Inyo-Mono Public Health Officer Dr. Rick Johnson said, "There is evidence of disease in Mammoth Lakes, Crowley Lake, and at multiple child care and school sites."

Whooping Cough (Pertussis) Update – Frequently Asked Questions

This is written in response to questions we have received in the last few days. It is not meant to be read from start to finish, but jump directly to any questions you may have. Please contact us with additional questions that we can attempt to answer to the best of our ability.

What is the current (and evolving) situation?
In Mammoth Lakes, an additional number of individuals have been tested for whooping cough, and the results are expected late Thursday or Friday. In the meantime, since they all have illnesses consistent with whooping cough, or were in close contact with someone who had a laboratory confirmed case, they have been treated, and asked to remain out of child care or school for 5 days from the beginning of treatment. So, we still have 9 confirmed cases, and at least that many more probable or suspect cases. There is evidence of disease in Mammoth Lakes, Crowley Lake, and at multiple child care and school sites.
Is this happening anywhere else?

Inyo County healthcare providers are testing some persons, but no results have come back positive at this time. The California Department of Public Health (CDPH) is not aware of any other outbreaks in the State of California. Outbreaks have been reported throughout Montana and Washington State, and also in Texas and Colorado.
How common is whooping cough?

Even with the success of vaccines, whooping cough is still too common in the US. Many cases are not diagnosed and so are not reported. Nationally, over the last 5 years, between 10,000 and 27,000 cases have been reported each year. Mono County reported 18 cases in 2010, and only 2 in 2011. For reasons we don’t completely understand, cases vary from year to year and tend to peak every 3-5 years.
How is whooping cough spread?

It is very contagious. Spread is through respiratory secretions called droplets, usually within 6 feet of an individual with illness. Persons are contagious for the first 2 weeks of illness, when they generally only have cold-like symptoms (runny nose and sneezing, with occasional cough). They then continue to be contagious for up to 3 weeks after the onset of severe cough. Once persons have received antibiotics, they are no longer contagious after 5 days. In contrast to influenza, spread via contact with fomites (door knobs, faucets, telephones, computer keyboards, etc.) is thought to occur rarely, if ever.

Who is at increased risk of complications, serious disease, or death?
Infants under 1 year of age
Unimmunized children
Immunocompromised persons
Persons who have chronic lung disease, or neuromuscular disease
Who should consult with or see their health care provider?
Anyone with a cough illness lasting more than 2 weeks, especially if there are spasms or “paroxysms of coughing”, a “whoop” on breathing in, or vomiting associated with the coughing
Anyone who has been in close contact with a laboratory confirmed case, or in close contact with someone who has had a cough illness as just described above.
Anyone who has or will have close contact with a person of high risk as described above.

What is “close contact”?
Close contacts are defined as persons with exposure to a pertussis case where contact with respiratory secretions is likely. The duration and intensity of exposure needed to cause infection is unclear. However, being a household member, attending or working in the same child care setting, receiving a cough or sneeze in the face, performing a medical exam of the mouth, nose, or throat, sitting at adjacent desks or the same table at school, or sharing a confined space with an infectious person for >1 hour are generally considered significant exposures.

Who should be considered for testing for whooping cough?
Persons with a cough illness lasting >2 weeks
Persons with an acute cough illness of any duration who are high risk
Persons with an acute cough illness of any duration who have close contact with persons who are high risk

Who should be treated for whooping cough?
Antibiotic therapy (usually once a day for 5 days) is recommended for all laboratory confirmed cases, and for close contacts of confirmed cases who develop a cough illness, especially if the close contacts are high risk.
What is the “cocoon” strategy?
Clearly the highest risk group of dying from whooping cough is infants under 1 year of age. Therefore, we hope to ensure a protective wall of safety around these infants. This wall would include:
Pregnant women in their third trimester
All household contacts, including dad, older siblings, family members (aunts, uncles, grandparents), babysitters, friends
All those working in a childcare setting
Healthcare workers who care for infants <1 year of age or pregnant/postpartum women

Who should be given a course of “prophylactic” or preventive antibiotics?
This is called post-exposure prophylaxis (PEP), e.g., giving antibiotics to those who have been exposed in order to prevent them from getting sick and in turn exposing others.  Both the Centers for Disease Control and Prevention (CDC), and the American Academy of Pediatrics (AAP), recommend PEP for all close contacts. However, it is recognized that antibiotic prophylaxis does not control the transmission of whooping cough when it is widespread in the community.

