The pathogenesis of the two illnesses has been evaluated at molecular level and certain similarities have been found. It has been shown that increased TNF-α levels predispose to both diseases  and both illnesses are acted upon by a Type 1 T cell response which targets intracellular pathogens .
The ulcer on the arm of the patient probably occurred after a bite by the sand-fly which inoculated the leishmania organism in it. Secondary contamination of the ulcer with B.pseudomallei due to the high environmental prevalence of the organism could have caused the melioidosis infection. Diabetes mellitus would have predisposed the patient to acquiring the infection as well .
The presence of hepatosplenomegaly in the patient initially provoked the possibility of ‘kala azar’ or visceral leishmaniasis but since the patient was not very ill, was antibody negative and since she recovered with antibiotics to melioidosis, this assumption was discarded later [10, 11].
The diagnosis of melioidosis is often elusive but can be made through antibody assays and direct isolation via cultures . The positive antibody titer and culture in this patient, together, pins the diagnosis of melioidosis.
Melioidosis treatment has two arms, the intensive phase and eradication phase. During the intensive phase, ceftazidime, meropenem or imipenem is used for a duration of 2–4 weeks. Co-trimoxazole may be added if the patient is poorly responding. The eradication phase uses co-trimoxazole or doxycycline up to a period of six months .
Cutaneous leishmaniasis can be treated with local cauterization or intra-lesional administration of sodium stibogluconate .
Since there was only one case report of a co-infection with both these illnesses and because there are set guidelines for the management of them individually, we treated the two infections separately.
As both melioidosis and leishmaniasis are emerging infectious diseases in Sri Lanka, physicians should have a high clinical suspicion when dealing with patients with pyrexia of unknown origin, especially when they’re from areas where the diseases are more prevalent.