Global Rise in Dengue Cases, Transmission and Treatment

Dengue cases have surged in India, with significant increases in Karnataka, Kerala, and Tamil Nadu. Check here Contributing Factors of Transmission of Dengue.

Table of Contents

Context: Dengue cases have surged in India, with significant increases in Karnataka, Kerala, and Tamil Nadu.

Current Statistics

In India:

India: 19,447 cases and 16 deaths as of April 30, 2024.
Kerala and Tamil Nadu: Leading in case numbers.
Karnataka: Initially reported 2,503 cases, now 7,840 cases and seven deaths, with 293 new cases reported on July 10 alone.

Globally:

According to the World Health Organization (WHO):

Over 7.6 million dengue cases are reported globally.
3.4 million confirmed cases.
Over 16,000 severe cases.
Over 3,000 deaths.
90 countries have active dengue transmission, though not all are formally reported.
Dengue is endemic in over 100 countries, primarily affecting regions in Africa, the Americas, the Eastern Mediterranean, South-East Asia, and the Western Pacific.
Asia accounts for around 70% of the global dengue disease burden.
Dengue is spreading to new areas, including Europe, the Eastern Mediterranean, and South America.

Contributing Factors

Monsoon Season: At least five countries, including India, are experiencing monsoon season, creating suitable conditions for Aedes mosquito breeding.
Urbanization and Population Movements: Key factors in the increasing burden of dengue.
Climate Change: Inducing shifts in weather patterns that affect vector-host interactions.

Dengue Transmission and Treatment

Transmission: Dengue virus is primarily transmitted through the bite of infected Aedes aegypti mosquitoes.
- Most cases are asymptomatic or mild; severe cases can include shock, severe bleeding, or organ impairment.
Symptoms:
- Acute febrile illness lasting two to seven days.
- Headache, retro-orbital pain, myalgia, arthralgia, rash, and hemorrhagic manifestations.
Treatment:
- Managed through symptomatic and supportive treatment, particularly in those without warning signs or complications.
Prevention: Dengue vaccine (CYD-TDV or Dengvaxia) is available (US approval: 2019).

Emerging Patterns in Dengue

The first epidemic of clinical dengue-like illness was recorded in Madras in 1780.
Dengue virus was isolated in India in 1945, with the first evidence of dengue fever reported in 1956 from Vellore district, Tamil Nadu.
Tamil Nadu has experienced dengue outbreaks every five years, with the last outbreak in 2017.
Seasonal Variation:
- Seasonal variation every five years due to the buildup of susceptible populations.
- Continuous cases throughout the year, with spikes if control measures are delayed.
Public Health Measures:
- Surveillance and immediate response are critical.
- Community empowerment and education are essential to control outbreaks.