Infectious diseases Flashcards

Question

Describe the standard treatment of TB

Answer 1

The standard therapy for treating active tuberculosis is: Initial phase - first 2 months (RIPE) Rifampicin Isoniazid Pyrazinamide Ethambutol (the 2006 NICE guidelines now recommend giving a 'fourth drug' such as ethambutol routinely - previously this was only added if drug-resistant tuberculosis was suspected) Continuation phase - next 4 months Rifampicin Isoniazid

Answer 2

The treatment for latent tuberculosis is 3 months of isoniazid (with pyridoxine) and rifampicin OR 6 months of isoniazid (with pyridoxine)

Answer 3

Patients with meningeal tuberculosis are treated for a prolonged period (at least 12 months) with the addition of steroids

Answer 4

Directly observed therapy with a three times a week dosing regimen may be indicated in certain groups, including: homeless people with active tuberculosis patients who are likely to have poor concordance all prisoners with active or latent tuberculosis

Answer 5

Immune reconstitution disease occurs typically 3-6 weeks after starting treatment often presents with enlarging lymph nodes

Answer 6

Rifampicin

Answer 7

Pyrazinamide

Answer 8

optic neuritis: check visual acuity before and during treatment

Answer 9

all infants (aged 0 to 12 months) living in areas of the UK where the annual incidence of TB is 40/100,000 or greater all infants (aged 0 to 12 months) with a parent or grandparent who was born in a country where the annual incidence of TB is 40/100,000 or greater. The same applies to older children but if they are 6 years old or older they require a tuberculin skin test first previously unvaccinated tuberculin-negative contacts of cases of respiratory TB previously unvaccinated, tuberculin-negative new entrants under 16 years of age who were born in or who have lived for a prolonged period (at least three months) in a country with an annual TB incidence of 40/100,000 or greater healthcare workers prison staff staff of care home for the elderly those who work with homeless people

Answer 10

The vaccine contains live attenuated Mycobacterium bovis. It also offers limited protection against leprosy.

Answer 11

any person being considered for the BCG vaccine must first be given a tuberculin skin test. The only exceptions are children < 6 years old who have had no contact with tuberculosis given intradermally, normally to the lateral aspect of the left upper arm BCG can be given at the same time as other live vaccines, but if not administered simultaneously there should be a 4 week interval

Answer 12

Contraindications previous BCG vaccination a past history of tuberculosis HIV pregnancy positive tuberculin test (Heaf or Mantoux) The BCG vaccine is not given to anyone over the age of 35, as there is no evidence that it works for people of this age group.

Answer 13

Mycoplasma pneumoniae is a cause of atypical pneumonia which often affects younger patients. It is associated with a number of characteristic complications such as erythema multiforme and cold autoimmune haemolytic anaemia. Epidemics of Mycoplasma pneumoniae classically occur every 4 years. It is important to recognise atypical pneumonia as it may not respond to penicillins or cephalosporins due to it lacking a peptidoglycan cell wall.

Answer 14

Features the disease typically has a prolonged and gradual onset flu-like symptoms classically precede a dry cough bilateral consolidation on x-ray

Answer 15

cold agglutins (IgM): may cause an haemolytic anaemia, thrombocytopenia erythema multiforme, erythema nodosum meningoencephalitis, Guillain-Barre syndrome and other immune-mediated neurological diseases bullous myringitis: painful vesicles on the tympanic membrane pericarditis/myocarditis gastrointestinal: hepatitis, pancreatitis renal: acute glomerulonephritis

Answer 16

Investigations diagnosis is generally by Mycoplasma serology positive cold agglutination test → peripheral blood smear may show red blood cell agglutination

Answer 17

Management doxycycline or a macrolide (e.g. erythromycin/clarithromycin)

Answer 18

Legionnaire's disease is caused by the intracellular bacterium Legionella pneumophilia. It typically colonizes water tanks and hence questions may hint at air-conditioning systems or foreign holidays. Person-to-person transmission is not seen

Answer 19

Features flu-like symptoms including fever (present in > 95% of patients) dry cough relative bradycardia confusion lymphopaenia hyponatraemia deranged liver function tests pleural effusion: seen in around 30% of patients

Answer 20

Investigations diagnositic test of choice:urinary antigen chest x-ray findings are non-specific but may include: a mid-to-lower zone predominance of patchy consolidation pleural effusions in around 30%

Answer 21

Management treat with erythromycin/clarithromycin

Answer 22

Phenoxymethylpenicillin (erythromycin alone if penicillin-allergic)

Answer 23

Infectious mononucleosis (glandular fever) is caused by the Epstein-Barr virus (EBV, also known as human herpesvirus 4, HHV-4) in 90% of cases. Less frequent causes include cytomegalovirus and HHV-6. It is most common in adolescents and young adults.

Answer 24

The classic triad of sore throat, pyrexia and lymphadenopathy is seen in around 98% of patients: sore throat lymphadenopathy: 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 pyrexia

Answer 25

Other features include: malaise, anorexia, headache palatal petechiae splenomegaly - occurs in around 50% of patients and may rarely predispose to splenic rupture hepatitis, transient rise in ALT lymphocytosis: presence of 50% lymphocytes with at least 10% atypical lymphocytes haemolytic anaemia secondary to cold agglutins (IgM)

Answer 26

a maculopapular, pruritic rash develops in around 99% of patients who take ampicillin/amoxicillin whilst they have infectious mononucleosis

Answer 27

Symptoms typically resolve after 2-4 weeks.

Answer 28

Diagnosis heterophil antibody test (Monospot test) NICE guidelines suggest FBC and Monospot in the 2nd week of the illness to confirm a diagnosis of glandular fever.

Answer 29

Management is supportive and includes: rest during the early stages, drink plenty of fluid, avoid alcohol simple analgesia for any aches or pains consensus guidance in the UK is to avoid playing contact sports for 4 weeks after having glandular fever to reduce the risk of splenic rupture

Answer 30

Mumps is a caused by RNA paramyxovirus and tends to occur in winter and spring

Answer 31

Spread by droplets respiratory tract epithelial cells → parotid glands → other tissues infective 7 days before and 9 days after parotid swelling starts incubation period = 14-21 days

Answer 32

Clinical features fever malaise, muscular pain parotitis ('earache', 'pain on eating'): unilateral initially then becomes bilateral in 70%

Answer 33

Prevention MMR vaccine: the efficacy is around 80%

Answer 34

Management rest paracetamol for high fever/discomfort notifiable disease

Answer 35

Complications orchitis - uncommon in pre-pubertal males but occurs in around 25-35% of post-pubertal males. Typically occurs four or five days after the start of parotitis hearing loss - usually unilateral and transient meningoencephalitis pancreatitis

Answer 36

bronchiolitis

Answer 37

common cold

Answer 38

COPD exac, Community-acquired pneumonia Most common cause of bronchiectasis exacerbations Acute epiglottitis

Answer 39

Pneumonia, particularly following influenza

Answer 40

Phenoxymethylpenicillin

Answer 41

Amoxicillin (erythromycin if penicillin-allergic)

Answer 42

Flucloxacillin (erythromycin if penicillin-allergic)

Answer 43

Amoxicillin

Answer 44

metronidazole

Answer 45

Topical hydrogen peroxide, oral flucloxacillin or erythromycin if widespread

Answer 46

Cellulitis is most commonly caused by infection with Streptococcus pyogenes or less commonly Staphylcoccus aureus. The majority of cases resolve with oral antibiotics.

Answer 47

The diagnosis of cellulitis is clinical. No further investigations are required in primary care. Bloods and blood cultures may be requested if the patient is admitted and septicaemia is suspected.

Answer 48

Eron classification Class Features I There are no signs of systemic toxicity and the person has no uncontrolled co-morbidities II The person is either systemically unwell or systemically well but with a co-morbidity (for example peripheral arterial disease, chronic venous insufficiency, or morbid obesity) which may complicate or delay resolution of infection III The person has significant systemic upset such as acute confusion, tachycardia, tachypnoea, hypotension, or unstable co-morbidities that may interfere with a response to treatment, or a limb-threatening infection due to vascular compromize IV The person has sepsis syndrome or a severe life-threatening infection such as necrotizing fasciitis

Answer 49

They recommend the following that we admit for intravenous antibiotics the following patients: CKS Has Eron Class III or Class IV cellulitis. Has severe or rapidly deteriorating cellulitis (for example extensive areas of skin). Is very young (under 1 year of age) or frail. Is immunocompromized. Has significant lymphoedema. Has facial cellulitis (unless very mild) or periorbital cellulitis.