Utilizing the “cocoon” strategy, the focus is on preventing the spread of disease to those most likely to have severe disease or death. This is the approach recommended by the California Department of Public Health (CDPH), and the one that we are recommending. PEP, like treatment, usually also consists of an antibiotic once a day for 5 days.

For those close contacts not immediately getting PEP, they should be instructed to monitor themselves closely for cold-like symptoms for 21 days after last exposure and notify their health care provider or public health if symptoms occur so that antibiotic therapy (and 5 day exclusion) can be started immediately. Starting PEP >3 weeks after the last exposure to an infectious case is probably of no benefit to the contact.

What about being vaccinated?
All infants and children should receive the regularly scheduled doses of DTaP appropriate for their age. In the midst of an outbreak as we have, there is the option of an accelerated schedule. The first dose can be given at 6 weeks of age, with at least 4 weeks between each of the first 3 doses. Even one dose of DTaP may offer some protection against fatal whooping cough disease.

All adolescents and adults should receive one dose of Tdap vaccine if they have not done so already. This includes anyone older than 7 years of age, and recent recommendations include those >65. There is no minimum interval between the last dose of Td and the Tdap.

Why are we seeing whooping cough when most people have been vaccinated already?

The vaccine is far from perfect, and only protects about 50-80% of those who are fully vaccinated for age. Last year was the first year in 20 years that California had no deaths from pertussis, and we believe that this was due to the vigorous “cocoon” strategy of vaccinating all persons in close contact with infants <1 year of age. In spite of this success, both the DTaP vaccine (given to infants and children), and the Tdap vaccine (given to adolescents and adults) don’t provide the long lasting immunity that we would desire. In addition, questions have been raised about the ability of the pertussis bacteria itself to mutate into a new family which is not affected by the vaccine. Current vaccines are certainly safer than older ones used when I was a kid, but they are also not as good. There is always a tradeoff between effectiveness and safety.

What recommendations have you made to child care and school sites?
We have been working closely with health care providers, child care sites, schools, and parents, and have received excellent cooperation. Thank you!!
All health care providers, child care staff, school staff, parents, public, and media are being kept informed of the latest information, including signs/symptoms, prevention, and control measures.
We have been working together to identify all cases and close contacts.
All identified cases have started treatment.
All identified cases have been excluded from child care or school until completion of 5 days of effective antibiotic treatment.
All staff  in close contact with cases have started prophylaxis.
All high risk individuals who have had close contact with cases have been started on prophylaxis.
The vaccination status of all those in contact with high risk persons has, or is being determined, and any not up-to-date have or will be offered vaccine.
The vaccination status of all high risk persons has been documented, and any deficiencies corrected.
Enforcement of cough exclusion policies, and co-mingling policies, has been emphasized.
The possibility of facility closure has been considered, discussed with CDPH, and not considered appropriate at this point in time.

Who pays for all of this?
There is a tremendous amount of staff time being put in by affected facilities, including school, child care, clinics, and public health. All of that is absorbed into existing already stressed budgets, by staff who already have a full plate. Unfortunately, there are no additional funds available to assist parents and staff with medications, vaccinations, or the additional cost of time off when children are excluded from child care or school. We empathize with you, but we must remember that the life and safety of our youngest citizens demands a prudent, measured, reasonable, and rational response to this outbreak.
Where do you get your recommendations?
We utilize subject matter experts and advice from the CDPH and the CDC, adapted to our local evolving situation. We are grateful for their availability and support, especially during an outbreak in our relatively small jurisdiction.
Two useful Web sites for more information: