It is believed that the dengue fever mosquito landed in Pakistan in 1994 along with a consignment of tyres. It affected Karachi in 2005 and a major outbreak occurred in 2011 when around 27,000 people were infected with the disease.

In early 2019, the World Health Organisation (WHO) included dengue fever among the top 10 global public health threats. “Widespread dengue infections across the world are largely attributable to climate change. Currently, half of the world population residing in 125 countries is at risk,” it said.

Like many other countries in the region, Pakistan faced a dengue fever upsurge in 2019. The carrier mosquito can’t fly more than 100 metres in its lifetime of around 20 days. It is born in houses and lays eggs there or at nearby places.

Community awareness can create a major obstacle to dengue fever spread can reduces the number of cases. People should use mosquito repellents, cover their arms and legs, particularly before sunrise and after sunset. Those infected should not panic as the disease can generally be treated by having lots of fluids and fruits and controlling the fever.

When a carrier mosquito bites a person, it injects the dengue virus into the bloodstream. The virus infects nearby skin cells called keratinocytes, the most common cell type in the skin.

Dengue fever can lead to a severe flu-like illness. It is caused by four different viruses and spread by Aedes mosquitoes. The symptoms range from mild to severe. Severe symptoms include dengue shock syndrome (DSS) and dengue hemorrhagic fever (DHF).

The course of infection is divided into three phases: febrile, critical and recovery. The febrile phase involves high fever, potentially over 40°C (104 °F), and is associated with generalised pain and a headache; this usually lasts two to seven days. Nausea and vomiting may also occur. Symptoms of dengue fever include severe joint and muscle pain, swollen lymph nodes, headache, fever, exhaustion and rash.

In about 5 percent of people with dengue fever, the disease goes into a critical stage. The critical phase usually lasts for a day or two. During this stage, plasma (the liquid part of blood) can leak out of the body’s smallest blood vessels.

In about 5 percent of people with dengue fever, the disease goes into a critical stage. The critical phase usually lasts for a day or two. During this stage, plasma (the liquid part of blood) can leak out of the body’s smallest vessels.

The mosquito becomes infected when it takes the blood of a person infected with the virus. After about one week, the mosquito can transmit the virus while biting a healthy person. However, a person infected and suffering from dengue fever can infect other mosquitoes.

It can then spread the virus to other people by biting them. Dengue fever cannot spread directly from person to person. Since several viruses can cause dengue fever, someone can get the disease more than once. Dengue fever can be diagnosed by isolation of the virus, by serological tests.

Diagnosis of acute (on-going) or recent dengue infection can be established by testing serum samples during the first five days of symptoms and/ or early convalescent phase (more than 5 days of symptoms.)

Patients suffering from high fever are often put through a series of tests to detect the cause of fever. They end up spending a few thousand rupees on diagnostic tests (malaria test costs up to Rs 750 and the one for dengue costs up to Rs 4,500). What’s more, their treatment gets delayed pending confirmatory tests.

A flat, red rash may appear over most of the body two to five days after the fever starts. A second rash, which looks like the measles, appears later in the disease. Infected people may have increased skin sensitivity and are very uncomfortable.

Some develop dengue hemorrhagic fever after the initial fever declines — a more severe form of the illness that can cause organ damage, severe bleeding, dehydration and even death. But with early treatment, the mortality rate for all dengue fever is currently less than 1 percent.

There is unfortunately no vaccine or cure for dengue fever, so if you think you have it, rest, drink plenty of fluids and take a pain-reliever with acetaminophen and avoid medicines with aspirin, which could worsen bleeding. The symptoms and signs may last about one to two weeks with complete recovery, in most cases, in a few weeks.

Special attention needs to be given to these warning signs as it could lead to severe dengue:

u Severe abdominal pain.

u Persistent vomiting.

u Bleeding gums.

u Vomiting blood.

u Rapid breathing.

u Fatigue/ restlessness

If left untreated, dengue hemorrhagic fever is more likely to progress to dengue shock syndrome. Common symptoms in impending shock include abdominal pain, vomiting, and restlessness. Patients also may have symptoms related to circulatory failure.

Fruits: When not able to eat normal solid food, increase intake of fresh fruits such as banana, apple, pomegranate, citrus and guava. They help replenish minerals and vitamins lost in vomiting or as a result of high fever.

Protein rich food: Milk, egg and other dairy products must be consumed to battle with this virus. Non-vegetarians can go with the fish and chicken in a good quantity once they start recovering from the fever.

Soups: Hot soup intakes will enhance the strength and help fight the joint pain.

The best foods to recover from dengue fever are papaya, broccoli, which is an excellent source of Vitamin K and helps regenerate blood platelets, pomegranate, which is rich in essential nutrients and minerals, and spinach.

Some dengue patients start eating kiwi fruit or juice of papaya leaf or take goat milk. These fruits and milk strengthen the immune system and keep the patient hydrated. But if a dengue patient is having a lot of kiwi, his throat can get sour and develop some problem.

The writer is doing his PhD in Huazhong   Agricultural  University, China. He is a lecturer at the   University of Veterinary and Animal Science, Jhang. He can be reached at zahid.farooq@uvas.edu.pk