Improving Diagnostic Ability and Assessing Prevalence of Schistosomiasis in Lusaka, Zambia 公开

Livingston, Paul Donald (2012)

Permanent URL: https://etd.library.emory.edu/concern/etds/bv73c091j?locale=zh
Published

Abstract



Background:
Of the 207 million cases of schistosomiasis worldwide, 90% are in Africa,
causing hundreds of thousands of deaths annually. Urogenital schistosomiasis (Schistosoma
haematobium) has been implicated as a cofactor affecting HIV-1 transmission in many countries
of sub-Saharan Africa through the creation of lesions, bleeding and other genital abnormalities.
Yet in Zambia, a country experiencing high prevalence of both HIV-1 (13.5%) and
schistosomiasis (estimates of 10-40%), few studies have examined prevalence of active
schistosomiasis in a population of HIV+ and HIV- urban men and women.

Methods:
Participants from the Zambia Emory HIV Research Project heterosexual cohort were
included: HIV+ men and women who had tested positive for schistosomiasis antibodies (n=68)
and HIV+ and HIV- men and women who came over the period of one month (n=99). Egg
excretion was tested utilizing urine filtration and Kato-Katz fecal smear analysis. Plasma
samples were analyzed through enzyme linked immunosorbent assays (ELISA) and Western blot
for antibodies and to distinguish between schistosome species. Bivariate tests for association
were conducted and a multivariate logistic regression model constructed to predict presence of
active schistosomiasis infection.

Results:
21% of HIV+ individuals, selected with positive ELISA serologies, had active excretion
of schistosome eggs, 19.1% positive for S. haematobium and 7.4 % positive for S. mansoni. In
comparison, 13% of unselected HIV+ and HIV- men and women had active excretion of
schistosome eggs with 10 % positive for S. haematobium. Logistic regression produced a model
predictive of active schistosomiasis infection (AUROC=0.80) that contained variables for age,
high ELISA antibody titer (>50), water contact as a child, positive Western blot result for S.
haematobium, years in Lusaka and A. lumbricoides positivity.

Discussion:
This study shows significant prevalence of active infection in both HIV+ and HIV-
Zambians and the need to conduct routine parasitological testing and treatment in countries
coendemic for HIV-1 and schistosomiasis. In developing countries, efforts need to be made to
provide praziquantel and train laboratory technicians in better diagnostic methods. Future
research should examine how male genital schistosomiasis affects HIV-1 transmission and
utilize urine reagent strips to test larger numbers of people in high transmission areas of Zambia.

Table of Contents


TABLE OF CONTENTS

CHAPTER 1: INTRODUCTION AND BACKGROUND 1

Definitions of Terms/Acronyms 5

CHAPTER 2: LITERATURE REVIEW

The Lifecycle of Bilharzia/Snail Fever 6

Schistosomiasis as a Genital Condition 7

Diagnosing Schistosomiasis 8

Treating Schistosomiasis 9

Schistosomiasis in Zambia 10

HIV-1 and Schistosomiasis 12

Poverty and Socio-determinants of Infection 15

The Role of Dams 16

Criticisms of the Literature 18

CHAPTER 3: METHODS AND RESULTS

Methods 20

Study Background 20

Sample Population 21

Research Design 22

Procedures 22

Treatment 25

Antibody Testing 26

Questionnaires 27

Data Analysis 28

Limitations and Delimitations 29

Results 35

CHAPTER 4: DISCUSSION, CONCLUSIONS, RECOMMENDATIONS

Discussion 41

Conclusions/Implications 43

Recommendations 46

About this Master's Thesis

Rights statement
  • Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.
School
Department
Degree
Submission
Language
  • English
Research field
关键词
Committee Chair / Thesis Advisor
Partnering Agencies
最新修改

Primary PDF

Supplemental Files