Global Health for Engineers

Course Structure

An introduction to the professional field of Global Health, particularly focused on the areas of global health that engineers often contribute to – i.e. community environmental health. In a short course, we won’t have time to touch on things like health systems organization but there are many resources for additional learning.

We will be reading published peer reviewed studies of global health interventions – learning how to search for, read and analyze these kinds of studies is fundamental to being conversant in the field of global health. Many of these papers have engineers as co-authors.

This class is also an opportunity for group and 1:1 discussion. I am happy to meet with each of you individually to discuss career objectives and networking

Class will be heavy on case studies, with student-led facilitation

All readings posted in Canvas. Textbook is self-paced with online Canvas quizzes

See Canvas Syllabus for link to class schedule

Consortium of Universities for Global Health –

“An area for study, research, and practice that places a priority on improving health and achieving equity in health for all people worldwide.

Global health emphasizes transnational health issues, determinants, and solutions; involves many disciplines within and beyond the health sciences and promotes interdisciplinary collaboration; and is a synthesis of population-based prevention with individual-level clinical care.”

What is Global Health?

Overview, Key Concepts & Disciplines

Overview

Define the determinants, including social and economic, that impact health.

Highlight the differences in disease and life expectancy between high- and low-income countries.

Identify some of the dynamics in developing countries that impact health trends.

Key Concepts in Global Health

The determinants of health

The measurement of health status

The importance of culture to health

The global burden of disease

The key risk factors for various health problems

The organisation and function of health systems

Disciplines Involved in Global Health

Public Health

Public Policy

Medicine

Social Sciences

Behavioural Sciences

Law

Economics

History

Engineering

Biomedical Sciences

Environmental Sciences

Anthropology

Disease & Determinants of Health

Examples of disease that disproportionately impact developing countries

Malaria

Diarrhea

Pneumonia

HIV / Aids

99% of the children under the age of 5 who die every year lived in developing countries.

Determinants of Health

Genetics

Age

Gender

Lifestyle choices

Community influences

Income status

Geographical location

Urbanization

Climate Change

Governance

Culture

Environmental factors

Work conditions

Education

Access to health services

Source: Dahlgren G. and Whitehead M. 1991

Multi-sectoral Dimension of the Determinants of Health

Malnutrition –

• more susceptible to disease and less likely to recover

Cooking with wood and coal –

• lung diseases

Poor sanitation –

• more intestinal infections

Poor life circumstances –

• commercial sex work and STIs, HIV/AIDS

Advertising tobacco and alcohol –

• addiction and related diseases

Rapid growth in vehicular traffic often with untrained drivers on unsafe roads-

• road traffic accidents

Governance & Armed Conflict

Governance

Governance has a direct impact on socioeconomic status, health inequalities, and development

Allocation of Resources

Control of policy

Trade agreements

Regional politics

Abuse of power

Education

Image: Lvakurwa, 2009

Armed Conflict

The Results:

Disparities over resources and power

Broken relationship with neighboring countries

Lack of development

Inequality along race/gender lines

Resources diverted from health care to support conflict

Displacement

Health Implications:

Malnutrition

Diarrhea

Respiratory infections

AIDS

Extreme poverty

Negative long-term effects on health

Global Burden of Disease Walkthrough

http://vizhub.healthdata.org/gbd-compare/

http://vizhub.healthdata.org/sdg/

https://ourworldindata.org/burden-of-disease

Communicable Diseases

Defined as

• “any condition which is transmitted directly or indirectly to a person from an infected person or animal through the agency of an intermediate animal, host, or vector, or through the inanimate environment”.

Transmission is facilitated by the following (IOM)

• more frequent human contact due to
• Increase in the volume and means of transportation (affordable international air travel),
• globalization (increased trade and contact)
• Microbial adaptation and change
• Breakdown of public health capacity at various levels
• Change in human demographics and behavior
• Economic development and land use patterns

CD- Modes of transmission

Direct

• Blood-borne or sexual – HIV, Hepatitis B,C
• Inhalation – Tuberculosis, influenza, anthrax
• Food-borne – E.coli, Salmonella,
• Contaminated water- Cholera, rotavirus, Hepatitis A

Indirect

• Vector-borne- malaria, onchocerciasis, trypanosomiasis
• Formites

Zoonotic diseases – animal handling and feeding practices (Mad cow disease, Avian Influenza)

Impact of Communicable Diseases

Disease Burden

CDs account for about 30% of the global BoD and 60% of the BoD in Africa.

