Tatiyanuch Chamsai

Seasonal abundance and potential of Japanese encephalitis virus infection in mosquitoes at the nesting colony of ardeid birds, Thailand

OBJECTIVE To investigate the abundance and seasonal dynamics of mosquitoes, and to detect Japanese encephalitis virus (JEV) in these mosquitoes at the nesting colony of ardeid birds. METHODS Mosquitoes were collected bimonthly from July 2009 to May 2010 by Centers for Disease Control. Light traps and dry ice, as a source of CO2, were employed to attract mosquitoes. Mosquitoes were first identified, pooled into groups of upto 50 mosquitoes by species, and tested for JEV infection by viral isolation and reverse transcriptase polymerase chain reaction. RESULTS A total of 20 370 mosquitoes comprising 14 species in five genera were collected. The five most abundant mosquito species collected were Culex tritaeniorhynchus (95.46%), Culex vishnui (2.68%), Culex gelidus (0.72%), Anopheles peditaeniatus (0.58%) and Culex quinquefasciatus (0.22%). Mosquito peak densities were observed in July. All of 416 mosquito pools were negative for JEV. CONCLUSIONS This study provides new information about mosquito species and status of JEV infection in mosquitoes in Thailand. Further study should be done to continue a close survey for the presence of this virus in the ardeid birds.

Mosquito distribution and West Nile virus infection in zoos and in important sites of migratory and resident birds, Thailand

Objective To investigate the distribution of mosquito species in the zoos and in important sites of migratory and resident birds and evaluate West Nile virus (WNV) infection in mosquito species.

Detection and characterization of Chlamydophila psittaci in asymptomatic feral pigeons (Columba livia domestica) in central Thailand.

OBJECTIVE To detect and characterize Chlamydophila psittaci (C. psittaci) in asymptomatic feral pigeons in central Thailand. METHODS A total 814 swabs from the trachea and cloacae of 407 non-clinical feral pigeons in central Thailand were collected and tested for the presence of C. psittaci. RESULTS A 10.8% of feral pigeons in the sample group were positive as determined by nested PCR primer specific to C. psittaci. The outer membrane protein A (ompA) gene of positive samples exhibited amino acid identity of C. psittaci ranging from 71 to 100% and were grouped in genotype B. Exceptionally, BF1676-56 isolate was closely related to Chlamydia avium with 99% identification of the 16S ribosomal (r) RNA gene. CONCLUSIONS This is the first report on C. psittaci isolated from asymptomatic feral pigeons in Thailand, which provides knowledge for the disease status in pigeon populations in Thailand.

Stomoxyini fly fauna of the Khao Yai National Park, Thailand

Objective To determine species diversity, relative population abundance and diurnal activity of the Stomoxyini flies at the Khao Yai National Park.

Potentially Pathogenic Leptospira Species Isolated from a Waterfall in Thailand

We collected water and soil samples from a waterfall in Thailand to investigate the presence of potentially pathogenic Leptospira. Isolation of Leptospira from all the 17 environmental samples was successful. Based on 16S rRNA gene sequence analysis, a diverse group of Leptospira species was recovered from waterfall samples including 2 pathogenic species (Leptospira alstonii [5/17, 29%] and Leptospira kmetyi [1/17, 6%]); 1 intermediate species (Leptospira wolffii [9/17, 53%]); and 2 non-pathogenic species (Leptospira meyeri [1/17, 6%] and Leptospira idonii [1/17, 6%]). The high prevalence of pathogenic and intermediate Leptospira indicates that a waterfall may serve as a natural reservoir of possible pathogens of leptospirosis.

A LONG-TERM SEROSURVEY OF AVIAN INFLUENZA H5 AMONG WILD BIRDS IN NAKHON SAWAN PROVINCE, THAILAND

Abstract:  An outbreak of HPAIV H5N1 in Nakhon Sawan province, Thailand, in 2004 caused sporadic deaths of Asian openbill storks (Anastomus oscitans). An investigation was undertaken to determine if this virus occurs and circulates in wild birds in Nakhon Sawan province. Following the outbreak, a widespread serosurvey was conducted using the hemagglutination inhibition assay and microneutralization assay to detect antibodies against AIV H5. From 2007 to 2014, blood was collected from a total of 753 wild birds, representing 10 orders and 44 species. The results reveal that 10 serum samples were positive for AIV H5 antibodies. These seropositive results, found in the orders Ciconiiformes and Anseriformes, demonstrate that waterfowl serve as a reservoir host of AIV. Moreover, the seroprevalences in streak-eared bulbul showed habitat sharing with waterfowl or duck.