Infection Summary Flashcards

1
Q

Gastroenteritis Presentation

A

vomiting and diarrhoea (3 or more loose stools a day), + abdominal pain/discomfort (can be quite severe if campylobacter), fever,

bloods in stool can be indicative of a bacterial infection

signs of dehydration:

thirsty, dry mucous membranes: mild, (<5% weight loss)

lethargic, reduced skin turgor, sunken eyes, sunken anterior fontanelle, tachycardia, reduced urine output, reduced tears: moderate (5-10% weight loss)

drowsy, absent urine output, prolonged capillary refill time, weak pulse, low BP (signs of hypovolaemic shock): severe (>10% weight loss)

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2
Q

Gastroenteritis Investigation / diagnosis

A

stool MC&S, urea and electrolytes

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3
Q

Gastroenteritis Management

A

oral rehydration therapy given frequently in small amounts; IV fluids if not tolerating oral/nasogastric fluids. Good handwashing to prevent spread. Notify public health if bacterial

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4
Q

Complications of campylobacter infection

A

Guillain-Barre

Reactive arthritis

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5
Q

What can predispose you to gastroenteritis?

A

HIV

Omeprazole

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6
Q

Presentation of CDIFF

A

mild diarrhoea to severe colitis

diarrhoea, fever, abdominal pain

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7
Q

Investigations for CDIFF

A

stools MC&S, FBC (increased WCC)

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8
Q

Treatment for C. Diff

A

metronidazole (first line), stool transplant, oral vancomycin (second line), fidaxomicin, surgery may be required, isolation, barrier nursing

prevention: stop AB (cephalosporin, clarithromycin, clindamycin, co-amoxiclav) (fluoroquinolones are also important in the development of c.diff)

Pass medicine note: Clindamycin is historically associated with causing Clostridium difficile but the aetiology has evolved significantly over the past 10 years. Second and third generation cephalosporins are now the leading cause of Clostridium difficile.

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9
Q

What are the complications of C.Diff?

A

pseudomembranous colitis, toxic megacolon, sepsis

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10
Q

What are the toxins that c.diff produces?

A

A (enterotoxin) and B (cytotoxin)

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11
Q

Presentation of infectious diarrhoea

A

fever, diarrhoea (may be bloody), nausea, dehydration, abdominal pain, bloody diarrhoea is more common with Campylobacter, Shigella

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12
Q

What is the diagnosis of infectious diarrhoea?

A

diagnosis by antigen detection

FBC, U&E, CRP, stool microscopy, culture and sensitivity (MC&S), blood cultures if septic

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13
Q

What is the management of infectious diarrhoea?

A

majority of cases are self-terminating and require rehydration and electrolyte correction: AB are considered in immunocompromised patients, the very young or the very septic; always liaise with microbiologists

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14
Q

What viruses can cause infectious diarrhoea?

A

adenovirus, rotavirus in children under 5 years

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15
Q

What are the complications of infectous diarrhoea?

A

renal failure, septic shock; E. coli is associated with the haemolytic-uraemic syndrome

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16
Q

What are the symptoms / presentation for giardia lamblia?

A

diarrhoea, malabsorption, failure to thrive

Giardiasis:

a patient develops persistent foul-smelling watery diarrhoea and weight loss after travelling to India. His symptoms have now lasted two weeks. He has no abdominal pain, nausea or fever

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17
Q

What is the investagation for giardia lamblia?

A

Cysts seen on stool microscopy

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18
Q

What is the treatment for giardia lamblia?

A

Metronidazole

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19
Q

How is giardia lamblia spread?

A

Contaminated water

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20
Q

Whet type of organism is giardia lamblia?

A

Parasite

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21
Q

What bacterium causes the majority of cases of travellers diarrhoea in developing countries?

A

Enterotoxigenic e.coli

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22
Q

What is the normal reservoir of Ecoli o157 (this is an enterohaemorrhagic bacterium)

A

2.5% of britich cattle secrete VTEC (verotoxin producing Ecoli)

The reservoir of infectio nis in the gut of herbivores.

The organism has an ectremely low infecting dose.

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23
Q

What are the symptoms of enterohaemorrhagi bacteria?

A

Initial watery diarrhoea

Becomes blood stained in 70% of cases. Associated with severe and often constant abdominal pain.

Little systemic upset, vomittin or fever.

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24
Q

What is the complication associated with Ecoli o157?

