For three continuous days, Asma Bibi was in agony; severe body aches, muscle pain, persistent migraines, fatigue, and a high fever. When she checked into the Benazir Bhutto Hospital (BBH) in Rawalpindi, her test reports revealed that she had contracted the 'breakbone fever', otherwise known as dengue. Given the manner of the virus's impact on the human body as it develops and unravels, her condition was expected to deteriorate.

20-year-old Bibi, who is six months pregnant, has spent two days in the high-dependency unit of BBH, where critical patients are treated.

Sitting on a bed covered with a blue mosquito net, Bibi tells Dawn.com, “I suffered from severe headaches, followed by vomiting and body pain. I lost my appetite and stopped eating at all.” While Bibi is hopeful of recovering soon, if not treated properly, dengue can be fatal.

A mosquito-borne viral infection, dengue is found in tropical countries worldwide and is transmitted through the bite of infected female mosquitoes that feed both indoors and outdoors during the daytime (from dawn to dusk). These mosquitoes thrive in areas with standing water, including puddles, water tanks, containers and old tires. Lack of reliable sanitation and regular garbage collection also contribute to the spread of these mosquitoes.

Dengue is quite common in South Asia, primarily occurring during and after the monsoon season from June to September.

According to Special Assistant to the Prime Minister (SAPM) on Health, Dr Zafar Mirza, the number of dengue cases in Pakistan has touched the five-digit figure and as many as 10,013 dengue cases have so far been reported this year from across the country.

Also read: Dengue returns

Official figures say that in Punjab, some 3,076 cases of dengue have been confirmed, out of which 2,730 have been reported from Rawalpindi alone. At least 9 deaths have been confirmed across three hospitals in the city during the past couple of months.

A measure of how widespread the dengue epidemic has become in parts of northern Punjab is manifested in the number of patients at outpatient departments of major hospitals across the region, many with complaints that indicate a developing dengue infection. The health infrastructure is struggling to cope.

Hospitals declare 'a state of emergency'

Doctors say this year the unprecedented surge of dengue has created fear and panic among people and that patients with simple headaches and body pains are flooding the hospitals.

“We are overburdened and there is no cooperation from private hospitals. Dengue in the Potohar region has become widespread, where routine wards are now being converted into dengue wards, which as a result is badly affecting other patients,” Dr Inayat ur Rehman, focal person for dengue at BBH, tells Dawn.com.

Rehman says the intensity of the virus this time around is 10 times higher than in previous years.

Due to a significant increase in the flow of patients, the hospital and laboratory staff remain on duty well into the late hours, testing blood samples and regularly monitoring critical patients.

Dr Faisal Shahzad, who supervises the ward in BBH — which is not usually reserved for dengue patients, says, “We have received more than 2,000 patients in just a few days, and each patient has to be monitored every 15 minutes. Our space is filled to the brim because of this deadly mosquito virus epidemic.”

Dr Qutbuddin Kakar, National Professional Officer, World Health Organization (WHO) for Vector-Born Diseases in Pakistan, says, “The recent spike in dengue is because of the heavy rainfall; weather conditions were favourable for the breeding of mosquito aedes aegypti in the Potohar region and the vector also expanded to other areas which were dengue free in the past."

"Apart from weather conditions, a heavy influx of people moving from dengue high-risk areas was another major reason for the spread of the vector. Due to this population movement, dengue is spreading to areas where it was not present earlier,” he says.

Speaking to Dawn.com, Punjab Health Minister, Dr Yasmin Rashid, says "The government is tackling dengue on an emergency basis and the situation is improving. We are liaising with private hospitals, and the Fauji Foundation Hospital is also facilitating dengue patients. Fumigation is being carried out in the places where the larvae is found and residential areas from where dengue cases have been reported. However, unnecessary fumigation should not be done as it leads to mutation of the virus."

Rashid added that "300 doctors and 200 nurses have been deputed in Rawalpindi alone for this purpose."

Once you've recovered, dengue can strike you again

Dengue infections are caused by four closely-related viruses named DEN-1, DEN-2, DEN-3, and DEN-4. A person suffering from one dengue type develops immunity from that particular virus strain after recovery. And when it comes to the remaining three types, the individual is only protected from infections resulting from them for two to three months after the first dengue infection. Once that short period is over, they can be infected with any of the remaining three dengue strains.

Researchers have observed that subsequent infections can put individuals at a greater risk of severe dengue than those who have never been previously infected. This severe infection — known as hemorrhagic dengue — can cause damage to organs and can also be fatal.

Explore: Experts emphasise awareness to check dengue outbreak

“Hemorrhagic dengue is dangerous and has affected people in Rawalpindi this season. I fear it will increase and will also move to other cities as people travel," says Dr Qaiser Sajjad, Secretary-General Pakistan Medical Association.

“A permanent strategy is required to decrease and eliminate the virus and measures should not be taken on an ad hoc basis. Permanent action should be devised with all stakeholders,” adds Sajjad.

The virus is evolving

A recent study says the virus is undergoing changes in its shape and is mutating, which is helping it evade the impact of vaccines and therapeutics.

Dr Sheemei Lok, professor at Duke-NUS Medical School and the corresponding author of this study, says different strategies need to be taken for different types of patients.

Lok says that in order to prevent the disease through vaccines that are administered before one contracts the infection, medics should use the vaccine that is effective against what is known as "the smooth surface virus".

"When it comes to patients displaying fever symptoms, treatment strategies effective against the bumpy surface particles should be implemented," she adds.

'A little too late to fumigate'

Dozens of health workers in Rawalpindi’s Dhoke Kala Khan area pump up their growling fumigation machines that appear similar to leaf blowers. The plumes of smoke have engulfed the entire street and residents are rushing to open their gates so the smoke can reach inside their houses.

Parveen, a resident of the area, says the municipality authorities should have sprayed earlier to avoid the worst of the outbreak. “This slum-like area is more prone to dengue and there have been many deaths reported here,” she says.

Read further: Is climate change increasing dengue risk?

Meanwhile, not so far from Dhoke Kala Khan, in Islamabad's Lohi Bhair, lives Khalid Naveed, who works as a security guard in Islamabad. He was brought to the BBH in critical condition. And although his mother says he appears to be recovering fairly well from the fever, Naveed has witnessed the rapid onset of dengue in at least eight other people in his neighbourhood. All of them, he says, have been admitted to BBH.

Naveed doesn't say whether the area had been fumigated against dengue, but a member of one of the fumigation team since the past several years says authorities should have started fumigation "well before the monsoon season began to avoid this situation".

Haroon Janjua is an award-winning independent journalist who covers Pakistan and Afghanistan. He tweets @JanjuaHaroon