This fungal infection is caused by the fungus
Penicillium Marneffei. This is a dimorphic fungus
which exhibits thermal dimorphism. At 37oC it grows
as a yeast-like fungus and at 30oC or lower
temperatures it grows as a mould. It exits in nature
as mycelium but in tissues it forms round or oval
cells which divide by fission.
The mycelia/spores are thought to be found in soil
and bamboo rats. They are asymptomatic carriers of
the fungus. It can infect a normal host, as well as
immune-suppressed patients. But in normal hosts,
most of the time it is focal infection, and in
immune suppressed patients the infection is
disseminated. It is a major and most frequent
opportunistic pathogen.
It occurs along with chronic lung diseases like
tuberculosis, emphysema, bronchiectasis, immune
suppression i.e. HIV, corticosteroid therapy,
diabetes etc.
Clinical symptoms
The infection presents as a chronic progressive
disease. Like other fungal infections, starting from
lungs in the initial stages, the symptoms are very
mild and may be like flu. Later non-specific
symptoms of fever, malaise, loss of weight and
appetite, anemia appear. The patient's presentation
is similar to tuberculosis, showing lung and
lymph-nodes involvement with cavity, consolidation
and abscess formation.
From the lungs, through the blood, the infection
spreads to other organs of the body like skin, gut,
kidney, bones, joints and the reticuloendothelial
system. The presentation of symptoms depends on the
organ, system or the part involved. The patients
present with liver and spleen enlargement,
thrombocytopinea, generalized lymphadinopathy,
anaemia etc.. Many patients present with multiple
papular lesions on skin with central necrotic
umbilication.
The illness can be fatal if it is not treated
properly and aggressively.
Penicillium marneffei is easily seen by
direct microscopy and in the culture of infected
tissues by staining it with Giemsa staine.
Treatment -
This infection is treatable, but antifungal agents
have to be started as soon as the infection is
suspected.
The drug of choice is FUNGISOME™ the
Liposomal Amphotericin B.
In less serious cases where patients can take oral
medication - FUNGITRACE™ (Itraconazole)
should be given. Fluconazole is found to be less
effective than Itraconazole. Maintenance dose of
200mg daily of Itraconazole have to be continued for
long duration to prevent relapse in AIDS patients.
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