Look What I Got On Summer Vacation – Giardia!

Patient Presentation
A 6-year-old male came to clinic with 5 days of diarrhea. They were loose watery stools occurring several times a day without blood or mucous. He denied abdominal pain or emesis but said sometimes he felt a little nauseous. He had recently been on vacation in the northern United States to visit his grandparents who lived on a farm with various animals and crops. He also had been swimming in 2 different lakes and had been to a family reunion potlock dinner during the past 2 weeks. He was drinking well and was urinating normally. The family wasn’t sure but maybe a cousin also had diarrhea. He had no recent antibiotic exposure. He was previously healthy and his review of systems revealed he had no fever, chills, or muscle aches.

The pertinent physical exam showed a well-appearing male in no distress. His vital signs were normal and his growth parameters were 25-50% for age. His mucous membranes were moist and he had good skin turgor. His abdominal examination showed slightly hyperactive bowel sounds. He had no abdominal tenderness, hepatosplenomegaly or masses. Genitourinary examination was normal as was his anus.

The diagnosis of diarrhea with significant exposure to potential infectious disease pathogens was made. As the patient was well hydrated, the family was counseled about prolonged diarrhea and recommendations for fluid intake and diet. A laboratory evaluation of stool studies for common bacterial pathogens along with stool for ova and parasites, Giardia and Clostridium difficile was made. The stool was positive for giardia and he was treated with Flagyl®. The diarrhea improved and repeated cultures were negative. The cousin had diarrhea but his resolved and he was not tested.

Discussion
People often don’t think that developed countries have parasitic diseases but this is not true. The major parasitic infections endemic in the United States can be thought of as:

  • Intestinal parasitic infections
    • Seen throughout the US but especially in the northern states during the summer
    • Often occur through recreational water use
    • Cryptosprodiosis, Dientamoebiasis and Giardiasis are the most common.
  • Neglected tropical diseases
    • Seen especially in the southern states (especially Texas) and are linked to extreme poverty
    • Chagas disease, Cutaneous Leishmaniasis, Toxocariasis, and Toxoplasmosis are the most common.

Learning Point
Giardia intestinalis (also known as Giardia lambia or Giardia duodenalis) is considered a zoonotic disease sometimes known as Beaver Fever. It was one of the first organisms Antonie van Leewenhoek saw under the microscope. It is a flagllated protozoan found globally that usually affects the cells in the duodenum and jejunum. It is most commonly found in children ages 1-9 years old. The number of cases is slightly decreasing in last few years in the U.S. with about 16-19,000 cases depending on the year. Cases cluster often in the northern states in the summer. Contaminated water and fecal-oral contamination of the cysts spread the disease. The cysts are difficult to kill as they are chlorine tolerant. Cysts can be killed by boiling water for more than 1 minute, or using a filter with an absolute pore size of 1 micron or smaller to remove the cysts. Incubation is 9-15 days.

The disease can be asymptomatic, have mild to severe diarrhea. Other symptoms can include anorexia, bloating, abdominal pain and cramping and explosive diarrhea. Unfortunately about 50% of patients may not clear the organisms and have chronic disease which may include anorexia, malabsorption, diarrhea and weight loss which can last years. Giardia should be considered when diarrhea lasts more than 3 days in the appropriate setting. Routine ova and parasite tests may not test for Giardia so specific testing should be ordered. Testing is by direct fluorescent antibody testing of the stool. Giardia is not continually shed and therefore 3 negative stool tests from different days are considered the standard for a negative test. Treatment is usually with nitroimidazole compounds such as metronidazole (Flagyl®), ornidazole, secnidazole or tinidazole. Other treatments are available to try if there is initial treatment failure.

Questions for Further Discussion
1. For what indications do you consider testing for stool pathogens?
2. When do you consider testing for Clostridium difficile?
3. What is in the differential diagnosis of diarrhea? Click here

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Giardia Infections and Parasitic Diseases.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Muhsen K, Levine MM. A systematic review and meta-analysis of the association between Giardia lamblia and endemic pediatric diarrhea in developing countries. Clin Infect Dis. 2012 Dec;55 Suppl 4:S271-93.

Barry MA, Weatherhead JE, Hotez PJ, Woc-Colburn L. Childhood parasitic infections endemic to the United States. Pediatr Clin North Am. 2013 Apr;60(2):471-85.

Painter JE, Gargano JW, Collier SA, Yoder JS; Centers for Disease Control and Prevention. Giardiasis surveillance — United States, 2011-2012. MMWR Suppl. 2015 May 1;64(3):15-25.

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital

What Are Some of the Classes of Environmental Pollutants Affecting Children?

