Pertussis or whooping cough is one of those diseases that I never thought we will see again in our lifetime. It is an acute infectious disease caused by the bacterium Bordetella pertussis. The first outbreak was described by Guillaume de Baillou during the 16^th century and the organism was first isolated by Jules Bordet and Octave Gengou in 1906. (CDC)

I remember the first time that I was introduced to the disease during my medical school back in the early 90s at Kasturba Medical College in Manipal, India. We were all just arriving at the lecture hall for one of our public health classes. Our lecturer was sitting on the desk in front of the class waiting for all the students to trickle in. Suddenly, he started to have an uncontrolled cough, making this high-pitched sound along with the cough. If I remember correctly, he was coughing for almost a minute before he stops. All the students were confused and were about to rush to the front of the class to help him. As suddenly as he has begun, he just stopped coughing, he said that that was how a patient with whooping cough would sound like, and he continued, this is most probably one of the only times you will have this experience. This is because of the success of the vaccination programme around the world. The whole-cell pertussis vaccines were first licensed in the United States in 1914 and were available as a combined vaccine with diphtheria and tetanus toxoids as DPT in 1948. (CDC) The National Immunization Programme (NIP) in Malaysia which is integrated into the mother-and-child health services was introduced in the early 1950s. The DPT vaccine was first introduced in Malaysia in 1958.

The Star Newspaper, on the 28 Apr 2023 reported that the Health Ministry has warned about an increase in whooping cough cases and death in Sabah. The report quoted the Minister of Health that from January to April 27, 2023, Sabah recorded 76 cases with one death, of which 41 were Malaysians, 27 Filipinos and eight Indonesians.

Why are we seeing an increasing number of cases of Whooping Cough?

There are many reasons that may have given rise to the increase in the number of pertussis cases, particularly in Sabah. Sabah has a very interesting demographic, they have a large number of foreigners in Sabah. According to a report in March 2022, foreigners make up 23.7% of the total population of Sabah. A large number of migrants in the state may not have received the pertussis vaccination. The pertussis vaccination is part of the childhood immunisation programme that all Malaysian children received. Due to the large number of children who are not vaccinated, there is a higher risk for the disease to spread in the community. This is the reason healthcare professional recommends immunisations for all without taking into consideration their citizenship status. Even though we have received vaccination, vaccinated children are still susceptible to the disease. However, the disease will be milder as compared to those who did not receive vaccination. It is important for us to vaccinate all children to achieve herd immunity.

The other reason may be due to vaccine hesitancy. Vaccine hesitancy is a multi-layered phenomenon, which can be due to various factors such as the influence of anti-vaxxers, parents’ past experience of adverse events following immunization (AEFI), perceived religious prohibition, a belief that traditional complementary and alternative medicine (TCAM) use is safer, and pseudoscience beliefs.

What do we need to do?

It is important for healthcare providers to understand the complex nature of the current rise in the number of vaccine-preventable diseases in Malaysia and around the world. Vaccination should be provided free to all citizens and non-citizens alike. There should be no repercussions when undocumented individuals come to healthcare facilities for vaccinations. Healthcare providers play a vital role in communicating and convincing vaccine hesitancy parents and anti-vaxxers about the importance of vaccination.

The article was written by Victor Hoe. Part of the article appeared in the Star Newspaper on 30 April 2023 as a response by Victor Hoe.