Asia-Pacific Regional Summary
Report Date: November 2, 2025
Updated with latest surveillance data from WHO, CDC, ECDC, and ProMED
DENGUE, CHIKUNGUNYA, AND ZIKA IN ASIA-PACIFIC
Global Context for Asia
Asia-Pacific continues to experience unprecedented mosquito-borne disease activity in 2025. The region accounts for a significant portion of global dengue cases (estimated 1.5+ million), is the epicenter of emerging chikungunya outbreaks including the largest documented outbreak in China's history (16,000+ cases), and continues surveillance for Zika expansion. The combination of monsoon patterns, urbanization, and climate variability has created ideal conditions for Aedes vector proliferation across the region.
BANGLADESH
Last Updated: October 6, 2025
DENGUE:
• Total Cases 2025: 33,800+ cases (as of late September/early October)
• Deaths: 215 deaths (as of October 6, 2025)
• Comparison to 2024: 312% increase in cases - severe outbreak
• Primary Affected Areas: Dhaka, Chattogram
• Status: Ongoing dual crisis with chikungunya
• Total Cases 2025: 33,800+ cases (as of late September/early October)
• Deaths: 215 deaths (as of October 6, 2025)
• Comparison to 2024: 312% increase in cases - severe outbreak
• Primary Affected Areas: Dhaka, Chattogram
• Status: Ongoing dual crisis with chikungunya
CHIKUNGUNYA:
• Confirmed Cases: 785+ cases confirmed by Dhaka labs (January-July 2025)
• Geographic Focus: Initial detection in Chattogram
• Status: Active outbreak, emerging threat alongside dengue
• Confirmed Cases: 785+ cases confirmed by Dhaka labs (January-July 2025)
• Geographic Focus: Initial detection in Chattogram
• Status: Active outbreak, emerging threat alongside dengue
ZIKA:
• Status: No cases reported
• Status: No cases reported
Public Health Response: Enhanced surveillance systems activated, vector control intensified in major urban centers.
CAMBODIA
Last Updated: October 2025
DENGUE:
• Total Cases: 32,803 cases reported
• Deaths: 52 dengue-related deaths
• Status: Active surveillance ongoing
• Total Cases: 32,803 cases reported
• Deaths: 52 dengue-related deaths
• Status: Active surveillance ongoing
CHIKUNGUNYA & ZIKA:
• Status: Under surveillance
• Status: Under surveillance
CHINA (Guangdong Province)
Last Updated: October 22, 2025
DENGUE:
• Status: Seasonal dengue cases during monsoon period
• Cases: Under surveillance, declining trend expected post-monsoon
• Status: Seasonal dengue cases during monsoon period
• Cases: Under surveillance, declining trend expected post-monsoon
CHIKUNGUNYA - MAJOR OUTBREAK:
• Total Confirmed Cases: >16,000 cases (LARGEST OUTBREAK IN CHINA HISTORY)
• Outbreak Start: July 2025
• Geographic Epicenter: Foshan, Guangdong Province
• Case Distribution:
- Foshan: 3,600+ cases (initial epicenter)
- Guangzhou: Active transmission
- Shenzhen: Cases reported
- Other Guangdong cities: Ongoing surveillance
• Viral Characteristics: Asian lineage chikungunya
• Current Trend: Daily case numbers declining but surveillance continues
• Significance: First major temperate region outbreak of this scale, indicates potential for geographic expansion
• Total Confirmed Cases: >16,000 cases (LARGEST OUTBREAK IN CHINA HISTORY)
• Outbreak Start: July 2025
• Geographic Epicenter: Foshan, Guangdong Province
• Case Distribution:
- Foshan: 3,600+ cases (initial epicenter)
- Guangzhou: Active transmission
- Shenzhen: Cases reported
- Other Guangdong cities: Ongoing surveillance
• Viral Characteristics: Asian lineage chikungunya
• Current Trend: Daily case numbers declining but surveillance continues
• Significance: First major temperate region outbreak of this scale, indicates potential for geographic expansion
ZIKA:
• Status: No cases reported in 2025
• Status: No cases reported in 2025
Public Health Response: Intensive mosquito control efforts active, ongoing epidemiological investigation, enhanced surveillance in neighboring provinces.
