Inadequate preparation in infrastructure in the Philippines exacerbates post-flood increase in diseases, according to experts.

The Philippine House of Representatives has launched an investigation into the contractors of the allegedly anomalous flood control projects, as the country grapples with a surge in vector-borne diseases and the worsening flood crisis.

The Department of Public Works and Highways (DPWH) in the Philippines has come under scrutiny after it was revealed that a significant portion of the invested funds for flood control projects in 2022 were used for ineffective projects. This inefficiency has been highlighted by the extreme flooding incidents, such as the recent deluge in Quezon City that left 36 out of the city's 142 barangays (villages) flooded.

The Department of Health (DOH) reports confirm an increase in vector-borne and zoonotic diseases such as dengue and leptospirosis after floods triggered by typhoons and heavy monsoon rains. Children aged 10 and below were the most affected by dengue infections in Quezon City, with a 155% increase in cases compared to the same period last year. Leptospirosis, now classified as a climate-sensitive disease, has spiked during the country's monsoon seasons, with Quezon City reporting 521 cases as of late August, up 26% year on year, with 74 fatalities.

Other common vector-borne diseases in the Philippines include chikungunya, malaria, and Japanese encephalitis, which are also transmitted primarily by mosquitoes. Beyond infectious diseases, experts warned that the health burden is expanding to include food security and climate anxiety challenges.

Dr Ramon San Pascual, executive director of Healthcare Without Harm Southeast Asia, stated that Filipinos are experiencing the impacts of climate change, not just in property damage but also in the rise of deaths due to vector-borne diseases. He called for medical education on climate impacts to be strengthened, empowering barangay health workers and placing public health at the centre of adaptation strategies.

Dr San Pascual also urged the government to establish a national climate health framework to integrate health concerns into disaster risk response and adaptation. Dr Annabelle Sinlao, assistant professor, Manila Central University College of Medicine, noted a seasonal shortage of preventive medicine during monsoon months, compounding the crisis.

In response to the escalating crisis, the DOH has released advisories heeding Quezon City citizens to take extra precautions against flood-related illnesses. Dr Mahar Lagmay, executive director of Project NOAH, proposed reallocating funds towards community planning, health system resilience, and the integration of scientific data into city development.

The Marcos administration has funnelled some P545 billion (US$9.2 billion) into 9,855 flood control projects nationwide between July 2022 and May 2025. However, up to 70% of these government funds for flood control projects may have been lost to corruption and substandard construction work.

President Ferdinand Marcos, Jr has ordered a review of climate initiatives projects following concerns over corruption and inefficiency. 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.

As the investigation into the flood control projects continues, the Philippine government faces mounting pressure to address the climate crisis and its impact on public health effectively. Climate change is magnifying the spread of infectious diseases in the Philippines, causing a health crisis that urgently requires a comprehensive and coordinated response.

Inadequate preparation in infrastructure in the Philippines exacerbates post-flood increase in diseases, according to experts.