IELTS Academic Reading Practice Test 380

Severe acute respiratory syndrome, almost always shortened to SARS, entered the world's headlines in the spring of 2003, when a severe form of pneumonia that did not respond to antibiotics began appearing along the routes of international air travel. The disease had in fact been circulating for several months before that. Cases of an unusual pneumonia had been recorded in Guangdong province in southern China from November 2002, and Chinese health officials knew of them long before any other country did. The interval before the outbreak was reported internationally is one reason it travelled as far as it did.

China notified the World Health Organization of the outbreak in February 2003, reporting several hundred cases and a number of deaths in Guangdong. By then, however, the infection had already left the province. In late February a doctor who had treated patients in Guangdong travelled to Hong Kong and checked into a hotel. He was already unwell, and during his stay he passed the virus to a number of other guests and to a visitor. Those people then flew home, carrying the infection to Vietnam, Singapore and Canada. The doctor himself died in Hong Kong.

The most consequential of those encounters took place in Hanoi, where one of the infected guests was admitted to a hospital. The patient was examined by Carlo Urbani, an Italian epidemiologist working for the World Health Organization, who found the illness unlike anything he had seen before and immediately alerted his employers. His warning helped to prompt the first global response, and the disease also cost him his life: Urbani died of SARS on 29 March 2003. The hospital was closed to new patients, and its staff were isolated and monitored.

On 12 March 2003 the World Health Organization issued a global alert about cases of atypical pneumonia, and three days later it gave the illness its present name and took the unusual step of advising travellers to avoid the worst-affected areas. Laboratories in a dozen countries were linked through a network organised by the organization, so that findings could be shared from one day to the next. The collaboration produced answers with remarkable speed. On 16 April the organization announced that a previously unknown coronavirus, a member of a family named for the crown-like spikes on its surface, was the cause.

Confirming that a newly discovered agent actually causes a disease requires more than finding it in patients. A team of virologists in the Netherlands infected monkeys with the virus and showed that they developed the same illness, which satisfied the classical test of causation. Meanwhile, teams in Canada and the United States had sequenced the full genetic code of the virus by the middle of April. That sequence allowed laboratories to design diagnostic tests within weeks, and it later made possible the rapid identification of related viruses.

SARS spread mainly through respiratory droplets, in the coughs and sneezes of people who were already ill, and through close contact such as touching a contaminated surface and then the face. It was not especially infectious compared with influenza, and most patients passed it to only a few others. A small number of individuals, however, infected dozens of people at once, and these events shaped the epidemic.

In Hong Kong a single housing estate, Amoy Gardens, produced more than 300 cases in a few weeks, and the hotel where the doctor from Guangdong had stayed became the starting point for outbreaks in several countries. Health workers were themselves at risk: a substantial share of those infected had caught the virus from patients.

Because no vaccine existed and no drug reliably worked against the virus, control depended on old-fashioned public health. Patients were isolated in hospital, and those who had been in close contact with them were asked to stay at home for ten days, the longest period in which the illness was then thought to appear. In some cities schools and universities were closed; elsewhere, thermometers were used at airport checkpoints and passengers with a fever were pulled aside. In Beijing, where the authorities had at first concealed the scale of the outbreak, a hospital with a thousand beds was built in seven days on the edge of the city.

The strategy worked, though at a price. On 5 July 2003 the World Health Organization announced that the last chain of human transmission had been broken. Over the eight months of the epidemic, 8,096 probable cases and 774 deaths were reported from 26 countries. The overall death rate was therefore close to one in ten, and it rose steeply with age: very few children died, while among patients over 65 the disease was often fatal. The economic damage was severe as well: tourism and business travel fell sharply across East Asia, even in countries that had no cases at all.

SARS has not disappeared from scientific view. Surveys carried out after the epidemic identified closely related coronaviruses in horseshoe bats, which are now thought to be the natural reservoir of the virus, and in masked palm civets sold in markets in Guangdong, which may have acted as an intermediate host. The virus also escaped from laboratories more than once, in Singapore and Taiwan in 2003 and in Beijing in 2004, causing a few further infections. When a new coronavirus was identified in Wuhan at the end of 2019, it was named SARS-CoV-2 because of its close resemblance to the earlier one.

Contact tracing is one of the oldest tools of public health and one of the least glamorous. When a person is diagnosed with an infectious disease, health workers try to establish two things: whom that person may have infected while they were capable of passing the infection on, and whom they themselves caught it from.

The people identified are then contacted, warned and supported to stay away from others until the danger has passed. The technique was refined for tuberculosis and for sexually transmitted infections long before it was asked to cope with a novel respiratory virus, and it remains labour-intensive. When it works, it leaves almost no trace: a contact who is warned in time and never falls ill does not appear in any record.

The process begins with an interview. A trained tracer asks the patient to go through the period in which they were infectious, day by day, and to name everyone with whom they spent any length of time. This sounds simple and is not. Patients forget. Some cannot name the people they sat beside on a bus or spoke to in a shop. Others are reluctant to mention contacts that reveal something they would rather keep quiet, such as an undeclared job or a relationship they have not admitted to. Stigma is one of the most stubborn obstacles to good tracing, and it is the reason interviews are conducted by people trained to ask without judging.

Once a list exists, each contact must be reached and told what to do. Typically they are asked to monitor themselves for signs of illness, to keep away from other people and to report symptoms at once. For some diseases they are offered treatment or vaccination. The whole sequence only works if it is rapid. A contact who is warned before they become infectious can be isolated at the first sign of illness, and the people they would have infected are never exposed at all. For a disease with a short serial interval, the time between one case and the next in a chain, a tracing system that takes a week is almost worthless.

Tracers distinguish two directions of work. Forward tracing follows the infection onwards, from a known patient to the people that patient may have infected. Backward tracing goes the other way, asking where the patient caught it and which setting or person links them to other cases. Backward tracing becomes especially valuable when many patients have no obvious connection to one another, because it can uncover a single event, such as a dinner, a wedding or a crowded workplace, that explains a large cluster of cases at once. It was used to good effect during outbreaks of Ebola in West Africa, and it was widely recommended during the coronavirus pandemic, when many patients could not say where they had been infected.

Since 2020 the work has been supplemented, and sometimes partly replaced, by smartphones. Bluetooth applications record when two phones come close to each other and store the encounter; if one user later tests positive, the others can be alerted without anyone learning who the patient was. Several countries used a system of this kind built jointly by Apple and Google. The appeal is obvious. An application has no memory to strain, and it can notice a stranger standing next to you in a queue, a person an interviewer could never identify. It also works at a speed no team of interviewers could match.

Proximity is not the same as location, however, and the two kinds of data raise different questions. Location data, from GPS or from the network of cell towers that phones constantly communicate with, record where a device has been, not whom its owner met. During the pandemic some health agencies used aggregated and anonymised mobility data, published as maps rather than as lists of individuals, to see whether people in a region were staying at home. Bluetooth data identify contact but not place; location data identify place but not contact. A team that wants to warn individuals needs the first; a team that wants to understand the shape of an epidemic can often manage with the second.

The evidence on how much these applications actually contributed is thinner than the publicity suggests. Randomised trials are rare, and the observational studies that exist are hard to interpret, because applications were introduced at the same time as other measures, including lockdowns, masks and travel restrictions. Modelling studies, which assume that users behave as instructed and that most of them install the software, tend to be more optimistic than the epidemiological record. What is not in doubt is the operational value of tracing done well, as the Ebola vaccine trials in Guinea showed. The contacts of each new patient were found and vaccinated, a strategy known as ring vaccination, and without a reliable list of contacts there would have been nobody to protect.

Whether tracing succeeds therefore depends less on software than on conditions that have little to do with technology. Teams need enough trained staff, and in some cities during the pandemic tracers were expected to handle dozens of cases each day. People asked to isolate need somewhere to live and money to live on, which means paid sick leave and practical support; a tracer who orders a delivery driver to stay at home for a fortnight without pay is asking for non-compliance. Above all, the public must trust that the information they give will not be used against them. Where tracing has failed, the shortage has usually been of trust rather than of data.

Few measures adopted during the coronavirus pandemic were as widely accepted, or as little examined, as the collection of data from mobile phones. Within weeks of the first lockdowns, several governments had negotiated access to information held by mobile networks, and public health agencies in many countries had launched applications that recorded encounters between devices. The argument that followed was often conducted as though the only question were whether such tools work. It is not. The question that matters is whether a democratic society should allow its health service to know where its citizens have been, and if so, on what terms. Two broad positions have emerged, and neither is unreasonable. Much of the legal basis for these schemes was improvised at speed, with parliaments asked to approve powers they had no time to debate.

The case in favour rests on speed and scale. A human interviewer can reach perhaps a few dozen contacts a day and depends on a patient's memory, which is fallible at the best of times and especially so during illness. A digital system can warn thousands of people within minutes, including strangers whose names the patient never knew. Advocates add that the information can be anonymised, that the alternative to collecting it is not privacy but a longer epidemic, and that in an emergency hesitation costs lives. On this view, a health agency that refuses useful information is making a choice on the public's behalf, and one that the public has never consented to. In the first wave, several agencies found that tracing by interview alone had collapsed under the weight of cases; automation looked like the only way to keep pace.

The case against begins with accuracy. Advocates overstate the accuracy of what is collected. Phone location data are far coarser than they appear on a map: in a city a device may be assigned to a cell tower covering several streets, and in the countryside to one covering many square kilometres, while GPS readings drift, especially indoors. A person wrongly identified as a contact may lose a fortnight's wages for nothing, and a person who is missed may infect others while believing they were safe. Bluetooth is no better, since the strength of a radio signal is a poor guide to distance: walls absorb it and bodies block it. Nor do these systems reach everyone equally. Those without smartphones, often the elderly, the poor and the young, are precisely those least able to protect themselves.

The deeper objection is political. Emergency powers have a habit of outliving the emergency that justified them. Once a database exists, closing it requires a decision that no one has an incentive to take. Databases assembled for one purpose are rarely discarded, and the temptation to use them for another, whether policing, immigration control or the management of welfare, has proved hard to resist. The knowledge that one's movements are being recorded also changes behaviour, discouraging people from attending protests or visiting places they have a right to visit. Consent is a fragile defence when it is requested by a government in the middle of a health crisis, when the alternative appears to be more deaths. A population that says yes under such conditions has not really chosen. Legislatures are slow and emergency regulations are quick, and that imbalance is seldom corrected once the crisis has passed.

None of this means that the data can never be used. It means that the burden of proof lies with those who wish to collect it, and that the conditions must be strict. Collection should be authorised by legislation rather than by ministerial decree, and the purpose should be narrow and written down. The scheme should be limited by law to a fixed duration and should lapse automatically unless it is renewed. A time limit written into the authorising law is worth more than a promise made at a press conference. Independent oversight, public reporting and the right of individuals to know what is held about them are all essential. Where aggregated data, such as counts of devices in a district, can answer the question, individual data should not be gathered at all, and the simpler design should be preferred. Records of tests and vaccinations, which are just as sensitive, deserve the same safeguards.

My own conclusion is therefore neither that location data must never be touched nor that anything is permissible in a crisis. Individual data may be justified in a severe epidemic, but only when the measure is necessary, proportionate, limited in time and accountable to the public it serves. Those who argue that the technology simply should not be used are defending a principle at a cost that others have to count. Those who argue that effectiveness settles the matter are asking us to forget what is at stake. A choice of this kind must be argued for, openly and repeatedly, by the bodies that are supposed to make such decisions, rather than settled quietly by procurement officers and software developers; it cannot simply be assumed. The alternative to a defended scheme is not the absence of any scheme, but one that collapses the moment a mistake becomes public.