Dengue early warning system predicts risk two months in advance

Dengue early warning system predicts risk two months in advance

Sub: Science

Sec: Health

• Indian Institute of Tropical Meteorology (IITM), Pune, in collaboration with other institutions, has developed an early warning system for dengue.
• The system predicts potential dengue outbreaks more than two months in advance. It uses observed temperature, rainfall, and humidity patterns for prediction.
• The system analyses climate-based dengue factors and their interaction with dengue at a regional level.
• Rising temperatures and fluctuating monsoon rainfall could increase dengue-related deaths in India by 13% by 2030 and 23-40% by 2050.
• Timely intervention is crucial to prevent India from becoming a dengue hotspot.
• Researchers have developed an AI/machine learning model to predict dengue outbreaks nearly two months in advance.
• This prediction capability allows authorities to improve outbreak preparedness.
• The early warning system provides time for local administration and health departments to enhance response strategies, reducing dengue cases and deaths.
• Sharing health data by state and health departments could enable customized early warning systems for other climate-sensitive diseases (malaria, chikungunya) at the city/district level.

DENGUE: A GLOBAL BURDEN

• Dengue is a fast-spreading mosquito-borne disease, exacerbated by climate change. India accounts for a third of the global dengue burden due to its high temperature and humidity, which are projected to increase.
• Erratic monsoon rainfall patterns, including heavy/extreme rains, contribute to warmer days, ideal for dengue outbreaks.
• Temperatures above 27°C, moderate/evenly distributed rainfall, and 60-78% humidity during monsoon season increase dengue incidence and mortality.
• June to September are high-risk months for dengue in India.
• Heavy rainfall (above 150mm/week) can reduce dengue by flushing out mosquito breeding sites. Pune’s average temperature is projected to rise by 1.2-3.5°C by the end of the century.
• Dengue mortality in Pune is projected to increase by 13% (2020-2040, 1.5°C warming) and 25-40% (2040-2060, 2°C warming).

DENGUE

• Dengue is a mosquito-borne viral illness caused by four distinct serotypes of the dengue virus (DENV 1-4). Infection with one serotype provides lifelong immunity to that specific serotype, but only temporary and partial protection against other serotypes. Subsequent infection with a different serotype increases the risk of severe dengue.
• Transmission: The primary vector is the Aedes aegypti mosquito, which typically bites during daylight hours. Other Aedes species can also transmit the virus. Transmission is primarily human-to-mosquito-to-human.
• Epidemiology: Dengue is a global health concern, especially in tropical and subtropical regions. India bears a significant portion of the global dengue burden.  Factors contributing to its spread in India include:
  • Favourable climatic conditions (high temperature, humidity, and rainfall patterns).
  • Rapid urbanization and unplanned development leading to mosquito breeding sites.
  • Inadequate sanitation and waste management.
  • Lack of awareness and community participation in vector control.
• Clinical Manifestations: Dengue presents a wide range of symptoms, from mild fever and headache (dengue fever) to severe manifestations like dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Severe dengue is characterized by plasma leakage, hemorrhage, and organ dysfunction.
• Diagnosis: Diagnosis is usually based on clinical presentation and laboratory tests. Serological tests (e.g., ELISA for IgM and IgG) are commonly used to confirm dengue infection.  RT-PCR can detect the virus directly in the early stages of infection.
• Treatment: There is no specific antiviral treatment for dengue. Management focuses on supportive care, including fluid replacement, pain management, and close monitoring for complications.  In severe cases, hospitalization and intensive care may be required.
• Prevention and Control: Integrated vector management is crucial for dengue control.
• Key strategies include:
  • Eliminating mosquito breeding sites (e.g., stagnant     water).
  • Using mosquito repellents and insecticide-treated nets.
  • Community mobilization and awareness campaigns.
  • Personal protection measures (e.g., wearing protective clothing).
  • Vaccination:  Dengue vaccines are available in some countries, including India, but their use is subject to specific guidelines and target populations due to serotype-specific responses.

Challenges:  Dengue control is challenging due to factors like:

• Climate change impacts on vector distribution and disease transmission.
• Increasing insecticide resistance in mosquitoes.
• Lack of a universally effective vaccine.
• Complex interactions between environmental, social, and economic factors.

Government Initiatives:  India has implemented various programs for dengue control, including the National Vector Borne Disease Control Programme (NVBDCP).  These programs focus on surveillance, vector control, case management, and community awareness.

• Recent Developments: Research is ongoing to develop improved diagnostic tools, antiviral therapies, and vaccines for dengue.  Early warning systems based on climate data and AI are also being developed to predict outbreaks and improve preparedness.