RESUMEN
The antigenic heterogeneity of Orientia in India is still unknown in many disease endemic areas. The present study aims to characterize the strains of O. tsutsugamushi circulating in Nagaland, Northeast India. Two patients clinically diagnosed with ST and hospitalized in Mon district hospital, Nagaland were identified from whom eschar tissues were collected. Both patients demonstrated antibodies against O. tsutsugamushi along with positive PCR amplification for 56 âkDa gene. The prototype strain TA763 shared 90.4% homology with the sequences. Both the sequences formed a distinctive cluster demonstrating 100% similarity with strains identified from Thailand, Vietnam, China and southern parts of India.
Asunto(s)
Orientia tsutsugamushi , Tifus por Ácaros , Humanos , India/epidemiología , Orientia tsutsugamushi/genética , Filogenia , Reacción en Cadena de la Polimerasa , Tifus por Ácaros/diagnóstico , Tifus por Ácaros/epidemiología , Análisis de Secuencia de ADNRESUMEN
BACKGROUND: Flea-borne rickettsioses have been limitedly explored in the Indian sub-Himalayan belt, including the North Eastern Region (NER) of India. This study investigates the presence of rickettsiae hosts and their probable pathogens in the disease-endemic hilly state of the NER of India. METHODS: Entomological surveys were carried out in disease-reporting localities in a hilly state in India. Fleas collected from domesticated animals were processed for detection of a Rickettsia-specific 17-kDa gene. RESULTS: Sequence analysis revealed Rickettsia felis in six flea pools (40%), Candidatus Rickettsia senegalensis in two pools (13.3%) and Rickettsia asembonensis in one pool (6.6%). CONCLUSIONS: Our findings suggest Ctenocephalides felis, Ctenocephalides canis and Pulex irritans as potential carriers of R. felis and R. felis-like organisms in India.
Asunto(s)
Ctenocephalides , Infestaciones por Pulgas , Infecciones por Rickettsia , Rickettsia felis , Rickettsia , Siphonaptera , Animales , Ctenocephalides/microbiología , Infestaciones por Pulgas/epidemiología , Infestaciones por Pulgas/veterinaria , Humanos , Rickettsia/genética , Infecciones por Rickettsia/epidemiología , Infecciones por Rickettsia/microbiología , Infecciones por Rickettsia/veterinaria , Rickettsia felis/genética , Siphonaptera/microbiologíaRESUMEN
A cross-sectional survey was undertaken to estimate seroprevalence of immunoglobulin G antibodies against scrub typhus, spotted fever group rickettsiae, and typhus group rickettsiae in randomly selected 48 clusters in 12 districts of 3 Northeast states of India: Assam, Meghalaya, and Tripura. Individuals in 3 age groups (5-8, 9-17, and 18-45 years) were selected from each cluster. Sera (N = 2360) tested were collected as part of a national survey on dengue seroprevalence conducted between September 2017 and February 2018. Overall, seroprevalence of 2.5% was detected against rickettsioses, with highest positivity against spotted fever group rickettsiae, followed by scrub typhus and typhus group rickettsiae. Seroprevalence was highest in Tripura (3.7%), followed by Assam (2.6%) and Meghalaya (1.04%). Adults of 18 to 45 years of age were found to be most affected (3.8%). The study findings indicate the need for increasing testing facilities for active case detection at hospital levels. Efforts on implementing effective preventing strategies are suggested to be targeted in disease-specific endemic foci.