Trends in illicit drugs based on the analysis of seizures from the Tanzania mainland drugs market.

This study aimed at investigating the pattern of confiscated illegal drugs in the Tanzania mainland drug market from 2011 to 2016. The samples used in this study were seized by the police force and other law enforcement agents and were analysed at the Government Chemist Laboratory Authority, GCLA. A total of 90,366 samples weighing 17961.5 Kg were seized and analysed during the six years, an average of 15,061 samples corresponding to 2993.6 Kg per year. The overall results indicated cannabis to be the leading drug in terms of number of cases, number of samples and weights with 51.02%, 60.50% and 56.90%, respectively, but from 2011 to 2015 heroin had the highest percentage of both number of cases and samples by 58.46% and 55.91% of all seizures, respectively followed by cannabis. In terms of weight, heroin accounted for 67.55% and 26.32% in 2011 and 2012, respectively, whereas, the rest of the years' percentage weights were between 0.50 and 6.00% of the total seizures. The trend indicated a steady decrease in heroin seizures over the six years and an increased cannabis seizure. In 2016 cannabis was 78.28% and 80.89% of the total number of cases and samples, respectively. The results also indicated the decrease of cocaine cases and a significant increase in the amount khat. The year 2016 recorded the highest number of cases and number of samples with a total of 1212 and 48,440, respectively, which resulted from the increase in cannabis seizures by 72.28% and 80.89% of the total number of cases and samples, respectively, as compared to 2015. The second and third highest years were 2013 and 2014, respectively. The least was 2011 with 3493 samples. The trend also indicated heroin seizures were highest in 2011 (62.04%), 2014 (75.31%) and 2015 (79.26%) whereas cocaine seizures kept on decreasing gradually from 31.12% in 2011 to 0.05% in 2016. Khat () had the highest weight in 2014 and 2016 and ranked second after cannabis with 43.63% of the total weight during 2011-2016 period. Benzodiazepines and amphetamine type stimulants (ATS) accounted the least in terms of number of cases and number of samples.