Rattus Tanezumi Research Articles

Rats and their helminth parasites: Potential zoonosis threats of land use change in the northeastern sub-watersheds of Mount Makiling, Laguna, Philippines.

The continuous challenges of land use change have brought potential threats to biodiversity and the spread of zoonotic diseases. In this study, synanthropic rodents and their helminth parasites were used as sentinels to assess the potential impact of land use on zoonosis. Rats were collected in different ecosystems, namely agricultural, agroforest, and residential areas in the northeastern sub-watersheds of Mount Makiling, Laguna, Philippines. Three (3) species of rats were captured, namely, Rattus tanezumi, Rattus norvegicus, and Rattus exulans. Of the total 180 rats collected, 92.7 % were found infected with helminth parasites, namely Hymenolepis diminuta, Hymenolepis nana, Taenia pisiformis, and Strobilocercus fasciolaris (cestodes); Angiostrongylus cantonensis, Nippostrongylus brasiliensis, Strongyloides ratti, Capillaria hepatica, Trichuris muris, and Rictularia sp. (nematodes); and Echinostoma ilocanum (trematode). Of these 11 species, nine (9) were considered zoonotic. This study provides important information on the helminth parasites of rats in the northeastern sub-watersheds of Mount Makiling and the potential threat of zoonotic transmission due to increasing land use change and urbanization in the area. Moreover, urbanization can provide favorable eco-epidemiological conditions for rodent-borne pathogens, such as parasites, that are seriously threatening agricultural settings and human settlements in these areas.

Rat composition and population in mature oil palm adjacent to paddy field

Rat is one of the main pests in an oil palm plantation, impacted at various types and stages of oil palm growth. Ungkaya estate has a historical & endemic infestation of rats, especially in several fields adjacent to paddy fields. This study aimed to find out the seasonal migration of rats from paddy fields to oil palm fields in Ungkaya Estate. Five plots were used for trapping, identifying rat species, monitoring of rat population, rat damage intensity, and rat habitat preference at each stage of the paddy season. Trapped rats were identified as Rattus tiomanicus (56.91%), Rattus argentiventer (36.17%), and Rattus tanezumi (6.91%). The intensity of rat damage to the palm was high during the vegetative phase of paddy season and the full moon phase. The regression analysis results showed that the number of trapped rats has a positive relationship to rat damage intensity for the vegetative and harvesting stage at full moon. The number of trapped R. argentiventer at vegetative stage was higher than the generative & harvesting phase of the paddy season. Moreover, there were rat footprints observed on the riverside leading to the oil palm field. The results of all observation parameters concluded that there was seasonal migration of rats between the oil palm fields and the paddy fields in Ungkaya estate. The information is pivotal in drawing up suitable mitigation measures to control and minimize rat damage to the oil palm.

Population structure, dispersion patterns and genetic diversity of two major invasive and commensal zoonotic disease hosts (Rattus norvegicus and Rattus tanezumi) from the southeastern coast of China.

Background: The invasive brownrat (Rattus norvegicus) and the Oriental rats (Rattus tanezumi) are common commensal murid that are important hosts for rodent-borne diseases in southeast Asia. Understanding their population structure and genetic diversity is essential to uncover their invasion biology and distribution dynamics that are essential for controlling rodent-borne diseases. Methods: TA total of 103 R. norvegicus and 85 R. tanezumi were collected from 13 to 9 coastal areas of six provincial monitoring sentinel sites, respectivelyto assess patterns in their microsatellite loci and their mitochondrial coxl gene region. Results: Eleven sampled populations of R. norvegicus were divided into two major clusters by region. The observed heterozygosity values of all regional populations were smaller than expected genetic diversity heterozygosity values and deviated from Hardy-Weinberg equilibrium Nine sample populations of R. tanezumi were divided into three clusters; two that included sample from Hainan and Fujian provinces, and one that included samples from the other provinces and cities. The genetic diversity of R. tanezumi was highest in samples from Jiangsu and Guangdong provinces. Conclusion: The data in this paper confirm the two invasive rodent species from the southeastern coastal region of China may have relied on maritime transport to spread from the southern region of China to the Yangtze River basin. R. tanezumi may then hanve migrated unidirectionally, along the southeastern provinces of China towards the north, while R. norvegicus spread in a complex and multidirectional manner in Hainan, Fujian, Zhejiang and Jiangsu Provinces of the country.

