[2025 Travel Alert] Pertussis outbreak in Japan! Everything you need to know about it: symptoms, transmission, vaccines, and prevention
Lifestyle2025-06-09
6 Mins Read
Recently, Japan has experienced its most severe Pertussis outbreak in recent years. According to the data from the Japan Institute for Health Security, as of week 12 in 2025, there have been a total of 4,200 Pertussis cases nationwide, surpassing the entire total for 2024 and marking the highest number recorded for this period since 2018. Pertussis is mainly spread through respiratory droplets and is highly contagious, particularly affecting adolescents aged 10 to 19, who account for 60.3% of cases in 20251. This highlights schools and households as the primary locations of transmission.
For travellers planning to visit Japan, understanding Pertussis, ensuring vaccination, and purchasing appropriate travel insurance can not only reduce the risk of infection but also help ensure a smooth and safe trip.
What is Pertussis? Who is at high risk?
Pertussis (also known as 'Whooping Cough') is an acute bacterial respiratory infection caused by Bordetella pertussis. It is highly contagious. In the early stages, symptoms may be mild and resemble, only runny nose, sneezing, mild fever, and coughing. However, the cough gradually becomes more severe, often accompanied by a distinctive 'whooping' sound during inhalation. The condition can interfere with eating and breathing, and in serious cases, may lead to convulsions or loss of consciousness.
How is Pertussis transmitted?
- Through airborne droplets, such as those bacteria released when coughing or sneezing
- Highly infectious, with individuals able to transmit the bacteria even before coughing symptoms appear
- Incubation period: typically 7 to 10 days
High-risk groups for Pertussis
Group | Reason |
Infants and young children | |
Infants and young children | Their immune systems are not yet fully developed, making them more prone to complications such as pneumonia, seizures, or even death. |
Elderly (aged 65 and over) | |
Elderly (aged 65 and over) | Weakened immunity can make the illness harder to manage, with a higher risk of severe complications such as pneumonia and urinary incontinence, and a longer recovery period. |
Pregnant women | |
Pregnant women | The infection may be passed to the newborn via the placenta. |
School-aged children and teenagers | |
School-aged children and teenagers | Infections can spread rapidly in group settings such as schools. |
Why should adults also be cautious?
Although symptoms in adults are usually milder, they can still transmit the infection to others—particularly to infants who have not yet completed their vaccinations or to family members with weakened immune systems—potentially leading to household outbreaks.
Symptoms of Pertussis
Catarrhal stage (First week after incubation, similar to a common cold)
- Duration: Approximately 1 to 2 weeks
- Symptoms: Runny nose, sneezing, mild fever, dry cough (cough gradually worsens)
- Characteristics: This stage is the most contagious. It is often mistaken for a common cold and easily overlooked, which can delay isolation and treatment.
Paroxysmal cough stage (Weeks 2 to 6)
- Symptoms become severe and pronounced: Sudden, intense bouts of coughing (multiple coughs in a row), a 'whooping' sound during deep inhalation after coughing, vomiting (due to severe coughing), night-time coughing worsens, seriously affecting sleep, flushed or bluish face, sometimes temporary oxygen deprivation
- Special reminder: Infants may not produce the typical coughing sound but can experience breathing pauses or cyanosis (turning blue), requiring special attention.
Convalescent stage (Can last several weeks to months)
- Frequency and severity of coughing gradually decrease, but symptoms may relapse with reinfection
- In some cases, coughing symptoms may persist for 6 to 10 weeks or longer, which is why Pertussis is also known as the '100-day cough'.
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Treatment for Pertussis
Antibiotic treatment
- Common antibiotics: Azithromycin, Erythromycin, Clarithromycin
- Purpose: Helps reduce infectiousness, especially when administered early during the catarrhal stage. While antibiotics may not immediately relieve coughing in patients who have entered the paroxysmal cough stage, they can still prevent further transmission and help ease the condition
- Preventive treatment for household contacts: If there is an infant or high-risk individual in the home, doctors may recommend that other family members also take antibiotics to prevent the spread of infection
Supportive care (Symptom relief and recovery support)
- Rest and hydration: Getting adequate sleep and staying well-hydrated can help reduce the frequency and severity of paroxysmal cough
- Avoid irritants: Steer clear of second-hand smoke, dust, and cold air to minimise cough triggers
- Oxygen therapy / Hospital care: In severe cases—especially when infants experience breathing difficulties, cyanosis, or seizures—hospitalisation and close monitoring may be necessary
Is hospitalisation required for Pertussis?
