Asymptomatic Malaria and Other Infections in Children Adopted from Ethiopia, United States, 2006–2011

Senait M. Adebo, Judith K. Eckerle, Mary E. Andrews, Cynthia R. Howard, and Chandy C. John

Author affiliations: Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA (S.M. Adebo); University of Minnesota, Minneapolis, Minnesota, USA (J.K. Eckerle, M.E. Andrews, C.R. Howard, C.C. John); Indiana University, Indianapolis, Indiana, USA (C.C. John)

Abstract

We screened 52 children adopted from Ethiopia for malaria because they had previously lived in a disease-endemic region or had past or current hepatomegaly or splenomegaly. Seven (13.5%) children had asymptomatic malaria parasitemia by microscopy (n = 2) or PCR (n = 5). Our findings suggest that adoptees at risk for asymptomatic malaria should be screened, preferably by PCR.

International adoptees are at increased risk for infectious diseases (1). During 2007–2012, Ethiopia was 1 of the top 5 countries of origin for children who were adopted by persons in the United States (2), but few studies have been published on children from Ethiopia who were adopted by persons in the United States (3). Malaria caused by Plasmodium falciparum, P. vivax, and, less frequently, P. ovale is endemic to several regions in Ethiopia (4). Children adopted from Ethiopia are often living in orphanages in Addis Ababa, an area free of malaria, at the time of their adoption, but they may have lived in a malaria-endemic area before their transfer to the orphanage. The prevalence of asymptomatic malaria parasitemia among these children is not known.

The Study

We reviewed medical records of all children adopted from Ethiopia and seen at the University of Minnesota International Adoption Clinic (Minneapolis, MN, USA) during February 2006–June 2011 for results of standard infectious disease screening tests recommended by the American Academy of Pediatrics: tuberculosis (by tuberculin skin test or, in children >5 years old, by interferon-γ release assay); intestinal parasites (fecal testing for ova, parasites, and Giardia intestinalis antigen); hepatitis B or C virus; HIV; and syphilis (5). Children were screened for hepatitis A virus at the discretion of the physician seeing the patient and for malaria by blood smear or PCR if they met screening criteria (i.e., history of living in a malaria-endemic region or a history of or current evidence of splenomegaly or hepatomegaly). The study was reviewed and approved by the University of Minnesota Institutional Review Board.

During the period studied, 255 international adoptees from Ethiopia were seen at the clinic. Adoptees’ mean age at medical evaluation was 2.8 years (range 3.4 months–14.9 years); 148 (58%) were female and 107 (41.9%) were male. All 255 children were asymptomatic for malaria, but 52 met malaria screening criteria and were tested by peripheral blood smear (n = 24), PCR (n = 24), or both (n = 4). Of the 52 children, 7 (13.5%) had blood smear (2 children) or PCR (5 children) results positive for Plasmodium species. Table 2 outlines the sensitivity, specificity, and negative and positive predictive values of medical history questions and physical exam signs for asymptomatic malaria. The 2 children with a positive blood smears had low parasite densities (<0.1%), and the species could not be identified. These 2 children were treated before PCR testing was available. Subsequently, PCR became the preferred first-line diagnostic test, and 5 infections were diagnosed on the basis of PCR results: 3 P. vivax, 1 P. falciparum, and 1 mixed P. vivax and P. falciparum. Among the 7 children with parasitemia, 2 had a palpable spleen tip, 2 had a hemoglobin level of <11 g/dL (reference 11–15 g/dL), and none had thrombocytopenia. All children with a positive blood smear or PCR result were treated: atovaquone/proguanil for P. falciparum infections, chloroquine followed by primaquine for P. vivax infections, and atovaquone/proguanil followed by primaquine for the mixed infection and infections with no species identified.

In addition to the malaria results, of 217 children tested for intestinal parasites, 96 (44.2%) had positive results; Giardia intestinalis flagellates were most common (n = 75, 34.6%), followed by Blastocystis hominis protozoa (n = 34, 15.7%) (Table 1). Evidence of tuberculous infection was found in 49 (27.1%) children, hepatitis A virus in 14 (8.7%), hepatitis B virus in 6 (2.6%), and HIV in 1 (0.5%) (Table 1).

Dr. Adebo works as a hospitalist pediatrician at the Children’s Hospital of Philadelphia. Her primary research interests are global health and international adoption issues.

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Tables

Suggested citation for this article: Adebo SM, Eckerle JK, Andrews ME, Howard CR, John CC. Asymptomatic malaria and other infections in children adopted from Ethiopia, United States, 2006–2011. Emerg Infect Dis. 2015 Jul [date cited]. http://dx.doi.org/10.3201/eid2107.141933

DOI: 10.3201/eid2107.141933