Parasitic Disease Surveillance, Mississippi, USA

Richard S. Bradbury; Meredith Lane; Irene Arguello; Sukwan Handali; Gretchen Cooley; Nils Pilotte; John M. Williams; Sam Jameson; Susan P. Montgomery; Kathryn Hellmann; Michelle Tharp; Lisa Haynie; Regina Galloway; Bruce Brackin; Brian Kirmse; Lisa Stempak; Paul Byers; Steven Williams; Fazlay Faruque; Charlotte V. Hobbs

Disclosures

Emerging Infectious Diseases. 2021;27(8):2201-2204. 

In This Article

Conclusions

The results of this limited pilot study suggest a low prevalence of STH infections in Mississippi but that rare infections with S. stercoralis might be found in Mississippi residents. The single case confirmed by real-time PCR tests likely represents active infection. Because >80% of patients with strongyloidiasis serorevert within 18 months after successful treatment,[7] the 4 confirmed antibody-positive serum samples also likely represent active cases of strongyloidiasis. No linked immigration or travel history data on patients providing these samples were available, so whether these infections were acquired within the United States is unknown. Combined with the recent finding of strongyloidiasis in a rural community from Alabama,[3] these data should encourage more focused sampling of areas with poor sanitation and hygiene, high levels of poverty, and poor access to healthcare for potential residual foci of endemic STH and strongyloidiasis transmission in Mississippi and the wider southeastern United States.

The total Toxocara spp. seroprevalence in all participants in this study was 8.8%, which is higher than the average prevalence reported by the most recent National Health and Nutrition Examination Survey study.[8] Although these results are not directly comparable because of different sampling methods, the potentially high Toxocara spp. seroprevalence in Mississippi warrants further investigation.

The seroprevalence results of this study suggest that prior exposure to Cryptosporidium spp. is common in Mississippi. Only 5.7% of the postdiagnostic serum samples were found to have serologic evidence of prior exposure to G. duodenalis infection. A small number of samples (1.9%) contained antibodies reacting with the 3 antigens Cp17, Cp23, and VSP3, indicating prior exposure to Cryptosporidium spp. and G. duodenalis infection. Further investigation of the epidemiology of waterborne protozoan infection in Mississippi, including determination of the actual prevalence and distribution using systematic sampling and determination of the species and subtypes infecting persons, is warranted.

The absence of any positive findings by microscopic examination or PCR for the STH suggests that such infections are uncommon in the general Mississippi population. We found high seroprevalence of antibodies to Toxocara spp. in Mississippi. Although this finding could indicate increased exposure to this infectious agent compared with the national average, our data do not enable determination of the sources of increased infection or overall annual incidence of disease. Further studies on the epidemiology and prevalence of parasitic diseases in the state of Mississippi are indicated.

In conclusion, this convenience sampling study did not find evidence of high STH prevalence in Mississippi. However, we did identify several likely current cases of strongyloidiasis and relatively high rates of Toxocara exposure. We recommend further investigation with larger sample sizes to more clearly define the true extent of STH infection in this region.

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