title: Strengthening HIV surveillance in the antiretroviral therapy era: rationale and design of a longitudinal study to monitor HIV prevalence and incidence in the uMgungundlovu District, KwaZulu-Natal, South Africa.
abstract: BACKGROUND
  South Africa has over 6,000,000 HIV infected individuals and the province of KwaZulu-Natal (KZN) is the most severely affected. As public health initiatives to better control the HIV epidemic are implemented, timely, detailed and robust surveillance data are needed to monitor, evaluate and inform the programmatic interventions and policies over time. We describe the rationale and design of the HIV Incidence Provincial Surveillance System (HIPSS) to monitor HIV prevalence and incidence.
  
  
  METHODS
  The household-based survey will include a sample of men and women from two sub-districts of the uMgungundlovu municipality (Vulindlela and the Greater Edendale) of KZN, South Africa. The study is designed as two sequential cross-sectional surveys of 10,000 randomly selected individuals aged 15-49 years to be conducted one year apart. From the cross sectional surveys, two sequential cohorts of HIV negative individuals aged 15-35 years will be followed-up one year later to measure the primary outcome of HIV incidence. Secondary outcomes include the laboratory measurements for pulmonary tuberculosis, sexually transmitted infections and evaluating tests for estimating population-level HIV incidence. Antiretroviral therapy (ART) access, HIV-1 RNA viral load, and CD4 cell counts in HIV positive individuals will assess the effectiveness of the HIV treatment cascade. Household and individual-level socio-demographic characteristics, exposure to HIV programmatic interventions and risk behaviours will be assessed as predictors of HIV incidence. The incidence rate ratio of the two cohorts will be calculated to quantify the change in HIV incidence between consecutive samples. In anticipation of better availability of population-level HIV prevention and treatment programmes leading to decreases in HIV incidence, the sample size provides 84% power to detect a reduction of 30% in the HIV incidence rate between surveys.
  
  
  CONCLUSIONS
  The results from HIPSS will provide critical data regarding HIV prevalence and incidence in this community and will establish whether HIV prevention and treatment efforts in a "real world", non-trial setting have an impact on HIV incidence at a population level. Importantly, the study design and methods will inform future methods for HIV surveillance.
authors.affiliation: Centre for the AIDS Programme of Research in South Africa (CAPRISA), Doris Duke Medical Research Institute, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, 2nd Floor, Private Bag 7, Congella, 4013, Durban, South Africa. Ayesha.Kharsany@caprisa.org.
authors.forename: Ayesha B M
authors.initials: AB
authors.lastname: Kharsany
authors.affiliation: Epicentre AIDs Risk Management (Pty) Limited, P O Box 3484, Paarl, 7620, Cape Town, South Africa. Cheriec@epicentre.org.za.
authors.forename: Cherie
authors.initials: C
authors.lastname: Cawood
authors.affiliation: Epicentre AIDs Risk Management (Pty) Limited, P O Box 3484, Paarl, 7620, Cape Town, South Africa. Davidk@epicentre.org.za.
authors.forename: David
authors.initials: D
authors.lastname: Khanyile
authors.affiliation: Centre for the AIDS Programme of Research in South Africa (CAPRISA), Doris Duke Medical Research Institute, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, 2nd Floor, Private Bag 7, Congella, 4013, Durban, South Africa. Anneke.Grobler@caprisa.org.
authors.forename: Anneke
authors.initials: A
authors.lastname: Grobler
authors.affiliation: Centre for the AIDS Programme of Research in South Africa (CAPRISA), Doris Duke Medical Research Institute, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, 2nd Floor, Private Bag 7, Congella, 4013, Durban, South Africa. Lyle.Mckinnon@caprisa.org.
authors.forename: Lyle R
authors.initials: LR
authors.lastname: Mckinnon
authors.affiliation: Centre for the AIDS Programme of Research in South Africa (CAPRISA), Doris Duke Medical Research Institute, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, 2nd Floor, Private Bag 7, Congella, 4013, Durban, South Africa. Natasha.Samsunder@caprisa.org.
authors.forename: Natasha
authors.initials: N
authors.lastname: Samsunder
authors.affiliation: Centre for the AIDS Programme of Research in South Africa (CAPRISA), Doris Duke Medical Research Institute, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, 2nd Floor, Private Bag 7, Congella, 4013, Durban, South Africa. Janet.Frohlich@caprisa.org.
authors.forename: Janet A
authors.initials: JA
authors.lastname: Frohlich
authors.affiliation: Centre for the AIDS Programme of Research in South Africa (CAPRISA), Doris Duke Medical Research Institute, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, 2nd Floor, Private Bag 7, Congella, 4013, Durban, South Africa. Quarraisha.AbdoolKarim@caprisa.org.
authors.forename: Quarraisha
authors.initials: Q
authors.lastname: Abdool Karim
authors.affiliation: Centre for HIV and STIs, National Institute for Communicable Diseases, National Health Laboratory Service (NICD/NHLS), Johannesburg, South Africa. adrianp@nicd.ac.za.
authors.forename: Adrian
authors.initials: A
authors.lastname: Puren
authors.affiliation: South African Centre for Epidemiological Modelling and Analysis (SACEMA), Stellenbosch, South Africa. alexwelte@sun.ac.za.
authors.forename: Alex
authors.initials: A
authors.lastname: Welte
authors.affiliation: Health Economics and HIV and AIDS Research Division (HEARD), University of KwaZulu-Natal, KwaZulu-Natal, South Africa. Georgeg@ukzn.ac.za.
authors.forename: Gavin
authors.initials: G
authors.lastname: George
authors.affiliation: Health Economics and HIV and AIDS Research Division (HEARD), University of KwaZulu-Natal, KwaZulu-Natal, South Africa. Govenderk2@ukzn.ac.za.
authors.forename: Kaymarlin
authors.initials: K
authors.lastname: Govender
authors.affiliation: Centres for Disease Control and Prevention (CDC) Atlanta, Atlanta, USA. cot8@cdc.gov.
authors.forename: Carlos
authors.initials: C
authors.lastname: Toledo
authors.affiliation: Centres for Disease Control and Prevention (CDC), Pretoria, South Africa. chipetaz@sa.cdc.gov.
authors.forename: Zawadi
authors.initials: Z
authors.lastname: Chipeta
authors.affiliation: Centres for Disease Control and Prevention (CDC), Pretoria, South Africa. xxc4@cdc.gov.
authors.forename: Lycias
authors.initials: L
authors.lastname: Zembe
authors.affiliation: Centres for Disease Control and Prevention (CDC), Pretoria, South Africa. fev5@cdc.gov.
authors.forename: Mary T
authors.initials: MT
authors.lastname: Glenshaw
authors.affiliation: Global Clinical and Virology Laboratory, 11 Dan Pienaar Place, Amanzimtoti, South Africa. MLorna@GCVLABS.CO.ZA.
authors.forename: Lorna
authors.initials: L
authors.lastname: Madurai
authors.affiliation: Centres for Disease Control and Prevention (CDC), Pretoria, South Africa. che5@cdc.gov.
authors.forename: Varough M
authors.initials: VM
authors.lastname: Deyde
authors.affiliation: Centres for Disease Control and Prevention (CDC), Pretoria, South Africa. yek8@cdc.gov.
authors.forename: Alfred
authors.initials: A
authors.lastname: Bere
mesh_terms: D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D018791:CD4 Lymphocyte Count; D003430:Cross-Sectional Studies; D005191:Family Characteristics; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000821:virology; D015497:HIV-1; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods*; D015995:Prevalence; D012107:Research Design; D012111:Residence Characteristics; D012309:Risk-Taking; D013019:South Africa / Q000453:epidemiology; D019562:Viral Load; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents