Samoa's Ministry of Health says four children have died and 19 have been left seriously ill this year due to malnutrition following diarrhoeal illnesses.
Dr Saine Vaai-Nielsen from the Ministry's surveillance team says she's issued a public health alert to family doctors as the situation is much worse than previous years.
She says multiple factors are behind the problem including poor feeding and hygiene practices.
She says the Ministry was alerted to the outbreak after recent doctors' meetings.
The National Health Services had reported to us within these meetings of four deaths of malnourished children. So we investigated and indeed it was correct.
Dr Saine Vaai-Nielsen says the Ministry is asking doctors to collect laboratory samples to find out which viruses or bacteria may be involved and to alert them to the importance of proper oral rehydration.