Thesis (MSc)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Substance abuse is an imminent danger on the health of both substance users and nonusers.
In general, abuse of psychoactive substances is associated with high risk behaviour,
mortality and morbidity. The drug use cycle involves inextricably intertwined variants
such as production, trading and usage of both licit and illicit addictive substances. The
dynamics of substance use involve initiation, addiction, rehabilitation/treatment and quitting/
recovery. In response to supply and abuse of monster drugs, control strategies such
as law enforcement and rehabilitation have been stepped up to reduce access to drugs by
targeting drug kingpins and harm reduction respectively. In this thesis, we model the factors
affecting the prevalence of substance abuse, the effect of drug lords on the prevalence
of substance abuse, and the impact of substance abuse on the prevalence of HIV/AIDS.
We formulate mathematical models based on systems of autonomous differential equations
describing the dynamics of the sub- populations involved in the drug using cycle.
We examine the effects of amelioration, rehabilitation/treatment and re- initiation on the
prevalence of substance abuse. Our results suggest that, recruitment into rehabilitation
and amelioration in the presence of quitting for light users reduce the prevalence of substance
abuse; re-initiation and amelioration without quitting for light users increase the
prevalence of substance abuse. Our assessment of the impact of drug lords and the effect
of law enforcement on drug epidemics shows that, the presence of drug lords seriously
constraints the efforts to reduce substance abuse since they increase access to drugs. However,
law enforcement if stepped up in response to the population of drug lords, greatly
reduces the prevalence of substance abuse. Given the associated influence of drugs on high
risky behaviour, as a cofactor for sexually transmitted infections, we assess the influence of
substance abuse on the prevalence of Human Immunodeficiency Virus (HIV). Our results
show that dissemination of information regarding HIV and drug use reduces HIV prevalence
whereas, there is faster spread of the epidemic and high prevalence with increased
sexual contact. / AFRIKAANSE OPSOMMING: Dwelmmisbruik is ’n dreigende gevaar vir die gesondheid van beide dwelm gebruikers en
nie-gebruikers. In die algemeen, word die misbruik van psigoaktiewe dwelms verbind met
hoë risiko gedrag, mortaliteit en morbiditeit. Die dwelmgebruikskringloop behels onlosmaaklik
vervlegde variante soos vervaardiging, handel en gebruik van beide wettige en
onwettige verslawende middels. Die dinamika van dwelms behels aanvang, verslawing, rehabilitasie/
behandeling en staking/herstel. In reaksie op die misbruik en verskaffing van
monster dwelms, is beheer strategieë soos wetstoepassing en rehabilitasie verskerp, om
die toegang tot dwelms te verminder, deur onderskeidelik te fokus op dwelmspilfigure en
skadebeperking. Die belangrikste doel van hierdie verhandeling is om die faktore te modelleer
wat die voorkoms van dwelmmisbruik beïnvloed, die uitwerking van dwelmbase op
die voorkoms van dwelmmisbruik, en die trefkrag van dwelmmisbruik op die voorkoms van
MIV / VIGS. Ons formuleer wiskundige modelle gegrond op stelsels van outonome differensiaalvergelykings,
wat die dinamika beskryf van die sub-bevolkinge wat in die dwelmgebruikskringloop
betrokke is. Ons ondersoek die effekte van verbetering, rehabilitasie/behandeling
en heraanvang op die voorkoms van dwelmmisbruik. Ons resultate dui dat,
werwing tot rehabilitasie en verbetering in die teenwoordigheid van stakende tydelike verbruikers,
die voorkoms van dwelmmisbruik verminder; heraanvang en verbetering sonder
dat tydelike verbruikers staak, verhoog die voorkoms van dwelmmisbruik. Ons raming van
die invloed van dwelmbase en die uitwerking van wetstoepassing op dwelm-epidemies toon
dat, die teenwoordigheid van dwelmbase belemmer grotendeels die pogings om dwelmmisbruik
te verminder, aangesien hulle toegang tot dwelms verhoog. Nietemin, as die wetstoepassing
verskerp word in reaksie op die dwelmbaasbevolking, word die voorkoms van
dwelmmisbruik aansienlik verminder. Gegewe die gepaardgaande invloed van dwelms op
hoë risiko gedrag as ’n kofaktor vir seksueel oordraagbare infeksies, beraam ons die invloed
van dwelmmisbruik op die voorkoms van die Menslike Immunogebreksvirus (MIV). Ons
resultate toon dat inligtingverspreiding rakende MIV en dwelmgebruik, MIV-voorkoms
verlaag, terwyl daar ’n vinniger verspreiding van die epidemie en hoë voorkoms is, met
verhoogde seksuele kontak.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/17935 |
| Date | 12 1900 |
| Creators | Njagarah, Hatson John Boscoh |
| Contributors | Farai, Nyabadza, Stellenbosch University. Faculty of Science. Dept. of Mathematical Sciences. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 104 p. : ill. |
| Rights | Stellenbosch University. |
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