Detection of superbugs in hospitals triples in pandemic

During the Covid-19 pandemic, the spread of superbugs, microorganisms resistant to several antibiotics, in Brazilian hospitals tripled, shows an analysis by Fiocruz’s LAPIH (Hospital Infection Research Laboratory of the Oswaldo Cruz Institute).

The survey was made from samples of bacteria isolated in eight state public health laboratories and sent to Fiocruz for a more detailed analysis. The group belongs to a bacterial resistance monitoring network from Anvisa (National Health Surveillance Agency). There is still no consolidated data for the entire country.

By 2019, just over a thousand antibiotic-resistant bacteria had been isolated. In 2020, the number of positive samples was almost 2,000. And in 2021, between January and October, more than 3,700 samples were confirmed.

The problem of bacteria resistant to even more modern antibiotics, such as carbapenemics, predates the pandemic, but it got much worse during the health crisis. Among the hypotheses are the high volume of very seriously ill patients in hospitals and the increased use of antibiotics. In Europe, even with the reduction in the use of antibiotics, bacterial resistance also increased between 2019 and 2020.

One strategy has been to go back to using older antibiotics such as polymyxin, which, although more toxic, have proven effective in fighting some of these resistant bacteria. It turns out that even they are losing the match.

Last August, a note from Anvisa, based on data from a public laboratory in Paraná, pointed out that, in addition to a 90% increase in resistant microorganisms, 20% of samples from Acinetobacter baumannii, one of the bacteria causing hospital infections, were already resistant to polymyxin.

According to microbiologist and researcher Ana Paula Assef, head of LAPIH, the fact that patients with severe Covid conditions are hospitalized for a long time, intubated and very debilitated, favors the development of secondary infections, which need to be fought with antibiotics.

With the increase in the use of these drugs, the selective pressure on bacteria also grows. “It is a scenario that favors the spread of resistance. This year, we began to see cases of bacteria that were not so resistant and that they have started to have it”, explains Assef.

Although technical notes from Anvisa and the WHO (World Health Organization) reinforce that antibiotics are not indicated in the routine treatment of Covid-19, since the disease is caused by viruses and these drugs act against bacteria, there was an exaggerated prescription of these drugs .

International studies already attest to this. A survey of 38 hospitals in the state of Michigan (USA) shows, for example, that 57% of 1,705 patients hospitalized with Covid received antibiotics. But only 3.5% had a bacterial co-infection confirmed by tests.

“We had patients with very severe respiratory conditions, staying in the ICU for three weeks or more and it was not known if there was a bacterial infection there, so a lot of antibiotics were used. Apart from the antibiotic azithromycin, which, at the beginning of the pandemic, was used for practically everyone the patients. This may have induced resistance to other classes [de antibióticos]”, says infectologist Rosana Richtmann, from Instituto Emílio Ribas.

For her, bacterial resistance is a silent epidemic, which gets worse every year and the pandemic was the last straw to further aggravate the scenario. “We at hospital infection control had to shift our full attention to the pandemic. Everything we did in terms of monitoring and managing antimicrobial use was limited.”

According to intensive care physician Suzana Lobo, president of Amib (Brazilian Intensive Care Medicine Association), the increase in bacterial resistance was noticed by infectologists and intensivists across the country.

In addition to the more serious profile of patients with Covid, she says that the usual infection prevention practices were underestimated and were absent due to the excess of patients in relation to the number of professionals working in hospitals.

“This situation, added to the indiscriminate use of antibiotics, was the ideal scenario for the increase in cases of infection by multiresistant pathogens that soon spread in hospitals.”

For Lobo, the saturation of the health system and open respiratory units without the safety criteria for being ICU beds also had a negative impact on bacterial resistance. “It will be a side effect of this search for more beds that we will have to deal with for a long time and at a high cost.”

Rosana Richtmann recalls that many professionals hired on an emergency basis to work on the front lines of hospitals had no training in infection control. “Everything done in the emergency, you don’t do it well.”

Ana Paula Assef, from Fiocruz, says that learning about the use of antibiotics needs to be improved among health professionals. “Often, doctors despair of seeing extremely critically ill patients and end up using antibiotics they wouldn’t have needed or could have used a more suitable one.”

Infections caused by resistant bacteria are often associated with high mortality. Anvisa’s August technical note highlights an outbreak in an ICU in Maringá, where ten patients hospitalized by Covid-19 were infected with bacteria A. baumanii resistant to carbapenemic antibiotics, seven died.

Another concern of health authorities has been the combination of resistance mechanisms of some bacteria. In September, Anvisa released an alert on the registration of cases, in Paraná and Santa Catarina, of bacteria P. aeruginosa capable of simultaneously producing the KPC and NDM carbapenemase enzymes, which destroy carbapenem antibiotics.

According to Ana Paula Assef, the presence of these two enzymes makes the use of this new antimicrobial that has been used in Brazilian hospitals to fight KPC-producing bacteria unfeasible.

“Antibiotic is good for one, but not for the other. And the bacteria has both. It’s another fact for us to take into account and be very careful in the use of these new antibiotics.”

In August 2020, the first case of KPC and NDM genes was detected in the same strain of P. aeruginosa. In 2021, 13 patients infected with P. aeruginosa multirresistente.

The indiscriminate use of antibiotics by the population during the pandemic may also have contributed to the increase in bacterial resistance, according to Assef. “Antibiotics only act against bacteria and have no effect against viruses or any other microorganism. You can’t take antibiotics if you know someone or a family member.”

The researcher created the webseries “Confessions of a bacterium” with the aim of making the concepts of bacterial resistance more accessible to children and the lay public in general. The material is available on the Ministry of Health’s YouTube channel.