Detection of Trypanosoma lewisi from rodents residing in the densely populated residential regions along the coastal areas of Banyuwangi Sub District, Indonesia.

Extensive attention has been devoted to studies of Trypanosoma lewisi in rodents ever since it became recognised as a zoonotic pathogen known as atypical human trypanosomiasis. Regrettably, although T. lewisi infections of small mammals remain significant public health concerns for humans, there is a lack of comprehensive study in Indonesia. The aim of the study was to detect T. lewisi from rodents residing in the densely populated residential regions along the coastal areas of Banyuwangi Sub District. A total of 169 rodents were captured across three villages of Kampung Mandar, Lateng and Kepatihan, using rat single live traps. After being euthanized and identified, the blood samples were collected from each rodent via cardiac puncture. Subsequently, the samples were subjected to native (direct blood microscopic examination), microscopic blood smear examination, and molecular analyses utilizing TRYP1S-TRYP1R (623 bp) and LEW1S-LEW1R (220 bp). The results demonstrated that two species of rodents were successfully captured: Rattus norvegicus (65.68%) and Rattus tanezumi (34.32%). Based on the native and microscopic blood smear examinations, the prevalence of T. lewisi across three villages was 23.08% and 24.26% for molecular analysis employing both primers, respectively. The highest prevalence was found in Kampung Mandar Village (31.18%), followed by Kepatihan (16.67%) and Lateng Villages (15.71%). Statistical analysis revealed that T. lewisi was more prevalent in R. tanezumi compared to R. norvegicus. In terms of sex, no statistically significant distinction was observed between female and male infected rodents of either species (p > 0.05), indicating both species can serve as a source of T. lewisi for humans in the surveyed villages.

Wild sympatric rodents inhabiting pig farm environments may facilitate the spillover of Enterocytozoon bieneusi from pig farms.

Enterocytozoon bieneusi is a zoonotic pathogen prevalent in mammalian and avian hosts across the globe. Wild small mammals, being abundant worldwide, serve as important sources of zoonotic disease transmission to humans. Here, 227 fecal samples were collected from five rodent and shrew species on 34 pig farms in China to investigate the prevalence and molecular characterization of E. bieneusi. The overall prevalence of E. bieneusi was 17.18% (39/227), with a distribution of 23.53% (32/136) in Rattus tanezumi, 8.62% (5/58) in Rattus norvegicus, and 8.00% (2/25) in Mus musculus. Eight E. bieneusi genotypes were identified, comprising four known genotypes: D (n=8), EbpC (n=8), PigEBITS7 (n=9), and EbpA (n=2), and four novel genotypes: CHPR1 (n=7), CHPR2 (n=1), CHPR3 (n=2), and CHPR4 (n=2). This study is the first to report E. bieneusi in rodents from pig farms in Henan, Shaanxi, and Shanxi Provinces in China. The host range of genotype EbpC was expanded with its first detection in M. musculus and R. tanezumi. All identified E. bieneusi genotypes belong to group 1, raising concerns about these sympatric rodents being reservoirs of zoonotic transmission. Moreover, the widespread distribution of genotype EbpC suggests potential cross-species transmission between sympatric rodents and domestic pigs. Our findings highlight the potential role of sympatric rodents in facilitating the spillover of E. bieneusi from pig farms, which could pose a potential public health threat.

Molecular detection of Cryptosporidium spp. among wild rats in Surabaya, East Java, Indonesia.

Humans and animals who have an acute case of diarrhea can be infected with Cryptosporidium spp. Within the category of water-borne disease, it is a zoonotic disease. The zoonotic disease Cryptosporidium is among the several pathogens carried by wild rats (Rattus spp.). The risk of spreading this disease is rather significant in urban environments because rats are often close to people. This study aims to detect Cryptosporidium spp. infection in wild rats in Surabaya, East Java, Indonesia. Through necropsy, a total of 100 wild rats' intestines were sampled for feces. Microscopic observation of the presence of Cryptosporidium was carried out using the float test with a combination of Ziehl Neelsen (ZN) staining. Molecular detection of Cryptosporidium spp. positive results used the Cryptosporidium oocyst wall protein (COWP) gene with polimerase chain reaction method. The results showed that 69 samples were positive for containing Cryptosporidium spp. oocysts and with ZN staining to confirm the diagnosis, the staining results showed Cryptosporidium spp. oocysts dark pink with a clear cavity inside with a percentage of 95.65% in Rattus norvegicus and 61.03% in Rattus tanezumi. In residential and densely populated environments the percentage of Cryptosporidium spp. amounted to 66.66% and in the market environment amounted to 74.19%. The percentage of Cryptosporidium spp. in the North Surabaya region was 42.85%, South Surabaya 100%, West Surabaya 37.5%, East Surabaya 81.39%, and Central Surabaya 65.38%. Molecular detection of Cryptosporidium spp. positive results were obtained using the COWP gene 550 bp. This study aims to detect Cryptosporidium spp. infection in wild rats in Surabaya, East Java, Indonesia. The high number of cases of cryptosporidiosis in wild rats has the potential to be a reservoir for the spread of the disease. The Cryptosporidium spp can detected with COWP in 550 bp in wild rats in Surabaya, East Java, Indonesia.

