Nav: Home

Children in developing world infected with parasite may be more prone

May 04, 2016

Children infected even just once with a certain type of waterborne parasite are nearly three times as likely to suffer from moderate or severe stunted growth by the age of two than those who are not - regardless of whether their infection made them feel sick, new Johns Hopkins Bloomberg School of Public Health-led research suggests.

The researchers, publishing May 4 in the journal PLOS Neglected Tropical Diseases, found that three of every four children studied in a slum on the outskirts of the capital of Bangladesh experienced at least one Cryptosporidium infection in the first 24 months of life. One in four of the 302 infected children experienced the severe diarrhea that is associated with the parasite, while the other 72 percent were infected with Cryptosporidium but had no symptoms at all.

Despite a lack of symptoms, more than half of the children experienced stunted growth in the first two years of life, leading to irreversible damage and contributing to poor cognitive development, poor educational performance and reduced earning potential in adulthood, trapping individuals in a lifetime of poverty. Worldwide, an estimated 178 million children under 5 suffer from stunted growth, primarily in lower-income countries. The spread of Cryptosporidium can be blamed on a lack of access to clean drinking water and proper toilets. It is resistant to chlorine, which is often used to clean water.

"It has been thought that the diarrhea that results from Cryptosporidium infections was causing the dehydration and malnutrition that can lead to stunted growth," says the study's leader Poonum Korpe, MD, an assistant scientist in the Department of Epidemiology at the Bloomberg School. "This study suggests that while diarrhea is certainly a problem, infection with the parasite itself - even if there are no diarrheal symptoms - is causing the malnutrition. These children don't even get sick and their growth is stunted. We think it's possible that the parasite is damaging the gut at this early age, making absorption of vital nutrients more difficult."

For the study, Korpe worked with collaborators from the University of Virginia and the International Centre for Diarrhoeal Disease Research in Bangladesh. The researchers followed 392 children from a slum called Mirpur from birth until the age of two. Twice a week, families were visited by researchers who asked questions about the child's health, monitored growth and collected blood and stool samples, which were later tested for a variety of bacteria and parasites.

According to the World Health Organization definition, children are considered stunted if their height-to-age ratio falls under what is considered the norm. The researchers found that by the age of two, nearly 30 percent of the children in Mirpur met the WHO definition for mild stunting, nearly 36 percent for moderate stunting and 21 percent for severe stunting.

While the researchers aren't certain exactly why children without diarrhea still experienced stunting, they suspect that the appearance of the larva-like parasite in the intestines may be causing permanent damage to the intestines' ability to absorb nutrients. Recent studies of programs that provide adequate food and supplementation to families in need in low-income countries have surprised researchers in that these interventions have not had the impact on malnutrition that they expected.

"Those interventions have not been as successful as we thought they would be," Korpe says. "Malnutrition is more than just an issue of food insecurity. This study suggests a possible reason why. It could be the first step in recognizing that gut infections may be the real problem. But we have a lot of work to do to figure this all out."

According to a 2008 analysis by a separate Johns Hopkins Bloomberg School of Public Health group, 21 percent of deaths in children younger than five are attributable to malnutrition worldwide.

The infection occurs all over the developing world, but there have been sporadic outbreaks in the United States, typically in the summer when a pool is contaminated with the Cryptosporidium parasite.

Korpe says that the focus needs to be on interrupting the spread of infection as well as developing vaccines and treatments.

"These children weren't born stunted," she says. "Something happened in the environment that's doing this to them."
"Natural history of Cryptosporidiosis in a longitudinal study of slum-dwelling Bangladeshi children: association with severe malnutrition" was written by Poonum S. Korpe; Rashidul Haque; Carol Gilchrist; Cristian Valencia; Feiyang Niu; Miao Lu; Jennie Z. Ma; Sarah E. Petri; Daniel Reichman; Mamun Kabir; Priya Duggal; and William A. Petri, Jr.

The study was supported by grants from the National Institutes of Health's National Institute of Allergy and Infectious Diseases (5R01AI043596 and 5K23AI108790).

Johns Hopkins University Bloomberg School of Public Health

Related Public Health Articles:

Pandemic likely to cause long-term health problems, Yale School of Public Health finds
The coronavirus pandemic's life-altering effects are likely to result in lasting physical and mental health consequences for many people--particularly those from vulnerable populations--a new study led by the Yale School of Public Health finds.
The Lancet Public Health: US modelling study estimates impact of school closures for COVID-19 on US health-care workforce and associated mortality
US policymakers considering physical distancing measures to slow the spread of COVID-19 face a difficult trade-off between closing schools to reduce transmission and new cases, and potential health-care worker absenteeism due to additional childcare needs that could ultimately increase mortality from COVID-19, according to new modelling research published in The Lancet Public Health journal.
The Lancet Public Health: Access to identification documents reflecting gender identity may improve trans mental health
Results from a survey of over 20,000 American trans adults suggest that having access to identification documents which reflect their identified gender helps to improve their mental health and may reduce suicidal thoughts, according to a study published in The Lancet Public Health journal.
The Lancet Public Health: Study estimates mental health impact of welfare reform, Universal Credit, in Great Britain
The 2013 Universal Credit welfare reform appears to have led to an increase in the prevalence of psychological distress among unemployed recipients, according to a nationally representative study following more than 52,000 working-age individuals from England, Wales, and Scotland over nine years between 2009-2018, published as part of an issue of The Lancet Public Health journal on income and health.
BU researchers: Pornography is not a 'public health crisis'
Researchers from the Boston University School of Public Health (BUSPH) have written an editorial in the American Journal of Public Health special February issue arguing against the claim that pornography is a public health crisis, and explaining why such a claim actually endangers the health of the public.
The Lancet Public Health: Ageism linked to poorer health in older people in England
Ageism may be linked with poorer health in older people in England, according to an observational study of over 7,500 people aged over 50 published in The Lancet Public Health journal.
Study: Public transportation use linked to better public health
Promoting robust public transportation systems may come with a bonus for public health -- lower obesity rates.
Bloomberg American Health Initiative releases special public health reports supplement
With US life expectancy now on the decline for two consecutive years, the Bloomberg American Health Initiative is releasing a supplement to Public Health Reports, the scholarly journal of the US Surgeon General.
Data does the heavy lifting: Encouraging new public health approaches to promote the health benefits of muscle-strengthening exercise (MSE)
According to a new study in the American Journal of Preventive Medicine, almost 75 percent of US adults do not comply with public health guidelines recommending two or more muscle-strengthening exercise (MSE) sessions a week, with nearly 60 percent of the population doing no MSE at all.
The Lancet Public Health: Moderate carbohydrate intake may be best for health
Low-carb diets that replace carbohydrates with proteins and fats from plant sources associated with lower risk of mortality compared to those that replace carbohydrates with proteins and fat from animal sources.
More Public Health News and Public Health Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Meditations on Loneliness
Original broadcast date: April 24, 2020. We're a social species now living in isolation. But loneliness was a problem well before this era of social distancing. This hour, TED speakers explore how we can live and make peace with loneliness. Guests on the show include author and illustrator Jonny Sun, psychologist Susan Pinker, architect Grace Kim, and writer Suleika Jaouad.
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.