[Diagnosis of infections in pneumology]

Lower respiratory tract infections rank among the leading causes of morbidity and mortality worldwide. In clinical practice, especially in the care of severely ill patients, discrimination between tracheobronchial colonisation with potentially pathogenic microorganisms and infection is a common diagnostic challenge. While prompt antibiotic treatment is needed in critically ill patients with pneumonia, an inadequate use of antibiotics is the major cause for the emergence of drug-resistant microorganisms. The first part of this review provided a detailed overview of the currently available methods for the diagnosis of pulmonary infectious diseases. In the present second part of the manuscript, we focus upon methods and criteria for the differentiation between lower respiratory tract bacterial colonisation and lower respiratory tract infections, highlighting important pathogens.

IPSE/alpha-1: a major immunogenic component secreted from Schistosoma mansoni eggs

During infection with Schistosoma mansoni the egg stage of this parasite modulates the initial T helper (Th1) response into a Th2 response. This suggests that schistosome eggs contain factors responsible for that effect. We have recently described a glycoprotein (IPSE) from S. mansoni eggs that has a potent IL-4-inducing effect on human basophils. Here we demonstrate that IPSE is identical to a previously described molecule, the S. mansoni egg antigen alpha-1. We furthermore show that the expression of IPSE/alpha-1 at the level of both mRNA and protein is restricted to the egg stage. IPSE/alpha-1 is produced in and released from the subshell area of the egg and comes into close contact with inflammatory cells recruited to the vicinity of the egg surface. In line with this IPSE/alpha-1 is one of three major S. mansoni egg glycoproteins that induce pronounced antibody responses. Its IL-4-inducing capacity, moreover, suggests that IPSE/alpha-1 plays a role in initiating the Th2 response induced by patent S. mansoni infections.

Epidemiology and clinical features of vivax malaria imported to Europe: sentinel surveillance data from TropNetEurop

BACKGROUND

Plasmodium vivax is the second most common species among malaria patients diagnosed in Europe, but epidemiological and clinical data on imported P. vivax malaria are limited. The TropNetEurop surveillance network has monitored the importation of vivax malaria into Europe since 1999.

OBJECTIVES

To present epidemiological and clinical data on imported P. vivax malaria collected at European level.

MATERIAL AND METHODS

Data of primary cases of P. vivax malaria reported between January 1999 and September 2003 were analysed, focusing on disease frequency, patient characteristics, place of infection, course of disease, treatment and differences between network-member countries.

RESULTS

Within the surveillance period 4,801 cases of imported malaria were reported. 618 (12.9%) were attributed to P. vivax. European travellers and immigrants were the largest patient groups, but their proportion varied among the reporting countries. The main regions of infection in descending order were the Indian subcontinent, Indonesia, South America and Western and Eastern Africa, as a group accounting for more than 60% of the cases. Regular use of malaria chemoprophylaxis was reported by 118 patients. With 86 (inter-quartile range 41-158) versus 31 days (inter-quartile range 4-133) the median symptom onset was significantly delayed in patients with chemoprophylaxis (p < 0.0001). Common complaints were fever, headache, fatigue, and musculo-skeletal symptoms. All patients survived and severe clinical complications were rare. Hospitalization was provided for 60% and primaquine treatment administered to 83.8% of the patients, but frequencies varied strongly among reporting countries.

CONCLUSIONS

TropNetEurop data can contribute to the harmonization of European treatment policies.

P19: a female and tissue specifically expressed gene in Schistosoma mansoni, regulated by pairing with the male

A female-specific sequence was isolated from a cDNA library of Schistosoma mansoni and further characterized. Expression of the corresponding gene (p19) depends on pairing with a male. In situ hybridization and immunohistology experiments revealed exclusive expression of the gene in the cells of the vitellarium, suggesting a function in egg formation. In addition, experimental evidence for cross-linking of the protein under oxidative conditions supports the assumption that the p19 gene may code for an egg-shell precursor protein.

Imported schistosomiasis in Europe: sentinel surveillance data from TropNetEurop

BACKGROUND

Schistosomiasis is a major parasitic disease, increasingly imported into temperate climates by immigrants from and travelers to endemic areas.

METHOD

To generate valid data on imported infectious diseases to Europe and to recognize trends over time, the European Network on Imported Infectious Diseases Surveillance (TropNetEurop) was founded in 1999. Three hundred and thirty-three reports of schistosomiasis were analyzed for epidemiologic and clinical features.

RESULTS

Male patients accounted for 64% of all cases. The average age of all patients was 29.5 years. The majority of patients were of European origin (53%). Europeans traveled predominantly for tourism (52%). Main reasons for travel for people from endemic areas were immigration and refuge (51%) and visits to relatives and friends (28%). The majority of infections were acquired in Africa; 92 infections were clearly attributable to Schistosoma haematobium, 130 to Schistosoma mansoni, and 4 to Schistosoma intercalatum. Praziquantel was the only treatment used. No deaths were recorded.

CONCLUSION

TropNetEurop sentinel provides valuable epidemiologic and clinical data on imported schistosomiasis to Europe.

Age as a risk factor for severe manifestations and fatal outcome of falciparum malaria in European patients: observations from TropNetEurop and SIMPID Surveillance Data

Previous studies have indicated that age is a risk factor for severe falciparum malaria in nonimmune patients. The objectives of this study were to reevaluate previous findings with a larger sample and to find out how strongly clinical outcomes for elderly patients differ from those for younger patients. Results of adjusted analyses indicated that the risks of death due to falciparum malaria, of experiencing cerebral or severe disease in general, and of hospitalization increased significantly with each decade of life. The case-fatality rate was almost 6 times greater among elderly patients than among younger patients, and cerebral complications occurred 3 times more often among elderly patients. Antimalarial chemoprophylaxis was significantly associated with a lower case-fatality rate and a lower frequency of cerebral complications. Women were more susceptible to cerebral complications than were men. Our study provides evidence that falciparum malaria is more serious in older patients and demonstrates that clinical surveillance networks are capable of providing quality data for investigation of rare events or diseases.

Epidemiology and clinical features of imported dengue fever in Europe: sentinel surveillance data from TropNetEurop

Travelers have the potential both to acquire and to spread dengue virus infection. The incidence of dengue fever (DF) among European travelers certainly is underestimated, because few centers use standardized diagnostic procedures for febrile patients. In addition, DF is currently not reported in most European public health systems. Surveillance has commenced within the framework of a European Network on Imported Infectious Disease Surveillance (TropNetEurop) to gain information on the quantity and severity of cases of dengue imported into Europe. Descriptions of 294 patients with DF were analyzed for epidemiological information and clinical features. By far the most infections were imported from Asia, which suggests a high risk of DF for travelers to that region. Dengue hemorrhagic fever occurred in 7 patients (2.4%) all of whom recovered. Data reported by member sites of the TropNetEurop can contribute to understanding the epidemiology and clinical characteristics of imported DF.