Fiji's Ministry of Health is concerned at the rise in leptospirosis cases, urging people who show any symptoms to seek medical treatment immediately.
Since January this year, Fiji has had 42 cases of leptospirosis and caused four deaths.
For the same period last year, there were only 35 cases.
The infection is caused by bacteria called leptospira that is often found in domestic animals and in their subsequent environments.
Ministry spokesman, Peni Namotu, says humans can easily get leptospirosis through skin contact and consumption of contaminated food and water infected by the urine of animals.
He says common symptoms include body pains, blood clot eyes and fatigue.
"People have to present themselves to the health facility immediately if they develop symptoms and not go into some traditional medicine. Because this can not only avoid prolonged illness but also prevent fatalities. And most importantly the washing of hands."
Peni Namotu says parents must also supervise their children closely to ensure they don't play in contaminated areas and water, or come into contact with affected animals.