Islamabad, Pakistan – Scientists and public health experts are continuing to conduct research into why some South Asian countries – despite their ramshackle health infrastructure and dense populations – have witnessed lower coronavirus mortality rates compared with many Western countries.
By early May, the world’s richest countries accounted for more than 90 percent of all reported deaths from COVID-19, according to a paper published in The Lancet medical journal. Adding China, Brazil and Iran to that list takes the number up to 96 percent.
By contrast, many densely populated developing countries in South Asia and parts of Africa have fared far better when it comes to the mortality rate from COVID-19, data from Johns Hopkins University (JHU) shows.
In Europe, the observed case fatality ratio (CFR, or the percentage of deaths among confirmed coronavirus patients) has been high, with France reporting a rate of 15.2 percent, the United Kingdom 14.4 percent, Italy 14 percent and Spain 11.9 percent, according to JHU data. In the United States, the CFR is 6 percent, the data shows.
By contrast, in South Asian countries, those rates have been far lower. India has a CFR of 3.3 percent, Pakistan 2.2 percent, Bangladesh 1.5 percent and Sri Lanka 1 percent.
“The rest of the world – historically far more used to being depicted as the reservoir of pestilence and disease that wealthy countries sought to protect themselves from, and the recipient of generous amounts of advice and modest amounts of aid from rich governments and foundations – looks on warily as COVID-19 moves into these regions,” write Richard Cash and Vikram Patel, public health experts at Harvard University, in The Lancet.
Doctors and scientists say there are a number of possible explanations for the discrepancy in how COVID-19 is affecting populations in different parts of the world, whether due to varying demographics, different levels of exposure to similar viruses or even incomplete data on mortality in some countries resulting in faulty conclusions.
In Pakistan, home to 220 million people and rickety health infrastructure that offers just six hospital beds per 10,000 people, the first case of the coronavirus was reported on February 26, a returning traveller from neighbouring Iran.
Since then, the virus has spread rapidly, with at least 42,125 cases reported countrywide as of May 18, making Pakistan the 20th in the world in terms of the total number of cases. It has reported 903 deaths, making it 26th worldwide on that list, with a CFR one-third that of the US, and up to 13 percent lower than some European countries.
Is the data accurate?
The first question researchers have asked when examining the data is whether the number of deaths being reported in Pakistan and other countries is, in fact, accurate.
In neighbouring India, for example, some have questioned whether deaths are being accurately documented, with as many as 78 percent of deaths not being medically certified under normal circumstances.
In Pakistan, too, this is a possibility – although medical experts working with the government in its fight against the pandemic suggest the error rate would be far lower.
“There is such a stigma around the whole business of COVID, that people do not want to bring their patients to the hospitals,” said Dr Seemin Jamali, head of the largest government hospital in Karachi, the country’s most populated city.
The bodies of those confirmed to have been infected with COVID-19 at the time of death are dealt with through strict measures at government hospitals, with officials in full protective kits bathing the body as part of traditional Islamic burial.
“The district [officials] come to receive the dead body, and we pack it in a body bag. There needs to be a better mechanism for transporting the dead, because this is something that people don’t want to [happen],” says Jamali.
“Bathing [the dead body] is a very important ritual for Muslims in Pakistan, so it is not possible that you to completely sideline people and say you will bury [their family members] yourselves.”
Nevertheless, Jamali and other experts agreed that this appeared to result in only a modest decrease in the reporting of deaths – whether COVID-19-related or not.
Dr Faisal Sultan, Pakistani Prime Minister Imran Khan’s focal person on the coronavirus crisis, says the government has put systems in place to ensure that all deaths are being accounted for, including direct coordination with provincial health authorities and community outreach using Pakistan’s extensive network for polio vaccination.
“The health system is so sensitised right now to COVID that in the present situation, the possibility of [large numbers of] underreported deaths is unlikely,” he told Al Jazeera.
Dr Faisal Mahmood, head of infectious diseases at Karachi’s Aga Khan University Hospital, the largest research hospital in the country, concurred, saying results from a preliminary survey at the city’s graveyards had not suggested a rise in deaths as opposed to the previous year.
Al Jazeera also interviewed doctors and officials at major government hospitals in Karachi, the eastern city of Lahore, the capital Islamabad and the southwestern city of Quetta – where a number of coronavirus cases have been reported. None noted any marked increase in patients who were dead on arrival, whether from the coronavirus or other causes.
However, Dr Mahmood cautioned: “It may be that our death rate is not low, but that our epidemic is slow or that we are earlier in our epidemic, and that eventually, we will have the same death rate.”
