Filipino residents wait in line to receive relief goods on the outskirts of Pasig, east of Manila, on Oct. 22, 2009
Albert Casis swerves his tricycle taxi to a stop just before the floodwater, lapping over a speed bump in the road. He knows the mud-colored water could be contaminated with a potentially deadly rat-borne disease that is still threatening communities in and around Manila a month after tropical storm Ketsana hit the Philippines' capital. "I saw the warnings on TV," says the lanky 19-year-old, watching pedestrians wade through the knee-high water covering part of a road in the capital's Pasig district, one of the worst flood-hit areas.
Nearly 860 people were killed in flooding and landslides after Ketsana and typhoon Parma tore into Luzon, the country's largest island, in late September and early October. Four weeks later, sections of the city and some surrounding provinces are still underwater, and state-run hospitals have been overwhelmed by an outbreak of leptospirosis, a bacterial disease spread from the urine of infected rats and other animals. (In Sri Lanka, where there was a large outbreak in 2008, leptospirosis is known as "rat fever.") The bacterium is transmitted by the standing floodwater through cuts in the skin and by people swallowing contaminated water. This month's leptospirosis outbreak — the worst by far that doctors here can remember — has swollen the disaster's death toll, claiming 157 victims from mostly poor communities.
National health authorities have been trying to contain the unusually virulent outbreak of the common disease since the first cases appeared around a week after the storm. They are distributing antibiotics to some 1.3 million people living in still-flooded areas in the capital and two nearby provinces. But last week, the country's top epidemologist sent out an "SOS" to the global health authorities. A medical mission from the World Health Organisation's (WHO) Global Outbreak Alert and Response Network was set to arrive in Manila today and Tuesday. WHO officials in Manila said the four-person team will comprise two epidemiologists and an expert each in clinical management and leptospirosis.
Part of its task will be to evaluate the government's response in tackling the disease, and draw up recommendations for future large-scale leptospirosis outbreaks, said Eric Tayag, head of the Department of Health's National Epidemiology Center. "They will also be looking at why there have been such high mortality rates" in the current outbreak, he said. Between 5 and 10% of the cases in this outbreak have been resulted in death — the highest level of mortality for leptospirosis by WHO's measures.
The Philippines' overstretched and underfunded public health system is poorly equipped to deal with large-scale disease outbreaks, even for diseases like leptospirosis that are seasonally common across the archipelago. Several large government hospitals were damaged in the flooding, and have struggled to cope with the influx of patients. A week after Ketsana, much of Pasig General Hospital was under water, including its laboratory. According to reports, staff initially only had dextrose to give flood victims seeking medical attention. In flood-ravaged Marikina, one of 16 cities that make up Metropolitan Manila, only four out of 21 public health facilities were in operation as of Oct. 24. San Lazaro Hospital, the main government hospital specializing in infectious diseases, has treated 451 leptospirosis cases since the storm hit on Sept. 26 — nearly double the number of cases in the span of just a month than is usual for the whole last year. "We expected cases to rise because of the unusually heavy flooding, but we were not prepared for the numbers and we eventually ran out of testing kits," said Eumelia Salva, head of San Lazaro's public health services.
Ketsana dropped more rainfall on greater Manila's 14 million residents in a nine-hour deluge than in an average month of the country's rainy season from July to November. At the height of the storm, 80% of the capital was underwater. The rainfall was exceptional, but the severity of the flooding was intensified by the city's garbage-clogged drainage system, partly from the shanties of informal settlers living along waterways and decades of skewed urban planning.
Authorities quickly issued health warnings about waterborne diseases after the storm. For leptospirosis, people were told to cover cuts and abrasions with waterproof bandages, and thoroughly wash after wading in floodwater. Early symptoms of the disease include fever, rash, vomiting and jaundice; renal failure, hemorrhaging and liver disease are among its life-threatening complications. An average of 680 leptospirosis cases and 40 deaths from the disease are reported every year in the Philippines. And while its incidence is far higher in tropical than temperate regions, global surveillance of the disease is generally poor, said Adam Craig of WHO's Western Pacific regional office in Manila.
The worst of the outbreak, it appears, is over. Since its peak around mid-October, the number of confirmed cases has steadily declined, a likely reflection of its incubation period and the receding floodwater. But with some areas expected to remain underwater for months due to still flood-swollen rivers and waterways, "the potential for more outbreaks is still there," warns Tayag. Last week the Philippine health authorities began distributing the antibiotic doxycycline in flooded communities, a procedure recommended by the WHO. Plans are now being readied for a large-scale spraying of saltwater into still-flooded areas to kill the leptospirosis bacterium, which only lives in freshwater. The timing to ask for help from the global health authorities — as well as other decisions such as the distributing of antibiotics and the saltwater spraying — were "judgment" calls, says Tayag.
But for those living in flooded areas, the specter of swarms of rats on the loose after being flushed from their lairs by storm waters is obviously still alarming. "We told our children not to go in the water and we check them every day for cuts," said Nerio Taculod, a 45 year-old father of five and a member of the security detail of Pasig's mayor. "The people here now know about leptospirosis, but many have no money to buy protective clothing like rubber boots, but we're taking no chances."