Acute schistosomiasis, a diagnostic and therapeutic challenge

Abstract

In non-endemic countries, acute (invasive) schistosomiasis (AS) is typically seen in non-immune travellers, whereas chronic schistosomiasis is more frequently diagnosed in immigrants. Travellers with AS initially present with non-specific signs such as fever, cough, headache, and urticaria. Life-threatening cardiac and neurological complications may occur. The positive diagnosis of AS relies on seroconversion, which appears together with hypereosinophilia approximately 3 weeks after the onset of symptoms. When prescribed during AS, praziquantel usually does not prevent the chronic phase of the disease and is associated with exacerbation of signs and symptoms in approximately 50% of cases. According to the published literature, corticosteroids may be recommended alone or in association with praziquantel. When associated with corticosteroids, pharmacokinetic interactions may impair the efficacy of praziquantel. We suggest that corticosteroids should be restricted to use in patients with systemic complications of AS, whereas praziquantel should be initiated only when ova are detected in either stools or urine, depending on the culprit species.

Early Detection of Schistosoma Egg–Induced Pulmonary Granulomas in a Returning Traveler

“…The symptomatic acute phase, mostly limited to nonimmune subjects, may include pulmonary manifestations mimicking other helminthic diseases (e.g., Loeffler syndrome). [4][5][6][7] Pavlin and others 8 identified, over a retrospective chart review, 89 cases of acute pulmonary schistosomiasis (APS) in travelers. Patients reported dry cough with dyspnea, wheeze, or chest pain, occurring within 2-8 weeks after exposure and healing within a few weeks/months.…”

Evaluation of Eight Serological Tests for Diagnosis of Imported Schistosomiasis

“…During early stages, schistosome infections might cause severe manifestations, such as Katayama fever, schistosomal myeloradiculopathy, and pneumonitis (6,7,25,28,37). However, up to 50% of newly infected patients remain asymptomatic (29,35,45).…”

“…First, those patients seem to be more prone to acute manifestations, which occur during early stages of infection and sometimes during the prepatent period (18). Furthermore, exposure to cercarial larvae is usually limited, resulting in infections with low parasite loads (11,25,28). Therefore, direct parasitological methods often fail (11).…”

“…Therefore, direct parasitological methods often fail (11). For this patient group, serological tests detecting antischistosomal antibodies are an important diagnostic tool (26,38,44), although the "seronegative window" has to be considered in very early infections (9,25,43).…”

There will be an answer; let it bleed

“…27,28 Praziquantel is ineffective against eggs and immature worms 18,19 and may worsen the symptoms of AS if employed without steroids. 29 …”