BHUBANESWAR: The first-ever community-based study on haemoglobinopathies among particularly vulnerable tribal groups (PVTGs) in malaria-endemic areas of Odisha revealed a high prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency, sickle cell anaemia and thalassaemia associated with malaria.
Among the 75 enlisted PVTGs in the country, the highest 13 - Juang, Bondo, Didayi, Langia Saora, Saora, Kutia Kondho, Dongoria Kondho, Paudi Bhuyan, Birhor, Chuktia Bhunjia, Kharia, Lodha and Mankidia - with a population of around 0.25 million are found in 12 districts of the state.
The study found a moderate to high prevalence of G6PD deficiency in nine out of 13 PVTGs and 57.4 per cent of the G6PD deficiency individuals were found to be positive for malaria indicating high transmission and high annual parasite index (API) in the 12 districts.
The prevalence of G6PD and malaria was more prevalent among men than women. Out of 13 PVTGs, G6PD deficiency was found to be prevalent among nine tribes with the lowest in Didayi (1.1 per cent) and the highest in Hill Kharia (10.4 per cent). Beta-thalassaemia gene was detected only in Paudi Bhuyan PVTG. The prevalence of malaria was high in Kutia Kondho, Dongoria, Kondho, and Paudi Bhuyan.
The study also detected a significantly low level of haemoglobin (Hb) among G6PD-deficient individuals. People with G6PD deficiency and infected with malaria had significantly low Hb levels.
Of the 1,461 samples including 779 from women with a mean age of 32 years, screened from 697 households, 3.4 per cent (50 people) were diagnosed with sickle cell anaemia. A sequence analysis revealed the presence of Arab-Indian haplotype in all the cases. Sickle cell anaemia was found in eight tribes while thalassemia was prevalent in five tribes.
Odisha with around four per cent of the total population contributes almost 40 per cent of the annual malaria burden of the country, mostly reported from hilly forested areas. Since G6PD deficiency is common in malaria-endemic areas, WHO had recommended G6PD testing before giving PQ. But G6PD testing is rarely done in Odisha, the study said.
“Despite the therapeutic advantages of primaquine (PQ) drug in malaria control, its wider use is restricted as it increases toxicity among people with G6PD deficiency. The diagnosis and management of G6PD deficiency are important for malaria control,” said a researcher associated with the study.
The study published in the recent issue of Malaria journal was conducted by Regional Medical Research Centre (RMRC), in association with the School of Biotechnology, KIIT University and Scheduled Castes and Scheduled Tribes Research and Training Institute.