A

HUS

Haemolytic Uraemic syndrome

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25
Who is affected by HUS?
HUS affects 10-15% of sufferers from this infection Arises 5-7 days after the onset of symptoms Most likely i nthe extremes of age, heralded by a high peripheral leucocyte count and may be induced particularly in chgildren by antibiotic therapy
26
What is the treatment for HUS?
Dialysis if necessary and may be averted by plasma exchange Antibiotics should be avoided since they can stimulate toxin release.
27
What cells does the HIV virus attack?
Attacks the CD4 cells (T helper cells, macrophages and dendritic cells)
28
What are the features of the primary infection of HIV?
Usually symptomatic in more than 50% of cases Incubation period is 2-4 weeks after exposure Clinical features resemble a glandular fever type of illness (flu like symptoms - (presence of maculopapular rash and oral ulceration strongly suggests primary HIV infection rather than other viral casues of glandular fever.)
29
What is the progression of HIV after the primary infection?
Chronic phase which can last 2-10 years. Depletion of CD4 cells and increase viral load Clinical latelcy follows primary infection - individuals are asymptomatic. Persistent lymphadenopathy less than 2cm diameter ius a common finding.
30
What is the differential diagnosis for primary HIV?
EBV Primary cytomegalovirus infection Rubella Primary toxoplasmosis Secondary syphilis
31
When does HIV become AIDS?
The development of specified opportunistic infections cancers and severe manifestations of HIV itself. Can be diagnosed by having a CD4 count that is less than 200/mm3 CDC is the most used category of AIDS defining illnesses
32
CDC category A for HIV
Primary HIV infection Asymptomatic Persistent generalised lymphadenopathy
33
CDC category B for HIV
Candidiasis (oropharyngeal) Fever / diarrhoea lasting for over one month Oral hairy leucoplakia Cervial dysplasia / carcinoma in situ Idiopathic thrombocytopenic purpura Peripheral neurupathy
34
CDC category C for HIV infection
Candidiasis of trachea, bronchi or lungs Cervical carcinoma that is invasive Cryptococcosis - extrapulmonary Cytomegalovirus disease (outside the liver spleen and nodes) Herpes simplex chronic ulcers or visceral HIV encephalopathy Kaposi's sarcoma Lymphoma (cerebral or B cell non hodgkin) Pneumocystis pneumonia Recurrent bacterial pneumonia Cerebral toxoplasmosis Tuberculosis
35
How is viral load determined?
Quantitive PCR of HIV - RNA
36
How is HIV diagnosed?
By detectiong host antibodies (either by point of care tests or by ELISA) A positive antibody test from two different immunoasays is sufficiennt to confirm infection Screening may involve testing for p24 antigen in addition to antibodies (incase antibody production hasn't started yet) Nucleic acid amplification (usually PCR) of HIV-RNA is carried out on children who's mothers have had AIDS (the maternal antibodies will live in their system for 15 months and they might not have produced their own antibodies yet).
37
What are the aims of ART?
Reduce the viral load to an undetectable level for as long as possible Improve CD4 count to over 200 cells/mm3 so that severe HIV-related disease is unlikely Improve the quality of life without unacceptable drug toxicity Reduce HIV transmission
38
What are the classes of antiretroviral drugs?
Nucleoside reverse transcriptase inhibitors (NRTIs) Non-nucleoside reverse transcriptase inhibitors (NNRIS) Protease inhibitors Integrase inhibitors Chemokine receptor inhibitor
39
Give examples for each type of ART
NRTI - abacavir, zidovudine NNRTI - Efavirenz PI - Atazanavir Integrase inhibitors = Raltegravir Chemokine receptor inhibitor = maraviroc
40
What is the standard antiretroviral regimen?
Two NRTI's together NNRTI Protease inhibitor or Integrase inhibitor Most guidelines from high-income countries allow clonicians to choose a starting regimen of dual NRTIs combined with an NNRTI, or a PI or integrase inhibitor as these three regimens have a similar efficacy.
41
What must PI's be co-prescribed with?
Must be co-prescribed with ritonavir - low doses oof ritonavir dramatically increase the concentrations and elimination half-lives of other PI's by inhibitin gtheir metabolism by cytochroime P450. This increases drug exposure, reducing pill burden and dosing frequency - optimising adherence
42
When should ART therapy begin?
Following the 2015 BHIVA guidelines it is now recommended that patients start HAART as soon as they have been diagnosed with HIV, rather than waiting until a particular CD4 count, as was previously advocated.
43
Lymes Disease Presentation:
early: erythema chronicum migrans + systemic features (fever, arthralgia) CVS: heart block, myocarditis neuro: cranial nerve palsies, meningitis
44
What causes Lymes disease
Spirochaete Borrelia Burgdorferi
45
What is the investigation for Lymes disease?
NICE recommend that Lyme disease can be diagnosed clinically if erythema migrans is present enzyme-linked immunosorbent assay (ELISA) antibodies to Borrelia burgdorferi are the first-line test if this test is positive or equivocal then an immunoblot test for Lyme disease should be done
46
What are later complications of Lyme Disease?
Acrodermatitis chronica atroficans (ACA) - this is atrophy of the skin, often has involvement of the peripheral nervous system causing polyneuropathy Lymphocytoma can also be caused (also chronic) neuroborreliosis
47
What is the management of asymptomatic tick bites?
tick bites can be a relatively common presentation to GP practices, and can cause significant anxiety NICE guidance does not recommend routine antibiotic treatment to patients who've suffered a tick bite
48
What is the management of Lymes disease?
Management of suspected/confirmed Lyme disease ## Footnote doxycycline if early disease. Amoxicillin is an alternative if doxycycline is contraindicated (e.g. pregnancy) ceftriaxone if disseminated disease Jarisch-Herxheimer reaction is sometimes seen after initiating therapy: fever, rash, tachycardia after first dose of antibiotic (more commonly seen in syphilis, another spirochaetal disease)
49
What type of virus is Rabies?
RNA rhabdovirus (specifically a lyssavirus)
50
What are the features of Rabies?
prodrome: headache, fever, agitation hydrophobia: water-provoking muscle spasms hypersalivation Negri bodies: cytoplasmic inclusion bodies found in infected neurons
51
What is the treatment for Rabies?
There is now considered to be 'no risk' of developing rabies following an animal bite in the UK and the majority of developed countries. Following an animal bite in at-risk countries: ## Footnote the wound should be washed if an individual is already immunised then 2 further doses of vaccine should be given if not previously immunised then human rabies immunoglobulin (HRIG) should be given along with a full course of vaccination. If possible, the dose should be administered locally around the wound
52
What is the diagnostic test for rabies?
PCR to check for lyssavirus in the CSF
53
What is rat fever?
Leptospirosis
54
What are the clinical features of Influenza
2-4 days incubation period (1-7) temperature up to 41° (38-40) for 3 days (1-5), 2 of the following: cough (sore throat, rhinorrhoea), myalgia, headache, malaise. Predominance of systemic symptoms. Less common symptoms include tiredness, chills, headache, sore throat, runny nose, sneezing, nausea, vomiting, diarrhoea, loss of appetite, aching muscles, limb or joint pain
55
What is the treatment for influenza?
influenza A or B, both for treatment or prophylaxis, start within 48 hours of onset of symptoms/contact: oseltamivir, zanamivir
56
What are the complications of influenza?
common: RESP: acute bronchitis, secondary bacterial pneumonia less common: RESP: primary viral pneumonia, CV: myocarditis/pericarditis, CNS: transverse myelitis/ Guillain Barre, myositis & myoglobinuria
57
What is tha pathogen associated with bronchiolitis?
RSV (respiratory syncytial virus) (75-80% of cases) Mycoplasma and adenoviruses are also causes
58
Who often gets bronchioloitis?
Babies less than 1 years old = peak incidence is 3-6months Maternal IgG protects gainst RSV More common in winter
59
When is bronchiolitis more serious?
When there is bronchopulmonary dysplasia in premature babies CF Congenital heart disease
60
What are the features of bronchiolitis?
coryzal symptoms (including mild fever) precede: dry cough increasing breathlessness wheezing, fine inspiratory crackles (not always present) feeding difficulties associated with increasing dyspnoea are often the reason for hospital admission
61
When do NICE recommend immediate referral whenm there is a case of bronchiolitis?
apnoea (observed or reported) child looks seriously unwell to a healthcare professional severe respiratory distress, for example grunting, marked chest recession, or a respiratory rate of over 70 breaths/minute central cyanosis persistent oxygen saturation of less than 92% when breathing air.
62
When should clinicians refer to th hospital if there is a case of bronchiolitis according to NICE?
a respiratory rate of over 60 breaths/minute difficulty with breastfeeding or inadequate oral fluid intake (50-75% of usual volume 'taking account of risk factors and using clinical judgement') clinical dehydration.
63
What are the investigations for bronchiolitis?
immunofluorescence of nasopharyngeal secretions may show RSV CXR: may show hyperinflation/patchy infiltrative change
64
What is management for bronchiolitis?
Largely supportive humidified oxygen is given via a head box and is typically recommended if the oxygen saturations are persistently \< 92% nasogastric feeding may be need if children cannot take enough fluid/feed by mouth suction is sometimes used for excessive upper airway secretions CPAP/ ventilation if severe Ipratropium inhalers may help Palivizumab (monoclonal Ab) given monthly as primary prophylaxis during RSV season to at-risk infants (ie: chronic lung disease, congenital heart disease)
65
What are the complications of bronchiolitis?
chronic wheeze, bronchiolitis obliterans (adenovirus)
66
What organism causes amoebic dysentry?
Entamobea Histolytica
67
What organism is most likely to cause invasive pulmonary aspergillosis?
A. fumigatus
68
What are the risk factors for invasive aspergillosis?
Neutropenia Solid organ or allogenic stem cell ttransplant Corticosteroids Leukaemia and other haemotological malignancies Cytotoxic chemotherapy Advanced HIV disease Severe COPD Critically ill patients on intensive care units Chronic granulomatous disease
69
What are the findings on CT that would indicate invasive pulmonary aspergillosis?
Dense, well circumscribed lesions with or without a halo sign Air crescent sign Cavity
70
When is an immunocompromised patient heavily suspected of having invasive pulmonary aspergillosis?
If they develop fever, new resp symptoms, (particularly pleural pain or haemoptysis) or a pleural rub.
71
What are the features of tracheobronchial aspergillosis?
Involvement is characterised by the formation of fungal plaques and ulceration
72
What are mycological ways to diagnose aspergillosis?
Using sputum, BAL fluid or bronchial brush to find one of the following: Fungal elements indicating mould of aspergillus Culturing a mould of aspergillosus
73
What blood test can be done to look for invasive pulmonary aspergillosis?
Detection of aspergillus cell wall components (galactomannan and B-1,2-glucan) in blood or BAL fluid and aspergillus DNA by PCR.)
74
What is treatment choice for invasive pulmonary aspergillosis?
Voriconazole Second line agents include liposomal amphotericin, caspofungin or posaconazole.
75
What is sub-acute or chronic pulmonary aspergillosis?
Non-invasive complication of chronic lung disease such as COPD, TB, opportunistic mycobacterial disease or fibrotic lung disease
76
What disease does chronic pulmonary aspergillosis closely mimic?
TB
77
What are the features of chronic pulmonary aspergillosis?
Cough (with or without haemoptysis), weight loss, anorexia and fatigue over months or years Associated fever, night sweats and elevated inflammatory markers
78
What are radiological features of chronic or subacute pulmonary aspergillosis?
Thick walled - cavities (predominantly apical) Pulmonary infiltrates Pleural thickening and later fibrosis
