Los Angeles County reports a rare handful of local dengue cases

While Los Angeles County is reporting three locally acquired cases of dengue this year -- which is rare for the region -- there have been at least 3,085 cases nationally of locally acquired virus so far this year, according to data from the Centers for Disease Control and Prevention.

There has been about double the number of locally acquired dengue cases so far this year nationally compared to last year, according to the CDC. Puerto Rico currently makes up the bulk of those cases – with over 2,960 reported. The U.S. territory declared a public health emergency back in March.

"The City of Baldwin Park is aware of the recent cases of locally acquired dengue in our community. While the risk of transmission remains low, we must take this situation seriously and act proactively," said Mayor Emmanuel J. Estrada.

Dengue viruses spread through mosquito bites. The most common symptom is a fever with aches and pains, nausea, vomiting and rash. Symptoms usually begin within two weeks after being bitten by an infected mosquito and last 2-7 days. Most people recover after about a week.

Locally acquired cases mean that the people infected have no history of traveling to an area where dengue normally spreads. Local dengue transmission is typically common in tropical and subtropical areas of the world – including Florida, and U.S. territories in the Caribbean.

Last year, there were only two locally acquired cases reported in the state of California, the first local cases in the state reported in over a decade, according to CDC data.

The CDC issued a health alert in June warning health care providers of an increased risk of dengue virus infection this year. Globally, new cases of dengue have been the highest on record, according to the CDC. The agency also noted that cases are likely to increase as global temperatures increase.

The best way to prevent dengue is to avoid mosquito bites, according to the CDC.