IMMUNO-PREVENTABLE DISEASES: SYMPTOMS, CAUSES AND TREATMENTS - MEDICINE - 2025

The preventable diseases are those infectious diseases preventable generating immunity through the application of vaccines. Its application against these diseases encourages the production of antibodies that protect the body specifically against the disease for which it is being vaccinated.

Before the discovery and development of vaccines, infectious diseases caused millions of deaths around the world. Diseases such as polio, smallpox, diphtheria, measles or tetanus, to name a few, wreaked havoc on the world's population.

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Thanks to sanitary measures and mass vaccination plans, some of these diseases have been eradicated or appear in very small and rapidly controlled foci, with very low mortality rates.

Immuno-preventable diseases

There is a fairly broad list of immunopreventable infectious diseases for which vaccines have been developed.

These vaccines, in some cases, can generate permanent immunity when the corresponding boosters are applied. In other cases, they generate seasonal immunity, especially in those diseases generated by constantly mutating microorganisms, which requires the development of new vaccines for each seasonal epidemic outbreak.

Next, there will be a brief description of some infectious diseases with their causes, symptoms, treatment and general vaccination schedule that show the importance of immunoprevention to reduce epidemics and avoid the high mortality rates of some of these diseases.

1- Measles

Measles is a viral disease produced by an RNA virus of the Paramyxoviridae family and of the Morbillivirus genus. The virus is found in the nasopharyngeal secretions, urine, and blood of an infected person. It can stay active for up to 34 hours at room temperature in a room.

It is an eruptive disease, extremely contagious. Although measles is an endemic disease in most of the world, thanks to vaccination, it is currently under control and has been eradicated in many countries.

Signs, symptoms and treatment

It has an incubation period of 10 to 12 days, followed by a prodromal phase of 3 to 5 days characterized by low-grade fever, conjunctivitis, headache, rhinitis, cough, and the appearance of characteristic spots on the oral mucosa called Koplik's spots.

On some occasions the prodromal phase can be very severe with a very high fever, seizures and even the appearance of pneumonia. In these cases, all the prodromal manifestations described above are much more intense.

Between the third and seventh day, after a sudden increase in temperature, often between 40 and 40.5⁰C, an erythematous rash appears on the face, which then becomes generalized, and lasts from two to four days or up to seven days in more severe cases.

The first days of the eruptive phase the general state is greatly affected. Then the temperature drops sharply and, although the rash persists, the patient looks much better. In general, in most cases it remits without major complications.

However, measles can generate serious complications from otitis media, pneumonia to encephalitis with a high mortality rate for these cases. The possibility of contagion persists for up to five days from the beginning of the eruption. There is no specific treatment and treatment is symptomatic.

Vaccine

In regions where there is still a significant casuistry of this disease, the measles vaccine is administered in the first semester of life. Meanwhile, in other regions where the disease is more controlled, it is usually delivered later (12 to 15 months).

This vaccine is usually combined with other vaccines such as the rubella and mumps (triple viral) vaccines. As the host of the virus is strictly human, eradication of this disease is, in theory, possible.

2- Diphtheria

It is an acute bacterial infection caused by the toxin of a Corynebacterium diphtheriae bacteria. It was one of the leading causes of infant mortality in the early 20th century before the introduction of the vaccine.

This bacterium has an exclusive habitat on the mucous membranes and on the skin of man. It is transmitted through droplets of saliva emitted by coughing or breathing and by contact with infected skin lesions.

Before the development of the vaccine and its massive application, this disease mainly affected children under 15 years of age. The mortality rate was 5 to 20% in infected patients. Interestingly, this rate is maintained in recent outbreaks.

Signs and symptoms

The incubation period is 1 to 5 days, then pharyngitis appears with the formation of pseudomembranes that can spread and obstruct the upper airways, cause suffocation and death of the patient. The complications of diphtheria are usually cardiac and neurological, which can lead to death.

Treatment and vaccine

Diphtheria must be treated immediately to reduce the risk of complications and mortality. The main element of treatment is the intramuscular or intravenous administration of an antitoxin against diphtheria.

Antibiotics reduce bacterial growth, but have no effect on toxin-generated lesions. Diphtheria still persists in many countries, especially those that are poorer or developing. In fact, several epidemics have occurred in the last 10 years.

Diphtheria vaccine is made from diphtheria toxoid, a harmless form of the toxin. It is supplied between two months and 7 years. 3 initial serial doses are given every two months and a booster 6 to 12 months after the third dose.

3-

It is an infectious disease that produces an often fatal spastic paralysis, caused by a neurotoxin (tetanospasmin) produced by Clostridium tetani. It is a disease spread throughout the world and has not yet been eradicated in industrialized countries.

Symptoms, treatment and vaccination

The bacteria is present in its sporulated form in the soil, on dirty surfaces and the digestive tracts of some animals. It enters the body through injuries, dirty wounds, open fractures, chronic ulcers or by medical actions carried out without adequate asepsis.

The incubation period is 4 to 21 days. The disease begins with spasms generally of the facial muscles (trismus, sardonic laughter) followed by spasms of the back muscles (opisthotonos) and generalized tonic seizures.

If left untreated, it is almost always fatal, especially in young children and older people. Even with optimal treatment with human tetanus immunoglobulins and early antibiotics, mortality from tetanus is high.

The disease reservoir cannot be removed, but vaccination is very effective in preventing it. Tetanus vaccines are made with tetanus toxoid and supplied in conjunction with other preparations such as diphtheria, pertussis, poliomyelitis, etc.

4- whooping cough

Whooping cough is a highly contagious bacterial disease caused by Bordetella pertussis, which affects the lower respiratory tract. It is a disease that is considered re-emerging and is particularly serious in infants.

It has a prolonged evolution for several weeks with persistent cough for more than three weeks, generally without fever and with a characteristic inspiratory sound accompanied by bluish discoloration of the mucosa (cyanosis), apnea (cessation of breathing) followed by vomiting.

It is easily transmitted by close contact through coughing. Although vaccination has been an effective preventive measure, pertussis continues to be a threat due to the increase in cases in unvaccinated infants because they are still very young. There are also cases of adolescents and young adults, since the protection conferred by vaccination only persists for a few years.

The pertussis vaccine is included in the vaccination schedule for infants and children from two months of age to six years. Acellular pertussis vaccines are currently available, which allows the placement of late boosters.

5- Hepatitis

Hepatitis is an acute inflammatory disease of the liver produced by hepatotrophic RNA viruses and which give it the name of hepatitis A, B, C, D and E depending on the virus involved. Hepatitis A is the most common. Hygienic conditions and environmental sanitation reduce the hepatitis A virus in the population, but do not eliminate it.

Hepatitis A and E are not known to cause chronic disease, on the contrary, hepatitis B, C and D cause significant morbidity and mortality through chronic liver infections.

Symptoms treatment and prevention

Specific manifestations of the disease are seen more frequently in adults. On the other hand, in children under 5 years of age it may go unnoticed or show general and nonspecific manifestations.

The incubation period ranges from 15 to 45 days. The initial changes in the liver are similar for the five types of hepatitis, generating symptoms characterized by fever, headache, myalgias, fatigue and gastrointestinal disorders. A yellow discoloration of the skin and mucosa (jaundice) also appears more frequently in adults.

The disease can be prolonged, with an acute phase of about a month and a convalescence that can last up to six months. Depending on the type of virus, complications related to chronicity may appear, such as cirrhosis and liver cancer. Some cases present as fulminant hepatitis.

There is no specific treatment for hepatitis. The reservoir of the virus is strictly human. Transmission of the virus is by the oral-fecal route from individual to individual, or through contaminated food or water.

There are vaccines for hepatitis A and hepatitis B, but there are no vaccines available against hepatitis C, D, or E.

6- Meningococcal meningitis

Meningococci are the leading cause of bacterial meningitis and septicemia. Serologic groups A, B, C, Y, and W135 produce the majority of invasive infections. It affects young children and young adults.

It begins as an infectious syndrome with fever, headache, and vomiting. Concomitantly, signs of meningitis appear, such as stiff neck or lethargy, which can progress to disorders of consciousness, coma and death.

The contagion is by air. It has a high mortality and leaves dramatic sequelae. It can be prevented, as there are several vaccines against some serological types.

7- Tuberculosis

It is a contagious bacterial disease caused by Mycobacterium tuberculosis. It is the second leading cause of death from infectious diseases in the world.

Transmission is by air and the most common clinical form of active tuberculosis is pulmonary. Symptoms are chronic cough, moderate fever, night sweats, tiredness, decreased appetite, and weight loss.

Tuberculosis can affect other organs besides the lung such as the spleen, liver, bone marrow or meninges among others. Treatment includes anti-tuberculosis antibiotics for several months or years.

The vaccine is called BCG and it is an intradermal vaccine that is given at birth with a booster before school.

8- Typhoid fever

Typhoid fever is a bacterial infection caused by salmonella typhi, which causes a very severe enteric fever. It is a disease that is still registered in countries with very poor hygienic conditions. It is transmitted by direct contact, or by water and food contaminated with feces.

Symptoms appear after an incubation period of 7 to 15 days, with abdominal pain, fever, myalgias, anorexia (loss of appetite) and initially profuse diarrhea, and then pass to a stage of constipation. Nausea, vomiting, coughing, and epistaxis are not common and their presence indicates complications.

Common complications are digestive bleeding, intestinal perforation or encephalitis, among others. Treatment includes antibiotics and rehydration, which usually work well when there are no major complications.

Prevention includes sanitary measures, detection, treatment of healthy carriers, especially in personnel who handle food, and vaccination.

9- Rubella

Rubella is a contagious eruptive disease of viral origin. It can be asymptomatic. It causes significant damage to the fetus if it occurs in the early stages of pregnancy, generating auditory, ophthalmic, craniofacial and cardiac malformations.

The incubation period is about two weeks. Symptoms include mild fever, malaise, conjunctivitis, suboccipital lymph nodes (swollen lymph nodes in the neck), and a transient erythematous rash. It is transmitted by drops that come out of the breath.

To prevent rubella, there is a vaccine that is often included in a mixture called MMR and includes mumps and measles.

10- Anger

Cholera is an intestinal disease caused by the toxin from the bacterium vibrio cholerae. This condition has caused devastating epidemics throughout the world at many times in history.

It is spread by water and food contaminated with human feces and is a disease that strictly affects humans. After an incubation that can go from hours to four days, there is an acute watery diarrhea with vomiting and rapid dehydration that, if not treated in time, ends with the death of the patient.

Hygiene and environmental sanitation are fundamental pillars of the prevention and fight against cholera. Treatment is symptomatic and is based on rehydration. Since the disease is caused by a toxin, killing the bacteria does not reduce the effect of the toxins present.

Oral cholera vaccines are an additional tool in the fight against cholera, but they do not replace hygienic and sanitary measures.

References

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