China is boosting epidemic prevention measures against the West Nile virus, which recently prompted a public health emergency in Dallas County, Texas, the top border quarantine watchdog said on Tuesday.

Chinese border quarantine officers have enhanced inspections on travelers arriving from the United States, and offered advice on epidemic prevention to those leaving for the US, according to the General Administration of Quality Supervision, Inspection and Quarantine.

"The administration will pay close attention to the epidemic situation to prevent the virus from being introduced to China," Liu Hongsheng, a senior official from the administration, said on Tuesday at a regular media briefing.

The recent outbreak of the disease, said to be the largest ever seen in the US, had already infected 1,120 people and killed 43 across the country by Aug 25, according to the Xinhua News Agency.

First detected in the US in 1999, the mosquito-borne illness has infected more than 30,000 people in the country and led to serious neurological diseases in some cases, Xinhua said.

People infected with the West Nile virus suffer a sudden onset of fever, headaches, nausea, dizziness and muscle weakness.