Infectious Disease And STI Flashcards
1
Q
is associated with cavitating lesions when it causes pneumonia
A
Staphylococcus aureus
2
Q
Legionella is associated with deranged liver function tests when it causes pneumonia.
A
Other features include hyponatraemia, headache and dry cough. It is often associated with exposure to the bacteria through a contaminated aerosolised water supply, such as air conditioning.
3
Q
*** has the shortest erythrocytic replication cycle, leading to high parasite counts in short periods of time
A
P. knowlesi
4
Q
**** was previously used in the UK but has been since been discontinued. It involved injection of PPD equivalent to 100,000 units per ml to the skin over the flexor surface of the left forearm. It was then read 3-10 days later.
A
Heaf test
5
Q
Man returns from trip abroad with maculopapular rash and flu-like illness - think HIV seroconversion
A
HIV-1/2 Ab/Ag Immunoassay (fourth generation) is correct. This fourth-generation assay should be used to screen individuals for HIV as it will detect HIV-1 and HIV-2 antibodies (Ab) and antigens (Ag) with high sensitivity within a short window period (approximately 10 days after infection).
6
Q
. The HIV Western blot is an enzyme immunoassay for the in-vitro detection of antibodies to HIV in human serum or plasma. It is intended as a more specific confirmation test on blood or plasma specimens found repeatedly reactive using a screening procedure. It is not recommended for screening.
A
7
Q
Bacterial vaginosis - overgrowth of predominately Gardnerella vaginalis
A
8
Q
Immunocompromised patients with toxoplasmosis are treated with pyrimethamine plus sulphadiazine
A
CD4 count of < 100 cells/mm³. The diagnosis is most strongly supported by the presence of multiple ring-enhancing lesions on CT imaging.
9
Q
Amphotericin B + flucytosine would be an appropriate treatment regimen for***. This patient is also at risk of developing cryptococcal infections, but imaging would not show ring-enhancing lesions.
A
cryptococcal meningitis
10
Q
False positive VDRL/RPR: ‘SomeTimes Mistakes Happen’ (SLE, TB, malaria, HIV)
A
11
Q
Coagulase positive
A
The coagulase test is used to differentiate between different Staphylococcus species and often returns from the lab before determination of the exact species. Staph aureus is the most important of the coagulase positive Staphylococcus species and is highly pathogenic.
Coagulase-negative Staph species are most likely to be skin commensal organisms of relatively low pathogenicity, such as Staph epidermidis or Staph saprophyticus, although some may still cause deeper infection or sepsis.
12
Q
If a patient has had 5 doses of tetanus vaccine, with the last dose < 10 years ago, they don’t require a booster vaccine nor immunoglobulins, regardless of how severe the wound is
A
13
Q
Chickenpox infection during the first 20 weeks of pregnancy can cause foetal varicella syndrome. In the second of third trimester chickenpox can cause severe maternal disease. In late pregnancy infection (near delivery) there is a risk of neonatal varicella.
A
For susceptible women (negative antibodies) exposed in the first 20 weeks of pregnancy, varicella zoster immunoglobulin (VZIG) is recommended.
For susceptible women (negative antibodies) exposed from 20 weeks of pregnancy, either VZIG or aciclovir from days 7 to 14 after exposure is recommended.
14
Q
The reversal of the sleep wake cycle is typical of** (African sleeping sickness) and can be accompanied by behavioural changes.
A
trypanosomiasis
15
Q
is found in Tanzania (although the risk is low) and the initial symptoms may be similar but the later stages involve jaundice, abdominal pain and bleeding
A
Yellow fever
16
Q
A
17
Q
Pruritic rash on the buttocks or soles ?
A
Strongyloides stercoralis
18
Q
Tetanus toxin (tetanospasmin) blocks the release of the inhibitory neurotransmitters GABA and glycine resulting in continuous motor neuron activity
A
19
Q
An increase in cyclic adenosine monophosphate (cAMP) release refers to the action of the exotoxin secreted by
A
Bordetella pertussis
20
Q
Inhibition of acetylcholine (ACh) release refers to the action of botulinum toxin, released by Clostridium botulinum
A
Flaccid paralysis
21
Q
Inhibition of dopamine (D2) receptors refers to****, which may present somewhat similarly to tetanus with muscular rigidity. However, other symptoms would include autonomic dysfunction and hyperthermia, and a history of antipsychotic use would be present.
A
neuroleptic malignant syndrome
22
Q
Doxycycline is used to treat** meningitis, a type of neurosyphilis.
A
syphilitic
23
Q
Although ciprofloxacin is not a beta-lactam antibiotic, its use is strongly linked to the acquisition of MRSA as with all quinolone antibiotics.
A
24
Q
Suppression of MRSA from a carrier once identified
A
nose: mupirocin 2% in white soft paraffin, tds for 5 days
skin: chlorhexidine gluconate, od for 5 days. Apply all over but particularly to the axilla, groin and perineum
26
27
Japanese encephalitis can present with Parkinsonism- this is a sign of basal ganglia involvement
Temporal lobe , inflammation in this lobe, most commonly found in herpes simplex encephalitis, would be more likely to cause confusion, memory loss and emotional lability
28
Campylobacter infection is often self-limiting but if severe then treatment with clarithromycin may be indicated
29
******** frequently causes mild cases of pneumonia, otherwise referred to 'Walking pneumonia'. Systemic symptoms are less common, and it usually presents with a non-productive cough.
Mycoplasma pneumoniae
30
Coxiella presents may present with culture-negative endocarditis
Management
doxycycline
31
Direct contact transmission occurs through direct body contact with the tissues or fluids of an infected individual. Examples include conditions such as rabies infections and Staphylococcus.
32
breastfeeding is not contraindicated in mothers with hepatitis C
33
IgM antibodies against Mycoplasma pneumoniae react against human red blood cells at cold temperatures causing them to agglutinate.
This can be seen in a peripheral blood smear and is the reason Mycoplasma pneumoniae causes haemolytic anaemia.
34
Moraxella catarrhalis is gram-negative coccus that is implicated in infective exacerbation of COPD.
35
The clinical syndrome produced by ******* is an afebrile, descending, flaccid paralysis.
botulinum toxin
Presenting features typically include difficulty speaking or slurred speech, blurred or double vision, and/or dysphagia. Other features include ptosis and facial muscle weakness. Without treatment, paralysis may progress to the upper limbs, trunk, lower limbs and respiratory muscles.
36
botulinum toxin, a neurotoxin which irreversibly blocks the release of
acetylcholine
37
Staphylococcal toxic shock syndrome is characterised by fever, hypotension and a rash → desquamation
38
**** , which is also the most common cause of infectious intestinal disease in the UK. It is spread by the faecal-oral route and is classically preceded by several days of prodromal features - fever, malaise and headache, as seen here. It is associated with crampy abdominal pains.
Campylobacter jejuni
The illness is typically self-limiting, but treatment with clarithromycin or ciprofloxacin may be advised for severe illness or immunocompromised patients.
39
. This is common amongst travellers. It instead presents with watery stools, abdominal cramps and nausea
Escherichia coli
40
is a parasitic infection and a cause of prolonged, non-bloody diarrhoea.
Giardiasis
41
. This is the causative organism of typhoid fever, rather than salmonellosis, which is caused by other subtypes of the Salmonella enterica species. While salmonellosis would present similarly to C. jejuni infection, typhoid fever would instead present with a rose-coloured rash, constipation, abdominal pain and high fever.
Salmonella typhi
42
. This is one of several species of the Shigella genus that cause infectious diarrhoea. Although it also presents with bloody diarrhoea, it often leads to concurrent vomiting
Shigella dysenteriae
43
Schistosoma haematobium causes haematuria
Schistosomiasis is the most common cause of bladder calcification worldwide
single oral dose of praziquantel
44
Mucocutaneous leishmaniasis
caused by Leishmania braziliensis
skin lesions may spread to involve mucosae of nose, pharynx etc
45
Latent TB Rx
The 2016 NICE guidelines on Tuberculosis (TB) advice that if a Mantoux test is positive (>5mm) then the patient should be screened for active TB. If there is no evidence of active TB and an interferon-gamma release assay is positive then you should consider treatment for latent TB. The two options are:
3 months of isoniazid with pyridoxine and rifampicin
6 months of isoniazid with pyridoxine
46
The 'valency' of a vaccine denotes the number of distinct antigenic components or serotypes a vaccine can protect against
47
***** work by inhibiting bacterial protein synthesis through binding to the 50S ribosomal subunit, preventing elongation of the peptide chain. This mechanism effectively halts bacterial growth
Macrolides
48
****** , which inhibit bacterial DNA gyrase or topoisomerase, interfering with DNA replication
fluoroquinolones
49
Disrupts bacterial membrane integrity , it refers to antibiotics like******, which damage the bacterial cell membrane, leading to leakage of cellular contents
polymyxins
50
Inhibits bacterial cell wall synthesis, it describes the mechanism of action of******, which inhibit the synthesis of peptidoglycan, a critical component of the bacterial cell wall
beta-lactam antibiotics (e.g., penicillins, cephalosporins)
51
Inhibits bacterial folate synthesis , it refers to antibiotics like********, which inhibit bacterial folate synthesis, essential for DNA and RNA production
sulfonamides and trimethoprim
52
The combination of fever, hepatosplenomegaly, and pancytopaenia in a patient returning from an endemic area like South Sudan is suggestive of visceral leishmaniasis
This diagnosis is supported by the patient’s travel to an endemic region (South Sudan), prolonged fever, hepatosplenomegaly, pancytopaenia, and
bone marrow aspirate showing amastigotes in macrophages
53
Chikungunya can present with debilitating joint pain
Chikungunya typically causes a non-haemorrhagic rash, often maculopapular in nature, with red or pink spots that start on the trunk and spread to the limbs
54
Supportive therapy is the mainstay of treatment in Cryptosporidium diarrhoea
55
Pelvic inflammatory disease: oral ofloxacin + oral metronidazole can be used second-line
56
Recurrent herpes outbreaks in pregnancy should be treated with suppressive therapy; risk of transmission to the baby is low and aciclovir is safe to use in pregnant women
57
lower urinary tract infection which should be treated with antibiotics.