79
What are the three different dsecriptive names of chronic pulmonary aspergillosis?
CNPA (chronic necrotising) Cavitatory Fibrosing
80
What are the features of malaria?
fever rigors aching bones adbo pain headache dysuria frequency sore throat cough fatigue myalgia nausea vomiting Signs: none, splenomegaly, hepatomegaly, mild jaundice, anaemia, tachycardia
81
What are the investigations for malaria?
thick and thin blood films (Giemsa, Field’s stain) schizonts on a blood film quantitative buffy coat (QBC) - this is a fluorescence microscopy based malaria diagnostice test rapid antigen tests (OptiMal and parasight F) FBC (anaemia), raised ESR, raised CRP, U&E, LFT
82
What are the organisms that cause malaria?
Plasmodium falciparum Plasmodium vivax Plasmodium ovale Plasmodium malariae Plasmodium falciparum causes nearly all episodes of severe malaria. The other three types, of which Plasmodium vivax is the most common, cause 'benign' malaria
83
What are protective factors for malaria?
G6PD deficiency HLA-B53 absence of Duffy antigens Sickle cell anaemia
84
What are the features of severe malaria?
schizonts on a blood film parasitaemia \> 2% hypoglycaemia acidosis temperature \> 39 °C severe anaemia complications as below
85
What are the complications of malaria?
Complications * cerebral malaria: seizures, coma * acute renal failure: blackwater fever, secondary to intravascular haemolysis, mechanism unknown * acute respiratory distress syndrome (ARDS) * hypoglycaemia * disseminated intravascular coagulation (DIC)
86
What might make you more likely to suffer from malaria?
Pregnancy Previous splenectomy
87
What is the result of parasitisation of the maternal side of the placenta?
IUGR Abortion
88
What are preventative measures for malaria?
awareness of risk per geographical area, bite prevention (cover up at dawn and dusk, insect repellent sprays, lotions, mosquito coils, permethrin-impregnated mosquito nets) chemoprophylaxis (malarone daily, doxycyline daily, mefloquine weekly, chloriquine weekly + proquanil daily diagnosis & treatment)
89
What is the management of malaria?
Artemisinin treatment is recommended Co-artemether (CoArtem or Riamet) contains artemether and lumefantrine - this is given as 4 pills, 6 times over 60 hours OR Quinine for 7 days plus doxycycline/clindamycin 7 days OR Malarone for 3 days
90
What is the treatment for severe or complicated malaria?
Severe malaria should be considered in any on-immune patient with aparasite count greater than 2% - medical emergency Antimalarial chemotherapy Correction of fluid, electrolytes, acid base balance IV artesunate IV quinine + oral doxycyline (or clindamycine) switch to oral treatments when patient is stable and can swallow
91
What is a side effect of quinine?
Dysrhythmias
92
What are the treatments for other forms of malaria?
treatment of other species of malaria chloroquine riamet add primaquine to eradicate liver hypnozoites this is in P vivax and P ovale (check for G6PD def - haemolysis may develop)
93
Which cells do neutrophils target?
Bacterial and fungal infection
94
Which cells do monocytes target?
Fungal infections
95
Which type of cells do Eosinophils target?
Parasites
96
What type of cell do T cells target?
Fungal and viral ifnection PJP
97
What type of cells do B lymphocytes target?
Bacterial inefection
98
What is the presentation of sepsis?
a high temperature (fever) or low body temperature chills and shivering a fast heartbeat fast breathing In the very young and the very old you can get low temperature. Potential for hyperglycaemia.
99
What is the presentation for septic shock?
feeling dizzy or faint **a change in mental state – such as confusion or disorientation** **diarrhoea** nausea and vomiting **slurred speech** severe muscle pain **severe breathlessness** less urine production than normal – for example, not urinating for a day cold, clammy and pale or mottled skin **loss of consciousness**
100
What are the tests for sepsis?
Temperature Breathing rate Heart rate Blood test (blood culture, FBC, lactate levels, increased levels can indicate organ dysfunction, CRP, procalcitonin – marker sometimes used to distinguish bacterial sepsis from other inflammatory conditions that cause similar symptoms Renal profile Liver function tests CSF analysis (meningitis)
101
What is the treatment for sepsis?
Broad-spectrum antimicrobials are usually given intravenously (IV). Drug therapy may be changed to a more targeted therapy once the microorganism causing the sepsis is identified. IV fluids are given to help improve and stabilise blood pressure. Sometimes medications are given to constrict blood vessels and increase blood pressure. Supplemental oxygen may be necessary, and some people require mechanical ventilation to assist with breathing. Other organ support, such as kidney dialysis, is sometimes necessary when organs start to fail. Surgical procedures are sometimes necessary to remove medical devices such as catheters that may be the source of the infection, to drain abscesses or fluids, to remove and/or fix damaged tissue, and to remove blockages.
102
What is the sepsis 6?
Sepsis 6 (three treatments and three tests) Treatment: Giving antibiotics Give IV fluids Giving oxygen Tests: Taking blood cultures (assess the cause of the sepsis) Taking a blood sample (this is used to assess the severity of the sepsis) Monitoring urine output (assesses the severity of the kidney function)
103
How do you maintain MAP in sepsis?
Vasopressors such as norepinephrine
104
What is included in the QSOFA?
Hypotension (systolic blood pressure less than 100mmHg) Altered mental status RR greater than 22/min Score greater than 2 suggests a greater risk of poor outcomes
105
What are the clinical features of typhoid?
1st week: fever, headache, abdo discomfort, constipation, dry cough, relative bradycardia, neutrophilia, confusion 2nd week: fever peaks at 7-10 days, Rose spots, diarrhoea begins, tachycardia, neutropenia 3rd week (complications): intestinal bleeding, perforation, peritonism, metastatic infections week 4 (recovery): 10-15% relapse
106
What are the investigations for typhoid fever?
