Fever as the presenting complaint of travellers returning from the tropics

We investigated prospectively the cause of fever in patientsrequiring hospitalization after returning from the tropics.All consecutive admissions (n=195) with oral temperature >37.0°Cat the time of admission were enrolled. Final diagnosis as recordedon the discharge summary by the attending physician and resultsof any relevant laboratory or radiological investigations wererecorded on standard proforma. Malaria accounted for 42% ofadmissions; two patients had returned to Britain more than 6months before presentation. The second largest group was assumedto have a non-specific viral infection (25%). Cosmopolitan infections(urinary tract infection, community-acquired pneumonia, streptococcalsore throat, etc.) accounted for 9%. Coincidental infections(schistosomiasis, filariasis, intestinal helminths) were foundin 16%. Serology was positive for HIV infection in 3%. The mostuseful investigation was a malaria film, which was positivein 45% of cases in which it was performed. The combination ofthrombocytopaenia (platelet count <100 x 10⁹) and hyperbilirubinaemia(bilirubin > 18 IU/ml) were useful predictive markers ofmalaria: all 23 patients with both abnormalities had positivemalaria films. Malaria must be excluded in any febrile patientreturning from the tropics. In the absence of a positive malariafilm, the combination of a low platelet count and raised bilirubinmay suggest the need for an empirical course of therapy.     

Giardia muris infection in mice with concurrent graft-versus-host reaction

The effects of concurrent graft-versus-host reaction (GvHR) on the course of Giardia infection in CBA x BALB/c F1 mice have been examined, to test the hypothesis that T-cell-mediated immunity, in the form of a local DTH reaction, alters the host-parasite relationship in favour of the host by changing the physical environment of the parasite. GvHR did not enhance immunity, indeed mice infected with Giardia at a late stage of GvHR had significantly higher faecal cyst excretion and prolongation of the plateau phase of infection, indicating a degree of immunodeficiency.     

Adult worm‐specific IgE/IgG4 balance is associated with low infection levels of Schistosoma mansoni in an endemic area

Field studies have suggested an immune‐mediated mechanism associated with resistance to Schistosoma mansoni infection. Overall, levels of specific IgE have been correlated with resistance to infection, whereas levels of IgG4 have been associated with susceptibility. This study aimed to evaluate serum levels of soluble adult worm antigen preparation (SWAP)‐specific IgE and IgG4 in relation to current infection in a large casuistic of individuals living in an endemic area of schistosomiasis in Bahia, Brazil. The prevalence of S. mansoni infection was 37·7% and the mean parasite burden was 55·4 (0–2100) epg/faeces. There was no significant difference in the levels of SWAP‐specific IgE in individuals with different parasite burden, whereas high producers of parasite‐specific IgG4 presented higher parasite burden when compared to low IgG4 producers. Additionally, S. mansoni parasite load was positively correlated with the levels of specific IgG4 or total IgE. No significant correlation was observed between parasite burden and SWAP‐specific IgE. Nevertheless, SWAP‐specific IgE/IgG4 ratio was higher in uninfected or lightly infected individuals (1–99 epg/faeces) than in heavily infected ones (≥400 epg/feces). These findings highlight the important role of IgE/IgG4 ratio in the resistance to infection, which could be useful for further studies in schistosomiasis vaccine candidates.