, a booster from 3.5-4 years of age [10] and a further booster at 12-17 years of age. Lower-dose dTpa vaccines suitable for use in adolescents and adults have been available since 2001. Since 2003, dTpa vaccine has been recommended for healthcare workers and people working or living with infants, including parents, grandparents, those planning pregnancy and childcare workers who have not previously had a dose of the acellular vaccine. Immunity following vaccination begins to wane after as little as 4-5 years. [11]

Increase awareness

Amongst the general public, it is important to raise awareness of:

  • early diagnosis and treatment of cases, by encouraging people with coughing illnesses to seek early medical attention. This will facilitate timely treatment of pertussis cases (to reduce infectiousness) and follow up of high risk contacts.
  • respiratory hygiene around babies, by encouraging people with coughing illnesses to avoid contact with infants <6 months of age until a diagnosis is made and they are no longer infectious.

Amongst general practitioners and other clinicians, it is important to promote ongoing clinical education about pertussis that outlines appropriate diagnosis, treatment and the identification and management of contacts.

4. Surveillance objective

The objective of surveillance for pertussis is to monitor and analyse the epidemiology of the disease, including the impact of immunisation, and to report on findings to inform effective and efficient prevention strategies.

The objective of public health follow up of pertussis cases is to prevent disease in infants <6 months of age with particular focus on exposure in household, childcare and healthcare settings

5. Data manage​ment

Within 3 working days of notification, enter confirmed and probable cases onto the jurisdictional notifiable diseases database. As soon as practicable, check and enter vaccination details for cases under 5 years of age.

6. Communications

  • Within 1 working day of becoming aware of a death from pertussis, notify the state/territory Communicable Diseases Branch of the case’s age, sex, date of onset, vaccination history, laboratory status, likely source of infection and follow up action taken.
  • The state/territory Communicable Diseases Branch should notify the case details to the CDNA secretariat and update the ‘died’ field in the national notifiable diseases database.
  • The state/territory Communicable Diseases Branch should also be notified of significant pertussis exposures in healthcare settings.

7. Case definit​ion

Confirmed case

A confirmed case requires either:

  • Laboratory definitive evidence, or
  • Laboratory suggestive evidence and clinical evidence

Probable case

A probable case requires clinical evidence and epidemiological evidence

Laboratory definitive evidence

  • Isolation of Bordetella pertussis, or
  • detection of B. pertussis by nucleic acid testing, or
  • seroconversion in paired sera for B.pertussis using whole cell or specific B.pertussis antigen(s) in the absence of recent pertussis vaccination.

Laboratory suggestive evidence

In the absence of recent vaccination

  • Significant change (increase or decrease) in antibody level (IgG, IgA) to B.pertussis whole cell or B.pertussis specific antigen(s), or
  • single high IgG and/or IgA titre to Pertussis Toxin (PT), or
  • single high IgA to Whole Cell B. pertussis antigen.

Clinical evidence

  • A coughing illness lasting two or more weeks, or
  • paroxysms of coughing or inspiratory whoop or post-tussive vomiting.

Epidemiological evidence

An epidemiological link is established when there is:

  • contact between two people involving a plausible mode of transmission at a time when:
    • one of them is likely to be infectious (from the catarrhal stage, approximately one week before, to three weeks after onset of cough) and
    • ​the other has an illness which starts within 6 to 20 days after this contact and
  • at least one case in the chain of epidemiologically linked cases (which may involve many cases) is a confirmed case with at least laboratory suggestive evidence.

8. Laboratory testing

Testing guidelines

Routine testing of patients is at the discretion of the treating doctor. Public health personnel should encourage testing to confirm any probable cases where contacts <6 months of age have been reported. Laboratory testing of asymptomatic contacts should be discouraged.

With increasing availability, nucleic acid testing (NAT) should be considered the diagnostic method of choice, unless the presentation is delayed until after 4 weeks from any cough onset, or more than 3 weeks after commencement of paroxysmal cough, after which time serological testing may be more useful for diagnosis.