CDs typically affect LIC and MICs disproportionately.

• Account for 40% of the disease burden in low and middle income countries

Most communicable diseases are preventable or treatable.

Social Impact

Disruption of family and social networks

• Child-headed households, social exclusion

Widespread stigma and discrimination

• TB, HIV/AIDS, Leprosy
• Discrimination in employment, schools, migration policies

Orphans and vulnerable children

• Loss of primary care givers
• Susceptibility to exploitation and trafficking

Interventions such as quarantine measures may aggravate the social disruption

Economic Impact

At the macro level

• Reduction in revenue for the country (e.g. tourism)
• Drop in international travel to affected countries by 50-70%
• Malaria causes an average loss of 1.3% annual GDP in countries with intense transmission

At the household level

• Poorer households are disproportionately affected
• Substantial loss in productivity and income for the infirmed and caregiver
• Catastrophic costs of treating illness

Malaria

In 2022, there were an estimated 249 million malaria cases worldwide

• causes 30% of Low birth weight in newborns Globally.

In 2022, malaria killed an estimated 608,000 people. Malaria kills a child under 5 approximately every minute

40% of the world’s population is at risk of malaria. Most cases and deaths occur in SSA.

Malaria is the 9th leading cause of death in LICs and MICs

• 11% of childhood deaths worldwide attributable to malaria
• SSA children account for 82% of malaria deaths worldwide

Source: WHO World Malaria Report 2023

Malaria Control

Malaria control

• Early diagnosis and prompt treatment to cure patients and reduce parasite reservoir
• Vector control:
• Indoor residual spraying
• Long lasting insecticide treated bed nets
• Intermittent preventive treatment of pregnant women

Challenges in malaria control

• Widespread resistance to conventional anti-malaria drugs
• Malaria and HIV
• Health Systems Constraints
• Access to services
• Coverage of prevention interventions

HIV/AIDS

In 2023, 39.9 million people worldwide were living with HIV, of which 67% live in SSA

• 4.1 million people worldwide became newly infected
• 2.8 million people lost their lives to AIDS

New infections occur predominantly among the 15-24 age group.

First identified in the early 1980s. Has affected over 85 million people since the start of the epidemic.

Source: UNAIDS Global AIDS Update 2023

HIV Co-infections

Impact of TB on HIV

• TB considerably shortens the survival of people with HIV/AIDS.
• TB kills up to half of all AIDS patients worldwide.
• TB bacteria accelerate the progress of AIDS infection in the patient

HIV and Malaria

• Diseases of poverty
• HIV infected adults are at risk of developing severe malaria
• Acute malaria episodes temporarily increase HIV viral load
• Adults with low CD4 count more susceptible to treatment failure

Engineers, Doctors, Epidemiologists, Public Policy Makers and People

Epidemiology Purposes in Public Health Practice

Discover the agent, host, and environmental factors that affect health

Determine the relative importance of causes of illness, disability, and death

Identify those segments of the population that have the greatest risk from specific causes of ill health

Evaluate the effectiveness of health programs and services in improving population health

Epidemiology Key Terms

epidemic or outbreak: disease occurrence among a population that is in excess of what is expected in a given time and place.

cluster: group of cases in a specific time and place that might be more than expected.

endemic: disease or condition present among a population at all times.

pandemic: a disease or condition that spreads across regions.

rate: number of cases occurring during a specific period; always dependent on the size of the population during that period.

Measurement of Health Status

Cause of death

• Obtained from death certification but limited because of incomplete coverage

Life expectancy at birth

• The average number of years a new-borns baby could expect to live if current trends in mortality were to continue for the rest of the new-born's life

Maternal mortality rate

• The number of women who die as a result of childbirth and pregnancy related complications per 100,000 live births in a given year

Infant mortality rate

• The number of deaths in infants under 1 year per 1,000 live births for a given year

Neonatal mortality rate

• The number of deaths among infants under 28 days in a given year per 1,000 live births in that year

Child mortality rate

• The probability that a new-born will die before reaching the age of five years, expressed as a number per 1,000 live births

Scenario: Unexplained Pneumonia

July 21–24

July 26–Aug 1

August 2

(Morning)

August 2

(Evening)

American Legion Convention,

Philadelphia, Pennsylvania

18 deaths reported among conventioneers

Health care provider at a veterans’ hospital in Philadelphia calls CDC to report casesof severe respiratory illness among attendees of the American Legion Convention

71 additional cases reported

Fraser DW, Tsai, T, Orenstein W, et al. Legionnaires’ disease: description of an epidemic of pneumonia. New Engl J Med 1977;297:1189–97.

Epidemiology Study Types

Epidemiology study

types

Experimental

Observational

Descriptive

Analytic

Confounding

Occurs when an extrinsic factor is associated with a disease outcome and, independent of that association, is also associated with the exposure

Exposure Outcome

Confounder

Measuring the association between exposure and outcome variables

The appropriate measure of association to use depends on the nature of the data

When exposure and outcome variables are dichotomous (two-level nominal data)

• Odds ratio – use with case-control study (observational)
• Risk ratio – use with cohort study (controlled)
• Rate ratio – use with cohort study (controlled)

“Risk” refers to the probability of occurrence of an event or outcome.

“Odds” refers to the probability of occurrence of an event/probability of the event not occurring.

Expressing RRs as Percentages

We can also express these RRs as percent change

• RR > 1 % Increase Change = (RR – 1) × 100
• RR < 1 % Decrease Change = (1 – RR) × 100

When does the odds ratio approximate the risk ratio?

For health-related states or events that are rare (i.e., affecting less than 10% of the population),a + b can be approximated by b, and c + d can be approximated by d

Develop strategies for particular groups to engage in change toward health

Provide a support system to initiate change and sustain positive behaviors

Goal of intervention

Approaches to Interventions

Personal responsibility and action

Utilitarian Approaches – “Greatest good for the greatest number”

• Including non Health Systems Interventions.

Regulations and Laws

Partnerships and Collaboration

Enlightened Self Interest

Education

Develop favorable attitudes towards the behavior

Training (i.e. Community health workers)

Participatory engagement

Provide sustainable access

Utilizing underlying skills of the local people

Supportive Environment

• Utilizing families, local organizations, community leaders, policy makers

How?

Why Do People NOT Change Behavior?

Do they understand the message?

Do they see themselves as vulnerable?

Do they trust the ones who present the message?

Do they think the benefits of change are worth the long-term benefits?

Is it too costly?

Does change contradict with their religious beliefs?

Perceived susceptibility-risk of acquiring the disease

Perceived severity-perception on the risk of acquiring the disease

Perceived benefits-is it worth the change?

Perceived barriers-obstacles to achieving health change

Cue to action-what will trigger this change?

Self-efficacy-how confident is the person to successfully perform a behavioral change?

Health Belief Model

Programme Overview

The Tubeho Neza ("Live Well") programme was one of the world's first carbon-credit-financed health interventions, distributing water filters and improved cookstoves across Western Province, Rwanda.

• First-ever UN CDM and Gold Standard programmes earning carbon credits for water treatment
• Carbon credit revenue funded distribution, training, and ongoing monitoring
• Implemented through Rwanda's existing Community-Based Environmental Health Promotion Programme (CBEHPP)
• Community health workers (CHWs) served as the primary delivery and behavior change channel
• Cluster-randomized controlled trial design to rigorously evaluate health impacts

Evan A. Thomas, PhD, PE, MPH — Director, Professor, University of Colorado Boulder

Field Context

Regional Context — DR Congo

Programme Implementation

Monitoring & Data Collection

Key Results

• 73% reduction in indoor air pollution among outdoor cooks
• 38% reduction in cryptosporidium exposure seroconversion
• 97.5% reduction in fecal contamination of drinking water (RCT finding)
• 48% reduction in cooking area air pollution
• 25% reduction in acute respiratory infections in children under 5
• Over 90% adoption rate maintained through CHW-delivered behavior change

Sources: Thomas et al., Lancet Planetary Health (2018); Kirby et al., PLOS ONE (2014)

Technology & Digital Monitoring

Water Filters

• LifeStraw Family 2.0 household water filters
• Significant microbiological effectiveness reducing E. coli contamination
• Free distribution with carbon waiver for credit generation

Remote Sensing Innovation

• Electronic sensors remotely transmitting usage data
• Sensor-reported use was substantially lower than self-reported use
• Demonstrated critical value of objective digital monitoring
• Published in ACS Environmental Science & Technology

Carbon Credit Model

• Pay-for-performance model funded by voluntary carbon credits
• Health, livelihood, and environmental benefits substantially outweighed costs
• Fuel savings and averted healthcare costs = largest economic gains

Scale & Lessons Learned

Published Research (13 Papers)