Hanoi, March 21 : Vietnam has raised concerns over the spread of dengue fever after the Health Ministry recorded a jump in the number of cases, local media reported on Tuesday. The number of dengue fever cases in Vietnam in the first two months this year have more than doubled compared to the same period last year, said the Ministry, with most infections recorded in the southern and central provinces, reports Xinhua news agency. The mosquito-borne disease is an annual problem in the Southeast Asian country which recorded 361,813 cases and 133 deaths last year. The Ministry has issued a warning to local authorities, relevant agencies and healthcare facilities to closely monitor the situation and promptly take preventive measures so that they will proactively prepare resources for severe cases amid a possible spreading dengue outbreak. Dengue causes flu-like symptoms, and severe forms of it can result in internal bleeding. There is no specific treatment and no vaccine available yet. The breeding grounds for the disease are often found in water tanks and waste bins. Unsanitary conditions, warmer weather and heavy rain help the spreading of the infection. /IANS