The first “edible” cholera vaccine was created based on GMO rice

How does cholera become infected?

The pathogen usually enters the body through food or water that has been contaminated - these are the main routes of transmission of cholera. Most often, the spread of this disease is associated with an insufficient level of sanitary and epidemiological standards, as well as with the fact that people themselves do not observe basic hygiene rules and eat untested foods and drink dirty water. Infections are mainly typical for countries in which outbreaks of the disease constantly flare up. These include:

• Yemen;
• Iraq;
• Iran;
• India;
• Nigeria;
• Uganda;
• Mexico;
• Tanzania;
• Brazil.

Moreover, we are usually talking about disadvantaged, poorly equipped areas, in which the population has insufficient ideas about hygiene. Cholera is also recorded in the CIS countries, but quite rarely and not in such volumes.

How long does immunity last after Covid?

How long does immunity last after suffering from Covid? A sufficient amount of protective antibodies persists for approximately six months. After five to seven months, unvaccinated people can become infected again.

Immunity after the disease “Covid” appears in people who have been ill not only in a severe form. Previously, it was believed that those who easily suffered the disease did not develop immunity. According to more detailed additional studies, immunity after COVID-19 is formed in all those who have recovered from the disease, regardless of the form of the disease.

Immunity after COVID-19 Sergey Lantyukhov/NEWS.ru

Investigating the question of what kind of immunity after coronavirus, scientists previously discovered that after an illness that the patient suffered in a mild form, there is a low level of antibodies. However, it was later revealed that this indicator is due to the neutralization of antibodies immediately after the disease, but their number gradually increases and remains the same as in those who suffered a severe illness.

This is explained by the fact that the antibodies of the first wave of immune cells in any typical infection have a short lifespan. But then stronger cells enter the process of protecting the body, which produce antibodies for a long time. In addition, the level of protection of each organism is influenced by the general condition, chronic diseases and age.

Immunity after vaccination against coronavirus is formed according to the same principle, so people with initially weak immunity will have weaker protection against infection than healthy patients with a strong body.

Symptoms of the disease

Symptoms of cholera are varied and include the following:

• elevated temperature (37-38), which may, on the contrary, decrease with the development of the disease (to 34-35 degrees);
• chills4
• profuse and watery diarrhea. The color of the stool varies: it can be yellow-green or brown;
• vomit. Often it occurs without urge, suddenly;
• rumbling in the stomach, flatulence, mild pain;
• feeling that the stomach is full of a lot of fluid;
• feeling of dryness. Lips become dry, you are constantly thirsty, and you experience serious weakness. In some cases, lips may turn blue;
• decreased blood pressure, which is associated with dehydration;
• headaches - and the pain itself is localized in the frontal part.

It is important to understand that the problem is not limited to these symptoms of cholera. If the patient is not provided with timely assistance, he risks complications - and with them the situation is much worse.

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Taming Rabies

A graduate of the Paris Ecole Normale and a chemist by training, Louis Pasteur became interested in the nature of fermentation and decay and soon established the role of microorganisms in these natural processes. This, as well as the development of practical recommendations for heating nutrient fluids to preserve them (later called pasteurization), determined Pasteur's lifelong interests in the study of microorganisms and the discovery of new ways to combat disease. Pasteur proposed vaccines against anthrax, chicken cholera and swine rubella, and developed recommendations for combating silkworm diseases. By this time, outstanding researchers Emile Roux, Charles Chambernard, Louis Duclos and others were working in Pasteur’s laboratory. Together with them, he took up the problem of rabies. The decision to work specifically on rabies was partly explained by the previous specialization of Pasteur’s laboratory on animal diseases and the successes achieved in this: he chose a disease that is dangerous for people, but which primarily affects animals.

The methods by which Louis Pasteur and his assistants tried to find means of preventing rabies would now probably cause confusion and serious concern among many scientists. While studying anthrax and chicken cholera, Pasteur actually adhered to his own method of developing a vaccine, which involved obtaining a culture of bacilli of reduced and stable virulence. This was achieved by experiments with isolating and isolating bacilli of certain diseases and growing them in certain environments (for example, with reduced or increased access to oxygen) or by exposing the grown crops to some aggressive substance (for example, carbolic acid). As a result, it was determined in what environment it was possible to obtain weakened bacilli from which the vaccine was made.

