B. Fungal Infections

 
1. Pneumocystis carinii pneumonia  

 
Source:                                Unknown  

 

Clinical presentation:    

 

Weeks of dry cough, shortness of breath, fever, night sweats, weight loss; chest pain unusual

May present with pneumothorax: all HIV+ve patients who are at risk (low CD4 count or previous AIDS diagnosis) presenting with pneumothorax should be treated for PCP  

 
Diagnosis:                               Bronchoscopic alveolar lavage or inhalation of nebulised 3% hypertonic saline (induced sputum); stain for Pneumocystis with Wright-Giemsa stain  

 
Other investigations: Chest X-ray: May be normal in 50% initially
Typically ‘bats wing’ pattern of interstitial shadowing

 
Arterial blood gases:  Not diagnostic but guides severity  

 
Exercise oximetry:     Patient pedals on fixed exercise bike while attached to arterial oximeter.
If SaO2 fall <90% = +ve, highly suggestive of PCP if no previous lung disease  

 
Blood tests:  CD4 count usually <200
Lactate dehydrogenase raised (non-specific)  

Treatment:     Septrin (1 part trimethoprim and 5 parts sulphamethoxazole) 3860mg bd. (orally or iv) for 14 days
Nausea very common: give anti-emetic routinely
Up to 20% develop rash – risk of Stevens-Johnson Syndrome

 
2nd line treatments    Clindamycin 600mg qds with
Primaquine 30mg o.d.  

Dapsone 100mg o.d. with
Trimethoprim 15mg/kg/d (dividedose)

Pentamidine 4mg/kg o.d. for 3 days
Then on alternate days for 14 days  
Give nebulised inhaled pentaimidin
600mg o.d for first 3 days also.                           
Toxic drug:   Renal failure
Pancreatitis
Hypoglycaemia
Hypocalcaemia
Hypotension  

 
Oxygen supplementation if arterial pO2 <10kPa

Prednisolone 40mg o.d. if arterial pO2 <8kPa followed by dose reduction according to treatment response. Continue PCP treatment until steroids have stopped  

 
Complications:                  Pneumothorax common: often bilateral

Respiratory failure: may require intubation and ventilation

 
Infectious risk to others: None from PCP; but consider TB: isolate patient until 3 sputums –ve for MTB  

 
Prevention:   

All patients with 

previous PCP
Another AIDS diagnosis or
 CD4<200  
Septrin 960mg daily or 3 times per week or
Dapsone 100mg o.d or
Pentamidine:  300mg nebulised & inhaled fortnightly
Or 4mg/kg iv monthly  

 
2. Cryptococcosis  

 

  
Source:                                 Cryptococcus neoformans  in bird faeces  

 
Clinical presentation:   Meningitis, fever, may present with space occupying brain lesion                                         
Occasionally presents with pneumonia like PCP
May present with skin eruption: multiple skin nodules with central depression  

 
Diagnosis:     

Cerebro-spinal fluid: 

 Indian ink stain for budding yeast
Culture +ve in 92-100%
Antigen test +ve in 91-100%  

 
Blood Culture +ve in 75%
Antigen test +ve in 75-99%  

 
Other investigations: 

Consider CT Brain before LP if suspect raised intracranial pressure or space occupying lesion

 
CSF   Clear
Protein raised                                             
Increased lymphocytes                  
Low Glucose

But may all be normal  

 
Blood:   CD4 usually<50  

 
Treatment:         

Amphotericin B: 0.25mg/kg iv on day1, increasing by day 4 to full dose of 1mg/kg/d for approximately 14 days

Mild cases only: consider fluconazole 400-800mg/d po  

 
Complications:     

Raised intracranial pressure (ICP)

 
Risk factors:   Opening pressure at LP >20cm CSF
Reduced level of consciousness
Large amounts of organism in CSF
Low CSK white cell count
Positive blood cultures  

 
If ICP raised may require daily LP to drain CSF or shunt  

 
Infectious risk to others: None  

 

Prevention:                       

   

Fluconazole 400mg o.d prevents recurrence  
3. Penicilliosis  

 

  
Source:                               Penicillium marnaffei in urine of bamboo rat  

 
Clinical presentation:   Fever, skin nodules with central depression which ulcerate and bleed, anaemia, hepatosplenomegaly, weight loss  

 
Diagnosis:       Culture: Skin: 54% +ve
Blood: 54% +ve
Bone marrow: 64% +ve
Other investigations:    

 

  
Treatment:       mphotericin B (see above)
Itraconazole  

 
Complications:     fatal if untreated  

 
Infectious risk to others: None  

 
Prevention:                            No data  

 
4. Candidiasis  

 
Source:                               Naturally lives on human skin  

 

Clinical presentation:    

 

Oral: 

 white patches esp. soft palate
General redness of mouth Pain  

 
Oesophageal:   

Pain in central chest on swallowing
Food sticks when swallowed
Regurgitation of food

Usually accompanied by oral lesions

 
Presentation with septicaemia or endocarditis, rare unless chronically neutropaenic  

 
Diagnosis:                         Usually clinical; oesophageal involvement may be confirmed by endoscopy. However, response to treatment usually taken as confirmation  

 
Other investigations:    Cultures not usually necessary for uncomplicated cases  

 
Treatment:                   Mild:   Nystatin or amphotericin B lozenges  
Severe Ketoconazole 200mg/d 5 days
Or another azole  
Infectious risk to others: None  

 
 Prevention:                    Prolonged use of azoles (>2 weeks) encourages resistant candida to emerge. Preventive therapy therefore not recommended