Dengue: Here are dos and don’ts to keep deadly mosquitoes at bay

Hyderabad: As rains elude Hyderabad, the incidences of vector-borne diseases have dropped considerably.

Medical and health experts point out that though sporadic cases of mosquito-borne ailments are being reported daily, the spurt in cases is somewhat less compared to previous years.

Dengue mosquitoes can bite even in the evenings

Contrary to the popular belief that the dengue-causing mosquitoes bite only during the daytime, these Aedes Aegypti species can bite both in the morning and the evening and lead to infection.

“These Aedes mosquitoes can bite anytime, especially between 6 AM to 10 AM and between 4 to 7 pm, though they rarely bite late at night. This species, which breeds in freshwater, also doesn’t buzz and bites silently. They are also called tiger mosquitoes due to the stripes on their body,” says Dr. S Vijay Mohan, senior consultant physician from Care Hospitals.

General physician Dr. P Saketha Reddy, who saw four dengue patients in the last week, says, “The best way to guard against these mosquitoes is to avoid their breeding by removing stagnation of water in the house and surroundings, avoid going to areas with stagnated water, using mosquito repellents with caution and using mosquito nets for children and the elderly.”

Symptoms and types of dengue

Explaining the various types of dengue fever, Dr. Vijay Mohan says, “These can be categorized as dengue fever (DF), severe hemorrhagic fever (DHF) that mostly causes bleeding from the brain or abdomen and the most dangerous Dengue Shock Syndrome (DSS), which is characterized by very low blood pressure, unconsciousness, the requirement for IV fluids. Dengue is a virus, which is transmitted to humans through the bites of these Aedes mosquitoes. The main symptoms include high fever or break-bone fever, severe body and joint pains, and weakness. The fever usually remains during the first and last three to four days. The middle period of no fever is considered the dangerous period when most complications like fall in platelets happen. When some patients have a severe fall in platelets or have very low BP, they require hospital admission, while the not-so-serious cases can be treated as out-patients.”

Platelet requirements

The normal platelet count is usually between 1.5 to 4.5 lakh per microlitre of blood. It is produced in millions in the bone marrow daily and is required for clotting blood in case of injuries or bleeding. Their life cycle is for about 10 to 14 days and remains in circulation till they die in the spleen. “However, the dengue virus kills all circulating platelets much before their life cycle is complete. So the bone marrow tries to produce more platelets to compensate for the loss. In the elderly, in children, in immune-compromised people, or in those with comorbidities, the bone marrow response is less. Therefore, they may require platelet transfusion when affected with dengue,” avers Dr Vijay Mohan.

“But depending on the number and potency of the dengue virus, the newly-transfused platelets may again be destroyed and therefore the platelet count may fall rapidly despite transfusion. Unless the platelet count drops below 20,000, it is not considered too dangerous necessitating a transfusion,” he explains.

New virus strains may show unique symptoms in patients

However, what can be a cause of worry are new strains of the dengue fever virus, causing unique symptoms. Dr. K Shiva Raju, senior consultant physician, and diabetologist, head of the department of Medicine at KIMS Hospital, Secunderabad, says, “People usually come with symptoms like high fever, back pain, severe headache and some require platelet transfusion. But recently, we had a case of a young woman from the Karkhana area, where she had rashes, she was mildly hemorrhagic with bleeding from the eyes, had vomiting and nausea medicines were not working. Such symptoms seem to indicate new strains of the virus though further tests and more cases can confirm it.”

“We notice secondary complications, a tendency towards bleeding. The inflammation marker Ferritin in the blood is elevated in some patients. We, therefore, advise patients that if the high fever doesn’t subside within 48 hours, they must do NS1 or CBP blood tests to detect the dengue virus without delay to avoid complications. As the rains increase, we are likely to see more cases of vector-borne diseases,” avers Dr Shiva Raju.

GHMC’s measures to control vector-borne diseases

Chief entomologist of Greater Hyderabad Municipal Corporation (GHMC) Dr A Rambabu said that most of the dengue cases are being reported from the Charminar area in Old City and Karkhana area in Secunderabad.

Dr. Rambabu said GHMC is taking up all precautions for effective surveillance and control of mosquito breeding and the spread of vector-borne diseases.

A total of 2,375 staff is working for Vector Control Operations (VCO) in GHMC.

“We are conducting anti-larval operations (ALO) twice in all identified chronic breeding sources like construction sites, schools, function halls, cellars, open plots, and locked houses. We have identified 4,846 colonies, taking regular Anti larval and anti-adult mosquito measures (fogging, IRS, and Pyrethrum space spray) in all dengue-identified areas. Our Entomology wing is releasing Gambusia fishes in all small ponds and lakes and other stagnated water bodies as part of biological control measures. Releasing oil balls in all identified dirty stagnated points, ponds, nalas, etc. To reduce the mosquito menace in lakes and Musi River, spraying from drones is undertaken,” he said.

“Information, Education, and Communication (IEC) activities are being taken up regularly involving school children. Fever Survey, in coordination with the Medical and Health Department, was conducted in hot spot colonies where cases were recorded,” he added.

Dos and don’ts

- Avoid mosquito breeding by preventing water stagnation in the house and surroundings.

- Every few days, empty the water, which gets accumulated in flower pots, coconut shells, water coolers, tanks, and tubs.

- Avoid going to areas of stagnated water

- Use mosquito repellents with caution and even in the daytime if required,

- Use mosquito nets, especially for children and the elderly.

- If a high fever doesn’t come down within 48 hours despite taking paracetamols, get blood tests for dengue done without delay.

- If dengue is confirmed, take prescribed medicines, adequate rest, stay hydrated, eat light homemade food and unless it is severe or hospitalization is required, one usually recovers within a fortnight.