pg1 Report on influenza – ethiology, epidermiology, pathogenesis, treatment Ethiology caused by influenza virus – orthomixoviridae family – 3 types A,B,C – single stranded RNA . 8 pieces. Influenza A has 2 main surface antigens – Haemaglutin (H) & Neuraminidase (NA). (H) responcible for cell attachment to host cell and agglutination of RBC further divided into H1,H2,H3. (NA) – Prevent self aggregation and promoting dispersion during budding of new virions from the infected cell. Responsible for receptor destruction. Divided into N1,N2. Epidermiology – transmitted by humans, thru respiratory droplets. IP – 6hrs 2day Antigenic shift – occurs when major change in antigenic type H2N2—H3N3 occurs due to new RNA segments and are the reason for major pandemics. Antigenic drift – relatively frequent minor changes in antigenic type H / N this is due to small mutations in RNA segments. Pathogenesis – Transmission via droplet inhalation – virus binds to respiratory epithelium – replication – cell death (Further NA decrease viscocity of mucos & damage of ciliary columnar epithelium – virus & exudative fluid go to lower respiratory tract causing complication of viral / bacterial mixed pneumonia.) clinical features younger childrencroup, bronchiolitis ,bronchitis, mild pneumonia. Older children, adolescents, adults I.B6hr2days(a) Fever(38.4C),headache, myalgia, chills, malaise (b)Respiratoydry cough,sore throat, nasal congestion. Trachitis (burning, itching, non productive cough) (c) ocular photophobia, tearing, conjunctivitis.(d)meningismus (intoxication) (e) petechias in skin mucus, visaral organs Complications 1. pneumonia viral/ bacterial. H.influansa, staph. aureus, Step pneumonia 2. Reyes syndrome has occurred in 210 yrs old children who have use Asprine (1) sudden onset of nausea, vomiting for 12 days followed by neurological symptoms lethargy, confusion, coma (2) hepatomegaly, ALAT, ASAT, LDH increased. bilirubinN no jaundice (3)blood ammonia ,hypoglycaemia (4) liver biopsy fatty infiltration of hepatocytes (5) CNS cerebral oedema CSF P increased indicate encephalopathy (death due to increased intercranial pressure) (Other conditions that lead to Reyes chicken pox ,EBV, entero) 3.Myositis 4. Myocarditis 5 Guillain barre syndrom –can happen a/f any viral infection, allergie or autoimmune reaction to virus Clinics (1)febrile stagefever headache, body aches (2) latent stage symp. disappar and is normal for 14wk (3) paralytic stageacute severe weakness or paralysis starting from LL goes to trunk – respiratory m. UL weakness more in proximal than distal m. , cranial VII,X involment leading to facial paralysis. Diagnosis – throat swab – RIA, ELISA, haemagglutination inhibition, compliment fixation. Blood test (double antibody test) 1st antibody test 7 days after 1st symptom, 2nd antibody test 1014 days If titer >x4. (+)Blood test – if bacteria complicated increased ESR , leucocytosis if only influenza – leucopenia , relative lymphocytosis ,sputum for smear grams stainexamine for leucocytes & bac. Treatment – Ethiological –Amantadine, Remantadine 1st day 300mg, 2nd day 200mg, 3rd day 100mg (1 tab 50mg)mostly for A. Pathological –glucose vit –C.SymptamaticAnalgertics,Antipyretics(declofenac) .Relanza(for influA B) two to 4 sprays –3 days. Profilaxis 1.vaccination yearly b/c antigenic shift occurs these are only against A&B.2. Remantadine 50mg(1 tab day)for 5days vac. is given to all risk patients. Dif/ Dig of infuenza 1.All other virus infec.2. T.B.C 3.Classic bac.phemonia. 4. Urogenital infc. 5. Viral hepatitis A 6. malaria 7.dangue 8.sepsis 9.E.B.V Complication –phumonia Viral pheumonia 1st day develop/Can be cough with blood,tachypnoea,resp. insufficacy/ diffuse bilateral /Therapy Remantadine,Amantadine,Relanza Bac. Pheumoia
Deve.later 7 day/ sputum with pus / unilateral lobar / Therapy Remantadien –3days /Amoxicilln ,amoxiclar 7days or 714 days
Report on influenza – ethiology, epidermiology, pathogenesis, treatment Report prepared by 1. Dr. Sajid Mahmood, MD (EU), Accident & Emergency Department, NHS Royal infirmary Liverpool United Kingdom. 2. Dr. Adnan Akram, MD (EU), Department of Infectious Diseases. University Hospital Riga Latvia. 3. Dr. Aftab Ahmed, MD (EU), Infection Control Department, Kaunas Medical University Clinic. Lithuania. Contact: publications [at] infekcijas.eu