BANGALORE - When Robin Thomas, 34, and his wife discovered that they were Covid-19 positive, their first anxiety was about being separated from their four-year-old daughter, Rianna, who had tested negative.

The couple in the southern state of Kerala were already isolated at a government hospital on March 10 when they got their test results. Although they only had mild symptoms - a wet cough and sore throat - the couple dreaded the worst.

"We didn't know much about coronavirus then. I thought we were going to die. I kept thinking, who will raise my daughter?" said Mr Thomas.

To his surprise, the health officials allowed their daughter to stay with them, under strict instructions.

"The doctors and nurses explained to our baby that she can't hug and kiss Mama-Papa - she cried at first, but soon, she was saving up kisses for when we would recover," he said.

Outside, few empathised. Friends ostracised the family, newspapers accused them of having hidden their travel details, and social media exploded with fake news about the places they had infected. The empathetic voices all belonged to doctors, nurses, and health officials.

"Every time I was depressed, there was a sane and kind voice from the government side, keeping me positive. Thank God I was in Kerala," Mr Thomas added.

Many residents in the small, urbanised and Communist-run southern Indian state of Kerala echo this feeling of security.

The tourist haven with backwaters and coconut groves was the first to report confirmed cases of Covid-19 in India: three returning medical students from Wuhan, China. Pathanamthitta district, where some of Mr Thomas' contacts were treated, was India's first Covid-19 hotspot.

And yet, a month into the coronavirus crisis, as India logs over 10,000 Covid-19 cases and about 400 deaths, and extends its nationwide lockdown, Kerala has few new cases, and the country's highest recovery rate of about 55 per cent. Three people have died of Covid-19 in the state since January 28, when the first cases emerged.

Using what Kerala's health minister KK Shailaja calls "a fusion of stringent and humane strategies," the state has flattened the curve, or slowed the rate of infection.

"But we can't say it is the end. We are still paying attention," said Ms Shailaja, in English inflected with her mother tongue, Malayalam.

On Monday, when there were no new cases and 36 recovering patients in the state, an Indian television news anchor praised the minister for her "victory". Unusually for a politician, the minister played it down. "It is not time to celebrate. Anything can change anytime," she said.

Kerala's vigilance about epidemics is thanks to the state's mixed experience with the much deadlier Nipah virus in 2018, which killed 16 of 18 people diagnosed with the disease, including a nurse. After initial mistakes, Kerala established its own surveillance and treatment protocol to contain Nipah's spread. The World Health Organisation has commended the strong emergency preparedness.

Ms Shailaja said she first encountered the coronavirus in January, when she happened to read a news item about "a new SARS-like virus in Wuhan".

"The virus had not gone even to other countries then, but I was sure it would come to Kerala. I knew we had Malayali medical students in Wuhan - some graduates had approached me for internships some years ago. They would bring the virus," said Ms Shailaja.

Since Nipah, the state health department has had regular mock drills for epidemics and training for contact tracing.

So when the Wuhan students came home on Jan 27, they were taken straight to isolation. Three tested positive, but did not spread it.

The capacity to deal with a health crisis as massive as the Covid-19 pandemic, however, has taken longer to build. Decades of investment in decentralised public health systems, public education and women's empowerment have nudged Kerala's social and health indicators up to Scandinavian levels.

Kerala has the highest life expectancy and lowest infant mortality of any Indian state. It has more than twice as many hospital beds for every thousand people as all of India.

But the state's massive migrant inflow - 2.5 million workers from other states, and over 1.6 million expatriates in the Middle East due to return - makes it vulnerable to a highly itinerant virus. In fact, 44 out of 63 Covid-19 cases reported between March 22 and March 24 in Kerala were returnees from Dubai.

Kerala also has a large elderly population. About 14 per cent of the state's population, that is over 4.8 million people, are over 60; Covid-19 tends to be most severe for elderly people.

For the coronavirus, which has a low fatality rate but infects rapidly, Kerala tweaked its epidemic protocol to widen surveillance and contact tracing. It started a public-private campaign called Break The Chain, about hand-washing and physical distancing.

On March 7, when an elderly man went to a hospital with symptoms of Covid-19, officials realised he had been infected by Mr Thomas's family, some of whom had travelled from Italy.

Within hours, he and his family were isolated and interviewed about their movements. Teams of doctors and paramedics fanned out to the district to identify people they might have interacted with.

With interviews, mobile phone tower locations and a Google maps timeline, the district administration formed "a spatio-temporal map" - a flowchart of the family's movements.

"We traced 1,254 contacts of this family in four days, and quarantined all of them," said Mr PB Nooh, district collector of Pathanamthitta, which became India's first hotspot.

He set up a call centre with over 1,000 volunteers. They call those in quarantine every day, filling a questionnaire with details about their medical needs, grocery requirements, and symptoms. Almost 90 psychological counsellors address fears, depression or restlessness.

Kerala imposed a 21-day quarantine period, longer than the WHO's suggested 14 days. By mid-March, travellers from the US, Italy and Spain, and migrants from other states were also being screened.

As more people entered the state, the number of positives swelled. The Pathanamthitta surveillance model was expanded state-wide.

By the time India went into a nationwide lockdown on March 24, Kerala had over 100 cases. But it also had call centres, field surveillance teams, and a three-tier Covid-care hospital system.

The state was aggressively testing high-risk people with links to global and national hotspots, interstate travellers and migrants, even as criticism mounted about India's low overall testing rate. As of Sunday, India had conducted 161 Covid tests per million, while Kerala has conducted 401 per million.

Meanwhile, women's self-help groups, unions, preschool teachers, village officers and sanitation workers run community kitchens and enforce quarantine rules in every neighbourhood.

Many state leaders are now looking to Kerala for inspiration and advice.

The health minister's solution is "socialist planning," with open-minded consultation among opposition parties, health experts, non-profits, unions, private hospitals, and the film industry. "This has become a people's campaign now," said Ms Shailaja.

Her slogan to fight epidemics: "Hope for the best, and prepare for the worst."

Kerala is now bracing for "a second wave," as Malayalis begin to return from the Middle East. After dropping to near zero for two days, the state saw eight new cases on Tuesday - five are foreign returnees from Dubai. Mr Nooh said they would now screen foreign returnees more closely and ask all elders to stay home: "This is an extraordinary situation that requires extraordinary attention. No one is sleeping yet."