Answer 50

Eron Class I oral antibiotics NICE oral flucloxacillin as first-line treatment for mild/moderate cellulitis oral clarithromycin, erythromycin (in pregnancy) or doxycycline is recommended in patients allergic to penicillin

Answer 51

Eron Class III-IV admit NICE recommend: oral/IV co-amoxiclav, oral/IV clindamycin, IV cefuroxime or IV ceftriaxone

Answer 52

The majority of bites seen in everyday practice involve dogs and cats. These are generally polymicrobial but the most common isolated organism is Pasteurella multocida. Management cleanse wound. Puncture wounds should not be sutured closed unless cosmesis is at risk current BNF recommendation is co-amoxiclav if penicillin-allergic then doxycycline + metronidazole is recommended

Answer 53

Human bites commonly cause multimicrobial infection, including both aerobic and anaerobic bacteria. Common organisms include: Streptococci spp. Staphylococcus aureus Eikenella Fusobacterium Prevotella Co-amoxiclav is recommended, as for animal bites. The risk of viral infections such as HIV and hepatitis C should also be considered.

Answer 54

Cat scratch disease is generally caused by the Gram negative rod Bartonella henselae Features fever history of a cat scratch regional lymphadenopathy headache, malaise

Answer 55

Co-amoxiclav (clarithromycin, + metronidazole if penicillin-allergic)

Answer 56

Flucloxacillin* (clarithromycin, erythromycin or doxycycline if penicillin-allergic)

Answer 57

The following criteria should be met to determine who would benefit from active post-exposure prophylaxis: 1. significant exposure to chickenpox or herpes zoster e.g. exposure to limited, covered-up shingles may not warrant post-exposure prophylaxis 2. a clinical condition that increases the risk of severe varicella; this includes immunosuppressed patients, neonates and pregnant women e.g. long-term steroids, methotrexate and other common immunosuppressants 3. no antibodies to the varicella virus ideally all at-risk exposed patients should have a blood test for varicella antibodies this should not, however, delay post-exposure prophylaxis past 7 days after initial contact Patients who fulfill the above criteria should be given varicella-zoster immunoglobulin (VZIG).

Answer 58

Bed bugs describes a variety of clinical problems including itchy skin rashes, bites and allergic symptoms secondary to infestation with Cimex hemipteru. Bedbug infestation seems to be an increasingly common presentation within UK general practice. Bedbugs thrive in mattresses or fabrics, and can be extremely difficult to eradicate. Topical hydrocortisone is suitable to control itch, but definitive management is through a pest management company and fumigation of the house. Bed bug numbers may be controlled by hot-washing bed linen and using mattress covers.

Answer 59

Lyme disease is caused by the spirochaete Borrelia burgdorferi and is spread by ticks.

Answer 60

Early features (within 30 days) erythema migrans 'bulls-eye' rash is typically at the site of the tick bite typically develops 1-4 weeks after the initial bite but may present sooner usually painless, more than 5 cm in diameter and slowlly increases in size present in around 80% of patients. systemic features headache lethargy fever arthralgia

Answer 61

Later features (after 30 days) cardiovascular heart block peri/myocarditis neurological facial nerve palsy radicular pain meningitis

Answer 62

Investigation NICE recommend that Lyme disease can be diagnosed clinically if erythema migrans is present erythema migrans is therefore an indication to start antibiotics enzyme-linked immunosorbent assay (ELISA) antibodies to Borrelia burgdorferi are the first-line test if negative and Lyme disease is still suspected in people tested within 4 weeks from symptom onset, repeat the ELISA 4-6 weeks after the first ELISA test. If still suspected in people who have had symptoms for 12 weeks or more then an immunoblot test should be done if positive or equivocal then an immunoblot test for Lyme disease should be done

Answer 63

Management of asymptomatic tick bites tick bites can be a relatively common presentation to GP practices, and can cause significant anxiety if the tick is still present, the best way to remove it is using fine-tipped tweezers, grasping the tick as close to the skin as possible and pulling upwards firmly. The area should be washed following. NICE guidance does not recommend routine antibiotic treatment to patients who've suffered a tick bite

Answer 64

Management of suspected/confirmed Lyme disease doxycycline if early disease. Amoxicillin is an alternative if doxycycline is contraindicated (e.g. pregnancy) people with erythema migrans should be commenced on antibiotic without the need for further tests 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)

Answer 65

Trimethoprim or nitrofurantoin. Alternative: amoxicillin or cephalosporin

Answer 66

send a urine culture if: aged > 65 years visible or non-visible haematuria

Answer 67

if the pregnant woman is symptomatic: a urine culture should be sent in all cases should be treated with an antibiotic for first-line: nitrofurantoin (should be avoided near term) second-line: amoxicillin or cefalexin trimethoprim is teratogenic in the first trimester and should be avoided during pregnancy

Answer 68

asymptomatic bacteriuria in pregnant women: a urine culture should be performed routinely at the first antenatal visit Clinical Knowledge Summaries recommend an immediate antibiotic prescription of either nitrofurantoin (should be avoided near term), amoxicillin or cefalexin. This should be a 7-day course the rationale of treating asymptomatic bacteriuria is the significant risk of progression to acute pyelonephritis a further urine culture should be sent following completion of treatment as a test of cure

Answer 69

Men an immediate antibiotic prescription should be offered for 7 days as with non-pregnant women, trimethoprim or nitrofurantoin should be offered first-line unless prostatitis is suspected a urine culture should be sent in all cases before antibiotics are started NICE Clinical Knowledge Summaries state: 'Referral to urology is not routinely required for men who have had one uncomplicated lower urinary tract infection (UTI).'

Answer 70

Broad-spectrum cephalosporin or quinolone

Answer 71

Quinolone or trimethoprim

Answer 72

IM ceftriaxone

Answer 73

Gonorrhoea is caused by the Gram-negative diplococcus Neisseria gonorrhoeae. Acute infection can occur on any mucous membrane surface, typically genitourinary but also rectum and pharynx. The incubation period of gonorrhoea is 2-5 days

Answer 74

Features males: urethral discharge, dysuria females: cervicitis e.g. leading to vaginal discharge rectal and pharyngeal infection is usually asymptomatic

Answer 75

Management ciprofloxacin used to be the treatment of choice. However, there is increased resistance to ciprofloxacin (around 36% in the UK) and therefore cephalosporins are now more widely used there was a change in the 2019 British Society for Sexual Health and HIV (BASHH) guidelines. Previously the first-line treatment was IM ceftriaxone + oral azithromycin. 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

Answer 76

Disseminated gonococcal infection (DGI) and gonococcal arthritis may also occur, with gonococcal infection being the most common cause of septic arthritis in young adults. The pathophysiology of DGI is not fully understood but is thought to be due to haematogenous spread from mucosal infection (e.g. Asymptomatic genital infection). Initially there may be a classic triad of symptoms: tenosynovitis, migratory polyarthritis and dermatitis. Later complications include septic arthritis, endocarditis and perihepatitis (Fitz-Hugh-Curtis syndrome)

Answer 77

Key features of disseminated gonococcal infection tenosynovitis migratory polyarthritis dermatitis (lesions can be maculopapular or vesicular)

Answer 78

Doxycycline or azithromycin

Answer 79

Chlamydia is the most prevalent sexually transmitted infection in the UK and is caused by Chlamydia trachomatis, an obligate intracellular pathogen. Approximately 1 in 10 young women in the UK have Chlamydia. The incubation period is around 7-21 days, although it should be remembered a large percentage of cases are asymptomatic

Answer 80

Lymphogranuloma venereum (LGV) is caused by Chlamydia trachomatis. Typically infection comprises of three stages stage 1: small painless pustule which later forms an ulcer stage 2: painful inguinal lymphadenopathy stage 3: proctocolitis LGV is treated using doxycycline.

