Ranganathan Krishnamoorthi

• Master of Science
• SENIOR TECHNICAL OFFICER at INDIAN COUNCIL OF MEDICAL RESEARCH- VECTOR CONTROL RESEARCH CENTRE

Objective To identify the risk factors for acquiring scrub typhus infection among all age group. Methods A case-control study was carried out from June to December 2019 in collaboration with the Department of Health Services, Kerala. 136 Of serologically confirmed scrub typhus reported during 2018 were included and 270 age and sex-matched healthy...

Background Anxiety disorders, bipolar disorder, and depression are prevalent mental health issues that have a substantial impact on both individuals and the community. Many people continue to have symptoms and do not get the right kind of relief from their existing drugs, even after trying conventional therapy methods. Therefore, to enhance the cur...

Background objectives: Scrub typhus, caused by Orientia tsutsugamushi present in small mammals harbouring the ectoparasites. A study was undertaken to detect the pathogen present in small mammals and its ectoparasites in the scrub typhus-reported areas. Methods: The small mammals (rodents/shrews) and its ectoparasites were screened for O. tsutsu...

Ticks are large chelicerate, ectoparasitic vectors belonging to arthropods causing several zoonotic tick-borne diseases leading to morbidity or even mortality in both humans and animals worldwide. From India, 125 species are recorded which is more than one-eighth of the 982 tick species, belonging to 24 genera (10 from India) and 4 families namely...

A survey was conducted to determine the human tick-borne bacterial infections in the nymphs which were collected from Western Ghats’ fringe forest areas. Tick nymphs were collected using the flagging method from the villages where cases Kyasanur Forest Disease (KFD) were previously reported in the states of Goa, Karnataka and Maharashtra. A total o...

Background: Rodents and shrew living in the vicinity of human beings perform significant role to harbor different spe­cies of ectoparasites and thus act as the reservoir host for the spread of diseases to human and animals. Methods: This study was undertaken to determine the species composition of the medically important ectoparasites present in t...

The species composition and host preference of medically important fleas monitored in urban, semi-urban, and rural revealed 412(65%) and 222(35%) fleas. From urban and rural habitats 90 and 345 fleas were collected respectively. There was a significant difference between urban and rural habitats in flea abundance. From rodents and domestic animals...

Chiggers, the larval Trombiculid mites are the vectors for scrub typhus. Rodents and shrews are the preferred host. Study made at different habitats of chiggers collected in rodents and shrews, revealed more number to Rattus rattus 95(63%) and Suncus murinus 33(22%). Rattus rattus 31(54%) and Suncus murinus 17(30%) alone contributed more in chigger...

This is a rapid protocol proposed after its prolonged usage for the clearing, staining, and mounting of the medically important hematophagous ectoparasites obtained from human and small mammals collected in Tamil Nadu and Kerala, India. During the biodiversity study on ectoparasites, this altered protocol improved significantly the visibility of th...

Background & objectives: Scrub typhus, an acute febrile Rickettsial disease is caused by the bacterial pathogen Orientia tsutsugamushi which is spread by the bite of infected chigger mite vectors belonging to the family Trombiculidae. A study was undertaken to find out the prevalence of scrub typhus among the indigenous population from Nilgiris, T...

Background & objectives: Dengue emerged as an important public health problem in Tamil Nadu from 2000 onwards, reported in all the districts as an endemic disease of Tamil Nadu except Nilgiris district. So this study was carried out to understand the dengue epidemiology in Nilgiris district. Methods: Block-wise study was made at the Nilgiris dis...

Background & objectives: Scrub typhus is caused by Orientia tsutsugamushi and transmitted by larval trombiculid chigger mites. Rodents and shrews are hosts for chigger mites in the transmission to humans. Wonder and Sherman traps are widely used for trapping rodents and shrews for the collection of ectoparasitic chigger mites. A comparative trappin...