The clue to finding the correct answer is the fact that despite being leucocyte positive, the urine dipstick is nitrite negative.
Gram negative organisms test positive on the nitrite test as they convert nitrates to nitrites for energy.
Gram positive organisms are unable to reduce nitrate to nitrite and therefore, test negative.
58
Feature of severe falciparum malaria
schizonts on a blood film
parasitaemia > 2%
hypoglycaemia
acidosis
temperature > 39 °C
severe anaemia
complications as below
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)
59
HPV vaccination should be offered to men who have sex with men under the age of 45 to protect against anal, throat and penile cancers
60
Genital ulcers
painful: herpes much more common than chancroid
painless: syphilis more common than lymphogranuloma venereum
Chancroid- painful ulcer and LN
LGV - painless pustule and painful LN
Syphillis - painless ulcer
Genital herpes - painful multiple ulcers HSV 2
61
Antivirals are of no benefit in the treatment of confirmed viral meningitis
It is the most common cause of viral meningitis in the adult population but can cause a range of different diseases, in both adults and children. Although the range of diseases caused by these viruses is broad, notable disease entities include Hand, Foot and Mouth disease, herpangina and pericarditis.
62
There is a measles outbreak in The Democratic Republic of the Congo that the World Health Organisation (WHO) has reported as the world's largest and fastest-moving epidemic.
63
Terbinafine inhibits the fungal enzyme squalene epoxidase, causing cellular death
64
Viral meningitis
whilst awaiting the results of the lumbar puncture, treatment should be supportive and if there is any question of bacterial meningitis or of encephalitis, the patient should be commenced on broad-spectrum antibiotics with CNS penetration e.g. ceftriaxone and aciclovir intravenously. This is particularly the case if the patient has risk factors e.g. elderly, immunocompromised
65
Yellow fever typically presents with flu like illness → brief remission→ followed by jaundice and haematemesis
Tocilizumab treatment for rheumatoid arthritis means the yellow fever vaccine is contraindicated and would put the patient at increased risk of developing the illness.
66
. This is a cause of viral hemorrhagic fever and can cause flu-like symptoms and subsequent jaundice and hemorrhagic complications. However, a period of remission before the recrudescence of the disease is not typical.
Ebola
67
. This is another viral hemorrhagic fever that can result in fever and bleeding from mucus membranes. However, it is mainly endemic in West Africa
Lassa fever
68
Intramuscular ceftriaxone is the treatment of choice for Gonorrhoea
If sensitivities are known (and the organism is sensitive to ciprofloxacin) then a single dose of oral ciprofloxacin 500mg should be given
if ceftriaxone is refused (e.g. needle-phobic) then oral cefixime 400mg (single dose) + oral azithromycin 2g (single dose) should be used
69
Mumps meningitis is associated with a low glucose in up to a third of patients
*mumps is unusual in being associated with a low glucose level in a proportion of cases. A low glucose may also be seen in herpes encephalitis
70
Severe falciparum malaria - intravenous artesunate
Intravenous artemether-lumefantrine is not an appropriate choice because there is no intravenous formulation of this combination drug available. Artemether-lumefantrine is only available in oral form and, as mentioned earlier, should be reserved for uncomplicated cases of falciparum malaria.