Nucleic acid testing (NAT)

  • Nucleic acid testing (NAT) (also known by the proprietary name of PCR) has largely replaced culture for the diagnosis of pertussis. NAT is more sensitive than culture and has optimal sensitivity during the first 3 weeks of cough. After the fourth week of cough, sensitivity declines as the amount of bacterial DNA in the nasopharynx diminishes. [12]
  • NAT can be positive for 5 weeks or longer; refer to Section 2 for guidance on the infectious period for public health purposes.
  • NAT testing after 5 days of appropriate antibiotics is unlikely to be of benefit and is generally not recommended. [12]
  • Nasopharyngeal aspirates or nasopharyngeal swabs with Dacron™ or rayon tipped swabs are optimal and calcium alginate swabs should not be used. Throat swabs may also be used, although they suffer from lower sensitivity. Swabs for NAT should be sent to the laboratory dry – not in transport medium.
  • Further information including technique for collection of nasopharyngeal swab or aspirate is available from the Centre for Disease Control

Culture

  • The sensitivity of nasopharyngeal culture decreases rapidly after cough onset and is highly dependent on specimen quality. Cultures are rarely positive after 2 weeks from the onset of the catarrhal stage of the illness, or one week of paroxysmal cough, or for more than a few days after starting antibiotics.
  • If it is proposed to collect samples for culture of B. pertussis, the laboratory should be contacted beforehand to enable swabs and culture media to be processed promptly.
  • Nasopharyngeal (not throat) cultures should be collected either by aspiration or with a flexible, deep nasal swab. The swab should be inoculated directly onto special pertussis culture medium or into transport medium, or both, according to the laboratory's specific instructions. The technique is illustrated by the Centre for Disease Control
  • Cultures may take as long as 2 weeks to be finalised, so results may not be clinically useful.

Serology

  • Although serological testing of pertussis has not been standardised, it was the predominant diagnostic test until recently. Bordetella-specific IgA directed against whole-cell lysate has been the most widely used test, particularly in adults and adolescents who present late in the course of their illness, when both culture and NAT are likely to be negative. The serological assays in use are, however, changing, with increasing use of purified antigens such as pertussis toxin (PT) alone or in combination with filamentous haemagglutinin (FHA). International standards for anti-PT and anti- FHA IgG and IgA have become available and should allow for greater standardisation of assays in the future.
  • The sensitivity and specificity of serology is low. Serology may be useful if a clinically compatible illness has been present for more than two weeks, but is not recommended in children <2 years old as they are less likely to develop IgA antibodies and because phlebotomy can be difficult for inexperienced venepuncturists.
  • Depending on which antigens are used in the assay, a positive Bordetella serological result may also occur in parapertussis.
  • IgA and IgG may be elevated for an unknown period (reported as 1 year [13] but may be as long as 2 years) in an adult or adolescent after vaccination, therefore caution should be taken in interpreting serological results in a recently vaccinated person.
  • Bordetella-specific IgG and IgA rise during acute infection. If only a convalescent sample is available the current suggestive criteria for recent infection in the absence of recent vaccination include an elevated IgA antibody level to whole-cell B. pertussis or an elevated IgG and/or IgA to pertussis toxin or other combination antigens. Commercial and in-house validated assays utilising PT with or without FHA are now being introduced.
  • Bordetella IgM serology is available using commercial kits, but is currently not considered sufficiently sensitive and specific for guiding public health decisions. An IgM response may follow infection in young children in whom the IgA response is not yet mature.

For further information on laboratory testing refer to the Public Health Laboratory Network (PHLN) laboratory case definitions.

9. Case management

Response times

Begin the follow up within 1 working day of notification of high priority cases who are NAT/culture confirmed, and more likely to be in contact with infants <6 months of age. The principles for prioritising the workload among NAT/culture confirmed high priority cases are:

  • If the case is a child <5 years, follow up the younger cases (<2 years) before the older cases
  • Follow up any case in a woman known to be in the last month of pregnancy
  • Follow up where the case is already known to be in contact with infants <6 months of age or women in the last month of pregnancy
  • Follow up where the case is known to attend or work in a setting where there is likely to be contact with infants <6 months of age or women in the last month of pregnancy (e.g. certain childcare and healthcare settings)

Active public health action (e.g. exclusion, antibiotic use) is not required for cases notified >21 days after date of onset of paroxysmal cough (if the onset is known) or >28 days after the onset of any cough - unless they are reported to be part of a cluster - as they are unlikely to be infectious.

