An observational study in Rickettsiae Infections, sponsored by Myanmar Oxford Clinical Research Unit. Completed at 1 site in Burma. Per ClinicalTrials.gov, last updated 2020-01-13.
Sponsored by Myanmar Oxford Clinical Research Unit · Observational
Rickettsial infections have been found to be the second most common cause of non-malarial febrile illness in Southeast Asia, just after dengue, and are largely neglected treatable causes of morbidity and mortality. The rickettsiae can be divided into three major groups: the scrub typhus group (STG), the typhus group (TG) and the spotted fever group (SFG). Rickettsial infections typically present with an acute fever and are difficult to diagnose due to the many different causes of undifferentiated fever in Southeast Asia. Rickettsial IgG seroprevalence, reflecting past infection, will give an estimate of the burden of rickettsial infections in the population. Background seroprevalence studies in countries around Myanmar have found high rates of rickettsial infections. Yet, in Myanmar there have been no prevalence studies on rickettsial infections since the Second World War. We plan to determine IgG levels to the three different groups of rickettsial infections in leftover blood samples in several clinics and hospitals in different regions of Myanmar.
Rickettsial infections have been found to be the second most common cause of non-malarial febrile illness in Southeast Asia, just after dengue, and are largely neglected treatable causes of morbidity and mortality. The rickettsiae can be divided into three major groups: the scrub typhus group (STG), the typhus group (TG) and the spotted fever group (SFG). Rickettsial infections typically present with an acute fever and are difficult to diagnose due to the many different causes of undifferentiated fever in Southeast Asia. Rickettsial IgG seroprevalence, reflecting past infection, will give an estimate of the burden of rickettsial infections in the population. The current best test for IgG serological diagnosis of previous rickettsial infections is the indirect immunofluorescence assay (IFA). IFA has several limitations
in that it is difficult to standardize due to operator subjectivity, it needs appropriate local diagnostic cut- offs and requires improvement in terms of standardization and ease of use. An alternative serological test that is cheaper and is easier to use is the enzyme-linked immunosorbent assay (ELISA), which is more suited to screen for the burden of rickettsial diseases in low-resource countries. Background seroprevalence studies in countries around Myanmar have found high rates of rickettsial infections. Yet, in Myanmar there have been no prevalence studies on rickettsial infections since the Second World War. We plan to determine IgG levels to the three different groups of rickettsial infections in leftover blood samples in several clinics and hospitals in different regions of Myanmar. Participants with leftover blood samples after having undergone a blood draw for any clinical reason or a blood donation will be requested to participate in the study. The participant will be informed about the study and requested to provide informed consent when agreeing to participate. The leftover sample will be anonymized and frozen. The gender, age and location of clinic/hospital of the participant will be recorded. All samples will be tested for IgG antibodies using an in-house ELISA test in the Mahidol Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand for scrub typhus (Orientia tsutsugamushi strains Karp, Kato, Gilliam and TA716), murine typhus (Rickettsia typhi strain type Wilmington), and spotted fever rickettsioses (Rickettsia honei and Rickettsia conorii). If the sample tests positive for IgG antibodies, an IFA test will be performed as the gold standard reference test to confirm the finding. The anonymous samples will be discarded as soon as they are no longer needed for the study. The population investigated will be 700 patients attending seven different clinics and hospitals in different regions of Myanmar with each site including 100 patients.
We will include patients at the following study sites:
Myanmar Oxford Clinical Research Unit is the lead sponsor of 6 studies on the registry; none are open to participants now.
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The population investigated will be patients who had a leftover samples from routine clinical blood draw when attending seven different Medical Action Myanmar (MAM) clinics and hospitals in different regions of Myanmar with each site including approximately 100 patients.
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Exclusion Criteria:
An in-house rickettsial IgG ELISA test will be used for this study to determine previous rickettsial infections by measuring IgG levels. All specimens will be tested for IgG antibodies using ELISA tests for scrub typhus (Orientia tsutsugamushi strains Karp, Kato, Gilliam and TA716), murine typhus (Rickettsia typhi strain type Wilmington), and spotted fever rickettsiosis (Rickettsia honei and Rickettsia conorii). If the sample tests positive, it will be retested for the same antigens using the IFA test. The sample will be considered positive if both the ELISA and the IFA are positive.
Positive ELISA confirmed by positive IFA
Proportion of patients with a positive IgG ELISA, subsequently confirmed with IFA, for scrub typhus (Orientia tsutsugamushi strains Karp, Kato, Gilliam and TA716), murine typhus (Rickettsia typhi strain type Wilmington), and spotted fever rickettsiosis (Rickettsia honei and Ricketsia conorii).
Time frame: January, 2020
Patient characteristics associated with rickettsial infections
Correlation of different patient characteristics with a positive ELISA and IFA test indicating a previous rickettsial infection.
Time frame: January, 2020
This study is completed, as verified in Jan 2020. You cannot join it, but the record below documents what was studied.
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Myanmar Oxford Clinical Research Unit