Culture blood Urine Stool culture Bone marrow
107
What is the treatment for typhoid fever?
Oral azithromycin IV ceftriaxone Ciproflaxin FLuids
108
What are the causative organisms for thyphoid fever?
Salmonella typhi and paratyphi
109
How is typhoid transmitted?
faecal-oral transmission via contaminated food or water, preventable by vaccination
110
Symptoms of schistomiasis
1st few hours: swimmers itch (clears 24-48hrs) after 24h: invasive stage (cough, abdo discomfort, splenomegaly, eosinophilia) after 15-20 days: Katayama fever (protsrate, fever, urticaria, lymphadenopathy, splenomegaly, diarrhoea, eosinophilia 6-8 weeks: acute disease (eggs deposited in bowel (dysentry) or bladder (haematuria) chronic disease
111
What are the investigations for schistosomiasis?
Ab tests, ova in stools and urine, rectal snip
112
What is the management of schistosomiasis?
praziquantel prednisolone if severe
113
What are the complications of schistosomiasis?
squamous cell carcinoma (which is very rare except in tropical countries)
114
What animal spreads schistosomiasis?
Fresh water snail
115
Which highly infective skin condition is classicaly described as having a golden crust?
Impetigo
116
What organisms cause impetigo?
Staph aureus Less commonly strep pyogenes
117
What organism is most likely to cause erysipelas?
Mostly due to strep pyogenes
118
What is the key difference between cellulitits and erysipelas?
Erysipelas has distinct elevated borders whereas cellulitis doesn't
119
What systemic symptoms might be apparent for cellulitits and erysipelas?
Associated fever Associated lymphadenopathy and lymphangitis
120
What is the treatment for erysipelas and cellulitis?
Erysipelas: ## Footnote combination of anti-staphylococcal and anti-streptococcal AB in extensive disease, admission for IV AB and rest Cellulitis = (penicillin and flucloxacillin)
121
Necrotising fasciitis presentation:
extensive oedema and severe, unremitting pain systemic features include fever, hypotension, tachycardia, delirium, multiorgan failure, erythema +/- vesicle formation anaesthesia at site of infection is highly suggestive of this disease Type 1 = mixed aerobic and anaerobic infection, diabetic foot infection, fournier's gangrene Type 2 = monomicrobial initially similiar to cellulitis, septic, rapidly advancing erythema +/- painless ulcers
122
What are the investigations?
bloods (high WCC, low sodium), CT
123
What is therapy for necrotising fasciitis?
one of the infectious diseases emergencies. Surgical review is mandatory **AB should be broad spectrum (flucloxacillin, gentamicin, clindamycin)** intensive therapy unit (ITU), broad spectrum AB, bold surgical resection down to healthy tissue - reassess daily
124
What is the aetiology of necrotising fasciitis?
usually polymicrobial infection, typical organisms include strep, staph, enterococci, gram -ve bacilli, clostridium normally associated with **Strep pyogenes** can get it from infected needles, abscesses, open fractures, surgery or idiopathic
125
What are bacterial causes of meningitis?
Neisseria meningitidis (meningococcus) Strep pneumoniae (pneumococcus) In neonates E.Coli, group B strep (strep agalactiae is an example)
126
What are viral causes of meningitis?
Enteroviruses: - Echoviruses - Paraechoviruses - Coxsackie A and B viruses - Poliovirus (not seen in the UK) Mumps, now very rare due to the MMR vaccine HSV
127
What are less common causes of meningitis?
Haemophilus influenze type b Listeria monocytogenes Mycobacterium TB varicella z EBV
128
What type of organism is responsible for almost half of meningitis associated with ventriculo-atrial / peritoneal shunts?
Coagulase negative staph (eg staph epidermis)
129
What can cause non-infective meningitis?
Tumour cells in the CSF Reactions to certain drugs or chemicals or by some disease of unknown aetiology such as sarcoidosis or SLE SAH Migraine
130
What is the classical presentation for bacterial meningitis?
Headache Photophobia Neck stiffness Vomitting Fever Clouding of consciousness Cranial nerve palsies may occur (6,7,8)
131
What rash is associated with meningococcal meningitis?
Vasculitis Macular/maculo-papular, purpuric, pruritic or vesicular All occur due to meningococci or other meningitides
132
What would papilloedema suggest when examining someone for meningitis?
Unusual in meningitis and should lead one to consider an intracranial space occupying lesion
133
What are the clinical signs you can elicit in meningism?
134
What are investigations for meningitis?
Blood culture Lumbar puncture (if papilloedema then you should request a head CT to rule out a space occupying lesion, LP is contraindicated if this is the case)
135
What do microbiology do with CSF for meningitis?
Gram stain (and ZN if appropriate) Differential cell count (neutrophil polymorphs or lymphocytes) Antigen detection test (latex agglutination) Bacterial culture Mycobacterial or fungal culture (if appropriate) PCR for viruses (if appropriate) PCR for bacteria (if appropriate)
136
WHat is CSF biochemistry for meningitis?
Glucose (check serum level at the same time) Protein
137
What is FBC results in bacterial meningitis?
Neutrophil leucocytosis Leucopenia (septicaemia with DIC, you would also see, low platelets, abnormal clotting and increased fibrin degradation products)
138
After centrifugation what colour is the supernatant in the case of a SAH?
Golden yellow - due to haemoglobin breakdown Described as xanthochromic Bloody tape after centrifugation should have no xanthochromia
139
The daddy Appearance Cells Predominant cell type Glucose Protein For: Normal Bacterial meningitis Viral meningitis Tuberculosis meningitis
140
What are the principles of treatment for meningitis?
1. Early clinical recognition. 2. Rapid detection of pathogen. 3. Rapid initiation of appropriate bactericidal antimicrobial therapy. 4. Early recognition and treatment of sequelae of septicaemia (eg, DIC with shock, hypoxia, acidosis and adrenal insufficiency). 5. Antibiotic prophylaxis (when appropriate) of close contacts.
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What are possible antibiotic therapies in meningitis?
Benzyl penicillin Ceftriaxone