Response procedure

Case investigation

For cases given priority as outlined above, response will usually be carried out in collaboration with the treating doctor. Public health personnel should:

  • Provide advice on case and contact management. The Public Health Unit may send a letter and factsheet (see Appendices) to the treating doctor recommending case and contact management
  • Investigate the case using a pertussis case investigation form (see Appendices)
  • For cases under 5 years of age, check and record primary vaccination status (including source of verification)

For any other cases meeting the current case definition public health personnel may offer, as resources permit, to assist the treating doctor with cases when either high risk contacts or clusters are identified by the treating doctor.

Exposure Investigation

Where feasible for cases given priority, investigate the possible source of exposure-contact with a confirmed or suspected case/s.

Case treatment

Antibiotics given early in the catarrhal stage may ameliorate the disease but may have little effect on symptoms if given later. [14] Importantly, antibiotics reduce the period of communicability [15] and should be initiated as soon as possible. If treatment starts any later than 14 days from onset of any cough, by the time 5 days of treatment are completed, the case is already close to the end of their infectious period (21 days). Treatment is the responsibility of the attending doctor. However, it should be noted that azithromycin, especially the syrup form, may be difficult and/or expensive to obtain and that specific advice may be required. For recommended treatment see the latest edition of Therapeutic Guidelines: Antibiotic. [16] In 2014 the recommendations were updated and are outlined in Table 1:

Table 1. Recommended antibiotic treatment and post exposure prophylaxis for pertussis by age group

​Age Group ​Macrolide:
Azithromycin​ (oral)
Macrolide:
Clarithromycin​ (oral)
Non-Macrolide alternative​:
Trimeth​oprim + Sulfamethoxazole​ (oral)
​<1 month ​10mg/kg daily for 5 ​days​ ​7.5mg/kg twice a day for 7 days (up to 500mg)​ ​Not recommended ​
​1-5 months ​10mg/kg daily for 5 days​ ​7.5mg/kg twice a day for 7 days (up to 500mg)​ ​Child ≥2 months 4+20mg/kg (up to 160+800mg) twice a day for 7 days
​Infants ≥6 months; and children ​10mg/kg (up to 500mg) on Day 1, followed by 5mg/kg (up to 250mg) on Days 2-5​ ​7.5mg/kg twice a day for 7 days (up to 500mg)​ ​4+20mg/kg (up to 160+800mg) twice a day for 7 days
​Adults ​500mg on Day 1 followed by 250mg on Days 2-5​ ​500mg twice a day for 7 days ​160+800mg twice a day for 7 days
​Pregn​ancy​ ​Pregnant women with onset of pertussis or exposure within a month of expected delivery should receive antibiotic therapy. It is the responsibility of the treating doctor to select the most appropriate antibiotic. Azithromycin is Category B1 and clarithromycin is a Category B3 antibiotic. [16​​​]


Therapeutic Guidelines: Antibiotic
notes there is currently no clinical evidence to recommend the use of roxithromycin for the management of pertussis. In vitro evidence indicates it is relatively ineffective. [17]

Education

The case or relevant care-giver should be advised about the nature of the infection and the mode of transmission. The factsheet is useful for this purpose (see Appendices). Cases should be advised to avoid contact with infants and women in the last month of pregnancy.

Isolation and restriction

Exclusion from work, school, preschool, and child care, and restricted attendance from other settings, especially where there are infants, should be recommended for cases until they are no longer infectious until:

  • ​21 days after the onset of any cough, or
  • 14 days after the onset of paroxysmal cough (if the onset is known) , or
  • They have completed 5 days of a course of an appropriate antibiotic.

