tb and gender: some of the evidence stacie stender 14 january 2015
TRANSCRIPT
TB and gender: some of the evidence
Stacie Stender
14 January 2015
Outline
Jhpiego background Risk factors for TB Sex distribution Physiological hypotheses
and evidence Behavioural hypotheses
and evidence Gender related outcomes
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Reminder
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IJTLD 2008 Special Section
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The value of gender studies in TB control can be enhanced by 1.the ongoing collection of accurate disaggregated data 2.a balance in the collection and analysis of gender-based studies to capture not only the experiences of men and women but also the dynamism of the social relationships and interactions of other critical social, cultural and environmental determinants of health
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Jhpiego prevents the needless deaths
of women and their families.
Founded 1973 Affiliate of Johns Hopkins University Currently working in more than 50 countries Experience working in 154 countries More than 1500 employees worldwide
Jhpiego: Innovating to Save Lives
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Jhpiego’s Technical Expertise
Jhpiego works on: Family planning Maternal and newborn health Malaria Cervical cancer HIV/AIDS and TB Infection Prevention
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Jhpiego’s Approach
Jhpiego saves lives by: Building local human resource
capacity Working in partnerships with
government, NGOs, universities, professional associations and communities
Strengthening health care systems Developing evidence-based
innovations & sharing best practices
Risk factors for TB
HIV Malnutrition Diabetes Alcoholism Silicosis
Overcrowding Poverty Smoking Male sex
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Sex distribution
Varies by geographic location and year. Of 20 high-burden countries with data, median male:female ratio is 1.8:1; only Afghanistan reported a ratio of <1:1 (WHO, 2013)
A study in West Africa found male:female ratios of 2.03:1, with roughly even sex ratios among household contacts and community controls (Lienhardt et al, 2005)
A randomized household prevalence survey of 260,000 individuals in Bangladesh found male:female ratio of 3:1 (Salim et al., 2004)
Male bias dose not arise until puberty
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Global age-sex distribution of TB incidence in HIV-negative individuals in 2013
11Murray et al., 2014
Extrapulmonary TB (EPTB) is more prevalent in women
In the US, among 253,299 cases, compared with pulmonary TB, extra-pulmonary TB was associated with female sex (OR 1.7; 95% CI, 1.7-1.8). Being female was identified as independent risk factor for EPTB
Lin, 2009; Yang, 2004; Kingkaew, 2009; Lowieke, 2006
Tanzania Example
Male Female
Population 49% 51%
TB cases, all forms
59% 41%
Life expectancy
58 years 61 years
Notification rates: 1.8:1 ratio of male:female*
TB case mortality rate higher among males than females
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*Neither the prevalence survey nor active case finding efforts have diagnosed more females than expected from the notification data
Gender patterns of tuberculosis testing and disease in South Africa
14McLaren et al, 2015
HIV is the strongest risk factor for TB, yet despite higher HIV prevalence among women in sub-Saharan Africa, incidence of TB is higher in men
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…except among specific populations
DeLuca A et al, 2009
TB in women 15-24 years of age: in areas of high HIV prevalence, women have TB rates 1.5-2-fold higher than men
Physiology vs. behaviour
Physiology Biological differences
between sexes lead to variable susceptibility
Behaviour Primarily related to sex-
specific exposure to infection
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Nhamoyebonde and Leslie; JID 2014:209 (Suppl 3)
Physiological effects
Gonads may influence mycobacterial disease in mammals Male mice more susceptible; less severe disease
among castrated; females treated with testosterone increased susceptibility (Yamamoto et al., 1991)
8.1% of institutionalized mentally ill, medically castrated men died from TB compared with 20.6% of intact males and 15.8% of intact females (Hamilton et al., 1969)
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Physiological effects
7% TB death rate among women who had oophorectomy compared to country rate of 0.7% (Svanberg, 1981)
M. avium complex most common among post-menopausal women (Tsuyuguchi et al., 2001)
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Hypothesized physiological mechanisms
X-linked genetics Differences in immune response and effects of
sex hormones Differences in anatomy Differences in nutrition
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Gender-related behaviour
