A population-based study of Kaposi Sarcoma-associated herpesvirus seropositivity in Uganda using principal components analysis

BACKGROUND: Kaposi sarcoma-associated herpesvirus (KSHV) seropositivity is associated with sexual, environmental, and socioeconomic exposures. Whether these characteristics are independent risk factors is uncertain because of reliance on selected high-risk or hospital-based populations and incomplete adjustment for confounding. Therefore, we evaluated risk factors for KSHV seropositivity in a population-based study in Uganda using principal components analysis (PCA). METHODS: The study population comprised 2,681 individuals randomly selected from a nationally-representative population-based HIV/AIDS sero-behavioral survey conducted in 2004/05. Questionnaire and laboratory data (97 variables) were transformed into a smaller set of uncorrelated variables using PCA. Multivariable logistic regression models were fitted to estimate odds ratios and 95% confidence intervals for the association between components and KSHV seropositivity. RESULTS: Data were reduced to three principal components (PCs) labeled as Sexual behavioral, Socioeconomic, and Knowledge PCs. In crude analysis, KSHV seropositivity was associated with the Knowledge (p(trend) = 0.012) and Socioeconomic components (p(trend) = 0.0001), but not with the Sexual-behavioral component (p(trend) = 0.066). KSHV seropositivity was associated with the Socioeconomic PC (p(trend) = 0.037), but not with the Sexual-behavioral and Knowledge PCs, in the models including PCs, age, gender and geographic region. CONCLUSIONS: Our results fit with the view that in Uganda socioeconomic characteristic may influence KSHV seropositivity. Conversely, the results fit with the interpretation that in Uganda sexual-behavioral characteristics, if relevant, contribute minimally

A population-based study of Kaposi Sarcoma-associated herpesvirus seropositivity in Uganda using principal components analysis

Abstract Background Kaposi sarcoma-associated herpesvirus (KSHV) seropositivity is associated with sexual, environmental, and socioeconomic exposures. Whether these characteristics are independent risk factors is uncertain because of reliance on selected high-risk or hospital-based populations and incomplete adjustment for confounding. Therefore, we evaluated risk factors for KSHV seropositivity in a population-based study in Uganda using principal components analysis (PCA). Methods The study population comprised 2,681 individuals randomly selected from a nationally-representative population-based HIV/AIDS sero-behavioral survey conducted in 2004/05. Questionnaire and laboratory data (97 variables) were transformed into a smaller set of uncorrelated variables using PCA. Multivariable logistic regression models were fitted to estimate odds ratios and 95% confidence intervals for the association between components and KSHV seropositivity. Results Data were reduced to three principal components (PCs) labeled as Sexual behavioral, Socioeconomic, and Knowledge PCs. In crude analysis, KSHV seropositivity was associated with the Knowledge (p trend  = 0.012) and Socioeconomic components (p trend  = 0.0001), but not with the Sexual-behavioral component (p trend  = 0.066). KSHV seropositivity was associated with the Socioeconomic PC (p trend  = 0.037), but not with the Sexual-behavioral and Knowledge PCs, in the models including PCs, age, gender and geographic region. Conclusions Our results fit with the view that in Uganda socioeconomic characteristic may influence KSHV seropositivity. Conversely, the results fit with the interpretation that in Uganda sexual-behavioral characteristics, if relevant, contribute minimally.http://deepblue.lib.umich.edu/bitstream/2027.42/112399/1/13027_2012_Article_423.pd

Human Herpesvirus 8 Seropositivity Among Sexually Active Adults in Uganda

Sexual transmission of human herpesvirus 8 (HHV8) has been implicated among homosexual men, but the evidence for sexual transmission among heterosexual individuals is controversial. We investigated the role of sexual transmission of HHV8 in a nationally representative sample in Uganda, where HHV8 infection is endemic and transmitted mostly during childhood.The study population was a subset of participants (n = 2681) from a population-based HIV/AIDS serobehavioral survey of adults aged 15-59 years conducted in 2004/2005. High risk for sexual transmission was assessed by questionnaire and serological testing for HIV and herpes simplex virus 2. Anti-HHV8 antibodies were measured using two enzyme immunoassays targeting synthetic peptides from the K8.1 and orf65 viral genes. The current study was restricted to 2288 sexually active adults. ORs and 95% CIs for HHV8 seropositivity were estimated by fitting logistic regression models with a random intercept using MPLUS and SAS software.The weighted prevalence of HHV8 seropositivity was 56.2%, based on 1302 seropositive individuals, and it increased significantly with age (P(trend)<0.0001). In analyses adjusting for age, sex, geography, education, and HIV status, HHV8 seropositivity was positively associated with reporting two versus one marital union (OR:1.52, 95% CI: 1.17-1.97) and each unit increase in the number of children born (OR: 1.04, 95% CI: 1.00-1.08), and was inversely associated with ever having used a condom (OR: 0.64, 95% CI: 0.45-0.89). HHV8 seropositivity was not associated with HIV (P = 0.660) or with herpes simplex virus 2 (P = 0.732) seropositivity. Other sexual variables, including lifetime number of sexual partners or having had at least one sexually transmitted disease, and socioeconomic variables were unrelated to HHV8 seropositivity.Our findings are compatible with the conclusion that sexual transmission of HHV8 in Uganda, if it occurs, is weak

EVALUATING HIV TESTING ALGORITHMS FOR RESEARCH, DIAGNOSIS AND SURVEILLANCE

The objective of the study was to evaluate the validity of the HIV testing algorithms used at St. Mary's Hospital Lacor (Gulu district, North Uganda) for research, diagnosis and surveillance. The validity of a new testing algorithm based on rapid tests for research and diagnosis was determined by testing 560 samples from the antenatal clinic at Lacor Hospital and using the old ELISA algorithm as a gold standard. The validity of a new testing algorithm for HIV surveillance, assuming the previously used Wellcozyme as a gold standard, was determined using 360 samples from the same antenatal clinic. Using the old ELISA algorithm as a gold standard, the new rapid test algorithm for diagnosis and research has a sensitivity of 90.6% and a specificity of 98.8%, yielding an accuracy rate in correctly classifying the results of 96.6%. In comparison to the Wellcozyme kit, the new testing algorithm for HIV surveillance has a sensitivity of 77.3% and a specificity of 96.8%, with no difference in the prevalence of HIV infection between the two testing schemes.The two testing algorithms evaluated in this study show good performances according to the purposes of their use. It is important that before full introduction of new HIV testing kits and algorithms into a setting, field evaluation studies are carried out to determine their validity

Hepatitis B infection is highly endemic in Uganda: findings from a national serosurvey

Background: Infant immunization against hepatitis B began in Uganda in 2002. Objective: To determine the baseline prevalence of hepatitis B virus (HBV) infection and explore risk factors. Methods: A hepatitis B prevalence study was nested in the 2005 national HIV/AIDS serobehavioural survey. Demographic characteristics and risk factors were explored by questionnaire. One third of blood specimens (n=5875) from adults aged 15 to 59 years were tested for hepatitis B core antibodies (HBcAb); positive specimens were tested for hepatitis B surface antigen (HBsAg). Results: HBcAb was present in 52.3% (95% CI: 51.0-53.6) of adults, and HBsAg in 10.3% (9.5-11.1). By 15-19 years of age, 40.0% had been infected with HBV. Prevalence of both markers was significantly higher across northern Uganda, in rural areas, among the poor and least educated, and in uncircumcised men. Other independent predictors of infection were age, ethnic group, occupation, number of sex partners, and HIV and HSV-2 status. Conclusion: Hepatitis B virus infection is highly endemic in Uganda, with transmission occurring in childhood and adulthood. More than 1.4 million adults are chronically infected and some communities disproportionately affected. The hepatitis B infant immunization programme should be sustained and catch-up vaccination considered for older children

Human herpesvirus 8 load and progression of AIDS-related Kaposi sarcoma lesions

Introduction—Human herpesvirus 8 (HHV8) is necessary for Kaposi sarcoma (KS) to develop, but whether peripheral blood viral load is a marker of KS burden (total number of KS lesions), KS progression (the rate of eruption of new KS lesions), or both is unclear. We investigated these relationships in persons with AIDS. Methods—Newly diagnosed patients with AIDS-related KS attending Mulago Hospital, in Kampala, Uganda, were assessed for KS burden and progression by questionnaire and medical examination. Venous blood samples were taken for HHV8 load measurements by PCR. Associations were examined with odds ratio (OR) and 95% confidence intervals (CI) from logistic regression models and with t-tests. Results—Among 74 patients (59% men), median age was 34.5 years (interquartile range [IQR], 28.5-41). HHV8 DNA was detected in 93% and quantified in 77% patients. Median virus load was 3.8 logs10/106 peripheral blood cells (IQR 3.4-5.0) and was higher in men than women (4.4 vs. 3.8 logs; p=0.04), in patients with faster (>20 lesions per year) than slower rate of KS lesion eruption (4.5 vs. 3.6 logs; pmedian [20] KS lesions) than fewer KS lesions (4.4 vs. 4.0 logs; p=0.16). HHV8 load was unrelated to CD4 lymphocyte count (p=0.23). Conclusions—We show significant association of HHV8 load in peripheral blood with rate of eruption of KS lesions, but not with total lesion count. Our results suggest that viral load increases concurrently with development of new KS lesions