Community Based Parasitic Screening and Treatment of Sudanese Refugees: Application and Assessment of Centers for Disease Control Guidelines

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1 Am. J. Trop. Med. Hyg., 80(3), 2009, pp Copyright 2009 by The American Society of Tropical Medicine and Hygiene Community Based Parasitic Screening and Treatment of Sudanese Refugees: Application and Assessment of Centers for Disease Control Guidelines Stephanie K. Brodine, Anne Thomas, Robert Huang, Judith Harbertson, Sanjay Mehta, John Leake, Thomas Nutman, Kathleen Moser, Jamie Wolf, Roshan Ramanathan, Peter Burbelo, John Nou, Patricia Wilkins, and Sharon L. Reed * San Diego State University Graduate School of Public Health, San Diego, California; Departments of Medicine and Pathology, University of California, San Diego School of Medicine, San Diego, California; Laboratory of Parasitic Diseases and Laboratory of Sensory Biology, National Institutes of Health, Bethesda, Maryland; Tuberculosis Control and Refugee Health Services Branch, County of San Diego Health and Human Services Agency, San Diego, California; Division of Parasitic Diseases, Centers for Disease Control, Atlanta, Georgia Abstract. Centers for Disease Control guidelines for schistosomiasis and strongyloidiasis in Sudanese and Somali refugees are not widely implemented. Given limited prevalence data, we conducted a seroprevalence study of schistosomiasis, strongyloidiasis, and loiasis in Sudanese refugees across diverse ages. Sudanese refugees, ages 4 78, were recruited via community organizations. Half of the patients (86/172), were seropositive for schistosomiasis (46/171; 26.9%), strongyloidiasis (56/172; 33%), or both (16/171; 9.4%). No Loa loa infections were detected. Infection rates were similar in adults and children except that no schistosomiasis was detected in children < 4 years of age at the time of immigration to the United States. The high prevalence of schistosomiasis and strongyloidiasis in a community-based sample of Sudanese confirms the urgency for compliance with CDC refugee health guidelines. We detected no co-infection with Loa loa using the most sensitive serologic techniques, allowing use of ivermectin, the most effective treatment of strongyloidiasis. INTRODUCTION The United States receives more refugees for resettlement than most western nations, with over 43,000 entering the country in In 2006, 12,205 refugees arrived from the sub- Saharan Africa countries of Somalia and Sudan, a 24% increase from Sudan, especially the southern provinces including Darfur, has been embroiled in civil war for a number of years. Many have been displaced and become refugees dispersed throughout the region. The Lost Boys and Girls, a group of young orphans who traveled hundreds of miles by foot, represent only a small, though well-publicized part of this displaced population. Many Sudanese refugees have spent years in camps in Ethiopia, Kenya, and Egypt. Although these refugees have been resettled throughout the United States, some areas have received more than others. Providers and refugee health programs in these areas are now engaged in assessing these immigrants for diseases not commonly encountered in the United States. The Centers for Disease Control guidelines providing recommendations on health assessments, care, and treatment of the resettled Sudanese populations were first released in January of 2005, 2 amended in June 2005, 3 and recently updated in to be more inclusive. The initial guidelines were based on a serosurvey of the Lost Boys and Girls, which documented a high prevalence of these parasitic infections in this population: 44% tested positive for schistosomiasis and 46% for strongyloidiasis. 5 Presumptive treatment of schistosomiasis and Strongyloides was recommended, with two doses of praziquantel (20 mg/kg in two doses) in refugees ³ 4 years of age and albendazole 400 mg twice a day for 7 days, 3 respectively. Contraindications included pregnant or breastfeeding women or those at risk for cysticercosis. Despite these findings and the presence of guidelines, few U.S. communities have implemented/initiated these guidelines and pre-departure therapy for schistosomiasis and strongyloidiasis is also limited. 6 This is likely because of a lack of experience * Address correspondence to Sharon L. Reed, UCSD Medical Center, 200 W. Arbor Drive, San Diego, CA slreed@ucsd.edu 425 in treating these conditions and limited resources for refugee specific services. Although the recently arriving Sudanese population differs from the original Lost Boys and Girls, who spent many months traveling on foot in southern Sudan, Ethiopia, and Kenya, they do originate from areas that are highly endemic for these parasitic diseases. Data on the seroprevalence of schistosomiasis and strongyloidiasis in this broader Sudanese population resettling in the United States is lacking. Although ivermectin is a more effective therapy for strongyloidiasis than albendazole, 7 a number of individuals developed encephalopathy attributed to co-infection with Loa loa during the control programs for onchocerciasis in Cameroon and neighboring countries. 8 Based on the potential risk of coinfection with Loa loa, a 7-day course of albendazole was recommended for the empiric treatment of strongyloidiasis in resettled Sudanese. 5 However, the prevalence of loiasis in the southern Sudan is unknown. Moreover, strongyloidiasis is the chronic parasitic infection associated with the highest postresettlement hospitalization costs and mortality. 9 Because of the lower efficacy of albendazole, additional data to guide treatment is important. Accordingly, we conducted a cross-sectional study of seroprevalence rates of schistosomiasis, strongyloidiasis, and loiasis in Sudanese resettled in San Diego who were 4 years of age and older. MATERIALS AND METHODS Design and study population. We designed a cross-sectional seroprevalence study of Sudanese refugees ³ 4 years of age who were born prior to their resettlement in San Diego. All participants in the study qualified at entry to the United States to receive California State refugee services. All refugees had received a screening examination on arrival in the United States including a complete blood count, TB skin testing, stool exams for ova and parasites, and serologies for hepatitis B in persons > 3 years of age. Human immunodeficiency virus (HIV) screening is done before departure. A multi-lingual Sudanese outreach worker facilitated study recruitment, collaborating with partnering agencies (e.g., International Rescue Committee, Catholic Charities), community-based institutions

2 426 BRODINE AND OTHERS (churches, community centers), and local Sudanese opinion leaders. Temporary study sites were set up for each clinic/ data collection event in convenient locations, and transportation was provided. Participants were consented following educational sessions on schistosomiasis, strongyloidiasis, and loiasis using pictorial materials developed for the project. An interview was conducted, which included date of entry into the United States, place of birth, and geographic migration. A medical history, physical examination, and blood draw were performed at the initial visit. The protocol was approved at the institutional review boards (IRB) of the Graduate School of Public Health, San Diego State University and the University of California San Diego, School of Medicine. Laboratory screening. Specimens were obtained for a complete blood count, smear for Loa loa, and serologies for schistosomiasis, strongyloidiasis, and loiasis. The peripheral blood smear (ideally drawn in day time) was screened microscopically for Loa loa before ivermectin was given following the initial clinic visit. The Loa loa and Strongyloides serologies were performed at the Laboratory of Parasitic Diseases, National Institutes of Health (NIH). The IgG4 antibodies reacting to a recombinant Loa loa antigen, Ll-SXP-1, were determined using a recently described luciferase immunoprecipitation system (LIPS) assay. 10 The Strongyloides serologies were determined by enzyme-linked immunosorbent assay (ELISA) using a L3-stage larval immunodiagnostic antigen, NIE. 11 Schistosomal serologies were performed at the CDC ( N = 147) by immunoblot to S. mansoni and S. haematobium ELISA microsomal antigens 12 and at ARUP Laboratories, (Salt Lake City, UT) ( N = 24) by ELISA to soluble egg antigens without speciation. Treatment and follow-up. At the initial clinic visit, all pa tients who met the criteria (³ 4 years of age, no history of seizures, not pregnant or breast feeding) were provided treatment of schistosomiasis with praziquantel (20 mg/kg in two doses 6 8 hours apart). 