Nutrition and parasitic diseases 2020

Dr/ Hanan Mahmoud
Lecturer of Medical Parasitology
Clinical Nutrition Specialist
Faculty of Medicine
Ain shams University
Cairo, 2020
Nutrition & Parasitic Diseases

Aim of lecture:
1. To highlight Parasitic infections deleterious effects on
host nutritional status.
2. To recognize the important role that WASH sector has to
play within a strategy to combat undernutrition.
3. To understand the interactions between intestinal
pathogens, enteropathy and malnutrition in developing
countries, which drive morbidity and mortality and
hinder the long- term developmental potential of
children.

Parasitic diseases
Parasitic infections, especially those affecting intestines are
widely distributed all over the world and comprise great
health concerns, especially for children in poor regions in
Latin America, Africa, and Asia.

• Even though part of the increased reports of parasitic
disease may be due to previous underreporting, the
incidence does seem to be increasing.
• Large parts of the industrialized countries have managed
to reduce the burden of many parasites, whereas in many
countries multiple chronic infections are common.
• Most helminthic infections (95%) are zoonotic, and
protozoal infections in humans, both zoonotic and non-
zoonotic, are likely to be emerging.
• An emerging problem in parasites is increasing resistance,
which cause many drugs to be ineffective.

Factors leading to increase in the number of
susceptible individuals

Factors leading to increased exposure of infectious
disease

Factors contributing to increased infectivity

Intestinal parasitic infections

• Intestinal parasitic infections (IPIs) species are among the
most prevalent parasitic diseases in tropical and subtropical
developing countries, where they constitute a major public
health issue and socio-economic concern (WHO, 2017).
• About 3.5 billion people are infected by intestinal parasites
globally. Young children living in poor-resource settings are
particularly at risk, as these pathogens may impair their
cognitive and psychomotor development.
• In several parts of the world, Soil Transmitted Helminthes
(STH) are experiencing a significant reduction in prevalence
rates. However, beside STH infections, protozoan disease
outbreaks are being increasingly reported.

• Protozoan disease transmission typically follows the
faecal-oral route, either directly (e.g. person-to person or
animal-to-person contact) or indirectly through ingestion
of contaminated food, water or fomites.
• In this regard, preventive and control measures against
cryptosporidiosis, giardiasis or even blastocystosis should
be emphasized.
• The relationship between IPIs particularly STHs, anemia
and malnutrition have been well documented. They often
share similar geographical areas.
ResearchGate.net

• These parasites can induce intestinal bleeding and
competition for nutrients, which leads to malabsorption of
nutrients. They can also reduce food intake and ability to
use protein and to absorb fat as well as increase nutrient
wastage via vomiting, diarrhea and loss of appetite .
• These effects lead to protein energy malnutrition (PEM),
anemia and other nutrient deficiencies.
• Such nutritional effects can have a significant impact on
growth and physical development, especially among school
children and pregnant women as a result of heavy
infections.
IPIs impair the nutritional status of those
infected in many ways

• According to World Health Organization (WHO) estimates
in 2010, about 104 million children worldwide are
underweight and undernutrition contributes to about
one-third of all childhood deaths.
• Malnutrition is responsible in some way for a little more
than half (54%) of the 10.8 million deaths per year in
children < 5 years old.
Global Burden of Malnutrition

• Malnutrition is particularly lethal in combination with
infectious diseases such as malaria, measles, diarrhoeal
diseases - the major killer diseases affecting children.
• Infection and micronutrient deficiencies can induce
immunodeficiency in otherwise healthy children, increasing
susceptibility to diarrhoea and other infections.
• This can lead to a vicious cycle of repeated infections,
reduced immunity, and deteriorating nutritional status.
• Malnutrition magnifies the effect of disease, as malnourished
person has more severe disease episodes, more
complications, and spends more time ill for each episode.

Major Parasitic Diseases, their Global Prevalence, and
potential mechanisms of Nutritional Impairment

Intestinal helminthic infections

• The World Health Organization (WHO) prioritizes 17
neglected tropical diseases (NTDs), that affect over a
billion of the world’s poorest people and pose a
significant economic burden to developing economies.
• NTDs are a heterogeneous group of infections caused by
parasites (helminthes and protozoa), viruses, and
bacteria.
• What makes NTDs different from non-neglected diseases
is that these diseases are disablers rather than killers.

• Indeed, these infections are co-endemic: an individual
may be infected with more than one NTD in addition to
other well-known diseases such as HIV, tuberculosis, and
malaria.
• For example, the parasite infection schistosomiasis can
make women and girls more susceptible to HIV infection,
saps micronutrients from developing children to stunt
their growth, and renders children less likely to attend
school.

