Lecture on pertussis

2021-03-23 12:00 AM

Bacteria that secrete endotoxins (Pertussis toxin) include two types: heat-resistant and heat-resistant, lymphocytic factor (LPF), histamine-sensitive factor (HSF), and FHA agglutination factor.

Define

Pertussis is an acute infectious disease caused by pertussis bacillus. The disease is transmitted by the respiratory tract, clinically manifested by severe, special coughing spells with many complications.

Thanks to the preventive vaccines, the morbidity rate has been reduced, but mortality is still high, especially in the new-born age group.

Research history

The disease was first described in the 1640s, called Pertussis because of dry, whooping coughs. Pertussis bacillus was isolated by Bordet-Gengou in 1990.

The disease occurs all over the world. In 1997, there were more than 45 million illnesses and 409,000 deaths worldwide.

Epidemiology

Pathogens

Pertussis bacillus belongs to the family Pavrobacteriaceae.

Gram-negative bacilli, two pointed tips, size 0.3-0.5 ´ 1-1.5 m m, aerobic, non-mobile, does not produce spores. Bacteria poorly tolerate heat, die in sunlight after 1 hour, and die at 55 °C after 30 minutes.

Bacteria that secrete endotoxins (Pertussis toxin) include two types: heat-resistant and heat-resistant, lymphocytic factor (LPF), histamine-sensitive factor (HSF), and FHA agglutination factor.

Inoculum

Are the patients with pertussis disease. The disease spreads most strongly during the first 1-2 weeks of illness. Up to now, it has not been determined that there are healthy people carrying bacteria.

Infection

The spread of the disease is very high. The disease spreads through the respiratory tract, caused by bacteria in saliva droplets shot from the patient's nose or mouth when coughing and sneezing directly to the healthy person. Range is less than 3 meters.

Sense of the body

Every age group, gender, ethnicity, or geographic area can get whooping cough, but mostly children 1-6 years old. The younger the child, the more severe the illness.

After having a pertussis disease, the patient has a lifelong immunity, which is very rare. The disease usually occurs all year round, with local circulation.

Whooping cough persists around the world and has seen an increase in recent years.

Mechanism of pathogenesis and pathology

Mechanism of pathogenesis

Bacterial toxin (Pertussis toxin - Ptx) stimulates directly into the nerve receptors of the respiratory tract mucosa causing typical coughing attacks, on the other hand, the central nervous system affecting directly respiratory center in the medulla, causing manifestations of respiratory disorders, if severe, can stop breathing. The toxin can also cause euphoria foci in the respiratory center, resulting in prolonged reflex coughing. The spread of toxins in the central nervous system can lead to the manifestation of encephalitis - a serious complication of pertussis disease.

Lung lesions: Mainly caused by bacterial toxin that causes acute respiratory tract inflammation and mucosal stimulation to increase mucus secretion. Lesions mainly in bronchi and bronchioles.

Pathological anatomical injury

The main lesions in whooping cough are:

Constriction of the bronchi and bronchioles. The air-bronchial mucosa is damaged in place and has increased secretion of mucus.

Inside the alveoli appeared many fluid and tissue, congested walls.

Can see oedema in the brain organization and damage to nerve cells.

clinical

Divide the clinical form

By age

Whooping cough in new-born babies: Usually progresses seriously, high mortality.

Whooping cough in adults: Uncommon. Clinical manifestations are usually mild, persistent cough, but not very much breathing in, little vomiting.

According to the level

Rude form: No coughing, just sneezing a lot.

Mild: A mild, short, and atypical cough that does not cough up much sputum. Common in children who have been vaccinated against pertussis, but the antibody is low and persistent. This can often be difficult to diagnose.

Typical body: There are typical, special coughs.

Typical clinical symptoms are typical

Incubation period: 2-30 days (average 5-12 days).

Onset period (also known as the exudate phase, the long inflammatory phase): Usually from 3-14 days with manifestations.

Low-grade fever slowly increases.

Symptoms of respiratory tract inflammation: Dry cough, sneezing, runny nose, sore throat, gradually turn into a coughing fit.

Full-blown period (or contraction phase, period of coughing fit)

Lasts 1-2 weeks. There are typical pertussis episodes, which occur suddenly, without reason, all day and night, and cough much at night. The cough progresses through 3 phases: Cough, hissing breath and sputum production.

Cough: The cough is droopy, into a bout, each bout of 15-20 hours, the cough becomes weaker and weaker later on. A lot of coughing makes children less likely to breathe, sometimes stop breathing, pale face, red eyes, floating neck veins, watery nose.

Hissing breath: Appears at the end of coughing or alternating after each coughing sound, children hissing sounds like chickens hissing.

Sputum expectoration: When a child spits white, clear, sticky sputum like egg whites, a cough is the end of a cough. In sputum there are bacillus pertussis.

After each cough, children are listless and tired, possibly vomiting, sweating, rapid pulse, rapid breathing. Accompanying may see some of the following symptoms: Low or no fever, severe face and eyelids, tongue ulcers, listening to the lungs during a cough may see some bronchial rales (hissing, snoring).

Test

Number of peripheral blood leukocytes increased to 20,000-30,000 / mm3, of which lymphocytes were mainly (accounting for 60-80%).

Nasal and throat mucus culture to find bacillus (late results, 7-14 days).

Quicker test DFA (direct immunofluorescent assay) of nasopharyngeal mucus.

Using the immunofluorescence method gives quick results but the rate of false positives is up to 40%.

PCR (polymerase chain reaction test).

Chest X-ray: Shadows go from the hilum to the diaphragm. In addition, there may be diaphragmatic angular blurring reactions, pulmonary basal blurred vision or atelectasis images.

Recovery and recovery period

Lasts about 2-4 weeks. The number of coughing attacks gradually decreases, each one shortens, the intensity of the cough decreases, less sputum production, then completely disappears. The condition of the whole body is getting better and the child can eat and play normally.

Some children develop reflex coughs that last, even up to 1-2 months.

Diagnose

clinical

Aged susceptible (1-6 years old), has a typical cough.

Test

Peripheral blood leukocytes are elevated, mainly lymphocytes.

Throat cultures during the first week look for pathogenic bacteria.

Epidemiology

Many children are in the same group.

Differential diagnosis

In the period of inflammation should differentiate with

Spasmodic bronchitis: Often difficulty breathing at night, cough with little sputum production, or a history of allergies, illness or recurrence.

Bronchitis, viral pneumonia: Cough does not come into attack, white blood cells do not increase in peripheral blood, the disease progresses quickly after 7-10 days.

During the coughing phase should distinguish with

Bacterial respiratory infections such as bronchitis, pneumonia, pneumonia - bronchitis.

Tuberculosis - bronchial children: Detected by chest scan, sputum test and Mantoux reaction.

Symptoms

Respiratory complications

Bronchitis: Children have high fever, hear a lot of hissing lungs, snoring. Especially in some cases may experience coughing up sputum, pus. Neutrophils in peripheral blood are elevated.

Bronchiectasis: Usually the result of bronchopulmonary superinfection. Often difficult to detect on conventional radiographs. On contrast bronchoscopy in 50% of cases there is a cylindrical or tubular bronchiectasis, which will disappear once the pertussis disease is cleared.

Pneumonia - bronchitis: A common respiratory complication, especially in infants and malnourished children. Patient has high fever, difficulty breathing, hears a lot of wetness, crackling in the lungs. Chest radiograph has many irregular blurred nodules scattered on both sides. High mortality from respiratory failure if not treated promptly.

Neurological complications

Encephalitis is a serious complication of pertussis, high mortality. The child has a very high fever, lethargy, lethargy, convulsions. If they are saved, they can leave sequelae such as hemiplegia, paralysis of one limb, nerve paralysis or mental disorder.

Mechanical complications: Intestinal intubation, hernia, rectal prolapse. Severe cases may experience alveolar rupture, mediastinal airflow or pneumothorax.

Other complications: Retinal haemorrhage, eye conjunctiva, electrolyte water disorder, superinfection with other bacteria

Treatment

Specific antibiotic

Use one of the following:

Ampicillin 75-100 mg / kg / day x 7-10 days.

Erythromycin 30-50 mg / kg / day for 7-10 days.

Some commonly used brand-present: Eryenfant, erybactrim (dosage as erythromycin) and rulid (Roxithromycin) 5-8 mg / kg / day  7-10 days. clarithromycin (Biaxin), azithromycin (Zithromax) ´7-10 days

Symptomatic treatment

Reduce and cut coughing attacks

Using synthetic Histamine antibiotics: Dimedron 0.1% solution orally 5-10 ml / time ´2-3 times / day or phenergan syrup 10-20ml / day.

Valium 1-2 mg / kg / day or gacdenal 2-3 mg / kg / day.

Some cough medicines are used for adults such as codeine, benladon alcohol, not for children. It is possible to use oriental medicine pertussis syrup or one of the following brands: Antitus, antussin, solmux broncho or theralen 10-20 ml / day.

When there is a lot of vomiting: Use primperan 0.5-1 ml / day.

When breathing is difficult: Hook, suck phlegm, give oxygen.

Cardiovascular support: Coramin 0.25% ´20-30 drops / day.

When there are complications

If there is a respiratory complication due to superinfection: Use an antibiotic by injection according to the antibiotic regimen or the commonly chosen regimen is lincocin + gentamycin, Cephalosporin + gentamyxin. If you have a high fever seizure use Gardena or aminazin.

If complications of encephalitis: Actively fight brain oedema, prevent and cut seizures. The use of corticosteroids in the treatment of encephalitis still has mixed opinions.

Nurture - take care

Give your child many meals. If vomiting a lot, you may need to feed Sonde or nourish them intravenously.

Place the child in a cool place, away from drafts.

Take more vitamins A, D, C, B1, and B6.

Close monitoring of pulse and respiratory condition.

Gamma globulin specific use in the early stages of the disease, injected 2-3 ml subcutaneously / time at intervals of 48 hours (total dose 2-4 times).

Prevention

General prevention

To prevent group illness, it is necessary to isolate children with pertussis for at least 4 weeks from the typical coughing attack. The exposed children must be injected with specific Gamma globulin 0.3 ml / kg / time, injected twice at 48-72 hours intervals (protective effect against pertussis reaches 60% according to Combe and Fauchier), in which special pay attention to malnourished babies and children. In addition, erythromycin can be used to prevent pertussis in children in contact with the patient.

Specific

The pertussis vaccine has contributed to a significant reduction in morbidity and mortality. In our country, pertussis is classified as one of 6 diseases in the expanded immunization program for children.

Currently commonly used is a combination vaccine of pertussis, diphtheria, tetanus (DTaP). Newborns are vaccinated at 3 times: 2-4-6 months. Repeat after 1 year, 3 years and 5 years.

Vaccine for patients 10-18 years old is Boostrix, 11-64 years old is Adacel.