3 Following confirmation of a negative peripheral smear for Loa loa, treatment of Strongyloides (ivermectin 200 mcg/kg in one dose, the recommendation at the time) was given at a follow-up visit to a Public Health Clinic or delivered to patients. No information on pre- departure treatment was available. All children between the ages of 4 and 17 were also given a single dose of albendazole (400 mg) or mebendazole (500 mg) to treat other intestinal parasites. When blood could not be obtained for screening, albendazole was given (400 mg twice a day for adults or 15 mg/kg/day divided every 12 hours for children for a total of 7 days) to treat both Strongyloides and other parasites. Pregnant women were treated following delivery, and two patients with a history of a seizure disorder were treated only after confirmed serologic results. Letters detailing the treatment provided and the CDC recommendations were sent to the physicians of patients with established medical care. time of entry. The majority (64%) had emigrated from Egypt, followed by Kenya (31%) with years of immigration ranging from 1991 to 2007; 54% arrived in San Diego between 2002 and 2006, which represents 36% of the 259 Sudanese resettled in San Diego during this same period. Twenty-eight percent had no health insurance and 38% reported not having a regular physician (Table 1). Overall, self-reported health was good to excellent in 66%, although chronic abdominal pain was commonly reported (26%). An abnormal abdominal examination was found in 17%. Mean hemoglobin was 13.8 and 13% of patients had eosinophil counts > 450/mm 3. Of 171 samples tested for schistosomiasis, 46 (27%) were positive. Of the 147 speciated samples, 19 (13%) were infected with S. hematobium and 29 (20%) with S. mansoni. Fifty-six (33%) of individuals were seropositive for strongyloidiasis. None of the 170 peripheral smears examined demonstrated Loa loa microfiliariae. Thirty-seven (22%) tested positive for filiarial IgG4, however, all of these samples were negative by Loa loa SXP-1 based LIPS (Table 2). 10 There were no schistosomiasis infections in children < 4 years of age at the time of immigration ( Figure 1 ). In contrast there was no association with age in strongyloidiais prevalence rates. Gender, country of departure, year of immigration, history of chronic abdominal pain, abnormal abdominal exam, and presence of eosinophilia were not predictive of infection with either schistosomiasis or strongyloidiasis (Table 1). Ultimately, 171 patients were treated with praziquantel, 164 with ivermectin, and 6 with albendazole (for 7 days). Thirty-six children received single dose albendazole and 25 mebendazole. Pregnant or breastfeeding women ( N = 6) were subsequently treated only for seropositive results. Three were seronegative, one received praziquantel, and two ivermectin. No patients reported adverse reactions to the medications. DISCUSSION In contrast to previous studies, 5 our seroprevalence study of resettled Sudanese refugees included a broad age range, from 4 to 78 years of age, with nearly as many females as males. We found a similarly high prevalence of strongyloidiasis and/ or schistosomiasis: 50% in this Sudanese refugee population had one or both of these infections. Interestingly, children from this group who were < 17 years of age and had not traveled extensively on foot, as had the Lost Boys and Girls, also had comparably high rates of parasitic infection: 45% with either strongyloidiasis, schistosomiasis, or both. There was no RESULTS Between October 2006 and June 2007, 181 Sudanese were screened for study enrollment at four different community sites, with complete survey and serologic data available in 172. Reasons for exclusion included young age ( N = 2), birth in the United States ( N = 1); or inability to obtain a blood sample ( N = 6). Fifty-four percent were male, with a mean age of 27.3 years and 63 (37%) were under the age of 18 at the F IGURE 1. Schistosomiasis and strongyloidiasis infection by age at entry to the United States among 172 Sudanese refugees.

