Many people think of dengue as a mild disease and believe that severe dengue is rare. However, there is an estimated one in 20 cases where patients progress to severe dengue disease. As of July 20, 2024, the nationwide cumulative dengue cases stand at 83,131.
Given the high number of dengue cases, one in 20 doesn’t seem very rare at all. The consequences can be dire, as patients with severe dengue often require hospitalisation and face a higher likelihood of internal bleeding, plasma leakage, organ damage, respiratory problems, and even death. What’s more, the risk of severe disease is greater during a second infection.
In any case, statistics are of little comfort for those who suffer from the lingering effects of a severe dengue infection. This recognised but lesser-known phenomenon is referred to as post-dengue syndrome (PDS).
For Bahwanee Muthusamy, contracting dengue fever marked the beginning of a long and arduous journey that has lasted for more than six months, with no end in sight.
“This was my second time getting dengue fever; the first occurred about five years ago. Initially, I just had a mild fever, and the test done at the clinic didn’t detect dengue. I was told it was just a viral fever. However, by the next day, I developed a terrible headache, along with vomiting and diarrhoea, and my platelet count had dropped to 40.
“In fact, I felt so sick that I don’t even remember my trip to the hospital. My brother took me to the A&E, where they informed him that I was in critical condition; by then, my liver was already affected. I was so weak that I could not walk and was unable to eat for five days,” she recalled.
In total, Bahwanee was hospitalised for two weeks and remained on medical leave for another two months. During this time, she was unable to drive or even sit up for long periods due to compressed nerves in her lower back.
“Bahwanee’s experience is known as post-dengue syndrome, which refers to the clinical manifestations of dengue fever that persist for more than six weeks after the acute phase is over.
“It is unclear how commonly this occurs, but as it becomes more recognised, some studies have estimated its prevalence to range between 18 and 50 per cent,” explained Dr Shanthi Ratnam, Consultant Physician and Intensivist.
What is PDS?
Those who experience PDS are likely to have symptoms such as fatigue that can range from mild to overwhelming, musculoskeletal symptoms like muscle and joint pain, or swelling of the joints, known as reactive arthritis, as well as neurological signs like poor concentration or dizziness.
However, there is no specific test to definitively identify a patient’s symptoms as PDS.
This presents a challenge for both patients and healthcare practitioners.
At present, clinicians in the hospital are more likely to identify cases of PDS, explained Dr Shanthi. This is because dengue is often diagnosed by general practitioners, while clinicians usually perform follow-up care and are better able to note lingering symptoms.
“We conduct weekly follow-ups with patients for four weeks, by which time most of them are fully recovered. In rare cases, however, we encounter patients who suffer from symptoms for six weeks or longer,” she said.
Before diagnosing PDS, doctors need to consider many factors, including the patient’s medical history, and investigate any other causes that could lead to these symptoms. For example, secondary infections are common when a patient’s immune system has been compromised, while swollen joints could be caused by gout.
To help eliminate other possible causes, blood tests or imaging tests may be recommended. Only after excluding all other causes can a doctor conclude that a patient is experiencing post-dengue syndrome.
A long and arduous journey to recovery
For Bahwanee, her PDS has lasted for more than six months, and the ordeal is far from over.
“The whole experience has been a nightmare. It’s affected everything I do. Even simple things like climbing the stairs is a major exertion now, and I can’t work like I used to because I get tired too easily. To top it off, I’m dealing with hormonal issues and haven’t had my period since getting sick. Hair loss has been another major blow, I look like I went through chemo and had to cut my hair short. Also, my immune system is so badly affected that I fall sick easily; even antibiotics don’t help. As if that wasn’t enough, I also have asthma that seems to be flaring up more frequently,” said Bahwanee.
The consequences of PDS can also affect an individual’s mental health, added Dr Shanthi.