INDIA
Last Updated: October-November 2025
DENGUE:
• Status: Cases reported across multiple states
• Active surveillance maintained by NCVBDC
• Status: Cases reported across multiple states
• Active surveillance maintained by NCVBDC
CHIKUNGUNYA - MAJOR OUTBREAK:
• Total Cases: >34,628 confirmed cases (as of November 2025)
• Geographic Distribution: Multiple states affected, particularly areas conducive to vector transmission
• Status: Ongoing outbreak with localized surges
• Significance: India remains the major chikungunya burden in the WHO South-East Asia region
• Total Cases: >34,628 confirmed cases (as of November 2025)
• Geographic Distribution: Multiple states affected, particularly areas conducive to vector transmission
• Status: Ongoing outbreak with localized surges
• Significance: India remains the major chikungunya burden in the WHO South-East Asia region
ZIKA:
• Status: Under surveillance
• Status: Under surveillance
Public Health Response: Enhanced surveillance and control measures, community awareness programs, healthcare provider training.
INDONESIA
Last Updated: Mid-2025
DENGUE:
• Total Cases: 67,000+ dengue cases (as of mid-2025)
• Deaths: 297 dengue-related deaths
• Trend: High transmission across multiple provinces
• Primary Affected Areas: Jawa Barat, Jawa Tengah, Jawa Timur (Java region)
• Status: Significant outbreak with high mortality rate
• Total Cases: 67,000+ dengue cases (as of mid-2025)
• Deaths: 297 dengue-related deaths
• Trend: High transmission across multiple provinces
• Primary Affected Areas: Jawa Barat, Jawa Tengah, Jawa Timur (Java region)
• Status: Significant outbreak with high mortality rate
CHIKUNGUNYA:
• Cases: 20,000+ suspected cases reported in 2025
• Geographic Distribution: Nationwide resurgence
• Status: Major resurgence after years of lower activity
• Cases: 20,000+ suspected cases reported in 2025
• Geographic Distribution: Nationwide resurgence
• Status: Major resurgence after years of lower activity
ZIKA:
• Status: Under surveillance, no active outbreak reported
• Status: Under surveillance, no active outbreak reported
Strategic Initiative: Indonesia targets zero dengue deaths by 2030 through comprehensive health system transformation. Currently implements integrated vector management across provinces.
LAOS
Last Updated: August 5, 2025
DENGUE:
• Total Cases: 5,615 dengue cases reported
• Deaths: 1 death
• Geographic Concentration: Vientiane accounting for nearly 50% of cases
• Trend: Significant improvement - 556 cases only in Jan-March period vs historical patterns
• Total Cases: 5,615 dengue cases reported
• Deaths: 1 death
• Geographic Concentration: Vientiane accounting for nearly 50% of cases
• Trend: Significant improvement - 556 cases only in Jan-March period vs historical patterns
CHIKUNGUNYA & ZIKA:
• Status: Under surveillance, no reports
• Status: Under surveillance, no reports
MALDIVES
Last Updated: April 30, 2025
DENGUE:
• Total Cases: 347 cases (as of April 30, 2025)
• Comparison: Down from 641 cases in same period 2024
• Trend: Decreasing
• Total Cases: 347 cases (as of April 30, 2025)
• Comparison: Down from 641 cases in same period 2024
• Trend: Decreasing
CHIKUNGUNYA:
• Total Cases: 78 confirmed cases
• Total Cases: 78 confirmed cases
ZIKA:
• Status: No reports
• Status: No reports
MALAYSIA
Last Updated: July 5, 2025
DENGUE:
• Total Cases: 32,299 dengue cases (January 1 - July 5, 2025)
• Deaths: 21 fatalities
• Trend: 58.6% DECREASE compared to same period 2024 - significant improvement
• Status: Positive trend in outbreak control