3 COMMUNITY BASED PARASITIC SCREENING OF SUDANESE REFUGEES 427 evidence of schistosomiasis infection in children who were 3 years of age or less at the time of resettlement, which is consistent with a lower likelihood of exposure of infants to fresh water rivers and lakes. One-third of our patients were seropositive for Strongyloides. This is particularly important as Strongyloides is unusual among intestinal helminths in its capacity for autoinoculation and therefore survival within the host for decades without reinfection from an exogenous source. 13 Thus, as hosts age and particularly if they are immunosuppressed medically (e.g., corticosteroids) or a consequence of conditions such as HIV, 14 the possibility of disseminated Strongyloides and hyperinfection syndrome increases. Disseminated Strongyloides and the hyperinfection syndrome has been associated with a mortality rate of up to 70%, 15 despite appropriate treatment of Strongyloides and the gram negative enteric bacteremia, which often accompanies it. Thus, in populations already known to have a high incidence of Strongyloides, the cost and health benefits of empiric treatment to prevent these catastrophic outcomes is likely to outweigh potential barriers such as drug cost and toxicity. Studies by Muennig and others 16 showed that presumptive therapy of Strongyloides with ivermectin was cost-effective when the prevalence was 2%, which is substantially lower than was found in this and the CDC study. 5 We found that 20% of our patients were seropositive for S. mansoni and 13% for S. hematobium. Schistosomiasis encompasses a range of disease manifestations from acute Katayama fever to fibrosis of the liver ( S. mansoni ) and bladder/urinary tract ( S. hematobium ) that lead to hepatomegaly resulting 17, 18 from portal hypertension and bladder cancer, respectively. These chronic manifestations of schistosomiasis are often the result of reinfection from continuous exposure in endemic areas and of high trematode and egg burdens. It was previously believed that once some of the pathologic findings had occurred in schistosomiasis, treatment would not positively impact disease progression; however, further work has shown that treatment even in more advanced stages of disease is still of benefit. Treatment is unquestionably helpful early in the disease course. 19 Given the broad age range of patients with positive schistosomal serologies in our cohort, our seropositive patients were likely to be in various stages of disease progression and would have all benefited to some degree from the praziquantel received. 6 Although praziquantel is contraindicated in children less than 4 years of age, none of the study participant children in this age group at entry were seropositive for schistosomiasis, suggesting that there may be no need for a return visit for empiric praziquantel in children 4 years or younger at the time of immigration. The direct detection of parasites in stool or blood on a single screening examination is relatively insensitive. It is estimated that a single stool exam would only identify 30 50% of patients actually infected with Strongyloides, 20 and an estimated 50% of patients with schistosomal infection may be missed. 21 Loa loa microfilariae is best detected in a midday blood smear, but as many as 80% of short-term infected visitors and 20% of people living in endemic areas do not have 22, 23 detectable parasites in their blood. The development of species-specific (and non-cross reactive) serologic tests for helminths has been especially challenging. The use of recombinant antigens has significantly improved the reproducibility of assays. This approach has proved useful in the diagnosis of Strongyloides as earlier assays required the extraction of antigens from larvae. The physiologic relevance of the recombinant antigen used in this assay, NIE, was supported by its ability to release histamine in Strongyloides -infected patients, and had a sensitivity of 87.5%. 24 The potential to over-estimate active disease exists, however, as seropositivity may persist. This overestimation is less likely with strongyloidiasis as follow-up of patients in non-endemic areas with positive stool exams after successful treatment found that more than 90% of patients had a significant decline in their serologic response. 