GENERICO.ruMedicineInternal enemy. How does a meningococcal outbreak occur?

Internal enemy. How does a meningococcal outbreak occur?

MOSCOW, July 7, Tatyana Pichugina. Eight people were hospitalized in Yekaterinburg with signs of meningococcal infection, two died. And this is not the first outbreak. What is happening and what is the reason – understood.

Sporadic outbreaks

According to the telegram channel Baza, the first patient, a 21-year-old girl, was admitted on June 25. She died the next day. Another patient, a 46-year-old man, died on July 1. Both were employees of the distribution center of the online store Ozon.

On Wednesday, July 5, Rospotrebnadzor in the Sverdlovsk region announced a set of sanitary and anti-epidemic measures in order to prevent the outbreak from growing. “In the course of the epidemiological investigation, the boundaries of the foci were determined at the places of residence and work of infected citizens. Contact persons were identified,” the department noted.

Strengthened measures for the disinfection of premises, medical examinations, laboratory examinations of those who contacted. Organized vaccination of company employees, prophylaxis with antibiotics. Inoculated 60 people. According to the academician of the Russian Academy of Sciences Gennady Onishchenko, quoted by the Vzglyad newspaper, the infection occurred from a carrier of the infection, or from an early stage disease. Fatal outcomes, according to the expert, can occur with a late visit to the doctor.
This is not the first time at Ozon. In November 2022, a similar incident occurred at a warehouse in Istra. Then 11 people were hospitalized, seven of them were contacts. The outbreak was extinguished by anti-epidemic measures, including vaccination.
A year ago, in the summer, five children in Lyubertsy near Moscow fell ill, two died. They didn’t cross paths anywhere, it’s unclear how they got infected. infektsiya-1882678162.html” data->

How meningococcal infection occurs

Meningococcal infection is caused by Neisseria meningitidis. It is a Gram-negative round bacterium. Once in the body, it forms a capsule. The causative agent of gonorrhea also belongs to the Neisseria genus.

“Neisseria meningitidis bacteria were discovered more than a hundred years ago, now 13 types of meningococcus are known – 6 of them cause severe infectious diseases,” comments the chief physician of the Hemotest laboratory Caucasus” David Bichenov.
The natural reservoir of Neisseria meningitidis is located in the human nasopharynx, so the main route of transmission is airborne.
“Moreover, in 70-80 percent of cases, infection occurs from a carrier of a bacterium, that is, from a person who does not get sick himself, but can infect others. According to statistics, about 25 percent of adults carry the infection and do not even know about it,” the specialist continues. . Meningococci die quickly in the external environment, at low temperatures and under ultraviolet light. So it's extremely unlikely to “catch” an infection just by walking past a carrier or sick person. The probability of getting infected is much higher with prolonged and close contact, Bichenov emphasizes.
Infection circulates in the population all year round. However, the incidence usually increases from February to April.

Murder Transformation

How a normally harmless bacterium turns into a killer is not entirely clear. Scientists have found that at first the pathogen forms colonies in the upper respiratory tract, which quickly disintegrate, scattering microbes along the epithelium of the pharynx. Meningococci can cross the blood-brain barrier and infect the brain (this is called meningitis). Why this bacterium behaves this way, which serves as a trigger, is not exactly known. -ratio=”0.583475783475783″ data-crop-width=”600″ data-crop-height=”350″ data-source-sid=”istock-2023″ class=”lazyload” width=”1920″ height=”1120″ decoding=”async” />

According to one hypothesis put forward by researchers from Sweden, the transformation of meningococcus is facilitated by signaling molecules in human cells. Experiments have shown that it may be lactic acid, a by-product of the breakdown of glucose. If its concentration in the cells is increased, the process of explosive growth of colonies and rapid dispersion of microbes starts.

Bacteria attach themselves to cells using special structures called pili. This allows them to gather in colonies. French scientists have found that the pilin protein, which makes up the “hooks” of bacteria, is modified upon contact with the pharyngeal mucosa. The hooks loosen and the colony breaks up. So there is a resettlement to other parts of the mucosa. The authors of the paper compare this to cancer metastases.

Where do meningococcal outbreaks occur more often

In November 2020, the World Health Organization again urged the scientific community to pay attention to antibiotic-resistant bacteria, including some strains of the Neisseria genus that have acquired drug resistance. One of them, highly invasive meningococcus CC4821, originated in China and can start epidemics.

Unlike other microbes, representatives of the genus Neisseria mutate very quickly. This is facilitated by a number of features. So, they are able to “steal” genes from other bacteria, which means they change quickly. They do not have the most efficient DNA repair system, which leads to the accumulation of mutations. The growth factor of the Earth's population is also important: the more people become infected with meningococcus, the faster it evolves. Therefore, urgent action is needed, experts warn.

This infection is everywhere, but in some places it is especially common. Large epidemics occur in a group of 26 African countries south of the Sahara and from Senegal to Ethiopia, this region is called the “meningitis belt”. The memo of Rospotrebnadzor for those traveling there says that the risk of infection increases during dry times, when it is very windy and dusty, and cold nights. All this makes the upper respiratory tract vulnerable. The situation is complicated by overcrowding, displacement of a large number of people (for example, pilgrimages).

Who is at risk and measures to prevent meningococcal infection

In Russia, according to Rospotrebnadzor, 6684 cases were confirmed from 2010 to 2021. Strains of serogroups B, A, C predominate, less often W. Since 2016, there has been an increase of ten percent per year. Young people are increasingly becoming infected.
The source can only be a sick person or a carrier of the infection. It is impossible to get infected from domestic or wild animals, since this pathogen lives only in humans. Transmission occurs through close contact or through household items. At risk are pilgrims, military personnel, tourists, athletes, geologists, biologists, infectious disease doctors, as well as those living in boarding schools, hostels, listed in the Center for Hygienic Education of the Population of Rospotrebnadzor.

“Meningococcal infection is a rapid and dangerous disease. The incubation period can last up to 10 days, but most often the first symptoms appear after 1-3 days. The temperature rises sharply to 38-39 degrees, the tonsils and the back wall of the nasopharynx turn red, there is abundant discharge from the nose from mucus and pus.The classic symptom of a meningococcal infection is a severe headache and stiffness, that is, strain, of the muscles of the back and neck.Adults may complain of pain and cramps in the back.And if you ask a sick child to press his chin to his chest, he will not be able to do this due to severe pain in the chest and neck,” describes David Bichenov.
Most of the disease is asymptomatic or as a common ARVI, the diagnosis can only be made in a laboratory study.
“To engage in self-diagnosis and self-treatment is extremely dangerous. — The doctor warns. — Over the past hundred years, medicine has learned to cope with meningococcus with antibiotics, but the disease still causes severe complications – patients fail the kidneys, sepsis develops, and the work of the central nervous system”.
Letality in severe cases reaches 50 percent.

Vaccination is used as a preventive measure, as well as at the risk of an epidemic. The drug is administered once, the vaccine is well tolerated, immunity lasts for ten years. /20221130/meningit-1835429042.html” data->


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