Tags: Chlamydia

Chlamydia

Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae are among the most prevalent microbial pathogens in humans worldwide. C trachomatis is responsible for a variety of sexually transmitted disease (STD) syndromes in both sexes. In addition, certain serotypes of C trachomatis are responsible for trachoma, the most common infectious cause of blindness in humans. C psittaci is a zoonotic pathogen associated with atypical pneumonia.

Chlamydia Trachomatis Infections

C trachomatis is associated with urethritis, proctitis, conjunctivitis, and arthritis in women and men; epididymitis in men; and mucopurulent cervicitis (MPC), acute salpingitis, bartholinitis, and the Fitz-Hugh and Curtis syndrome in women (Box 1). C trachomatis and Neisseria gonorrhoeae (see site) coinfections are common in women with MPC and men with urethritis. In men, C trachomatis is the most common etiologic agent of the nongonococcal (NGU) and postgonococcal urethritis (PGU) syndromes.

Mycoplasma Pneumoniae Infection & Disease

Infected humans are the only source of M pneumoniae organisms for transmission to new susceptible hosts. M pneumoniae is spread from one individual to another by respiratory droplets produced by coughing. Individuals at any age can be infected and develop disease, but those between the ages of 5 and 20 years are most often affected. M pneumoniae is a leading cause of pneumonia in school-aged children and young adults — especially those in military and college populations.

Important Anaerobes: Clinical Syndromes

Box 1 summarizes different clinical syndromes associated with anaerobic bacteria. The sections that follow describe the various syndromes, including clinical findings. For some syndromes, specific diagnosis and treatment information is included as well.

Neisseria Meningitidis

N meningitidis is found only in humans and is a member of the normal oropharyngeal flora in 5-15% of healthy adults and children. In crowded or closed populations such as in boarding schools or military camps, higher carriage rates are observed.

Neisseria Gonorrhoeae & Neisseria Meningitidis

Neisseria gonorrhoeae was first described by Albert Neisser in 1879, in the ocular discharge and exudate from newborn infants with conjunctivitis. Descriptions of a condition resembling the disease gonorrhea can be found in the written record as early as 130 AD, when Galen created a descriptor for the malady by using the Greek words gonos (seed) and rhoea (flow) to characterize what was believed to be the morbid loss of semen.

Pneumonia

This section focuses on the clinical findings, diagnosis, and treatment of pneumococcal pneumonia. Bacteremia, progressive respiratory failure, and hemodynamic instability (ie, septic shock) are the most severe complications of pneumococcal pneumonia. As noted above, patients with either anatomic or functional asplenia are at particularly high risk for sepsis. Spread of infection via either contiguous extension or hematogenous routes constitutes the basis of extrapulmonary complications.

Hantaviruses

Hantaviruses are members of the bunyavirus group, which is the largest family of viruses and contains several human pathogens including California encephalitis virus (see site). The hantavirus group was first recognized as causing hemorrhagic fevers with renal failure in Asia and Eastern Europe but became much more prominent in the United States when the hantavirus pulmonary syndrome was described in the United States. Hantaviruses have been found throughout the world in a variety of rodents and other species.

Adenoviruses: Clinical Syndromes

Adenoviruses cause primary infection in children and, less commonly, adults. Reactivation of virus occurs in immunocompromised children and adults. Several distinct clinical syndromes are associated with adenovirus infection (Box 1). Acute pharyngitis is usually nonexudative but is associated with fever.