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PLoS Neglected Tropical Diseases Sep 2020Murine typhus is an acute febrile, flea-borne disease caused by the bacteria Rickettsia typhi. The disease occurs worldwide but is likely underrecognized due to its...
Murine typhus is an acute febrile, flea-borne disease caused by the bacteria Rickettsia typhi. The disease occurs worldwide but is likely underrecognized due to its non-specific symptoms, causing significant morbidity. A systematic review found disease complications in one-fourth of all patients and a long fever duration in those untreated. Although mortality in treated cases is estimated to be very low, some case series have shown a notably higher mortality in untreated patients. This study aimed to describe the outcomes and estimate the mortality of untreated murine typhus through a comprehensive systematic literature review. We systematically searched the literature for articles describing untreated murine typhus patients, excluding cases with no laboratory assay confirmed diagnosis, those who received efficacious treatment, had incomplete information on primary outcome and articles describing less than 10 patients and performed a narrative synthesis of the study findings. The study protocol followed the PRISMA guidelines and was part of a more extensive protocol registered at PROSPERO (CRD42018101991). Twelve studies including a total of 239 untreated patients matched the eligibility criteria. Only a single study reported one death in 28 patients, giving a patient series mortality of 3.6% and an overall mortality of 0.4% in 239 untreated patients. Complications were reported in 10 of the 12 studies and included involvement of the central nervous system, kidney and lung, with a hospitalisation rate of 70% and ICU admission rate of 27% in one study. The mean duration of fever in untreated patients was 15 days in two and 12.7 days in one study. Although the untreated mortality in this study was low, the sample size was small. Murine typhus caused significant morbidity when untreated, leading to high hospitalisation rates and highlighting the importance of early diagnosis and treatment of this neglected disease to reduce disease burden and health-care related costs.
Topics: Databases, Factual; Fever; Hospitalization; Humans; Mortality; Rickettsia typhi; Treatment Outcome; Typhus, Endemic Flea-Borne
PubMed: 32925913
DOI: 10.1371/journal.pntd.0008641 -
The American Journal of Tropical... Jul 2020Murine typhus is a neglected but widespread infectious disease that results in acute fever. The immunofluorescence assay (IFA) is the "gold standard" to identify IgM or...
Murine typhus is a neglected but widespread infectious disease that results in acute fever. The immunofluorescence assay (IFA) is the "gold standard" to identify IgM or IgG antibodies, although there is a lack of standardization in methodologies. The objective of this review is to summarize 1) the differences in published methodologies, 2) the diagnostic cutoff titers, and 3) the justification of diagnostic cutoffs. Searches were performed by combining the following search terms: "murine typhus," "," "immunofluorescence," "IFA," and "serologic" with restrictions (i.e., "" or "murine typhus," and "IFA" or "immunofluorescence," or "serologic*"). The search identified 78 studies that used IFA or immunoperoxidase assay (IIP) antibody cutoffs to diagnose murine typhus, 39 of which were case series. Overall, 45 studies (57.7%) provided little to no rationale as to how the cutoff was derived. Variation was seen locally in the cutoff titers used, but a 4-fold or greater increase was often applied. The cutoffs varied depending on the antibody target. No consensus was observed in establishing a cutoff, or for a single-value diagnostic cutoff. In conclusion, there is a lack of consensus in the establishment of a single-value cutoff. Further studies will need to be executed at each distinct geographic location to identify region-specific cutoffs, while also considering background antibody levels to distinguish between healthy and infected patients.
Topics: Antibodies, Bacterial; Fluorescent Antibody Technique; Humans; Immunoglobulin G; Immunoglobulin M; Neglected Diseases; Predictive Value of Tests; Rickettsia typhi; Typhus, Endemic Flea-Borne
PubMed: 32274984
DOI: 10.4269/ajtmh.19-0818