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What is the tumblr test?
Purpuric rash of meningococcal disease does not blanche under pressure
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What antibiotics are given on discharge after being treated for meningococcal meningitis?
Rifampicin or ciprofloxacin (adults only) This is to eradicate carriage of N. meningitidis from the nasopharynx
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WHo should be notified after confimation of meningococcal meningitis?
Local consultant in health protection They will coordinate the arrangements for prophylaxis
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What is the most frequent causative organism of bacterial meningitis in adults?
Strep pneumoniae
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Who is normally affected by neisseria meningitidis?
Primarily a disease of children and young adults Less than 10% of cases occur over the age of 5
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What are the features of strep pneumoniae?
Gram positive Diplococci alpha haemolytic on blood agar
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What can predispose to strep pneumoniae?
Pneumonia SInusitis Endocarditis Head trauma Alcoholism Splenectomy
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What is a key sign of s. pneumoniae meningitis?
Patient is more likley to have altered conscious level or focal neurological signs than those with haemophilus or meningococcal meningitis
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What is the treatment of S.pneumoniae meningitis?
High dose ceftriaxone
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What are the complications of s.pneumoniae meningitis?
Loss of hearing Cranial nerve deficits Hemiparesis Hydrocephalus Seizures
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What vaccine might help prevent s.pneumoniae meningitis?
pneumovax - for all those over 65 years old There is a conjugated version for those under 2 years (prevenar)
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Which HSV type complicates a primary genital herpes infectino with viral meningitis?
Type 2
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What is the presentation of viral meningitis?
Non-specific prodromal illness Rapid onset headache Photophobia Low grade fever Stiff neck Patient is usuall ylucid and alert, if encephalitis is also present then lethargy, confusion, seizures and focal neurological signs occur. With enteroviral meningitis, a rash may be present which, if petechial, may resemble menincococcaemia. With mumps meningitis, 50% do not have detectable parotitis.
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What are the investigations for viral meningitis?
PCR of CSF PCR of throat swabs and faecal samples
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What is the therapy for viral hepatitis?
Enteroviruses and Parechoviruses: This is symptomatic and recovery usually occurs within 72 hours. If chronic infection occurs (e.g. patient immunocompromised), treatment with intravenous immunoglobulin may be required. Herpes simplex virus: aciclovir, initially intravenously.
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When should the MMR vaccination be given?
12-13 months 3 years 4 months - 5 years
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What is the most important cause of meningitis in patients with HIV infection?
cryptococcus neoformans It also occures rarely in patients with diabetes, lymphoma and those receiving immunosuppressive drugs. The organism is found in bird dropssings, especially those found in pigeons.
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Which type of stain allows the capsule to be visualised as a clear zone around the yeast cell?
India Ink
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What are the investiations for cryptococcal meningitis?
Culture
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What are the symptoms of fungal meningitis?
Most commonly, there is a subacute onset of symptoms with low grade fever, headache, nausea, lethargy, confusion and abdominal pain. Meningism is less common, although it can develop quickly as the condition progresses.
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What is the treatment for cryptococcus neoformans meningitis?
Parental amphotericin (sometimes used in combination with flucytosine) High dise fluconazole is being increasingly used as an alternative to this combination Long term chemoprophylaxis with fluconazole is now given to patients with HIV infection following an episode of cryptococcal meningitis (secondary prophylaxis).
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How des neonatal meningitis differ from adult meningitis?
Symptoms and signs are not specific or not well localised ## Footnote The bacteria commonly involved are group B streptococci, E. coli and L. monocytogenes as well as enteroviruses and parechoviruses. Predisposing conditions include low birth weight, prolonged rupture of membranes and maternal diabetes mellitus.
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What are tje two clinical syndromes assocaited with neonatal meningitis?
Early onset - within 3 days of birth and associated with **prematurity** or a difficult or **prolonged** birth. Marked **respiratory distress**, bacteraemia and a high mortality (50%) are typical. The organism has usually been acquired at birth from the mother’s genital tract. Late onset - more than one week after birth. The infection is typified by bacteraemia and meningitis but pulmonary involvement is rare. Mortality is 10-20%. The organism may have been spread by cross-infection from other mothers, babies or healthcare workers.
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How is the daignosis made of neonatal meningitis?
Bacterial: Neonatal CSF and blood cultures are central to making the diagnosis. Maternal blood cultures and cultures of specimens from the genital tract may also be helpful. Viral: Neonatal CSF, EDTA blood, faeces and nasopharyngeal secretions.
