**12. Conclusion**

Strongyloidiasis is an infection with a tendency to become chronic with an indolent course. However, in immunocompromised patients, especially those treated with corticosteroids, hyperinfection syndrome can compromise the prognosis of the patient. The mortality rates of hyperinfection are high, making *Strongyloides* infection an important global health problem. It is important to understand the biology and immunology of infection with *S. stercoralis* and the altered courses of infection that may occur when immune regulation is compromised. Clinicians who are aware of the possibility of hyperinfection are better equipped to diagnose, treat, or altogether prevent the fatal consequences of this lethal nematode.

### **13. Acknowledgments**

388 Current Topics in Tropical Medicine

cell numbers may be elevated. Although an increase in eosinophils frequently occurs during infection, studies have shown that an absence of eosinophilia does not exclude a diagnosis of strongyloidiasis (Krishnan et al., 2006). Diagnosis through imaging is usually possible. Chest radiographs of some patients have shown infiltrate consistent with Loeffler's syndrome. Methods such as bronchoalveolar lavage and sputum culture are used to diagnose disseminated strongyloidiasis (Williams et al., 1988, Yassin et al., 2010). Duodenal fluid aspiration and intestine biopsy or the use of Enterotest ® may be required to detect the

Early identification of the disease and anthelminthic treatment results in a better prognosis for strongyloidiasis and, in many cases, prevents a fatal infection (Basile et al., 2010). *S. stercoralis* is resistant to anthelmintic drugs, and the parasite has the capacity to replicate and

Thiabendazole, albendazole, and mebendazole are effective drugs against *S. stercoralis.* Thiabendazole was the drug of choice for treatment of strongyloidiasis, with a cure rate of up to 80%. Albendazole has variable therapeutic efficacy but has been used in hyperinfection syndrome and remains a viable treatment alternative to ivermectin. Mebendazole can be used to treat strongyloidiasis but is not recommended because of an association with liver dysfunction (Rajapurkar et al., 2007). Recently, there has been a change in the treatment of strongyloidiasis, as more studies support the choice of the drug ivermectin, which is effective at killing worms in the intestine. In patients with hyperinfection syndrome, ivermectin is considered the first-line therapy, and longer courses

Efficient treatment of strongyloidiasis depends on several factors that can decrease the efficacy of the drugs used for treatment, such as immunodeficiency, corticosteroid use, or co-infection with HTLV-1 (Vadlamudi et al., 2006). Prolonged or repeated treatment may be

Other measures, including decreasing the dosage of corticosteroids, discontinuing immunosuppressive therapies and treating bacterial infections, are essential elements in the treatment of these patients. In all cases, patients with strongyloidiasis, regardless of the severity

Like other soil-transmitted nematode infections, strongyloidiasis can be controlled by improving sanitary conditions and properly disposing of faeces. Infected patients should be treated, even if they are asymptomatic, to preclude the possible onset of autoinfection. Immunosuppressants are contraindicated in these patients. Personal hygienic measures like proper protection of the skin to prevent contact with infected soil, community education about protective and hygienic measures, and prompt treatment of diagnosed cases would

Strongyloidiasis is an infection with a tendency to become chronic with an indolent course. However, in immunocompromised patients, especially those treated with corticosteroids,

of symptoms, must be treated to prevent long-term complications (Montes et al., 2010).

*Strongyloides* parasite (Yassin et al., 2010).

increase the worm burden again (Grove, 1996).

of treatment are indicated (Roxby et al., 2009).

help prevent the disease (Vadlamudi et al., 2006).

required in patients receiving immunosuppressive drugs.

**10. Treatment** 

**11. Control** 

**12. Conclusion** 

We wish to thank Elaine Medeiros Floriano for excellent technical assistance and Mara R. Celes and Marcela S. Oliveira for photography assistance.

**Financial support:** This study was supported by the FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo) and CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico). Cristiane Tefé-Silva is supported by a scholarship through CNPq. Simone G. Ramos and Lúcia H. Faccioli are investigators at CNPq.
