Journal of The Academy of Clinical Microbiologists

: 2021  |  Volume : 23  |  Issue : 2  |  Page : 88--91

Strongyloides hyperinfection syndrome in a patient with COVID 19

Beena Philomina Jose, Shivapriya P Charu, Vishnu Kaniyarakkal 
 Department of Microbiology, Government Medical College, Kozhikode, Kerala, India

Correspondence Address:
Dr. Beena Philomina Jose
Department of Microbiology, Government Medical College, Kozhikode - 673 008, Kerala


The severe acute respiratory syndrome coronavirus 2 (SARS CoV 2) which started the corona virus disease 2019 (COVID 19) outbreak is an RNA virus commonly spread via respiratory droplets. The infection may remain asymptomatic or present with mild upper respiratory symptoms or take a severe form with pneumonia and severe acute respiratory distress syndrome (ARDS) that requires assisted ventilation and presents complications with negative outcome. Rate of co-infections and super-infections in hospitalised COVID 19 patients even though low when compared to other respiratory infections, may cause severe disease with worse outcome when present. Here we present a case of strongyloides hyperinfection syndrome complicating SARS CoV-2 infection possibly brought on by the use of immune altering therapy for COVID 19.

How to cite this article:
Jose BP, Charu SP, Kaniyarakkal V. Strongyloides hyperinfection syndrome in a patient with COVID 19.J Acad Clin Microbiol 2021;23:88-91

How to cite this URL:
Jose BP, Charu SP, Kaniyarakkal V. Strongyloides hyperinfection syndrome in a patient with COVID 19. J Acad Clin Microbiol [serial online] 2021 [cited 2022 Jul 5 ];23:88-91
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Full Text


The severe acute respiratory syndrome coronavirus 2 (SARS CoV 2) is responsible for the outbreak of coronavirus disease 2019 (COVID-19) which initially started in the Asian city of Wuhan and subsequently spread over the world. It is an enveloped, positive sense single stranded RNA virus of the Coronaviridae family.[1] SARS CoV-2 is thought to commonly spread through respiratory droplets formed while talking, coughing and sneezing of an infected individual[2] and uses a glycoprotein (spike protein) to bind to the angiotensin-converting enzyme 2 receptor of humans. Following the entry of virus, some infected individuals may remain asymptomatic or only present with mild upper respiratory symptoms, others develop pneumonia and severe acute respiratory distress syndrome (ARDS) that requires assisted ventilation and presents complications with negative outcome. Coinfections and super-infections in hospitalised COVID-19 patients are lower compared to that occurring in patients with other respiratory viral infections, such as influenza H1N1 or influenza H3N2. However, when present, coinfections and superinfections may cause severe disease with worse outcomes.[3],[4],[5],[6],[7]

Mortality is associated with advanced age, the presence of co-morbidities, greater disease severity, worsening of respiratory failure, high levels of D-Dimer and C-reactive protein, low lymphocyte counts and infections.[8] Various immunomodulators have been included in treatment regimens worldwide. Low dose dexamethasone is one such therapy of interest as evidenced in the RECOVERY trial,[9] the use of which however, may predispose to co-infections including parasitic infestation by inhibition of T-cell, eosinophil and plasma cell functions.[10],[11],[12] Here, we present a case report of disseminated strongyloidiasis in patient with COVID-19 treated with corticosteroids.

Strongyloidiasis is the disease caused by infection with strongyloides stercolaris which is endemic to the tropics and subtropics. It is unique among nematode infections in humans in that larvae passing in the faeces can give rise to a free-living generation of worms which in turn, is an amplification mechanism giving rise to increased numbers of infective filariform larvae in the soil. The usual mode of infection is when the filariform larvae penetrate bare skin. Autoinfection occurs when the immature rhabditiform larvae matures to filariform larvae in the intestine itself. Strongyloidiasis may present as an acute, chronic or disseminated infection.[13],[14],[15],[16]

In acute strongyloidiasis, individuals may experience local irritation, oedema or urticaria associated with the path of larval migration to the small intestine. Subsequently, in a week's time, the patient may have dry cough and/or tracheal irritation along with gastrointestinal (GI) symptoms. Chronic strongyloidiasis is often clinically asymptomatic with blood work up showing peripheral eosinophilia or elevated immunoglobulin E levels. Disseminated infection or hyperinfection syndrome is the syndrome of accelerated autoinfection usually brought about by an alteration in the immune status of the individual.[11],[12]

