Symptoms of Anthrax in Children May be More Varied than Previously Thought
By Jennifer Nuzzo, SM, September 14, 2007
A review of data from more than a century of pediatric anthrax case reports suggests that the clinical presentation of anthrax among pediatric patients may be more varied that previously recognized.
A study published in the September issue of Archives of Pediatrics & Adolescent Medicine represents the “first published synthesis of the literature describing the spectrum of clinical anthrax in children.” The authors point out that, although “children will likely be among the victims of future bioterrorism attacks on the general public,” most anthrax diagnosis and treatment guidelines published since 2001 “have not specified diagnostic and management protocols for children.” 1
Bravata and colleagues reviewed the medical literature for anthrax case reports published between 1900 and 2005 in persons younger than 18 years of age. Of the 2,499 English and foreign language articles identified in their search, 73 case reports met the inclusion criteria. They examined each of these articles and classified the cases according to the presumed source of exposure. Among the 73 articles, they identified:
5 cases of inhalational anthrax
22 cases of gastrointestinal anthrax
37 cases of cutaneous anthrax
6 cases of primary meningoencephalitis
3 cases of anthrax with atypical presentations (i.e. naso- or laryngopharyngeal anthrax)1
The authors note that the total number of cases included in this study was small, and this hinders the ability to make definitive conclusions. Nevertheless, a review of the data from these 73 pediatric cases is suggestive of “4 key findings”:
Children with anthrax may present with a wider range of clinical symptoms than previously recognized and which may not track with those observed in adult patients. Although the number of cases were small, children with inhalational anthrax experience mostly fever and respiratory signs and symptoms. The authors found no evidence that children with inhalational anthrax experience altered mental status or coma, “which are key symptoms that have been shown among adults to distinguish inhalational anthrax from more common illnesses, such as influenza.”
“Mortality rates among children with inhalational and gastrointestinal anthrax and anthrax meningoencephalitis” are high, possibly higher than that observed in adult populations. Specifically, children younger than 2 years “had the highest observed mortality.” Moreover, mortality rates among children with gastrointestinal anthrax were higher than those typically observed in adults (65% versus 40%). The authors point out that the significance of this finding is not clear, as most cases included in the analysis received penicillin-based antibiotics—treatment which is not consistent with current guidelines.
The number of pediatric anthrax cases varies by age and gender. The authors found that anthrax “is reported relatively rarely in the youngest children and in girls (only 24% of the included cases).” The authors suggest that higher rates among older boys may result from greater opportunity for occupational exposure to anthrax among this population, as they are more likely to be involved in wool and butchery trades. On the other hand, the authors also suggest that underreporting or underdiagnosis of anthrax in certain age and gender groups may also be a factor.
There is no evidence to “support or refute the claim that children may be less susceptible to anthrax infection.” Although some have pointed to the absence of pediatric cases in the 1979 Sverdlovsk anthrax outbreak as evidence that children are less susceptible to infection with anthrax, the researchers did not find evidence of such, and they suggest that the paucity of data surrounding pediatric anthrax may reflect reduced opportunities for exposure, as well as underreporting or underdiagnosis of anthrax in children, rather than reduced susceptibility.1
The authors conclude that the “broad spectrum of clinical presentations in children with anthrax and the similarity of many of these presenting symptoms to other common pediatric infectious diseases pose serious challenges to current diagnostic criteria and surveillance systems.” Moreover, they maintain that the high mortality rates observed among pediatric anthrax patients underscores the importance of “rapid diagnosis and initiation of effective therapies for this population.” However, the authors conclude that “more research is needed to clarify the optimum management” of anthrax in children.1
Bravata DM, Holty JC, Wang E, Lewis R, Wise PH, McDonald KM, Owens DK. Inhalational, gastrointestintal, and cutaneous anthrax in children. Archives of Pediatrics & Adolescent Medicine. 2007;161(9):896-905. http://archpedi.ama-assn.org/cgi/content/full/161/9/896. Accessed September 6, 2007.
Jennifer Nuzzo is a Senior Analyst at the Center for Biosecurity and a Managing Editor of the weekly Biosecurity Briefing.