It is a disease that reaches a mortality rate of 20% in children under 5 years and elderly. In Italy it has been almost completely eradicated, but to prevent the return of this dangerous disease it is necessary to continue to keep the vaccination coverage high
Angela and Marco, parents of little Alice, are consulting the vaccination calendar in view of the call that their little girl must carry out. Among the listed vaccines find that against diphtheria. “But does it still exist?” The mother’s mother wonders perplexed. “If it is a disease now eradicated, why do we have to vaccinate it?” The answer lies in the need to keep the protection in the population high to avoid the return of this dangerous infection.
Although it is rare today in countries with a high vaccination coverage, diphtheria, acute infectious disease caused by a bacterium, remains in fact severe pathology which can cause potentially lethal complications. It is mainly spread through the respiratory droplets emitted with cough and sneezed by infected people, but it can also be transmitted through direct contact with skin lesions or contaminated surfaces. In the past, the diphtheria was one of the main causes of childhood death, and it is only thanks to the introduction of the mass vaccination that cases have drastically reduced to high -income countries.
DIFTIRITES: the symptoms
The diphtheria mainly affects the upper respiratory tract and manifests itself with symptoms such as sore throat, moderate fever, weakness and breathing difficulty. One of the most characteristic signs is the formation of a grayish pseudomembrane on the tonsils, the pharynx and the larynx, caused by the action of the Difterica toxin. This membrane can become thus thick as to obstruct the airways, causing serious breathing difficulty and, in the most critical cases, asphyxiation.
Difterica toxin can enter the bloodstream and hit several organs, causing potentially lethal complications. Among the most serious we find:
- Myocarditisor inflammation of the heart muscle that can lead to heart failure.
- Neuropathiesthat is, they give the peripheral nerves, with consequent motor difficulties and paralysis.
- Renal failuredue to the toxic action on the kidneys.
In the absence of timely treatment with antitoxine Difterica and antibiotics, the mortality of the diphtheria can reach 10% of cases, reaching up to 20% in children under 5 years and in the elderly.
DIFTIRITES: the causes
Difterite is caused by the infection of the bacterium Corynebacterium diphtheriaewhich is mainly transmitted by air, through contact with the respiratory secretions of infected people. There are four main strains of Corynebacterium diphtheriae (Gravis, Mitis, Intermediate and Belfanti), some of which produce more aggressive toxins.
Not all strains of Corynebacterium diphtheriae they produce difteric toxin. The bacterium becomes toxigenic only when it is infected with a virus capable of infecting the bacteria (bacteriophagus) that transports the gene for toxin. This toxin inhibits the protein synthesis of human cells, leading to cell death and damage to tissues.
THE risk factors For infection they include:
- lack of vaccination or insufficient vaccination references;
- Travel to endemic areas, where the disease is still widespread (such as some areas of Asia, Eastern Europe, Brazil and Africa);
- contact with infected individuals or asymptomatic carriers of the bacterium;
- overcrowding conditions and poor hygiene;
Skin difterite
In addition to the respiratory form, the diphtheria can manifest itself at the skin level, especially in tropical climates or in precarious hygiene conditions. This variant presents itself with chronic ulcerative lesions covered by a grayish membrane and can associate with secondary bacterial infections. There skin difterite it is common among the people who live in situations of extreme poverty or with precarious hygieneand can act as a tank of infection for the spread of the disease.
In the most serious cases, the toxin produced by the bacterium can spread in the blood, causing the same systemic effects as the respiratory shape, such as damage to the heart and nervous system.
DIFTIRITES AND VACCINO
Vaccination represents the only effective tool against diphtheria. The antidifteric vaccine is administered in combination with that for tetanus and pertussis (dtpa) or inside the hexavalent vaccine, which also protects against tetanus, pertussis, polio, hepatitis B and Haemophilus influenzae Type B. In Italy, the vaccination calendar provides:
- Three doses in the first year of life (on the third, fifth and eleventh month) with the hexavalent vaccine;
- A reference to 6 years with the DTPA vaccine;
- A call to adolescence (around 14 years);
- Further calls every 10 years in adulthood to maintain protection.
The antidifteric vaccine is extremely effective, with a Protation close to 100% After the complete vaccination cycle. However, immunity tends to decrease over time, which is why The calls are fundamental to prevent any recovery of the disease.
Dipterite in Italy
Thanks to vaccination, the DIFTIRITES IN ITALY It was almost completely eradicated: The latest autochthonous cases date back to the 90s. However, some import cases have recently been reported, linked to travelers from countries where the disease is still present. The reduction of vaccination covers represents a concrete risk, especially in a context of globalization and frequent movements.
In the early decades of the twentieth century, the diphtheria was one of the main causes of death in Italian children. With the introduction of the Mandatory vaccination in 1939the cases began to decrease drastically, until their almost total disappeared since the 1980s. However, in the absence of a widespread immunity, the risk of reintroduction of the disease remains, especially if the vaccination covers should drop below the threshold necessary for the immunity of flock.
Therefore, although the cases are now rare in Italy, the maintenance of high vaccination covers is essential to prevent the return of the disease. Informing the population about the importance of vaccines and ensuring respect for the vaccination calendar are fundamental actions to protect the most vulnerable bands of society, especially children and the elderly.