25 Therefore, seropositivity for Strongyloides (in the absence of treatment) is more likely to reflect active infection. Additional serologic testing to confirm effective therapy would have been useful, but was beyond the scope of our project. We did inform all primary care physicians of our findings and the need for follow-up, particularly the one HIV+ patient. The highest prevalence of strongyloidiasis was in the year age group at entry (47%). Studies from the Amazon found seroprevalence for Strongyloides continued to increase with age, but they were following a population still living in an endemic area. 26 The utility of serology in the specific diagnosis of schistosomiasis has also increased with the use of species-specific microsomal antigens in an ELISA or immunoblot. We found an overall seropositive rate of 27%, which is closer to that of the Somali Bantu (23%) in Posey s recent serosurvey 5 than to the Lost Boys and Girls (44%) and may reflect the diverse ages in the populations studied. In the 39 patients in whom we had species-specific information, 29 were infected with S. mansoni, 19 with S. hematobium, and 9 with both. Ours is the first study to evaluate loiasis in a large number of Sudanese refugees. We chose to first screen the peripheral blood of patients for Loa loa before treating with ivermectin in that this method should detect 50 (or greater) microfilaria/ ml of blood, whereas the cases of encephalopathy after ivermectin therapy typically had greater than 10,000 microfilariae/ ml 8. Similar negative results were found in a smaller group of Lost Boys recently reported by Franco-Paredes and others. 27 We initially tested for anti-filarial IgG4 and found a similar positive rate of 21%, which they attributed to onchocerciais. Although we did not perform skin snips to rule out onchocerciasis, none of our patients reported pruritus before or after therapy, suggesting the positive serology may reflect longstanding, inactive filarial infection (or merely exposure to the infective stage larvae). Because the clinics were entirely run by volunteers after hours, not all blood for Loa loa were drawn during the day, which might have decreased the detection of microfilaria. However, the timing of the blood draw would not affect serologies for Loa loa using a very specific LIPS assay using recombinant Ll-SXP-1 antigen fused to renilla luciferase. 10 This assay was determined to be between % sensitive and 100% specific. 10 The complete absence of detectable Loa loa in our population was somewhat of a surprise, although this may be consistent with the self-limited life span of the adult worm and the location of the refugee camps. The risk of encephalitis in patients infected with Loa loa and treated with ivermectin is dependent on the microfilarial burden; thus, a negative blood film significantly reduces this risk. Ivermectin is known to be a more efficacious treatment of Strongyloides than is albendazole, with cure rates of 85% for the former versus 45% for the latter. 7 In addition to improved efficacy, single-dose

4 428 BRODINE AND OTHERS T ABLE 1 Demographic and clinical characteristics by schistosomiasis and strongyloidiasis serologies in 172 San Diego County resettled Sudanese refugees, Schistosomiasis (N = 171) Strongyloidiasis ( N = 172) Total ( N = 172) Yes ( N = 46) No ( N = 125) Yes (N = 56) No ( N = 116) n % n % n % P value n % n % Age years 30/170 (17.7) 4/46 (8.7) 26/123 (21.1) /55 (20.0) 19/115 (16.5) years 23/170 (13.5) 4/46 (8.7) 19/123 (15.5) 3/55 (5.5) 20/115 (17.4) ³ 18 years 117/170 (68.8) 38/46 (82.6) 78/123 (63.4) 41/55 (74.6) 76/115 (66.1) Age at entry to US 1 month 3 years 14/172 (8.1) 0/46 (0.0) 14/125 (11.2) 0.06* 5/56 (8.9) 9/116 (7.8) years 34/172 (19.8) 8/46 (17.4) 26/125 (20.8) 8/56 (14.3) 26/116 (22.4) years 15/172 (8.7) 5/46 (10.9) 10/125 (8.0) 7/56 (12.5) 8/116 (6.9) ³ 18 years 109/172 (63.4) 33/46 (71.7) 75/125 (60.0) 36/56 (64.3) 73/116 (62.9) Sex Male 93/172 (54.1) 27/46 (58.7) 65/125 (52.0) /56 (42.9) 55/116 (47.4) 0.57 Female 79/172 (45.9) 19/46 (41.3) 60/125 (48.0) 32/56 (57.1) 61/116 (52.6) Sudan birth location 2 Southern 104/153 (68.0) 34/42 (81.0) 69/110 (62.7) /49 (69.4) 70/104 (67.3) 0.80 Other 49/153 (32.0) 8/42 (19.1) 41/110 (37.3) 15/49 (30.6) 34/104 (32.7) Areas last lived 3 Egypt 104/163 (63.8) 25/43 (58.1) 78/119 (65.6) /52 (71.2) 67/111 (60.4) 0.35 Kenya 