Patient Presentation
A 6-month-old female came to clinic for her health supervision visit. She was sitting up, making vowel and some consonant sounds and loving playing with toys she could put into her mouth. Her mother said that she continued to nurse well but was very interested in people eating foods and wanted to know when she could start solid foods. The past medical history showed an uneventful pregnancy and delivery. The infant was fully immunized.

The pertinent physical exam revealed a playful infant with growth parameters around the 25%. During the exam she showed that she could roll both ways, sit without difficulty and had no head lag. She said “m” and “b” sounds and the rest of her examination was normal. The diagnosis of of a healthy infant was made. The pediatrician recommended starting solid foods by introducing thinned cereals or other easily swallowed foods one at a time to allow for any potential allergies. The mother had been reading about potential arsenic in rice cereal and asked what types of cereal she could use. The pediatrician offered, “her most important food now is breastmilk, but learning to eat a variety of foods is also important. In addition to rice cereal there are also barley, oat and multigrain cereals that you can use. Check to make sure the cereals are iron-fortified. She is getting some iron from the breastmilk but it isn’t enough anymore for her. She needs more and cereals are usually the way for her to get that.” She went on, “just take a small amount of the cereal and thin it with breastmilk, or water and try it with a spoon. She how she does and over time you can thicken it more as she learns.”

Discussion
Children are particularly susceptible to heavy metals in the environment and while arsenic is not regarded as a heavy metal by chemists (it is a semi-metal) it is often lumped in with mercury and lead because all have similar toxic affects. Elemental arsenic is not toxic itself, but inorganic and organic compounds are toxic. Inorganic compounds are particularly toxic because they are highly lipid soluble. Arsenic sources include water, air, marine animals, and fossil fuels. Fruits, vegetables, milk and rice can also be contaminated. As rice plants grow they can absorb more arsenic than some other grains. The American Academy of Pediatrics recommends, “Parents commonly feed infants rice cereal as a first food, but other foods are equally acceptable as a first food. Finely chopped meat provides a source of iron. Cereals made from other grains may be given first, or vegetable purees. For older children, the advice is the same: A varied diet will decrease a child’s exposure to environmental toxins in any one food, while providing a wide variety of nutrients.” To learn more about environmental arsenic, click here.

Learning Point
Environmental pollution includes those that are more traditional such as air or water pollution, but also include more modern problems including toxic chemicals, climate change, and e-waste. Environmental pollution is a large contributor to morbidity and mortality for the fetus, children and adults.

  • Air Pollution
    • Air pollution both outside and inside the home has health affects.
    • Main problems are ozone, nitrogen oxide and particulate matter.
    • Problems include respiratory disease, cancer and neurodevelopmental problems
    • Can be transported across large areas because of dispersal (outdoor) or concentrated (indoor) where solid fuel cookstoves and fires increase particulate matter substantially.
      Tobacco products and their smoke also are large contributors to respiratory diseases.
  • E-waste
    • There is rapidly increasing amounts of electronic waste or e-waste.
    • Hazardous materials include barium, cadmium, lead, lithium, mercury, nickel, flame retardants and organic pollutants such as polychlorinated biphenyls (PCBs).
    • There are also many e-waste components which are recycled and therefore exposure to these other chemicals often takes place then. Children are used in the e-waste recycling industry.
  • Climate change
    • Can cause direct effects such as heat stress, air pollution, increase in infectious diseases (diarrhea and vector-borne diseases), and extreme weather events.
    • Indirect effects include water insecurity (including increased water salinity), malnutrition, and population displacement.
  • Heavy Metal Pollution
    • See above
  • Pesticides
    • Are chemicals that are made to kill or repel living things therefore are designed to be toxic.
    • While many chemicals have been abandoned, others believed to be less toxic are still necessarily used.
    • Over time, adverse problems of many of these compounds become known or better understood. For example, organochlorine pesticides have been associated with chronic health problems and glyphosate may be carcinogenic.
    • Regulations are not consistent world-wide and storage and use locally can be problems. Use in homes is one of the major exposures.
  • Water Pollution
    • Microbial contamination continues to be a problem where consistent safe drinking water is not available.
    • Other contaminants include lead (neurotoxic effects), nitrates (causing methemoglobin), and perchlorate (inhibits iodine uptake). Radionuclides and arsenic can also be problems in addition to local contaminations from chemicals and pesticides.