In hospital settings, infectious cases should be managed with droplet precautions and accommodated in a single room. [18]

Active case finding

None routinely required, except in special situations (see Section 12 Case in a healthcare worker in a maternity ward or newborn nursery).

​10. Control of environment

Not required.

11. Contact management

Identification of contacts

The aim of identifying contacts is to:

  • Alert them to the possibility that they could develop disease, and
  • Recommend antibiotic prophylaxis for the subset who are infants <6 months of age or people who may transmit pertussis to these infants.

Direct contact with respiratory droplets from the case is likely to pose a significant risk of transmitting infection. [14]

Contact definition

In general terms, close contacts are people with face-to-face exposure (within 1 metre) to an infectious case, [14] for a single period of at least one hour (based on expert opinion). In the absence of evidence concerning the minimum duration of exposure required to lead to infections in neonates, a neonate exposed to an infectious case for less than one hour may warrant being considered a close contact. In addition, close contacts are usually considered to include family and household members and, in other settings, people who have stayed overnight in the same room as the case.* All close contacts or their carers should receive information about pertussis symptoms (e.g. factsheet).

In addition, a subset of close contacts are considered high-risk contacts because of the severity of disease or the likelihood of transmitting infection to those at risk of severe disease and are recommended antibiotic prophylaxis. For the purposes of this guideline, high-risk contacts are infants <6 months of age and people who may transmit pertussis to them.

In the event of exposure in the household setting, high-risk contacts include:

  • expectant parents (or carers) in the last month of pregnancy
  • all household members where there is an infant <6 months present.

In any setting, close contacts of a case who are considered high-risk contacts include:

  • healthcare staff working in a maternity ward or newborn nursery (where women in the last month of pregnancy or infants <6 months are present)
  • childcare staff who look after infants aged <6 months
  • children who have close contact in child care with children <6 months of age
  • women in the last month of pregnancy.

Management of immunodeficient contacts should be made on a case by case basis.

*In non-household settings, the size of the room and degree of separation of the case from others should be considered when close contacts are being identified.

Prophylaxis

Passive immunisation

Normal human immunoglobulin (NHIG) is not effective against pertussis. There is efficient transfer of protective maternal antibodies across the placenta with a half life of 6 weeks and disappearance by 4 months. [19] As pertussis antibodies wane over several years, there will be little humoral antibody protection for the infant unless the mother has been vaccinated or infected shortly before or during pregnancy. [19]

Active immunisation

Not applicable in the management of defined contacts. However immunisation should be promoted according to NHMRC recommendations.

Antibiotic prophylaxis

There is little evidence that antibiotic prophylaxis reduces secondary transmission outside of the household setting. [15, 20] The recommended antibiotics may have associated side effects (especially gastrointestinal) that reduce compliance. Therefore antibiotic prophylaxis should be limited to contacts that include infants <6months of age or people who may transmit pertussis to these infants (high-risk contacts). Antibiotic prophylaxis is only useful if given as soon as possible after first contact with an infectious index case [4, 14]. Based on the preceding statements and considering the decline in infectiousness during the infectious period, the timeline for providing antibiotic prophylaxis to high-risk contacts should be within 14 days of first contact with an infectious case and prophylaxis is recommended in the settings outlined in Table 2. Regimens for antibiotic prophylaxis are the same as for treatment of cases–See Table 1 under Section 9. Case management.

Due to lack of evidence of effectiveness from these settings, antibiotic prophylaxis is not considered valuable in other settings such as primary schools, high schools, tertiary institutions and work places. If there are prolonged or multiple chains of transmission, the benefit of antibiotic prophylaxis is likely to be minimal. [21] Circumstances in which further contact occurs with an index case satisfying the recommendations for antibiotic prophylaxis, should be assessed to determine the risk of severe disease in contact/s and the benefit of repeat antibiotic prophylaxis.

Use of Table 2: The table does not cover all possible scenarios; other settings or exposures of shorter duration where high-risk individuals have been exposed may warrant consideration for prophylaxis.