• Total Cases: 32,299 dengue cases (January 1 - July 5, 2025)
• Deaths: 21 fatalities
• Trend: 58.6% DECREASE compared to same period 2024 - significant improvement
• Status: Positive trend in outbreak control
CHIKUNGUNYA:
• Status: Sporadic cases only, no major outbreak
• Status: Sporadic cases only, no major outbreak
ZIKA:
• Status: Not reported
• Status: Not reported
NEPAL
Last Updated: July 31, 2025
DENGUE:
• Total Cases: 2,587 cases (as of July 31, 2025)
• Comparison: Significantly lower than 4,777 cases in same period 2024
• Trend: Declining year-over-year
• Total Cases: 2,587 cases (as of July 31, 2025)
• Comparison: Significantly lower than 4,777 cases in same period 2024
• Trend: Declining year-over-year
CHIKUNGUNYA & ZIKA:
• Status: No confirmed outbreaks
• Status: No confirmed outbreaks
PHILIPPINES
Last Updated: November 2, 2025
DENGUE:
• Total Cases: 140,000+ dengue cases in 2025
• Deaths: 437 dengue-related deaths (as of November 2, 2025)
• Trend: 40-75% increase compared to 2024
• Peak Activity: July-October 2025
• Geographic Distribution: Cases across multiple regions nationwide
• Status: Severe outbreak with high fatality rate
• Total Cases: 140,000+ dengue cases in 2025
• Deaths: 437 dengue-related deaths (as of November 2, 2025)
• Trend: 40-75% increase compared to 2024
• Peak Activity: July-October 2025
• Geographic Distribution: Cases across multiple regions nationwide
• Status: Severe outbreak with high fatality rate
CHIKUNGUNYA:
• Total Cases: 2,854+ chikungunya cases reported
• Trend: 381% increase from previous year average
• Status: Emerging concurrent threat with dengue
• Total Cases: 2,854+ chikungunya cases reported
• Trend: 381% increase from previous year average
• Status: Emerging concurrent threat with dengue
ZIKA:
• Status: No reports in 2025
• Status: No reports in 2025
Public Health Response: Department of Health (DOH) coordinating enhanced surveillance, vector control programs, and hospital preparedness across all regions.
SINGAPORE
Last Updated: August 15, 2025
DENGUE:
• Total Cases: 3,122 dengue cases (January-August 2025)
• Dominant Serotype: DENV-2 (circulating since 2023)
• Status: Controlled transmission through active surveillance
• Notable Initiative: Project Wolbachia showing positive impact on transmission reduction
• Total Cases: 3,122 dengue cases (January-August 2025)
• Dominant Serotype: DENV-2 (circulating since 2023)
• Status: Controlled transmission through active surveillance
• Notable Initiative: Project Wolbachia showing positive impact on transmission reduction
CHIKUNGUNYA:
• Total Cases: 17 cases (January-August 2025)
• Trend: >100% increase from 8 cases in same period 2024
• Status: Increasing but monitored
• Total Cases: 17 cases (January-August 2025)
• Trend: >100% increase from 8 cases in same period 2024
• Status: Increasing but monitored
ZIKA:
• Total Cases: 11 confirmed cases (as of mid-July 2025)
• Notable: 2 locally-acquired cases confirmed (Woodlands Street 11 & 32)
• Virus Detection: Persistent virus signals detected in mosquito surveillance samples
• Status: Ongoing surveillance for potential local transmission
• Total Cases: 11 confirmed cases (as of mid-July 2025)
• Notable: 2 locally-acquired cases confirmed (Woodlands Street 11 & 32)
• Virus Detection: Persistent virus signals detected in mosquito surveillance samples
• Status: Ongoing surveillance for potential local transmission
Public Health Strength: Singapore maintains robust surveillance systems and rapid response capabilities. Project Wolbachia-infected mosquitoes continue demonstrating efficacy in dengue suppression.
