DIPHTHERIA

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Context: Recent outbreaks in Nigeria, Guinea, and neighbouring countries highlight the need for updated diphtheria treatment guidelines due to limited previous guidance and clinicians' limited experience in affected regions.

Details

• In response to outbreaks of diphtheria in regions including Nigeria, Guinea, and neighbouring countries in 2023, the World Health Organization (WHO) has released comprehensive clinical management guidelines for diphtheria.
• These guidelines aim to address the urgent need for evidence-based practices in treating diphtheria, especially in areas where clinicians may have limited experience managing this disease.

New Guidelines and Recommendations

• WHO's guidelines focus on the clinical management of diphtheria, providing updated recommendations on the use of Diphtheria Antitoxin (DAT) and antibiotics. Notably, there is a global shortage of DAT, prompting the need for evidence-based recommendations on its usage.
• The guidelines emphasize the use of macrolide antibiotics (azithromycin, erythromycin) over penicillin antibiotics in patients with suspected or confirmed diphtheria.

Rationale for Antibiotic Choice

• The preference for macrolide antibiotics is based on recent evidence indicating increasing resistance to penicillins and lower resistance to macrolides.
• Local antimicrobial susceptibility testing is crucial to ensure appropriate antibiotic use, and the choice of macrolide depends on availability and feasibility.

Treatment Options

• Current treatments for diphtheria include neutralization of unbound toxin with DAT, antibiotics to prevent bacterial growth, and monitoring/supportive care to prevent and treat complications such as airway obstruction and myocarditis.
• Urgent airway intervention may be necessary in cases of imminent airway obstruction, with options including basic airway manoeuvres, endotracheal intubation, cricothyroidotomy, and tracheostomy.

New Recommendations

• WHO recommends using macrolide antibiotics instead of penicillin antibiotics in patients with suspected or confirmed diphtheria.
• Routine sensitivity testing prior to administration of DAT is not recommended.
• An escalating dosing regimen for DAT is suggested based on disease severity and time since symptom onset, rather than a fixed dose for all patients.

Current treatment options for diphtheria include:

●Diphtheria Antitoxin (DAT): This is used to neutralize the unbound toxin in the body. ●Antibiotics: These are administered to prevent further bacterial growth. According to recent recommendations from the World Health Organization (WHO), macrolide antibiotics such as azithromycin and erythromycin are preferred over penicillin antibiotics in patients with suspected or confirmed diphtheria. This is due to increasing resistance to penicillins and lower resistance to macrolide antibiotics. ●Monitoring and Supportive Care: This is essential to prevent and treat complications, such as airway obstruction and myocarditis. Urgent airway intervention may be required in patients with imminent airway obstruction, and the specific approach (basic airway manoeuvres, endotracheal intubation, cricothyroidotomy, or tracheostomy) depends on the experience of the treating medical personnel.

New recommendations from the WHO include:

●Macrolide Antibiotics: WHO recommends the use of macrolide antibiotics (azithromycin, erythromycin) over penicillin antibiotics in patients with suspected or confirmed diphtheria. Antibiotics should be administered alongside DAT and should not be delayed. ●Routine Sensitivity Testing: WHO recommends not performing routine sensitivity testing prior to the administration of diphtheria antitoxin (DAT). ●Escalating Dosing Regimen for DAT: WHO suggests an escalating dosing regimen for DAT based on disease severity and time since symptom onset, rather than a fixed dose for all patients with suspected or confirmed symptomatic diphtheria.

Diphtheria

• Diphtheria is a severe bacterial infection caused by Corynebacterium diphtheriae. This bacteria produces a toxin that damages respiratory tract tissues, leading to symptoms such as sore throat, fever, difficulty swallowing, hoarseness, and cough.
• The infection can also affect the skin, eyes, genitals, and may result in complications like heart problems, nerve damage, kidney failure, and bleeding disorders.

Transmission and Risk Factors

• Diphtheria spreads through respiratory droplets, contaminated objects, or through skin wounds. People with low immunity or those not vaccinated are at higher risk. The incubation period is usually 2 to 5 days.

Symptoms

• Symptoms depend on the site of infection. Respiratory diphtheria includes a sore throat, fever, difficulty swallowing, hoarseness, cough, swollen lymph nodes, and a grey membrane on the throat. Cutaneous diphtheria affects the skin, causing ulcers covered by a grey membrane, redness, swelling, and pain.

Complications

• Diphtheria can affect the heart, nerves, kidneys, and blood cells, leading to serious complications like myocarditis, peripheral neuropathy, kidney failure, and thrombocytopenia.

Treatment

• Early diagnosis is crucial. Treatment involves antibiotics (like penicillin or erythromycin) to kill the bacteria and antitoxin to neutralize the toxin. Supportive care includes oxygen therapy, fluids, blood transfusions, cardiac medications, and, in severe cases, surgery.

Prevention

• Vaccination is the best prevention. There are four types of vaccines (DTaP, Tdap, DT, Td) that protect against diphtheria. Vaccination provides immunity for about 10 years, and levels can be checked with antitoxin blood tests. People exposed to diphtheria should receive antibiotics and antitoxin, even if vaccinated, as a preventive measure.

Conclusion

• These guidelines from the WHO provide updated and evidence-based recommendations for the clinical management of diphtheria, addressing the urgent need for standardized practices in treating this serious bacterial infection. By emphasizing the use of macrolide antibiotics and providing guidance on DAT administration, these guidelines aim to improve patient outcomes and reduce the burden of diphtheria in affected regions.

Must Read Articles:

New recommendations from the WHO include: https://www.iasgyan.in/daily-current-affairs/diphtheria

DPT3 Immunization: https://www.iasgyan.in/daily-current-affairs/dpt3-immunisation

NCDC Survey on Antimicrobial Usage: https://www.iasgyan.in/daily-current-affairs/ncdc-survey-on-antimicrobial-usage

PRACTICE QUESTION Q. Which of the following factors contribute to the development of antibiotic resistance in bacteria? 1. Overuse and misuse of antibiotics 2. Natural selection favoring resistant bacteria 3. Poor sanitation and hygiene practices 4. Sharing antibiotics with others Select the correct code: A) Only one B) Only two C) Only three D) All four Answer: D Explanation: Overuse and misuse of antibiotics: The excessive and inappropriate use of antibiotics, such as not completing a prescribed course or using them without a prescription, can contribute to the development of antibiotic resistance. This occurs because bacteria that survive exposure to antibiotics may develop resistance mechanisms. Natural selection favours resistant bacteria: Bacteria reproduce rapidly, and the use of antibiotics creates selective pressure. Resistant bacteria have a survival advantage in the presence of antibiotics, leading to their increased prevalence over time. Poor sanitation and hygiene practices: Inadequate sanitation and hygiene can facilitate the spread of bacterial infections, leading to increased antibiotic use. Additionally, environments with poor hygiene may harbour antibiotic-resistant bacteria, contributing to the overall resistance problem. Sharing antibiotics with others: Sharing antibiotics, either through self-medication or informal sharing of medications, can contribute to the spread of antibiotic resistance. Incomplete courses of antibiotics, when shared, can lead to the survival of resistant bacteria.