Questions for Further Discussion
1. What environmental pollution risks do you have in your local environment?
2. How do you counsel your patients and families to mitigate these potential risks?
3. How do you counsel your families to start solid foods?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Environmental Health

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

American Academy of Pediatrics. AAP Offers Advice For Parents Concerned About Arsenic in Food. Available from the Internet at https://www.aap.org/en-us/about-the-aap/aap-press-room/pages/AAP-Offers-Advice-For-Parents-Concerned-About-Arsenic-in-Food.aspx (rev. 9/6/13, cited 5/2/16)

Vieira SE. The health burden of pollution: the impact of prenatal exposure to air pollutants. Int J Chron Obstruct Pulmon Dis. 2015 Jun 10;10:1111-21.

Suades-Gonzalez E, Gascon M, Guxens M, Sunyer J. Air Pollution and Neuropsychological Development: A Review of the Latest Evidence. Endocrinology. 2015 Oct;156(10):3473-82.

Miller MD, Marty MA, Landrigan PJ. Children’s Environmental Health: Beyond National Boundaries. Pediatr Clin North Am. 2016 Feb;63(1):149-65.

AAP Welcomes FDA Announcement on Limiting Arsenic in Infant Rice Cereal. Available from the Internet at https://www.aap.org/en-us/about-the-aap/aap-press-room/Pages/AAP-Welcomes-FDA-Announcement-on-Limiting-Arsenic-in-Infant-Rice-Cereal.aspx (rev. 4/1/16, cited 5/2/16).

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital

What Are The Most Common Pediatric Cancers?

Patient Presentation
A group of residents were discussing some of the patients they were caring for on their hematology/oncology rotation. They noted that it had been a very busy rotation with several children needing to be admitted with fever and neutropenia, or problems with their central intravenous catheters that were used for their treatments, and the usual number of children who were being admitted for their routine chemotherapy treatment. “Unfortunately we’ve also had a several patients with new diagnoses too. There was one child with ALL, another with rhabdomyosarcoma and another with a brain tumor. They are all so different to treat and think about so we’ve been learning a lot this month about oncology,” one resident remarked.

Discussion
Cancer occurs in all ages including children. Fortunately cancer is much less common in the pediatric age group accounting for <1% of all cancers yearly in the US. Approximately 10,000 US children under age 15 will be diagnosed with cancer in 2016. More than 80% of those children will survive more than 5 years because of advances in direct cancer treatment and treatment of its complications. Survival rates depend on a number of factors including the type of cancer and location. Despite these good numbers, about 1250 children in the US die yearly from pediatric cancer. After accidents, childhood cancer, suicide/homicide and congenital abnormalities cause similar numbers of deaths in children and teens. Known risk factors are few but include certain genetic mutations or syndromes and ionizing radiation. The World Health Organization does keep data on pediatric cancer worldwide but it is not as consistently available worldwide.

Learning Point
The most common pediatric cancers in the U.S. are:

  • Leukemia
    • 30% of all pediatric cancers
    • Acute lymphoblastic leukemia(ALL) and acute myeloblastic leukemia (AML) are the most common leukemias
    • Found in all ages
    • 5 year survival rate is 85% (all survival rates listed here are from 2005-2011)
    • 5 year survival rate is 89% for ALL and 65% for AML
  • Brain and other central nervous system tumors
    • 26% of all pediatric cancers
    • Can occur in all central nervous system locations but are a little more common in the cerebellum and brain stem than in adults
    • Found in all ages
    • 5 year survival rate is 72%
  • Neuroblastoma
    • 6% of all pediatric cancers
    • Can occur in all areas of peripheral nerves but are more common in the abdomen
    • Common in infants and young children. Rare after age 10 years
    • 5 year survival rate is 78%
  • Wilms tumor (or nephroblastoma)
    • 5% of all pediatric cancers
    • Occurs in one or both of the kidneys
    • Common in toddlers and preschoolers. Uncommon after age 6 years
    • 5 year survival rate is 92%
  • Lymphoma (including both Hodgkin and non-Hodgkin)
    • Hodgkin lymphoma is 3% of all pediatric cancers
      • Occurs in lymph nodes
      • Common in adolescents and young adults, with another peak in mid 50s. Rare in children < 5 years.
      • 5 year survival rate is 98%
    • Non-Hodgkin lymphoma is 5% of all pediatric cancers
      • Occurs in lymph nodes
      • Can occur in all pediatric ages but less common in those < 3 years of age
      • 5 year survival rate is 89%
  • Rhabdomyosarcoma
    • 3% of all pediatric cancers
    • Soft tissue sarcoma is most common.
    • Can occur in any location with skeletal muscle. Occurs in all ages
    • 5 year survival rate is 69%
  • Retinoblastoma
    • 2% of all pediatric cancers
    • Can occur in one or both eyes
    • Often occurs around 2 years of age and is uncommon after age 6 years
    • 5 year survival rate is 97%
  • Bone cancer (including osteosarcoma and Ewing sarcoma)
    • 2-3% of all pediatric cancers
    • Osteosarcoma (2%) is the most common bone tumor. Ewing’s sarcoma is also common (1%).
    • Adolescents more commonly have bone tumors but they can occur at any age.
    • 5 year survival rate for osteosarcoma is 69%