• A chronic helminthic parasite infection known as lymphatic
filariasis (LF) may reduce vaccine efficacy by broadly
modulating the immune system.
• LF causes severe swelling (lymphedema) in 40 million
people rendering them socially stigmatized and largely
unable to work.
• In addition to schistosomiasis and LF, many more NTDs are
characterized by chronic disabilities, increased
susceptibility to infectious and non-infectious diseases,
social stigma, and an economic burden on the individual,
the family, and the country.

• Producers of drugs and diagnostic tests
• Funders (control programs)
• National policy makers
• Academic centers
• Media
Neglected by whom?

• Intestinal infections in humans caused by worms. Four
species of nematodes are collectively referred to as STH:
Ascaris lumbricoides (the roundworm), Trichuris trichiura
(the whipworm) and Necator americanus or Ancylostoma
duodenale (the hookworms).
Ascaris, also known as roundworms.
Photo: James Gathany, CDC.
Rectal prolapse in child
due to whip worm
Soil-transmitted helminthiases (STH)

• STH are some of the most common infections among
humans, caused by a lack of sanitation and hygiene,
infecting around two billion people globally, while an
estimated four and a half billion people are at risk of
infection.
Polyparasitic infections can occur with whipworms, ascaris, and
hookworms, because these parasites live in similar environments.

• The burden of disease from STH is mainly attributed to
their chronic and insidious impact on the health and
quality of life of those infected rather than to the
mortality they cause.
• Infections of heavy intensity impair physical growth and
cognitive development and are a cause of micronutrient
deficiencies including iron deficiency anemia leading to
reduced work productivity in adults and adverse
pregnancy outcomes.
Ancylostoma duodenale also known as
(hookworm)

© World Health Organization 2010
Distribution of soil-transmitted helminthiases,
worldwide, 2009

Global Burden of Disease (GBD) aims to quantify the burden
of premature mortality and disability for major diseases or
disease groups, and uses a summary measure of population
health, the DALY, to combine estimates of the years of life lost
and years lived with disabilities. The data are also broken
down by age, sex and region.

• In recent decades, the burden of STH has declined
markedly: the 2016 GBD study estimated there was a 43–
78% (depending on STH species) reduction in disability
adjusted life years (DALY) caused by STH between 1990
and 2016.
• These reductions likely reflect the direct impact of a scale-
up in school or community based deworming
programmes, as well as increased access to self-
treatment.
• The relationship between nutrition and soil-transmitted
helminthiasis is complex and warrants further
investigation.

Mechanical Intestinal obstruction &
Vit A malabsorption (may be related to
the effects of infection on fat
absorption )
Geophagia!!!

Intestinal blood loss, iron deficiency, PEM

Trichuris Dysentery syndrome (chronic dysentery,
anemia, and poor growth, and, in many cases, severe
stunting and cognitive deficits)

• It includes the usage of
antihelminthic as a public health
tool to target simultaneously the
prevalent helminth infections in
the area.
• It represents a cost-effective and
easy to implement short to
medium term strategy for
eliminating morbidity associated
with STH, while improved access
to sanitation is a long-term
strategy towards the same goal.
Preventive chemotherapy

• Periodic drug treatment (deworming) to all children living
in endemic areas (once a year when the prevalence of soil-
transmitted helminth infections in the community is over
20%, and twice a year when the prevalence of soil-
transmitted helminth infections in the community is over
50%).
• The recommended drugs (albendazole 400 mg or
mebendazole 500 mg) are effective, inexpensive and easy
to administer by non-medical personnel (e.g. teachers).
• They have been through extensive safety testing and have
been used in millions of people with few and minor side-
effects.

• An intervention study conducted in western India, aimed
at school-going, 8–12-year-old children, evaluated the
effect of deworming alone vs. deworming and weekly
iron–folic acid (IFA) supplementation on growth,
hemoglobin level, and physical work capacity of their
subjects.
• As compared with only deworming medication,
deworming + IFA supplementation was more effective in
increasing the hemoglobin levels of the children, with
65% of the children converting to a non- anemic status
after IFA + deworming supplementation.