71
early latent syphilis is treated with benzathine penicillin G 2.4 million units IM as a single dose, and late latent syphilis is treated with benzathine penicillin G 2.4 million units IM weekly for three weeks (three doses total)
72
In a review of UK cases of anthrax associated with intravenous drug use, eschar was not always present. Although treatment would be based on sensitivities, cutaneous anthrax is typically treated with ciprofloxacin or doxycycline.
73
******** is a Gram-positive bacillus which has the unusual ability to multiply at low temperatures. It is typically spread via contaminated food, typically unpasteurised dairy products. Infection is particularly dangerous to the unborn child where it can lead to miscarriage.
Listeria monocytogenes
74
Kaposi's sarcoma is caused by HHV-8 infection in HIV positive individuals
painless purple plaques on the lower legs, which have been slowly enlarging over months. similar lesions on the trunk and a purple mass inside the mouth.
75
******competitively inhibiting the tubular secretion of creatinine. ****** can cause a reversible increase in serum creatinine by inhibiting the tubular secretion of creatinine without affecting glomerular filtration rate (GFR). This does not signify true renal impairment but rather an artificial rise in serum creatinine.
Trimethoprim
76
Intravenous dexamethasone should be given prior to or with the first dose of antibiotic to reduce the risk of neurological sequelae by reducing cerebrospinal inflammation. If pneumococcal meningitis is suspected or confirmed from clinical features, cerebrospinal fluid parameters or culture results, then dexamethasone should be continued for 4 days. It should be stopped if another causative organism is strongly suspected or confirmed.
77
Amoebiasis should be considered in the presentation of dysentery after a long incubation period
treatment
oral metronidazole
a 'luminal agent' (to eliminate intraluminal cysts) is recommended usually as well e.g. diloxanide furoate
stool microscopy may show trophozoites if examined within 15 minutes or kept warm (known as a 'hot stool')
78
P jiroveciii IOC
BAL
cannot culture from sputum
BAL is the gold standard investigation for diagnosing PJP, with a sensitivity of over 90% and specificity approaching 100%. The procedure allows for direct microscopic examination of respiratory specimens to identify the characteristic cysts and trophozoites of P. jirovecii.
79
A typical exam question would be of a patient who presents with vomiting after ingesting reheated rice
Bacillus cereus
80
hepatitis in a pregnant woman - think hepatitis E
81
Mycoplasma pneumonia - treat with doxycycline or a macrolide
82
M. tuberculosis can cause hypoadrenalism
83
Exchange transfusion should be considered in cases of severe parasitaemia (>10%)
Falciparum
Severe falciparum malaria
a parasite counts of more than 2% will usually need parenteral treatment irrespective of clinical state
intravenous artesunate is now recommended by WHO in preference to intravenous quinine
if parasite count > 10% then exchange transfusion should be considered
shock may indicate coexistent bacterial septicaemia - malaria rarely causes haemodynamic collapse
84
85
Stereotypes are alive and well in the MRCP exam. For questions involving businessmen always consider sexually transmitted infections. The HIV prevalence rate in Kenya is currently around 8%.
Infection with HIV can lead to an acute flu-like illness during seroconversion approximately 1-2 weeks post-infection. While India has a higher prevalence of HIV compared to the United Kingdom—and it is indeed an MRCP favourite scenario for describing a businessman returning from overseas with HIV—the current clinical picture does not align with seroconversion; the severity of illness here is too great and includes signs and symptoms such as haemoptysis, night sweats, and upper lobe consolidation that are atypical for seroconversion. Moreover, this presentation does not correspond with opportunistic infection by Pneumocystis jirovecii, which typically manifests with exertional dyspnoea and a diffuse ground-glass appearance on chest x-ray.
86
Tetracyclines inhibit the 30S subunit of ribosomes
Tetracyclines are commonly confused with macrolides, which inhibit the 50S subunit of ribosomes.
87
hyponatraemia, which is likely secondary to the syndrome of inappropriate antidiuretic hormone secretion (SIADH), a condition commonly associated with pulmonary TB.
88
Co-infection with Chlamydia trachomatis, which would not be covered by ceftriaxone, is common in individuals diagnosed with gonorrhoea. According to UK guidelines, dual therapy for both gonorrhoea and chlamydia should be offered due to high rates of co-infection.
89
Blackwater fever is a rare complication of malaria which can be fatal. It is caused by large intravascular haemolysis resulting in haemoglobinuria, anaemia, jaundice and acute kidney injury. Urine is classically black or dark red in colour.The cause of the massive haemolysis is unknown.
The treatment is with antimalarials, intravenous fluids and in some cases dialysis. Urinalysis reveals blood which is not seen on microscopy as it is haemoglobinuria.
