ASEAN manufacturing output fell among all surveyed countries in August, with Myanmar accounting for the largest decline, according to the Manufacturing Purchasing Managers' Index survey released by IHS Markit on September 1.

The survey was mainly conducted in seven ASEAN countries: Singapore, Malaysia, Indonesia, Philippines, Thailand, Vietnam and Myanmar in the ASEAN region.

The ASEAN Manufacturing PMI stood at 44.5 in August, down from 44.6 in July. This is a sign that the ASEAN manufacturing sector is in a three-month slump, according to the survey.

"For the first time since May 2020, the decline in all seven member countries highlights the severe consequences of the increase in COVID-19 infections across the region and the expansion of lockdown programs. The highest rates of decline are seen in Myanmar, Vietnam and Malaysia,” said Lewis Cooper, an economist at the IHS Markit.

The decline in production of the seven participating countries began in May 2020, with the first decline in August. The deepest decline was seen in Myanmar, with a PMI of 36.5, according to the survey.

Vietnam was the second-lowest PMI with a score of 40.2, followed by Malaysia with a PMI of 43.4.

The PMI scores of other countries are as per following: 43.7 in Indonesia, 44.3 in Singapore and 46.4 in Philippines respectively.

Thailand's PMI fell further below 50 points in August, with the PMI at 48.3, the biggest drop in three months, but only a tenth of a drop.

The calculation of the Purchasing Managers' Index (PMI) is based on production, new orders, workplace, suppliers' delivery time and stockpiles.

The survey is based on original data collected from industry by the IHS Markit and sponsored by Japan-based Nikkei Media Group.