The southern frontier – confronting dengue in the south of Vietnam | World Mosquito Program Skip to main content

Published date: 14 Jul 2021 

Twenty miles upstream 

Coming from the busy bustle of Ho Chi Minh City, through the industrial, dusty outskirts of the sprawling metropolis, the city of Thu Dau Mot is surprisingly tidy.  Skirting the Saigon River, a bit over an hour’s drive from the heart of town, this burgeoning commercial district is still connected to town but without so much of the chaos and clutter. 

It’s well organised. The streets are a little wider. It’s busy but there’s room to breathe and shady places to rest. You sense there’s a collective pride from the local community in keeping their hometown laid back and livable. 

But as for many of Vietnam’s urban centres – particularly in the southern end of the country and particularly around the rainy season – the spectre of dengue casts a long shadow. 

Nguyen Thi Thanh Binh has lived here all her life. She talks about the generous spirit of her community, how her block is better kept than others and about the salty banh beo and mangosteen chicken salad that her town has made famous.


Twice a month we ask the residents here to clean around their homes and streets,” she says. “We even have government people come to check everything is clean. And we don’t want them telling us our neighbourhood is a mess!
Nguyen Thi Thanh Binh
Residential Leader
Ms Binh

Despite the efforts of the locals, there are plenty of empty blocks and construction sites that provide ideal breeding grounds for  mosquitoes. As a community leader and advocate for her residential area, Ms Binh knows her neighbours do what they can to keep the numbers down. But mosquitoes are notoriously difficult to control. 

“Any mosquito here carries the danger of transmitting dengue fever. If you get bitten, you are vulnerable,” she says. 

Employing every measure

Last year, one of the local health centres treated 220 cases of dengue. This year, numbers have been down, possibly due to less movement of people weary of COVID-19. But also, the rainy season has not yet arrived. 

Nguyen Van Hai moved to Thu Dau Mot – to his aunt's comfortable home down one of the many quietly looping lanes – from the countryside seven years ago. His ailing father was not able to get the medical treatment he needed so the family moved to where they knew they’d have better access to healthcare and schools. He works in Ho Chi Minh City, travelling by motorbike three hours a day, returning home in time to help put his two infant children to bed.  

A couple of months ago, Mr Hai and his wife got dengue. 

“It was very, very terrible,” he recalls. “First my wife got it. She had a high fever, 40 degrees. She was tired. She couldn’t eat any more. The first day she was feeling very cold. As you can see, the weather here is hot but she was feeling very cold. She thought she had the flu.” 

This is a common misconception of people who have contracted the virus. Many will endure the symptoms at home so the number of treated cases doesn’t come close to representing that actual number of people who have the disease. But by day three of her fever, Mr Hai took his wife to hospital. 

“Our baby is very young, still feeding from her mother. But my wife wasn’t eating. I remember one day we used the medicine six or seven times to try to reduce the fever, but it’s too much. And the fever did not decrease. We were worried about that. We knew this was dangerous, life-threatening if we didn’t go to the hospital. We moved the whole family to the hospital. We used a private room. It was so expensive but we had no choice.”

Two weeks later, Mr Hai got dengue too.

“After 4 days I’m feeling very very hot inside. I’m feeling terrible. Using medicine to decrease the fever. But it’s not enough. I cannot sleep. Only a few hours a day. The doctors came to check the fluid in my body. More time away from work. Luckily I could use my annual leave. I worried about the children getting infected. The feeling is terrible, I know it’s a feeling the children cannot experience. That’s why I try my best to keep the mosquitoes far away from my children.”
Nguyen Van Hai
Resident, Thu Dau Mot
Mr Hai

An indiscriminate burden

Dengue is the world’s fastest growing tropical disease. All of the world’s tropical regions are vulnerable. And those tropical regions are getting larger due to climate change. According to the World Health Organisation, nearly half of the world’s population is now at risk from dengue. 

The Aedes aegypti mosquito, most responsible for transmitting viruses like dengue, likes to live where people live. Which means some of the most densely populated cities in the world are hotbeds for the spread of the diseases they carry.

In Vietnam, dengue is endemic throughout the southern region and central coast. On average, more than 90,000 cases are recorded every year – 70% of them in the south. But hundreds of thousands more cases will go undetected. For some, the symptoms can be severe and dengue does not discriminate between rich or poor, young or old. 

Dr Huynh Trung Trieu is Deputy Head of the Pediatric Intensive Care Unit at the Hospital for Tropical Diseases in Ho Chi Minh City. Of the three to four thousand children a year who come to the hospital for treatment, around four hundred will experience shock and require intensive care under the management of Dr Trieu. 

Dr Trieu
Picture credit: Pearl Gan for The Lancet

“When a patient comes to PICU with shock, it’s hard to explain to the family immediately how severe they are and to predict the outcome, Dr Trieu says. 

“They are always very worried. We have to ask the parents to leave their child in intensive care and to wait outside the unit. They’re in tears and I have to ask them to trust me and that I will take care of them and inform them of the progress. This is hard if I have a night with 15 children in shock. I have to explain quickly that if they don’t hear from us then the child is ok. But if they become more severe I will call them.”

Dr Trieu’s patients receive a meticulously measured amount of fluid. Knowing when to give more, when to give less and when to stop is something of an art. The vast majority of cases will recover, but if the child has been admitted too late there can be significant organ damage and the child may die. 

“They don’t die immediately like with cardiac arrest. With shock it doesn’t happen like that. So we have to explain to the family gradually to try to help them accept the situation. If you come out and say ‘your child is going to die’ nobody will believe you. They can’t accept that their child has died after just several days with a fever. It’s painful for the family and painful for the staff. Every death you remember forever. So the feeling of seeing a patient discharged is something of more value than anything for a doctor.

If you come out and say ‘your child is going to die’ nobody will believe you. They can’t accept that their child has died after just several days with a fever.
Dr Trieu

A new day dawning

The World Mosquito Program has been working in Vietnam since 2006. 

The first trials of the Wolbachia method have been taking place near Nha Trang about 400km north of Ho Chi Minh City on the central coast. The most recent data is promising with far fewer cases of dengue being recorded in areas where Wolbachia mosquitoes have been released.

Nha Trang bike

While monitoring of this region continues, plans are in place to begin implementing the method in My Tho in the northern reaches of the Mekong Delta and in Thu Dau Mot. Together with partners at the Pasteur Institute, Action On Poverty  and with support from local government the first phase of the roll-out will focus on community engagement. Only when the communities are up to speed and on board will the first release get the green light to go ahead. This is where community leaders like Ms Binh and residents like Mr Hai play a crucial role. 

“The program has approval from the department of health so that’s why I trust it,” Ms Binh explains. “We need to believe in the public health department if we want the best outcomes for our country.”

Mr Hai, who has been following the progress of the Wolbachia method for some time, is equally supportive. 

“This method to use the mosquito against the mosquito is a very good idea. Especially in places where the health system is not so good. Here in the cities we have more access to treatment for dengue but in some places it’s very hard to get to hospital and they don’t have the money for treatment. It’s very exciting not only for me and my family and my neighbours, but for all people in Vietnam.”

Mr Hai knows that not all of his neighbours have the luxury of annual leave or the money to pay for a room in a hospital. He understands the burden a family like his can endure when the fever takes hold. He hangs nets over the beds in every room in his house, monitors the bathrooms for tiny intruders and prays that his two young children will be spared the suffering a single bite can bring.


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