SRI LANKA
Last Updated: July 2025
DENGUE:
• Total Cases: 33,796 cases (Week 1-30, 2025)
• Comparison: Slightly higher than 2024 (32,301 cases), lower than 2023 (56,227)
• Status: Stable to increasing transmission
• Total Cases: 33,796 cases (Week 1-30, 2025)
• Comparison: Slightly higher than 2024 (32,301 cases), lower than 2023 (56,227)
• Status: Stable to increasing transmission
CHIKUNGUNYA - MAJOR OUTBREAK:
• Status: LARGEST OUTBREAK IN 20 YEARS (since ~2005)
• Timeline: Initiated in late 2024, continuing through 2025
• Viral Lineage: Indian Ocean Lineage (IOL) with unique mutations
• Key Scientific Finding: Genomic sequencing reveals mutations that enhance transmission efficiency via Aedes aegypti mosquitoes
• Significance: IOL variant with enhanced virulence potential represents new epidemiological threat
• Status: LARGEST OUTBREAK IN 20 YEARS (since ~2005)
• Timeline: Initiated in late 2024, continuing through 2025
• Viral Lineage: Indian Ocean Lineage (IOL) with unique mutations
• Key Scientific Finding: Genomic sequencing reveals mutations that enhance transmission efficiency via Aedes aegypti mosquitoes
• Significance: IOL variant with enhanced virulence potential represents new epidemiological threat
ZIKA:
• Status: No cases reported
• Status: No cases reported
Clinical & Scientific Response: Complete genomic characterization completed. Enhanced surveillance for long-term complications including chronic arthralgia monitoring.
THAILAND
Last Updated: October 31, 2025
DENGUE:
• Total Cases (November 2025): Approximately 3,550 total cases for year
• Deaths: 34 dengue-related deaths (as of July 31, 2025)
• Comparison to 2024: 63% of cases and 68% of deaths from equivalent period
• Trend: Declining compared to recent years - positive sign
• Total Cases (November 2025): Approximately 3,550 total cases for year
• Deaths: 34 dengue-related deaths (as of July 31, 2025)
• Comparison to 2024: 63% of cases and 68% of deaths from equivalent period
• Trend: Declining compared to recent years - positive sign
CHIKUNGUNYA:
• Total Cases: 320+ cases reported
• Geographic Limitation: Localized primarily to southern Thailand
• Status: Contained outbreak, no nationwide spread
• Total Cases: 320+ cases reported
• Geographic Limitation: Localized primarily to southern Thailand
• Status: Contained outbreak, no nationwide spread
ZIKA:
• Status: No cases reported
• Status: No cases reported
Public Health Achievement: Thailand demonstrates improving dengue control measures with declining case trends. Chikungunya containment successful through regional vector control.
VIETNAM
Last Updated: November 2, 2025
DENGUE - CONCERNING LATE 2025 SURGE:
• Major Cities: Ho Chi Minh City alone >25,000 cases
• National Total: 65,000+ cases reported (as of September 4, 2025)
• Current Trend (October-November): Sharp increase in major urban areas
• Peak Week: Ho Chi Minh City spike of 2,517 cases in August
• Hanoi Status: 336 cases reported in recent week with ongoing transmission
• Clinical Severity: Increasing reports of severe dengue among children and adults
• Deaths: 11 deaths reported (as of September 4, 2025)
• Significance: Autumn/winter surge represents concerning epidemiological pattern
• Major Cities: Ho Chi Minh City alone >25,000 cases
• National Total: 65,000+ cases reported (as of September 4, 2025)
• Current Trend (October-November): Sharp increase in major urban areas
• Peak Week: Ho Chi Minh City spike of 2,517 cases in August
• Hanoi Status: 336 cases reported in recent week with ongoing transmission
• Clinical Severity: Increasing reports of severe dengue among children and adults
• Deaths: 11 deaths reported (as of September 4, 2025)
• Significance: Autumn/winter surge represents concerning epidemiological pattern
CHIKUNGUNYA:
• Status: Under surveillance, no major outbreak reported
• Status: Under surveillance, no major outbreak reported
ZIKA:
• Status: Under surveillance
• Status: Under surveillance
Public Health Response: Vietnam Ministry of Health coordinating prevention campaigns, vaccination efforts, and outbreak management. WHO SEARO providing technical support for response.
