Strongyloidiasis is a human parasitic disease caused by the nematode called Strongyloides stercoralis, or sometimes the closely related S. fülleborni.

In some people, particularly those who require corticosteroids or other immunosuppressive medication, Strongyloides can cause a hyperinfection syndrome that can lead to death if untreated.

[citation needed] Dissemination can occur many decades after the initial infection[9] and has been associated with high dose corticosteroids, organ transplant, any other instances and causes of immunosuppression, HIV,[10][11] lepromatous leprosy, tertiary syphilis, aplastic anemia, malnutrition, advanced tuberculosis and radiation poisoning.

The reality of global travel and the need for modern advanced healthcare, even in the so-called "developed world", necessitates that in non-endemic areas there is easily accessible testing and screening for neglected tropical diseases such as strongyloidiasis.

[citation needed] Escalated disseminated infections caused by immunosuppression can result in a wide variety and variable degree of disparate symptoms depending on the condition and other biological aspects of the individual, that may emulate other diseases or diagnoses.

In addition to the many palpable gastrointestinal and varied other symptoms drastic cachexia amidst lassitude is often present, although severe disseminated infections can occur in individuals without weight loss regardless of body mass index.

[citation needed] Diagnosis rests on the microscopic identification of larvae (rhabditiform and occasionally filariform) in the stool or duodenal fluid.

[16] Serology can cross-react with other parasites, remain positive for years after successful treatment or be falsely negative in immunocompromised patients.

[citation needed] It would be useful to have significant advances in the sensitivity of the means of diagnosis, as it would also solve the challenging problem of proof of cure.

There is an auto-infective cycle of roughly two weeks during which ivermectin should be re-administered; however, additional dosing may still be necessary as it will not kill Strongyloides in the blood or larvae deep within the bowels or diverticula.

As cited earlier, since some infections are insidiously asymptomatic, and relatively expensive bloodwork is often inconclusive via false-positives or false-negatives,[23] just as stool samples can be unreliable in diagnoses,[24] there is yet, unfortunately, no real gold standard for proof of cure, mirroring the lack of an efficient and reliable methodology of diagnosis.

[4][19][25] An objective eradication standard for strongyloidiasis is elusive given the high degree of suspicion needed to even begin treatment, the sometimes difficulty of the only definitive diagnostic criteria of detecting and isolating larvae or adult Strongyloides, the importance of early diagnosis, particularly before steroid treatments,[26] and the very wide variability and exclusion/inclusion of differing collections of diffuse symptoms.

[32] Furthermore, progress is required in establishing financial support to facilitate and cover affordable medications for individuals in affected at-risk regions and communities to help continue treatments.

[37] Major inroads are required to advance the development of successful medications and drug protocols for strongyloidiasis and other neglected tropical diseases.

It has been shown possible to occur in that situation, or potentially other similar scenarios, it is speculated via pulmonary secretions of a direly hyperinfected individual.

In which case treatment for others may be indicated, if deemed necessary by proximity, symptoms, precautions, probable exposures to the same vectors, or through screening of serology and stool samples, until infection is eradicated.

Thus extreme caution with respect to iatrogenic risks is crucial to avoiding deaths or other adverse consequences in treatment, that of course prefigures a correct diagnosis.

[42][43] People with high exposure to Strongyloides stercoralis may mitigate the risk of strongyloidiasis hyperinfection associated with corticosteroid treatment, with the presumptive use of ivermectin.

[3] The disease was first recognized in 1876 by the French physician Louis Alexis Normand, working in the naval hospital in Toulon; he identified the adult worms and sent them to Arthur René Jean Baptiste Bavay, affiliated with France's Superior Council on Health, who observed that these were the adult forms of the larvae found in the stool.