90
ELISA is the first-line investigation for suspected Lyme disease in patients with no history of erythema migrans
91
Listeria in pregnancy
In pregnant women
pregnant women are almost 20 times more likely to develop listeriosis compared with the rest of the population due to changes in the immune system
fetal/neonatal infection can occur both transplacentally and vertically during childbirth
complications include miscarriage, premature labour, stillbirth and chorioamnionitis
diagnosis can only be made from blood cultures
treatment is with amoxicillin
92
If the patient has a history of immediate hypersensitivity reaction to penicillin or to cephalosporins the BNF recommends using chloramphenicol.
Meningitis
93
Necrotising fasciitis
it is characterised by acute onset and pain, swelling and erythema at the site of infection that rapidly worsens. The pain is often out of keeping with the physical appearance (initially), as is the case here. As it progresses, the skin will show signs of necrosis and crepitus/gas gangrene may develop - these are late signs. The correct answer for definitive management is surgical debridement, immediately (along with intravenous antibiotics).
94
Benznidazole is used in the acute phase of Chagas' disease to manage the illness
African trypanosomiasis, or sleeping sickness,
Management
early disease: IV pentamidine or suramin
later disease or central nervous system involvement: IV melarsoprol
American trypanosomiasis, or Chagas' disease
treatment is most effective in the acute phase using azole or nitroderivatives such as benznidazole or nifurtimox
chronic disease management involves treating the complications e.g., heart failure
95
Clostridium - Gram-positive rod
Other gram positive bacilli include:
Actinomyces sp.
Bacillus anthracis
Corynebacterium diphtheriae
Listeria monocytogenes
96
HIV RNA becomes detectable by NAAT in plasma approximately 10 days after infection
97
Conjugate vaccines are those that use a protein that attaches to the polysaccharide outer coat of the pathogen to make it more immunogenic.
This is because polysaccharides alone are not very immunogenic, especially in infants and young children. By linking these p olysaccharides to a protein, the immune system can recognise and respond more effectively to the pathogen.
pneumococcus (conjugate)
haemophilus (conjugate)
meningococcus (conjugate)
hepatitis B
human papillomavirus
98
******* binds with ergosterol, a component of fungal cell membranes, forming pores that cause lysis of the cell wall and subsequent fungal cell death
Amphotericin B
99
Why still using BCG
It is still used because it is protective against severe diseases in children, particularly TB meningitis and disseminated TB in children. It is thought to prevent 60 - 80% of cases of TB meningitis in children who received BCG as neonates.
100
Streptococcus pneumoniae is not associated with cavitating lung lesions.
Although lung cancer, Klebsiella pneumoniae, and pulmonary tuberculosis are all associated with cavitating lung lesions,
S aureus
S. aureus is associated with the development of cavitating lung lesions in the context of pneumonia, especially when caused by strains capable of producing a cytotoxin known as Panton-Valentine Leukocidin. This cytotoxin can often lead necrotic, hemorrhagic pneumonia and length stays in intensive care units for the patients affected.
101
Mycobacterium avium intracellulare is an atypical mycobacteria seen with the CD4 count is below 50.
Typical features include fever, sweats, abdominal pain and diarrhoea. There may be hepatomegaly and deranged LFTs. Diagnosis is made by blood cultures and bone marrow examination. Management is with rifabutin, ethambutol and clarithromycin
102
IV ceftriaxone should be used as first-line treatment of Lyme disease with disseminated or central nervous system involvement
103
Integrase inhibitors
block the action of integrase, a viral enzyme that inserts the viral genome into the DNA of the host cell
examples: raltegravir, elvitegravir, dolutegravir
104
Protease inhibitors (PI)
examples: indinavir, nelfinavir, ritonavir, saquinavir
105
Nucleoside analogue reverse transcriptase inhibitors (NRTI)
examples: zidovudine (AZT), abacavir, emtricitabine, didanosine, lamivudine, stavudine, zalcitabine, tenofovir
106
Entry inhibitors
maraviroc (binds to CCR5, preventing an interaction with gp41), enfuvirtide (binds to gp41, also known as a 'fusion inhibitor')
107
P. knowlesi has the shortest erythrocytic replication cycle, leading to high parasite counts in short periods of time
rapid malaria antigen test does not rule out Plasmodium knowlesi as this test primarily targets antigens specific to Plasmodium falciparum and may not detect other species.
Plasmodium knowlesi has a 24-hour replication cycle which can lead to high levels of parasitaemia and severe disease, aligning with the patient's symptoms.