Questions for Further Discussion
1. What type of followup care do survivors of pediatric cancer need?
2. How common are second malignancies after treatment for pediatric cancer? For an answer click here
3. Where can comprehensive cancer centers for pediatric treatment be found?
4. What are PDQ®s for cancer? For an answer click here

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Cancer in Children.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

American Cancer Society. What are the most common types of childhood cancers?
Available from the Internet at ancer.org/cancer/cancerinchildren/detailedguide/cancer-in-children-types-of-childhood-cancers (rev. 1/27/16, cited 4/25/16).

Centers for Disease Control. 10 Leading Causes of Death by Age Group, United States 2014.
Available from the Internet at http://www.cdc.gov/injury/images/lc-charts/leading_causes_of_death_age_group_2014_1050w760h.gif (rev.2/25/2016, cited 4/25/16).

American Cancer Society. Cancer Facts and Figures 2016.
Available from the Internet at http://www.cancer.org/acs/groups/content/@research/documents/document/acspc-047079.pdf (rev. 2016 cited 4/28/16).

Centers for Disease Control. United States Cancer Statistics Childhood Cancer. Available from the Internet at https://nccd.cdc.gov/uscs/ChildhoodCancerData.aspx (cited 4/28/16).

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital

How Can Melatonin Be Used to Help Sleep?

Patient Presentation
A 20-year-old male came to clinic because of several nights of insomnia. He had several nights where he suddenly significantly changed the time he normally went to sleep, and then for the next 5 evenings when he could restart his normal bedtime, he had a hard time being able to initiate sleep. “I just sit there with my eyes wide awake and just can’t fall asleep,” he said. “I finally get to sleep about 4 hours later and then I can’t get up in the morning. When I do wake up I’m too scared to drive to my college classes,” he related. He denied any depression or anxiety. He said he had normal stress about his classes but was doing well. He was studying software engineering and therefore was often using electronic devices up until the time he went to bed. He denied any medications or drug use. He said that sometimes eating some food would help him fall asleep but a bigger meal made it worse. The past medical history showed a healthy male, who had previous episodes of a similar sleep problem that generally stopped after 1-2 nights. The family history showed some diabetes, and occasional insomnia in the father. There was no history of mental health problems. The review of systems was normal.

The pertinent physical exam showed a healthy male with normal vital signs and physical examination. The diagnosis of a short term sleep-onset problem was made. The patient was counseled to improve his sleep hygiene with careful attention to his schedule and also the amount of screen use he had. “Because you are using computers for school and will be for work, you are going to have to be very aware of the amount of the use, and the timing of the use, as you seem to be more prone to this sleep problem. Having a bedtime routine where you can stop the computers, maybe read or listen to music for a little while in a chair or couch and then go to your bed will probably help,” the pediatrician counseled. “Your bed should be for sleeping and not for other things like coding and homework. You can also try drinking something warm, making sure there is low-lighting in the room,” he added. “Since you are already having a problem you can also try some melatonin for a few days as a sleep aid. You should take it 2 hours before you want to fall asleep and you can do it for about a week if you need to. If it is not working call me. If this happens again, try restarting your schedule and sleep practices, and if needed you can try the melatonin again,” he said.

Discussion
Sleep is regulated by the homeostatic sleep drive and the circadian system which controls periods of activity and inactivity throughout the day. The circadian rhythm is slightly longer than 24 hours in humans and is controlled by the hypothalmic suprachiasmatic nucleus. When the circadian system and the external environment are misaligned, such that sleep occurs outside of normal times, a circadian rhythm sleep disorder can occur.

Everyone experiences disturbances of sleep throughout their lifetime. During adolescence, there is a normal physiologic change so that there is a shift to a later sleep phase for adolescents. Adolescents also commonly have inadequate sleep that occurs on an ongoing basis because of societal norms of having to awaken early in the morning. Pediatric insomnia is defined as “repeated difficulty in sleep initiation, duration, consolation, or quality that occurs despite age-appropriate time and opportunity for sleep and results in daytime functional impairment for the child and/or family.” Mild or transient problems are not a sleep disorder or insomnia. The problem must be more consistent, and be developmentally inappropriate.