REGIONAL EPIDEMIOLOGICAL OVERVIEW
Critical Developments in Asia-Pacific 2025:
1. CHINA'S HISTORIC CHIKUNGUNYA OUTBREAK (16,000+ cases)
• First major temperate region outbreak of this scale globally
• Guangdong Province epicenter with documented cases in major cities
• Represents potential for disease expansion to new geographic areas
• Epidemiological significance: Challenges historical understanding of chikungunya geographic limitations
2. SRI LANKA'S LARGEST CHIKUNGUNYA OUTBREAK IN 20 YEARS
• Indian Ocean Lineage (IOL) with novel mutations detected
• Genomic characterization reveals enhanced Aedes aegypti transmission efficiency
• Sustained transmission continuing into 2025
• Regional concern: IOL variant potential spread to Indian Ocean territories
3. SOUTH ASIA DUAL MOSQUITO-BORNE DISEASE CRISIS
• Bangladesh: 33,800+ dengue cases + 785+ chikungunya concurrent outbreak
• India: 34,628+ chikungunya cases with ongoing dengue transmission
• Pakistan: Chikungunya surge reported in Karachi region
• Complex epidemiology: Multiple diseases competing for surveillance and resources
4. SOUTHEAST ASIA SURGE - MULTI-COUNTRY ACTIVITY
• Philippines: 140,000+ dengue cases with 437 deaths + 2,854+ chikungunya
• Vietnam: Sharp autumn/winter surge with 25,000+ cases in Ho Chi Minh City
• Indonesia: 67,000+ dengue cases + 20,000+ chikungunya cases
• Combined burden: Over 227,000 cases in three major countries alone
5. VIRAL STRAIN EVOLUTION
• DENV-2: Dominant serotype in multiple countries (Singapore, regional spread)
• Indian Ocean Lineage (IOL): Enhanced transmission chikungunya in Sri Lanka, Indian Ocean
• Asian Lineage: New chikungunya outbreak in China (Guangdong)
• Scientific concern: Genetic changes may alter transmission dynamics
Positive Developments:
• Malaysia: 58.6% decrease in dengue cases - successful control measures
• Thailand: Declining dengue trend with improved case management
• Singapore: Project Wolbachia demonstrating measurable impact on dengue suppression
• Nepal: Year-over-year decline in dengue cases
• Laos: Significant improvement in early season case trends
Key Risk Factors for Asia-Pacific:
⚠ Monsoon patterns continuing to drive vector proliferation
⚠ Climate anomalies (La Niña effects) increasing rainfall
⚠ High viral circulation established across multiple countries
⚠ Vector populations at elevated levels in urban areas
⚠ International travel facilitating disease dissemination
⚠ Variable surveillance capacity across countries
PUBLIC HEALTH INITIATIVES IN ASIA
Vector Control: Intensive mosquito surveillance and control programs across all countries
Surveillance Enhancement: Real-time monitoring systems improving in most countries
Strategic Initiatives:
• Indonesia: Zero dengue deaths by 2030 program
• Singapore: Project Wolbachia - Wolbachia-infected mosquito releases
• Regional: Enhanced cross-border surveillance coordination through WHO SEARO
Data sources: WHO, WHO SEARO, WHO WPRO, CDC, ECDC, ProMED, National Health Authorities; Last updated 02/11/2025