Small bite, big threat: WHO issues vectors alert

MANILA, Philippines - Disease-causing organisms, known as vectors, may bite small but they infect two billion people around the world every year and kill half of them, the World Health Organization (WHO) reported yesterday.

More than half of the world’s population is at risk of getting diseases such as malaria, dengue, leishmaniasis, Lyme disease, schistosomiasis and yellow fever transmitted by insects such as mosquitoes, flies and ticks and other vectors such as water snails, WHO said, noting these diseases are preventable.

On April 7, the health agency will celebrate “World Health Day” to highlight the serious and increasing threat of vector-borne diseases.

Dubbed “small bite, big threat,” the celebration calls for a renewed focus on vector control and provision of safe water, sanitation and hygiene tools, which are among the key strategies outlined in WHO’s 2011 roadmap for the control, elimination and eradication of neglected tropical diseases.

The 2011 roadmap was targeted for the period 2012 to 2020.

“A global health agenda that gives higher priority to vector control can save lives and avert much suffering,” said Margaret Chan, WHO director general.

Chan said simple and cost-effective interventions such as insecticide-treated mosquito nets and indoor spraying have saved millions of lives.

“No one in the 21st century should die from the bite of a mosquito, a sandfly, a blackfly or a tick,” she said.

Vector-borne diseases affect the poorest populations, particularly in areas where there is a lack of adequate housing, safe drinking water and sanitation.

Malnourished people and those with weak immune system are susceptible to these diseases.

WHO said the schistosomiasis, transmitted by water snails, is the most widespread of all vector-borne diseases, affecting almost 240 million people worldwide.

Children living and playing near water bodies infested with snails are vulnerable to this disease, which causes anemia and a reduced ability in learning.

WHO gave assurance that schistosomiasis could be controlled through safe and effective medicine, as well as improved access to safe drinking water and sanitation.

“Within the past two decades, many important vector-borne diseases have also reemerged or spread to other parts of the world,” WHO said.

This was attributed to environmental changes, increase in international travel and trade, changes in agricultural practices and rapid unplanned urbanization.

WHO cited for instance the mosquito-borne dengue, which has spread to at least 100 countries, putting at risk more than 2.5 billion people or over 40 percent of the world’s population.

Dengue has recently been reported in China, Portugal and in the US state of Florida.

Reports reaching WHO showed malaria reemerged in Greece for the first time in 40 years.

WHO said this requires the need to ensure that any malaria resurgence could be contained immediately.