The human immunodeficiency virus (HIV) was discovered in the United States of America
(USA) among gay young men over three decades ago. Since that time, HIV has
spread to other parts of the world. Although it was once believed that Acquired Immune
Deficiency Syndrome (AIDS) was a disease of the poor, HIV is now prevalent in
many countries in all continents of the world. HIV infection causes immuno-suppression.
Because of immuno-suppression, the life of an individual who is HIV positive is characterised
by frequent illnesses which in many cases would have been warded off by the
immune system had the patient been healthy and HIV negative [1]. These illnesses
which are ushered in by immune-suppression due to HIV infection are called opportunistic
infections.
Antiretroviral therapy (ART) is used to treat HIV patients. ART suppresses the manifestations
of opportunistic infections. Besides, manifestations of HIV infection like weight
loss, change in hair texture and anaemia disappear once a patient is put on ART. Antiretrovirals
(ARVs) are now available in many countries of the world including Malawi.
Antiretroviral therapy is now a source of hope for the sick since it has improved the
survival of HIV patients. Without doubt, HIV is an unnecessary evil which is the curse
and plague of the twentieth century and beyond.
In this thesis we introduce a mathematical model for estimating HIV incidence from
cross-sectional sero-prevalence data. Besides, we describe the patterns of occurrence of
Kaposi sarcoma, non-Hodgkin lymphoma, esophageal cancer, eye cancer, breast cancer,
cervical cancer and all other cancers combined in the population of Blantyre district of
Malawi during 1996 - 2005, and predict the cancer burden for 2015 in the area. Three
papers constitute this thesis. In Paper I, a mathematical model for estimating HIVincidence from HIV sero-prevalence data is introduced and applied to Malawi data. In
Paper II, statistical models are used to determine the risk factors of early sexual debut
among men and women in Malawi. In Paper III, a description of the patterns of occurrence
of Kaposi sarcoma, oesophageal cancer, non-Hodgkin lymphoma, eye cancer,
breast cancer, cervical cancer and all other cancers combined in Blantyre, Malawi during
1996-2005 is given. Besides, cancer incidence trends during the same period are analyzed
and projections of cancer burden and standardized incidence rates of cancer for 2015 are
made using statistical models. Subsections 1.1 through 1.6 are the background to the
thesis. Subsection 1.7 is the rationale of the thesis. Subsection 1.8 explains the logical
connection of papers in this thesis. Section 2 presents the aims of this thesis. Section 3
is a description of the methods used in each of the three papers of this thesis. Section
4 gives a summary of the results. Section 5 is the discussion of the results. Section 6 is
the conclusion section of the thesis.