A cytotoxic T lymphocyte (CTL) response to dengue virus-infected target cells is described. Effector cells were generated in an in vitro secondary culture and appeared to be T cells possessing both the Lyt 1.1 and Lyt 2.1 surface antigens. A stronger CTL response was noted with the H-2k haplotype compared to H-2d, and H-2 compatibility was required between CTL and target cells. CTL generated showed some cross-reactivity with target cells infected with Japanese encephalitis virus (JEV), another flavivirus, but not with target cells infected with an alphavirus, Sindbis. The significance and importance of these findings are discussed.
Thirty isolations of Tembusu virus and four of Sindbis virus were obtained from approximately 280 000 mosquitoes collected between October 1968 and February 1970 in Sarawak, particularly from K. Tijirak, a Land Dyak village 19 miles South of Kuching. Twenty-two isolations of Tembusu virus and two of Sindbis virus were from Culex tritaeniorhynchus; two of Tembusu virus and two of Sindbis virus came from Culex gelidus. Tembusu virus was active throughout the year at K. Tijirak, the highest infection rates in C. tritaeniorhynchus being in January-March and May-August, when the C. tritaeniorhynchus population was declining and ageing. These results confirm that C. tritaeniorhynchus is the principal arthopod host of Tembusu virus in Sarawak. Antibody studies suggest that birds, particularly domestic fowl, are probably vertebrate maintenance hosts of Tembusu and Sindbis viruses in Sarawak.
This data article informs about Chiropteran diversity, new records, ecosystem services and possible pathogen carriers in fragmented forests (sub-divided by utility corridors, man-made structures, untouched and secondary plantations) within districts Setiu (Setiu Research Station), Hulu Terengganu (Saok and Lasir waterfalls) and Besut (Gunung Tebu Forest Reserve) of state Terengganu, Peninsular Malaysia. These bats were captured using harp traps and mist nets that were set 10 m apart across flyways, streams and less cluttered trees in the 50 m × 50 m transect zones (identified at each site). All animals were distinguished by morphology and gender before their release at the site of capture. The data comprise of five bat family groups Hipposideridae, Megadermatidae, Pteropodidae, Rhinolophidae and Vespertilionidae. It is interesting to note that untouched Saok Waterfalls is home to wide variety of bats listed (68.8%), followed by secondary forests of Gunung Tebu Forest Reserve (24.8%), untouched Lasir Waterfalls (4.8%) and lastly, Setiu Research Station as least favored (1.6%). Chiroptera like Cynopterus brachyotis (n = 23, 37.7%), Hipposideros bicolor (n = 6, 9.8%) and Scotophilus kuhli (n = 6, 9.8%) were most dominant in the checklist whereas Hipposideros armiger, Murina suilla and Scotophilus kuhlii are new data records in the fragmented forests of Terengganu. The data were interpret into Shannon, Simpson, Margalef, Menhinik and Evenness indices to individually or collectively distinguish chiropteran variety in Terengganu State whereas weight-forearm length (W/FA) informs about chiropteran Body Condition Index (-0.25 to 0.25). The function of bats were also identified to distinguish service providers (pollination and forests regeneration) and zoonotic pathogen carriers (in particular to Leptospira bacteria, Nipah virus and Sindbis virus).
Plaque reduction neutralization tests, using five group A arboviruses (chikungunya, Ross River, Getah, Bebaru and Sindbis), were done on sera from human populations in 44 Southeast Asia and Pacific island localities. Specificity of the plaque neutralization test was determined by examining convalescent sera from patients with known alphavirus infections. Chikungunya-specific neutralizing antibodies were demonstrated in sera of persons living in South Vietnam, Northern Malaysia, Indonesia (Kalimantan and Sulawesi), as well as Luzon, Marinduque, Cebu and Mindanao islands in the Philippines. Evidence of Ross River virus infection was found among populations living in West New Guinea and Papua New Guinea mainland, the Bismark Archipelago, Rossel Island and the Solomon Islands. There appeared to be no geographic overlap in the distribution of chikungunya and Ross River viruses, with the separation in their distribution corresponding with Weber's line in the Pacific. Sindbis neutralizing antibodies were found in 7 of 21 populations sampled, but in general the prevalence of infection was low. Four sera, from Vietnam, Malaysia and Mindanao gave monospecific reactions with Getah virus. No evidence of specific Bebaru virus infection was detected. The epidemiology of these five alphaviruses in Southeast Asia and the Pacific islands is discussed.
A survey of the activity of three alphaviruses (Sindbis, getah and chikungunya) in Peninsular Malaysia was conducted between 1962 and 1970. Serum samples were examined from 3,917 vertebrates representing a wide variety of wild and domestic animals throughout the peninsula for hemagglutination-inhibiting and neutralizing antibodies. A total of 548,939 mosquitoes were collected from different habitats, including jungle, rural, suburban and urban areas, and the majority of the females taken were examined for the presence of virus. Two strains of Sindbis virus and one strain of getah virus were isolated from pools of Culex mosquitoes collected in and around domestic animal shelters. Analysis of the serological results indicated that, 1) getah virus is associated principally with large domestic animals, particularly swine, 2) Sindbis virus is associated with large domestic animals and birds, especially domestic ducks, and 3) chikungunya virus, which has not yet been isolated in Malaysia, appeared to be present at a very low level of activity, probably with wild monkeys as the vertebrate hosts.
A serum survey of several characteristic groups of humans in urban, rural, and forested areas of Peninsular Malaysia for evidence of infection with three alphaviruses (Sindbis, getah, and chikungunya) was made on 4384 specimens collected between 1965 and 1969. Analysis of the serological results indicated that 1) persons residing in predominantly rural and forested areas have higher frequencies of specific alphavirus antibody of all three viruses than persons residing in urban areas, 2) human infection with chikungunya virus appears to be at a low level of activity but is widespread, although more common and recent in the northern part of the country, and 3) Sindbis and getah viruses probably do not represent a threat to the public health, but chikungunya virus remains a potential menance and may be responsible for future epidemics transmitted by A. aegypti and A. albopictus mosquitoes.