Children, like the elderly and those with lowered immunity, are particularly susceptible to emerging infections. As Nobel Laureate Dr.Lederberg has stated The microbe that felled one child in a distant continent yesterday can reach yours today and seed a global pandemic tomorrow. It is clear that emerging infections know no boundaries, can affect anyone, at any age, anywhere, regardless of lifestyle, culture, ethnicity or socio-economic status.
What are some of the factors which have contributed to emerging infectious disease threats in children?
Societal changes such as day care
The expanding use of child care facilities have contributed to the emergence of infectious disease that threaten children. The number of children attending child care facilities has increased in the last decade as mothers of young children have increasingly entered the work force. There are over 10 million children in North America that attend day care and all are at risk for enteric infections such as hepatitis A, cryptosporidiosis and giardiasis; respiratory illnesses ; and middle ear infections. Often these illnesses are carried home and transmitted to other members of the household.
Food borne illnesses, food processing and packaging
Children enjoy eating hamburgers in fast food restaurants. In early 1993 hamburger meat served at a fast food restaurant chain in the USA was found to be contaminated with E.Coli 0157:H7 (93 restaurants were implicated) causing a multistate outbreak of severe bloody diarrhea and serious renal disease (hemolytic uremic syndrome). Over 500 children and adults became ill and four children died. Infectious agents continue to contaminate food supplies as evidenced by recent outbreaks of serious diarrhoeal illnesses (e.g. Salmonella) associated with consumption of raw milk, domestic cheese, eggs, and commercial airline food..
Contaminated municipal water
In April 1993 contamination of a municipal water supply in Milwaukee, Wisconsin caused the largest outbreak of waterborne illness in the history of North America. Over 400,000 thousand adults and children were infected with Cryptosporidium parvum, 4000 of whom needed to be hospitalized. More recently in 1996, Cryptosporidium has been found in the drinking water in Collingwood, Ontario.
Lack of surveillance
Lack of surveillance and limited availability of appropriate diagnostic tests have made it difficult to prevent outbreaks. Both E. Coli 0157:H7 and Cryptosporidium were first recognized as significant human pathogens in the early 1980’s but neither has received adequate public health attention.
New technology or products
The superabsorbent-tampons have resulted in the evolution of toxic shock syndrome [Staphylococcus aureus toxin producing strains] in adolescents and young adults.
Global travel
Emerging infectious disease threats from abroad are increasing due to the frequency of travel. Cholera has recently returned to the western hemisphere in epidemic proportions. In 1993, 900,000 cases of infection were detected and more than 8,000 people died.
What role has antimicrobial drug resistance played in the emergence of infectious diseases?
Antimicrobial resistance as a factor in the emergence of infectious disease warrants considerable emphasis. Antibiotics that once seemed invincible are losing their effectiveness for a wide range of community acquired infections. Pneumococcal infections are a leading cause of otitis media, pneumonia and meningitis in children. There has been an alarming increase in pneumococcal antibiotic resistance thought to be partly due to prescribing antibiotics without proper indications, prescribing the wrong drug or wrong dose or having poor patient compliance with treatment regimens.
What is the most common emerging infectious disease in North America?
Acquired immunodeficiency disease (AIDS) is now thought to have infected over 500,000 people in North America. World -wide there are thought to be approximately 1.5 million children affected by HIV. Approximately 75% of these are preventable. Effective treatment and prevention programs administered to pregnant women can decrease the transmission rate to newborns by between 50%-70%.
What are the most recently recognized emerging infections that affect children?
Emerging infectious diseases are diseases of infectious origins whose incidence in humans has increased within the past two decades or threatens to increase in the near future. The following are some of the most recently described emerging infectious diseases affecting children.
| 1976 | Cryptosporidium parvum | Diarrhoea |
| 1977 | Ebola virus | Hemorrhagic fever |
| 1977 | Campylobacter jejuni | Diarrhoea |
| 1981 | Staphyloccocus (toxin producing) | Toxic shock syndrom |
| 1982 | E. Coli 0157:H7 | Hemolytic Uremic Syndrome |
| 1983 | HIV | AIDS |
| 1983 | Helicobacter pylori | Gastritis, ulcer |
| 1988 | HHV-6 | Roseola subitum |
| 1989 | Hepatitis C | Non-A, non-B hepatitis |
Children and Ebola?
Less than 10% of all Ebola cases affect children under the age of 17 years. The reason for this sparing of children is thought to be due in part to their family members deliberately shielding them from exposure to sick and dying relatives. The adult population affected were considered to be “immunologically naive” without significant protective antibody. The risk of secondary infection was highest in family members who were in contact with patients’ blood, stool or vomit.
Children and Cryptosporidium?
Cryptosporidium infection may be asymptotic or may cause watery diarrhoea, stomach cramps and vomiting. In healthy children the condition is self limiting in 5 - 10 days and is managed with fluid replacement. Young infants, the elderly and those with weakend immunity may have a more chronic or severe course.
What can individual physicians do to diagnose, treat and prevent emerging infections in children?
Promotion of vaccination should be the mandate of every physician since this is the single most useful public health measure in the history of medicine that has been able to curtail serious infectious disease. Physicians should be on the alert for screening new immigrants and adopted babies and children who might come from areas where health care lacks any quality control. To prevent diseases caused by food borne infections such as E.Coli 0157:H7, parents should be instructed to cook all ground beef or hamburger meat properly and to avoid raw milk and milk products. Municipal water should only be consumed if adequately treated with chlorine or other effective disinfectants. Physicians should decrease the use of antibiotics whenever possible. The fact that we live in a “global village” should be a reminder to physicians that they should always be on the lookout for Malaria, Cholera, Lyme disease etc. A travel history should be part of the history of every individual with pote ntial infectious disease encountered by the physician.
Finally, some perspective
It must be pointed out that among infectious diseases, the real worldwide killers are not Ebola which killed 244 people in 1995 or Plague which claimed 500 lives, but pneumonia and gastroenteritis which killed over 7 million children under 5 years of age, and TB which killed over 2.5 million children and adults.