The methods by which Louis Pasteur and his assistants tried to find means of preventing rabies would now probably cause bewilderment and serious concern among many scientists

However, rabies is caused by a virus, that is, an agent that was technically impossible to identify and isolate at that time. This already directed Pasteur into the field of experiments, which, strictly speaking, contradicted the foundations of the method he had chosen. For a long time, Pasteur and his assistants were methodically infecting various animals with rabies, trying to find a mechanism for weakening the disease (these experiments, as well as the constantly used vivisections, which were widely reported in the press, at one time made Pasteur an anti-hero of the animal rights movement). This was supposed to open the way to the production of a vaccine from nerve tissue preparations (the level of medical knowledge at that time was enough to understand that an invisible pathogen affects the nervous system and brain). Finally, after numerous unsuccessful experiments, laboratory specialists established that the bone marrow preparation of a rabbit that died of rabies loses virulence as it dries in air. And the sequential administration of these drugs of varying degrees of drying protects the animal from further infection with rabies.

It was at this point that Pasteur approached the most dangerous and ethically difficult stage of his research. Until now, all of its vaccines have been intended to prevent veterinary diseases. Now he had to create a remedy that was intended to save people, which means it should be tested on humans. When it became known that Pasteur was experimenting with the treatment of rabies, victims of rabid dog bites who were facing imminent death began to contact the laboratory. For a long time Pasteur could not decide to use an untested remedy with not entirely clear properties. And yet, in 1885, he gave in to the requests of the parents of the Alsatian boy Joseph Meister (Josef Meister), who was severely bitten by a rabid dog. By this time, Pasteur only had confirmed data that dogs who received the rabbit bone marrow vaccine were protected from further infections. However, the scientist apparently had no data on whether a course of such vaccinations helps if the animal has already become infected. Moreover, a number of experimental dogs did not pass the control period of the experiment. Deciding to treat a person with such data in hand, even by the standards of scientific ethics of the 19th century, was a desperate and dubious step. Be that as it may, Pasteur's experiment was a complete success. The maester was healed. It is worth noting that some modern scientists are still not entirely sure whether the dog that bit Meister was really rabid (the conclusion was made only based on the presence of hay and other foreign objects in the dog’s stomach; for an unknown reason, no other tests were taken to confirm the diagnosis). However, all the serious questions about the decisions made in Pasteur’s laboratory do not give reason to deny that he really found a means of protection against rabies. And rabies vaccination using the Pasteur method soon began to be used in France and other countries of the world with obvious success. Pasteur became a national hero of France and soon received at his disposal an institute that was named after him. He had to study the causative agents of diseases and search for means of salvation from them. The Institute attracted ambitious scientists from different countries who, for various reasons, found it difficult to conduct research in their homeland or wanted to be in the leading bacteriological center in the world. Soon Vladimir Khavkin will link his fate with the Pasteur Institute.

Louis Pasteur - French chemist and microbiologist, member of the French Academy

britannica.com

Complications of cholera

It is not enough to know the symptoms and causes of cholera - you need to understand the dangers of this complex disease. Here are just a few points:

• acute renal failure, a disorder of various metabolic processes in the body with an unpredictable result;
• severe drop in blood pressure;
• myocardial infarction;
• cerebrovascular accident with many serious consequences.

One of these complications can lead to the death of the infected person. Timely treatment of cholera can prevent this.

Diagnosis of the disease

When diagnosing cholera, an important point is to find out the places where a person could have contracted this disease - in order to carry out certain sanitary and epidemiological measures and prevent an outbreak of the epidemic.

Next, the doctor interviews the patient to clarify the characteristics of diarrhea and various pains. Additionally, tests are carried out - examination of feces for the presence of a pathogen, as well as examination of blood for the presence of certain antibodies.

Diagnosis of cholera, taking into account a combination of methods, gives an accurate result and allows you to begin effective treatment.

How are patients with cholera treated?

To treat cholera use:

• antibiotics;
• probiotics to restore intestinal microflora;
• water-salt solutions and glucose (intravenous, in case of severe dehydration and exhaustion).

Be careful! Treating cholera at home is impossible and extremely dangerous. The more prolonged the patient’s condition, the higher the risk of complications, including death.

If you have symptoms, you should contact an infectious disease doctor or call an ambulance at home.

After treatment, patients who have suffered from cholera are further monitored by doctors for another year.