“Post dengue syndrome can severely affect a person’s quality of life, and the experience can cause a person to get depressed, especially those who had expected that their experience with dengue would be mild. For example, a young and active person may find it debilitating to be constantly tired, dizzy or in pain, have poor appetite and be unable to resume their normal activity for weeks or even months, by which time they would have experienced loss of muscle mass and other consequences of a long illness. Some patients may even be in denial, unable to accept these symptoms, as they would not have heard of PDS before,” Dr Shanthi explained.
Simply put, Dr Shanthi draws similarities between PDS and a tsunami — even though the attack has come and gone, the damage has been done, leaving behind chronic inflammation and an immune system that has become highly activated. Moreover, the effect is more profound if a patient has experienced dengue fever before; with four different strains of the dengue virus, a person could get infected up to four times, with the second infection having a higher likelihood of progressing to severe dengue.
Overall, Dr Shanthi said that elderly patients and those with comorbid conditions like hypertension, ischemic heart disease, obesity and autoimmune disease are more likely to experience severe dengue, which increases the likelihood of experiencing PDS. Among these, the elderly are also more likely to require high-dependency or intensive care as their health can deteriorate more quickly, with symptoms that linger for a longer period.
For those recovering from dengue, Dr Shanthi advised sufficient rest, with eight to 10 hours of sleep every night, and a balanced diet that is rich in fruits and vegetables.
Dr Shanthi also shared the following advice for caregivers to aid recovery of those in their care.
⦁ Children: While they tend to recover more quickly, it is advisable for them to stay home from school for a week before gradually resuming their normal activities.
⦁ Older persons: Encourage frequent napping and sufficient rest at night, as the body needs rest to repair itself, and older individuals take longer to recover.
⦁ Individuals with diabetes and hypertension: They are more likely to have very low blood pressure after their return from the hospital. As a result, they may not need to resume their medications immediately, or the dose may need to be temporarily adjusted. It is important to discuss this with their doctor to ensure close monitoring and follow-up.
⦁ Those at high risk for bleeding, such as individuals with ulcers, should be monitored for warning signs, such as dark, sticky stools.
Preventing dengue and PDS: What will it take?
As dengue is endemic in Malaysia, prevention is key, and experts advise a multi-pronged approach as there is no single method that is completely effective.
“Throughout my medical career, I’ve seen numerous methods employed to control dengue, yet cases continue to climb. We need to go back to the basics. For example, the rakyat as well as policymakers need to look into all the areas in which water accumulates, such as discarded containers and rain gutters — in Singapore, gutters are banned as they are a known mosquito breeding ground,” she said.
At the same time, she also cited a need to explore innovative preventive strategies such as the dengue vaccine, which was approved by the Ministry of Health Malaysia in February. This, she said, was something to consider, especially for those individuals with existing risk factors that can make the disease more severe.
Currently the dengue vaccine is available in private clinics and hospitals. The vaccine is given in two doses, three months apart. Dr Shanthi said that high-risk groups should consider vaccination. This includes the elderly who also have comorbid conditions, as they are more likely to require intensive care, individuals who are obese, and those with conditions like hypertension, ischemic heart disease and autoimmune conditions, as well as those being treated with medication that affect the immune system, such as steroids.
Those who have had dengue fever before, such as Bahwanee, may still take the vaccine six months later, to protect against subsequent infections with different dengue strains.
Dr Shanti added, “I think the dengue vaccine is going to help in many aspects, especially in reducing admissions in government and public hospitals, complications and deaths. While there are the usual queries about safety and efficacy, the research and development has been going on for a long time, and many countries such as Thailand, Indonesia and Brazil have already started using it, with Brazil including the vaccine into their national immunisation plan. I’m sure that, in time to come, people will grow to be comfortable with the dengue vaccine, just like all other vaccines, and the number of dengue cases will definitely come down.
“At the end of the day, we need to renew our commitment to fight dengue on all fronts,” she said.
Bahwanee echoes this sentiment, advocating for ongoing vigilance and a shift in public perception.
“Dengue is often dismissed as ‘just a fever’, but look at what happened to me. I am so glad there is a dengue vaccine now, because dengue is everywhere so no one is safe. This is why we need to take it seriously, and be proactive so we can combat this threat together.”
