World Health Day: Stop Disease-Carrying Pests

A child in Madagascar receives bed nets for her family at a USAID distribution.

Washington — Mosquitoes, flies, ticks, water snails and other pests can carry diseases that sicken more than 1 billion people each year with malaria, dengue, leishmaniasis, Lyme disease, yellow fever and other dangerous conditions. Half the world — 3.6 billion people — live in areas where they risk exposure to what are known as vector-borne diseases.

The World Health Organization (WHO) is promoting awareness of these diseases in recognition of World Health Day April 7. Using the slogan “small bite, big threat,” WHO is hoping to increase awareness of how people can protect themselves from these pests and the sickness they may transmit.

“A global health agenda that gives higher priority to vector control could save many lives and avert much suffering,” said Dr. Margaret Chan, WHO director-general. “No one in the 21st century should die from the bite of a mosquito, a sand fly, a blackfly or a tick.”

In high-risk areas for malaria, distribution of bed nets to protect sleepers from mosquito bites has been an important factor in reducing disease occurrence. Spraying insecticide in and around homes, repellent use on the body and protective clothes are all further preventive measures.

Lack of clean water and adequate sanitation creates conditions where disease-carrying pests thrive. This is especially true for schistosomiasis, passed by water snails and flagged by WHO as the vector-borne disease affecting the most people worldwide. Almost 250 million received medication to prevent the disease in 2012, and more than 42 million were treated.

The role of pests in disease transmission has been known for more than a century, but WHO draws attention to the issue now because infections have become increasingly widespread in recent decades. Environmental changes, urbanization and international travel and trade are allowing microorganisms to reach places and populations where they previously were unknown.

Before 1970, for example, dengue fever, carried by mosquitoes, had occurred as a serious health problem in only nine countries. Now dengue is endemic in more than 100 countries across Africa, the Americas, the Eastern Mediterranean, South Asia and the Western Pacific, WHO reports. Nations reported a total of more than 2.3 million cases in 2010.

Sometimes known as “breakbone fever” because of the severe flu-like body pain it causes, dengue’s most severe form can be lethal, marked by severe vomiting, bleeding and difficult breathing. Currently, neither a vaccine nor a cure is known. Rest, fluids and fever-reducing medications are the only options for the ailing.

The dengue branch of the U.S. Centers for Disease Control and Prevention (CDC) is working on a vaccine, however. Located in Puerto Rico, CDC’s Dengue Branch is the largest research unit in the world working on prevention, treatment and control of this disease. In partnership with Inviragen, a company specializing in vaccine development, CDC has a vaccine candidate that has gone through clinical trials in Singapore, Colombia, Thailand and Puerto Rico. Analysis of the findings of those trials is underway, and the next phase of trials to measure the effectiveness of dengue protection is likely to begin toward the end of 2014, CDC reports.

The United States is also engaged in programs to combat malaria, the most deadly of the vector-borne diseases, killing 1.2 million per year worldwide, according to WHO. The Bush administration launched the President’s Malaria Initiative (PMI) in 2005, making a renewed commitment to a disease that causes both suffering and disability. Malaria has a role in perpetuating poverty in high-burden countries, economists say, because relapses and lingering effects can impair an individual’s ability to work and provide for family needs.

The almost 10-year accelerated campaign against malaria targets 19 high-burden countries in Africa and the Greater Mekong region, and it is estimated that more than 1.1 million lives have been saved from premature death so far. Distribution of bed nets and increasing the availability of medicines and care are important methods in lowering malaria’s toll. PMI has procured or distributed more than 120 million bed nets since 2006 and distributed more than 135 million doses of the combination drug therapy that treats the ailment.

Celebrating those achievements in 2013 on World Malaria Day, Secretary of State John Kerry said, “If we double down on our global efforts now, believe me, we have the ability to beat this disease.”

PMI also supports intensified research at the National Institute for Allergy and Infectious Diseases into treatment, diagnosis and vaccine development.

The United States supports further anti-malaria efforts through its ongoing support for the Global Fund to Fight HIV/AIDS, Tuberculosis and Malaria. United States contributions since 2001 have totaled about $8.5 billion, the largest amount given by any single donor nation.