• Due to the significant connection between
schistosomiasis, hookworm and iron deficiency anemia,
iron supplements are recommended with antihelminthic
treatments to prevent against both the disease and risk of
deficiency.
• As well as this, other micronutrients are also thought to
have beneficial affects after antihelminthic drugs have
been given.
• Vitamin A is thought to be beneficial for children after
deworming to protect against anemia.
Nutritional therapy for schistosomiasis and
hookworm

• However, supplementary food is expensive, so
supplementation in the form of tablets are easier to
distribute.
• When children are at school these treatments are
easier to distribute, but children that do not attend
school are harder to access.
(Stoltzfus & Dreyfuss 1998; Hall, 2007)

Enteric pathogens that cause moderate-
to-severe diarrhea in children
The recent Global Enteric Multicenter Study (GEMS) study found that the five most common
pathogens associated with MSD and death – independent of geographic location – are
Rotavirus, Cryptosporidium species, and Shigella species, ST-ETEC, and typical
enteropathogenic E. coli.

There remains considerable debate as to whether
malnutrition is caused by multiple moderate-to-severe
diarrhea (MSD) episodes or if MSD is simply more
common in children who are malnourished
• Children exposed earliest to enteric pathogens that
cause longer duration disease and intestinal damage are
thought to be most likely to develop malnutrition.
OR
• Children who are malnourished are more susceptible to
infection, and infection can be of longer duration and
more severe than in well-nourished children.

Although Blastocystis is one of the most common enteric
parasites, there is still much controversy surrounding the
pathogenicity and potential treatment options for this
parasite!!!!!

Zoonotic
Modified Ziehl nelseen stain

• Cryptosporidium is the only enteric pathogen with
evidence showing infection leads to malnutrition
(particularly in under-1’s and under-3’s), although it is
postulated this could also be true for ETEC and Shigella
species.
• The earlier a child is reached with interventions, the
greater the chance there is of preventing malnutrition. In
malnourished children, treatment for MSD should be
aggressive.
• The physical impact infection with an enteric pathogen
has on intestinal function impacts the potential for
developing malnutrition.

Vitamin A and zinc deficiency !!!!!!!
nucleic acid amplification tests

• These changes can be induced by the activities of the
organisms themselves and by the consequences of the
host's immune response. Even relatively mild pathology
can impair digestion and absorption and lead to increased
loss of nutrients, contributing to the vicious cycle.

• The World Health Organization (WHO) estimates that 50%
of malnutrition is associated with repeated diarrhoea or
intestinal worm infections, as a result of unsafe water,
inadequate sanitation or insufficient hygiene.
Water, Sanitation and Hygiene (WASH)
Sanitation
Water Hygiene

1) Parasitic infections, such as soil-transmitted helminths
(worms) and enteric protozoa .
Interconnectedness of water and sanitation and the transmission of infectious agents of NTDs
Lack of access to WASH has a huge
impact on human health including

2) Diarrhoea (largely caused by poor WASH) is a
leading cause of death in children under-five
globally, and its constant presence in low-income
settings may contribute significantly to under-
nutrition.

3) Approximately a third of all child deaths are attributable
to nutrition-related factors, such as low birth weight,
and severe wasting, all of which are closely linked to a
lack of access to water and particularly sanitation and
hygiene.
4) Many children in developing regions suffer stunting (low
height for age) , which reflects chronic nutritional
deficiencies, and repeated ingestion of animal and
human faeces due to poor waste management and a
lack of sanitation. According to the World Bank, open
defecation accounts for most or all excess child stunting
in India.

I. Wearing shoes reduces hookworm infection by an
average of 71%.
II. Access to a household latrine was associated with
reduced risk of infection with roundworm and
whipworm by more than 40%.
Preventing Soil-transmitted Helminths
(Intestinal Worms) with WASH
Interventions

III. Hand washing with soap at critical times, such as after
defecation and before eating, can reduce risk of
infection with all three STH species by more than 30%.
IV. Households that have piped water access have a
markedly reduced risk of infection (43% to 60%),
although this may be related to other sanitation and
hygiene practices that occur due to having a water
source close to home.

• A number of studies in recent years have measured the
impact WASH interventions have on undernutrition
highlighting its impact on the reduction of certain causes
of undernutrition.
• The Cochrane review (2013) analysed data from 14 studies
and demonstrated how access to clean water and regular
use of soap resulted in a long-term increase in growth in
children aged under five, and that there was therefore a
link to their nutritional status.

• The underlying causes of undernutrition are poor sanitary
and hygiene conditions coupled to a lack of access to safe
water.
• This causal link may be expressed directly, with immediate
consequences on people’s health, or indirectly, creating a
long-term risk to people’s nutritional status.
• The process works both ways: poor nutritional status
reduces immunity and weakens the body’s natural
defences (skin, intestinal membranes), creating a
predisposition for infections (such as diarrhoea) and
entrenching undernutrition by reducing intestinal
absorption.

