Question 16#

A 27-year-old male presents with malaise, pyrexia, lymphadenopathy and a maculopapular rash. The Monospot test is negative. Given a history of high-risk sexual behaviour you are asked to exclude a HIV seroconversion illness.

What is the most appropriate investigation? 

A. Antibodies to HIV-2

Correct Answer C: 

HIV: seroconversion:

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.

Features:

• Sore throat
• Lymphadenopathy
• Malaise, myalgia, arthralgia
• Diarrhoea
• Maculopapular rash
• Mouth ulcers
• Rarely meningoencephalitis

Diagnosis:

• Antibodies to HIV may not be present
• HIV PCR and p24 antigen tests can confirm diagnosis

Question 17#

A 47-year-old lady is referred by her GP with a two day history of fever and headache. She is normally fit and well and has no past medical history of note. On examination you note nuchal rigidity. Investigations show the following:

• Serum glucose 4.9 mmol/l

Lumbar puncture reveals:

• Opening pressure 14 cmCSF
• Appearance Cloudy
• Glucose 1.7 mmol/l
• Protein 1.9 g/l
• White cells 900 / mm³ (90% polymorphs)

What is the most likely infective agent? 

A. Streptococcus pneumoniae

Correct Answer A: The CSF results are consistent with bacterial meningitis (low glucose, high protein, high polymorphs). In this age group Streptococcus pneumoniae and Neisseria meningitidis are the most common causes of bacterial meningitis.

Meningitis: causes (infective agents):
0 - 3 months:

• Group B Streptococcus (most common cause in neonates)
• E. coli
• Listeria monocytogenes

3 months - 6 years:

• Neisseria meningitidis
• Streptococcus pneumoniae
• Haemophilus influenzae

6 years - 60 years:

• Neisseria meningitidis
• Streptococcus pneumoniae

> 60 years:

• Streptococcus pneumoniae
• Neisseria meningitidis
• Listeria monocytogenes

Immunosuppressed

• Listeria monocytogenes

Question 18#

A male child from a traveling community is diagnosed with measles.

Which one of the following complications is he at risk from in the immediate aftermath of the initial infection?

A. Arthritis

Correct Answer E: Subacute sclerosing panencephalitis is seen but develops 5-10 years following the illness. Pancreatitis and infertility may follow mumps infection.

Measles:

Overview:

• RNA paramyxovirus
• Spread by droplets
• Infective from prodrome until 5 days after rash starts
• Incubation period = 10-14 days

Features:

• Prodrome: irritable, conjunctivitis, fever
• Koplik spots (before rash): white spots ('grain of salt') on buccal mucosa
• Rash: starts behind ears then to whole body, discrete maculopapular rash becoming blotchy & confluent

Complications:

• Encephalitis: typically occurs 1-2 weeks following the onset of the illness)
• Subacute sclerosing panencephalitis: very rare, may present 5-10 years following the illness
• Febrile convulsions
• Pneumonia, tracheitis
• Keratoconjunctivitis, corneal ulceration
• Diarrhoea
• Increased incidence of appendicitis
• Myocarditis

Management of contacts:

• If a child not immunized against measles comes into contact with measles then MMR should be offered (vaccine-induced measles antibody develops more rapidly than that following natural infection)
• This should be given within 72 hours

Question 19#

A 34-year-old postman attends the Emergency Department following a dog bite to his right hand.

What is the most appropriate antibiotic therapy?

A. Metronidazole + amoxicillin

Correct Answer C: Animal bite - co-amoxiclav.

A combination of doxycycline and metronidazole is recommended in the BNF if the patient is penicillin allergic.

Animal bites Management:

• Cleanse wound
• Current BNF recommendation is co-amoxiclav
• If penicillin-allergic then doxycycline + metronidazole is recommended

Question 20#

You review a 14-year-old boy who has recently emigrated from Russia. He was involved in car accident two years ago and underwent an emergency splenectomy. Following this he takes penicillin V on a daily basis. He is unsure of his vaccination history.

Which organism is he particularly susceptible to?

A. Staphylococcus aureus

Correct Answer C: Penicillin V would protect him against Streptococcus pneumoniae but not Haemophilus influenzae due to the production of beta-lactamases by the organism.

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

Vaccination:

• If elective, should be done 2 weeks prior to operation
• Hib, meningitis A & C
• Annual influenza vaccination
• Pneumococcal vaccine every 5 years

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.

*usually from dog bites