Vector-borne disease

M A Jabbar :
World Health Day is celebrated on April 7 every year to mark the anniversary of the founding of the World Health Organisation (WHO) in 1948. Each year a theme is selected that highlights a priority area of public health.
The Day provides an opportunity for individuals in every community to get involved in activities that can lead to better health. The topic of world health day for 2014 is vector-born disease. Small bites can be a big threat.
Vector-borne diseases are infectious diseases spread by intermediate organism, such as insects and snails that transmit viruses, parasites and bacteria to humans. These diseases cause a high burden of illness and death for individuals, their families and communities specially in poorer countries, they lead to school absenteeism, worsening of poverty, a negative impact on the economic productivity, high health costs and overloaded health systems in countries. They are most commonly found in tropical areas and places where access to safe drinking-water and sanitation systems is problematic.
According to WHO the most deadly vector-borne disease- malaria, caused an estimated 660,000 deaths in 2010. Most of these were African children. However, the world’s fastest growing vector-borne disease is dengue, with a 30-fold increase in disease incidence over the last 50 years. It has become a major international public health concern in recent years. Dengue is found in tropical and sub-tropical regions around the world, predominately in urban and peri-urban areas.
Dengue haemorrhagic fever (DHF), a potentially lethal complication, was first recognized during the 1950 and is today a leading cause of childhood mortality in several Asian countries. The theme of the world health day this year, as such, is very timely appropriate.
WHO key fact shows that dengue is a mosquito-borne viral infection, which causes flu-like illness and occasionally develops into potentially lethal complications called severe dengue and its global incidence has grown dramatically in recent decades. About half of the world’s population is now at risk from dengue, which is found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas. Severe dengue is a leading cause of serious illness and death among children in some Asian and Latin American countries. The facts reveal that there is no specific treatment for dengue/severe dengue, but early detection and access to proper medical care lowers fatality rates below 1%. Dengue prevention and control solely depends on effective vector control measures.
According to WHO, the incidence of dengue has grown dramatically around the world in recent decades. Over 2.5 billion people – over 40 per cent of the world population are now at risk from dengue. WHO currently estimates there may be 50-100 million dengue infections worldwide every year.
WHO data further shows that before 1970, only nine countries had experienced severe dengue epidemics. The disease is now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, South-east Asia and the Western Pacific. The American, South-east Asia and the Western Pacific regions are the most seriously affected.
The Institute of Epidemiology Disease Control and Research (IEDCR) and the Centre for Communicable Diseases, ICDDR,B conducted a hospital-based study measuring the prevalence of dengue and malaria in six disctrics (Rajshahi Medical College Hospital, Khulna Medical College Hospital, Barisal Sher-e-Bangla Medical College Hospital, Kishoreganj Jahurul Islam Medical College Hospital, Chittagong Bangabandhu Memorial Hospital, USTC and Sylhet Jalalabad Ragib-Rabeya Medical College Hospital) in Bangladesh from 2008 to 2009. The study team confirmed four malaria and 69 ELISA positive dengue cases. Dengue was equally prevalent in urban (51%) and rural areas (49%) and most common (19%) during the post monsoon season (September-October). The study revealed that in Bangladesh dengue is common in urban and rural areas throughout the year. According to the study, physicians and health workers in rural areas should be trained in effective management of dengue patients with adequate dehydration and judicious use of antibiotics. Healthcare provides in Bangladesh should consistently use malaria diagnostics to ensure accurate diagnosis of febrile illness and avoid in appropriate use of anti-malarial drugs.
Globalisation of trade and travel and environmental challenges such as climate change and urbanization are having an impact on transmission of vector-borne diseases, and causing their appearance in countries where they were previously unknown. In recent years, renewed commitments from ministries of health, regional and global health initiatives- with the support of foundations, non governmental organizations, the private sector and the scientific community – have helped to lower the incidence and death rates from some vector-borne diseases.
World Health Day 2014 will highlight some of the most commonly known vectors-such as mosquitoes, sand flies, bugs, ticks and snails-responsible for transmitting a wide range of parasites and pathogens and attack humans or animals.
The campaign of the world health day April 7, 2014 aims to raise awareness about the threat posed by vectors and vector-borne diseases and to stimulate families and communities to take action to protect themselves. A core element of the campaign will be to provide communities with information. As vector-borne disease begin to spread beyond the countries where these diseases currently thrive. The campaign programme also aims at:
I. Families living in areas where diseases are transmitted by vectors know how to protect themselves
II. Travellers know how to protect themselves from vectors and vector-borne diseases when travelling to countries where these pose a health threat
III. In countries where vector-borne disease are a public health problem, ministries of health put in place measures to improve the protection of their populations, and
IV. In countries where vector-borne disease are an emergency threat, health authorities work with environmental and relevant authorities locally and in neighbouring countries to improve integrate surveillance of vectors and to take measures to prevent their proliferation.
Vector-borne diseases can be prevented by:
· Wearing cloth that acts as a barrier to exposure to bites
· Using mechanisms to keep vectors out of houses such as screens on doors, windows and eaves
· Reducing breeding sites near houses or in communities by: covering water storage containers, eliminating puddles and drainages of places where water accumulates, eliminating unusable containers where warier pools, and controlling refuse in yards and gardens.
WHO fact shows that at present the only method to control or prevent the transmission of dengue virus is to combat vector mosquitoes through: preventing mosquitoes from accessing egg-laying habitats by environmental management and modification, disposing of solid waste properly and removing artificial man-made habitats, covering, emptying and cleaning of domestic water storage containers on a weekly basis, applying appropriate insecticides to water storage outdoor containers, using of personal household protection such as window screens, long sleeved cloths, insecticides treated materials, coils and vaporizers, improving community participation and mobilisation for sustained vector control, applying insecticides as space spraying during outbreaks as one of the emergency vector control measures and active monitoring and surveillance of vectors should be carried out to determine effectiveness of control interventions.
Government of Bangladesh is cordial to combat vector-borne disease, which is reflected through its various programme undertaken by the Ministry of Health and Family Planning. WHO plays important role in this respect. It supports countries in the confirmation of outbreaks though its collaborating network of laboratories.
The collaborating networks in Bangladesh are ICDDR,B; BIRDEM and NIPSOM. WHO provides technical support and guidance to countries for the effective management of dengue outbreaks and supports to improve their reporting systems and capture the true burden of disease; provides training on clinical management, diagnosis and vector control at the regional level with some of its collaborating centres, formulates evidence-based strategies and policies, develops new tools, including insecticides products and application technologies, gathers official records of dengue and severe dengue from over 100 member states and publishes guidelines and handbooks for case management, dengue prevention and control for member states.
For effective vector-borne disease control we must work together. Green city/Green Bangladesh concept should be popularised. Along with Government and WHO efforts; health personnel, public representatives, social workers, NGOs, health workers, religious leaders, school teachers and individuals must work to raise awareness about the threat posed by vectors and vector-borne diseases and to stimulate families and communities to take action to protect themselves from the dangers of the disease.
The theme of world health day this year must be utilised in an appropriate manner. Working together we shall certainly win over the disease and thus keep community safe from the danger.