Dengue, chikungunya in Delhi: Understanding and identifying mosquito-borne diseases!

Zee Media Bureau

New Delhi: Dengue, chikungunya and malaria are three types of vector-borne illnesses, posing severe health threats. Dengue and chikungunya are both viral infections commonly spread by the Aedes mosquito. The viruses are transmitted from one person to another by the bites of infected female mosquitoes.

While dengue fever is mostly spread by the Aedes aegypti, chikungunya virus is often spread by the Aedes albopictus. However, both types of mosquitoes can spread both diseases.

Malaria, on the other hand, is a parasitic infection transmitted by the anopheles mosquito. Malaria is transmitted to humans through bites by infected mosquitoes.

This year, the monsoon season has brought about a staggering increase in cases of vector-borne diseases such as chikungunya and dengue in Delhi. Until September 8, the city has recorded a total of 771 dengue cases and nearly 900 chikungunya cases.

Since the symptoms of these diseases are so similar, it may be quite difficult to make a conclusive identification without laboratory testing. But, there are few differences that can be used to distinguish the disease and avoid misdiagnoses.

Understanding dengue fever

The dengue infection can be asymptomatic (up to 40% to 80%), mild or cause a serious illness. If left untreated, it can cause death. Symptoms may also vary, depending upon the type of virus and the level of the patients' immunity.

The incubation period ranges from 3 to 14 days after the bite of an infected mosquito, and disease duration varies from 4 to 7 weeks.

Common symptoms include – high fever, headache, severe muscle pain (on the back, arms and legs), joint pain (on knees and shoulders), severe pain behind the eyes, skin rashes (usually on face and limbs), fatigue, nausea, low white cell count, loss of appetite, etc.

In severe cases of the disease, the symptoms may include – shock, breathing difficulty, heavy bleeding (such as nose and gum bleed or easy bruising), abdominal pain, vomiting blood, persistent vomiting, dizziness, hypotension (abnormally low blood pressure).

Understanding chikungunya fever

Majority of people infected with chikungunya virus become symptomatic (approximately 70%). The incubation periodranges from 2 to 12 days after the bite of an infected mosquito, with an average of 2 to 7 days. Disease duration varies from one to two weeks. But, symptoms such as joint pain may persist for weeks, months or even years (in the chronic phase of the disease).

Initial symptoms include – high fever, severe joint pain (on hands and feet), muscle pain, skin rashes (mainly on the trunk, hands and feet), headache.

Other symptoms may include – joint swelling, vomiting, fatigue, sore throat, conjunctivitis

photophobia (extreme sensitivity to light). Neurological damage is possible, but rare.

Although, chikungunya is rarely fatal, the virus can cause serious complications in aged adults (> 65 years), babies or people with underlying medical conditions such as hypertension, diabetes, or cardiovascular disease. The virus has been declared as an emerging global health threat.

Understanding malaria

Normally, incubation period varies from 7 to 30 days, depending on the specific parasite you're infected with. The incubation period may be longer if you're taking medicive to prevent infection or if you have some immunity due to previous infections. As per WebMD, the time between exposure and signs of illness may sometimes be as long as 8 to 10 months with P. vivax and P. ovale.

According to the Centers for Disease Control and Prevention (CDC), malaria symptoms can be classified in two categories: uncomplicated and severe malaria.

Symptoms of uncomplicated malaria may include – high fever, flu-like illness, headaches, shivering, sensation of cold, vomiting, sweats. Malaria, if left untread, may develop severe complications and die.

Severe malaria occurs when the infections are complicated by serious organ failures in the patient's blood or metabolism. It is a medical emergency and should be treated immediately and aggressively.

Symptoms of severe malaria include -fever and chills, abnormal behavior, impairment of consciousness, seizures, coma, severe anemia, acute respiratory distress syndrome or ARDS (a medical condition characterized by widespread inflammation in the lungs), low blood pressure, abnormalities in blood coagulation, acute kidney failure, hypoglycemia (low blood glucose

Treatment and prevention for dengue, chikungunya and malaria

Because there's no specific vaccine to prevent either dengue fever or chikungunya, treatment basically focuses on pain relief and rehydration. Patients are advised to take plenty of water and other fluids, and a healthy diet consisting of fruits and vegetables.

In the case of malaria, antimalarial drugs can be used to prevent the disease.

Since dengue, chikungunya and malaria are all transmitted by moquitoes, you can can take some wise precautionary measures to avoid getting mosquito bites that can make you become a victim of these diseases.