Fast diagnosis and good sanitation are our best weapons in the uneven fight against a rapid outbreak of disease.
Amoy Gardens is a cluster of 19 tower blocks in Hong Kong, home to no fewer than 19,000 people – enough to populate several rural villages. In 2003, it became the dramatic focus of the world’s attention when 321 residents were diagnosed with severe acute respiratory syndrome, or SARS.
The rapid accumulation of cases, particularly in block E, caused panic. Police and medical staff in protective suits were stationed at the entrance to prevent anybody leaving or entering. The entire block was quarantined.
The outbreak was a conclusive riposte to anyone who still believed that infectious diseases were history, or that they were restricted to impoverished or conflict-torn countries. And it showed how cities can be terrifying incubators.
From bubonic plague in the Middle Ages to bird flu or SARS in the 21st century, infectious diseases have spread horrifyingly fast in cities, where people live in close proximity and are sometimes crowded together. For all that face masks have become common apparel in Asia, city dwellers simply cannot guard their own health independently of their neighbours.
On the contrary, cities need careful planning for health. While infectious and contagious diseases are the most obvious hazard, it is now recognised that the urban environment also has a major part to play in chronic illness.
Heart disease, stroke, diabetes and cancer rates are rising, fuelled by unhealthy lifestyles; fast-food restaurants proliferate in our cities; convenience or fear of busy roads stops us cycling or walking; and there is little green space for active leisure or children’s play.
Keeping It Clean
The Amoy Gardens outbreak also pointed to another factor that even rich cities find hard to master: sanitation.
The official investigation found that the breeding ground for the SARS coronavirus in the Amoy blocks was the toilet system. Each block had eight vertical soil stacks to take waste from toilets, basins and baths, but too little water was passing through to flush it all away. Contaminated water droplets were blown back in by the bathroom air-extractor fans.
Sanitation is a huge issue for cities in low- and middle-income countries, and the Amoy Gardens experience shows just how important and difficult it can be, even in the rich world.
Dr Arpana Verma, director of the Manchester Urban Collaboration On Health, and a World Health Organisation (WHO) expert, says that because monitoring and surveillance of infection is so good in the UK, many British people feel as though we already have a fundamental human right to clean water and sanitation – which indeed is something the WHO’s next set of millennium development goals may set out.
“Even though we have a high population density in the cities, we have the infrastructure in place to monitor and prevent and control the outbreaks that happen elsewhere and we used to see,” she says. Key to this is good hospitals and labs to test the contacts of people who fall ill.
In the slums and shanty towns that have mushroomed around every major city in the developing world, it is a different story. Half of Mumbai’s 11.2 million people live in slums. Most must use public toilets or defecate in the open.
Because the city’s slum dwellers have little space, no money and no right to the land they live on, there is no chance of a conventional sewage system being built – certainly nothing to match the one in the richer part of Mumbai that was constructed by the British in the 1860s.
Instead, the World Bank is funding a huge toilet-block building project, which aims to provide one toilet for every 50 people. The toilet blocks are administered by the community, but families pay a charge for using them – and such is the poverty that some still cannot afford it and defecate in the open.
Persuading city authorities to put in clean water and sanitation for unregistered slum dwellers is a delicate task, says Dr Verma. “Some of the slum housing is phenomenal: three or four floors made out of the flimsiest of materials, with an open toilet that’s shared, which is close to the drinking water and where they clean their clothes. Just a few metres away is a huge tower block. There is the juxtaposition of the incredibly poor with the incredibly rich in cities,” she says.
Arguing that infection could spread from slum to apartment block is dangerous, however: authorities sometimes simply decide to clear the slum, rather than upgrade it.
Britain suffers the same health gap between rich and poor, Dr Verma says. It is the homeless and the vulnerable of British cities who, just like the slum dwellers of Mumbai, suffer most frequently from tuberculosis.
But cities also have health advantages over rural areas. They tend to be richer places, and there is better access to healthcare, even for those who are poor. Children have a greater chance of being vaccinated. A city health commission set up by the Lancet medical journal and University College London reported in 2012 that city dwellers are healthier than rural residents.
But the vast inequalities and their impact on people’s health will not just sort themselves out, the report emphasised. Cities need to be designed and expanded with the health of their citizens in mind. This is, after all, in the interests of the entire planet. SARS did not stay in Hong Kong, any more than it had originated there. It was first seen in mainland China, and travelled from one major city to another and another.
Cities are now linked not by mule paths, but by fast aircraft used by millions of people. As far as viral infections go, it is almost as if we all live in the same city now.
At the time of the SARS outbreak, Dr David Heymann was executive director of the WHO communicable diseases cluster that dealt with the crisis. Now head and senior fellow of the centre on global health security at Chatham House and a professor at the London School Of Hygiene And Tropical Medicine, he says cities are particularly vulnerable to infectious diseases, not just because of their population density, but also because they have major airports. SARS spread from China around the world because people travelled from one city to another.
Ironically, however, the real key to the spread of such infections is the people trying to save the lives of those who suddenly fall sick. SARS in China and Ebola in Kikwit in the Democratic Republic of Congo in 1995 were both spread by unfortunate hospital workers, who were infected before they realised what they were dealing with.
The best protection for a city, Dr Heymann says, has nothing to do with airport screening or special vehicles or technical equipment – the best protection is to ensure good hospital practices. “If health workers get infected, they are a conduit out. What is important is what is done in the hospital.”
In cities with high standards of care and expertise, like London, the policy is to take no risks. “You isolate anything you don’t know. There is no excuse,” he says. If there is a vaccine, as there was with swine flu in 2009, then health workers are the first priority – they must have it as quickly as possible to protect themselves and those they treat.
Because you can’t usually know who is infected until people fall ill and need treatment, the next step is to hospitalise anyone with symptoms – or ask them to stay home and keep away from everybody, which was the case with swine flu, when all infected people were asked to stay home and avoid the GP for fear of infecting others. A phone line was set up to get the antiviral drugs and people were asked to send a friend to the pharmacy rather than leave the house.
SARS may not have made it to London, but the similar virus MERS (Middle East respiratory syndrome) did, since it was identified in 2012 – a virus which scientists now claim may be linked to camels. Those who fell ill were isolated in hospital and treated with the utmost care and caution; all their contacts were traced and tested. There was no question of quarantine, and no need – lab tests can quickly establish whether anybody has the virus.
SARS faded as quickly as it began. By the end of the epidemic in the summer of 2003, 8,096 people had been infected and 774 had died. In Hong Kong, 1,755 were infected and 299 died. Amoy Gardens suffered disproportionately, with 329 sick residents and 42 deaths.
After 10 days in quarantine, the residents of block E were evacuated to three government holiday camps while their flats were disinfected – though the stigma was harder to wash away. While the actions of authorities may have saved lives, the name of Amoy Gardens is now synonymous with one of the worst viral outbreaks of recent times – and proof, if we needed it, that excellent healthcare and proper surveillance are vital in protecting cities even as they become more interconnected and vulnerable than ever before. – Guardian News & Media