Indian voyage of a Stalinist laureate

If the disease was defeated in the Land of the Soviets, then in other countries of the world, especially in Asia and Africa, it continued to do its dirty work. Therefore, Soviet citizens traveling to dangerous regions were required to be vaccinated.

In 1959, 53-year -old graphic artist Alexey Alekseevich Kokorekin , master of propaganda posters, winner of two Stalin Prizes, was preparing for a trip to Africa. As expected, he needed to be vaccinated against smallpox. There are several versions of why the required medical procedures were not carried out: according to one of them, Kokorekin himself asked for this, according to another, something went wrong with the doctors.

Graphic artist Alexey Alekseevich Kokorekin. Frame youtube.com

Be that as it may, the fatal circumstance was that the vaccination mark was given to him.

The trip to Africa did not take place, but a few months later the artist left for India, where at that time smallpox was as widespread as buckwheat in Russia.

Kokorekin’s journey turned out to be eventful. In particular, he attended the cremation of a local Brahmin and even purchased a carpet that was sold among other things of the deceased. For what reason the Indian lost his life, the locals did not say, and the artist himself did not consider it necessary to find out.

Ten days before the new year, 1960, Alexey Alekseevich arrived in Moscow and immediately generously presented his family and friends with souvenirs from India. He attributed the malaise that appeared upon his return to fatigue from travel and a long flight.

Preventive measures

Prevention of cholera is as follows:

• take the cholera vaccine recommended by WHO. In different countries, immunization of the population is carried out centrally and is strictly controlled. However, it contributes to the development of general immunity - for each individual person, the effect of the vaccine weakens over time, so other preventive measures are required;
• avoid those countries and regions where outbreaks of the disease are regularly observed;
• eat only food that has been heat-treated or washed well with soapy water;
• use exclusively clean water from those sources that are intended for this purpose;
• wash your hands regularly;
• store food in suitable conditions - away from places where insects land on it.

It is also recommended to monitor the situation in the region, and if cholera outbreaks are detected nearby, it is necessary to strengthen control over hygiene, food and water quality.

Society and culture

Cholera vaccination by a Guinean nurse using a jet injector in Ziguinchor, Senegal, 1973.
The first cholera vaccines were developed in the late 19th century. They were the first widely used vaccine created in a laboratory.[14] There were several pioneers in vaccine development. In 1884, Spanish physician Jaume Ferran i Cloix developed a live vaccine, which he isolated from cholera patients in Marseille, and used it on more than 30,000 people in Valencia during that year's epidemic. Waldemar Haffkin then developed a vaccine with less serious side effects, testing it on more than 40,000 people in the Calcutta area from 1893 to 1896.[23] Finally, in 1896, Wilhelm Kolle introduced a heat-killed vaccine, which was much easier to prepare than the Haffkine vaccine, and it was widely used in Japan in 1902.[24]

Oral cholera vaccines were first introduced in the 1990s.[8]

The cost of cholera immunization is US$0.10 and US$4 per vaccination.[25]

In 2021, the US Food and Drug Administration (FDA) approved Vaxchora,[13][12][22] a single-dose oral vaccine to prevent cholera in travelers. As of June 2021[Update], Vaxchora was the only FDA-approved vaccine to prevent cholera.[22] The Vaxchora vaccine can cost more than US$250.[26]

Questions and answers

Is Cholera Deadly?

Timely treatment of cholera allows the patient to fully recover. But deaths do occur; as a rule, they are caused by the patients themselves.

Do you only get cholera in poor countries?

No, this disease can occur in any country - the difference is in the number, intensity and regularity of outbreaks. Hygiene should always be maintained.

How dangerous is cholera for children?

In children, cholera usually occurs in a more complex form and involves severe dehydration. They are especially in need of quick help.

Have there been major cholera outbreaks?

Yes, there are as many as seven cholera pandemics in history. The first falls on the years 1816-1824, and the seventh – on the years 1961-1975.

The current danger of cholera: how high is it?

At the moment, the danger is much lower than half a century ago - outbreaks of the disease are rare and relatively small. However, precautions related to your own health will still not hurt.

Clinical guidelines for cholera suggest that those least likely to be at risk are people who practice good hygiene and avoid visiting potentially dangerous places. In the event of a disease, the winner is the one who, at the first symptoms, turns to infectious disease specialists or calls an ambulance. Also, the described symptoms may be related to other infectious diseases - their timely detection can also save the patient’s life.

