Browsing by Author "Eremeeva, M.E."

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Contribution of rickettsioses in Sri Lankan patients with fever who responded to empirical doxycycline treatment
(Oxford University Press, 2010) Premaratna, R.; Rajapakse, R.P.V.J.; Chandrasena, T.G.A.N.; Nanayakkara, D.M.; Bandara, N.K.B.K.R.G.W.; Kularatne, S.A.M.; Eremeeva, M.E.; Dasch, G.A.; de Silva, H.J.
Twenty-eight febrile Sri Lankan patients with undiagnosed fever for 7 days after hospital admission, who responded to empirical treatment with doxycycline, were retrospectively investigated using microimmunofluorescence assay to verify whether they had rickettsial infection. Eleven (39%) patients were confirmed as having spotted fever group rickettsioses and 10 (36%) as having Orientia tsutsugamushi. Seven were negative for all tests. This suggests that greater use of doxycycline appears justified for patients with undiagnosed fever in settings where rickettsial diseases are endemic or re-emerging with inadequate diagnostic facilities.
Etiology of fever of unknown origin in a selected group of Sri Lankan patients with prompt responses to Doxycycline
(Centers for disease control and Prevention, 2008) Dasch, G.A.; Premaratna, R.; Rajapakse, R.P.; Chandrasena, T.G.A.N.; Eremeeva, M.E.; de Silva, H.J.
BACKGROUND: Most patients with long duration of fever go undiagnosed in settings where diagnostic facilities are inadequate. Untreated rickettsial infections cause extended fevers; while both scrub typhus and tick typhus are re-emerging diseases in Sri Lanka, laboratory facilities to specifically diagnose rickettsial infections in Sri Lanka are not available. METHODS: We collected 2 ml venous blood from febrile patients who had no etiological diagnosis after 7 days of hospital admission, but who showed rapid clinical response to doxycycline, to verify whether they had experienced a rickettsial infection. Acute serum samples were analysed using IFA for rickettsial infections caused by Orientia tsutsugamushi, Rickettsia conorii and Rickettsia typhi. A positive IgG IFA titer >1:128 was used to define a probable case of rickettsial infection. RESULTS: 28 patients [15 males, mean age 32.5 (SD 9.2 yrs)] were studied. Mean duration of fever at admission was 6.1 days (SD 3.1). Two patients had features suggestive of encephalitis and two had erythema nodosum. Others had no specific clinical features. Routine investigations were inconclusive and blood cultures were negative. IgG-IFA titer of >128 was found in 10 for R. conorii, 6 for O. tsutsugamushi and 6 for both R. conorii and O. tsutsugamushi. None were positive for R. typhi. Six were negative for all tests. One patient with encephalitis and one with erythema nodosum had high titers for R. conorii. CONCLUSIONS: The majority of Sri Lankan patients with undiagnosed fever responding promptly to doxycycline had a rickettsial etiology. Patients with rickettsioses exhibit varied clinical presentations so greater use of doxycycline for patients with extended fevers in rickettsial-endemic settings with inadequate diagnostic facilities appears warranted. The high proportion of patients with tick typhus and antibodies against both spotted fever and scrub typhus rickettsiae was unexpected based on previous studies of patients from the same region who were confirmed to have scrub typhus by serology and by the presence of the classic eschar. It is unknown whether the etiology of tick typhus and vector(s) transmitting this agent on the Western lowland region of Sri Lanka are the same as those responsible for spotted fevers in the central hill country of Sri Lanka.
Molecular characterization of rickettsial agents in ticks (Acari: Ixodidae) from Sri Lanka
(Baltimore., 2022) Dasch, G.A.; Eremeeva, M.E.; Zambrano, M.L.; Premaratna, R.; Kularatne, S.A.M.; Rajapakse, R.P.V.J.
Because the majority of spotted fever group rickettsiae are transmitted to humans by tick bites, it is important to understand which ticks might play a role in transmission of rickettsial pathogens in Sri Lanka. The purpose of our study was to conduct molecular surveillance of 847 ticks collected in different locations in central Sri Lanka to determine which were infected with Rickettsia and Anaplasmataceae. Molecular methods were used to identify the ticks and the agents detected. Most ticks (Amblyomma, Haemaphysalis, and Rhipicephalus) were collected by flagging, and lower number was collected from dogs, cattle, pigs, a pangolin, and tortoises. Five spotted fever genotypes were identified: a Rickettsia africae-like agent in Amblyomma larvae, Rhipicephalus massiliae and a related genotype identified in association with the tropical type of Rhipicephalus sanguineus from dogs and Rhipicephalus haemaphysaloides from dogs and cattle, and Candidatus R. kellyi and another novel genotype (SL94) in R. haemaphysaloides. Twenty-three ticks were positive for Anaplasmataceae, including one Anaplasma and two Ehrlichia genotypes. Because the sequence database for both ticks and rickettsial agents from Sri Lanka and southern India is not extensive, additional molecular characterization of the tick species of Sri Lanka and their rickettsial agents is required to understand their pathogenic potential more completely. However, several of the agents we identified in this survey may well be pathogenic for humans and domestic animals, and should be considered as a part of epidemiological surveillance and patient management.
Rickettsioses presenting as major joint arthritis and erythema nodosum: description of four patients
(Springer International, 2009) Premaratna, R.; Chandrasena, T.G.A.N.; Rajapakse, R.P.V.J.; Eremeeva, M.E.; Dasch, G.A.; Bandara, N.K.B.K.R.G.W.; de Silva, H.J.
Erythema nodosum and aseptic arthritis are recognized associations of rickettsial infections. However, they usually present with a febrile illness rather than with severe arthritis. We report three patients who presented with incapacitating major joint arthritis and one who presented with severe spondyloarthropathy in addition to major joint arthritis due to serologically confirmed Orientia tsutsugamushi and Rickettsia conorii infections. All of them had erythema nodosum and low-grade fever. They had rapid clinical response to doxycycline.