Inundation Sewers and Mapping the Prevalence Leptospirosis Throughout Rats in Central Java Province

Leptospirosis is a public health threat in countries with tropical climates, like Indonesia. Incidents in Central Java Province are still found every year and still threaten the local community. The goal of this study is to find out what connection there is between sewer puddles and mice that have found leptospira bacteria that can cause leptospirosis in the Regencies of Klaten, Sukoharjo, Karanganyar, and Boyolali in Central Java Province. This research uses descriptive analysis, a cross-sectional design study, and the Geographic Information System (GIS) to carry out mapping. From the research results, it was found that the rat species that were positive for leptospira bacteria were Rattus norvegicus (31%), Rattus tanezumi (44.8%), and Rattus argentiventer (24.1%). Apart from that, only the sampling area and the presence of puddles in the gutter had significant results with the mouse PCR results with p<0.002 and p<0.03. Due to this, there are still many mice infected with leptospira bacteria in Central Java Province. For this reason, it is hoped that the public can increase awareness to always maintain a clean environment so that mice cannot breed freely. Apart from that, related agencies can carry out more monitoring of areas where leptospirosis is still endemic.

Co-occurrence of ectoparasites on wild rodents in Sipora Island, Mentawai, Indonesia with the zoonotic potential review

Abstract. Mairawita, Mursyid A, Dahelmi, Diniyati F, Lidia D, Putri N, Arifa MM, Jefrial, Maulana RM. 2023. Co-occurrence of ectoparasites on wild rodents in Sipora Island, Mentawai, Indonesia with the zoonotic potential review. Biodiversitas 24: 6369-6376. A complex interaction between human existence and synanthropic rodents can facilitate the spillover of zoonotic diseases. This research provides valuable data regarding Rodentia species distribution, ectoparasites, and the potential for zoonotic transmission. In linked habitats, rodents were collected systematically using 70 live traps over 3 days. A total of 54 Rodentia individuals were assessed, belonging to 7 species: Mus musculus, Rattus tanezumi, R. tiomanicus, R. rattus, R. argentiventer, R. norvegicus, and Leopoldamys siporanus. Additionally, 7 species of ectoparasites (mites, ticks, and fleas) were identified, including Laelaps echidninus, Leptotrombidium delicense, Haemaphysalis longicornis, Ornithonyssus bacoti, Culicoides sp., Hoplopleura pasifica, and Polyplax spinulosa. Various ectoparasites infested all the captured rats. Laelaps echidninus showed the highest prevalence and relative abundance in plantation habitats (81.25% and 68.81) and human dwellings (72.73% and 89.73). Spearman correlation analysis revealed a strong positive correlation between prevalence-abundance of species ectoparasite (?. 0.955; p-value <0.01), while positive correlations between habitat types-prevalence (?. 0.439; p-value <0.01) and habitat types-abundance of species ectoparasite (?. 0.426; p-value <0.01). Negative correlations between ectoparasites species-prevalence (?. -0.273; p-value <0.05) and ectoparasites species-abundance of species ectoparasites (?. -0.309; p-value <0.05). These findings emphasize the need to assess zoonotic risks and take effective control measures in island regions for public health and conservation.