If the data on the number of deaths is relatively accurate, that leaves several other possible explanations for why Pakistan is seeing so few deaths compared with other countries.
The US, for example, at the same stage in its outbreak (66 days since 100 cases were confirmed) had reported more than 65,000 deaths. Pakistan’s 903 is two orders of magnitude below that number.
Dr Adnan Khan, a public health researcher and infectious disease specialist, says much of the exploration of correlations with coronavirus mortality rates is “conjecture” at this point without the backing of hard facts and comprehensive study, but that the demographics of South Asia’s population, and South Asians’ physiology, may have the answer.
“The younger population hypothesis is more credible [than other theories],” he says, citing Pakistan’s relatively younger demographics as compared with countries where COVID-19 has claimed more lives. “Many of the deaths in developed countries have reportedly happened in elderly people living in nursing homes.”
In the UK, more than 37 percent of the country’s 33,614 coronavirus-related deaths have occurred in elder care homes, according to the UK’s Office of National Statistics. In the US, that number is also about one-third of all coronavirus deaths, according to a report in the New York Times.
By contrast, Pakistan – and South Asia in general – has a far younger population than those countries, with a median age of 22.5.
“This may be one of the reasons, because if you look at the population pyramid, we have fewer elderly people as compared with the US and Europe, and we know those are the folks who are dying more frequently,” said Dr Mahmood.
Varying immune responses
Another factor that has been suggested is differences in the population’s immune characteristics.
“Is it the environment around us? Different environmental factors that have changed our immune system in some way? We have chronic infections like tuberculosis and others [in this part of the world], or it may be because of vaccinations,” says Mahmood. “We don’t know the answer to that particular one.”
Adnan Khan, the public health researcher, believes there could be higher immunity due to exposure to other infections, but that any correlation with vaccine use would have to be borne out by further study.
Pakistani children receive expanded immunization, with vaccinations against nine different diseases being administered in several rounds before the age of 18 months.
Dr Sultan agrees that this could be a factor, but cautioned against jumping to conclusions – as many have hastily concluded that use of the BCG tuberculosis vaccine gives greater resistance to COVID-19.
“People talk about how our exposure to various pathogens or patterns of immunisation change how our immune system is,” he says. “All of these things are possible, but no one has been able to categorically prove it.”
Another possible factor could be the environment in South Asian countries, he said, indicating that regions with higher average temperatures and levels of sunlight and its associated ultraviolet radiation have shown relatively lower death rates so far.
Researchers have, based on the data available so far, downplayed the possibility that the strains of the virus affecting South Asia are different in any meaningful way from those hitting European and other countries where death rates are higher.
“Biologically we know that the coronaviruses do not mutate that much – whenever a virus replicates, there is a bit of mutation built in, but the coronaviruses have error-proofing enzymes, so they tend to mutate less,” said Dr Mahmood. “And these mutations don’t always affect how virulent the virus is […] they are more useful in terms of identifying the strain than affecting its [lethality].”
Whatever the reason, all researchers that Al Jazeera spoke to said it was far too early to say categorically why certain countries were seeing lower levels of deaths from the coronavirus.
“I want to be clear: we don’t know exactly what is going on right now [with the lower deaths],” said Dr Sultan.
Wide prevalence, lower deaths
On the other end of the spectrum from examining deaths, Dr Wajiha Javed, the head of public health and research at Getz Pharmaceuticals in Karachi, has been examining the prevalence of the virus among Pakistanis. Her findings tend to bolster the conclusion that something is causing people in Pakistan – and the region generally – to react differently to the virus.
Pakistan, like many developing countries, is performing limited numbers of tests per day, which are almost exclusively Polymerase Chain Reaction (PCR) swab tests. The country has conducted 387,335 tests since the outbreak began, according to government data. Those tests are being conducted largely only on those who have exhibited symptoms.
Javed, however, found that the prevalence of asymptomatic carriers of the virus in her surveys has been far higher than expected. In results from 4,000 tests carried out on factory and office workers, her data shows that between 7 and 8 percent were testing positive.
“This was in ‘normal’ people, not people who are going to the hospital, who are even sick or have any symptoms whatsoever,” she said. Out of her sample, roughly 90 percent had not exhibited any symptoms at all, she said.
“Our disease is different. We have people who are exhibiting mild symptoms or no symptoms at all. That might show that we have some sort of innate immunity that is protecting us from going into severe or moderate disease,” she added, stressing that those who do experience severe forms of the disease have the same risk of death.
“That doesn’t mean we are not infected, and that we are not infecting others.”
Asad Hashim is Al Jazeera’s digital correspondent in Pakistan. He tweets @AsadHashim.