Scrub typhus cases have been reported in Madurai, but very little is known about the distribution patterns of ectoparasites on rodents and shrews in the Madurai district. To determine the chigger vectors of scrub typhus, Rattus rattus, R. norvegicus, Mus musculus, and Suncus murinus were collected from these areas and the prevalence and mean intens...

The main goal of this investigation was to record the ectoparasites living on rodents in scrub typhus endemic areas of Kerala state, India. Rodents captured alive using Sherman and wonder traps from four diverse habitations revealed, a total of 59 rodents/shrews constituted by 5 host species from families Muridae and Soricidae. In total, 1135 ectop...

This study was carried out in Madurai district, Tamil Nadu State, South India. Ticks were collected from cows, dogs, goats, cats, and fowls. The overall percentage of tick infestation in these domestic animals was 21.90%. The following ticks were identified: Amblyomma integrum, Haemaphysalis bispinosa, Haemaphysalis paraturturis, Haemaphysalis turt...

A brief note on the Mite and Tick research

After a gap of 25 years the Centre for Research in Medical Entomology (CRME) surveyed the mosquito biodiversity in the tail-end hill ranges of the Western Ghats, viz., Kanyakumari (Keeriparai) and Tirunelveli districts (Kalakkad-Mundanthurai Tiger Reserve (KMTR) and Courtallam) of Tamil Nadu between July 2010 and June 2013. The altitude of the hill...

After a gap of 25 years the Centre for Research in Medical Entomology (CRME) surveyed the mosquito biodiversity in the tail-end hill ranges of the Western Ghats, viz., Kanyakumari (Keeriparai) and Tirunelveli districts (Kalakkad-Mundanthurai Tiger Reserve (KMTR) and Courtallam) of Tamil Nadu between July 2010 and June 2013. The altitude of the hill...

The genus Toxorhynchites (Tribe Toxorhynchitini), comprising 89 species worldwide which are organized under four subgenera (Afrorhynchus, 19 species; Ankylorhynchus, 4 species; Lynchiella, 16 species and Toxorhynchites, 50 species), is characterized by mosquitoes that do not feed on blood; instead they subsist on variety of plant juices and have th...

The Western Ghats hill ranges in Indian peninsula are one of the 25 hot spots in the world. Western Ghats hill ranges are rich with fauna and flora. This study was carried out in 11 hill ranges of Western Ghats falling in three States of South India, by the Centre for Research in Medical Entomology (CRME) Madurai, during July 2010 to October 2013....

Mosquito faunal surveys were carried out in different habitats of 11 hill ranges of the Western Ghats between 2000 and 2012. Thirty three anopheline species were examined and recorded out of 8730 specimens belonging to subgenera Anopheles (12) and Cellia (21). Very low densities of malaria vectors Anopheles (Cellia) fluviatilis (0.7%) and An. (Cel....

Dengue is highly endemic in Chennai city, South India, in spite of continuous vector control efforts. This intervention study was aimed at establishing the efficacy as well as the favouring and limiting factors relating to a community-based environmental intervention package to control the dengue vector Aedes aegypti. A cluster randomized controlle...

In 2001, a major dengue outbreak was recorded in Chennai city, with 737 cases (90%) out of a total of 861 cases recorded from Tamil Nadu state. A KAP survey was carried out to assess the community knowledge, attitude and practice on dengue fever (DF), following the major dengue outbreak in 2001. A pre- tested, structured questionnaire was used for...

An outbreak of chikungunya fever characterized by prolonged incapacitation in the Lakshadweep islands in Indian Ocean occurred in November 2006. We undertook the entomological and epidemiological investigations on the Chikungunya outbreak in the Lakshadweep islands, Indian Ocean. Epidemic information in the affected places was obtained from the loc...

Virological investigation was carried out to determine the etiology of suspected Chikungunya fever among humans reported in the Lakshadweep islands in the Indian Ocean. Three out of 23 acute sera samples showed cytopathological changes in Vero cell lines. Further, indirect immunofluorescence antibody test and reverse transcriptase-polymerase chain...