Neglected tropical diseases

Experts call for strong leadership to control vector-borne diseases worldwide

Phenomenal spread of dengue represents unique challenges for 21st century
08 April 2014 | Geneva

Far greater political, public and scientific support provide opportunities to improve control of many vector-borne diseases, which are widely distributed worldwide. However, strong, coordinated leadership is needed to sustain interventions against many of these diseases, particularly dengue and other arboviruses.

“Dengue is a disease of the 21st century” says Professor Jeremy Farrar of the Wellcome Trust. “With trade and travel and particularly urbanization, migration of people, demographic shifts and mobility … and a beautifully adapted mosquito which will live in cities. The vector is a day-biting mosquito and is going to increasingly adapt to the environmental and ecological changes the world is witnessing.”

Prof. P. Holmes, University of Glasgow and Dr M. Chan, Director-General of WHO

Professor Farrar was speaking during a panel discussion on vector-borne diseases at the headquarters of the World Health Organization (WHO) in Geneva during World Health Day – celebrated on 7 April to mark its founding in 1947.

Also highlighted were some of the challenges facing vector-control in a fast-changing society. What is acceptable in some circumstances may not be acceptable in others. But vector control is possible through integrated approaches and allied to clinical and other epidemiological interventions.

“Not all vector control works” added Professor Farrar. “There needs to be public discussions about implementation of new methods of vector-control such as genetically modified mosquitoes. This requires engagement with the public as there’s no public health without public engagement.”

For many vector-borne diseases, including malaria, insecticide resistance poses a great challenge.

“We are in an arms’ race with mosquitoes and the better we do the vector control, the more pressure we put on them, the more likely we are to get resistance to pyrethroid, ” says Professor Janet Hemingway of the Liverpool School of Tropical Medicine, UK. “So although we’ve been very lucky having very good interventions, we’re now starting to face the issue of pyrethroid resistance.”

According to Professor Hemingway, the world needs to start working on new insecticides to replace pyrethroids before they start to fail. She lauded WHO’s efforts in taking the lead to manage global insecticide resistance, which if properly implemented in countries will hold off resistance for a number of years to come.

In her opening remarks, WHO’s Director-General Dr Margaret Chan spoke of the devastating effects of many vector-borne diseases and warned of dengue’s global spread, which has the potential to paralyse health systems and cause economic and social disruptions.

“We need to re-create the momentum for vector control and the fundamental capacities that underpin it. These include staff with technical expertise, strong surveillance systems and better laboratory infrastructure.”

Dr Chan called on the global community to be proactive and for the world to act by taking preventive measures well before an alarming situation deteriorates.

The panel discussion, chaired by Professor Peter Holmes, also heard remarks from many world experts, including the Minister of Health of Namibia Richard Kimwi, the Singapore Ambassador to Geneva, Ms Tan Yee Woan, Dr Ronald Rosenberg, Associate Director, CDC and Dr Mathias Schmale, Under Secretary General, International Federation of Red Cross and Red Crescent Societies.

More than half the world’s population is at risk from diseases such as malaria, dengue, Leishmaniases, Lyme disease, schistosomiasis and yellow fever, which are carried by mosquitoes, flies, ticks, water snails and other vectors.

Every year, more than 1 billion people are infected and more than 1 million die from vector-borne diseases.