Condition | Hospitalisation required |
Infants (especially under 6 months) | |
Infants (especially under 6 months) | ✅ Yes – Close monitoring of breathing and feeding is necessary |
Complications (e.g. pneumonia, seizures) | |
Complications (e.g. pneumonia, seizures) | ✅ Yes – Hospital treatment is essential |
Mild symptoms in adults/children | |
Mild symptoms in adults/children | ❌ No – Usually manageable at home with monitoring |
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Can Pertussis resolve on its own?
Some adults or teenagers with mild symptoms may gradually recover over the course of several weeks to months, even without antibiotics treatment. However, it’s important to be aware of the following:
- The coughing stage of Pertussis can last up to 100 days, significantly affecting daily life and work.
- During the untreated period, the infection is highly contagious and can easily be passed on to family members.
- In high-risk groups—such as infants, the elderly, and pregnant women—delayed treatment can lead to serious complications like pneumonia, seizures, brain damage, or even death.
Therefore, self-recovery is not recommended. If symptoms appear, it is important to seek medical attention as soon as possible.
How to prevent Pertussis?
The Pertussis vaccine is currently the only proven method of prevention. Common types of vaccines include:
Routine childhood vaccinations (DTPa)
- The Pertussis vaccine is typically administered as a combination with diphtheria and tetanus (DTPa).
- Under 'Hong Kong Childhood Immunisation Programme', it is recommended to vaccinate at 2, 4, 6, and 18 months of age, and again in Primary One.
Vaccination for pregnant women (Tdap)
- Pregnant women should receive the Tdap vaccine between the 28th and 32nd week of pregnancy. This helps transfer protective antibodies through the placenta, offering newborns early protection after birth.
- This practice is recommended by the World Health Organization (WHO) and various national health authorities.
Booster shots for adults and the elderly
- Although most adults were vaccinated during childhood, immunity decreases over time.
- It is advised to receive a Tdap booster every 10 years, especially for: family members of newborns, teachers, healthcare workers, and elderly caregivers, and trravellers planning to visit regions experiencing outbreaks
Protect yourself against Pertussis– Travel with peace of mind
In light of the rising number of Pertussis cases in Japan, travellers should take additional precautions beyond ensuring that they and their travel companions are up to date with their vaccinations and take the following precautions:
- Wear a mask: Use a face mask in crowded places to reduce the risk of infection.
- Avoid crowded areas: Minimise visits to high-traffic locations such as schools.
- Practise good hygiene: Wash hands frequently and avoid touching your eyes, mouth, and nose.
In addition, purchasing travel insurance is an essential part of safeguarding your trip—especially during an outbreak of severe pandemics. The medical coverage in travel insurance will be your strongest support while exploring Japan, allowing you to receive assistance more quickly in the event of an accident, ensuring peace of mind during your trip. However, how should we choose the right travel insurance?
Medical coverage in travel insurance: What to consider?
When evaluating the medical coverage offered by travel insurance, it's essential to focus on the following aspects:
1. Medical care expenses: In the event of an accident or illness during your travels, comprehensive medical insurance typically covers related expenses such as doctor's fees, hospitalisation costs, surgical fees, and more.
2. Emergency services: Travel emergencies may necessitate immediate medical attention. A reliable insurance plan should cover expenses for emergency services, including treatment in emergency rooms and ambulance fees.
3. Medical evacuation: In situations where local medical facilities are inadequate, or if no medical services are available, and evacuation is required due to a medical condition, insurance should provide compensation for related expenses, including air ambulance transport to a suitable hospital or medical facility.
4. Prescription drug costs: If medication is prescribed by a doctor for treatment, reputable travel insurance usually covers the associated prescription drug expenses.
5. Ancillary medical services: When hospitalised abroad due to accidental injury or illness, individuals may require the aid of local translators or interpreters to overcome language barriers. Depending on specific conditions, insurance coverage should compensate for the expenses incurred in availing such services.
6. Medical follow-up: If follow-up treatments such as hospitalisation and physiotherapy are necessary for injuries sustained or illnesses contracted during the trip, your travel insurance provider should cover the corresponding expenses within a specified period after you return to Hong Kong.