Differences in social roles, risk behaviors, and activities
Males may travel more frequently; have more social contacts; spend more time in settings that may be conducive to transmission; and work in settings associated with a higher risk for TB, such as mining (Narasimhan et al., 2013; Oni et al, 2012);
Time spent in household – household contact does not have gender bias (Grandjean et al., 2011)
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Gender-related behaviour
In many countries smoking is more frequent among men; a correlative analysis of cigarette smoking, sex, and TB suggests that smoking might explain up to one-third of the gender bias observed (Watkins and Plant, 2006)
Prevalence of alcohol consumption higher among men in low-income settings (Nhamoyebonde and Leslie, 2014)
Meta-analysis of 29 surveys conducted in 14 countries suggests access to healthcare not a confounding factor (Borgdorff et al., 2000)
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Gender related outcomes
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TB treatment outcomes stratified by gender in Ebonyi state, Nigeria, 2011-2012
Mean age of females lower than males (36.1 vs 40.2) Of the patients who had sputum smear done after 5
months of treatment, 1.5% of women still had a positive smear compared to 4.3% of men (P=0.02)
Similar treatment success rates Higher treatment failure rate among men - 2.2% vs
0.7% (P=0.01) HIV infection appeared to reverse the
‘immunoprotective effect’ of being female
24Oshi et al., 2014
Gender differences in delays in diagnosis and treatment of TB in Bangladesh
Both bivariate and multivariate analyses revealed longer delays for women than for men in total delay, total diagnostic delay and patients’ delay
Older women and young men were less likely to be diagnosed with TB through the existing TB control interventions, necessitating special drives to enhance case detection in these particular groups.
25Karim, et al., 2007
Overall
More males than females are diagnosed with TB Evidence that treatment success rates are better
for women than men in many settings (Nigeria, Mexico, India, UK, Malaysia) and equivalent in others (Brazil, Egypt, Syria)
Evidence of better treatment adherence among women than men
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Gender, locally-specific strategies are needed to improve TB control – limiting transmission is essential
The Three Delays Model of maternal mortality applies to TB & HIV morbidity and mortality
Delay in
1)decision to seek care
2)reaching care
3)receiving care
Thaddeus S, Maine D. Too far to walk: maternal mortality in context. Soc Sci Med 1994;38:1091-1110.
TB in Pregnancy
Prevalence of latent TB in pregnant women in HIV-endemic areas can be high.
In Tanzania, where antenatal prevalence of HIV was 5%, the prevalence of latent TB in pregnancy was 30% (Sheriff et al, 2010)
High rates of latent TB (49%) have been reported in antenatal clinics in South Africa (Nachega, 2003)
Country Mean Rate per 1000 pregnant women
South Africa 8400 10.3
Zimbabwe 2400 7.9
DR Congo 16200 7.2
Afghanistan 6100 7.2
Vietnam 900 0.8
Brazil 800 0.4
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Tuberculosis in pregnancy: an estimate of the global burden of disease among 22 HBC
Different epidemiology requires different approaches to TB identification and control: importance of pregnancy status
Sugarman et al., 2014
Maternal TB/HIV important risk factor for paediatric TB and mortality, Pune India
HIV-infected mothers have 10-fold increase in TB Maternal TB/HIV increased risk of postpartum mortality by
2.2 fold and probability of infant death by 3.4 fold
Maternal deathaIRR 2.2p=0.006
Infant deathaIRR = 3.4
p=0.02
Gupta A et al., 2007
715 HIV-infected pregnant women inPune, India
TB incidence 5/100 pt-yr(24 of 715 HIV+ women)
Programmatic challenges of TB symptom screening in MNH services
Kenya no routine collection of
data in the monthly summary sheets
TB data summary sheet does not specifically capture referrals from ANC
South Africa Provider bias of
screening women perceived to have a higher risk of TB*
Poor clinical staff moral and motivation*
High rates of extrapulmonary TB - harder to screen and diagnose*Gounder et al. JAIDS 2011; 57: e77-384
Malawi pilot results
Total ANC Attendees 5,474
Women screened for signs/symptoms of TB in ANC
3,920 (71.6%)
Women with signs/symptoms of TB 68 (1.7%)
Women with signs/symptoms of TB diagnosed with TB
4 (5.9%)
Women with signs/symptoms of TB diagnosed with HIV
8 (11.8%)
Number needed to screen to find one case 1369
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TB control requires implementation of locally-relevant, evidence-based interventions to address the special issues of both genders (including pregnancy among wwomen) and all ages to maximize effective access to the spectrum of essential services
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