Your search found 12 records
1 IIMI. SLFO. 1994. Monitoring resources use change. SCOR Monitor, 1(2/3):10-11.
(Location: IWMI-HQ Call no: P 3725 Record No: H016238)
(Location: IWMI HQ Call no: IIMI 631.7.5 G744 AME Record No: H09224)
A 13-mo survey of immature anopheline mosquitoes breeding in surface water habitats was done at Mahameegaswewa village within the Huruluwewa watershed in north central Sri Lanka as part of a multidisciplinary study on malaria epidemiology. The watershed is representative of the ancient small tank-based irrigation network that still forms an important component of the rice production system in the low elevation dry zone. In total, 3,818 immatures representing 12 species were obtained from 2,940 samples taken from 5 larval habitats within the village ecosystem. Anopheles varuna Iyengar and An. culicifacies Giles were the most abundant species collected. Peak abundance in both species occurred in August-October. Anopheles barbirostris Van der Wulp and An. peditaeniatus Leicester also were abundant, but neither these nor the other anophelines attained comparable abundance to An. varuna and An. culicifacies. A clear progression in breeding habitat use from stream bed to tank bed and drainage area pools was seen in An. culicifacies during the premonsoon period. Environmental management measures to reduce or modify these habitats could potentially decrease malaria transmission.
(Location: IWMI-HQ Call no: IWMI 631.7.5 G744 KON Record No: H09225)
(Location: IWMI-HQ Call no: IIMI 631.7.5 G744 KON Record No: H09226)
5 Amerasinghe, F. P.; Konradsen, F.; Amerasinghe, P. H.; van der Hoek, W.; Fonseka, K. T.; Perera, D. 1998. Malaria vectors and transmission dynamics in a "purana" village ecosystem. [Abstract only]. In Careem, M. A.; Mendis, B. R. R. N.; Nelson, M. D. (Eds.). Proceedings and abstracts of the Annual Research Sessions, University of Peradeniya, Sri Lanka, 7 November 1998. pp.22.
(Location: IWMI-HQ Call no: IWMI 631.7.5 G744 AME Record No: H023817)
(Location: IWMI-HQ Call no: IWMI 616.9362 G744 AME Record No: H024197)
Malaria transmission by anopheline mosquitoes was studied in a traditional tank-irrigation-based rice-producing village in the malaria-endemic low country dry zone of northcentral Sri Lanka during the period August 1994-February 1997. Adult mosquitoes were collected from human and bovid bait catches, bovid-baited trap huts, indoor catches, and pit traps. Mosquito head-thoraces were tested for the presence of Plasmodium falciparum and P. vivax, and blood-engorged abdomens for the presence of human blood by ELISAs. House surveys were done at two-day intervals to record cases of blood film-confirmed malaria among the villagers. A total of 7,823 female anophelines representing 14 species were collected. Trends in anopheline abundance were significantly correlated with rainfall of the preceding month in An. annularis, An. barbirostris, An. subpictus, An. vagus, and An. varuna, but were not significant in An. culicifacies and An. peditaeniatus. Malaria parasite infections were seen in seven mosquito species, with 75% of the positive mosquitoes containing P. falciparum and 25% P. vivax. Polymorph PV247 was recorded from a vector (i.e., An. varuna) for the first time in Sri Lanka. Computations of mean number of infective vector (MIV) rates using abundance, circumsporozoite (CS) protein rate, and human blood index (HBI) showed the highest rate in An. culicifacies. A malaria outbreak occurred from October 1994 to January 1995 in which 45.5% of village residents experienced at least a single disease episode. Thereafter, malaria incidence remained low. Anopheles culicifacies abundance lagged by one month correlated positively with monthly malaria incidence during the outbreak period, and although this species ranked fifth in terms of abundance, infection was associated with a high MIV rate due to a high CS protein rate and HBI. Abundance trends in other species did not correlate significantly with malaria. It was concluded that An. culicifacies was epidemiologically the most important vector in the study area.
7 Senaka Arachchi, R. B. 1998. Drought and household coping strategies among peasant communities in the Dry Zone of Sri Lanka. In Twigg, J.; Bhatt, M. R. (Eds.),Understanding vulnerability: South Asian perspective. Surrey, U.K.: Biddles & Co. pp.27-46.
(Location: IWMI-HQ Call no: IIMI 338.14 G744 SEN, 363.34 G570 TWI Record No: H024579)
8 Twigg, J.; Bhatt, M. R. (Eds.) 1998. Understanding vulnerability: South Asian perspectives. London, UK: Intermediate Technology Publications, on behalf of Duryog Nivaran. vii, 84p.
(Location: IWMI-HQ Call no: 363.34 G570 TWI Record No: H026831)
9 Somaratne, P. G. 1997. Development of organizations and institutions in Huruluwewa: Evaluation report. Unpublished report, on monitoring and evaluation of the organizational and institutional development aspects of the SCOR Project. 115p. + annexes.
(Location: IWMI-HQ Call no: IWMI 631.7.3 G744 SOM Record No: H028726)
10 Turner, A.; Ganewatte, P.; Wickremasinghe, G.; Herath, A. 1999. Final evaluation of the Shared Control of Natural Resources Sub-Project, Sri Lanka - Final report. Report submitted to USAID by ARD Inc., Burlington, VT, USA. Contract No. LAG-1-00-98-00031-00. v.p.
(Location: IWMI-HQ Call no: IIMI 333.91 G744 TUR Record No: H029014)
(Location: IWMI HQ Call no: IIMI 631.7.8 G744 IIM Record No: H020853)
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(Location: IWMI HQ Call no: IWMI 614.532 G744 AME Record No: H041472)
Malaria risk factor studies have traditionally used microscopy readings of blood slides as the measure of malaria infection in humans, although alternatives are available. There is the need for an assessment of how the use of these alternative diagnostic approaches will influence the efficiency and significance of epidemiological studies. In an area of Sri Lanka with known risk factors for malaria, two cross-sectional surveys were done at the start and at the peak of transmission season. Microscopy was compared with enzyme-linked immunosorbent assays (ELISA) and polymerase chain reaction (PCR). The major risk factor in this area was the location of houses relative to confirmed vector breeding sites. At the peak of the transmission season, the results pointed in the same direction, irrespective of the diagnostic method used. However, the importance of distance from the breeding site was not statistically significant when microscopy was used, which can be explained by the lower prevalence of microscopy positivity in comparison to the prevalence of ELISAand PCR-positivity. This study suggests that in low-transmission areas, such as Sri Lanka, smaller sample sizes can be used for epidemiological research studies using PCR instead of microscopy to estimate parasite prevalence. This efficiency gain has to be weighed against the higher cost and complexity of the PCR. PCR cannot replace microscopy as the standard diagnostic procedure at the field level. ELISA is not directly comparable with microscopy and PCR but it can also be a useful tool in malaria epidemiological studies. This study indicates that cross-sectional surveys are only efficient if they take place during peak transmission season. Cross sectional surveys currently implemented by the Sri Lankan government in response to local malaria outbreaks can form the basis for valid epidemiological studies and be used for the generation of malaria risk maps if samples were also analyzed using PCR.
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