HIV and HSV-2 risk among young women in age-disparate partnerships: evidence from - PowerPoint Presentation

Slide1

HIV and HSV-2 risk among young women in age-disparate partnerships: evidence from

KwaZulu-Natal, South Africa

Brendan Maughan-BrownSouthern Africa Labour and Development Research Unit (SALDRU), University of Cape TownGavin George, Sean BeckettHealth Economics and HIV and AIDS Research Division (HEARD), University of KwaZulu-NatalMeredith EvansDepartment of Anthropology, York University, Toronto, CanadaCherie Cawood, David KhanyileEpicentre AIDS Risk Management, South AfricaLara Lewis, Ayesha BM KharsanyCentre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-NatalParis- 25 July, 2017Slide2

Background

HIV incidence is persistently high among young women in sub-Saharan Africa

.Evidence remains mixed whether age-disparate partnerships increase HIV-risk for young women.Uncertainty regarding value of risk reduction interventionsCompounding factors suggest increased HIV risk:Age-disparate male partners are more likely to be HIV-positive; Riskier sexual behaviours reported within age-disparate partnerships.Could patterns of ART uptake among men mitigate HIV-infection risk within age-disparate partnerships?HIV testing and ART uptake positively associated with age; Age-disparate HIV-positive partners more likely to be on ART.Slide3

Study

aimsPrimary

To assess the association between age-disparate partnerships and HIV status among 15-24 year old women in a high HIV prevalence region of South Africa.To examine whether the proportion of young women’s partners who are HIV-positive with a viral load ≥1000 copies/ml (i.e. pose a transmission risk) differs between age-disparate and age-similar partnerships.SecondaryTo assess the association between age-disparate partnerships and HSV-2 as HSV-2 is associated with increased HIV-infection risk.Slide4

Methods:

DataHIV Incidence Provincial Surveillance System (HIPSS)

1st baseline household survey (June 2014-2015)KwaZulu-Natal, South Africa2 neighbouring regions: 1 urban, 1 ruralRandom sampling ofEnumeration AreasHouseholdsOne individual (15-49) per householdBaseline sample: N = 9812 individuals Venous blood samples for HIV and HSV-2 testsFace-to-face questionnaire1st ever & 3 most recent sexual partnersStart dates of relationshipsDate & result of last HIV testSlide5

Methods:

HIV & HSV-2 among young womenDependent variablesHIV positive (ref: HIV negative)

HSV-2 positive (ref: HSV-2 negative)Age-disparate variablesUNAIDS definition: male partner ≥ 5 years olderThree binary measures of exposure to age-disparate relationship:most recent partnership is/was age-disparateat least 1 of a woman’s 3 most recent partnerships was age-disparateat least 1 of a woman’s 3 most recent partnerships or her first-ever relationship was age-disparateNB: partnerships (n=142) started after an HIV-positive diagnosis excludedunrelated to HIV infectionSlide6

Methods:

HIV & HSV-2 among young womenAnalysis

15-24 year old women with data on a sexual partner (N=1459)Multiple logistic regressionSeparate models for three age-disparate measuresControl measures: age, education, hh SES, #sexual partners, past HIV-testing, HIV knowledgeWeighted data & adjusted standard errors (clustering at the enumeration area level)Young women15-24 (n=1459)Slide7

Methods

: HIV prevalence and viral load among young women's

partnersDataAll ongoing partnerships men reported with a woman 15 to 24 years old (N=1229)Assumption: represent all partnerships involving 15 to 24 year old women

Young women

Men (15-49 years old) in partnership with young women aged 15-24

Dependent variables:

HIV positive

HIV+ & viral load ≥1000 copies/ml

Independent variables - 3 categories of age-disparate partners:

Men ≥5 years older

Men 5-9 years older

Men ≥10 years older (intergenerational)Slide8

Methods

: HIV prevalence and viral load among young women's

partnersAnalysisMultiple logistic regression models association between partnership type and HIV status and viral load of male partnersControl var: female partner ageWeighted data & adjusted standard errors (clustering at the enumeration area level)

