Schistosoma haematobium causing pulmonary schistosomiasis in a returning traveller

Pulmonary infections in the returning traveler

PURPOSE OF REVIEW

The recent COVID-19 pandemic has shaped the epidemiology of other infectious diseases globally. International tourist arrivals are increasing and recovering to prepandemic levels. This review focuses on respiratory infections in travelers, highlighting the characteristics of the main imported viral, bacterial, fungal, and parasitic infections with pulmonary involvement.

RECENT FINDINGS

A recent systematic review estimated a prevalence of respiratory symptoms in travelers of around 35%, increasing to nearly 65% in the context of mass gatherings. Common viral and bacterial pathogens account for the majority of respiratory infections with an identified cause; however, recent data focus on the need for surveillance of emerging infections such as MERS-CoV, henipaviruses and multidrug resistant bacteria, which may be spread through travel. Fungal and parasitic respiratory infections are less common, and acquisition is usually associated with specific risk factors or exposure in endemic areas. Special risk groups, such as immunocompromised travelers, may be particularly vulnerable, presenting with severe disease or reactivation of latent infections.

SUMMARY

The next significant international epidemic could involve another new infectious agent causing respiratory disease and spreading via mobile populations. Official protocols should be adhered to, and public health interventions implemented for effective control. Continued and globally coordinated investments in research for new vaccines, therapeutic agents, disease modeling, and digital tracking strategies are essential.

Schistosoma haematobium infection with pulmonary involvement in a traveller returning from Congo: A case report and systematic review of literature on nodular pulmonary schistosomiasis

BACKGROUND

Schistosomiasis is highly prevalent in sub-Saharan Africa and diagnosis is difficult for travel medicine practitioners, because it can affect different organs with atypical manifestations. S. haematobium is mostly associated with urinary involvement and rarely with pulmonary lesions. This review aims to summarise the pulmonary forms associated with schistosomiasis, especially with S. haematobium.

METHOD

Based on a case report of both pulmonary and urogenital schistosomiasis, we performed a systematic literature review of schistosomiasis occurring in migrants and travellers, with a specific focus on pulmonary schistosomiasis.

RESULTS

Pulmonary schistosomiasis can present two different clinical patterns. On the one hand, there is an acute pattern, which more frequently affects non-immune young travellers within three to eight weeks of their return and, on the other hand, there is a chronic pattern, which has been evolving in recent years and which mostly affects people living in endemic areas or migrating from these countries. Nodular pulmonary lesions are described in both patterns. Genus identification should not focus only on known patterns, and identification of S. haematobium should not be associated exclusively with urinary schistosomiasis.

CONCLUSIONS

Pulmonary schistosomiasis, even when resulting from S. haematobium, is a rare but existing infection that appears to be spreading with increasing travel and global migration. Physicians need to be more aware of non-specific symptoms that may reveal an atypical presentation of a tropical disease, in order to avoid the chronic complications which can result from parasitic diseases.

New Insights on Acute and Chronic Schistosomiasis: Do We Need a Redefinition?

A precise timeframe to differentiate acute schistosomiasis (AS) and chronic schistosomiasis (CS) is not well defined. Based on recent published literature, lung nodular lesions in AS and CS seem to have the same pathophysiology, that is, eggs laid in situ by adult worms, during an ectopic migration. Moreover, the occurrence of lung nodules due to clusters of eggs and the systemic immunoallergic reaction of AS (Katayama syndrome) may be two separate clinical entities, which may overlap during the early phase of infection. Consequently, the classical distinction between AS and CS loses much of its conceptual validity. If adult worms play a more important role in the early phase of the disease the clinical management of AS should probably be revised.