L5 Child Health

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Global health

Reducing child mortality

Activity 3: Research Article

! Learn how to read researcharticles critically

! Title: Comparison of home-based therapy with ready-to-use therapeutic food with standard therapy in thetreatment of malnourished Malawianchildren: a controlled, clinical effectiveness trial .! American Journal of Clinical Nutrition,

2005

! Posted on my website as “A ctivity 3article 2005”

! Activity 3: read the article and answer the questions

“Big 4” infectious diseases thatkill children <5 yrs old worldwide

! Diarrhea! Kills 2 million infants and children each

year, usually from dehydration

! Respiratory infections! Pneumonia kills ~2 million children each

year

! Malaria

! AIDS

MDG 4:Reduce child mortality

! In 1990 12.6 million childrendied from preventablecauses

! This number has been cut to9 million

! Interventions:

! Vaccination campaigns(measles, etc)

! Expanding basic healthservices

Status report: MDG 4

! GOAL 4: Reduce child mortality

! Good Average Poor

!

Drop in the number of children dying of preventable causes

! BUT child mortality has increased in sub-Saharan Africa

! AIDS and malaria

1. Good nutrition

2. Good hygiene

3. Immunizations

The 3 most important thingsto protect children’s health:



What happens when a childdoesn’t get enough food?

! When the mom is malnourished, her fetus doesn’tgrow normally

! Low birth weight

! If the child is chronically underfed, s/he doesn’t grownormally

! Stunting

! A transient lack of food leads to extreme thinness butrelatively normal height for age

! Wasting

! Micronutrient deficiencies

! Iron, iodine, vitamin A

Maternal malnutritionincreases infant mortality

! Every year, >20 million low-birth weight babies are bornin developing countries

Increased risk dying ininfancy

! Those who survive oftensuffer lifelong physical andmental disabilities

I n f a n t m o r t a l i t y

( d e a t h s / 1 0 0 0 b i r t h s )

I n d u

s t r i a

l i z e d

D e v

e l o p i n

g

Undernourished children

! Stunted growth, wasting

! Poor motor development

! Impaired mentaldevelopment

! Reduced learningcapacity

! Behavioral problems

! Decreased resistance toinfection

! Diarrhea and respiratory

infections (pneumonia)

Vicious cycle of malnutritionand illness

Poor nutrition Infection

! Weakened immunesystem

! Increasedsusceptibility toinfection

! Loss of appetite

! Vomiting

! Diarrhea

! Weight loss

Diarrhea and dehydration

! Diarrhea is common in developingcountries

! 60-70% of child deaths due to diarrhea

! Often caused by contact with food/water contaminated with feces

! Leads to dehydration

! Death can occur within 24 hr

What causes diarrhea?

! Bacteria

! Found in contaminated water

! cause typhoid, cholera, etc.

! Found in contaminated milk and dairy

products, salads and poultry (Shigellabacteria)

! Ameba - cause amebic dysentery

! Found in food or water contaminated byfeces

! Rotavirus family of viruses

! Commonly infect children

An ameba



Cholera

! Caused by a toxin secreted into theintestine by the bacterium Vibrio

cholerae

! Bacteria is transmitted bycontaminated water or food

! Sx: Massive watery diarrhea

! Loaded with bacteria

! Spreads the infection

! One of the most rapidly fatal illnessesknown

! Dehydration

! Rx: oral rehydration therapy Cholera hospital in Dhaka

Simple Rx:Oral Rehydration Therapy

! One of greatest public healthbreakthroughs of 20th century

! ORT prevents 1 million deaths per year

! Replace the fluid and salt lost throughdiarrhea

! Rehydration solution contains water,salt and sugar

! Add sugar - enhances transport of salts across intestinal wall

! Caveat: best to use clean (boiled) water so don’t re-infect the child

Preventing Diarrhea

! Clean water

! Good hygiene

! Wash your hands! After pooping, diaper changes, before preparing meals andfeeding kids

Waterborne diseases

! Safe drinking water andsanitation are key to publichealth, yet! 1/3 of world’s population lacks

modern sanitation

! 1/6 of population lacks access tosafe drinking water

! Contaminated water ! Leading cause of disease and

death

! Single largest killer of infants

! Principal cause of illness in adults

Preventing waterbornediseases

! Build basic infrastructure: Water treatment and sanitation systems

! Treat sewage before it enters the

waterways

! Water purification

! Sterilize all water used for drinking,washing, or cooking by boiling or chlorination

Not a small problem …

! Over 2 billion people (1/3 of the world’spopulation) still lack modern sanitationand hygiene needed to protect their

environment from human fecalcontamination



Complex challenges for developing nations

! Contaminated water

! Uncollected garbage

! Untreated sewage

! Other disease vectors

! rodents (plague), mosquitoes (malaria, denguefever), flies, cockroaches, …

! Parasites: tapeworms, hookworms, etc.

! Contaminated food due to no refrigeration

Respiratory infections/pneumonia

! Indoor air pollution is a major contributing factor

! Half the world’s people use dung, wood,or coal for cooking and heating

! Poor ventilation of smoke (no chimney)

! Pneumonia

! an infectious disease caused by varietyof pathogens: bacteria, viruses,parasites or fungi

! Causes severe inflammation of lungs,difficulty in breathing

Two billion people use openfires as their primarycooking method.

Infectious disease: Malaria

! Malaria kills more than 3000children under the age of 5 eachyear

! The majority of the cases occur in Africa, where poverty is thebiggest problem facing thisepidemic

! Prevention! mosquito nets and mosquito repellant

! mosquito control (pesticides)

! No vaccine is available–yet

Infectious disease: Measles

! The world’s most contagious disease! Caused by a virus

! Young, malnourished children espvulnerable

! In developing nations, a child has a5-15% chance of dying from measles

! Many survivors suffer seriouscomplications! Blindness, loss of hearing, nerve damage

Preventing Measles

! Vaccination! Vaccine costs 26 cents per dose – but has yet to

reach many of the world’s poorest countries.

! Vaccine has not reached everyone in Africa, South Asia

! Vaccination: if >90% coverage, the populationwill achieve “herd immunity”

! Immunization levels high enough so that minoritynot immunized will still be protected.

Importance of immunizations

! Measles vaccination program in Latin American and Caribbean

! Strategy of “catch up, keep up and follow up”! “Catch up” campaign to achieve 90% vaccination

coverage! Maintenance to “keep up” to 80% coverage

! Regular “follow up” campaigns every 3-4 yrs

! Dramatic drop in measles cases! 250,000 in 1990

! 537 in 2001



What is a vaccine?

! Purpose: get the immune systemready to fight without exposing

anyone to active germs

! What’s in that syringe?

! Dead or weakened viruses

! Inactivated toxins

! Part of a virus

! Boost the immune system sothat it produces antibodies to thepathogen

Strategies for improvingchild survival

Interventions that improvehealth and nutrition

! Promoting breast feeding

! Educating moms about feeding at weaning

! Micronutrient supplements

! Vitamin A and zinc supplements for kids

! Could reduce deaths by about 10%

! Calcium, iron & folate supplements during pregnancy

! prevent 1/4 of all maternal deaths

! Reduce the burden of disease

! Promote hand washing

! Reduce malaria (bed nets)

Breastfeeding–Global recommendations

! Educate new moms aboutthe benefits of breast milk

! Encourage mothers tobreastfeed exclusively for first 6 months

! Continue breastfeedingwith complementary fooduntil the child is at least 2

Breast feeding - advantages

! Optimal nutrients for healthy growth

! Contains antibodies thatprotect against disease

! Sanitary

! Always ready

! Inexpensive

! May delay subsequentpregnancies

Breastfeeding Setbacks

! The number of infants exclusively breastfedto 4 months has dropped to ~50%

! Aggressive promotion of infant formula to

new mothers! More women working outside the home



What if the mother is HIV-positive?

! A complicated decision

! The HIV virus is transmitted through breast milk

! Need to educate HIV-positive moms

! Shortened duration of breast feeding is an option – esp. in areas that lack clean water

! Study: Infants of HIV+ moms breast fed for the first 3-mo have same risk of contacting HIV as infants fedformula

Challenges–

! Implementing successfulprograms

! Promoting exclusive breast feedingfor the 1st 6 months

! Micronutrient supplementation

! Reaching those in need

! Women

! Young children (esp under 2 yrs)

! The poor

Deadliest diseases for adults

! HIV/AIDS

! TB

! Malaria

Top 6 “killer” infectiousdiseases worldwide

Disease Estimated # of deaths

1. Respiratory infections 3.9 mil lion

2. HIV/AIDS 2.9 million

3. Diarrhea 2.0 million

4. Tuberculosis 1.6 million

5. Malaria 1.1 million

6. Measles 0.7 million

WHO 2002

Tuberculosis (TB)

! Caused by the bacterium Mtb

! A contagious, airborne disease! Transmitted thru coughing,

sneezing, talking

! A person with active TB infects 10-20 others, often family members andcaretakers

! TB usually attacks the lungs anddestroys lung tissue! Sx: severe cough, chest pain,

coughing up blood

Infection with Mtb

! Latent! The immune system sequesters the bacteria and

prevents them from multiplying

! May persist for years without making its host ill

! 90% of people infected with Mtb never developactive TB disease

! Active TB! Develops in people with weak immune systems

! Bacteria multiply rapidly and attack the organs,esp the lungs



TB

! 98% of new infections occur in the developingworld

! Rising number of people in industrialized

nations are contracting TB

! their immune systems are compromised by AIDS,immunosuppressive drugs, substance abuse

! Global transmission by jet travel

! Leading cause of death among people withHIV/AIDS

Treating TB

! Difficult, expensive,requires long courses of multiple antibiotics

! Drug-sensitive TB isusually cured with acombination of first-linedrugs taken for 6 to 9months.

! These drugs weredeveloped more than40 years ago.

Antibiotic resistance is agrowing problem

! Many patients stop taking meds when they begin to feel well

! Inconsistent use of antibiotics give the bacteria time to evolveinto a drug-resistant form

Multidrug resistant TB (MDR-TB)

! MDR TB occurs when the Mtbstrain is resistant to the mostpowerful first-line drugs.

! To cure MDR TB, a combination of second-line drugs is used

! These drugs have more sideeffects, the treatment lasts muchlonger, and the cost may be up to100 times more than first-linetherapy

Challenges in TB treatment

! 20% of TB cases are resistant to standard treatments! Multidrug-resistant TB (MDR-TB)

! Extensively drug-resistant TB (XDR-TB)

! Desperate need for better drugs and vaccines!

Drugs that are easier to administer and cheaper ! Vaccine to prevent TB infection in the 1st place

! Mtb genome was sequenced in 1998! new insights into how the bacterium infects humans

! Gates Foundation: $$ to develop new drugs and vaccines

Malaria

! Caused by a tiny parasiticprotozoa, Plasmodium

! Vector: female Anopheles

mosquito! Parasites transmitted from

one human to another by thebite of this mosquito



Malaria–populations that face the greatest risk

! Endemic to tropicalareas in Africa, Asiaand South America

! Each year 250-500million people areinfected

! Vast majority of victims are childrenunder 5

World Malaria report 2010

! Deaths from malaria dropped 21% over past9 yrs

! Vast majority of victims: children under 5

! strategies to fight malaria! Bed nets in sub-Saharan Africa

! Spray houses with insecticide

! Rapid diagnostic tests

! Combination therapy

Malaria–the parasite has a complex life cycle

! Starts in the salivary glands of mosquitoes

! Moves to the humanbloodstream

! Migrates to the liver where itreproduces, forming thousandsof merozoites.

! These invade RBCs andmultiply, causing the cells torupture and infect more RBCs.

! Finally moves back into thebody of a new mosquito

Malaria symptoms

! Sx: severe fever and flu-likeillness, chills, anemia

! Sx caused by! the massive release of

merozoites into thebloodstream

! Anemia results from thedestruction of RBCs

! Jaundice (yellow-colored skinand eyes) caused by largeamounts of hemoglobinreleased into the blood after RBCs rupture

RBC bursting after

malaria infection

Malaria–transmission

! The parasite enters thehuman body in one of three ways

!

The bite of infected Anopheles mosquitoes

! Congenitally (from amother to her fetus)

! Transfusions withinfected blood

Malaria - interventions

! Insecticides to kill mosquitoes! DDT used indoors to kill mosquitoes w/o harming environment

! Mosquito nets for beds ( Anopheles is a night feeder),insect repellants

! Anti-malarial drugs! must be taken continuously to reduce infection

! Too expensive for people living in endemic areas

! Plasmodium parasite is becoming resistant to older medications

! No vaccine for malaria - yet



Malaria vaccine 3:22http://www.pbs.org/newshour/video/module_byid.html?s=news01pb88

Why isn’t there a vaccine for malaria?

! Developing a malaria vaccine is one of the mostimportant research projects in public health, but ...

! The malaria parasite is a complex organism with acomplicated life cycle.! It is constantly changing – so developing a vaccine is

difficult.

! Scientists don’t understand the immune responsesthat protect humans against malaria.

Promising new vaccinestrategies

! A stronger traditional vaccine

! Chemicals added to boost the immune response

! In late stage clinical trials, but only 50% e ffective

! A vaccine from weakened parasites

! Irradiate parasites in the mosquito’s gut, then inject pieces of weakened parasite into humans to trigger immune response

! Develop a vaccine for mosquitoes

! To break the cycle of transmission

Socio-economic effects

! Malaria is associated with poverty! but is also a cause of poverty

! Malaria hinders economic development! impact includes costs of health care

! working days lost due to sickness

! days lost in education

! decreased productivity

! PBS - Malaria in Tanzania 3:55! http://www.pbs.org/newshour/video/search_results.html?q=malaria&submit=Search

Genetic disorders:

Sickle-cell Anemia

! A recessive genetic disorder

! Caused by a mutated gene thatproduces a defective version of hemoglobin

! The hemoglobin sticks together and produces a stiff red bloodcell with a sickle-shape

! Sickled RBCs are destroyedrapidly, leading to anemia

Sickle cell trait and malaria

! People (and particularlychildren) infected withmalaria parasite are more

likely to survive the acuteillness if they have sickle celltrait.

! The sickling of the cells haltsinfestation of the malariaplasmodium

Neglected Tropical Diseases




! About 1 billion peopleare affected by one or more neglected tropicaldiseases (NTDs)

! Diseases of poverty! These diseases are

named "neglected"because they persist inthe poorest and the mostmarginalized populations.


! Most are parasitic or bacterialinfections! Parasitic worms that live in the intestine

! Rob children of nutrients, stunting their growth

! Don’t often kill, but they debilitate bycausing severe anemia,malnutrition, delays in cognitivedevelopment

! They help perpetuate poverty! Children have trouble learning in school

! Adults workers are less productive

Filtering water

NTDs 3:21http://www.pbs.org/newshour/video/module_byid.html?s=news01pb88


! The 3 most common NTDsare caused by parasiticworms that live in theintestines

! Large common roundworm, Ascaris

! Afflicts 800 million people

! Whipworm – 600 million

! Hookworms – 600 million

Ascaris roundworm

Treating NTDs

! The good news: NTDs canbe treated simply andcheaply

! However WHO estimates thattreatment programs reachless than 10% of peoplesuffering from NTDs

! Strategies: fold in with other interventions! Bed nets

! Immunizations

!

Nutritional supplements such asvitamin A

Documents

L5 Child Health