Explaining the ongoing diphtheria surge in Vietnam

Hoang Minh Duc, head of the General Department of Preventive Medicine under the Ministry of Health, said diphtheria used to be prevalent in most Vietnamese localities.

In 1981, diphtheria vaccination was included in the national vaccination program, which is provided to children for free. The disease has been kept under control since, with only around 10 cases recorded each year within 2004-2019.

“The few cases of diphtheria every year due to unvaccinated people often happen in remote areas, where vaccination rates are low,” Duc said.

However, diphtheria has been returning in the past five years.

226 cases were recorded in 2020, mostly in localities like Dak Lak, Dak Nong, Gia Lai, Kon Tum, Quang Ngai and Quang Tri. There was a stark drop in the number of cases in 2021 and 2022, with six and two cases respectively, during the Covid-19 pandemic.

Just last year, Vietnam recorded 57 diphtheria cases, with the patients residing in Ha Giang, Dien Bien and Thai Nguyen. Among the cases, 55 of them were recorded within the last five months of the year, with seven deaths, a testament to the disease’s high infectivity and lethality.

This year, five cases have been recorded, with one death. Three of the cases were seen in Ha Giang’s former diphtheria hotspots, and the deceased patient was an 18-year-old woman in Nghe An. 134 people with relation to the deceased case have been quarantined as of Tuesday.

“There are still risks of community transmission. The important thing is those who have been in close contact need to be aware, quarantined, and to use antibiotics,” Duc said, adding that there was an ample supply of vaccines and antibiotics.

Truong Huu Khanh, vice head of the Infectious Disease Society of HCMC, said the surge of diphtheria cases was to do with “low vaccination coverage.”

The coverage of diphtheria vaccination among the community is currently at 93-95%. The hotspots have mostly been focused on remote areas with poor economic circumstances and low vaccination awareness. Traffic difficulties are also an obstacle to vaccine access.

“Due to its immunological characteristics, diphtheria usually infects slowly, meaning it does not spread as fast as other common respiratory diseases,” Khanh said.

Diphtheria is a bacterial disease usually encountered among children, but adults may also get infected if they have no immunity. It is capable of air transmission, with symptoms like a sore throat and white patches inside the throat. It may result in severe complications and even death.

There are vaccines against diphtheria, as well as antibiotics for treatment. Children can be vaccinated, but immunity will wane off over time, and booster shots are needed every 5-10 years.