Answer 81

Features asymptomatic in around 70% of women and 50% of men women: cervicitis (discharge, bleeding), dysuria men: urethral discharge, dysuria

Answer 82

Potential complications epididymitis pelvic inflammatory disease endometritis increased incidence of ectopic pregnancies infertility reactive arthritis perihepatitis (Fitz-Hugh-Curtis syndrome)

Answer 83

Investigation traditional cell culture is no longer widely used nuclear acid amplification tests (NAATs) are now the investigation of choice urine (first void urine sample), vulvovaginal swab or cervical swab may be tested using the NAAT technique for women: the vulvovaginal swab is first-line for men: the urine test is first-line Chlamydiatesting should be carried out two weeks after a possible exposure

Answer 84

Screening in England the National Chlamydia Screening Programme is open to all men and women aged 15-24 years the 2009 SIGN guidelines support this approach, suggesting screening all sexually active patients aged 15-24 years relies heavily on opportunistic testing

Answer 85

doxycycline (7 day course) if first-line this is now preferred to azithromycin due to concerns about Mycoplasma genitalium. This infection is often coexistant in patients with Chlamydia and there is evidence of rising levels of macrolide resistance, hence why doxycycline is preferred if doxycycline is contraindicated / not tolerated then either azithromycin (1g od for one day, then 500mg od for two days) should be used

Answer 86

if pregnant then azithromycin, erythromycin or amoxicillin may be used. The SIGN guidelines suggest azithromycin 1g stat is the drug of choice 'following discussion of the balance of benefits and risks with the patient'

Answer 87

patients diagnosed with Chlamydia should be offered a choice of provider for initial partner notification - either trained practice nurses with support from GUM, or referral to GUM for men with urethral symptoms: all contacts since, and in the four weeks prior to, the onset of symptoms for women and asymptomatic men all partners from the last six months or the most recent sexual partner should be contacted contacts of confirmed Chlamydia cases should be offered treatment prior to the results of their investigations being known (treat then test)

Answer 88

Oral ofloxacin + oral metronidazole or intramuscular ceftriaxone + oral doxycycline + oral metronidazole

Answer 89

Benzathine benzylpenicillin or doxycycline or erythromycin

Answer 90

Syphilis is a sexually transmitted infection caused by the spirochaete Treponema pallidum. Infection is characterised by primary, secondary and tertiary stages. The incubation period is between 9-90 days

Answer 91

Primary features chancre - painless ulcer at the site of sexual contact local non-tender lymphadenopathy often not seen in women (the lesion may be on the cervix)

Answer 92

Secondary features - occurs 6-10 weeks after primary infection systemic symptoms: fevers, lymphadenopathy rash on trunk, palms and soles buccal 'snail track' ulcers (30%) condylomata lata (painless, warty lesions on the genitalia )

Answer 93

Tertiary features gummas (granulomatous lesions of the skin and bones) ascending aortic aneurysms general paralysis of the insane tabes dorsalis Argyll-Robertson pupil

Answer 94

Features of congenital syphilis blunted upper incisor teeth (Hutchinson's teeth), 'mulberry' molars rhagades (linear scars at the angle of the mouth) keratitis saber shins saddle nose deafness

Answer 95

Oral or topical metronidazole or topical clindamycin

Answer 96

Bacterial vaginosis (BV) describes an overgrowth of predominately anaerobic organisms such as Gardnerella vaginalis. This leads to a consequent fall in lactic acid producing aerobic lactobacilli resulting in a raised vaginal pH.

Answer 97

Amsel's criteria for diagnosis of BV - 3 of the following 4 points should be present thin, white homogenous discharge clue cells on microscopy: stippled vaginal epithelial cells vaginal pH > 4.5 positive whiff test (addition of potassium hydroxide results in fishy odour)

Answer 98

Management if the woman is asymptomatic, treatment is not usually required CKS e.g. picked up on a swab done for different reasons exceptions include if a woman is undergoing a termination of pregnancy

Answer 99

if symptomatic: oral metronidazole for 5-7 days CKS 70-80% initial cure rate relapse rate > 50% within 3 months a single oral dose of metronidazole 2g may be used if adherence may be an issue the BNF suggests topical metronidazole or topical clindamycin as alternatives

Answer 100

if pregnant CKS results in an increased risk of preterm labour, low birth weight and chorioamnionitis, late miscarriage it was previously taught that oral metronidazole should be avoided in the first trimester and topical clindamycin used instead. Recent guidelines however recommend that oral metronidazole is used throughout pregnancy if asymptomatic: discuss with the woman's obstetrician if treatment is indicated if symptomatic: either oral metronidazole for 5-7 days or topical treatment. The higher, stat dose of metronidazole mentioned above is not recommended

Answer 101

Trichomonas vaginalis is a highly motile, flagellated protozoan parasite. Trichomoniasis is a sexually transmitted infection (STI).

Answer 102

Features vaginal discharge: offensive, yellow/green, frothy vulvovaginitis strawberry cervix pH > 4.5 in men is usually asymptomatic but may cause urethritis

Answer 103

Investigation microscopy of a wet mount shows motile trophozoites

Answer 104

Management oral metronidazole for 5-7 days, although the BNF also supports the use of a one-off dose of 2g metronidazole

Answer 105

Non-gonococcal urethritis (NGU, sometimes referred to as non-specific urethritis) is a term used to describe the presence of urethritis when a gonococcal bacteria are not identifiable or the initial swab. A typical case would be a male who presented to a GUM clinic with a purulent urethral discharge and dysuria. A swab would be taken in clinic, microscopy performed which showed neutrophils but no Gram-negative diplococci (i.e. no evidence of gonorrhoea). Clearly, this patient requires immediate treatment prior to waiting for the Chlamydia test to come back and hence an initial diagnosis of NGU is made.

Answer 106

No cause is found in around half of cases. Possible causative organisms include: Chlamydia trachomatis most common cause Mycoplasma genitalium thought to cause more symptoms than Chlamydia less common causes Ureaplasma urealyticum Trichomonas vaginalis Escherichia coli

Answer 107

Management contact tracing the BNF and British Association for Sexual Health and HIV (BASHH) both recommend either oral azithromycin or doxycycline

Answer 108

Chancroid is a tropical disease caused by Haemophilus ducreyi. It causes painful genital ulcers associated with unilateral, painful inguinal lymph node enlargement. The ulcers typically have a sharply defined, ragged, undermined border.

Answer 109

There are two strains of the herpes simplex virus (HSV) in humans: HSV-1 and HSV-2. Whilst it was previously thought HSV-1 accounted for oral lesions (cold sores) and HSV-2 for genital herpes it is now known there is considerable overlap

Answer 110

Features primary infection: may present with a severe gingivostomatitis cold sores painful genital ulceration

Answer 111

Management gingivostomatitis: oral aciclovir, chlorhexidine mouthwash cold sores: topical aciclovir although the evidence base for this is modest genital herpes: oral aciclovir. Some patients with frequent exacerbations may benefit from longer term aciclovir

Answer 112

Pregnancy elective caesarean section at term is advised if a primary attack of herpes occurs during pregnancy at greater than 28 weeks gestation women with recurrent herpes who are pregnant should be treated with suppressive therapy and be advised that the risk of transmission to their baby is low

Answer 113

Genital warts (also known as condylomata accuminata) are a common cause of attendance at genitourinary clinics. They are caused by the many varieties of the human papillomavirus HPV, especially types 6 & 11. It is now well established that HPV (primarily types 16,18 & 33) predisposes to cervical cancer. 6 & 11: causes genital warts 16 & 18: linked to a variety of cancers, most notably cervical cancer

Answer 114

Features small (2 - 5 mm) fleshy protuberances which are slightly pigmented may bleed or itch

Answer 115

Management topical podophyllum or cryotherapy are commonly used as first-line treatments depending on the location and type of lesion multiple, non-keratinised warts are generally best treated with topical agents solitary, keratinised warts respond better to cryotherapy imiquimod is a topical cream that is generally used second line genital warts are often resistant to treatment and recurrence is common although the majority of anogenital infections with HPV clear without intervention within 1-2 years

Answer 116

The UK has an HPV immunisation programme that provides protection against both the main oncogenic HPV strains (16 & 18) as well as the strains that commonly cause genital warts (6 & 11). The immunisation programme is aimed primarily at 12-13 years olds, both girls and boys but the vaccine is also offered to gay, bisexual, and other men who have sex with men (GBMSM) to protect against anal, throat and penile cancers.