Adolescents and young adults can have circadian rhythm problems occur.

Delayed sleep phase disorder (DSPD) is the most common in this group with a the prevalence of 7-16%. DSPD delays sleep onset by 3 to 4 hours compared to usual normative evening time (i.e. 10-11 PM). If left alone, the sleep is normal in quality and duration. Sleep wakening is then necessarily delayed causing problems with social needs (e.g. not getting up in time to go to school). The adolescent then has inadequate sleep which then leads to poor sleep hygiene which helps to change the intrinsic circadian rhythm which continues to cause the delayed sleep onset. Overtime, DSPD develops. DSPD is treated using good sleep hygiene but other interventions may be necessary.

  • Chronotherapy delays sleep onset progressively over several days until the normal sleep onset time is achieved and then anchors that new time with post-sleep morning light.
    Light therapy especially in the morning can be helpful.

  • Light in the evening delays sleep onset and light in the morning advances it (i.e. makes it earlier in the evening the next night). Light intensity between 2500-10000 lux will advance circadian rhythms.
  • Melatonin can also be used.

Sleep hygiene including establishing regular sleep routines and timing that can be consistently adhered to (both for sleep onset and duration), limiting technology devices especially those with a blue screen such as television and computers, limiting caffeine and energy-dense food before bedtime, regular exercise during the day and not in the evening and treatment for any underlying problems such as depression or anxiety.

Psychophysiologic insomnia (PPI) is a sleep-onset disorder and is not a circadian rhythm sleep disorder. Individuals have a very hard time initiating sleep and then difficulty in wakening in the morning. PPI and DSPD can be concurrent.

To learn more about circadian rhythms in newborns click here and a review of sleep hygiene for infants can be found here.

Learning Point
Melatonin is an indolamine that is made in the pineal gland and has chronobiotic and hypnotic properties. It also has anti-inflammatory, antioxidant and free radical scavenging abilities. Circulating endogeneous levels are high in childhood and decrease during puberty. It is metabolized by the liver and has a half-life of 45-60 minutes. Medications such as oral contraceptives and cimetidine decrease melatonin metabolism and carbamazepine and ompeprazole can increase melatonin metabolism. In humans endogenous melatonin starts to rise about 2 hours before sleep onset and peaks about 5 hours after sleep onset.

It can be used to help re-entrain short-term or long-term circadian rhythm problems or be used to help prevent sleep disruption following environment insults. It has also been used to treat headaches and seizures.

  • For PPI, melatonin is taken 2 hours before desired sleep onset as a soporific (weak sleep aid). Dosages vary but 0.2-0.5 mg can be used as a starting point.
  • For DSPD, melatonin is taken 5 hours before desired sleep onset to help retrain the system. Dosages vary but small doses have been found to be as effective. For children a 0.2-0.5 starting dose or 0.5- 1 mg in adults, which can be increased by 0.2-0.5 mg weekly until desired effect with a maximum of 3 mg in children/teens 40 kg is one regimen. Once a consistent, desired bedtime is achieved, smaller dose (such as 0.2-0.5 mg) given 2 hours before desired sleep onset helps to establish the circadian pattern.
  • For jet lag in adults 3 mg is often prescribed.
  • In children with long-term insomnia such as those with neurological disease can benefit. Melatonin should be re-evaluated at not less than 1 month after starting to determine effectiveness. Melatonin treatment is recommended to be stopped for at least 1 week yearly to again evaluate need for ongoing treatment.
    Long-term therapy can be stopped just before or after puberty.

Melatonin is considered safe but side effects can include drowsiness, headache, hypothermia, dizziness, diarrhea, enuresis, and rash.

Questions for Further Discussion
1. What health problems are associated with inadequate sleep? For a review click here.
2. What sleep hygiene recommendations do you offer families?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Sleep Disorders

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Bartlett DJ, Biggs SN, Armstrong SM. Circadian rhythm disorders among adolescents: assessment and treatment options. Med J Aust. 2013 Oct 21;199(8):S16-20.

Reiter J, Rosen D. The diagnosis and management of common sleep disorders in adolescents. Curr Opin Pediatr. 2014 Aug;26(4):407-12.

Meltzer LJ, Mindell JA. Systematic review and meta-analysis of behavioral interventions for pediatric insomnia. J Pediatr Psychol. 2014 Sep;39(8):932-48.

Bruni 0, Alonso-Alconada D, et.al. Current role of melatonin in pediatric neurology: clinical recommendations. Eur J Paediatr Neurol. 2015 Mar;19(2):122-33.

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital