Diphtheria Toxin and Symptoms Quiz

Diphtheria

• Diphtheria is a disease caused by Corynebacterium diphtheriae, a non-toxigenic strain that produces a powerful exotoxin.
• The toxin causes damage to the heart and kidneys, and can lead to paralysis of the soft palate and pharynx, ultimately resulting in death.
• Treatment involves antibiotics and diphtheria antitoxin.
• Early symptoms include sore throat and fever, while later symptoms involve the formation of a tough, grayish pseudo-membrane in the throat, which can block air passages to the lungs and lead to death.
• The disease is diagnosed by culturing a sample from a throat swab, and treatment is started immediately in suspected cases.
• Diphtheria can be prevented by vaccines such as DTap, Tdap, and Td.

Pertussis (Whooping Cough)

• Pertussis is a lower respiratory tract infection caused by Bordetella pertussis.
• The bacterium produces a capsule that attaches to ciliated cells in the trachea, and a tracheal cytotoxin that damages ciliated cells and shuts down the ciliary escalator.
• The disease has a 5-10 day incubation period, and symptoms include cold-like symptoms, uncontrollable violent coughing, and gasping for air.
• Diagnosis is by culture of a throat mucus sample.
• Pertussis is highly contagious and can be prevented by DTaP and Tdap vaccines.

Pneumonias

• Typical pneumonia is caused by bacteria, such as Streptococcus pneumoniae, and is also known as bacterial pneumonia or pneumococcal pneumonia.
• Atypical pneumonia is caused by non-bacterial microbes, such as Influenza virus, and is also known as viral pneumonia or fungal pneumonia.
• Atypical pneumonia is seen in immunocompromised hosts, such as those with HIV/AIDS.

Pneumococcal Pneumonia

• Pneumococcal pneumonia is a lower respiratory tract infection caused by Streptococcus pneumoniae.
• The bacterium produces a very large capsule that allows it to grow and multiply outside macrophages, eventually rupturing and releasing bacteria into the lungs and cardiovascular system.
• Symptoms include chronic symptoms, persistent low-grade fever, night sweats, weight loss, weakness, and bloody cough, which indicates alveolar damage.
• The disease can spread from the primary lesion to other areas of the lung, liver, and nervous system, known as miliary tuberculosis.

Tuberculosis

• Tuberculosis is a chronic bacterial infection caused by Mycobacterium tuberculosis.
• The disease is diagnosed by tuberculin skin test, chest X-ray, and acid-fast staining of a sputum sample.
• Treatment involves a minimum of 6 months of multi-drug therapy, and can be prevented by the BCG vaccine.
• Tuberculosis is a leading cause of death from infectious diseases worldwide, and 10 million people develop the disease annually, with 2 million deaths.

Influenza (Flu)

• Influenza is a viral infection caused by the Influenza virus, which has eight RNA segments and spikes.
• The virus undergoes antigenic variation, involving genetic recombination and the formation of hybrid viruses.
• The disease is transmitted by droplet and airborne transmission, and has a high mutation rate.
• Symptoms include chills, fever, headache, and muscle aches, and can lead to viral pneumonia.
• Influenza is difficult to diagnose from clinical symptoms, and can be treated with antivirals such as Zanamivir and Oseltamivir.
• The disease is prevented by a multivalent vaccine, which is determined annually, and does not provide long-term immunity.

Coronavirus Disease 2019 (COVID-19)

• COVID-19 is a viral infection caused by SARS-CoV-2, which belongs to the Coronaviridae family.
• The virus has a single-stranded RNA, is enveloped, and has spikes.
• The disease was first detected in open food markets in Wuhan, China in December 2019.
• COVID-19 has a high mutation rate, and several human variants have been identified, including the Alpha, Beta, Gamma, Delta, Epsilon, and Omicron variants.
• The disease is transmitted by zoonotic, droplet, and airborne transmission, and can be prevented by washing hands frequently, maintaining social distancing, and practicing respiratory hygiene.
• Vaccines have been developed, including the Pfizer-BioNTech mRNA vaccine, Moderna mRNA vaccine, and Johnson & Johnson/Janssen viral vector vaccine.