Answer 117

All 12- and 13-year-olds (girls AND boys) in school Year 8 are offered the human papillomavirus (HPV) vaccine. the vaccine is normally given in school information given to parents and available on the NHS website make it clear that the child may receive the vaccine against parental wishes since September 2023 one dose is now given instead of two. This change followed evidence from large studies that one dose provided equivalent protection

Answer 118

Other groups eligible GBMSM under the age of 25 also receive 1-dose, offered through sexual health clinics eligible GBMSM aged 25 to 45 years receive a 2-dose schedule, offered through sexual health clinics eligible individuals who are immunosuppressed or those known to be HIV-positive receive a 3-dose schedule

Answer 119

Hepatitis B is a double-stranded DNA hepadnavirus and is spread through exposure to infected blood or body fluids, including vertical transmission from mother to child. The incubation period is 6-20 weeks.

Answer 120

The features of hepatitis B include fever, jaundice and elevated liver transaminases. Complications of hepatitis B infection chronic hepatitis (5-10%). 'Ground-glass' hepatocytes may be seen on light microscopy fulminant liver failure (1%) hepatocellular carcinoma glomerulonephritis polyarteritis nodosa cryoglobulinaemia

Answer 121

Immunisation against hepatitis B (please see the Greenbook link for more details) children born in the UK are now vaccinated as part of the routine immunisation schedule. This is given at 2, 3 and 4 months of age at risk groups who should be vaccinated include: healthcare workers, intravenous drug users, sex workers, close family contacts of an individual with hepatitis B, individuals receiving blood transfusions regularly, chronic kidney disease patients who may soon require renal replacement therapy, prisoners, chronic liver disease patients

Answer 122

Contains HBsAg adsorbed onto aluminium hydroxide adjuvant and is prepared from yeast cells using recombinant DNA technology 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

Answer 123

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

Answer 124

Anti-HBs level (mIU/ml) Response > 100 Indicates adequate response, no further testing required. Should still receive booster at 5 years 10 - 100 Suboptimal response - one additional vaccine dose should be given. If immunocompetent no further testing is required < 10 Non-responder. Test for current or past infection. Give further vaccine course (i.e. 3 doses again) with testing following. If still fails to respond then HBIG would be required for protection if exposed to the virus

Answer 125

Management of hepatitis B pegylated interferon-alpha used to be the only treatment available. It reduces viral replication in up to 30% of chronic carriers. A better response is predicted by being female, < 50 years old, low HBV DNA levels, non-Asian, HIV negative, high degree of inflammation on liver biopsy 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)

Answer 126

Hepatitis C is likely to become a significant public health problem in the UK in the next decade. It is thought around 200,000 people are chronically infected with the virus. At risk groups include intravenous drug users and patients who received a blood transfusion prior to 1991 (e.g. haemophiliacs).

Answer 127

hepatitis C is a RNA flavivirus incubation period: 6-9 weeks

Answer 128

Transmission the risk of transmission during a needle stick injury is about 2% the vertical transmission rate from mother to child is about 6%. The risk is higher if there is coexistent HIV breastfeeding is not contraindicated in mothers with hepatitis C the risk of transmitting the virus during sexual intercourse is probably less than 5% there is no vaccine for hepatitis C

Answer 129

After exposure to the hepatitis C virus only around 30% of patients will develop features such as: a transient rise in serum aminotransferases / jaundice fatigue arthralgia

Answer 130

Investigations 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 Outcome around 15-45% of patients will clear the virus after an acute infection (depending on their age and underlying health) and hence the majority (55-85%) will develop chronic hepatitis C

Answer 131

Chronic hepatitis C may be defined as the persistence of HCV RNA in the blood for 6 months. Potential complications of chronic hepatitis C rheumatological problems: arthralgia, arthritis eye problems: Sjogren's syndrome cirrhosis (5-20% of those with chronic disease) hepatocellular cancer cryoglobulinaemia: typically type II (mixed monoclonal and polyclonal) porphyria cutanea tarda (PCT): it is increasingly recognised that PCT may develop in patients with hepatitis C, especially if there are other factors such as alcohol abuse membranoproliferative glomerulonephritis

Answer 132

Management of chronic infection treatment depends on the viral genotype - this should be tested prior to treatment the management of hepatitis C has advanced rapidly in recent years resulting in clearance rates of around 95%. Interferon based treatments are no longer recommended the aim of treatment is sustained virological response (SVR), defined as undetectable serum HCV RNA six months after the end of therapy currently a combination of protease inhibitors (e.g. daclatasvir + sofosbuvir or sofosbuvir + simeprevir) with or without ribavirin are used

Answer 133

ribavirin - side-effects: haemolytic anaemia, cough. Women should not become pregnant within 6 months of stopping ribavirin as it is teratogenic

Answer 134

interferon alpha - side-effects: flu-like symptoms, depression, fatigue, leukopenia, thrombocytopenia

Answer 135

Hepatitis D is a single stranded RNA virus that is transmitted parenterally. It is an incomplete RNA virus that requires hepatitis B surface antigen to complete its replication and transmission cycle. It is transmitted in a similar fashion to hepatitis B (exchange of bodily fluids) and patients may be infected with hepatitis B and hepatitis D at the same time.

Answer 136

Hepatitis D terminology: Co-infection: Hepatitis B and Hepatitis D infection at the same time. Superinfection: A hepatitis B surface antigen positive patient subsequently develops a hepatitis D infection. Superinfection is associated with high risk of fulminant hepatitis, chronic hepatitis status and cirrhosis.

Answer 137

Diagnosis is made via reverse polymerase chain reaction of hepatitis D RNA. Interferon is currently used as treatment, but with a poor evidence base.

Answer 138

Hepatitis A is typically a benign, self-limiting disease, with a serious outcome being very rare. Overview incubation period: 2-4 weeks RNA picornavirus transmission is by faecal-oral spread, often in institutions doesn't cause chronic disease

Answer 139

Features flu-like prodrome abdominal pain: typically right upper quadrant tender hepatomegaly jaundice deranged liver function tests

Answer 140

Complications complications are rare and there is no increased risk of hepatocellular cancer

Answer 141

Immunisation an effective vaccine is available after the initial dose a booster dose should be given 6-12 months later

Answer 142

Who should be vaccinated? (Based on the Green book guidelines) people travelling to or going to reside in areas of high or intermediate prevalence, if aged > 1 year old people with chronic liver disease patients with haemophilia men who have sex with men injecting drug users individuals at occupational risk: laboratory worker; staff of large residential institutions; sewage workers; people who work with primates

Answer 143

RNA hepevirus spread by the faecal-oral route incubation period: 3-8 weeks

Answer 144

common in Central and South-East Asia, North and West Africa, and in Mexico causes a similar disease to hepatitis A, but carries a significant mortality (about 20%) during pregnancy

Answer 145

does not cause chronic disease or an increased risk of hepatocellular cancer a vaccine is currently in development, but is not yet in widespread use

Answer 146

HIV seroconversion is symptomatic in 60-80% of patients and typically presents as a glandular fever type illness. Increased symptomatic severity is associated with poorer long term prognosis. It typically occurs 3-12 weeks after infection

Answer 147

Features sore throat lymphadenopathy malaise, myalgia, arthralgia diarrhoea maculopapular rash mouth ulcers rarely meningoencephalitis

Answer 148

HIV antibodies may not be present in early infection, but most people develop antibodies to HIV at 4-6 weeks but 99% do by 3 months usually consists of both a screening ELISA (Enzyme Linked Immuno-Sorbent Assay) test and a confirmatory Western Blot Assay p24 antigen a viral core protein that appears early in the blood as the viral RNA levels rise usually positive from about 1 week to 3 - 4 weeks after infection with HIV combination tests (HIV p24 antigen and HIV antibody) are now standard for the diagnosis and screening of HIV if the combined test is positive it should be repeated to confirm the diagnosis some centres may also test the viral load (HIV RNA levels) if HIV is suspected at the same time

Answer 149

testing for HIV in asymptomatic patients should be done at 4 weeks after possible exposure after an initial negative result when testing for HIV in an asymptomatic patient, offer a repeat test at 12 weeks

Answer 150

Antiretroviral therapy (ART) involves a combination of at least three drugs, typically two nucleoside reverse transcriptase inhibitors (NRTI) and either a protease inhibitor (PI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI). This combination both decreases viral replication but also reduces the risk of viral resistance emerging Following the 2015 BHIVA guidelines it is now recommended that patients start ART as soon as they have been diagnosed with HIV, rather than waiting until a particular CD4 count, as was previously advocated.

