Philippines: Tropical Storm Ketsana and Typhoon Parma - Public health risk assessment and interventions



The Philippines is an archipelago located in the western Pacific; the capital and main port of entry is Manila.

The country comprises more than 7 000 islands with a total land area of approximately 300 000 square kilometres. There are three main groups of islands - Luzon in the north, Visayas in the central zone and Mindanao in the South. The country generally has a tropical climate with a wet season from June to November, cooler and dry from December to February, and hot and dry from March to May.

In 2007 the population of the Philippines was 88 million. The annual per capita income is USD 3 430 with a ranking of 102/179 on the UNDP Human Development Index 2007. In 2005, 23% of the population existed on less than USD1.25 per day.

On 26 September 2009, Tropical Storm Ketsana (known locally as Ondoy) hit Luzon island, including Manila, with wind gusts of up to 120 kph. The storm brought torrential rain (estimated 45 cm in 24 hours) which flooded villages and roads and forced thousands of families to seek shelter in evacuation centers. Six metre-high flood waters were reported in parts of Manila. The Cordillera Autonomous Region (CAR) and 25 provinces in Luzon were affected by flooding, with many landslides reported. Thousands of families were displaced and housed in evacuation sites in the heavily affected regions of Metro Manila, Central Luzon and CALABARZON region.

On 3 October, a second event, Typhoon Parma, made landfall north of Manila and compounded the situation. This storm displaced over 35 000 additional people to 188 evacuation centres.

As of 6 October, the National Disaster Coordinating Council (NDCC) reported that over 3 million people had been affected with more than 350 000 located in over 500 evacuation shelters. Over 290 deaths were reported.

The President of the Philippines has declared a state of national calamity and announced that the priorities of its relief operations are to implement and execute medical assistance and relief. Health issues are of major concern in districts affected by flooding.

According to estimates from the Department of Health (DoH), health facilities have sustained extensive damage ranging from submerged ground floors to damage and destruction of medical supplies and equipment, records, and office equipment. DoH reports the majority of hospital operations have now resumed and hospitals have been instructed to provide free service to victims. In addition, the capacity of the surveillance system to detect and respond to epidemics has been further weakened.

An initial rapid needs assessment conducted by the Government with the support of humanitarian partners identified priorities by region. Initial reports prioritized water, sanitation and hygiene issues, as well as emergency medicines and both food and non-food items for the displaced populations.

Given the structural damage to water facilities caused by the flooding, there is a high risk of waterborne diseases among the displaced populations. In addition, extensive damage to infrastructure and distribution systems, as well as to power supplies, render the safe preparation of food virtually impossible, posing an additional risk of foodborne diseases. Water purification units, hygiene kits, essential medicines, and rehydration fluids are urgently needed and have been requested by the Government.

Although noncommunicable diseases have recently replaced communicable diseases as the major causes of morbidity and mortality in the Philippines, in the wake of the flooding and mass population displacement the control of communicable diseases has now become an urgent priority.

Guidance for donors on donations of drugs and medical supplies has been developed by WHO in consultation with over 100 humanitarian organizations and experts (see Sections 2.6, ix, and 4, Guidelines for Drug Donations). These guidelines will help to ensure that the donations are used to maximum effect for the affected population in the Philippines and will help to prevent stockpiling of unwanted medicines and medical supplies.

Factors increasing risks to health

1. Interruption of safe water, sanitation and cooking facilities due to disruption of electricity and fuel supplies. The populations displaced are at immediate and high risk of outbreaks of water/sanitation/hygiene-related and foodborne diseases such as cholera, typhoid fever, shigellosis due to Shigella dysenteriae type 1 (Sd1), and hepatitis A and E.

2. Population displacement with overcrowding. Populations in the affected areas and relief centres have a potentially higher risk of acquiring acute respiratory infections (ARI) associated with crowding. Increased risk of measles and meningitis is also associated with overcrowding.

3. Increased exposure to disease vectors. Displacement of populations can result in increased exposure to disease-carrying vectors, increasing the risk of malaria and dengue as well as other less commonly reported illnesses such as Japanese encephalitis, hantavirus and chikungunya. Flooding may initially flush out mosquito breeding, which can restart when the waters recede. The lag time is usually around 6-8 weeks before the onset of increased malaria or dengue transmission.

4. Malnutrition and communicable diseases. The combination of malnutrition and communicable diseases creates the potential for a significant public health problem, particularly in infants and children. Malnutrition compromises natural immunity, leading to more frequent, severe and prolonged episodes of infections. Severe malnutrition often masks symptoms and signs of communicable diseases, making prompt clinical diagnosis and early treatment more difficult.

5. Disruption of critical services is of immediate concern, including the damage to infrastructure and the disruption of the health, social and security networks caused by flooding. This can prevent access both to the usual services as well as to the emergency medical, surgical and obstetric services put in place in response to this emergency.