50/163 (30.7) 14/43 (32.6) 36/119 (30.3) 12/52 (23.1) 38/111 (34.2) Other 9/163 (5.5) 4/43 (9.3) 5/119 (4.2) 3/52 (5.8) 6/111 (5.4) Self-reported chronic abdominal pain 4 Yes 42/161 (26.1) 13/42 (31.0) 29/118 (24.6) /51 (21.6) 31/110 (28.2) 0.37 No 119/161 (73.9) 29/42 (69.1) 89/118 (75.4) 40/51 (78.4) 79/110 (71.8) Abnormal abdominal exam 5 Yes 29/167 (17.4) 10/45 (22.2) 19/121 (15.7) /55 (16.4) 20/112 (17.9) 0.81 No 138/167 (82.6) 35/45 (77.8) 102/121 (84.3) 46/55 (83.6) 92/112 (82.1) Total eosinophilia count > Yes 22/168 (13.1) 9/45 (20.0) 13/122 (10.7) /56 (16.1) 13/112 (11.6) 0.42 No 146/168 (86.9) 36/45 (80.0) 109/122 (89.3) 47/56 (83.9) 99/112 (88.4) * Fisher s Exact Test: 1 Age (age at interview); missing = 2. 2 Birth location; missing = 9; missing = 10 from another country/not Sudan. 3 Area last lived; missing = 9. 4 Chronic Ab pain; missing = Ab exam; missing = 5; only 4 participants with an abnormal abdominal exam had mild hepatomegaly or splenomegaly. 6 Eosinophilia > 450; missing = 4. P value ivermectin will result in better compliance than a 7-day course of albendazole and is less expensive (US$16 for treatment of a 60 kg patient with ivermectin versus US$35 for albendazole). Subsequent to our clinics, a 2-day course of ivermectin has been recommended. 5 Serious adverse events, which occurred in Africa with mass treatment using ivermectin were virtually all reported from southern Cameroon, where there are higher rates of co-infection with Loa loa ; however, this higher prevalence only partially appears to explain the higher rates of complications. 28 Therefore, care must be taken to remain vigilant about the possibility of adverse outcomes with routine ivermectin or albendazole administration. A history of living in a known Loa - or Taenia -endemic area should be obtained from any possible recipients of either of these drugs. Because no loiasis was found in our patients and no symptoms were reported in the 164 patients we treated with ivermectin, we suggest that in the southern Sudanese refugee population, ivermectin should be considered as first line therapy for the empiric treatment of strongyloidiasis in the United States. A negative screening day blood film in any patient with a potential exposure to Loa loa should reduce the risk of encephalopathy from filarial death and inflammation to a truly negligible level. Only 13% of our subjects had evidence of eosinophilia, as defined by a total eosinophil count of > 450/mm. 3, 29 There was a trend toward a higher percentage of eosinophilia in multiply infected patients than the uninfected, but no difference compared with either the Strongyloides or schistosomiaisis mono-infected groups, which were also similar to each other. Previous studies of refugee populations have found rates of eosinophilia of at least 12%, 30, 31 similar to our findings. Our data also support previous studies demonstrating that eosinophilia is not an adequate biomarker 6, 29, 31 as we would have detected only 20% of the schistosomiasis seropositive and 16% of the Strongyloides seropositive patients (Table 1 ). In addition, we saw no significant difference in symptoms or physical exams between subjects with and without Strongyloides or schistosomiasis. This last finding particularly underscores the importance of empiric therapy in populations at high risk for these infections even when asymptomatic as proposed in CDC recommendations. 3, 5 The challenges in providing refugee health screening and care can be substantial and include language barriers, cultural differences in health perception, lack of established trust, transportation, and insufficient funding. Failure to acknowledge and address these issues may contribute to suboptimal health care for refugee populations. We found this Sudanese refugee population in San Diego to be largely receptive to the screening and treatment of their parasitic infections. An integral part of the success of our program was the active involvement of leaders in the refugee community in advertising the clinic s purpose, organizing transportation, and being the ready liaison between the health care team leaders and the community. The graphics-based health education materials we produced were used to explain the goals and procedures involved in the clinic and treatment. The volunteer clinic staffing response was even