The patient's travel history to Thailand, a region in Southeast Asia, and the presence of early ring form trophozoites and late trophozoites on blood films are indicative of Plasmodium knowlesi infection. This species of malaria is known to be prevalent in this region.
108
as the African eye worm, is a filarial nematode endemic in the rain forests of West and Central Africa.
Loa loa
109
exercise-induced desaturation
PCP
110
bronchoalveolar lavage (BAL) often needed to demonstrate PCP (silver stain shows characteristic cysts)
Management
co-trimoxazole
IV pentamidine in severe cases
aerosolized pentamidine is an alternative treatment for Pneumocystis jiroveci pneumonia but is less effective with a risk of pneumothorax
steroids if hypoxic (if pO2 < 9.3kPa then steroids reduce risk of respiratory failure by 50% and death by a third)
111
Animal bite microbe?
These are generally polymicrobial but the most common isolated organism is Pasteurella multocida.
112
Tuberculoid leprosy is the preferred answer as this patient has limited skin lesions with the accompanying hypoesthesia. Accompanying thickened and tender nerves also contribute towards this diagnosis.
Management
WHO-recommended triple therapy: rifampicin, dapsone and clofazimine
113
All chlamydia contacts are offered treatment. Prompt treatment in this patient is essential as she is due to give birth soon and if the chlamydia is untreated she risks passing it on to her baby.
114
URTI symptoms + amoxicillin/amoxicillin → rash ?
glandular fever/EBV, also known as human herpesvirus 4, HHV-4
LN +
may be present in the anterior and posterior triangles of the neck, in contrast to tonsillitis which typically only results in the upper anterior cervical chain being enlarged
115
116
Hep B Mx
whilst NICE still advocate the use of pegylated interferon firstl-line other antiviral medications are increasingly used with an aim to suppress viral replication (not in a dissimilar way to treating HIV patients)
examples
include tenofovir, entecavir and telbivudine (a synthetic thymidine nucleoside analogue)
117
testing for anti-HBs is only recommended for those at risk of occupational exposure (i.e. Healthcare workers) and patients with chronic kidney disease. In these patients anti-HBs levels should be checked 1-4 months after primary immunisation
around 10-15% of adults fail to respond or respond poorly to 3 doses of the vaccine. Risk factors include age over 40 years, obesity, smoking, alcohol excess and immunosuppression
118
Bacteriocidal vs static
Antibiotics: bactericidal vs. bacteriostatic
Bactericidal antibiotics
penicillins
cephalosporins
aminoglycosides
nitrofurantoin
metronidazole
quinolones
rifampicin
isoniazid
Bacteriostatic antibiotics
chloramphenicol
macrolides
tetracyclines
sulphonamides
trimethoprim
119
GBS LP findings
albuminocytologic dissociation i.e., elevated protein levels without a corresponding increase in cell count
120
Campylobacter Rx
the BNF advises treatment if severe or the patient is immunocompromised.
Antibiotics are recommended if severe symptoms (high fever, bloody diarrhoea, or more than eight stools per day) or symptoms have lasted more than one week
121
Toxoplasmosis immunocompromised Rx
Effective combination therapy involves pyrimethamine, sulfadiazine and folinic acid for 4 to 6 weeks. The latter drug is given to prevent bone marrow suppression.
122
Integrase inhibitors ('gravirs') - blocks the enzyme that inserts the viral genome into the DNA of the host cell
123
Renal transplant + infection ?CMV
124
125
HIV: anti-retrovirals - P450 interaction
nevirapine (a NNRTI): induces P450
protease inhibitors: inhibits P450
126
secondary to pelvic inflammatory disease (PID) is the most common complication of gonorrhoea. It is the second most common cause of PID after Chlamydia.
Infertility
Local complications that may develop include urethral strictures, epididymitis and salpingitis (hence may lead to infertility). Disseminated infection may occur - see below
The new first-line treatment is a single dose of IM ceftriaxone 1g (i.e. no longer add azithromycin). If sensitivities are known (and the organism is sensitive to ciprofloxacin) then a single dose of oral ciprofloxacin 500mg should be given
if ceftriaxone is refused (e.g. needle-phobic) then oral cefixime 400mg (single dose) + oral azithromycin 2g (single dose) should be used
127
128
Key features of disseminated gonococcal infection
tenosynovitis
migratory polyarthritis
dermatitis (lesions can be maculopapular or vesicular)
129
Rifampicin inhibits RNA synthesis
130
Lassa fever is contracted by contact with the excreta of infected African rats (Mastomys rodent) or by person-to-person spread
131
is a condition caused by the nematode Loa loa and the condition is initially asymptomatic. If symptoms occur, it can present with areas of angioedema
Loiasis
132
Kala-azar, also known as visceral leishmaniasis is the result of a parasitic infection spread by sand flies.
