Dengue fever expansion — a challenge for planners to develop strategy for future

Islamabad: With well over 20,500 confirmed dengue fever cases and at least 45 deaths reported so far due to the infection in the twin cities of Islamabad and Rawalpindi, dengue fever outbreak has appeared as a greater health threat in 2019 putting a challenge for planners and authorities to develop a fool proof mechanism and achieve a better level of preparedness to deal with the infection’s expected outbreak in the coming year that might be far more aggressive.

Due to intense outbreaks of dengue fever in last four years and greater number of patients, the number of patients with more fatal forms of the infection remained much higher this year and, according to health experts, the same can be expected next time. If there are more confirmed cases in the current year, the chances of haemorrhagic manifestations would be greater in 2020 and onwards. Well over 37 per cent of confirmed patients of the infection reported in the region contracted dengue haemorrhagic fever or dengue shock syndrome, the more fatal forms of the fever this year that resulted in higher number of deaths.

With over 13,200 cases from the federal capital and over 8,300 cases from Rawalpindi, the outbreak remained much intense and obviously the situation demands exercising a high level of preparedness in the dengue high transmission season next year.

The trend of the outbreaks reveal that gradual distribution and expansion of dengue fever was seen from lower areas to upper areas of the country in last 10 years or so as the disease became endemic in Pakistan with periodic outbreaks and has spread to affect both urban and rural areas and is present in most parts of the country. Health experts say that the dengue fever expansion has special relation to climate, temperature, rains, congested population, infected population and human behaviour.

The main reason behind much intense dengue fever outbreak this year with over 51,000 confirmed cases from almost all across Pakistan is that the health departments did not take measures for prevention and control of dengue fever giving due attention to the scientific evidences generated through previous five years data and experiences.

Experts say that no significant efforts were made by the stakeholders to improve disease surveillance and case response specifically targeting areas where the disease had struck last year and for strengthening early warning and timely epidemiological response and capacity building. Dengue, which is the fastest emerging arboviral infection since 2005 in Pakistan, imposes a heavy economic and health burden on the country, families and individual patients. In the absence of an effective drug or vaccine, the only strategic options presently available are effective case management to prevent death and vector control to reduce viral transmission.

According to epidemiologist Dr. Muhammad Najeeb Durrani who is Member Global Outbreak Alert and Response Network (GOARN), scientifically, the best method to reduce transmission of dengue virus is to control population of vector mosquitoes particularly ‘aedes aegypti’ and to avoid mosquito contact.

In general, high humidity and temperature are conditions that favour dengue vector’s survival, increasing the likelihood of transmission that requires an infected traveler in the season. Human behavior plays an important role in spread and control of dengue. Congested living, presence of solid waste, trash, and poor water storage practices are the main reasons for poor control, he said. Mass transit or human travel is an important factor in spread and propagation of the disease to new areas.

Of preventive measures, he said during the off season in the beginning of winter, the main action against dengue vector should be spraying with insecticides, as dengue vector tries to fly from outside to inside homes and offices in search of relatively warmer places.

Stagnant water ponds and over flowing water in buildings is needed to be treated by temephos granules and during off season, inspectors from the vector control sections of the health departments should work hard for outdoor surveillance particularly at sites regarded as hot spots like solid waste dumps, junkyards, grave yards, tire shops, under construction and abandoned buildings, nurseries etc. on regular basis, said Dr. Durrani, former District Health Officer Islamabad.

He added it is time to take action to prevent mosquitoes to hatch from the eggs that have been laid in the start of winter season and these would be ready for the next summer to sprout and become adult mosquitoes to acquire infection by biting infected people and cause transmission of the disease.

To avoid dengue fever outbreak in future, it is a must to educate women and children in the community about safe water storage practices and keeping vigilance in their homes and around where rain water could be collected leading to mosquitoes breeding. Experts say that school children should be educated on regular basis through small and simple topics about preventive measures against dengue fever.