LAHORE: The World Health Organization (WHO) says every one minute a child dies of malaria.

Like other parts of the country, the World Health Day was also observed in Lahore on Monday. This year on the World Health Day, the world is drawing attention to a group of diseases that are spread by insects and other vectors known as “Vector Borne Diseases (VBDs)”.

The WHO says that vectors are organisms that transmit pathogens and parasites from one infected person (or animal) to another, putting health at risk, at home and during travel.

Dr Ala Alwan, WHO regional director for the Eastern Mediterranean, has outlined some of the main challenges of preventing VBDs, including the lack of vaccines to protect people against these diseases.

He said VBDs account for 17 per cent of the estimated global burden of all infectious diseases.

“Malaria is the most deadly VBD, causing an estimated 660,000 deaths in 2010,” he said, adding that every one minute a child died of malaria. Yellow fever and dengue fever are also fatal diseases; dengue fever is the world's fastest growing VBD with a 30-fold increase in disease incidence over the last 50 years.

Dr Alwan said though a vaccine did exist for yellow fever, there were an estimated 200,000 cases worldwide each year and about 30,000 of those with yellow fever will die, as there was no cure.

VBDs are common in tropical and sub-tropical areas where safe drinking-water and safe sanitation systems are not accessible.

“Pakistan, being a subtropical country, has a rich fauna of disease vectors that includes mosquitoes, sand flies, houseflies, biting midges, ticks, lice, mites, fleas, cockroaches and bed bugs which account for number of vector borne diseases,” he says.

Major VBDs in the country include malaria, leishmaniasis, dengue or dengue haemorrhagic fever (DHF) and crimean congo haemmorhagic fever. Malaria being the second most prevalent and devastating disease causes 16 percent of disease load of the country.

Leishmaniasis is also showing a rising trend in the country, particularly in Balochistan, Sindh and Federally Administered Tribal Areas. Since, 2005-2006, Pakistan is facing regular outbreaks of dengue/DHF across the country. This indicates the rising trend of vector borne diseases in the country.

Over the years, climate change, population movement, uncontrolled urbanisation, poor housing and lack of safe water and sanitation have all contributed to the spread of vector-borne diseases.

“In Pakistan, VBDs, particularly malaria and dengue always flourish after the monsoon season -- August to November. During these months, more than 80 percent of the VBDs cases of the country are reported every year,” Dr Alwan says.

In Pakistan, he said, the major malaria transmission period was July to November. The control interventions therefore must be implemented well before the disease transmission period.

The WHO says VBDs’ transmission can be interrupted through residual insecticides application, treatment of vector breeding and resting sites, personal protection (by using repellents, long lasting insecticidal bed nets etc.), better environmental sanitation, health promotion campaigns, and integrated vector management etc. Fogging has also been recommended as one of the best choices to control vector densities only during emergencies and has not been recommended as routine intervention.

In a message, Dr Ashraf Ali Khan, consultant of infectious diseases at the Shaukat Khanum Memorial Cancer Hospital and Research Centre, says rapid unplanned urbanisation, climate change and deforestation have created opportunities for vectors and the diseases to spread.

He said the poor urban planning perhaps also leads to inadequately screened housing, puddles of rainwater, forlorn water collected in containers that breed mosquitoes, global travel and industry all historically contributing to the spread of disease-causing microbes.

Quoting a report of the WHO, he said every year, more than 1 billion people were infected and over 1 million died from vector-borne diseases. In addition, disability, work hours lost as well as the strain on healthcare systems from these diseases are enormous as was made patently obvious in 2011.