| The haemophilus species have 3 subgroups that are of clinical improtance, what are they | 1)H. influezae: causes meningitis, otitis media, cellulitis, pneuonia, epiglottitis and bronchitis
2)H. ducreyi: soft sore or chancroid
3)H aegyptius: conjunctivitis |
| the blood loving organism requires which factors to grow | factor X and V which are available on chocolate agar. |
| microscoptic features of H. influenzeA | gram neg coccobaccili: non sporin non motile. some starins posses polysaccharide capsule. 6 strains. a,b,c,d,e and f.
strain b (Hib) causes 95% of invasive disease |
| before introduction of vaccines, leading cause of bacterial meningitis and other invasive bacterial disease inchidren under 5 is? | Hib. The vaccine is Hib conjugate vaccine |
| mode of transmission | droplets discharge from upper resp tract. most common portal of entry is nasopharynx. |
| infectious period | as long as organism is present. non infectious within 24-48 hrs after start of antibiotics |
| reserviours | humans. children and adults are carriers |
| virulence factors of H influenzae | 1) capsular polusaccharide
2) lipopolysaccharide
3)IgA protease
4)pili |
| clinical presentationof H. influenzae | 1)meningitis: fever, headaches, stiffneck, photophobia, seizures and coma in infants, poor feeding and bulging fontanelle in chidren 2mths-2 years: mortality and neurological complications are high.
2) epiglottis: second most common infection of H. influenzae in children 3-18months. sudden onset sore throat and fever, shortness of breath, obstructied airways, difficulty to swallow. life threatening
3) pnemonia
4) celluitis
5) septic arthritis. |
| specimen for lab diagnosis of H. influenzae | specimen: csf and blood, nasopharyngeal swab, pus, sputum, aspirate from join and throat swab |
| Lab diagnosis of H. influenzae | 1)gram stain and culture on chocalte agar for factor X and V. satellitism with stap aureus.
2)capsular detection by quellung rxn or latex agglut. test.
3)slide agglut. test. |
| lab identification of H. influenzae | Gram neg coccobacilli. require factor X and V from chocolate agar. presence of 5-10% cO2 to enhance growth. cannot grow on nutrient agar.
catalase and oxidase pos.
satellitsim for S. aurus which acts as a source of factor V(NADP co enzyme)
FActor X is found in blood. |
| treatment of H. influnzae | 1) sulphonaides: trimethoprim-sulphamethoxazole
2) chloramphenicol
3) ciprofloxacin
4)ampicillin
5) cefotaxime
6) ceftazidime |
| preventation and control of H. influnzae | PRP vaccine, conjugate PRP antibiotic chomoprophylaxis with rifampin. |
| causative agent of soft sore or chancroid | H. ducreyi. |
| virulence factor of H, ducreyi | pilli, outer embrane protien |
| microscopic characteristics of H ducreyi | gram negative coccobaccili: shows bipolar staining. occurs in parrallel chains "school fish r rail road track"
grow on CAM- chorioallantonic membrane of live chick embryo
grow on chacolate agar with factor X but not V |
| treatment of H ducreyi | azithromycin, ceftrixone, cipro and tetracyclin |
| H. aegyptius causes highly infectious form of acute conjunctivitis, what are its microscopic characteristics? | gram negative bacillus: requires the same growth factor as H. influenzae( factor X and V on chocolate agar). thus sometimes called H. influeza biotypeIII. |
