Rickettsiae in Myanmar (Rickettsiae)
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ClinicalTrials.gov Identifier: NCT03847870 |
Recruitment Status :
Completed
First Posted : February 20, 2019
Last Update Posted : January 13, 2020
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Condition or disease | Intervention/treatment |
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Rickettsiae Infections | Diagnostic Test: MORU in-house ELISA test followed by IFA if positive |
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:
- Himalaya general clinic, Puta-O, Kachin;
- Lily general clinic, Thanbyuzayat, Mon;
- Orchid general clinic, Hlaing Thar Yar, Yangon;
- Winka general clinic, Winka, Kayin;
- Monywa Hospital, Sagaing;
- Mandalay General Hospital and University of Medicine, Mandalay;
- Magway General Hospital, Magway This is a minimal risk study. The participants will not have to undergo any additional procedures, since we will be using leftover blood samples that have been collected for routine clinical tests to study the background levels of previous rickettsial infections. Participation in this study is voluntary. Subjects who decline to participate will have no impact on the care they receive at the hospital or clinic. There will be no incentives or compensation for study participation.
Study Type : | Observational |
Actual Enrollment : | 700 participants |
Observational Model: | Other |
Time Perspective: | Cross-Sectional |
Official Title: | Background Seroprevalence of Rickettsial Infections in Myanmar |
Actual Study Start Date : | June 20, 2019 |
Actual Primary Completion Date : | October 25, 2019 |
Actual Study Completion Date : | October 25, 2019 |
- Diagnostic Test: MORU in-house ELISA test followed by IFA if positive
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 [ Time Frame: January, 2020 ]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).
- Patient characteristics associated with rickettsial infections [ Time Frame: January, 2020 ]Correlation of different patient characteristics with a positive ELISA and IFA test indicating a previous rickettsial infection.

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Ages Eligible for Study: | Child, Adult, Older Adult |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Sampling Method: | Non-Probability Sample |
Inclusion Criteria:
- Male and female, all age groups, requiring a blood draw for a routine clinical purpose
Exclusion Criteria:
- Leftover blood sample of less than 500μL

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03847870
Myanmar | |
Myanmar Oxford Clinical Research Unit | |
Yangon, Myanmar |
Principal Investigator: | Elizabeth Anne Ashley, Dr | Myanmar Oxford Clinical Research Unit | |
Principal Investigator: | Stuart Blacksell, Prof | Mahidol Oxford Tropical Medicine Research Unit | |
Study Director: | Philip Elders, MSc | Myanmar Oxford Clinical Research Unit | |
Study Director: | Wei Yan Aung Htay, Dr | Myanmar Oxford Clinical Research Unit | |
Study Director: | Yin Yin Htwe, Dr | National Health Laboratory, Myanmar | |
Study Director: | Myat Myat Moe, Dr | Magway General Hospital, Magway | |
Study Director: | Wai Mon Kyaw, Dr | Monywa Hospital, Sagaing | |
Study Director: | Ni Ni Zaw, Dr | Mandalay General Hospital and University of Medicine, Mandalay | |
Study Director: | Win May Thein, Prof | Mandalay General Hospital and University of Medicine, Mandalay | |
Study Director: | Thin Thin Nwe, Prof | University of Medicine, Magway | |
Study Director: | Kyaw Soe, BSc | Myanmar Oxford Clinical Research Unit | |
Study Director: | Ampai Tanganuchitcharnchai, BSc | Mahidol Oxford Tropical Medicine Research Unit | |
Study Director: | Ni Ni Tun, Dr | Myanmar Oxford Clinical Research Unit and Medical Action Myanmar | |
Study Director: | Frank Smithuis, Prof | Myanmar Oxford Clinical Research Unit and Medical Action Myanmar |
Responsible Party: | Myanmar Oxford Clinical Research Unit |
ClinicalTrials.gov Identifier: | NCT03847870 |
Other Study ID Numbers: |
OXTREC 552-18 |
First Posted: | February 20, 2019 Key Record Dates |
Last Update Posted: | January 13, 2020 |
Last Verified: | January 2020 |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
rickettsiae seroprevalence |
Infections Rickettsia Infections Rickettsiaceae Infections Gram-Negative Bacterial Infections |
Bacterial Infections Bacterial Infections and Mycoses Vector Borne Diseases |