Zoologists detect drug resistance in skin-disfiguring Leishmania parasite, propose new treatment approaches

PESHAWAR, Apr 09 (APP):Scientists at University of Peshawar’s Institute of Zoological Sciences have detected signs of resistance in the skin-disfiguring Leishmania parasite to antimonial drugs, the primary first-line treatment for all forms of leishmaniasis.

Leishmaniasis is a neglected tropical disease that manifests in three forms: cutaneous (causing skin ulcers), mucocutaneous (along with skin ulcers also affecting delicate lining of oral and other luminous cavities) and visceral (affecting internal soft organs primarily liver, spleen and bone marrow).

According to the World Health Organization, an estimated 600,000 to one million new cases of cutaneous leishmaniasis (CL) occur globally each year, although only around 200,000 cases are officially reported.

In 2023, approximately 91% of reported cases were concentrated in just eleven countries, including Pakistan, which recorded an estimated 59,255 cases. However, the actual number is believed to be significantly higher.

“Findings from several M. Phil and an ongoing PhD research study have identified early signs of resistance in Leishmania, a genus of parasitic protozoa responsible for leish maniasis,” said Dr. Qaisar Jamal, lecturer at IZS and incharge of the Laboratory of Parasitology and Tropical Diseases at the University of Peshawar.

He explained that meglumine antimoniate, marketed as Glucantime, is a pentavalent antimonial compound and remains the primary treatment used to treat the Leishmania causing the disease.

The findings have raised concerns about emerging resistance, highlighting the urgent need for further research on the parasite’s biology, as well as the development of new treatment options for this severe skin disease, which affects thousands of people particularly in Khyber Pakhtunkhwa and the merged districts.

Dr. Jamal noted that the Laboratory of Parasitology and Tropical Diseases serves as a key facility for culturing Leishmania through in vitro testing. The parasite is studied in its promastigote morphological stage after being collected from infected samples.

The laboratory also acts as a repository, supplying Leishmania cultures to research centers across the country. It is currently collaborating with the Peshawar University’s Chemistry Department on research involving nanoparticle-based and plant derived preparations targeting the parasite.

He added that two PhD students are currently conducting research under his supervision on drug resistance as well as culturing Leishmania, while four students have already completed their M.Phil studies in this field.

The growing resistance of the parasite requires further investigation and the development of new drugs.

“If resistance continues to increase, meglumine antimoniate may gradually lose its effectiveness, as it has lost in other parts of the world,” Dr. Jamal warned.

Discussing the causes of resistance, he said, “it is partly a natural consequence of prolonged drug use over several decades. Additionally, inconsistent treatment among patients contributes to resistance, as many fail to complete their therapy”. Shortages of imported drugs at healthcare facilities further aggravate the problem.

Dr. Jamal also highlighted the role of climate change, noting that it affects the population and ecology of sand flies, the vectors that host and transmit Leishmania to humans through bites.

He explained that longer summer seasons due to global warming are increasing the active period of sand flies, which typically become dormant during winter.

The zoologist urged the government to take this issue of public health seriously and invest in the development of indigenous medicines for treating leishmaniasis.

He recommended forming a national consortium comprising healthcare professionals, zoologists, researchers and entomologists to develop innovative and sustainable treatment and preventive strategies for the disease, which continues to affect thousands across the country.