Health experts have sounded the alarm on the escalating public health crisis in the Philippines, warning that climate change is magnifying the spread of infectious diseases.
During the climate and health plenary at Eco-Business’ Unlocking capital for sustainability Philippines forum, Dr Ramon San Pascual, executive director of Healthcare Without Harm Southeast Asia, said that Filipinos are already feeling the bite of climate change, not just in property damage but also in the documented rise of deaths due to vector-borne diseases.
“The climate crisis is a health crisis,” said Dr San Pascual. “Whether it be [the increasing frequency] of extreme weather events or the slow but gradual change of our climate, the [adverse] impacts on the health of our public is becoming more prevalent.”
The medical experts noted that Department of Health (DOH) reports confirm vector-borne and zoonotic diseases such as dengue and leptospirosis surge in the aftermath of floods triggered by typhoons and heavy monsoon rains, disproportionately affecting congested urban populations.
“
Years of [infrastructure] development can become meaningless with just one day of disaster. Economic growth is hampered by adverse impacts, and that’s the reason why [these widescale] disasters happen, because we fail to anticipate these bigger extreme weather events.
Dr Alfredo Mahar Francisco Lagmay, executive director, University of the Philippines Resilience Institute
In Quezon City, for example, dengue cases reached 6,981 between January and August this year alone – a 155 per cent increase compared to the same period last year – as the metropolitan area has struggled with increased flooding. Children aged 10 and below were the most affected by dengue infections, according to city health officials.
Just this weekend, Quezon City was swamped by a deluge equivalent to five days’ worth of rain in the span of an hour. The torrential downpour left 36 out of the city’s 142 barangays [villages] flooded. The surge was fueled by a severe but short rainfall downpour, with local experts noting gaps in flood control planning.
The DOH has released advisories heeding Quezon City citizens to take extra precautions against flood-related illnesses, including requiring residents who had waded through floodwaters to consult with their local health centre immediately.
Leptospirosis, now classified as a climate-sensitive disease, have spiked during the country’s monsoon seasons, overwhelming hospitals in Metro Manila. Quezon City alone has reported 521 cases as of late August, up 26 per cent year on year, with 74 fatalities. Around 79 per cent of these infections were linked to exposure to floodwaters contaminated with bacteria carried by rats.
From 8 June to 7 August, the DOH recorded 2,396 leptospirosis cases nationwide, many of them concentrated in the capital region.
(From left) Dr Ramon San Pascual, executive director, Healthcare Without Harm SE Asia; Dr. Alfredo Mahar Francisco Lagmay, executive director, UP Resilience Institute; Dr Annabelle Sinlao, assistant professor, Manila Central University College of Medicine; and Dr Nicole Kranz, climate action and disaster resilience cluster coordinator, GIZ Manila, speaking at Unlocking capital for sustainability Philippines. Image: Eco-Business
The DOH has also reported a nationwide uptick in dengue this year, with more than 15,000 cases recorded in just two weeks in July after tropical cyclones Crising, Dante, and Emong created widespread breeding grounds for Aedes mosquitoes.
Other common vector-borne diseases in the Philippines include chikungunya, malaria and Japanese encephalitis, which are also transmitted primarily by mosquitoes.
Compounding the crisis is a seasonal shortage of preventive medicine during monsoon months, noted Dr Annabelle Sinlao, assistant professor, Manila Central University College of Medicine.
“Previously, we’ve [experienced] a scarcity of doxycycline [after widespread floods],” said Dr Sinlao during the same panel. “We [administer] that as a post-prophylactic measure when someone has been wading in [potentially contaminated] flood[waters].”
The antibiotic is used to reduce the risk of leptospirosis after exposure to contaminated floodwaters, but access can become uneven across the capital region during typhoon season.
The health professionals stressed that outbreaks reveal how climate change and health risks are intertwined. Dr San Pascual pointed to leptospirosis as a case study, noting that it “happens when a combination of [poor] public infrastructure and humidity combine to cause severe flooding.”
Beyond infectious disease, experts warned that the health burden is expanding to include food security and climate anxiety challenges, warned Dr Sinlao.
“Human health is largely affected by climate change, from vector-borne diseases, to floods and livelihood disruptions [especially for the informal sector] causing [food insecurity and] malnutrition, to extreme weather’s rising burden on mental health,” she said. “These are largely shaped and intensified by climate change.”
Dr Sinlao echoes her colleagues in the healthcare profession to urge the government to establish a national climate health framework. She explained that through a standardised framework, the country can integrate health concerns into disaster risk response and adaptation, as well as meet challenges like antibiotic shortages after floods more easily.
Experts also questioned whether the Philippines’ heavy investment in flood control infrastructure is delivering real protection.
Dr Alfredo Mahar Francisco Lagmay, executive director of the University of the Philippines Resilience Institute (UPRI), cited that the government spent at least P157 billion (US$2.76 billion) on disaster prevention and mitigation in 2021 alone and nearly P78 billion (US$1.37 billion) in 2022, but much of it went on flood control projects that failed to effectively manage extreme inundation.
Dr Mahar Lagmay, executive director of Project NOAH (Nationwide Operational Assessment of Hazards), a government disaster risk reduction and management programme, proposed reallocating funds towards community planning, health system resilience and the integration of scientific data into city development.
The Philippines has allocated a record US$17 billion for climate initiatives this year, with flood control infrastructure as the single largest line item. President Ferdinand Marcos, Jr has since ordered a review of these projects following concerns over corruption and inefficiency.
Between July 2022 and May 2025, the Marcos administration funnelled some P545 billion (US$9.2 billion) into 9,855 flood control projects nationwide. Finance secretary Ralph Recto, during a hearing on Tuesday, said that up to 70 per cent of these government funds may have been lost to corruption and substandard construction work.
The Philippine House of Representatives has launched an investigation into the contractors of the allegedly anomalous flood control projects.
For health experts, the lesson from Quezon City is that fragmented and reactive measures are no longer sufficient. They called for medical education on climate impacts to be strengthened, empowering barangay health workers and placing public health at the centre of adaptation strategies. “Medical professionals… should now be at the forefront of doing advocacy, educating the public and even engaging our policy makers,” said Dr San Pascual.
Without systemic reform, they warned, the cycle of floods and post-disaster disease outbreaks will only worsen. “Years of [infrastructure] development can become meaningless with just one day of disaster,” Lagmay said. “Economic growth is hampered by adverse impacts, and that’s the reason why [these widescale] disasters happen, because we fail to anticipate these bigger extreme weather events.”