 Case Report

A middle aged male diabetic on oral hypoglycaemic drugs was admitted in the intensive respiratory care unit with breathlessness, haemoptysis, fever, abdominal pain and loose stools. There was a history of admission at a local facility 42 days earlier (day 1) for COVID-19 associated with bilateral pneumonia and mild ARDS. During that admission he was put on assisted non-invasive ventilation and treated with IV antibiotics, antivirals and corticosteroids as per the Kerala state COVID-19 treatment guidelines. He became COVID rapid antigen test negative on day 13 and was discharged to home care with oxygen support on day 30. At the time of current admission on day 42, the patient was started on IV antibiotics and supportive therapy. Samples were sent for microbiological investigations in subsequent days. Blood, sputum, urine and stool samples received in the laboratory were processed accordingly. Gram stain of sputum and wet mount of stool were done as preliminary investigation. Stool wet mount revealed numerous actively motile larvae which was identified as filariform larvae of strongyloides [Figure 1]. Sputum gram stain also showed larval forms [Figure 2]. A fresh sputum sample was collected, the wet mount of which showed motile strongyloides larvae [Figure 3]. Urine culture yielded Candida tropicalis and blood culture grew multidrug-resistant (MDR) Klebsiella spp.{Figure 1}{Figure 2}{Figure 3}

A diagnosis of post-COVID strongyloides hyperinfection syndrome with bacterial pneumonia was reached and oral ivermectin 200 μg/kg per day (12 mg) was added to treatment charts. Ivermectin treatment was given for one week. Repeat stool samples were devoid of strongyloides. The patient initially improved with treatment but then developed acute renal failure and respiratory failure leading to death after 24 days of second admission.


Among the reasons for immune alteration leading to disseminated strongyloides hyperinfection syndrome, treatment with corticosteroids has a particularly strong association. This is because, in addition to the effect on the immune system, corticosteroids are also thought to increase the fertility of adult female worms and accelerate the maturation of immature rhabditiform larvae to infective filariform larvae in the intestine.[11],[13] Development or exacerbation of GI and pulmonary symptoms, and detection of high numbers of larvae in stool and/or sputum is the hallmark of hyperinfection. The patient may also progress towards sepsis brought about by enteric bacteria carried by the filariform larvae to extraintestinal sites.[13] The vitals and investigations at admission are shown in [Table 1].{Table 1}

The mainstay of diagnosis of stronglyloidiasis remains the detection of larvae in stool, GI samples and/or sputum by parasitological methods. The detection of antibodies by immunological methods has a high negative predictive value. Antigen detection in stool (coproantigen) is largely limited to the realm of research. Molecular diagnostic techniques have a high degree of specificity and sensitivity, but the use is limited by cost and availability.[13] Our patient had MDR Klebsiella spp. isolated from blood culture which might have been an isolated infection or a Gram-negative sepsis initiated by the disseminating larvae.

Oral ivermectin (200 μg/kg) is the treatment of choice as it targets both adult worms and larvae. Albendazole and thiabendazole are alternatives for treatment but has largely been replaced by ivermectin due to a lack of activity against larvae of the former and GI side effects of the latter.[13],[17],[18] Hyperinfection syndrome is to be considered a potential medical emergency and may necessitate antibiotic therapy (based on institutional antibiogram of GI infections) in addition to specific anti strongyloides therapy.

In the case of our patient who is a shopkeeper by profession, there was a history of itchy skin lesion over the right leg, one month before admission to the hospital with COVID-19. Alteration of the immune status of this patient resulting from treatment with corticosteroids, underlying type 2 diabetes mellitus and SARS CoV-2 infection might have predisposed him to the development of hyperinfection syndrome.


In this time when COVID-19 treatment guidelines and options are ever changing, our case highlights the probability of strongyloidiasis presenting as one of the co-infection/super-infection, especially in the endemic areas in the setting of administration of immune altering therapies. The possibility of hyperinfection syndrome presenting as Gram-negative sepsis should also be borne in mind. Ivermectin along with appropriate antibiotic therapy is essential in the management of strongyloidiasis in the setting of COVID-19. More cases may not have been apparent previously since earlier state COVID-19 treatment guidelines included administration of Ivermectin along with corticosteroids.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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