5 COMMUNITY BASED PARASITIC SCREENING OF SUDANESE REFUGEES 429 T ABLE 2 Clinical and parasitic serologic findings in 172 San Diego Country resettled Sudanese refugees, n (%) Clinical History Self-reported chronic abdominal pain, n/n (%)* 42/161 (26.1) Laboratory Total white blood cell count, mean ± SD (range) 6.2 ± 1.97 ( ) Hemoglobin, mean ± SD (range) 13.8 ± 1.72 ( ) Total eosinophilia count > 450, n/n (%) 22/168 (13.1) Serologies Strongyloides positive serology, n/n (%) 56/172 (32.6) Schistosomiasis positive serology, n/n (%) 46/171 (26.9) Schistosoma haematobium positive serology 19/147 (12.9) Schistosoma mansoni positive serology 29/147 (19.7) Positive for both infections, n/n (%) 16/171 (9.4) Positive for either infection, n/n (%) 86/172 (50.0) Loa loa Laboratory Results, n/n (%) Loa loa positive smear result 0/170 (0.0) Positive SXP 0/37 (0.0) * N = 11 missing data on chronic abdominal pain. N = 1, missing white blood cell (WBC) and hemoglobin (HGB). N = 4, missing eosinophilia. N = 1 not tested for schistosomiasis, but have Strongyloidiasis results. N = 24 missing species-specific serology for schistosomiasis; 9 positive for both species. greater than anticipated from all of the participating institutions, suggesting a great, multidisciplinary untapped human resource for public health initiatives. These clinics also served an important function in informing and sensitizing health care professionals and students to the presence and challenges of African refugees that have resettled in the United States. In reviewing our results, it is clear that there continues to be a need for additional data on the prevalence, ideal screening methods, and empiric treatment of parasitic diseases among African refugees, particularly the children. Efforts to give presumptive treatment of schistosomiasis with praziquantel and albendazole for other helminths before resettlement have been shown to be effective 32 and are emphasized in the 2008 CDC Predeparture Refugee Health Guidelines. 4 Our findings, with a broader population including females and a wider age range, support the importance of presumptive therapy in Sudanese refugee populations. 5, 32 As shown in other studies, neither abdominal pain nor eosinophilia is predictive of infection with Strongyloides or schistosomiasis. 6, 29, 31 We found that none of our patients had Loa loa infection, allowing safe and effective treatment with ivermectin in Sudanese refugees. Received September 17, Accepted for publication November 26, Acknowledgments: We thank Molly and Becky Moores for their dedication to the Sudanese refugees, all of the participating families, and the many volunteers who made this study possible. The high participation rate of the Sudanese community would not have been possible without the outreach and guidance of Diar Diar, Majur Malou, and Dep Tuany. We also thank Marianna Wilson of the CDC for her help and encouragement. Financial support: Funding for the study was provided by the John and Rebecca Moores Foundation for New Americans and in part by the Division of Intramural Research, NIAID. Disclosure: The authors report that there are no conflicts of interest. Authors addresses: Stephanie Brodine, Anne Thomas, Judith Harbertson, and Jamie Wolf, Graduate School of Public Health MC 4162, San Diego State University, 5500 Campanile Drive, San Diego, CA Robert Huang, Sanjay Mehta, and Sharon Reed, UCSD Medical Center, 200 W. Arbor Dr., San Diego, CA , Tel: , Fax: , slreed@ucsd.edu. John Leake, Division of Infectious Diseases, Rady Children s Hospital, 3020 Children s Way, MC5041, San Diego, CA Thomas Nutman and Roshan Ramanathan, Laboratory of Parasitic Diseases, Bldg 4, Rm B1-3, 4 Center Dr., National Institutes of Health, Bethesda, MD Kathleen Moser, Tuberculosis Control and Refugee Health Services Branch County of San Diego Health and Human Services Agency, 3851 Rosecrans St., MS P576, Suite 128, San Diego, CA Peter Burbelo, Laboratory of Sensory Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD John Nou and Patricia Wilkins, Reference Diagnostic Laboratory, Division of Parasitic Diseases, Centers for Disease Control, Atlanta, GA REFERENCES 1. United States Department of Homeland Security, Yearbook of Immigration Statistics : Washington, D.C: Office of Immigration Statistics. 2. 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