Years have passed since the peak of the outbreak of a disease that emerged in China to spread across the planet and establish itself as a problem, and its epidemiological and social effects continue to have an impact.
It was recently determined that the Covid-19 pandemic significantly increased mortality among pregnant women in Chile and in a very different way than similar events.
“With this new virus, despite being essentially respiratory in the way it infects the host and spreads, there was an increase in deaths from non-respiratory conditions or diseases. In the influenza pandemic, the increase in mortality in women during pregnancy was specifically due to sepsis and respiratory disease,” said epidemiologist Elard Koch, founder of the Melisa Institute, a research center based in San Pedro de la Paz, who led the study published in the prestigious scientific journal PLOS Global Public Health and was developed with contributions from researchers from academic institutions in Chile, Argentina and Peru.
Specifically, he explained, the research revealed that the Covid-19 pandemic did not affect deaths from direct obstetric causes, and it was indirect non-respiratory causes that increased the most.
“Obstetric causes such as hemorrhage, birth complications, puerperal sepsis and abortion did not increase and remained at the low levels achieved more than two decades ago. Respiratory causes also increased, but to a lesser extent. This confirms that this virus is capable of seriously affecting other systems and temporarily increasing maternal deaths and not due to direct obstetric causes,” he warned to highlight the implications of the results and, above all, of the pathogen.
Natural experiment
Dr. Koch explained that the work was carried out using the methodology of a natural population experiment at the peak of the outbreak of Sars-CoV-2, an emerging strain of coronavirus that causes the disease named Covid-19 after its discovery in 2019 in a Chinese city and whose rapid expansion caused a global health alert since the beginning of 2020 and led to a long crisis.
The data was obtained from the Department of Health Statistics and Information (DEIS) of the Ministry of Health, focusing on the 2020-2021 period, considered the hardest stage of the pandemic in Chile.
Two statistical analysis techniques were used for the experiment. On the one hand, time series were applied to evaluate the effect of the pandemic virus on different maternal mortality groups, and the integrated moving average autoregressive model was used to estimate expected mortality rates in its absence.
Thus, data from before and during the pandemic could be compared to predict maternal mortality trends through a natural experiment in which the effects of an event were observed without experimental manipulation. “This allows us to identify with a fair degree of precision whether there was an effect and quantify its magnitude,” said Koch. “These designs are quite robust for evaluating the causality of a new external agent or factor, for example, catastrophic events such as natural disasters or epidemics of emerging viruses, and they are also used to evaluate the effects of public policies,” he noted.
In fact, using the same method, in a previous study the epidemiologist and his team found that the 2009 H1N1 influenza pandemic only caused a temporary increase in maternal deaths due to sepsis and respiratory diseases, published in The Lancet magazine, serving as an evidence base to determine that Covid-19 affected differently and thus is a different challenge.
Local research to meet the needs and improve public health policies
And the study that emerged to address a need should have a direct impact on public health policies.
“When we face an epidemic or outbreak of an emerging pathogen, such as the coronavirus that causes Covid-19, it is essential to identify the most vulnerable populations in order to design targeted risk strategies, whether preventive or containment. And when they are pregnant, women are more susceptible to some viruses,” explained epidemiologist Elard Koch.
She added: “Previously known coronaviruses were of very low risk or virtually harmless in pregnant women, and we had no precedents for the 2009 Sars-CoV-1 epidemic in pregnant women because its spread was very limited and it mainly affected health personnel. The new coronavirus looked much more virulent.”
Focusing strategies means optimally channeling efforts and resources to achieve more powerful results in areas ranging from restrictive measures and quarantines to active screening and vaccination.
From there, Koch stated that “research during and after the pandemic event is gradually clarifying what was done right or wrong,” helping to identify successes to replicate and mistakes to avoid in the future, on which he stated that “it is essential now to investigate the medium and long-term damages of this pandemic and its management, and to redesign proportionate strategies to confront a new emerging pathogen when it appears.”
In this scenario, he highlighted scientific collaboration as key to addressing complex phenomena, which during and after the pandemic has materialized above all in alliance with members of the University of Concepción (UdeC) and Melisa Institute, making their infrastructure available for proteomic and genomic studies.
“For example, with Dr. Estefanía Nova, a specialist in Immunology at the UdeC, we collaborated on recently published studies on the effects and after-effects of severe Covid-19. Collaboration between researchers is essential to move forward and the Biobío Region is an example of this,” he concluded.
