Active epidemics in 2022: how to counter outbreaks?

Half a century ago it was predicted that infectious diseases they would stop being a problem thanks to vaccines and antibiotics. But the reality was very different.

To begin with, in 1981 the like, which has so far claimed more than 50 million lives. Even today, 1.5 million people around the world are infected with HIV every year.

More recently we have the pandemic of COVID-19which erupted in late 2019 and from which we are slowly recovering in the West, largely thanks to vaccines.

By contrast, in China, where a “zero covid” policy was enforced until recently, the current upsurge in cases is reminiscent Already seen what we live in Europe, with the collapse of hospitals and a high number of deaths. Worldwide, to date, 650 million people have been confirmed to be infected with SARS-CoV-2 and more than 6.5 million deaths from covid-19. Moreover, the consequences of the persistent or prolonged covid call have yet to be determined

Increased respiratory infections

In addition to these viral pandemics, there were outbreaks of at least six other human infections by the end of 2022.

Autumn-winter has arrived in the northern hemisphere with major outbreaks of respiratory infections due to complaint yes respiratory syncytial virus (RSV). The two years of masks and social isolation to cope with covid-19 have favored the current resurgence of respiratory virus infections.

We have vaccines and antivirals (oseltamivir) against flu virus but not against RSV. The elderly and the immunocompromised are the most vulnerable populations. RSV also affects young children, causing pictures of bronchiolitis that can cause death.

Epidemics caused by viruses of African origin

The outbreak of monkeypox (monkeypox or ‘mpox’, according to the WHO) started in Europe in May 2022. It has spread to more than one hundred countries and 82,000 cases have been confirmed, including 60 deaths. In Spain, 5,000 cases have been confirmed, almost all among men who have sex with men with high promiscuity.

Meanwhile, in Uganda a new outbreak of ebola. It is produced from the Sudan variant, against which there are no vaccines. have been confirmed more than 150 cases and 55 deaths, ten of them among healthcare personnel caring for patients. Schools have been closed and isolation areas have been created in hospitals. The last major Ebola outbreak was in West Africa in 2016 and 2017, with more than 28,000 infected and 11,300 dead.

Outbreaks due to contaminated water or food

In Haiti there is a new outbreak of anger since the beginning of October. To date, more than 10,000 suspected cases have been reported and there have been more than one hundred deaths, many of them in children under 14 years of age. The last major cholera epidemic in Haiti occurred in 2010, after the earthquake that hit the island. There have been more than 800,000 cases and 10,000 deaths. Poor hygienic conditions, malnutrition and poor sanitary infrastructures have favored the resurgence of the current epidemic.

In early 2022, two cases of virus paralysis polio in Jerusalem (February) and in New York (June). Polio was a terrible and common infectious disease until half a century ago. It is produced by an RNA virus which is transmitted mainly by the fecal-oral route, i.e. by contaminated water. Although many cases are asymptomatic, some patients develop neurological damage, with neuronal destruction in the spinal cord. Flaccid paralysis of the lower limbs occurs irreversibly in one out of every 200 infected. The more severe forms, with encephalitis, can be fatal.

After World War II, the vaccine injected with inactivated viruses (Salk’s vaccine) and, a decade later, the oral vaccine with attenuated viruses (Sabin’s vaccine) succeeded in eliminating the infection in much of the world. However, it is still endemic in Afghanistan and Pakistan where vaccination coverage is insufficient. Wars and the covid-19 pandemic have worsened access to vaccines in other Third World countries, such as Yemen, where outbreaks have recently been reported.

In Western countries, about 6% of children under 6 are not vaccinated and are susceptible to infections. Since the beginning of the year, the wastewater study in London, New York and Jerusalem has reported the presence of the polio virus. In all cases it is the attenuated variant used in the oral vaccine (Sabin). The health authorities are committed booster vaccination campaigns for all children aged 1 to 9 years.

Although the oral polio vaccine (Sabin) is more effective than the inactivated virus, it can occasionally cause disease. For this reason, the inactivated virus injected vaccine (Salk) has again been recommended and is currently the most widely used. Of course, although it prevents the development of the disease, it does not block the infection and transmission of the virus.

The WHO approved two years ago a new formulation of the oral vaccine, with a new attenuated virus that incorporates a hypermutagenesis system, which eliminates the risk of reversion to virulent forms. More than 100 million people around the world have already received it and massive administration is expected in the event of a health emergency.

Prevention of new epidemic outbreaks

The fight against infectious diseases has three fundamental pillars. The first is hygiene and prevention of exposure risk. The second are vaccines, which block the infection (by sterilizing) or protect against severe forms. The third weapon against viral infections are antiviral drugs.

In a globalized world, with significant migratory flows, it would be convenient to focus on three interventions:

1. Updated health surveillance programs (WHO, CDC, eCDC, etc.).

2. Ensure high vaccination rates, to avoid the resurgence of outbreaks of viral infections that we thought were under control.

3. Have sufficient reserves of antivirals for immediate use if needed.