The U.S. embassy in Yemen has advised against travel to the western coast of the Arab state due to an outbreak of dengue fever, a sometimes fatal disease.

“The World Health Organization has advised the U.S. embassy that a dengue fever outbreak has afflicted the port cities of Hodeidah and Mokha on the western coast of Yemen and the surrounding coastal area. Estimates of the number of cases vary,” the mission said in an advisory dated March 9.

“Yemen’s health services network does not have adequate resources to mount a mosquito eradication campaign, nor the resources to systematically identify and treat suspected cases when they occur,” it added.

The embassy advised against travel to the Hodeidah region until there were better estimates on the scale of the outbreak.

Yemeni officials were not available to comment, but a parliamentary committee has said there were reports of dengue fever and malaria in the poor country of 19 million people.

The health system in Yemen is ailing and the country does not have adequate health facilities.

Dengue fever is transmitted through the bite of Aedes mosquitoes infected with dengue virus. There is no specific treatment for dengue infection. Symptoms include high fever, severe headaches, backache, joint pains, nausea and vomiting, eye pain and rashes.