Answer 151

Entry inhibitors maraviroc (binds to CCR5, preventing an interaction with gp41), enfuvirtide (binds to gp41, also known as a 'fusion inhibitor') prevent HIV-1 from entering and infecting immune cells

Answer 152

tenofovir: used in BHIVAs two recommended regime NRTI. Adverse effects include renal impairment and ostesoporosis zidovudine: anaemia, myopathy, black nails didanosine: pancreatitis

Answer 153

Non-nucleoside reverse transcriptase inhibitors (NNRTI) examples: nevirapine, efavirenz side-effects: P450 enzyme interaction (nevirapine induces), rashes

Answer 154

Protease inhibitors (PI) examples: indinavir, nelfinavir, ritonavir, saquinavir side-effects: diabetes, hyperlipidaemia, buffalo hump, central obesity, P450 enzyme inhibition indinavir: renal stones, asymptomatic hyperbilirubinaemia ritonavir: a potent inhibitor of the P450 system

Answer 155

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

Answer 156

Mode of delivery vaginal delivery is recommended if viral load is less than 50 copies/ml at 36 weeks, otherwise caesarian section is recommended a zidovudine infusion should be started four hours before beginning the caesarean section

Answer 157

Neonatal antiretroviral therapy zidovudine is usually administered orally to the neonate if maternal viral load is <50 copies/ml. Otherwise triple ART should be used. Therapy should be continued for 4-6 weeks.

Answer 158

Infant feeding in the UK all women should be advised not to breast feed

Answer 159

Diarrhoea is common in patients with HIV. This may be due to the effects of the virus itself (HIV enteritis) or opportunistic infections Possible causes Cryptosporidium + other protozoa (most common) Cytomegalovirus Mycobacterium avium intracellulare Giardia

Answer 160

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. Treatment is difficult, with the mainstay of management being supportive therapy

Answer 161

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

Answer 162

Kaposi's sarcoma caused by HHV-8 (human herpes virus 8) presents as purple papules or plaques on the skin or mucosa (e.g. gastrointestinal and respiratory tract) skin lesions may later ulcerate respiratory involvement may cause massive haemoptysis and pleural effusion radiotherapy + resection

Answer 163

Oesophageal candidiasis is the most common cause of oesophagitis in patients with HIV. It is generally seen in patients with a CD4 count of less than 100. Typical symptoms include dysphagia and odynophagia. Fluconazole and itraconazole are first-line treatments.

Answer 164

Toxoplasmosis accounts for around 50% of cerebral lesions in patients with HIV constitutional symptoms, headache, confusion, drowsiness CT: usually single or multiple ring enhancing lesions, mass effect may be seen management: sulfadiazine and pyrimethamine Thallium spect negative

Answer 165

Primary CNS lymphoma accounts for around 30% of cerebral lesions associated with the Epstein-Barr virus CT: single or multiple homogenous enhancing lesions treatment generally involves steroids (may significantly reduce tumour size), chemotherapy (e.g. methotrexate) + with or without whole brain irradiation. Surgical may be considered for lower grade tumours Thallium spect positive

Answer 166

Encephalitis may be due to CMV or HIV itself HSV encephalitis but is relatively rare in the context of HIV CT: oedematous brain

Answer 167

Cryptococcus most common fungal infection of CNS headache, fever, malaise, nausea/vomiting, seizures, focal neurological deficit

Answer 168

CSF high opening pressure elevated protein reduced glucose normally a lymphocyte predominance but in HIV white cell count many be normal India ink test positive

Answer 169

CT: meningeal enhancement, cerebral oedema meningitis is typical presentation but may occasionally cause a space-occupying lesion

Answer 170

Progressive multifocal leukoencephalopathy (PML) widespread demyelination due to infection of oligodendrocytes by JC virus (a polyoma DNA virus) symptoms, subacute onset : behavioural changes, speech, motor, visual impairment CT: single or multiple lesions, no mass effect, don't usually enhance. MRI is better - high-signal demyelinating white matter lesions are seen

Answer 171

AIDS dementia complex caused by HIV virus itself symptoms: behavioural changes, motor impairment CT: cortical and subcortical atrophy

Answer 172

Campylobacter is the commonest bacterial cause of infectious intestinal disease in the UK. The majority of cases are caused by the Gram-negative bacillus Campylobacter jejuni. It is spread by the faecal-oral route and has an incubation period of 1-6 days.

Answer 173

Features prodrome: headache malaise diarrhoea: often bloody abdominal pain: may mimic appendicitis

Answer 174

Management usually self-limiting the BNF advises treatment if severe or the patient is immunocompromised. Clinical Knowledge summaries also recommend antibiotics if severe symptoms (high fever, bloody diarrhoea, or more than eight stools per day) or symptoms have last more than one week the first-line antibiotic is clarithromycin ciprofloxacin is an alternative although the BNF states that 'Strains with decreased sensitivity to ciprofloxacin isolated frequently'

Answer 175

Complications Guillain-Barre syndrome may follow Campylobacter jejuni infections reactive arthritis septicaemia, endocarditis, arthritis

Answer 176

Cryptosporidiosis is the commonest protozoal cause of diarrhoea in the UK. Two species, Cryptosporidium hominis and Cryptosporidium parvum account for the majority cases. Cryptosporidiosis is more common in immunocompromised patients (e.g. HIV) and young children.

Answer 177

Features watery diarrhoea abdominal cramps fever in immunocompromised patients, the entire gastrointestinal tract may be affected resulting in complications such as sclerosing cholangitis and pancreatitis

Answer 178

Diagnosis stool: modified Ziehl-Neelsen stain (acid-fast stain) of the stool may reveal the characteristic red cysts of Cryptosporidium

Answer 179

Management is largely supportive for immunocompetent patients if the patient has HIV and is not on antiretroviral therapy then this should be started and often will be enough to resolve the infection nitazoxanide may be used for immunocompromised patients rifaximin is also sometimes used for immunocompromised patients/patients with severe disease

Answer 180

First episode: oral vancomycin Second or subsequent episode of infection: oral fidaxomicin

Answer 181

Travellers' diarrhoea may be defined as at least 3 loose to watery stools in 24 hours with or without one of more of abdominal cramps, fever, nausea, vomiting or blood in the stool. The most common cause is Escherichia coli.

Answer 182

Common amongst travellers Watery stools Abdominal cramps and nausea

Answer 183

Prolonged, non-bloody diarrhoea

Answer 184

Profuse, watery diarrhoea Severe dehydration resulting in weight loss Not common amongst travellers

Answer 185

Bloody diarrhoea Vomiting and abdominal pain

Answer 186

Severe vomiting Short incubation period

Answer 187

Two types of illness are seen vomiting within 6 hours, stereotypically due to rice diarrhoeal illness occurring after 6 hours

Answer 188

Gradual onset bloody diarrhoea, abdominal pain and tenderness which may last for several weeks

Answer 189

ncubation period 1-6 hrs: Staphylococcus aureus, Bacillus cereus* 12-48 hrs: Salmonella, Escherichia coli 48-72 hrs: Shigella, Campylobacter > 7 days: Giardiasis, Amoebiasis

Answer 190

Ciprofloxacin

Answer 191

Ciprofloxacin

Answer 192

Giardiasis is caused by the flagellate protozoan Giardia lamblia. It is spread by the faeco-oral route. Risk factors foreign travel swimming/drinking water from a river or lake male-male sexual contact

Answer 193

Features often asymptomatic non-bloody diarrhoea steatorrhoea bloating, abdominal pain lethargy flatulence weight loss malabsorption and lactose intolerance can occur

Answer 194

Investigations stool microscopy for trophozoite and cysts: sensitivity of around 65% stool antigen detection assay: greater sensitivity and faster turn-around time than conventional stool microscopy methods PCR assays are also being developed

Answer 195

Treatment is with metronidazole.

Answer 196

The Salmonella group contains many members, most of which cause diarrhoeal diseases. They are aerobic, Gram-negative rods which are not normally present as commensals in the gut. Typhoid and paratyphoid are caused by Salmonella typhi and Salmonella paratyphi (types A, B & C) respectively. They are often termed enteric fevers, producing systemic symptoms such as headache, fever, arthralgia.

Answer 197

Pathophysiology typhoid is transmitted via the faecal-oral route (also in contaminated food and water)

Answer 198

Features initially systemic upset as above relative bradycardia abdominal pain, distension constipation: although Salmonella is a recognised cause of diarrhoea, constipation is more common in typhoid rose spots: present on the trunk in 40% of patients, and are more common in paratyphoid

Answer 199

Possible complications include osteomyelitis (especially in sickle cell disease where Salmonella is one of the most common pathogens) GI bleed/perforation meningitis cholecystitis chronic carriage (1%, more likely if adult females)

Answer 200

Diagnosis Clinical history and stool culture viral PCR (polymerase chain reaction).

Answer 201

Salmonella infection has an incubation period of 6 - 72 hours and is often the result of contact with contaminated animal products, for example, unpasteurized eggs or milk. Unlike norovirus, salmonella gastroenteritis can cause bloody diarrhoea and patients often have a high fever.

Answer 202

Rotavirus gastroenteritis causes symptoms very similar to those of norovirus, but predominantly affects children under the age of 5 years.

Answer 203

E. coli infection, like Norovirus, causes vomiting and diarrhoea but has a longer incubation period (between 3-4 days but can be up to 10 days following pathogen exposure) and unlike Norovirus, E Coli infection commonly causes severe abdominal cramping and frequently causes bloody diarrhoea.

Answer 204

Resolution and Potential Complications The infection is self-limiting in immunocompetent patients and symptoms generally resolve within 72 hours Dehydration and electrolyte imbalances may arise as a result of vomiting and diarrhoea, leading to significant morbidity and mortality and patients should be managed supportively with rehydration and electrolyte supplementation where necessary.

Answer 205

Brucellosis is a zoonosis more common in the Middle East and in farmers, vets and abattoir workers. Four major species cause infection in humans: B. melitensis (sheep), B. abortus (cattle), B. canis and B. suis (pigs). Brucellosis has an incubation period 2 - 6 weeks.

Answer 206

Features non-specific: fever, malaise hepatosplenomegaly sacroiliitis: spinal tenderness may be seen complications: osteomyelitis, infective endocarditis, meningoencephalitis, orchitis leukopenia often seen

Answer 207

Diagnosis the Rose Bengal plate test can be used for screening but other tests are required to confirm the diagnosis Brucella serology is the best test for diagnosis blood and bone marrow cultures may be suitable in certain patients, but these tests are often negative

Answer 208

Management doxycycline and streptomycin

Answer 209

Cutaneous larva migrans is a dermatological condition prevalent in tropical and subtropical regions, largely attributable to cutaneous penetration and subsequent migration of nematode larvae, primarily from the Ancylostoma genus (e.g. Ancyclostoma braziliense). Typically, the transmission vectors are faecal-contaminated soil or sand, posing significant risks to individuals with a history of barefoot beach visits or direct soil contact.

Answer 210

The clinical presentation typically involves an intensely pruritic, 'creeping', serpiginous, erythematous cutaneous eruption that advances over time. Symptoms can last for weeks to months, potentially leading to secondary bacterial infection due to excessive scratching. Diagnosis is typically clinical, based on exposure history and characteristic skin manifestations.

Answer 211

Treatment options revolve around anthelmintic agents, such as ivermectin or albendazole. Topical therapy with thiabendazole can also be effective, although it's generally less preferred due to a lower efficacy rate and higher side effect profile.

Answer 212

Prevention strategies largely involve patient education about appropriate protective measures, particularly avoiding direct skin contact with potentially contaminated soil. Given the zoonotic nature of cutaneous larva migrans, public health measures for animal defecation control can also contribute to reducing the prevalence of this condition.

Answer 213

Dengue fever is a viral infection that can progress to viral haemorrhagic fever (other examples include yellow fever, Lassa fever, Ebola). Aetiology dengue virus is a RNA virus of the genus Flavivirus transmitted by the Aedes aegypti mosquito incubation period of 7 days

Answer 214

Patients with dengue fever can be classified as follows: dengue fever: without warning signs with warning signs severe dengue (dengue haemorrhagic fever)

Answer 215

'warning signs' include: abdominal pain hepatomegaly persistent vomiting clinical fluid accumulation (ascites, pleural effusion)

Answer 216

Dengue fever fever headache (often retro-orbital) myalgia, bone pain and arthralgia ('break-bone fever') pleuritic pain facial flushing (dengue) maculopapular rash haemorrhagic manifestations e.g. positive tourniquet test, petechiae, purpura/ecchymosis, epistaxis

Answer 217

Severe dengue (dengue haemorrhagic fever) this is a form of disseminated intravascular coagulation (DIC) resulting in: thrombocytopenia spontaneous bleeding around 20-30% of these patients go on to develop dengue shock syndrome (DSS)

Answer 218

Investigations typically blood results leukopenia, thrombocytopenia, raised aminotransferases diagnostic tests serology nucleic acid amplification tests for viral RNA NS1 antigen test

Answer 219

Treatment entirely symptomatic e.g. fluid resuscitation, blood transfusion etc no antivirals are currently available

Answer 220

Diphtheria is caused by the Gram positive bacterium Corynebacterium diphtheriae Pathophysiology releases an exotoxin encoded by a β-prophage exotoxin inhibits protein synthesis by catalyzing ADP-ribosylation of elongation factor EF-2

Answer 221

Diphtheria toxin commonly causes a 'diphtheric membrane' on tonsils caused by necrotic mucosal cells. Systemic distribution may produce necrosis of myocardial, neural and renal tissue Possible presentations recent visitors to Eastern Europe/Russia/Asia sore throat with a 'diphtheric membrane' - grey, pseudomembrane on the posterior pharyngeal wall bulky cervical lymphadenopathy may result in a 'bull neck' appearanace neuritis e.g. cranial nerves heart block

Answer 222

Investigations culture of throat swab: uses tellurite agar or Loeffler's media

Answer 223

Management intramuscular penicillin diphtheria antitoxin

Answer 224

Leishmaniasis is caused by the intracellular protozoa Leishmania, which are spread by the bites of sandflies. Cutaneous, mucocutaneous leishmaniasis and visceral forms are seen

Answer 225

Cutaneous leishmaniasis caused by Leishmania tropica or Leishmania mexicana crusted lesion at the site of bite there may be an underlying ulcer it is typically diagnosed by doing a punch biopsy from the edge of the lesion allowing for both histology and culture cutaneous leishmaniasis acquired in South or Central America merits treatment due to the risk of mucocutaneous leishmaniasis whereas disease acquired in Africa or India can be managed more conservatively

Answer 226

Mucocutaneous leishmaniasis caused by Leishmania braziliensis skin lesions may spread to involve mucosae of nose, pharynx etc

Answer 227

Visceral leishmaniasis (kala-azar) mostly caused by Leishmania donovani occurs in the Mediterranean, Asia, South America, Africa fever, sweats, rigors massive splenomegaly. hepatomegaly poor appetite*, weight loss occasionally patients may report increased appetite with paradoxical weight loss grey skin - 'kala-azar' means black sickness pancytopaenia secondary to hypersplenism the gold standard for diagnosis is bone marrow or splenic aspirate

Answer 228

Leptospirosis is caused by the spirochaete Leptospira interrogans (serogroup L. icterohaemorrhagiae), classically being spread by contact with infected rat urine. Epidemiology leptospirosis is commonly seen in questions referring to sewage workers, farmers, vets or people who work in an abattoir however, on an international level, leptospirosis is far more common in the tropics so should be considered in the returning traveller

Answer 229

The early phase is due to bacteraemia and lasts around a week may be mild or subclinical fever flu-like symptoms subconjunctival suffusion (redness)/haemorrhage

