Parasitic Infections

Intestinal Parasites

Intestinal parasites are a concern for many recently arrived refugees, including Somali refugees. From 1999 to 2016, 18% (n=15,711) of new Somali arrivals were found to be infected with at least one pathogenic parasite, with Giardia being the most common pathogen (Table 3) [42]. Infection rates were highest among Somali refugees who arrived from 1999 to 2004 (25%) [42].

Table 3: Ova and Parasite (O&P) Testing Results among Somali Refugees in Minnesota, 1999–2016

Ova and Parasite (O&P) Testing Results among Somali Refugees in Minnesota, 1999–2016
Screening Result for Intestinal Parasites Year of US Arrival
1999–2004 2005–2010 2011–2016 1999–2016
Screened 5864 6496 3351 15711
No Pathogenic Parasites Found 4410 (75%) 5568 (86%) 2765 (83%) 12947 (82%)
Pathogenic Parasite(s) Found 1454 (25%) 928 (14%) 586 (17%) 2764 (18%)
Giardia 305 (5%) 411 (14%) 395 (12%) 1111 (7%)
Trichuris 507 (9%) 265 (4%) 9 (<1%) 781 (5%)
Entamoeba histolytica 168 (3%) 171 (3%) 117 (3%) 456 (3%)
Hymenolepis 81 (1%) 75 (1%) 45 (1%) 201 (1%)
Dientamoeba 13 (<1%) 63 (1%) 56 (2%) 132 (1%)
Other Pathogenic Parasites** 51 (1%) 29 (<1%) 26 (1%) 98 (1%)

Source: Minnesota Department of Health [42]
*Percent of those screened
**Includes Ascaris, Cryptosporidium, Cyclospora, Diphyllobothrium, hookworm, Fasciola, pinworm, Schistosoma, Strongyloides, and Taenia

Soil-transmitted infections (ascariasis, trichuriasis, and hookworm) are common among refugees, and most refugees receive presumptive albendazole treatment prior to departure. Strongyloidiasis and schistosomiasis are of particular concern due to high prevalence, risk of morbidity and mortality, and long latency or infection periods. In a cohort (n=100) of US-bound Somali Bantu refugees, 73% tested seropositive for schistosomiasis, with the majority of cases caused by Schistosoma haematobium. Additionally, 23% tested seropositive for strongyloidiasis, and 21% of all individuals tested seropositive for both schistosomiasis and strongyloidiasis. In this cohort, age was associated with increased risk of infection, with adults (≥18 years of age) being 3 times more likely to be seropositive for schistosomiasis. Additionally, individuals ≥30 years of age were 2.5 times more likely to be seropositive for strongyloidiasis than those <30 years of age [46]. Before arrival in the United States, most Somali refugees receive presumptive treatment for Strongyloides (ivermectin) and schistosomiasis (praziquantel). Somali refugees who have lived in or are departing from areas endemic for Loa loaExternal do not receive ivermectin before departure, due to risk of encephalopathy. However, most Somali refugees receive ivermectin, as Somalia and most countries where Somali refugees are processed are not endemic for Loa loa.

Screening data from the Minnesota Department of Health indicate that ~2% of Somali refugees screened (n=4,870) had a positive strongyloides serology after arrival, suggesting the effectiveness of the presumptive treatment program [42]. Similarly, there was a noticeable decrease in schistosomiasis prevalence after arrival. At domestic screening, 4% of Somali refugees screened (n=2,578) had positive schistosoma serologies [42]. Among Somali refugees, the most common clinical presentation for schistosomiasis is asymptomatic hematuria, either gross or microscopic. However, schistosomiasis can cause a broad range of signs and symptoms. Schistosomiasis should be considered in any individual of Somali descent who has lived in or visited endemic areas and presents with, or is found to have, hematuria or any unexplained symptoms [47].

Malaria

Malaria is endemic in the Horn of Africa, including southern Somalia and in countries where Somali refugees are being processed for resettlement. However, prevalence among new arrivals is very low. US-bound Somali refugees are presumptively treated with artemether-lumefantrine (Coartem®) for malaria at PEC, unless contraindicated. Presumptive malaria treatment is documented on each refugee’s PDMS forms.

References

  1. Minnesota Department of Health. Domestic Medical Screening Data, 1999–2016 (unpublished data). 2017.
  2. Yun K, Matheson J, Payton C, et al. Health profiles of newly arrived refugee children in the United States, 2006–2012. Am J Public Health 2016 Jan;106(1):128–35.
  3. World Health Organization. Tuberculosis country profiles. 2016; Available from: http://www.who.int/tb/country/data/profiles/en/External.
  4. Citrin D, Somali Tuberculosis Cultural Profile. 2006.
  5. Posey DL, Blackburn BGExternalWeinberg MExternal, et al. High prevalence and presumptive treatment of schistosomiasis and strongyloidiasis among African refugees. Clin Infect Dis 2007 Nov 15;45(10):1310-5.
  6. Summer AP, Stauffer W, Maroushek SR, Nevins TE. Hematuria in children due to schistosomiasis in a nonendemic setting. Clin Pediatr (Phila), 2006 Mar;45(2):177–81.