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What is the treatment for neonatal meningitis?
``` Parenteral ampicillin (to cover group B streptococci and Listeria) and gentamicin or cefotaxime (to cover the gram negative bacilli) are used in combination, until the causative organism is identified. IVIG may be appropriate for enteroviruses or parechoviruses. ```
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What ways can we prevent neonatal meningitis?
Chemoprophylaxis to prevent neonatal group B strep infectionis given to high risk mothers during labour (usually amoxicillin or co-amoxiclav)
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What are the clinical features of HAV?
Fever Malaise Anorexia Nausea Vomitting Upper abdominal pain Jaundice developing 3-10 days later, during which time the urine may be dark becasue of the presence of conjugated bilirubin.
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What is the route of infection for hep A?
Faecal - oral | (potential for parenteral)
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What is virological diagnosis of hepatitis A?
HAV IgM antibodies indicate infection (present in the serum at onset of symptoms and usually decline to a non-detectable level over 3-6 months) HAV IgG antibodies indicates immunity
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What is managment of HAV?
Supportive
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What are means of prevention of HAV ifnection?
Good personal hygiene and sanitation Isolation not necessary Prophylaxis of close contacts of patients with HAV with human normal immunoglobulin
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Who might be offered hep A vaccination?
For those at risk of exposure such as: - Sewage workers - Seronegative hamophiliacs - MSM with multiple sexual partners - Travellers to endemic areas - PWID - Patients with hep C get the vaccination becuse the illness may be more serious
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How do liver enzymes react to hepatitis?
Incerase in ALT and AST
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What is the prognosis of Hep A?
Chronic liver damage does not occur Lifelong immunity follows infection Uncommon complications include: * Prolonged cholestatic jaundice * Relapsing hepatitis * Haematological problems such as aplastic anaemia
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What is the presentation of hepatitis B infection?
Anorexia Lethargy Nausea Fever Abdominal discomfort Arthralgia Urticarial skin lesions often precede the development of darkly coloured urine and jaundice
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HBV infection outcomes
basically the majority of people recover, for those who don't you might suffer from different activity states of the hepatitis - may be chronic or it can even result in fulminant hepatic necrosis. Result of persistent hepatitis is cirrhosis, liver cancer and needing a liver transplant.
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What are the hepatitis b markers for viral replication?
Serum HBeAg HBV DNA
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What is the major identifier for acute and chronic hepatitis B infection?
HBsAg
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What seroogical markers in hepatitis might make you think that someone is particularly infectious?
HBeAg positive chronically infected These people are at high risk of developing chronic liver disease and hepatoma
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What are the mechanisms of transfer of HBV?
Vertical Horizontal (sexual, parenteral including needlestick, inapparent parenteral) Childhood horizontal transmission probably happens as a result of inapparent exposure to blood or body fluids.
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What are factors predisposing to increased risk of infection in the UK?
Injecting drug use Multiple sexual partners - both MSM or heterosexual Immigration from areas of high endemnicity Patients with a learning disability who live in residential care Patients win haemodialysis units or with haemophilia Sexual partners of those with the above risk factors Babies born to mothers who are at risk Tattooing or body piercing with non-sterile equipment Medical equipment if not adequately decontaminated
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When is a needle stick more likely to pass on HBV?
If it is HBeAg positive
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What antibody is the key antibody during acute infective period of hepatitis B?
Anti-HBcore IgM There is seroconversion to anti-HBs severeal weeks after the disappearance of HBsAg
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What is meant by the window period of HBV?
The only serological marker present is anti-HBC
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What is the definition of chronic HBV infection?
Persistence of HBsAg in the serum for more than 6 months
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What are long-term sequale of chronic hep B infection?
Chronic liver disease Membranous glomerulonephritis Polyarteritis nodosa
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What are potential complications for chronic HBV liver infection?
Cirrhosis Hepatoma
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Who is offered antiviral therapy?
If you have asymptomatic chronic HBV infection with raised ALT and are HBeAg positive Those with progressive liver disease Without cirrhosis and have 2 of the following: HBV DNA greater than 2,000 IU/ml Raised ALT Significant liver inflammation or fibrosis
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What is the first antigen to appear in hepatitis B?
surface antigen (HBsAg) is the first marker to appear and causes the production of anti-HBs
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What does anti-HBc imply?
Implies previous or current infection IgM anti-HBc appears during acute or recent hepatitis B infection and is present for about 6 months. IgG anti-HBc persists
