Intestinal parasitic infection among new refugees to Minnesota, 1996–2001

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Abstract

Objectives

The primary objective of this study was to evaluate the prevalence of pathogenic intestinal parasitic infection in primary refugees to Minnesota (MN). Secondary objectives were to determine the association of intestinal parasitic infection with gender, age and continent of origin.

Methods

A retrospective study was conducted on the first refugee screening visits done between January 1, 1996 and December 31, 2001 on data from the Minnesota Department of Health.

Results

Of the 10,358 refugees with screening results, 1969 (19%) had pathogenic intestinal parasites. Parasites were more common in men (OR=1.3; p<0.0001) and were less prevalent with increasing 10 year age intervals (OR=0.79; p<0.001). Asians had the highest proportion of refugees with intestinal parasitic infection (33.6%; p<0.0001). The most common pathogenic intestinal parasites were Trichuris trichiura (7.1%), Giardia lamblia (5.7%), Ascaris lumbricoides (2.1%), and hookworm (2.0%).

Conclusion

In this study almost 20% of newly arrived refugees to the state of MN had evidence of intestinal parasitic infection. With very little organized access to health care following arrival of refugees to a new country, risk of transmission of infection, and persistence of infection, the first health visit should be used as a critical opportunity for the screening and treatment of high-risk patients. Future public health work should focus on enhanced screening and surveillance strategies, follow-up for ensuring adequate treatment completion and eradication of parasitosis, as well as research on cost effectiveness of screening versus predeparture anti-helminthic treatment.

Introduction

Refugees form a small albeit important fraction of the immigrants to the United States (US). Over 75,000 refugees resettled in Minnesota (MN) between 1979 and 20041 significantly influencing the epidemiology of infectious disease in the state. Intestinal parasitic infection affects about 14–50% of refugees to the US.2, 3, 4, 5 Refugees have a significantly higher risk of intestinal parasitic infection than the general US population6 or immigrants to the US.7 Most refugees to MN come from areas of high prevalence of intestinal parasitic infection and many endure poor living conditions in refugee camps, including inadequate housing, health care, nutrition, water, sanitation and education.

Parasitic infections can cause significant morbidity and can potentially lead to growth, nutrition and developmental impairment,8, 9, 10, 11 iron deficiency anemia due to hookworm,12 malabsorption of nutrients due to Giardia13 and obstruction of the intestine, pancreatic duct or bile duct due to Ascaris.14 However, very few refugees with parasitic infection are symptomatic4 and up to 22% of them continue to be infected with parasites years after migration to a new country.15, 16 In addition to its influence on individual and public health, knowledge about the epidemiology of parasitic infection is important in policy making and in the development of cost-effective screening programs for refugees. However, there is little published literature on the epidemiology of common diseases in the refugee population including intestinal parasitic infection on arrival to the US and the risk factors associated with infection.

The primary objective of this study was to evaluate the prevalence of pathogenic intestinal parasitic infection in primary refugee arrivals to MN. Secondary objectives were to determine the association of pathogenic parasitic infection with refugee gender, age, and continent of origin.

Section snippets

Materials and methods

Refugees are defined as persons outside their countries of origin because of a well-founded fear of persecution based on their race, religion, nationality, political opinion or membership in a particular social group, and who cannot or do not want to return home.17 For the purpose of this study, we have defined a primary refugee as one whose initial resettlement after arriving to the US is MN.

Mandatory pre-departure screening by clinicians working for the International Organization for

Results

Between 1996 and 2001, 16,239 primary refugees immigrated to MN.18 Of these, 15,949 (98.2%) refugees with submitted initial refugee health assessment forms constituted the study sample. The largest number (25%) of refugees arrived to MN in 2000. Most of the refugees were from Africa (62.1%), followed by Europe (28.3%), Asia (9.6%), and South and Central America (0.1%) (see Table 1). A large proportion (48.9%) of refugees in the study sample was in the 19–64 age group. Both genders were well

Discussion

Migration is escalating internationally. The number of refugees in the world rose from 1 million in the 1960s to 22 million in 1998 and recently leveled at 11.9 million in 2003.20 Migration leads to concerns, for the ones that move, and for the host communities. Providing adequate care to people with diverse backgrounds, cultures, and ethnicity about which doctors have insufficient information is increasingly becoming a challenge.

In this study, 19% of the new refugees to MN had evidence of

Conclusion

In this study almost one in five newly arrived refugees to the state of MN had evidence of intestinal parasitic infection, and only 70% of the eligible patients were treated for the same. It is likely that in other areas where there is a high influx of African and Asian refugees, the epidemiology of parasitic infection is similar. With very little organized access to health care following arrival of refugees to a new country, risk of transmission of infection, and persistence of infection, the

Acknowledgments

Ethical Approval: This study was declared exempt by the Mayo Clinic Institutional Review Board as the data was obtained from a public database

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