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Patients diagnosed with malaria can suffer from other bacterial or
protozoal diseases as either super-infections or co-infections. These infections can be
severe and sometimes even life-threatening. These associated infections are more common in
patients with P. falciparum malaria (with or without complications), elderly,
pregnant women and immunocompromised patients. Further, in most parts of the world where
malaria is rampant, so many other infectious diseases are also prevalent, sometimes
resulting in co-infection rather than super-infection.
Malarial infection has depressant effect on the immune system.
Acute malarial parasitemia has a profound immuno suppressant effect, probably through the
activation of suppressor T cells. In an malaria endemic area, young children may suffer
from severe infections (viral like measles or bacterial) due to this
immunosuppression.
In addition, complicated falciparum
malaria can be a predisposing factor for certain specific infections. For example,
patients with cerebral malaria, altered consciousness or generalised seizures can develop
aspiration bronchopneumonia; patients with indwelling catheters may develop urinary tract
infection; patients with prolonged coma may develop decubitus ulcers that may get
infected; infection can also occur through the sites of intravenous cannulation. Patients
with malaria, in addition, can also have other infections that are prevalent in the
community e.g., pneumonia, bacillary dysentery, amebiasis, typhoid, tuberculosis etc. Gram
negative septicemia can occur without any evident focus and may also lead to Gram negative
shock.
Manifestations of secondary infections
and of malaria can overlap. Fever, cough, diarrhoea and dysentery can be seen in malaria,
making the identification of the secondary infections rather difficult.
Persistence of fever even after 48-72
hours of antimalarial treatment and reduction in parasitemia should raise the possibility
of secondary infections. One should not change the antimalarial therapy or add newer
antimalarial drugs (considering resistance) in these cases , instead should look for these
secondary infections.
Presence of tachypnoea, productive
sputum, lateral chest pain related to breathing, bronchial breath sounds, crackles would
suggest the possibility of a pneumonia and a chest x ray should be done.
Neck stiffness and other signs of
meningeal irritation would suggest meningitis. A CT scan and lumbar puncture for CSF
examination should be considered.
In places where tuberculosis is common,
malaria may bring the patient to the doctor and underlying tuberculosis can create
confusion if undiagnosed. Tubercular meningitis can masquerade as cerebral malaria if the
patient gets malaria as a co-infection.
Total and differential count, urine
analysis and culture, stool examination and culture, blood culture, chest X ray, Widal
test etc. should be done as required.
Neutrophilic leukocytosis in the absence
of severe falciparum malaria may indicate bacterial infection. Mild albuminuria and pyuria
may be seen in malaria with high fever, however significant changes may indicate urinary
infection. Stool examination may confirm bacillary or amebic colitis. Widal test may show
positive titres up to 1:320 dilution even in malaria. Positive titre for both S. typhi
and S. parathyphi A or S. paratyphi B usually indicates anamnestic
reaction. A diagnostic titre of more than 1:640, however, confirms enteric fever.
All cases of secondary infection should
be treated with appropriate antibiotics. In case of septicemic shock, a third generation
cephalosporin with or without an aminoglycoside should be used.
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