A Report of Neglected Zoonotic Helminth Infections among House Rats in Selected Areas of Metro Manila and Region IV-A CALABARZON, Philippines

Soil-transmitted helminthiasis remains to be a major global health issue predominantly in tropical and sub-tropical regions including the Philippines. People living in poor areas without adequate sanitation are at high risk of contracting these diseases. Rodents and other mammalian species living near humans can serve as potential reservoir hosts and accelerate the spread of these parasitic infections. However, there are only few data and studies on environmental contamination, animal reservoirs, and the zoonotic potential of these parasites. The aim of this study was to determine the faunal diversity of helminths among house rats in selected areas of Metro Manila and CALABARZON, Philippines. This information will serve as baseline data for the development of long-term and effective approaches to prevent and control the zoonotic transmission in the country. A total of 60 house rats were caught and grossly examined. The overall prevalence of soil-transmitted helminth infections was 96.67% (58/60). Of the cases, 51.67% (31/60) were reported in Metro Manila while 45.00% (27/60) were reported in CALABARZON. Capillaria hepatica was the most dominant endoparasite with the highest prevalence and intensity of infection. The four identified helminths namely Capillaria hepatica, Taenia taeniaeformis, Hymenolepis diminuta, and Raillietina spp. transmitted by these Rattus species namely Rattus norvegicus and Rattus tanezumi pose a health risk to the public as they are important reservoirs of zoonotic parasites that are capable of transmitting infection to humans. Therefore, it is necessary to regularly monitor and control rodent populations to reduce the spread of parasites in urban and rural areas.

The male's scent triggered a neural response in females despite ambiguous behavioral response in Asian house rats.

Pheromones and olfactory communication play vital roles in sex recognition and mate choice in rodents. Asian house rats (Rattus tanezumi) (RT) often startle easily, making behavioral measurements difficult to carry out accurately in the laboratory. Here, the behavioral and olfactory preferences of the female RT between males and females were not observed using a conventional two-choice device; we then explored the neuro-immunohistochemical evidence in the brains of RT females. We found that male urine elicited significantly higher c-fos expression in the accessory olfactory system and sex-related brain regions in females than female urine did. On the other hand, the differences of volatile compounds and major urinary proteins (MUPs) in both voided urine and preputial glands (PGs) of the RT were detected using gas chromatography-mass spectrometer, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, isoelectric focusing electrophoresis, and liquid chromatography-electrospray ionization mass spectrometry. We found that PG-derived 1-(4,5-dihydro-2-thiazolyl)-ethanone and total MUPs were more abundant in males versus females, suggesting these sexually divergent components might activate the female's accessory olfactory system. In conclusion, the neuro-immunohistochemical evidence indicated that potential sex pheromones might exist in RT; however, the strength of the chemical signal might be too weak to cause behavioral responses in females.

The Prevalence of Rodents Orientia tsutsugamushi in China During Two Decades: A Systematic Review and Meta-Analysis.

Background: Orientia tsutsugamushi is a zoonotic intracellular pathogen that requires parasitism in eukaryotic cells to reproduce. In recent years, tsutsugamushi disease reported in many places nationwide has crossed the Yangtze River, continuously, spreading to the North China. Now this phenomenon has aroused people's attention. Materials and Methods: In this study, meta-analysis was used to analyze the infection of rodents (vectors) in China, to clarify the transmission rule of O. tsutsugamushi. Results: This study included literature from six databases (PubMed, Web of Science, Science Direct, Wanfang, CNKI, and VIP). A total of 55 articles were included in the study from 610 retrieved articles. The total infection rate of O. tsutsugamushi in rodents was 5.5% (1206/20,620, 95% confidence interval [CI]: 0.0553-0.0617). The prevalence of O. tsutsugamushi in rodents before 2013 (7.73%, 95% CI: 4.11-12.37) was higher than after 2013 (2.11%, 95% CI: 0.64-4.41). O. tsutsugamushi spread among a variety of rodents, among which Rattus losea (13.3%, 95% CI: 4.33-26.26), Rattus tanezumi (5.69%, 95% CI: 1.37-12.72), and Apodemus agrarius (5.32%, 95% CI: 2.26-9.58) infection rate was higher. Kawasaki (8.32%, 95% CI: 1.42-20.17), Karp (7.36%, 95% CI: 2.62-14.22), Kato (2.54%, 95% CI: 0.08-8.28), and Gilliam (2.13%, 95% CI: 0.42-5.09) were the main prevalent genotypes in China. The prevalence of O. tsutsugamushi in rodents was seasonal, increasing gradually in summer (2.39%, 95% CI: 0.46-5.77), peaking in autumn (4.59%, 95% CI: 1.15-10.16), and then declining. The positive rate of immunofluorescence assay (25.07%, 95% CI: 8.44-46.88) was the highest among the detection methods, and it was statistically significant (p < 0.05). Based on the subgroup of geographical factors and climatic factors, the probability of O. tsutsugamushi infection in rodents was the highest when the temperature >19℃ (8.20%, 95% CI: 1.22-20.52), the altitude <100 millimeters (7.23%, 95% CI: 3.45-12.26), the precipitation >700 millimeters (12.22%, 95% CI: 6.45-19.50), and the humidity 60-70% (7.80%, 95% CI: 4.17-12.44). Conclusions: Studies have shown that rodents carrying O. tsutsugamushi are common. People should prevent and control rodents in life and monitor rodents carrying O. tsutsugamushi for a long time.

Molecular detection of Coxiella burnetii and Coxiella species in rats and chickens from poultry farms in North West Province, South Africa.

Coxiella burnetii is a bacterial pathogen that causes query fever and coxiellosis in humans and animals, respectively. There is a scarcity of studies on the prevalence of C. burnetii infections in rats and chickens in South Africa. The aim of this study was to determine the occurrence of C. burnetii in rats and chickens sampled from poultry farms in the North West Province of South Africa. DNA was extracted from rodent kidneys (n=68) and chicken faeces (n=52). Two rodent pest species, namely Rattus rattus and Rattus tanezumi, were identified by analysis of CO1 gene sequences. Detection of C. burnetii was carried out using polymerase chain reaction assays targeting 23S rRNA, 16S rRNA and IS111 markers. C. burnetii was detected in 16.2%, 8.8% and 25% of R. rattus, R. tanezumi and chickens, respectively. The findings in this study demonstrate that rodents and chickens are harbouring C. burnetii at sampled poultry farms. There should be frequent screening for C. burnetii in poultry operations. The likelihood of future transmission between rodents and chickens, including humans, also needs to be investigated.

Genomic diversity of Yersinia pestis from Yunnan Province, China, implies a potential common ancestor as the source of two plague epidemics

Plague, caused by Yersinia pestis, is a zoonotic disease that can reemerge and cause outbreaks following decades of latency in natural plague foci. However, the genetic diversity and spread pattern of Y. pestis during these epidemic-silent cycles remain unclear. In this study, we analyze 356 Y. pestis genomes isolated between 1952 and 2016 in the Yunnan Rattus tanezumi plague focus, China, covering two epidemic-silent cycles. Through high-resolution genomic epidemiological analysis, we find that 96% of Y. pestis genomes belong to phylogroup 1.ORI2 and are subdivided into two sister clades (Sublineage1 and Sublineage2) characterized by different temporal-spatial distributions and genetic diversity. Most of the Sublineage1 strains are isolated from the first epidemic-silent cycle, while Sublineage2 strains are predominantly from the second cycle and revealing a west to east spread. The two sister clades evolved in parallel from a common ancestor and independently lead to two separate epidemics, confirming that the pathogen responsible for the second epidemic following the silent interval is not a descendant of the causative strain of the first epidemic. Our results provide a mechanism for defining epidemic-silent cycles in natural plague foci, which is valuable in the prevention and control of future plague outbreaks.

The Existence of Leptospira interrogans on Rats and The Transmission Potency in Public Areas: School, Traditional Market, and Settlement in Yogyakarta

Leptospirosis is a zoonotic disease caused by bacterial infection, Leptospira interrogans. Indonesia is known for being an endemic country of this disease and Yogyakarta Special Province has become one of the regions with high cases of Leptospirosis. There was lack of information on the L. interrogans prevalence on rats at the public areas, such as school and traditional market. This research was conducted to determine and predict the potential Leptospirosis transmission in public areas, especially in schools, traditional markets,. and the settlement of Yogyakarta. Wild rats were collected from several public places (elementary schools, traditional markets, and Settlement areas) by using single live traps. The rat's blood was centrifuged to obtain the serum. The serum was tested by using immunochromatography of Leptotek Lateral Flow. The collected rats and shrews were euthanized and then identified for the species and the morphological features. Total of 27 rats (67.5%) and shrews 13 (32.5%) were collected. There were six species of collected rats, namely Rattus argentiventer, Rattus norvegicus, Rattus tanezumi, Rattus tiomanicus, and Bandicota bengalensis, while the collected shrew species was Suncus murinus. The rats and shrews from traditional market were negative with L. interrogans, however the positive results was in elementary schools (14.28%), that were from R. norvegicus and S. murinus, moreover the positive infection also showed in the settlements (57.14%), that were from R. argentiventer, R. norvegicus, and R. tiomanicus. These findings indicated that school and settlement must be a concern for the leptospirosis transmission.

Species recognition and the divergences in the chemical and ultrasonic signals between two coexisting Rattus species.

The ability to recognize and differentiate between conspecifics and heterospecifics as well as their signals is critical for the coexistence of closely related species. In the genus Rattus, species are morphologically similar and multiple species often coexist. Here, we investigated the interspecific recognition and signal differentiation of two sympatric rat species, the brown rat (Rattus norvegicus, RN) and the Asian house rat (Rattus tanezumi, RT). In a two-way choice test, both RN and RT females showed a preference for conspecific male rats to heterospecific ones. RT females showed a significant preference for accessible urine of males of same species to those of other species, but not for the inaccessible urine. On the other hand, there were significant differences in the structural characteristics of the ultrasonic vocalization emitted by males of these two rat species. Sodium dodecyl sulphate‒polyacrylamide gel electrophoresis (SDS‒PAGE) and isoelectric focusing electrophoresis unveiled that major urinary proteins (MUPs) in voided urine were more highly expressed in RN males versus RT males. The interspecific differences of urinary volatile compounds were also discussed. In conclusion, female rats had the ability to distinguish between males of either species.

Distribution of rats and endoparasites zoonoses risk in Tandang village, Tembalang District, Semarang City

Rats are rodents that coexist with humans because of the abundant easily available food sources, and aggravated due to the lack of public awareness with environmental hygiene. Apart from being troublesome, rats are also intermediaries for the cause of zoonoses. Initial observations, in Tandang village, there are densely populated areas, many rats of various types were found, including Rattus norvegicus, Rattus tanezumi and possibly other types that cause zoonoses. This study aims to examine the distribution of rats and their endoparasites in the Tandang village. The research method is analytical descriptive research. Traps were set at several points around dense settlements and markets. Data obtained by conducting random sampling. From the results of detaintment, 104 rats were obtained, consisting of 5 species namely Rattus norvegicus, Rattus tanezumi, Rattus exulans, Bandicota indica. Mus musculus. Endoparasites found in intestinal organs in the form of the tapeworm Hymenolephis sp., Trichuris trichiura worm eggs, Hymenolepis sp. The distribution of rats was found in dense residential areas, with 27 rats (22.21%) Rattus norvegicus, and 21 rats (20.19%) compared to their distribution in the market. The eggs of these parasitic worms are known to cause infection to humans through objects that encounterd with soil, sewage, etc. and are eventually swallowed. Symptoms experienced when infected include diarrhea, abdominal pain, constipation, and anorexia.

Identifikasi Keberadaan Bakteri Leptospira di Daerah Endemis Leptospirosis (Studi di Dukuh Kalitengah Kecamatan Wedi Kabupaten Klaten)

Background: Several regions in Indonesia are classified as leptospirosis endemic including Klaten Regency, which ranked 2nd highest case of leptospirosis in Central Java in 2018. Leptospirosis in human was transmitted by animals infected by the Leptospira bacteria, which rat was the main reservoir. This study aimed to identify rat reservoir to the existence of Leptospira bacteria in endemic areas.Methods: This study was an observational survey with cross sectional approach. The sample was rats caught by traps installed for 6 days in Dukuh Kalitengah, Kalitengah Village, Wedi Subdistrict, Klaten Regency in July 2019. The rats were identified and dissected to take their kidneys for laboratory testing using the Polymerase Chain Reaction (PCR) test to identity the existence of Leptospira bacteria.Result: The result showed that there were 17 rats and 6 Suncus murinus caught in 6 days and their species were Mus musculus (23.5%), Rattus tanezumi (41.2%), Rattus norvegicus (35.3%). The results of PCR test found 2 positive samples of Leptospira bacteria in Rattus tanezumi. Rattus tanezumi's habitat was close with humans in settlement areas where it can be a source of Leptospira infection and can spread to humans and other environments.Conclusion : The people in Dukuh Kalitengah are recommended to maintain the hygiene of their environment and improve their house’s sanitation so it not become nest and breeding grounds and also reduce the existence of rats.

JUMLAH TIKUS TERTANGKAP MENGGUNAKAN UMPAN IKAN ASIN, KELAPA BAKAR, DAN GORENGAN

Mechanical rat control usually uses traps, and bait is an important factor in successful rat catching. The aim of this study was to describe the diversity of species and sex of rats, as well as to measure the differences in the effectiveness of using salted fish, roastedcoconut and fried foods on the number of rats caught at Kalimas Terminal, Tanjung Perak Port, Surabaya.This research is a quasi-experimental research with a Posttest Only Design research design and was conducted at Kalimas Terminal, Tanjung Perak Port, Surabaya. The variables in this study were the type of bait used, namely salted fish, grilled and fried coconut and the number of rats caught. The tools used were 150 single live traps, each of which 50 traps were baited with salted fish, roasted coconut and fried foods. The ratscaught were identified for their type, sex and number. Species and sex were analyzed using a frequency distribution table, then an ANOVA test with α of 5% was used to analyze differences in the number of rats based on the type of bait installed.The rat species caught were Rattus norvegicus with 57 individuals (15 males and 42 females) and Rattus tanezumi 17 individuals (6 males and 11 females). The number of rats that entered the trap using salted fish bait was 41 tails, 18 rats used roasted coconut bait, and 15 rats used fried bait. There is a difference in the use of salted fish, roasted coconut and fried food on the number of rats caught at the Kalimas Port of Tanjung Perak, Surabaya(p-value = 0.001).Salted fish is the most effective bait compared to roasted and fried coconut. Its use can be replaced with fried bait periodically if the trap success drops drastically.

Infestation of Oriental House Rat (Rattus tanezumi) with Chigger Mites Varies along Environmental Gradients across Five Provincial Regions of Southwest China.

Chigger mites are the exclusive vector of scrub typhus. Based on field investigations of 91 survey sites in 5 provincial regions of Southwest China, this paper reported variations of chigger infestation on the oriental house rat (Rattus tanezumi) along various environmental gradients. A total of 149 chigger species were identified from 2919 R. tanezumi in the 5 provincial regions, and Leptotrombidium deliense (a major vector of scrub typhus in China) was the first dominant chigger species, followed by Ascoschoengastia indica and Walchia ewingi. Rattus tanezumi had a stable overall prevalence (PM = 21.10%), mean abundance (MA = 7.01), and mean intensity (MI = 33.20) of chiggers with the same dominant mites in the whole Southwest China in comparison with a previous report in Yunnan Province, but chigger infestations on R. tanezumi varied along different environmental gradients. Rattus tanezumi in mountainous landscape had a higher infestation load of chiggers with higher species diversity than in flatland landscape. The infestation was higher at lower altitudes and latitudes. A high intensity of vegetation coverage was associated with high infestations. The results reflect the environmental heterogeneity of chiggers on the same host species. Warm climate and high relative humidity are beneficial to chigger infestation on R. tanezumi.

Seroprevalence of scrub typhus and other rickettsial diseases among the household rodents of Mizoram, North-East India.

In the last decade, scrub typhus, a zoonotic disease has emerged as a major health concern in Mizoram, a North-East Indian state that shares international borders with Myanmar and Bangladesh. Mizoram is a biodiversity hotspot and >85% of the state is under forest cover, which provides an ideal ecological niche for the rodents and mites to transmit scrub typhus and other rickettsial infections. Using the Weil-Felix test, a serosurvey of household rodents from 41 villages spread across all the 11 districts in Mizoram was undertaken to gather important insights on their role in disease transmission. Furthermore, the chigger and flea indexes were calculated from the captured rodents. The 163 rodents captured belonged to five species; the highest numbers were from Rattus tanezumi (87), followed by Rattus rattus (41), Mus musculus (17), Suncus murinus (16), and Bandicota bengalensis (2). The rickettsial seropositivity of the captured rodents was 66.26% (108 out of 163 were positive). Among the 163 rodents, sera of 75 (46.01%), 61 (37.42%), and 73 (44.78%) were reactive to OXK, OX19, and OX2 antigens, respectively. The chigger and flea index were 17.92 and 0.16, respectively. Overall, the study has given important insights into the risk of multiple rickettsial infections that household rodents could transmit in Mizoram. These findings indicate the need for the urgent implementation of effective rodent control strategies in Mizoram.