It presents with fever and hepatosplenomegaly. It is more commonly seen in travellers from Brazil, Ethiopia, India, Kenya, Somalia, South Sudan and Sudan.
133
Yellow fever typically presents with flu like illness → brief remission→ followed by jaundice and haematemesis
Yellow fever
Type of viral haemorrhagic fever (also dengue fever, Lassa fever, Ebola).
Basics
zoonotic infection: spread by Aedes mosquitos
incubation period = 2 - 14 days
Features
may cause mild flu-like illness lasting less than one week
classic description involves sudden onset of high fever, rigors, nausea & vomiting. Bradycardia may develop. A brief remission is followed by jaundice, haematemesis, oliguria
if severe jaundice, haematemesis may occur
Councilman bodies (inclusion bodies) may be seen in the hepatocytes
134
******, also known as Pentostam, is incorrect. It is an antimonial compound used in the treatment of leishmaniasis, a parasitic disease caused by Leishmania spp., which are transmitted by sandfly bites.
Sodium stibogluconate
135
because it's an antimicrobial drug mainly indicated for Chagas disease (American trypanosomiasis) caused by Trypanosoma cruzi,
Benznidazole
136
Diphtheria mx
Investigations
culture of throat swab: uses tellurite agar or Loeffler's media
Management
intramuscular penicillin
diphtheria antitoxin
137
HIV, neuro symptoms, headache, CSF India ink positive - CNS cryptococcal infection
CSF India ink stain is the most appropriate initial confirmation test for this diagnosis. It works by staining the background of the CSF specimen, highlighting the clear, uncoloured capsule surrounding the Cryptococcus yeast cells, which appear as large, round, pale structures. This test is quick, specific, and widely used in diagnosing CNS cryptococcal infections, especially in HIV patients
138
Whilst tackling MRSA requires a multi-pronged approach the evidence base demonstrates that ******** is the single most important step
hand hygiene
139
Tetracyclines can cause photosensitivity
140
Diabetes is the strongest risk factor for the development of melioidosis
141
Cholera Rx
Doxycycline
Ciprofloxacin
142
A relative bradycardia is often seen in typhoid fever'. Relative bradycardia, also known as******, is a clinical feature of typhoid fever caused by Salmonella typhi.
Faget's sign
143
A tetanus booster is not recommended in the UK if the patient is already immunized.
high risk wound and symptoms so tetanus immunuglobulin would be advised alongside a muscle relaxant such as diazepam, and ventilatory support if needed.
intramuscular human tetanus immunoglobulin for high-risk wounds (e.g. compound fractures, delayed surgical intervention, significant degree of devitalised tissue)
metronidazole is now preferred to benzylpenicillin as the antibiotic of choice
144
145
Fluctuating temperatures, transient arthralgia and myalgia, hyperhidrosis with a 'wet hay' smell. The clue in the history is his exposure to unpasteurised cheese.
Brucellosis
146
Ototoxicity, nephrotoxicity and red man syndrome. Red man syndrome is associated with flushing or a maculopapular rash. The proposed mechanism is non IgE mediated mast cell degranulation. Red man syndrome is more common with higher flow rates of infusion. Treatment includes antihistamines.
Vancomycin
147
is an infectious thrombophlebitis of the internal jugular vein.
Lemierre's syndrome
It most often occurs secondary to a bacterial sore throat caused by Fusobacterium necrophorum leading to a peritonsillar abscess. A combination of spread of the infection laterally from the abscess and compression lead to thrombosis of the IJV.
Patients will present with a history of bacterial sore throat followed by neck pain, stiffness and tenderness (may be mistaken for meningitis) and systemic involvement (fevers, rigors, etc). Septic pulmonary emboli may also occur.
148
Groove sign is separation inguinal nodes by the inguinal ligament and is characteristic of the disease.
Lymphogranuloma venerum (LGV)
149
There is no known clearance of Treponema pallidum without antibiotic treatment
150
Leprosy Rx
multibacillary leprosy (>6 lesions) so should have triple therapy with rifampicin, dapsone and clofazimine for 12 months. For paucibacillary leprosy (5 or less lesions) you should give rifampicin and dapsone for 6 months.
