​Kembara Xtra - Medicine - Pertussis

​Kembara Xtra - Medicine - Pertussis
Highly contagious among intimate contacts; also known as "100 day cough"; hosts humans
Adults are the most prevalent reservoir, and all ages and regions are affected.
 Seasonality: peaks late summer-autumn; can occur year-round Transmission: person-to-person via aerosolized droplets Typical incubation period: 7 to 10 days Effective vaccine: available
System(s) affected: respiratory Immunity: neither 100% nor lifetime immunity with either infection or vaccine

Epidemiology Incidence: 48,277 cases recorded in the United States (2012 was the most recent peak year); 24.1 million cases and approximately 160,700 deaths annually worldwide.

Pathophysiology and Etiology 
Infectious process that is toxin-mediated and has a preference for ciliated respiratory epithelium. Common organisms:
Bordetella parapertussis and pertussis, respectively
Genetics
No inherited tendency is known


Exposure to a proven case, non- or under-vaccinated newborns and children, premature birth, chronic lung disease, immunodeficiency (such as AIDS), and age 6 months (which accounts for 90% of pediatric pertussis hospitalizations) are risk factors.

Prevention strategies include: public health measures, surveillance, outbreak management, care for those who have been exposed, prevention programs, vaccinations (4), and booster shots after the initial pertussis vaccination series for children. - Immunization of the mother during each pregnancy - Immunization is recommended for all adults, especially medical professionals who work closely with children under the age of one.
Child Safety Considerations
Tdap during each pregnancy, ideally between 27 and 36 weeks' gestation; cocooning; and Tdap advised for all those in close contact with infants under the age of one. Aspects of Geriatrics
The following factors enhance the risk of problems from pertussis in older people: Immune system alterations brought on by aging Comorbid medical conditions

Infantile apnea, secondary bacterial pneumonia, sinusitis, seizures, encephalopathy, and incontinence are all related conditions.

Pertussis exposure, a sneaky onset, and an incubation period of 7 to 10 days (range, 5 to 21 days) are all factors in the diagnosis.

clinical assessment 

Three steps of conventional pertussis take place over a period of six to ten weeks (6): - Catarrhal phase: moderate cough, fever, and rhinorrhagia
- Paroxysmal phase: Increased frequency and severity of coughing that occurs in bursts. This phase is sometimes accompanied by an inspiratory whoop and/or posttussive vomiting.
- Convalescent phase: The frequency and severity of coughing paroxysms decline.
In adults and unvaccinated children, the classic presentation is more frequent.

Caution: If there are no problems or paroxysms, the physical examination may be normal.
Infants under the age of six months may present in an unusual way.

Multiple Diagnoses 
Additionally, B. parapertussis, Mycoplasma pneumoniae, Chlamydia trachomatis, and Chlamydophila pneumonia can all result in sporadic, protracted coughing. Respiratory syncytial virus, Bordetella bronchiseptica, Bordetella holmesii, Adenovirus


Initial test results from the laboratory and imaging
False results can occur in the following circumstances: - Individuals who have been previously immunized - After starting the right antibiotic - After 2 weeks from the start of the cough - With improper collection or handling - Nasopharyngeal culture (gold standard): best results within first 3 weeks of cough onset - Polymerase chain reaction (PCR) assays: quick turnaround time; good within first 3 weeks - Serology:
- Available commercially; not FDA-approved for diagnosis


Tests in the Future & Special Considerations

 Assessment and monitoring for related conditions and complications  A chest radiograph with two views to determine whether pneumonia is present In infants with seizures or apparent life-threatening episodes (ALTEs), EEG/neuroimaging may be evaluated.
Macrolide-treated infants younger than one month old should be watched for the potential onset of hypertrophic pyloric stenosis.

Neonatal pertussis patients should be hospitalized with continuous cardiopulmonary monitoring; more oxygen may also be required, as well as mechanical ventilator assistance.

Medication In cases of significant clinical suspicion or in those who are at high risk for complications, begin empiric antibiotic medication after diagnostic testing is completed.
After a cough has developed, antibiotic medication may help to prevent further spread, but it is not anticipated that it will alter clinical symptoms.
 Favorite antibiotics:
Patients older than six months:
 Azithromycin, clarithromycin, or erythromycin - With caution, azithromycin is preferred for newborns under one month old.
Initial Line
The first-line drug for both treatment and postexposure prophylaxis is azithromycin (5-day course).


Caution 

Macrolides have been linked to infantile hypertrophic pyloric stenosis in newborns under one month old.
Consultation and oversight are advised.
With azithromycin, fatal cardiac dysrhythmias have been documented.
In people with proarrhythmic disorders and prolonged QT, caution is advised.
Trimethoprim/sulfamethoxazole (TMX/SMX), second line (for patients older than 2 months), if: Macrolide intolerance Macrolide resistance

TMP/SMX is not recommended for use in newborns under two months old.
It is not advised to give clarithromycin to infants younger than one month.


Referral Assessment and care of young children under the age of six months, particularly those who were born prematurely, are imunized, or need to be hospitalized.


Further Therapies 

Treatments for the cough associated with pertussis, such as corticosteroids and 2-adrenergic agonists, have not consistently been effective.


Admission 

In addition to standard precautions, hospitalized patients should be isolated with respiratory precautions for 5 days after the start of effective antibiotic treatment and for 3 weeks after the onset of paroxysms in older patients if antibiotics are not used. Gentle suctioning of nasal sebum may be necessary to ensure adequate nutrition. IV fluids indicated for dehydration and when oral fluids are either contraindicated or poorly tolerated. 
Respiratory monitoring, including pulse oximetry; teaching each family the value of immunization; and talking with each family about chemoprophylaxis.

Constant Supportive Care


Infants who received EES or azithromycin for hypotrophic pyloric stenosis should be followed up on.
 Follow-up on the lungs and/or the nervous system as necessary
Patient Monitoring Patients who are critically ill or have compromised health may require ICU care.


Diet 
To treat dehydration or to make up for inadequate oral intake, IV fluids or nutrients may be necessary.

Prognosis: Most patients will fully recover; infants under 6 months of age will experience the highest levels of morbidity and mortality; the global mortality rate is predicted to be 160,799 per year.


Complications 
Infants are most at risk for complications, which include apnea, cyanosis, and sudden death. Children are more likely to experience complications including conjunctival hemorrhage, inguinal hernia, pneumonia, and seizures.  More common in adults versus teenagers: sinusitis, otitis media, pneumonia, weight loss, dizziness, rib fracture, urine incontinence, seizures, and encephalopathy

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