Taking AXA SmartTraveller Plus as an example, it offers medical coverage of up to HKD 1 million, including medical expenses, hospital cash allowance, and follow-up treatments within 90 days of return from abroad. Additionally, if the insured person contracts an infectious disease2 outside of Hong Kong and is diagnosed within 7 days of returning to Hong Kong, the insured person can still claim compensation for medical expenses incurred in Hong Kong, even if there are no overseas medical expenses incurred, giving you greater peace of mind during your travels.
Moreover, to address the challenges associated with seeking medical assistance in unfamiliar locations, we have introduced additional features to our insurance plans. For annual cover customers, what included are free virtual medical consultation and coverage for medicine delivery to your door twice per policy year3, effectively alleviating concerns related to language barriers and the need for lengthy journeys.
How does AXA SmartTraveller Plus ensure your protection?
- Introducing our newly added service: Our annual travel insurance now includes a newly introduced virtual medical consultation service. This feature is particularly beneficial when travelling to select overseas destinations in Japan, Thailand, Vietnam, Singapore, and the Philippines. It offers free virtual medical consultation and cover costs for medicine delivery to your door twice per policy year.
- Peace of mind regarding medical expenses: Our coverage takes care of medical costs resulting from illness or accidental injury abroad, including follow-up medical treatments within 90 days of return from abroad4.
- Complete coverage for travel delays: Whether it's additional accommodation, transportation expenses, or unrecoverable event ticket fees due to your absence, our protection encompasses all these aspects.
- Assurance for long and short trips: Whether you're embarking on a single trip lasting up to 360 days or multiple trips within a year, each no longer than 90 days, our comprehensive strategies ensure that you have adequate protection.
- Safeguarding personal belongings: Accidental loss of personal items can be frustrating. That’s why our coverage extends to provide protection for baggage, clothing, wallet, documents, camera, mobile phone, watch, laptop computer, and more, providing you with peace of mind5.
- Cater wide range of age: For single journey, we welcome applications for insured persons as young as 30 days old, with no upper age limit.
- Family coverage: For single journeys, we provide free coverage for all children6 insured under the same policy with their parent(s). For annual cover, we provide an option to all parents and all their children to be covered under the same by paying one family premium, for ease of policy management and cost saving.
Preventing Pertussis starts with you
Pertussis is a preventable and manageable disease, but its high contagiousness and potentially serious complications must not be overlooked. With the ongoing rise in cases in Japan, travellers planning to visit the country should remain vigilant, take necessary preventive measures, and purchase travel insurance to safeguard against possible health risks. Being well prepared is the key to enjoying your trip to Japan with greater peace of mind.
1. Source of Information: Japan Institute for Health Security (https://id-info.jihs.go.jp/diseases/ha/pertussis/020/250422_JIHS_Pertussis_en.pdf)
2. Any kind of infectious disease which is publicly announced as such and requires quarantine by the government.
3. Applicable to selected cities in Japan, Thailand, Vietnam, Singapore and the Philippines.
4. Follow-up medical treatment in Hong Kong is subject to separate sub-limits. For details, please refer to the policy wording.
5. Baggage and personal belongings coverage is subject to a deductible; mobile phone coverage is only applicable to the Privilege Plan, and the compensation amount will be based on the final claims decision.
6. Children must be between 30 days and under 18 years old, named in the same policy schedule as their parent(s), and travelling together with their parent(s) for the entire trip; the benefit limits on medical expenses and personal accident for them is lower under this coverage, however there is an option to upgrade if desired.
The plan is subject to the terms, conditions and exclusions of the relevant policy contract. AXA reserves the final right to approve any application. For detailed terms, conditions and exclusions of the plan, please refer to the relevant policy contract.
No warranty or responsibility is assumed by AXA Hong Kong and our related or holding companies regarding non-infringement, security, accuracy, completeness, adequacy, reasonableness, fitness for a purpose or free from computer viruses in connection with the information and materials provided. AXA Hong Kong and our related companies and holding companies do not accept any liability for any loss, damage, cost or other expense, whether wholly or partially, directly or indirectly, arising from any error, inaccuracy or omission of the information and materials to the extent that such liability is not excluded by law.
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