The Association of Eosinophilia With Indolent Strongyloides In A Diversified Patient Population
Davinder Kumar M.D., Pierre Gonsalves, M.D., Lin ping hung M.D., Wei-fun Sung M.D., Renuka shetty Das M.D.
Background: Strongyloides stercoralis is one of the most common parasitic organisms for infectious causes of secondary eosinophilia. Worldwide 30-60 million people are infected. In the US, the prevalence is very low except among residents of southeastern states and immigrants, who have been in endemic areas. There is very little reported information on the association of eosinophilia with indolent strongyloides in an urban immigrant outpatient population from endemic areas.
Objective: The objective of this observational study was to determine the association of eosinophilia with indolent strongyloides in a multiethnic outpatient clinic population followed at New York Hospital Queens.
Methods: We reviewed records of 36 consecutive patients who, from April 2008 to February 2009, had their strongyloides IgG levels drawn as part of a comprehensive evaluation for high percent eosinophiles (= or>5 %). The study population consisted of female (n=17) and male (n=18) patients, aged 24 to 81, from four broad geographic areas of origin (Asia =12, Europe=1, North America=3, and South America=20). Information on country of origin, age, gender, and laboratory data including serum strongyloides Elisa IgG, stool ova and parasite, complete blood count with eosinophilia was analyzed. The diagnosis of indolent strongyloides was made by detectable strongyloides IgG level or visualization of strongyloides larva on stool examination. Patents with positive tests were treated with 2 single doses of ivermetin at 200 mcg/kg, 2 weeks apart. Post treatment reduction in strongyloides IgG and eosinophil count was analyzed. SAS software was used for all statistical analysis.
Results: The study group consisted of 33 immigrants and 3 nonimmigrants. The mean age for the study population was 56.64 (SD =12.76.) The mean eosinophil count was 586.56 (SD =333.73). There were 13 seropositive cases of indolent strongyloides (IgG level range 95 to 1.15, mean =11.57, and SD = 25.18), and all stool studies were negative. The prevalence of indolent strongyloides is 39.39% (13/33) for the immigrant group, whereas it was 0 % (0/3) in the nonimmigrant group. The geographic distribution of indolent strongyloides was: Asia=3, Europe=1, and South America =9. 12 out of 13 cases of indolent strongyloides were treated. 8 cases had post treatment IgG levels performed and 7 of the 8 had no detectable levels (IgG<1). The post treatment eosinophiles were available for 8 patients (mean = 223.77, SD =117.13). The reduction in eosinophil count and strongyloides IgG levels with treatment was statistically significant ( p< 0.05).
Conclusions: The incidence of indolent strongyloides, diagnosed by serum ELISA. Strongyloides IgG, in an immigrant population with eosinophilia is 39.39%. Treatment with Ivermectin significantly reduces the strongyloides IgG level and eosinophil count. Further study is needed to determine appropriate treatment goals and follow-up of post-treatment, persistently seropositive patients.