• A chronic disease of small intestine ccc by gut
inflammation and barrier disruption, malabsorption and
systemic inflammation in the absence of diarrhea.
• It is predominantly diseases of children in low income
countries.
• It had not been recognized as a priority health issue,
because it does not cause overt symptoms and was seen in
apparently healthy individuals.
• However, there is a growing concern of environmental
enteropathy (EE); environmental enteric dysfunction (EED),
because of its impact on longitudinal public health issues.

• Pathogenesis: Contamination of the environment leads to
increased exposure to intestinal pathogens, that damage
the mucosa and, because of failure to repair the damage,
lead to microbial translocation (can be enhanced in a
vicious cycle by the disruption of gut barrier and by the
exposure to pathogenic bacteria), inflammation/sepsis and
malabsorption.
• Several of these components reinforce mucosal damage in
a positive feedback loop, exacerbating the cycle of
malnutrition and infection.

Small intestine bacterial overgrowth (SIBO)
• Is a subclinical quantitative abnormality of bacteria in the
upper gastrointestinal tract defined by greater than 105
CFU/mL upper intestinal aspirate as assessed by both
anaerobic and aerobic cultures.
• Although SIBO is observed among patients with anatomic
abnormalities (adhesions after surgery or radiation),
inflammation (inflammatory bowel diseases and HIV
infection), and metabolic disorders (diabetes mellitus), it is
frequently seen in people living in developing countries.
• Importantly, it was also shown that SIBO is associated with
growth faltering.

• On the other hand, continuous exposure to fecal
material may induce qualitative (compositional) changes
of gut microbiota.
• Considered together, it is suggested that not only
quantitative abnormalities represented by SIBO, but also
qualitative (compositional) changes of microbiota in the
small intestine play an important role in the
development of EE/EED.
• Further studies will be required for the comprehensive
understanding of the effect of bacterial exposure on the
development of EE/EED.

SIBO, small intestine bacterial overgrowth, morphological changes, such as flattened villi and crypt
hyperplasia, It is assumed that these abnormalities are overlapping but not equitably occurring in each
case

1) Continuous exposure to feces triggers EE/EED in
individuals living in poor sanitary condition.
2) Pathogenic conditions are seen systemically as well as
locally in small intestine (black arrows).
3) Pathogenic conditions have adverse effects on children's
health as inducing long-lasting consequences (red
arrows).
4) These consequences, in turn, contribute a vicious cycle
(blue arrows).
Thus, diarrhoea, pathogen carriage, microbiota composition and
EED likely need to be addressed together to reduce malnutrition.

1) Water and sanitation (WASH) interventions to
prevent enteropathogen exposure.
Potential points for intervention

2) Antimicrobial, probiotic or prebiotic agents to
reduce gut colonization/dysbiosis.
3) Factors (still unidentified) to enhance mucosal
healing.
4) Specific micronutrient supplementation to
overcome specific absorptive defects, such as zinc
to promote Paneth cell function.
5) Anti-infective agents to reduce microbial
translocation and prevent sepsis.
6) Anti- inflammatory interventions.

The ‘‘vicious cycle’’ of enteropathogens, malnutrition, and impaired childhood
development, and multifaceted opportunities for intervention.
Figure adapted from Nutr Rev. 2008 September; 66(9): 487–505 [15].
doi:10.1371/journal.pntd.0002125.g001

• New studies indicate that the kinds of microbes living in
the gut influence the severity and recurrence of parasitic
worm infections in developing countries.
• People who have sustained infections or who experience
multiple infections have a different microbiome to start
with compared with those who do not have as much
trouble with infection.
Gut microbes and intestinal parasitic
infections

• Studying communities in Liberia and Indonesia, the
researchers found that the gut microbiomes of people
able to clear the infections without drugs were more
alike and differed markedly from the microbiomes of
those who could not clear the infections without
treatment.
• The findings suggest that manipulating the gut’s
microbial communities may protect against intestinal
parasites, which affect more than 1 billion people
worldwide.

• Suggesting some fermented food* that could alter the
microbiome and result in a decreased rate of reinfection,
rather than giving more antihelminthic drugs.
• In order to help people fight off the infection by
themselves.
• Currently, researchers are working on bacteria that are
associated with protection against infection and studying
their effects in mice with intestinal worm infections.
* Not all fermented foods qualify as probiotic, and not
all probiotics take the form of fermented foods

• Thus, taking a probiotic (live bacteria that confer health
benefits when consumed in adequate numbers) doesn’t
just add beneficial bacteria to your gut, it helps foster the
growth of the beneficial bacteria you are already having.
• Modern diets, low in fibre and high in salt, sugar and fat
tend to have a negative effect on our gut microbiomes,
encouraging the growth of more pro-inflammatory
strains such as certain E.coli strains.
• While eating a variety of high fiber plant foods such as
vegetables, whole grains and legumes provide non-
digestible carbohydrates, that drive fermentation and
keep your gut microbes happily fed.

