Infectious Disease in Africa: lessons learned and their application Michael Welsh, Ph.D.

Topics l Population structure and public health challenges l Infectious disease l HIV Epidemiology l Lessons learned in HIV prevention

Population of Sub-Saharan Africa by Age and Sex: 2000 to 2005 Source: U.S. Bureau of Census. Male Female Age group < 15 represents 44% of the total population

Fertility Decline in Selected World Regions, Early 1960s to 2005 Children per woman* * The average total number of children a woman will have given current birth rates. Source: US Bureau of the Census, International Data Base, September 23, 2002.

Use and Total Unmet Need* Women Source: Demographic and Health Surveys. *All women 15-49, modern methods. **Currently married women 15-49, modern methods.

Infant Mortality by Birth Interval On average, infants born after short birth intervals are twice as likely to die as those born after intervals of two or more years. Source: Country DHS Reports. * Figures here are only for a 2 year birth interval instead of a 2-3 year interval.

Traditional Epidemiological Framework Agent Host Environment Disease Source: Center for Health and the Global Environment, Harvard Medical School

Leading causes of death in Africa, 2000 Source: The World Health Report 2001, WHO HIV/AIDSMalariaPerinatal conditions Tuber culosis Cerebro vascular disease Diarrhoeal disease Lower respiratory infections Measles Ischaemic Heart disease Maternal conditions % of Total

Infectious disease deaths as proportion of all deaths by region, 2001

Question l Why do you think that Africa has such a serious problem with ID?

Factors that contribute to infectious disease in Africa l Poverty: root cause - poor most vulnerable l Demographics: children and women vulnerable l Poor nutrition/food supply: weakens immunity l Access to water ? l Urbanization/housing l Environmental factors l Public health systems l Risk behaviors

Per capita gross national income by region (US $) Source: Sachs J. et al., Ending Africa’s Poverty Trap, Brookings Institution, 2004

Health Expenditures per Capita

Physicians per 100,000 people: Source: Human Development Report 2003 New York: Oxford University Press, 2003

Measles coverage at 1 year World Development Indicators, World Bank, 2002

Nutritional Deficits l Annual population increase 2.5 % l Population doubles in approximately 20 years l FAO estimate that 50 % already go “hungry” l Per capita food production has declined since the 70s l Little to no food surplus

Access to Improved Water Sources Source: USAID (2002)

AIDS Mortality Cumulative mortality in US thru Dec 2001 Mortality in sub-Saharan Africa in a single year, 2002

15-35% 3-7% 1-5% 0-0.1% HETEROGENEITY OF HIV IN AFRICA

HETEROGENEITY OF HIV IN AFRICA A TALE OF THREE EPIDEMICS Manzini, Swaziland Kampala, Uganda Dakar, Senegal

PREVENTION LESSONS FROM GENERALIZED EPIDEMICS  Stigma  Concurrent sexual partnerships  Inter-generational sex  Sexual coercion – gender norms  Vulnerability of couples Funding should track with transmission  Male circumcision

HOUSEHOLD HIV PREVALENCE IN FRANCISTOWN, BOTSWANA MaleFemale

PERCENTAGE WHO KNOW RELATIVE/FRIEND WHO HAS DIED OF AIDS

SEXUAL NETWORKING IN LIKOMA,MALAWI Source: Kohler H and Helleringer S. The Structure of Sexual Networks and the Spread of HIV in Sub-Saharan Africa: Evidence from Likoma Island (Malawi). PARC Working Paper Series: WPS  Fifth of population in mutually exclusive relationships  Two-thirds linked by single network over last three years  Networks not anchored by “high frequency transmitters”  Decentralized, complex, robust sexual chains

PROPORTION OF YEAR OLDS IN SOUTH AFRICA WITH SEX PARTNERS 5 OR MORE YEARS OLDER MaleFemale HIV PREVALENCE AMONG YEAR OLDS IN SOUTH AFRICA WITH SEX PARTNERS 5 OR MORE YEARS OLDER Sex partner 5 or more years olderSex partner less than 5 years older

SEXUAL PARTNERSHIPS IN SWAZILAND 0% 10% 20% 30% 40% 50% 60% GuardsDriversSoldiersPoliceSeasonal workers SEXUAL PARTNERSHIPS IN LESOTHO 0% 20% 40% 60% 80% SoldiersMinersDrivers Casual sex Commercial sex

SEXUAL COERCION IN RAKAI, UGANDA HIV INCIDENCE IN RAKAI, UGANDA

HIV PREVALENCE AND TRANSMISSION SOURCES IN ZAMBIA, 2005 Infections from sex work, clients, soldiers, truckers Infections from general population 93% 7% 50% 14%

HIV PREVALENCE AND TRANSMISSION SOURCES IN ACCRA, GHANA, 2005 Adult male infections from sex work Adult male infections from general population 2% 78% 24% 76%

HIV PREVALENCE, TRANSMISSION SOURCES AND FUNDING IN ACCRA, GHANA 78% 2.2% 76% 24%.08% 99.2% 0% 20% 40% 60% 80% 100% Sex workersGeneral population HIV prevalenceTransmission sourcesFunding

BEHAVIORAL AND HIV TRENDS IN KENYA Males reporting multiple partners HIV prevalence

Percent reporting multiple partners BEHAVIORAL AND HIV TRENDS IN UGANDA Men with one or more casual partners in last year Women with one or more casual partners in last year Men with three or more casual partners in last year Adult HIV prevalence HIV prevalence

Circumcision and HIV Prevalence

Impact on HIV incidence: Evidence from observational studies and RCTs Effect size Study Effect size (95% CI) Overall 0.42 ( 0.34, 0.52) High-risk groups 0.29 ( 0.20, 0.42) General Population 0.56 ( 0.44, 0.71) South Africa 0.40 ( 0.24, 0.67) Kenya 0.41 ( 0.24, 0.70) Uganda 0.49 ( 0.28, 0.86)

Evidence from RCTs SitePopulationEffect Orange Farm, SA % Rakai, Uganda15 – 4948 % Kisumu, Kenya18 – 2453 %

FP Complements Other Programs to Reduce Infant Infections/Deaths Source: USAID, Benefits of integrating family planning and nevirapine programs – annual projection of infections and deaths averted

HIV – AIDS Prevalence 25.4 million Incidence 3.1 million Mortality 2.3 million HAS HIV INCIDENCE PEAKED IN AFRICA? HIV prevalence has fallen in several African countries – as the balance between HIV incidence, HIV prevalence and mortality shifts

Interventions that work l Male circumcision l ARVs! l Targeted interventions with BCC and condom promotion l ABCs l VCT l STI Rx and Dx l PMTCT and FP

Important New Initiatives l PEPFAR l Gates Foundation (Buffett) l Global Fund for AIDS Malaria and TB

Summary l Poor health effects women and children disproportionately l FP is a key intervention l ID extracts a huge burden on Africa and frustrates development l Generalized and concentrated HIV epidemics demand customized responses l AIDS taking a toll; new knowledge and large investments fuels hope