Haemophilus influenzae

• Six serotypes, based on capsular polysaccharide, have been identified (serotypes a through f). Type b strains cause invasive disease, most commonly meningitis, predominantly in infants. • Non-encapsulated or so called nontypeable strains frequently colonize the upper respiratory tract of children and adults and cause disease by contiguous spread in the respiratory tract; manifestations include otitis media in children, sinusitis in children and adults, and exacerbations in adults with chronic obstructive pulmonary disease (COPD). What is the best treatment? • Approximately 30% of nontypeable strains produce ß-lactamase, but substantial geographic variation is observed. As a result, ampicillin and amoxicillin should be used only when the susceptibility of the infecting isolate is known. Otitis media and exacerbations of COPD are usually treated empirically. • Many infections caused by nontypeable H. influenzae, including otitis media in children and exacerbations in adults with COPD, can be treated with oral antimicrobial agents. Oral agents active against nontypeable strains include amoxicillin-clavulanate, fluoroquinolones, macrolides (e.g., azithromycin, clarithromycin), and various extended spectrum cephalosporins (e.g., cefixime, cefpodoxime, loracarbef, cefuroxime). • Parenteral antibiotic therapy should be used for invasive infections caused by nontypeable strains. Agents with activity include cephalosporins (e.g., ceftriaxone, cefuroxime, ceftazidime, cefotaxime),...

It’s uncertain exactly how Hib bacteria spread, but scientists think it passes from one person to the next through respiratory droplets (through coughing or sneezing). As a result, people are generally exposed to Hib after being in close contact with someone who is infected, such as at home or in a childcare setting. While it’s not exactly clear what causes some cases to jump from a mild infection to an invasive one, it’s possible that other respiratory diseases play a role. For example, if someone is already trying to fight off a virus like influenza, the Hib bacteria might have an easier time spreading in the body. In fact, Hib disease has been a At-Risk Populations Certain individuals are more like to get invasive Hib disease than others. Like many vaccine-preventable diseases, Hib mainly affects young children. Prior to widespread vaccination, Hib accounted for 50 to 65% of cases of meningitis in kids under five years old and was the most common cause of bacterial meningitis in these kids. Diagnosis Because Hib can look like a lot of other bacterial infections, healthcare providers often rely on lab tests, in addition to a person’s medical history and physical exam, to diagnose the disease and recommend treatment. If positive for Haemophilus influenzae, local health officials might also want to run tests to figure out if the infection is due to type b or some other subtype. Physical Exam Before diagnosing Hib, healthcare providers will first take a medical history and ...

A 6-year-old boy is brought to the emergency department with increased work of breathing. His parents, who are at the bedside, recall that the patient developed a “stuffy nose” two days ago. This morning, he was noted to have a hoarse voice, drooling, and increased work of breathing. The patient was born full-term at home and has rarely seen a physician. Past medical history is otherwise noncontributory. Temperature is 39.4°C (103°F), Image reproduced from Radiopedia Which of the following best describes the medication that would have been most effective in preventing this patient’s current symptoms? Encapsulated strains are classified into six serotypes based on their capsular antigens - a, b, c, d, e and f, and unencapsulated strains are called nontypable, because they lack the polysaccharide capsule, and, consequently, capsular antigens. The strains that cause disease in humans are most often Now, And since it’s a coccobacillus, it’s shaped somewhere between round, like a coccus, and linear, like a bacillus. Finally, Another way to grow it is to grow it with On both blood agar and chocolate agar, So first, encapsulated strains of Sitemap USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names a...

Haemophilus Influenzae Infections in Children What is Haemophilus influenzae in children? Haemophilus influenzae (H. influenzae) is a group of bacteria that can cause different types of infections in babies and children. H. influenzae most often cause ear, eye, or sinus infections. They also cause pneumonia. A strain of the bacteria that causes more serious disease is called H. influenzae type b. The type b strain is now rare in the U.S. because of the Hib vaccine. Before widespread vaccination, significant disease occurred in as many as 130 out of 100,000 kids. That rate is now less than 1 out of 100,000 children. The type b strain caused many cases of infection of the membranes that surround the brain (meningitis). It also caused a life-threatening infection called epiglottitis. This is infection of the part of the throat that covers and protects the voice box and windpipe (trachea) during swallowing. In rare cases, a child may still get an H. influenzae type b infection. This is more likely to occur in a child who has not finished the series of vaccines. Or it can occur in an older child who did not get the vaccine as a baby. Children who travel to other countries may also be at risk. This is because not all children around the world get the Hib vaccine. Most cases of H. influenzae that occur today are due to the non-type b strains of the bacteria. What causes H. influenza in a child? The H. influenzae bacteria live in the nose, sinuses, and throat. They are often sprea...

Haemophilus influenzae, or H. influenzae, is a kind of bacteria. It can cause bacterial infections ranging from mild (such as bronchitis) to severe (such as septic arthritis). Symptoms depend on the specific. Treatment includes antibiotics but you may also require hospitalization depending on the severity of your condition. Overview What is Haemophilus influenzae? Haemophilus influenzae ( H. influenzae) is a type of bacteria that can cause several different kinds of infections. These bacterial infections can range from mild, such as Some H. influenzae infections are “invasive,” which means the bacteria invade parts of your body that are normally free from germs. For instance, H. influenzae can invade the fluid surrounding your spinal cord and brain, which can cause What is Haemophilus influenzae type b? Haemophilus influenzae bacteria are categorized into encapsulated (typeable) and non-encapsulated (non-typeable). Encapsulated means the bacteria have an outer protective covering. This covering, or capsule, makes them more resistant to The most common type of H. influenzae is Haemophilus influenzae type b (Hib). Most often, Hib affects children younger than 5 years of age and adults over 65 years of age. It can also affect people who have weakened • • No • Antibody or complement deficiency syndromes. • • People undergoing chemotherapy, radiation or who have had a The Does Haemophilus influenzae cause influenza? Despite its name, Haemophilus influenzae doesn’t cause the flu...