• 500 million people live in malaria-endemic areas.
• Major cause of morbidity & mortality.
• Often affects poor and malnourished populations -
vulnerable, children & pregnant women.
• Malaria causes haemolysis, which in turn causes
anemia.
• On the basis of the prevalence of malnutrition
published by the WHO, the regions with the
highest prevalence of undernutrition are also the
areas with a high incidence of malaria.
Malaria

• Prevention:
Bednets.
Spraying.
Larvae control &
environmental
management

• Uncorrected iron deficiency leads to:
Severe anaemia (major obstetric problem;
maternal mortality).
Low birth weight risk (2x as high in malaria-
endemic area).
Stillbirths, miscarriage.
Reduced work capacity.
Diminished learning ability.
Increased susceptibility to infection.
Iron deficiency

Conflicting information……….
• Iron supplementation protects a child who is at high risk of
dying from severe anaemia in the first 2 years of life.
• The malaria parasite requires iron for its multiplication in
blood, and thus may be less infective in the iron-deficient
individual.
• However, antimalarial prophylaxis protects against severe
anemia much more.
Reduce Malaria or supplement iron?

• Evidence - Reducing malaria makes more of a difference
than iron supplementation in preventing severe anaemia.
• Better understanding of the interplay between malaria
and nutrition will improve our control strategies against
this ancient enemy.
• Targeting could be via providing iron during the dry
season, when malaria infection is less likely or a screen-
and treat approach in which a “need iron” serum marker is
rapidly assessed and used to guide supplementation—
hepcidin is just such a candidate serum marker currently
under investigation.

Interrelation between malnutrition, malaria,
and immunity
* Hematopoiesis is regulated by the proliferation, differentiation and maturation of erythropoietic
progenitor cells into erythrocytes and is tightly controlled by a complex communication network of
cytokines as signal mediators.

Parasitic diseases caused by Food
contaminants
www.foodsafetynews.com

Case report
• 9 y old boy, GCS 15 , no motor
or sensory deficit just
headache and repated vomting
for 1 month .
• 24 hydatid cyst were removed
without rupture.
• Operated in Matariah teaching
hospital in Cairo Egypt
(october,2019)

• In general, rural residents are most vulnerable to these
increases in infectious disease, whereas consumers some
distance away derive most of the benefits from increased
food production.
• To maximize human health; society must minimize the
adverse consequences of agricultural growth, while
maximizing the health benefits.

• Epidemiological surveys targeting different human
populations are highly needed in developing countries to
estimate the actual status of intestinal parasitic infections
in order to allow the implementation of appropriate
control measures, or to evaluate the impact of ongoing
programs for parasite control.
• Controlling parasitic infections would make possible
enormous progress in helping to deal with the problems of
inadequate nutrition.

• Much remains to be learned about the complexities of the
interaction between parasites and nutrition, but it seems
clear that some alteration of infection and disease status
may be possible by using dietary manipulations.
• It remains clear, however, that the first consideration is to
attempt to improve, or at least maintain, protein-energy
levels.
• Without this, the insidious effects of parasitic infections
will continue to reduce the physical and educational
potential of a very large proportion of the world's
children.

• Alongside efforts to combat STHs, we need aggressive
measures to address ‘‘stunting’’ and‘‘wasting’’ enterics
such as Cryptosporidium,E. histolytica, G. lamblia, and
other pathogens.
• Nutrition- sensitive interventions, such as WASH
interventions, are necessary to fully reduce the worldwide
burden of malnutrition.
• There is sufficient evidence (from a variety of studies) of a
link between WASH programming and nutritional
outcomes – particularly for stunting – to promote WASH as
nutrition-sensitive interventions.

• The link between WASH and nutritional outcomes is
mediated via environmental enteropathy.
• There are barriers to concurrently implementing WASH
and nutrition interventions.
• Large trials are currently being conducted to determine
the impact of combined WASH and nutrition interventions.

Dr/ Hanan Mahmoud
Medical Parasitology department
Faculty of Medicine
Ain Shams University, 11591, Cairo, Egypt.
Email: hanan.mahmoud27@hotmail.com
Mobile: 00201006770522
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Nutrition and parasitic diseases 2020

Nutrition and parasitic diseases 2020

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