Infectious (7)- Gomez Flashcards

Question

Mycobactericea

Answer 1

Part of the CMN group (corynebacteria, mycobacteria and nocardia) Contain polymer complex composed of peptidoglycan, arabinogalactan and mycolic acids Rod-like to filamentous Mycobacteria are gram ? [gram (+) due to cell wall structure vs gram (-) via DNA] Mycobacteria and nocardia are acid fast Use Ziehl-Neelsen stain for identification Cord factors - dimycolates of trehalose give rise to growth in serpentine cords M. tuberculosis complex: M. tuberculosis, M. bovis M. tuberculosis – tuberculosis (Spread by airborne droplets and can cause prolonged productive cough) M. bovis – oropharyngeal and intestinal tuberculosis via unpasteurized cow milk M. leprae - tuberculoid or lepromatous leprosy (Hansen disease) Nontuberculous mycobacteria

Answer 2

Primary Infection Ghon complex (parenchymal lesion & involved lymph node) Granulomatous response, usually asymptomatic and self-limiting but clinically symptomatic in 5% Secondary Infection Reactivation of old walled-off lesions, usually apical (high ppO2) Variable course: cavitary caseous necrosis with subsequent scarring or progressive disease Miliary TB occurs when tubercle erodes into a vessel In immunosuppressed may see TB without granulomas Dissemination in 10-15% of mildly immunosuppressed Dissemination in >50% of severely immunosuppressed Dx – PPD test, acid-fast stain on sputum, mycobacterial cultures Rx - Isoniazid, rifampin and ethambutol (drug resistance has emerged) Prevention - bacillus Calmette–Guérin (BCG) vaccine (will cause a positive PPD test)

Answer 3

Bronchopneumonia and Lobar pneumonia | Bronchopneumonia predominant type

Answer 4

A, Acute pneumonia. The congested septal capillaries and numerous intra-alveolar neutrophils are characteristic of early red hepatization. Fibrin nets have not yet formed. B, Early organization of intra-alveolar exudate, seen focally to be streaming through the pores of Kohn C, Advanced organizing pneumonia. The exudates have been converted to fibromyxoid masses rich in macrophages and fibroblasts.

Answer 5

Usually self limiting “chest cold” but can be lethal Often co-existing laryngobronchitis, bronchilolitis, tonsilitis Can be epidemic as in influenza pandemic 1918 (swine flu/H1N1) 40 MILLION dead (antigenic shift) (drift with minor neurominidase or hemagglutinin mutations and shifts with animal virus RNA recombination/replacement of both) Swine Flu – H1N1 and H3N2 influenza A June 11, 2009 pandemic H1N1 Bird Flu – Avian influenza A

Answer 6

ssRNA w envelope; viral RNA-dependent RNA polymerase; reproduce in nucleus One genus (influenza) and 3 types A, B and C Nucleoprotein antigen that determines the virus type (A, B or C) Envelope with surface glycoproteins hemagglutinin (H) and neuraminidase (N) Transmission is airborne and leads to acute respiratory disease aided by hemagglutinin attachment to respiratory mucosa Neuraminidase produces mucus liquefaction leading to local viral spread Can progress to pneumonia from initial URI 1.Antigenic drift - mutations in the RNA → minor changes in the antigenic character of H and N molecules 2.Antigenic shift - rearrangement of genome segments →major changes in the antigenic character of the H and N molecules 1957 Asian flu (H2N2), 1968 Hong Kong flu (H3N2), 1977 Russian flu (H1N1), 2009 swine flu (H1N1) [had partial protection in U.S. population due to H1NI swine flu outbreak in 1988 and 1977 Russian flu] Next pandemic? – possibly avian flu (1997 H5N1 or 32013 H7N9) CHILD + FLU (or chickenpox) + ASPIRIN → REYE SYNDROME Prevention: Yearly inactivated vaccines

Answer 7

``` ssRNA with envelope Parainfluenza Mumps Measles Respiratory syncytial virus Human metapneumovirus ```

Answer 8

Can cause common cold, bronchiolitis and pneumonia in children and adults

Answer 9

Local infection of ciliated respiratory epithelium Cause 30-40% of acute respiratory infections in infants and children Mild cold-like to life-threatening (croup, bronchiolitis, pneumonia) Most common cause of croup laryngotracheobronchitis (barking cough, steeple sign)

Answer 10

Paramyxovirus ; -ssRNA with envelope Local infection in ciliated epithelia (upper or lower respiratory tract), nose, eye and mouth Major cause of bronchiolitis and pneumonia in infants (#1 cause in age < 6 months) Severe disease may present as bronchiolitis, pneumonia or croup Reinfection in adults usually involves the upper respiratory tract (common cold) - Strongly suspect in infants with lower respiratory tract infection

Answer 11

Paramyxovirus ; -ssRNA with envelope Enters oropharynx from human secretions followed by viremia to skin, mucosae, CNS, lymphatic & respiratory systems Koplik spots of mouth precede T-cell mediated rash Usually have fever, maculopapular rash, +/- conjunctivitis that can lead to blindness, and sometimes pneumonia

Answer 12

Naked dsDNA with numerous serotypes Respiratory and oral-fecal transmission Acute respiratory disease – serotypes 4,7 &21) upper respiratory infections in kids/young adults that can progress to pneumonia Gastroenteritis - adenoviruses that lead to diarrhea Pharyngoconjunctivitis – pink eye and sore throat

Answer 13

small, naked +ssRNA Heparnavirus – discussed with hepatitis viruses Rhinoviruses (100 serotypes) Infection occurs person to person via the nasopharynx Attach via ICAM-1 receptor to respiratory epithelial cells Cause common cold

Answer 14

owl-eye basophilic intranuclear inclusions Transmission Transplacental - primary infection pregnant mother Neonatal - cervical or vaginal secretions during birth Perinatal -breast milk from a mother who has active infection Saliva – common during preschool years Genital - dominant mode after about 15 years of age ***Respiratory secretions

Answer 15

Severe acute respiratory syndrome (fever >100, flu symptoms) Severe acute atypical respiratory syndrome: a novel coronavirus 2002/3 – first cases in Asia spread globally Spread via respiratory droplets and can lead to ARDS

Answer 16

Middle East Respiratory Syndrome Coronavirus Asymptomatic to severe acute respiratory syndrome (fever and pneumonia) in person coming from Arabian peninsula or in close contact with MERS patient 2012 – first cases in Jordon and Saudi Arabia

Answer 17

``` Organisms Staphylococcus aureus, many gram-neg Mixed, including anaerobic organisms Bacteroides fragilis Fusobacterium Peptococcus ``` Other sources: #1 Aspiration, usually right lower lobe Neoplasia

Answer 18

Transcervical (Ascending) Infections Inhalation of infected amniotic fluid (in utero) or infected passing through infected birth canal Most bacterial, some viral (HSV II) Pneumonia, sepsis and meningitis common if infected via inhalation Transplacental (Hematologic) Infections Includes TORCH group of infections (Toxoplasma, Rubella, CMV, Herpes, Other, i.e. Treponema pallidum) Pneumonitis, encephalitis, chorioretinitis, myocarditis, dermatitis

Answer 19

Most common cause of bronchiolitis and pneumonia in children < 12 month Associated otitis media in many children F (fusion) protein on membrane induces multinucleate syncytia

Answer 20

``` Frequently a localized lesion in immunocompetent patients Many are granulomatous processes: Tuberculosis Leprosy Fungal ```

Answer 21

Primary Infection Ghon complex (parenchymal lesion & involved lymph node) Granulomatous response, usually asymptomatic and self-limiting but clinically symptomatic in 5% Secondary Infection Reactivation of old walled-off lesions, usually apical (high ppO2) Variable course: cavitary caseous necrosis with subsequent scarring or progressive disease Miliary TB occurs when tubercle erodes into a vessel In immunosuppressed may see TB without granulomas

Answer 22

Histoplasma capsulatum 3-5 microns (Ohio, Mss river), soil spores, bird and bat feces Blastomyces dermatidis 5-15 microns, Centerl and SE USA, Canada, mexico, middle east, africa, india], from soil spores Coccidioides immitus 50-60 microns, from southwest (san juaquin valley), far west and mexico. Soil spores

Answer 23

Can get all the “usual” organisms but more virulent behavior! (bacteria, TB, CD4>200) Common “unusual” diffuse pneumonias: pneumocystis jirovecii, CMV, mycobacterium avium Common "unusual" focal pneumonias: Aspergillus sp candida albicans Similar infections with immunocompromised patients with other conditions (chemotherapy, transplants, etc)

Answer 24

``` Used for end stage lung disease Emphysema Idiopathic pulmonary fibrosis Cystic fibrosis Idiopathic/familial pulmonary hypertension ``` Complications: Infections Acute rejection (mononuclear with few PMNs and Eos) Chronic rejection (bronchiolitis obliterans) EBV-associated lymphomas 79% 1 year/ 53% 5 year/ 30% 10 year survivals

Answer 25

Foamy "cotton candy" exudate and “cup and saucer”-shaped organisms

Answer 26

pseudohyphae and blastoconidia (budding yeast-- spaghetti and meatballs appearance

Infectious (7)- Gomez Flashcards

(50 cards)