Detection of Antiretroviral treatment failure among adult HIV-1 patients on anti-retroviral therapy for 12 +/- 3 months attending different Voluntary Counseling Testing and treatment centers in Khartoum state, Sudan


 Objective: Small number of people on antiretroviral therapy and their virological status in Sudan is lacking. This study aimed to determine the viral load for adult HIV-1 patients who were on antiretroviral therapy for 12+/- 3 months attending different Voluntary Counseling Testing and treatment centers (VCT/ART) in Khartoum state, Sudan.Results: out of 112 adult HIV-1 patients included in this study, only 17.9% (20/112) showed unsuppressed viral load (treatment failure). The majority of them from Omdurman VCT/ART center 80% (16/20), followed by Khartoum VCT/ART center 15% (3/20), Bahri VCT/ART center 5% (1/20) and non from Elban Gadeid VCT/ART center. All of them were on the first line of treatment. Most of them 30% (6/20) on 39-48 years old age group, the majority of them 55%(11/20) on stage 3 WHO clinical staging.

Sudan is one of the areas that enclosed by countries with higher rate of HIV infection. The prevalence was 1.6% in 2002 (2) . As indicated by UNAIDS 2011, the prevalence was diminished to 0.4% after South Sudan dissociation. In 2018 it was diminished to 0.2%. (3) In Sudan, 2018, adults living with HIV were 55000, among them, only 9000 (15%) were on antiretroviral therapy (ART) and no data about people living with HIV who have suppressed viral loads (3) In areas with satisfactory resources, research center estimations of CD4 + T cells and plasma HIV viral load are usually used to build up a patient's level of immunosuppression and the rate of destruction of the immune system, these are used to ascertain a patient's eligibility for treatment and also monitor disease progression (4) . In resource limited areas in which de cient settings to test CD4 + T cells and plasma HIV viral load, clinicians depend on the clinical parameters while assessing a patient's disease status.
HIV-1 viral load testing is an essential part of HIV-1 management in the world, both before and during antiretroviral therapy (5) . The amount of virus present in the plasma affects clinical decisions; therefore, accurate sensitive viral load assays are very important.
Monitoring HIV viral load in people living with HIV is essential to maintain effective individual antiretroviral therapy as well as monitoring progress toward achieving population targets for viral suppression (6) . It is an excellent predictor of survival to AIDS and death (7,8) with a better correlation and independent of CD4 count (9,10) . Viral loads exceeding 50 copies/ml always need further investigations, and > 1,000 copies/ml (> 3 log copies/ml) is considered to be the threshold for resistance testing (11,12) and in this case, the WHO recommends a con rmatory viral load measurement 3 months after the rst viral load and enhanced adherence support, with switch to second-line ART contingent upon a continued elevated viral load (13) .
Without drug resistance, HIV-positive patients should achieve viral suppression within 8-24 weeks after ART initiation (14,15) In 2014 the Joint United Nations Program on HIV and AIDS (UNAIDS) set a determined target known as the 90-90-90, that indicated that by 2020, 1) 90% of all HIV positive people will be diagnosed, 2) 90% of all those diagnosed will be on treatment and 3) 90% of those linked to care will be virally suppressed. (16) So this study aimed to estimate the viral load for adult HIV-1 patients who were on antiretroviral therapy All participants were provided with written informed consent for guarantees of approval and con dentiality and then data (age, sex, WHO clinical stage and ART type and initiation date) were collected from patient management records from VCT/ART centers.

Blood samples collection, HIV-1 detection and quanti cation
Six ml of blood samples were collected in Ethylene diamine tetraacetic acid (EDTA) blood collection tubes. Plasma were separated by centrifugation at 5000 rpm for 5 minutes and stored in multiple aliquots at -80° C until used On the day of analysis, the aliquots were thawed, vortex-mixed, and tested for antibodies detection speci c to HIV-1 using 4th generation ELISA kit (Fortress diagnostics, United Kingdom) according to manufacturer instructions.
The remaining plasma (one ml) were taken for HIV-1 RNA viral load quanti cation by multiplex real time PCR, Cepheid Xpert HIV-1 viral load plasma assay (Cepheid, Inc., Sunnyvale, CA), according to manufacturer instructions, which had sensitivity above 95% in treatment failure detection (17) Data Analysis Data were analyzed by SPSS program version 23, using frequencies and cross tab

Discussion
Viral load is the preferred treatment-monitoring approach for HIV-positive patients. In Sudan, Gene Xpert was approved by WHO and introduced as a tool for TB/ HIV-1 diagnosis and monitoring respectively. It is rapid and less complexity assay (18) The present study result was similar to many studies results that showed low number of unsuppressed viral load patients. As in study conducted in South Africa in 2018, the percentage of patients in the rst line of treatment with virological failure was 22% (19) . Also studies done in Ethiopia in 2019 (20) and Uganda in 2015 (21) the percentage was 11% although their HIV frequency is higher than Sudan.
Regarding sex status, the number of males were higher than females (58% versus 42%) in this study, which is similar to study done in Sudan in 2015 in which males were higher (22) , however it was dissimilar to the study done in Ethiopia in 2019 in which the females were higher in number (20) .
The most higher WHO clinical stage of HIV was stage 3 in this study, which is dissimilar to study done in India in 2019 in which the most common unsuppressed patients were in stage 1 (23) The virological failure was observed in the age group 39-48 years, which is similar to the nding of the study done in Ethiopia in which virological failure was observed among patients aged < 35 years (20) Most of patients 82.1% had suppressed viral load (non detectable copies/ ml and less than 40 copies/ ml) because viral load usually become not detected after 12 3 month successful treatment, while patients with unsuppressed viral load may need a good adherence, they may have metabolic problems or they may have drug resistance mutations. This nding put Sudan closer to the UNAIDS treatment target 2020 in which 90% of patients under treatment must have suppressed viral load.

Conclusion
Establishment of a good ART program, routine and regular patients follow up and improving adherence can decrease the virological failure and improve treatment outcome.

Limitations
The present study was the rst study done in Sudan, it does not cover all the patients on ART for 12 months +/-3 months attending ART/VCT centers. Also it covers only four centers out of eight centers in Khartoum state, Sudan, so the results does not re ect and represent the whole HIV-1 patients in the country. All participants were provided with written informed consent for guarantees of approval and con dentiality (Additional le 1).