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What are potential treatments for hepatitis B?
Pegylated alpha interferon Entecavir and tenofovir Advanced cirrhosis may warrant liver transplant, graft rejection reduced by giving the patient antiretroviral agents as well as Hepatitis B specific immunoglobulin
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What are the most important means of preventing HBV infection?
Immunisation Infection control procedures Screening of blood donors and transplant donors
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What is the main component of the HBV vaccination?
HBsAg produced by recombinant DNA technology
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How is passive immunity for hepatitis provided?
Hepatitis B specific immunoglobulin
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What is recommended for people with positive HBsAg who are about to undergo systemic chemotherapy?
Start them on prophylactic antiviral therapy for at least 6-12 months after its cessation Antiviral therapy may also be needed for those with positive anti-HBc (even if there are low HBsAg). These people may still have HBA DNA in there liver which may reactivate the HBV activation - acute liver failure
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How does acute HCV present?
Usually subclinical or mild Symptoms in 20% Malaise Anorexia Fatigue Severe hepatitis and jaundice can occur
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Outcomes of acute hep C infection
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What are known routes of transmission of HCV?
Shared “works” associated with IDU, including needles, syringes, filters, spoons. Blood products prior to heat treatment in 1989. Blood transfusion prior to antibody screening in 1991. Tattooing, ear piercing, body piercing or acupuncture with non-sterile equipment. Sexual transmission (\<5%; except higher risk during passive traumatic anal intercourse from a HIV/HCV individual). Mother-to-child. Household contacts sharing razors or toothbrushes. Medical or dental treatment if inadequately decontaminated equipment used (e.g. some developing countries).
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How is diagnosis achieved of HCV?
Antibody testing (IgG only athough this has v poor sensitivity) Detection of HCV antigen HCV RNA HCV RNA is the investigation of choice to diagnose acute infection whilst patients will eventually develop anti-HCV antibodies it should be remembered that patients who spontaneously clear the virus will continue to have anti-HCV antibodies
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How is HCV treated?
Treatment response varies according to the viral genotype A interferon with ribavarin For genotype1 HCV infection give protease enzyme inhibitor with a interferon and ribavarin. The goal is sustained viral response (virus undetectable for 6 months after antiviral therapy) Ribavarin is teratogenic
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How are potential preventative mesures for HepC?
Blood, organ and tissue donor screening are very important measures for reducing transmission. No post-exposure prophylaxis or vaccine is available. Other preventative measures include not sharing injecting equipment, avoiding sharing razors and toothbrushes, and covering cuts and skin lesions with waterproof dressings.
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What is hepatitis D always seen in conjunction with?
Hepatitis B virus
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What is coinfection and superinfection?
Co-infection is simultaneous infection with HDV and HBV. Superinfection is when a person with chronic HBV infection becomes infected with HDV. In both, the illness is more severe than HBV infection alone.
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What is the transmission mode for hepatits D?
Parenteral
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What is the virological diagnosis of HDV?
Tests are available to detect IgG and IgM antibody to HDV, HDV-RNA and HDAg in serum. Co-infection and superinfection can be distinguished by the presence of high level of anti-HBc IgM in co-infection.
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What is treatment for hepatitis as a result of HBV infection?
Pegylated alpha interferon ## Footnote Liver transplantation may offer some hope in fulminant hepatitis. Prevention of HBV infection also prevents HDV infection. Severe chronic hepatitis commonly follows HDV superinfection.
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What is the presentation of Hep E?
Like Hep A but carries a significant mortality in pregnant women (up to 20%)
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What is the route of infection in Hep E?
Faecal oral route
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What type of virus is HepE?
Henevirus Small RNA virus
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What are the genotypes of hepatitis E assocaited with developing countries?
1 and 2
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What are the global genotypes of hep E?
3 and 4 ## Footnote is associated with the increasing reports of sporadic infections in developed countries, including the UK, that have not until recent years been known to be endemic regions.
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What are serological tests for HepE?
IgG and IgM HEV-RNA
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What is the treatment for HepE?
No licensed treatment Ribavarin monotherapy in the immunocompromised
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What are ways to reduce transmission?
Good hygiene Good sanitation Adequate cooking of food Active immunisation with a subunit vaccine is available in China and it is possible that immunisation may eventually become available to protect vulnerable groups like pregnant women. Passive immunisation with HNIG available in the UK does not protect tropical travellers against HEV infection.
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The Daddy
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