Answer 230

second immune phase may lead to more severe disease (Weil's disease) acute kidney injury (seen in 50% of patients) hepatitis: jaundice, hepatomegaly aseptic meningitis

Answer 231

Investigation serology: antibodies to Leptospira develop after about 7 days PCR culture growth may take several weeks so limits usefulness in diagnosis blood and CSF samples are generally positive for the first 10 days urine cultures become positive during the second week of illness

Answer 232

Management high-dose benzylpenicillin or doxycycline

Answer 233

Features general features of malaria: fever, headache, splenomegaly Plasmodium vivax/ovale: cyclical fever every 48 hours. Plasmodium malariae: cyclical fever every 72 hours Plasmodium malariae: is associated with nephrotic syndrome

Answer 234

Treatment in areas which are known to be chloroquine-sensitive then WHO recommend either an artemisinin-based combination therapy (ACT) or chloroquine in areas which are known to be chloroquine-resistant an ACT should be used ACTs should be avoided in pregnant women patients with ovale or vivax malaria should be given primaquine following acute treatment with chloroquine to destroy liver hypnozoites and prevent relapse

Answer 235

GI upset 1 - 2 days 7 days

Answer 236

Headache Contraindicated in epilepsy Taken weekly 1 week 4 weeks

Answer 237

Photosensitivity Oesophagitis 1 - 2 days 4 weeks

Answer 238

Dizziness Neuropsychiatric disturbance Contraindicated in epilepsy Taken weekly 2 - 3 weeks 4 weeks

Answer 239

1 week 4 weeks

Answer 240

chloroquine can be taken proguanil: folate supplementation (5mg od) should be given Malarone (atovaquone + proguanil): the BNF advises to avoid these drugs unless essential. If taken then folate supplementation should be given mefloquine: caution advised doxycycline is contraindicated

Answer 241

It is again advisable to avoid travel to malaria endemic regions with children if avoidable. However, if travel is essential then children should take malarial prophylaxis as they are more at risk of serious complications. diethyltoluamide (DEET) 20-50% has been shown to repel up to 100% of mosquitoes if used correctly. It can be used in children over 2 months of age* doxycycline is only licensed in the UK for children over the age of 12 years

Answer 242

Schistosomiasis, or bilharzia, is a parasitic flatworm infection. The three main species of schistosome are S. mansoni, S. japonicum and S. haematobium.

Answer 243

Acute manifestations may include: swimmers' itch acute schistosomiasis syndrome (Katayama fever) fever urticaria/angioedema arthralgia/myalgia cough diarrhoea eosinophilia

Answer 244

Schistosoma haematobium These worms deposit egg clusters (pseudopapillomas) in the bladder, causing inflammation. The calcification seen on x-ray is actually calcification of the egg clusters, not the bladder itself. Depending on the site of these pseudopapillomas in the bladder, they can cause an obstructive uropathy and kidney damage. This typically presents as a 'swimmer's itch' in patients who have recently returned from Africa. Schistosoma haematobium is a risk factor for squamous cell bladder cancer.

Answer 245

Features frequency haematuria bladder calcification

Answer 246

nvestigation for asymptomatic patients serum schistosome antibodies are generally preferred for symptomatic patients the gold standard for diagnosis is urine or stool microscopy looking for eggs Management single oral dose of praziquantel

Answer 247

These worms mature in the liver and then travel through the portal system to inhabit the distal colon. Their presence in the portal system can lead to progressive hepatomegaly and splenomegaly due to portal vein congestion. These species can also lead to complications of liver cirrhosis, variceal disease and cor pulmonale.

Answer 248

Schistosoma intercalatum and Schistosoma mekongi These are less prevalent than the other three forms, but are both attributed to intestinal schistosomiasis.

Answer 249

Strongyloides stercoralis is a human parasitic nematode worm. The larvae are present in soil and gain access to the body by penetrating the skin. Infection with Strongyloides stercoralis causes strongyloidiasis.

Answer 250

Features diarrhoea abdominal pain/bloating papulovesicular lesions where the skin has been penetrated by infective larvae e.g. soles of feet and buttocks larva currens: pruritic, linear, urticarial rash if the larvae migrate to the lungs a pneumonitis similar to Loeffler's syndrome may be triggered

Answer 251

Treatment ivermectin and albendazole are used

Answer 252

Two main form of this protozoal disease are recognised - African trypanosomiasis (sleeping sickness) and American trypanosomiasis (Chagas' disease).

Answer 253

Two forms of African trypanosomiasis, or sleeping sickness, are seen - Trypanosoma gambiense in West Africa and Trypanosoma rhodesiense in East Africa. Both types are spread by the tsetse fly. Trypanosoma rhodesiense tends to follow a more acute course. Clinical features include: Trypanosoma chancre - painless subcutaneous nodule at site of infection intermittent fever enlargement of posterior cervical lymph nodes later: central nervous system involvement e.g. somnolence, headaches, mood changes, meningoencephalitis

Answer 254

Management early disease: IV pentamidine or suramin later disease or central nervous system involvement: IV melarsoprol

Answer 255

American trypanosomiasis, or Chagas' disease, is caused by the protozoan Trypanosoma cruzi. The vast majority of patients (95%) are asymptomatic in the acute phase although a chagoma (an erythematous nodule at site of infection) and periorbital oedema are sometimes seen. Chronic Chagas' disease mainly affects the heart and gastrointestinal tract myocarditis may lead to dilated cardiomyopathy (with apical atophy) and arrhythmias gastrointestinal features includes megaoesophagus and megacolon causing dysphagia and constipation

Answer 256

Management 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

Answer 257

Zika is a mosquito-borne infection caused by Zika virus, a member of the genus flavivirus and family Flaviviridae. It was first isolated from a monkey in the Zika forest in Uganda in 1947. Transmission is usually via the bite of an infected Aedes mosquito, although a small number of cases of sexual transmission have been reported. There is increasing evidence of transmission via the placenta from mother to fetus.

Answer 258

The majority of people infected with Zika virus have no symptoms. For those with symptoms, Zika virus tends to cause a mild, short-lived (2 to 7 days) febrile disease. Signs and symptoms suggestive of Zika virus infection may include a combination of the following: fever rash arthralgia/arthritis conjunctivitis myalgia headache retro-orbital pain pruritus

Answer 259

Senior review if any warning signs are present (please see the Meningitis Research Foundation algorithm link for the full list). Examples include: rapidly progressive rash poor peripheral perfusion respiratory rate < 8 or > 30 / min or pulse rate < 40 or > 140 / min pH < 7.3 or WBC< 4 *109/L or lactate > 4 mmol/L GCS < 12 or a drop of 2 points poor response to fluid resuscitation

Answer 260

Lumbar puncture should be delayed in the following circumstances signs of severe sepsis or a rapidly evolving rash severe respiratory/cardiac compromise significant bleeding risk signs of raised intracranial pressure focal neurological signs papilloedema continuous or uncontrolled seizures GCS ≤ 12

Answer 261

IV antibiotics 3 months - 50 years: BNF recommends cefotaxime (or ceftriaxone) > 50 years: BNF recommends cefotaxime (or ceftriaxone) + amoxicillin (or ampicillin) for adults IV dexamethasone the BNF recommend to 'consider adjunctive treatment with dexamethasone (particularly if pneumococcal meningitis suspected in adults), preferably starting before or with first dose of antibacterial, but no later than 12 hours after starting antibacterial; avoid dexamethasone in septic shock, meningococcal septicaemia, or if immunocompromised, or in meningitis following surgery'

Answer 262

Initial empirical therapy aged < 3 months IVcefotaxime + amoxicillin (or ampicillin) Initial empirical therapy aged 3 months - 50 years IV cefotaxime (or ceftriaxone) Initial empirical therapy aged > 50 years IV cefotaxime (or ceftriaxone) + amoxicillin (or ampicillin) Meningococcal meningitis IV benzylpenicillin or cefotaxime (or ceftriaxone) Pneumococcal meningitis IV cefotaxime (or ceftriaxone) Meningitis caused by Haemophilus influenzae IV cefotaxime (or ceftriaxone) Meningitis caused by Listeria IV amoxicillin (or ampicillin) + gentamicin

Answer 263

If the patient has a history of immediate hypersensitivity reaction to penicillin or to cephalosporins the BNF recommends using chloramphenicol.