Presumptions and notes:

  • Transmission is by respiratory droplets requiring close ‘household-type’ contact [1]
  • Transmission is usually considered to require exposure within 1 metre for a single period of 1 hour. There is no evidence to guide decisions in relation to repeated shorter exposures over a period of time with a cumulative total greater than one hour.
  • While antibodies to pertussis begin to wane within a year after vaccination in adults, they remain above pre-vaccination levels for 10 years. [12] The 10th edition of The Australian Immunisation Handbook recommends that no further doses of dTpa vaccine be given routinely until 10 years after the first dose.[6]

Table 2. Recommendations for the management of contacts in various settings

Household Setting

Setting Provide Advice​ [A, B] Antibiotics [C] Exclusion [D] of non or incompletely vaccinated [E] people
​​Where household contacts include an incompletely vaccinated child <6 mon​ths or w​oman in the last month of pregnancy ​Household All household members, regardless of vaccination status [F] ​Not applicable
​All other households ​Household ​Nil ​Not applicable


Child care [G] setting (sporadic case)

Setting Provide Advice​ [A, B] ​Antibiotics [C] Exclusion [D] of non or incompletely vaccinated [E] people
​Where there is an incompletely vaccinated child <6 month​s in room (who is not the case) ​All staff and parents

​All children in room with <3 doses of vaccine.

Staff who have not had a pertussis-containing vaccine in last 10 years [H]

​Children: exclude for 5 days while on antibiotics or 14 days (from first exposure to infectious case) if they do not take antibiotics

Staff: not excluded while taking 5 days of antibiotics or recommend exclusion for 14 days (from first exposure to infectious case) if they do not take antibiotics

​Where all children are ≥6 months ​All staff and parents ​Nil

​Children: not excluded if they remain well

Staff: not excluded if they remain well

Child care setting with 2 or more cases in the same room within a single incubation period [I]

Setting​​​ Provide Advice​ [A, B] ​Antibiotics [C] Exclusion [D] of non or incompletely vaccinated [E] people
​ Where there is an incompletely vaccinated child < 6 months in room (who is not the case) ​All staff and parents

All children in the room regardless of vaccination status

All staff in the room regardless of vaccination status

​Children: exclude for 5 days while on antibiotics or 14 days (from first exposure to infectious case) if they do not take antibiotics

Staff: not excluded while taking 5 days of antibiotics or recommend exclusion for 14 days (from first exposure to infectious case) if they do not take antibiotics

​Where all children are ≥6 months ​All staff and parents

​All children in room with <3 doses of vaccine

Staff who have not had a pertussis containing vaccine in last 10 years [8]

Children: exclude for 5 days while on antibiotics or 14 days (from first exposure to infectious case) if they do not take antibiotics

Staff: not excluded while taking 5 days of antibiotics or recommend exclusion for 14 days (from first exposure to infectious case) if they do not take antibiotics

Healthcare settings where infants <6 months or women in their last month of pregnancy are present (including neonatal unit, maternity ward) [J]

S​etting​​ Provide Advice​ [A, B] ​Antibiotics [C] Exclusion [D] of non or incompletely vaccinated [E] people
​Case is staff member of unit / ward or an infectious patient who has not been appropriately isolated ​All staff and parents

​Infants <6 months exposed to the case within 1 metre for >1 hour [K]

Parents or carers of infants <6 months/women in last month of pregnancy [6] exposed to the case within 1 metre for >1 hour

All staff exposed within 1 metre for >1 hour in the unit who–in the next 3 weeks–are to care for neonates or women in the last month of pregnancy regardless of vaccination status

​Not applicable to Infants <6 months exposed to the case within 1 metre for >1 hour [K] or parents or carers of infants <6 months/women in last month of pregnancy [6] exposed to the case within 1 metre for >1 hour

Staff need only be excluded (immediately) if they become symptomatic and are to be excluded whilst considered infectious. In situations in which asymptomatic staff contacts have been recommended and refused antibiotics (e.g. an outbreak) recommend exclusion or restrict from working with infants <6 months and women in the last month of pregnancy (for 14 days from first exposure to the infectious case)

