Travelers are advised to prepare and take precautions due to a surge in mosquito-borne infections like dengue and malaria, returning to pre-pandemic levels. The U.K. Health Security Agency (UKHSA) issued a warning as cases have reached levels not seen since 2019.

Dengue is not usually serious but can be severe in some cases, with symptoms similar to flu.

Malaria causes fever, headaches, confusion and muscle pains among other symptoms, and can be fatal. You can not catch either infection from another person.

The majority of the U.K.'s registered cases were with people who caught the disease while traveling to South and Southeast Asia, particularly India.

There was also a spike in cases from Central America and the Caribbean, the UKHSA said.

"If you are making plans to travel abroad this year, please take a moment to prioritize your health and plan ahead," Dr. Dipti Patel, director of the National Travel Health Network and Centre, said.

"If you feel unwell, seek medical attention and ensure you inform your healthcare provider that you have been traveling recently."

Dr. Philip Veal, a consultant in public health at the UKHSA, said there are several simple steps a person can take to reduce the risk of infection, including using insect repellent, covering exposed skin and sleeping under a treated bed net.

"Even if you have visited or lived in a country before, you will not have the same protection against infections as local people and are still at risk," he added.

The Travel Health Pro website, which is supported by the UKHSA, provides information on health risks in countries across the world.

It recommends travelers should consult a GP, nurse, pharmacist or travel clinic four to six weeks before their trip for advice on vaccinations.

UKHSA also urged travelers to ensure they are fully up to date with their measles, mumps and rubella (MMR) jabs, especially if going abroad with children. It warned that returning from countries with a high circulation of measles could make any outbreaks at home worse.