Taipei, One new confirmed case of indigenous dengue fever was recorded Tuesday in the southern port city of Kaohsiung and has been determined to be a secondary infection from an earlier cluster, indicating the outbreak has likely spread.
The newly confirmed patient is a woman in her 60s who lives in Sanmin District of Kaohsiung and developed symptoms of fever, headache, muscle pain and dizziness on Monday, the Centers for Disease Control (CDC) said Tuesday.
The woman was later determined to have been infected with the Type4 dengue virus, a strain of virus rarely seen in Taiwan compared to the Type1 and Type2 viruses more usual in indigenous dengue infection cases, according to the CDC.
CDC Deputy DirectorGeneral Chuang Jenhsiang said the patient has a stand at a local market and has not traveled abroad recently.
Based on the timing of the onset of symptoms and the woman's place of work and residence, the patient is believed to have been infected by vector mosquitoes that carried the dengue fever virus from other patients in the cluster outbreak in Sanmin District, Chuang said.
It has not yet been determined whether the patient was infected at home or the market where she works, he said.
The latest CDC data shows that as of Tuesday, there have been 21 confirmed cases of indigenous dengue fever in Taiwan this year, all in Kaohsiung, with 20 categorized as a cluster outbreak.
The data also indicates that as of Tuesday, 171 imported cases of dengue fever infection have been confirmed across the country, the highest in nearly 10 years.
Over 90 percent of the cases originated in Southeastern Asian countries, including 58 in Indonesia, 34 in Vietnam and 20 in the Philippines.
Commenting on the possible spread of the dengue fever outbreak, Chuang said it is difficult to stem outbreaks because there could be recessive sources of viruscarrying mosquitoes that are easily ignored.
In addition, constant rain over the past week might also have boosted mosquito breeding, he added.
At a CDC press conference on Tuesday, Hwang Jisen an associate professor at the University of Taipei who has been involved in dengue fever control projects for 23 years, warned of a major outbreak in Taiwan this year of the Type4 virus.
Everyone in the country is vulnerable to the risk of infection because the strain is relatively rare, he warned.
Source: Focus Taiwan News Channel