FILE PHOTO: A Venezuelan health worker fumigates the Valle slum to help control the spread of the mosquito-borne Zika virus in Caracas, January 28, 2016. REUTERS/Marco Bello/File Photo

LONDON (Reuters) - A humanitarian crisis in Venezuela is accelerating the re-emergence of malaria, Chagas disease, dengue, Zika and other dangerous infectious diseases and threatens to jeopardize 20 years of public health gains, experts warned on Thursday.

In a review published in The Lancet Infectious Diseases journal, researchers said the worsening epidemics could spread beyond Venezuela’s borders, potentially causing a regional public health emergency.

“As well as the return of measles and other vaccine-preventable infectious diseases, the continued upsurge in malaria could soon become uncontrollable,” said Martin Llewellyn, a doctor and senior lecturer at Britain’s Glasgow University who led the review with researchers from Venezuela, Colombia, Brazil and Ecuador.

He said that with its health care system collapsing and a dramatic drop in public health programs and disease surveillance, vector-borne diseases - those transmitted by insects such as mosquitoes and ticks - are on the rise and have spread into new territories across Venezuela.

The country was declared by the World Health Organization to have eradicated malaria in 1961.

Llewellyn’s team analyzed published and unpublished data and found that between 2010 and 2015, Venezuela saw an estimated 359 percent rise in malaria cases. This was followed by a 71 percent rise between 2016 and 2017 because of a decline in mosquito-control activities and shortages in medication.

The review also found the crisis is having dramatic effects on other vector-borne diseases in Venezuela. Active transmission of Chagas disease, for example, is the highest seen in 20 years, and incidence of dengue fever has risen more than five-fold.

Outbreaks of two other mosquito-borne diseases - chikungunya and Zika - also appear to be increasing, the researchers found.

The researchers said their findings should also be seen in the context of mass emigration. With an average of 5,500 people leaving Venezuela every day in 2018, they said, neighboring countries face the risk of potential imports of infectious disease outbreaks.