5.1 Laboratory analysis
All laboratory analyses, except TB cultures, were performed at Adama Regional Laboratory. CD4 cell counts were analyzed using BD FACSCalibur cytometer (Becton Dickinson, San Jose, CA). Sputum and FNA samples were analyzed with direct smear microscopy using Ziehl-Neelsen staining and Xpert MTB/RIF (Cepheid, Sunnyvale, CA) for polymerase chain reaction. Liquid cultures for TB were performed at International Clinical Laboratories, Addis Ababa, using a BACTEC MGIT 960 (BD Diagnostics, Franklin Lakes, NJ). Plasma HIV-RNA levels were determined using Abbott Real- Time HIV-1 assay (Abbott Molecular Inc., Des Plaines, IL) with a detection limit of 40 copies/ml. External quality assurance of the regional laboratory is regularly performed by the Center for Disease Control and Prevention (Atlanta, GA).
Study participant Characteristics
Study participants were recruited from Adama, Dhera, Geda, Modjo and Wolenchiti health centers taking ART and selected according to eligibility criteria. The minimum age included in the study was 18 years and the maximum age was 69 years
old. The mean, median and mode of participant age was 34, 32 and 30 years of age respectively. Forty five percent of the participants age was between 20-29 years old and minimum category was observed in
<20 years old with 1.6 percent. Sex distribution of the study participant was 41% male and 59% female participants. most of the study participants (41%) was married but widowed participant represent only 10 % of the participant. With regard to baseline viral load in which the measurement was taken when the study participants enrolled in to the study, 13% of them were with plasma viral load less than 10,000 copies/µl. plasma viral load was suppressed in 72% of individuals taking different regimen of ART treatment. The median HIV-1 plasma viral load in the untreated cohort was log 5.3111 copies/ml. Nine percent of participant complete higher education while 36% of them were illiterate. Study participants nutritional status was also assessed by the study. Six participants (2.46%) were classified as having acute malnutrition while 71(29.2%) Participants classified as having moderate malnutrition and the rest166 (68.3%) were classified as normal. Baseline CD4 count was determined at the beginning of the study. Based on the data 140(57.6% ) of the participants have BCD4 count of
<200 cells/µl, 77(31.7%) have BCD4 count
200-350 cells/µl and 26(10.7%) have BCD4 count of >350 cells/µl. Tuberculosis disease screened among participants before enrollment and 189(77.8%) were positive for MTB by AFB light microscopy smearing and culture (MGIT and LJ). Viral rebound was observed in 16.5% of study participant. The Proportion of patients having PVL suppressed after taking ART was 72.4%. study participant contributed 94 person-year of follow up. Incident rate of plasma viral load suppression was 21.8%.
At the time or recruitment, 16.6% of female participants and 7% of male participants had BPVL less than 10,000 copies/µl. while 83.3% of female and 92.9%of male participants hade BPVL of >10,000 copies/µl. The mean and median baseline plasma viral load of study participants was 4.03×105 cells/µl and 2.03×105 cells/µl.
Interaction between explanatory variables with the response variable was analyzed by using cross tab features of SPSS, IBM Inc. Base line PVL status of a patient did not showed significant interaction with event of interest with χ2 value 2.33(p-value .127). Other variables which did not show up includes age of the patient χ2 value of 4.44
(p-value .488), Marital status χ2 value of
6.75 (p-value .081), occupation χ2 value of
.383 (p-value .826), education status χ2 value of 1.13 (p-value.770), MUAC χ2 value of .253 (p-v alue .881), BTB with χ2 value of 1.15 (p-value .283).
Significant interaction or association with Plasma viral load suppression were observed in sex χ2 value of 5.06 (p-value 0.024), BMI with 0.003, BCD4, χ2 value of 10.98
(p-value 0.004) and ART Treatment regimen with χ2 value of 14.23 (p-value .0.027)
Comparison between different categories for survival
Survival distribution for different age group reveals that there was no significant difference between different age group and other variables in the study in terms of the time to reach suppressed plasma viral load with log rank test score of χ2 value 0.860.
Estimated median time to PVL suppression was 181days (CI: 140.5-221.4) with the age group of 30-39years having minimum time to achieve suppression with 92 days (CI: 60.1-123.8) and the maximum time required to reach the level was age group between 50-59 years.
Significantly different survival distribution curve was observed between different categories of marriage in the study participants. The maximum median time for PVL suppression was observed in unmarried participants with 183 days (CI: 181.7- 184.315). The minimum median time registered in divorced participant category with estimated median time of 92 days (CI: 91.06-92.93
Significant survival curve difference (log rank test: χ2 value of 8.84 and p-value of 0.012) was observed in HIV patients with different baseline CD4 count. Median survival time for patients with <200 cells/µl measured 182 days (CI: 160.80-203.19), 181
days (142.39-219.60) for BCD4 200-350
cells/µl, 174 days (CI: 133.40-214.59) and
174 days (CI: 133.40-214.59).
Forward factor selection method (for identifying synergistic effect of variables on response variables) was used to identify factors that are significantly affect the median time. Cox-proportional hazard regression method was used to estimate the magnitude of each variable. Variables with p-value of ≤0.05 were included in the model and selected as variables to fit a model that best explain the variance in the equation. Variables identified as significant in this study was marital status with p-value 0.023 and baseline CD4 with p-value 0.023. Educational status (p-value 0.404), MUAC (p- value 0.407), BMI(p-value 0.335) and BTB(p-value 0.257).