151
Non gonococcal urethritis, Rx
Oral Azithromycin or doxycycline
Mc - chlamydia,
Mycoplasma genitalium ,thought to cause more symptoms than Chlamydia
less common causes
Ureaplasma urealyticum
Trichomonas vaginalis
Escherichia coli
152
PCP Rx
Management
co-trimoxazole
IV pentamidine in severe cases
aerosolized pentamidine is an alternative treatment for Pneumocystis jiroveci pneumonia but is less effective with a risk of pneumothorax
steroids if hypoxic (if pO2 < 9.3kPa then steroids reduce risk of respiratory failure by 50% and death by a third)
CXR: typically shows bilateral interstitial pulmonary infiltrates but can present with other x-ray findings e.g. lobar consolidation. May be normal
exercise-induced desaturation
sputum often fails to show PCP, bronchoalveolar lavage (BAL) often needed to demonstrate PCP (silver stain shows characteristic cysts)
153
Bloody dysentery DD?
Campylobacter usually has an incubation period of 48-72 hours.
Salmonella has an incubation period of 12-48 hours.
Amoebiasis - chronic months
Shigella has an incubation period of 48-72 hours.
154
Fever and the presence of a eschar in a patient returning from South East Asia is strongly suggestive of scrub typhus (caused by Orientia tsutsugamushi) and Rx ?
necessitates urgent treatment with doxycycline
155
Ulceration limits barrier protection to HIV infection. A low CD4 count is not associated with increased transmission rate, but an increased HIV viral load. Genito-urinary infection can increase transmission rates but genital warts has not been shown to do so. Diabetes would increase the rates of bacterial and fungal infections but not viral ones. Circumcision is protective to HIV transmission.
156
The most common causes of viral meningitis in adults are
enteroviruses - Coxackie virus
157
Adult onset stills disease
Leukocytes and pharyngitis and joint involvement
fever and pharyngitis but typically has joint involvement, a salmon-coloured rash and leucocytosis with granulocyte predominance rather than eosinophilia
158
Acute toxoplasmosis in the immunocompetent patient can mimic acute EBV infection (low-grade fever, generalised lymphadenopathy with prominent cervical lymph nodes and malaise) and should be suspected with negative EBV serology. Pregnancy testing and counselling is paramount due to the risk of congenital toxoplasmosis
159
Mucocutaneous ulceration following insect bite.
Leishmania braziliences.
160
Cryptosporidium
Cryptosporidium is the most common infective cause of diarrhoea in HIV patients. It is an intracellular protozoa and has an incubation period of 7 days. Presentation is very variable, ranging from mild to severe diarrhoea.
A modified Ziehl-Neelsen stain (acid-fast stain) of the stool may reveal the characteristic red cysts of Cryptosporidium
Management is with conservative
161
Patients with peritonsillar abscesses can develop Lemierre's syndrome (thrombophlebitis of the IJV)- this can present with neck pain, and can result in septic pulmonary embolism
162
Block HIV reverse transcriptase thereby preventing the HIV virion from replicating
NNRTI
163
Inhibit reverse transcription by being incorporated into the growing viral DNA strand and preventing further addition of nucleotides
NRTI
164
Binding to the catalytic site of the HIV protease, thereby preventing the cleavage of viral polyprotein precursors into mature, functional proteins
Protease inhibitors
165
Meningitis
If the patient has a history of immediate hypersensitivity reaction to penicillin or to cephalosporins the BNF recommends using chloramphenicol.
166
Tetanus toxin inhibits the release of inhibitory neurotransmitters (glycine and GABA at synapses).
Tetrodotoxin, produced by several fish species including pufferfish, is a sodium channel blocker. Curare, the poison used to tip arrows by the native people of Central and South America, is a nicotinic acetylcholine receptor blocker. Chlorotoxin, from the deathstalker scorpion, is a chloride channel blocker.
167
The patient has wound botulism, as characterised by descending flaccid paralysis and cranial nerve signs.
Intravenous drug users are at higher risk of botulism, particularly if they engage in skin popping or muscle popping.
168
Congo red stain
Amyloidosis
169
Rose Bengal can be applied to corneal scrapings to diagnose
fungal keratitis or Acanthamoeba infections
170
Pearl's stain has applications in diagnosing conditions such as hemochromatosis
This stain involves the reaction between potassium ferrocyanide and ferric ions, resulting in a bright blue color where iron accumulates.
171
Rubeanic acid
It forms a green complex with copper ions and can be useful in diagnosing Wilson's disease or assessing copper levels in liver biopsies.
172
Human bite
Common organisms include:
Streptococci spp.
Staphylococcus aureus
Eikenella
Fusobacterium
Prevotella