Young women

Men (15-49 years old) in partnership with young women aged 15-24Slide9

Results

: age-disparate partnerships

  % [95%CI]Partnerships reported by young women Age-disparate (5+ year gap)  Last partner 32% [28-35]

Any of last 3 partners

36

% [32-40]

1

st

or

any of last 3 partners

42

% [37-46]

Partnerships (on-going) reported by men

5

+ age

gap

26

% [22-30]

5-9

year

gap

19

% [16-23]

10

+ year

gap

7

% [4-9]Slide10

Results:

HIV & HSV-2 among young women

 HIV+HIV+ OR [95%CI]aOR

[95%CI]

Last partner

Age-similar

ref

ref

Age-disparate

1.62***[1.26-2.09

]

1.51*** [1.15-1.99]

Last 3 partners

Age-similar

ref

ref

Age-disparate

1.75*** [

1.35-2.28]

1.58*** [1.20-2.09]

1

st

or last 3 partners

Age-similar

ref

ref

Age-disparate

1.92*** [1.41-2.61]

1.56** [1.08-2.26]

HSV-2+

aOR

[95%CI]

ref

1.65*** [1.27-2.15]

ref

1.62*** [1.23-2.14]

ref

1.80*** [1.34-2.42]

***p<0.01;

**

p<0.05

25%

36%

25%

37%

22%

35%Slide11

Results:

HIV prevalence and viral load among young women's partners

HIV+HIV+ with viral load≥1000 copies/ml aOR(95%CI)

aOR

(95%CI)

Partnership age-gap

(ref:

≤4 years)

5-9 years

2.27***

2.01**

(1.34 - 3.84)

(1.17 - 3.46)

10+ years

5.50***

2.17**

(2.62 - 11.52)

(1.05 - 4.51)

aOR

: 2.92*** (95%CI: 1.82 - 4.69)

aOR

: 2.05*** (95%CI: 1.29

–

3.26)

11%

27%

9%

17%

***p<0.01;

**

p<0.05Slide12

Conclusions

Age-disparate partnerships associated with increased HIV risk

Consistent with a phylogenetic transmission network analysis conducted using a sub-sample of participants from the HIPSS studyConsistent with recent longitudinal dataInterventions to reduce HIV infection risks associated with age-disparate partnerships may help to prevent new infections among young womenResults indicate biological plausibility for the positive associationAge-disparate partners more likely to pose an HIV-infection riskHIV-prevention among young women = early diagnosis and treatment of HIV-positive men in age-disparate partnershipsART uptake patterns may mitigate the additional risk posed by intergenerational partnerships. The distinction between different types of age-disparate partnerships may be less relevant when considering biological risk. Slide13

Acknowledgments

HIPSS sponsorship and funding Statement

HIPSS was funded by the US President’s Emergency Plan for AIDS Relief (PEPFAR) through the US Centers for Disease Control and Prevention (CDC) under terms of the co-operative agreement 3U2GGH000372-02 W1

HIPSS Protocol implementation and analysis

Ayesha BM Kharsany, Principal Investigator

Cherie

Cawoood

, Project Director

David

Khanyile

, Field Project Manager

Anneke Grobler, Study Statistician

Lara Lewis, Study Statistician

Investigators

Centre for the Programme of AIDS Research in South Africa (

CAPRISA)

Epicentre AIDS Risk Management

Health Economics and HIV/AIDSs Research Division (HEARD)

Southern Africa Labour and Development Research Unit (SALDRU), University of Cape Town

HIPSS Collaborating Partners

uMgungundlovu District office DOH

HAST Unit, KZN Department of Health

KZN Department of Health

National Institute for Communicable Diseases, National Health Laboratory Service (NICD/NHLS)

To all the households and individual study participants, traditional and municipal leadership, HIPSS field and office staff, all laboratory staff and PHC clinic staff in the district