  1. These contacts should be alerted to the possibility that they could develop disease and to seek early medical assessment if they develop symptoms consistent with pertussis.
  2. Recommend vaccination to contacts, health care workers, and those who work with children who are incompletely vaccinated as they are likely to benefit in the future if vaccinated.
  3. Antibiotic prophylaxis is recommended for these contacts of pertussis cases, and should be given within 14 days of first exposure to an infectious case. Regimens for antibiotic prophylaxis are the same as for treatment of cases. See Table 1 under Section 9. Case management.
  4. Any contacts that develop symptoms should, where possible, be excluded (immediately) from childcare, preschool, school, health care and workplace settings and seek early medical assessment.
  5. In the childcare setting, any child that has received <3 doses of vaccine is considered incompletely vaccinated
  6. Choice of an appropriate antibiotic for use in pregnancy is the responsibility of the treating doctor. See Table 1 under Section 9. Case management
  7. Childcare settings include long day care, family day care or settings where children aged 4 years or less are in care before they start their first year in a school setting (this can be called preschool or kindergarten in certain jurisdictions). See also Section 12. Special situations: Cases among children in child care.
  8. Staff are regarded as vaccinated if they have had a pertussis-containing vaccine in the last 10 years
  9. See Section 12. Special situations: Outbreaks. Due to the variety of childcare settings where two or more cases may be epidemiologically linked and the absence of strong evidence for the effectiveness of antibiotic prophylaxis in these settings, a case by case assessment will usually be required to determine the appropriate response.
  10. See also Section 12. Special situations: Case in a healthcare worker in a maternity ward or newborn nursery
  11. In the absence of evidence concerning the minimum duration of exposure required for a neonate to be infected, a neonate exposed to an infectious case for less than one hour may warrant being considered a close contact and receiving antibiotic prophylaxis.

Education

Public health personnel should manage the distribution of information to contacts (usually in the form of a letter and factsheet) through the treating doctor, or if required, directly or via the case or other intermediary (e.g., director of the childcare centre, school principals, hospital infection control staff, etc.). Contacts should be advised that they are infectious as soon as they develop catarrhal symptoms and should be excluded (immediately) from child care, preschool, school, healthcare and workplace settings and seek early medical assessment.

Isolation and restriction

For childcare and healthcare settings, refer to the Exclusion section of Table 2. The general principles are to recommend exclusion of unvaccinated or incompletely vaccinated contacts (as outlined in Table 2) until:

  • The expiry of 14 days from their first exposure to the infectious case, or
  • They have completed 5 days of a course of an appropriate antibiotic.

The period of exclusion for 14 days from first exposure considers the highly (but waning) infectious nature of pertussis and covers the usual length of an incubation period (7-10 days). The benefit of exclusion is to:

  • Protect the child contact who has not received 3 effective doses of vaccine and therefore is not protected against disease, and
  • Reduce the risk of transmission from the child contact to any other person in the setting who is at increased risk of severe and/or complicated disease.

If parents do not follow an exclusion request despite public health personnel attempting to convince them of the need to do so, then specific jurisdictional public health legislative provisions, where they exist, may need to be applied.

In hospital settings, patients with pertussis should be in respiratory isolation until they are no longer infectious (i.e. until they have received at least 5 days of a course of an appropriate antibiotic). Ensure staff follow droplet precautions [18] (including wearing a surgical mask) during close contact with cases.

12. Special situations

Cases among children in child care

In this document child care refers to long day care, family day care or settings where children aged 4 years or less are in care before they start their first year of school (this can be called preschool or kindergarten in certain jurisdictions).

In addition to usual case and contact investigation, it is important to emphasise to parents and directors of childcare facilities the need to establish each child’s immunisation status, the importance of all children complying with the immunisation schedule and the need to remain alert for symptoms in their child/ren. It is also important to recommend that the facility remain alert for respiratory illness for at least an incubation period (21 days) after last contact with the infectious case and ensure appropriate management of any further cases.

In the family day care setting where one or more infants <6 months of age are being cared for, a case in the carer or a member of the carer’s family may warrant temporary closure, as exclusion of the case is generally not practicable.

Cases among children in playgroup

Exposures in the playgroup setting need to be considered on a case by case basis. Considerations need to include:

  • The length of time spent outdoors (which is considered a lower risk exposure)
  • The length of exposure time
  • The age of the children involved.

Cases among children in kindergarten/preschool or school

If advice is sought from the Public Health Unit in these situations, it is important to emphasise to parents and principals/directors of these facilities the need to establish each child’s immunisation status, the importance of all children complying with the immunisation schedule and the need to remain alert for symptoms in their child/ren. It is also important to recommend that the facility remain alert for respiratory illness for at least one incubation period (21 days) after last contact with the infectious case, that the facility report cases of respiratory illness and ensure appropriate management of any further cases.

Case in a healthcare worker in a maternity ward or newborn nursery

For probable or confirmed cases, consult immediately with facility management and staff from infection control or staff health to institute a management plan appropriate to the facility. This should include procedures to:

  • Confirm the diagnosis through expert clinical review and laboratory testing(ideally by PCR). Concurrent investigation of alternative diagnoses (e.g. Mycoplasma pneumoniae, Chlamydophila pneumoniae, viral (such as adenovirus, metapneumovirus, parainfluenza, influenza A and B, rhinovirus, RSV), and non-infectious causes) will assist in interpretation of equivocal or indeterminate serological results or where there may be co-infection.
  • Carry out active surveillance for pertussis among exposed patients, staff, students, volunteers and visitors.
  • Staff members, students and volunteers detected through active surveillance with symptoms suggestive of pertussis should be immediately excluded and requested to undergo prompt medical evaluation.
  • Manage cases appropriately. See Section 9. Case management.
  • Define and identify contacts for prophylaxis and exclusion. Refer to list of high risk contacts (see contact definition in Section 11) and recommendations in Table 2.
  • Review staff health records to ensure that all have been protected in line with current immunisation recommendations.

Cases who are pregnant

Pertussis infection early in pregnancy may provide subsequent protective antibodies to a neonate. As the timing of delivery is not predictable, a pregnant woman with pertussis onset within a month of expected delivery and her household contacts should receive antibiotic therapy [22] as recommended in Table 1. If the baby is born before the mother or household contacts have completed 5 days of a course of appropriate antibiotic treatment, then the baby should receive antibiotic prophylaxis.

Outbreaks

When outbreaks of pertussis are identified, additional control measures should be considered. An outbreak is defined as two or more cases which share a plausible epidemiological link e.g. clustered in time and place (such as in the same room, ward or similar confined setting where transmission is suspected to have occurred in that setting). An outbreak case definition of a cough illness lasting >14 days may be used to count cases, if one case has been laboratory confirmed. Depending on the people affected and nature of the setting, control strategies may also include:

  • Active case finding
  • Epidemiological studies to determine risks for infection
  • Alerts to doctors in the community
  • Media alerts to the wider community
  • Cocooning vaccination initiative
  • Other measures as appropriate, including community-wide promotion of vaccination.

If an outbreak occurs in a healthcare facility, an outbreak management team should be convened, including a senior facility manager, Public Health Unit staff if appropriate, an infection control practitioner and appropriate clinical staff.