Cholera - symptoms and treatment

Cholera is an acute infectious diarrheal disease that poses a particular danger to people. It is caused by the bacteria Vibrio cholerae. Penetrating through the mouth, bacteria affect the intestinal mucosa, disrupting the functioning of the digestive tract. In the absence of adequate treatment, the disease can quickly lead to dehydration, seizures and death [8].

Etiology

Taxonomy of the causative agent of cholera:

• domain - bacteria;
• type - proteobacteria;
• class - gamma bacteria;
• order - Vibrionales;
• family - Vibrionaceae;
• genus - Vibrio (vibrios);
• species - Vibrio cholerae (Vibrio cholerae).

There are many varieties of Vibrio cholerae, but only two serogroups - O1 and O139 - are capable of causing cholera outbreaks. Each of them has its own biotypes:

• Vibrio cholera O1 classica - classic biotype;
• Vibrio cholera O1 El Tor - predominates at present;
• Vibrio cholera O139 Bengal - known since 1992, has caused a major cholera epidemic in Bangladesh, India and other neighboring countries.

The causative agents of cholera are short, curved gram-negative bacteria. In their shape they resemble commas. Their size reaches 0.4-0.6 microns in width and 1.5-3 microns in length.

The bacteria are mobile and do not form spores or capsules. When sowing material, their bluish colonies resemble a school of fish. They are facultative anaerobes, as they are able to obtain energy both in conditions of oxygen and without it. They grow well in alkaline nutrient media.

Vibrios cholerae have a species-specific antigen A and a type-specific antigen O. They contain the genetic information of bacteria and cause an immune response in the body.

The pathogenicity factors of Vibrio cholerae include:

• flagella - make bacteria motile;
• mucinase enzyme - thins the intestinal mucous barrier, facilitating access to the surface of its epithelium;
• neuraminidase enzyme - promotes the production of toxins.

The causative agent of cholera produces two types of toxins :

• endotoxin lipopolysaccharide - does not play a significant role in the development of cholera disease, but can potentially provoke an immune response;
• Cholerogen exotoxin - has a toxic effect only on the intestinal mucosa, causing a massive release of electrolytes and fluid from its cells, leading to diarrhea and dehydration.

Bacteria are very sensitive to acids and alcohol. In feces with sufficient humidity and lack of sunlight they live up to 150 days, in cesspools - over 100 days, in soil - up to 60 days, on fruits and butter - up to 30 days. They survive quite well in low temperatures and freezing conditions. When boiled they die instantly, at a temperature of 56 °C - in 30 minutes. Most antibiotics (mainly tetracyclines and fluoroquinolones) contribute to their destruction [1][2][5][6].

Epidemiology

The source of infection is only humans (patient and carrier). It is most contagious in the first week of illness.

The main foci of cholera are in Africa, Southeast Asia and Haiti, but small outbreaks and isolated cases of the disease are reported throughout the world. The average annual number of cases of the disease is about 5 million people, deaths are about 130 thousand [11].

The transmission mechanism is fecal-oral (water, food and household contact). The main mode of transmission is water. The second most important route is the food route: through meat, seafood, milk, vegetables and fruits that have not undergone adequate heat treatment.

A person, being in the same room with other people, cannot directly infect them. Only the patient’s secretions (feces and vomit) are dangerous if they enter the mouth of a healthy person.

The group at increased risk of developing the disease includes people with blood group O, chronic diseases of the gastrointestinal tract and other organs, the absence or reduced amount of hydrochloric acid in the stomach (achlorhydria or hypochlorhydria).

Cholera spreads much more easily than other acute intestinal infections: it sooner leads to massive release of the cholera pathogen in feces and vomit, which do not have an unpleasant odor or color.

Once in bodies of water (including coastal waters), cholera vibrios can persist for a long time and even multiply. This is facilitated by warm, stagnant, slightly brackish water. Also, reproduction and concentration of the pathogen is possible in zooplankton. In general, cholera is a problem in regions where there is no adequate disinfection and purification of drinking water and hygiene rules are not observed.

Susceptibility to the disease is high. Seasonality is usually summer-autumn. In cities, the incidence is higher than in rural areas. Men get sick more often.

The immunity is strong, but it does not protect the body from infection with other types of Vibrio cholerae. Mortality in the modern world is 1-3% [1][3][5][8].