Corynebacterium diphtheriae biovar gravis detected – a question on our National Immunization Program
Corynebacterium diphtheriae biovar gravis causing death of a 5 years old child within 4 hours of hospital admission.
We already had diagnosed three different cases of diphtheria in Nepal from two different places when a fourth case presented to us. We had a female patient of 5 years who was referred from Janakpur by a pediatrician with a clinical diagnosis of diphtheria/ Infectious mononucleosis to our hospital (TUTH). The patient had a history of fever, sore throat for a week which progressed to development of bull neck, nasopharyngeal membrane and probably laryngeal membrane as she had stridor as well.
The pediatrician at TUTH diagnosed her as a case of Diphtheria and called us for collection of her sample. We collected the nasopharyngeal membrane and nasal swab with the help of resident and faculty of department of ENT. Then we performed gram stain and cultured the sample on Tellurite blood agar. Gram stain revealed pleomorphic, gram variable irregularly staining bacilli with polar bodies. The culture plate after an incubation of 24 hours at 37 degree Celsius revealed black colonies with greyish-white halo. Albert stain of the colonies showed bacilli with metachromatic granules. The culture plate was further incubated for 7 days which revealed ‘daisy head colonies’ which is a textbook rule for the diagnosis of Corynebacterium diphtheriae biovar gravis. The diagnosis was further established by others biochemical tests.
In the meantime, the patient was given diphtheria antitoxin after sample collection. But she died within 4 hours of hospital admission.
Corynebacterium diphtheriae biovar gravis is a strain that causes sever disease and rapid death as in this case. This strain may leads to epidemic outbreak. So, concerned body including us should be alert and our National immunization program which provide only three dose of DPT should be updated to five dose according to international guidelines.