13. References

  1. Centers for Disease Control and Prevention. Epidemiology and Prevention of Vaccine-Preventable Diseases, The Pink Book. 12th edn: National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention; April 2011.
  2. Heymann DL, editor. Control of communicable diseases manual. 19th edn. Baltimore: United Book Press; 2008.
  3. Warfel JM, Beren J, Merkel TJ. Airborne transmission of Bordetella pertussis. J Infect Dis2012;206(6):902-906.
  4. Waters V, Halperin S. Bordetella pertussis. In: Mandell GL, Bennett JE, Dolin R, editors. Principles and practice of infectious diseases. 7th edn. Philadelphia: Churchill Livingstone; 2010.
  5. NNDSS Annual Report Writing Group, Sloan-Gardner T, Stirzaker S, Knuckey D, Pennington K, Knope K, et al. Australia's notifiable disease status, 2009: annual report of the National Notifiable Diseases Surveillance System. Commun Dis Intell 2011;35(2):61-131
  6. NNDSS Annual Report Writing Group. Australia's notifiable disease status, 2010: annual report of the National Notifiable Diseases Surveillance System. In: unpublished data.
  7. World Health Organization. Pertussis. 2010. Accessed on 16 Mar. Available from (no longer available, Jan 2015): http://www.who.int/immunization_monitoring/diseases/pertuss​is/en/
  8. National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases. Vaccine Preventable Diseases in Australia, 2005 to 2007. Commun Dis Intell2010;34(Suppl ):S1-S167.
  9. Australian Technical Advisory Group on Immunisation Australian Government Department of Health and Ageing. ATAGI Bulletin 41st Meeting: 15-16 October 2009. In. Canberra; 2009.
  10. Australian Technical Advisory Group on Immunisation Australian Government Department of Health and Ageing. ATAGI Bulletin 44th Meeting: 24-25 February 2011. In. Canberra; 2011.
  11. Wendelboe AM, Van Rie A, Salmaso S, Englund JA. Duration of immunity against pertussis after natural infection or vaccination. Pediatr Infect Dis J2005;24(5 Suppl):S58-S61.
  12. National Center for Immunization and Respiratory Diseases Division of Bacterial Diseases. Best Practices for Health Care Professionals on the use of Polymerase Chain Reaction (PCR) for Diagnosing Pertussis 2011. Accessed on 23 Jan 2015. Available from: http://www.cdc.gov/pertussis/clinical/diagnostic-testing/diagnosis-confirmation.html
  13. ​World Health Organization. Pertussis vaccines: WHO position paper. Wkly Epidemiol Rec2010;85(40):385-400.
  14. Centers for Disease Control and Prevention. Recommended Antimicrobial Agents for the Treatment and Post-exposure Prophylaxis of Pertussis. MMWR Recommendations and Reports2005;54(No. RR-14).
  15. Altunaiji S, Kukuruzovic R, Curtis N, Massie J. Antibiotics for whooping cough (pertussis). Cochrane Database Of Systematic Reviews(Online) 2007(3):CD004404.
  16. Antibiotic Expert Group. Therapeutic guidelines: antibiotic. Version 14. Melbourne: Therapeutic Guidelines Limited; 2010.
  17. Kucers A, Crowe SM, Grayson ML, Hoy JF. The use of antibiotics: A clinical view of antibacterial, antifungal, and antiviral drugs. 5th edn. Oxford: Butterworth-Heinemann; 1997.
  18. National Health and Medical Research Council. Australian Guidelines for the Prevention and Control of Infection in Healthcare. Canberra: Australian Government; 2010.
  19. Edwards KM, Decker MD. Pertussis vaccines. In: Plotkin S, Orenstein W, Offit P, editors. Vaccines. Fifth edn. China: Elsevier; 2008.
  20. Dodhia H, Miller E. Review of the evidence for the use of erythromycin in the management of persons exposed to pertussis. Epidemiol Infect 1998;120:143-149.
  21. Manikkavasagan G. and the Pertussis Guidelines Group. Health Protection Agency Guidelines for the public health management of pertussis. London; 2010.
  22. Centers for Disease Control and Prevention. Prevention of Pertussis, Tetanus, and Diphtheria among Pregnant and Postpartum women and their infants. MMWR Recommendations and Reports2008;57(No. RR-4).

14. Appendices

Appendix 1 - PHU Checklist [PDF]
Appendix 2 - Pertussis Investigation Form [PDF]
Appendix 3 - Pertussis Factsheet
Appendix 4 - Sample Letter to Parents of a Child in a Childcare Facility with Pertussis [DOCX]
Appendix 5 - Fax Back Form for Preventing Pertussis in High Risk Groups [DOCX]

​​​​​​​ ​​