Imported schistosomiasis in Europe: sentinel surveillance data from TropNetEurop

Prolonged latent schistosomiasis diagnosed 38 years after infestation in a HIV patient

We report a case of Schistosoma mansoni bilharziasis in a HIV patient 38 y after leaving an endemic region. A viable S. mansoni egg on a liver biopsy sample was diagnostic. Despite severe concomitant immunodeficiency the effective treatment was a single dose of praziquantel. Worms' intravascular longevity and the role of immunodeficiency as a possible factor in eggs retention after such prolonged latent schistosomiasis are discussed.

Early detection of Schistosoma mansoni infection by touchdown PCR in a mouse model

A detection assay for Schistosoma mansoni DNA in mouse serum samples based on touchdown PCR was developed and evaluated. The serum samples could be assayed directly without the need to extract DNA. No cross reactions between S. mansoni and related species inducing human schistosomiasis were observed. After the infection, mouse sera and feces were collected for 8 weeks. Anti-worm antigen IgG and anti-soluble egg antigen IgG were detected in the sera at 6 weeks post-infection by ELISA. The parasite's eggs were detected in the feces at 8 weeks. In contrast, S. mansoni DNA was detected in the sera at 2 weeks post-infection. These data suggest that touchdown PCR is a potential tool for the early diagnosis of S. mansoni infection.

A case of bowel schistosomiasis not adhering to endoscopic findings

Schistosomiasis is a chronic worm infection caused by a species of trematodes, the Schistosomes. We may distinguish a urinary form from Schistosomes haematobium and an intestinal-hepatosplenic form mainly from Schistosomes mansoni characterized by nausea, meteorism, abdominal pain, bloody diarrhea, rectal tenesmus, and hepatosplenomegaly. These infections represent a major health issue in Africa, Asia, and South America, but recently S mansoni has increased its prevalence in other continents, such as Europe countries and North America, due to international travelers and immigrants, with several diagnostic and prevention problems. We report a case of a 24-year-old patient without HIV infection, originated from Ghana, admitted for an afebrile dysenteric syndrome. All microbiologic studies were negative and colonoscopy revealed macroscopic lesions suggestive of a bowel inflammatory chronic disease. Since symptoms became worse, a therapy with mesalazine (2 g/d) was started, depending on the results of a bowel biopsy, but without any resolution. The therapy was stopped after 2 wk when the following result was available: a diagnosis of ""intestinal schistosomiasis" was done (two Schistosoma eggs were detected in the colonic mucosa) and this was confirmed by the detection of Schistosoma eggs in the feces. Therapy was therefore changed to praziquantel (40 mg/kg, single dose), a specific anti-parasitic agent, with complete recovery. Schistosomiasis shows some peculiar difficulties in terms of differential diagnosis from the bowel inflammatory chronic disease, as the two disorders may show similar colonoscopic patterns. Since this infection has recently increased its prevalence worldwide, it has to be considered in the differential diagnosis of our patients with gastrointestinal symptoms.

Bilharzioses invasives

Schistosomiasis is a tropical helminthic infection, observed in travelers as well as local populations. It is most often due to Schistosoma mansoni or Schistosoma haematobium and can be diagnosed at the invasive phase. Migration of the schistosomulae (larvae) in the body leads to acute parasitic toxemia, which includes a hypersensitivity reaction and circulating immune complexes. The invasive stage occurs generally 2 to 6 weeks after the exposure and combines fever, asthenia, faintness and headaches. Other signs include diarrhea, dry cough, dyspnea, urticarial rash, arthralgia, myalgia, and enlargement of liver and spleen. Although rare, neurological and cardiac complications may be fatal. This diagnosis should be considered in travelers returning from the tropics with compatible clinical signs and delayed hypereosinophilia, if they report exposure in an endemic area. It is later confirmed by seroconversion for schistosomiasis and then by observation of schistosome eggs in stool or urine (according to species). The standard treatment of acute schistosomiasis with praziquantel is ineffective and can aggravate clinical outcome during this phase. Corticosteroid treatment is recommended for serious forms with neurological or cardiac manifestations.

Schistosome infection among river rafters on Omo River, Ethiopia

BACKGROUND

Adventure trips to Africa have become more frequent, and rafting on some of the great rivers has become almost commonplace. We describe three rafting trips on the Omo River in Ethiopia, after which most of the participants were diagnosed with schistosomiasis.

METHODS

After index cases from the three groups came to medical attention, active surveillance detected outbreaks of illness in a group of American travelers (n = 18 ) in 1993 and in two groups of Israeli travelers in 1997 (n = 26).

RESULTS

Of 44 travelers, 37 were screened and 28 (76%) were infected, all with Schistosoma mansoni. Among the infected patients, 16 of 28 (57%) were symptomatic, the most frequent manifestation being fever, which occurred in 14 of 25 (56%); cough occurred in 6 of 18 (33%). Diagnosis was based on FAST-enzyme-linked immunosorbent assay, with confirmation by immunoblot. Other rafting trips on the Omo River sponsored by the same tour companies did not result in symptomatic infection. Investigation of the rafting itineraries suggested the route may have been altered from the usual for these three groups, exposing them to a part of the river that is wider, slower moving, and more densely populated.

CONCLUSIONS

Schistosomiasis should be considered in febrile patients following rafting trips in schistosome-endemic areas. As asymptomatic schistosomiasis in travelers is also common (43% in this series), all travelers exposed to freshwater in endemic areas should be encouraged to undergo serologic screening.

Burden and cost of imported infections admitted to infectious diseases units in England and Wales in 1998 and 1999

BACKGROUND

International travel from the UK has been rising, and the number of imported infections has increased. This study aimed to describe the number, nature, origin, clinical burden and cost of imported infections treated in infectious disease units (IDU) in England and Wales.

METHOD

Information about all admissions in 1998 and 1999 with illnesses considered to have been acquired during their most recent travel abroad was collected retrospectively by IDUs using a pre-piloted questionnaire.

RESULTS AND ANALYSIS

Four of the 23 IDUs in England and Wales were able to complete the questionnaires. They reported a total of 421 travel related admissions during the 2-year period. Three hundred and ninety-two of these cases were attributed to infectious causes, and of these a discharge diagnosis was made for 340 cases. The total number of bed days used to treat cases of imported infection was 2918. The most common diagnosis was malaria. The odds ratio that cases of imported infection were malaria was highest following visits to Africa. The average cost per bed day on the IDUs was around pound sterling 100, and on this basis, the total cost of treating imported infections on the four IDUs in 2 years was around pound sterling 289,000. The relative risk of acquiring an imported infection requiring treatment on an IDU was greatest for travellers to Africa.

CONCLUSIONS

From this study, the estimate of the total annual cost of IDU treatment for imported infections in England and Wales is in excess of pound sterling 800,000. Many cases may be preventable with prophylactic medication and vaccination and travel advice on risk reduction. Further information about imported infections would be useful to inform travel medicine services, other clinicians and travellers about the health risks associated with travel to specific areas, and help to target and assess the cost effectiveness of preventative measures.