Answer 264

Prophylaxis needs to be offered to households and close contacts of patients affected with meningococcal meningitis. Prophylaxis should also be offered to people who have been exposed to respiratory secretion, regardless of the closeness of contact. The risk to contacts is highest in the first 7 days but persists for at least 4 weeks.

Answer 265

people who have been exposed to a patient with confirmed bacterial meningitis should be given prophylactic antibiotics if they have close contact within the 7 days before onset oral ciprofloxacin or rifampicin may be used. The Health Protection Agency (HPA) guidelines now state that whilst either may be used ciprofloxacin is the drug of choice as it is widely available and only requires one dose meningococcal vaccination should be offered to close contacts when serotype results are available, including booster doses to those who had the vaccine in infancy for pneumococcal meningitis, no prophylaxis is generally needed. There are however exceptions to this. If a cluster of cases of pneumococcal meningitis occurs the HPA have a protocol for offering close contacts antibiotic prophylaxis. Please see the link for more details

Answer 266

Generally speaking hypochlorite (chlorine in oxidation state +1) is recommend for the management of body fluid spillage. It is often used in the granular or powder form which is then spread over the affected area. Chlorine-releasing agents can be a hazard especially if used in large volumes in confined spaces or if mixed with urine. Ensuring adequate ventilation to the area is therefore important. Other points personal protective equipment (plastic aprons, gloves, mask, eye protection) is recommended for staff cleaning up body fluids mops should not be used

Answer 267

Suppression of MRSA from a carrier once identified 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

Answer 268

Mumps is a caused by RNA paramyxovirus and tends to occur in winter and spring Spread by droplets respiratory tract epithelial cells → parotid glands → other tissues infective 7 days before and 9 days after parotid swelling starts incubation period = 14-21 days

Answer 269

Clinical features fever malaise, muscular pain parotitis ('earache', 'pain on eating'): unilateral initially then becomes bilateral in 70%

Answer 270

Management rest paracetamol for high fever/discomfort notifiable disease

Answer 271

omplications orchitis - uncommon in pre-pubertal males but occurs in around 25-35% of post-pubertal males. Typically occurs four or five days after the start of parotitis hearing loss - usually unilateral and transient meningoencephalitis pancreatitis

Answer 272

Orf is generally a condition found in sheep and goats although it can be transmitted to humans. It is caused by the parapox virus.

Answer 273

In animals 'scabby' lesions around the mouth and nose

Answer 274

n humans generally affects the hands and arms initially small, raised, red-blue papules later may increase in size to 2-3 cm and become flat-topped and haemorrhagic

Answer 275

Be aware that the virus can affect an unborn baby in the first 20 weeks of pregnancy. If a woman is exposed early in pregnancy (before 20 weeks) she should seek prompt advice from whoever is giving her antenatal care as maternal IgM and IgG will need to be checked. It is spread by the respiratory route and a person is infectious 3 to 5 days before the appearance of the rash. Children are no longer infectious once the rash appears and there is no specific treatment.

Answer 276

Features prodrome: headache, fever, agitation hydrophobia: water-provoking muscle spasms hypersalivation Negri bodies: cytoplasmic inclusion bodies found in infected neurons

Answer 277

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: 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

Answer 278

Rubella, also known as German measles, is a viral infection caused by the togavirus. Following the introduction of the MMR vaccine, it is now very rare (typically less than 5 cases in the UK per year). If contracted during pregnancy there is a risk of congenital rubella syndrome

Answer 279

Basics outbreaks more common around winter and spring the incubation period is 14-21 days individuals are infectious from 7 days before symptoms appear to 4 days after the onset of the rash

Answer 280

Features prodrome, e.g. low-grade fever rash: maculopapular, initially on the face before spreading to the whole body, usually fades by the 3-5 day lymphadenopathy: suboccipital and postauricular

Answer 281

Complications arthritis thrombocytopaenia encephalitis myocarditis

Answer 282

Following a splenectomy patients are particularly at risk from pneumococcus, Haemophilus, meningococcus and Capnocytophaga canimorsus* infections

Answer 283

Vaccination if elective, should be done 2 weeks prior to operation Hib, meningitis A & C annual influenza vaccination pneumococcal vaccine every 5 years

Answer 284

Antibiotic prophylaxis penicillin V: unfortunately clear guidelines do not exist of how long antibiotic prophylaxis should be continued. It is generally accepted though that penicillin should be continued for at least 2 years and at least until the patient is 16 years of age, although the majority of patients are usually put on antibiotic prophylaxis for life

Answer 285

Post-splenectomy changes Platelets will rise first (therefore in ITP, transufsion should be given after splenic artery clamped) Blood film will change over following weeks, Howell-Jolly bodies will appear Other blood film changes include target cells and Pappenheimer bodies Increased risk of post-splenectomy sepsis, therefore prophylactic antibiotics and pneumococcal vaccine should be given.

Answer 286

Sulfonamides are a class of drug that work by inhibiting dihydropteroate synthetase. Antibiotic sulfonamides: sulfamethoxazole + co-trimoxazole is a combination of sulfamethoxazole + trimethoprim that is used in the management of Pneumocystis jiroveci pneumonia sulfadiazine sulfisoxazole There are also examples of non-antibiotic sulfonamides: sulfasalazine sulfonylureas

Answer 287

Adverse effects of co-trimoxazole include: hyperkalaemia headache rash (including Steven-Johnson Syndrome)

Answer 288

Examples doxycycline tetracycline Mechanism of action protein synthesis inhibitors binds to 30S subunit blocking binding of aminoacyl-tRNA Mechanism of resistance increased efflux of the bacteria by plasmid-encoded transport pumps, ribosomal protection

Answer 289

Notable adverse effects discolouration of teeth: therefore should not be used in children < 12 years of age photosensitivity angioedema black hairy tongue

Answer 290

Mechanism of action interferes with DNA synthesis by inhibiting dihydrofolate reductase may, therefore, interact with methotrexate, which also inhibits dihydrofolate reductase

Answer 291

Adverse effects myelosuppression transient rise in creatinine: trimethoprim competitively inhibits the tubular secretion of creatinine resulting in a temporary increase which reverses upon stopping the drug trimethoprim blocks the ENaC channel in the distal nephron, causing a hyperkalaemic distal RTA (type 4). It also inhibits creatinine secretion, often leading to an increase in creatinine by around 40 points (but not necessarily causing AKI)

Answer 292

Metronidazole is a type of antibiotic that works by forming reactive cytotoxic metabolites inside the bacteria. Adverse effects disulfiram-like reaction with alcohol increases the anticoagulant effect of warfarin

Answer 293

Wounds less than 6 hours old, non-penetrating with negligible tissue damage

Answer 294

puncture-type injuries acquired in a contaminated environment e.g. gardening injuries wounds containing foreign bodies compound fractures wounds or burns with systemic sepsis certain animal bites and scratches

Answer 295

heavy contamination with material likely to contain tetanus spores e.g. soil, manure wounds or burns that show extensive devitalised tissue wounds or burns that require surgical intervention

Answer 296

Patient has had a full course of tetanus vaccines, with the last dose < 10 years ago no vaccine nor tetanus immunoglobulin is required, regardless of the wound severity

Answer 297

Patient has had a full course of tetanus vaccines, with the last dose > 10 years ago if tetanus prone wound: reinforcing dose of vaccine high-risk wounds (e.g. compound fractures, delayed surgical intervention, significant degree of devitalised tissue): reinforcing dose of vaccine + tetanus immunoglobulin

Answer 298

If vaccination history is incomplete or unknown reinforcing dose of vaccine, regardless of the wound severity for tetanus prone and high-risk wounds: reinforcing dose of vaccine + tetanus immunoglobulin

Answer 299

BCG measles, mumps, rubella (MMR) influenza (intranasal) oral rotavirus oral polio yellow fever oral typhoid

Answer 300

rabies hepatitis A influenza (intramuscular)

Answer 301

tetanus diphtheria pertussis

Answer 302

pneumococcus (conjugate) haemophilus (conjugate) meningococcus (conjugate) hepatitis B human papillomavirus