Health agency reports 87,770 flu cases in August, with diarrhoea and Covid ranking next
Rabies led the case fatality ranking with one case and one death, while Thai officials urged stronger precautions against rising Covid infections
- Thailand's Department of Disease Control reported 87,770 influenza cases in August, making it the most common communicable disease for the month.
- COVID-19 ranked as the third most reported disease with 64,937 cases, behind influenza and diarrhoea (79,780 cases).
- Health officials noted that case numbers for both influenza and COVID-19 were continuing to increase.
- The case fatality rate for influenza was reported at 0.016%, which was described as being close to the COVID-19 rate of 0.02%.
Department of Disease Control (DDC) reported on September 15, 2026, that influenza was the country’s most frequently reported communicable disease in August, with 87,770 cases, while Covid-19 ranked third with 64,937 cases and was continuing to rise.
DDC senior physicians and spokespeople Dr Jurai Wongsawat and Dr Weerawat Manosuthi presented the figures at a briefing on September preparedness, disease prevention and health awareness. The department released separate rankings for the highest case numbers and the highest case fatality rates during August.
Five diseases with the most reported cases
DDC’s August ranking listed the following diseases. The cumulative figures accompanying the ranking cover January 1–September 8, 2026:
- Influenza: 87,770 cases in August; 376,531 cumulative cases in the ranking
- Diarrhoea: 79,780 cases in August; 795,579 cumulative cases
- Covid-19: 64,937 cases in August; 120,466 cumulative cases
- Pneumonia: 29,166 cases in August; 245,256 cumulative cases
- Hand, foot and mouth disease: 21,354 cases in August; 59,605 cumulative cases
Five diseases with the highest case fatality rates
DDC’s separate August ranking measured deaths as a proportion of reported cases:
- Rabies: One case and one death, a case fatality rate of 100%
- Legionnaires’ disease: Two cases and one death, a case fatality rate of 50%
- Melioidosis: 443 cases and 15 deaths, a case fatality rate of 3.39%
- Streptococcus suis infection: 106 cases and two deaths, a case fatality rate of 1.89%
- Encephalitis: 168 cases and two deaths, a case fatality rate of 1.19%
Covid cases rise, with infants recording the highest incidence
DDC reported 135,667 cumulative Covid-19 cases and 26 deaths through September 15, equivalent to a case fatality rate of 0.02%. The department said the caseload remained below levels seen two or three years earlier.
DDC said infections were continuing to increase, following its September 1 briefing on rising Covid-19 cases. Infants aged under one had the highest reported incidence.
DDC listed the following 10 provinces and Bangkok as the areas with the highest rates in its provincial ranking, measured in cases per 100,000 people:
- Chonburi: 747.32
- Bangkok: 687.31
- Phuket: 579.47
- Lamphun: 537.61
- Nakhon Pathom: 423.83
- Nonthaburi: 419.09
- Saraburi: 368.34
- Ang Thong: 314.67
- Rayong: 306.12
- Samut Songkhram: 289.80
DDC said older people and people with underlying conditions accounted for 21 of the 26 deaths. The most commonly reported underlying conditions were:
- Diabetes.
- Cerebrovascular disease
- Cardiovascular disease
- Chronic kidney failure
- Chronic respiratory disease
- Cancer
“Projections suggest there could be more than 20,000 cases a week if people do not wear masks, wash their hands frequently, keep their distance or ensure good ventilation,” Jurai said.
“If preventive measures can be increased by 50%, case numbers could be brought down quickly. An increase of 80% would bring an even faster and larger reduction. We project that this could keep the total for 2026 at no more than 300,000 cases, so we need the public to cooperate and follow the measures strictly,” Jurai said.
Influenza increases, while RSV poses risks to vulnerable infants
DDC’s detailed influenza update reported 57 deaths and a case fatality rate of 0.016%, which officials described as close to the Covid-19 rate. Influenza cases were continuing to increase.
DDC identified influenza A(H1N1) as the most commonly detected virus, followed by A(H3N2) and type B. The department said the influenza vaccine covered all three and could help protect against them.
DDC highlighted the following age patterns:
- Children aged five to nine had the highest number of influenza cases, with 65,300 reported
- People aged 60 and over had the highest reported mortality, accounting for 37 of the 57 deaths
DDC stressed that influenza vaccination remained important for people in risk groups.
DDC also reported 8,578 cases of respiratory syncytial virus (RSV) infection between January 1 and September 8, with one death. The patient was a two-month-old infant who had been born prematurely and had a low birth weight.
DDC identified premature birth and low birth weight as factors placing infants at greater risk of serious illness from RSV.
