OBJECTIVETo explore the polymorphism in circumsporozoite protein of Plasmodium vivax before malaria was eliminated in Hainan island.

METHODSPCR amplification, sequencing, and alignment methodologies were conducted and phylogenetic tree constructed.

RESULTSFrom all the cases, 19 of them belonged to two types, with 18 as VK210 type and 1 as VK247 type. VK210 type could be divided into seven kinds of subtypes but VK247 had only one type. Ratio of tropical strain with temperate stain in VK210 type was explored between the two stages:control or elimination. Phylogenetic tree was constructed by amino acid sequencing which clearly manifested that VK210 type and VK247 type belonged to different clusters.

CONCLUSIONCompared the proportion of two types in the control stage, there was no significant difference seen in the stage of elimination.

China ; epidemiology ; Genotype ; Humans ; Malaria, Vivax ; epidemiology ; prevention & control ; Plasmodium vivax ; classification ; genetics ; isolation & purification ; Polymorphism, Genetic ; Spores, Protozoan ; genetics

The annual incidence of Plasmodium vivax malaria that reemerged in the Republic of Korea (ROK) in 1993 increased annually, reaching 4,142 cases in 2000, decreased to 864 cases in 2004, and once again increased to reach more than 2,000 cases by 2007. Early after reemergence, more than two-thirds of the total annual cases were reported among military personnel. However, subsequently, the proportion of civilian cases increased consistently, reaching over 60% in 2006. P. vivax malaria has mainly occurred in the areas adjacent to the Demilitarized Zone, which strongly suggests that malaria situation in ROK has been directly influenced by infected mosquitoes originating from the Democratic People's Republic of Korea (DPRK). Besides the direct influence from DPRK, local transmission within ROK was also likely. P. vivax malaria in ROK exhibited a typical unstable pattern with a unimodal peak from June through September. Chemoprophylaxis with hydroxychloroquine (HCQ) and primaquine, which was expanded from approximately 16,000 soldiers in 1997 to 200,000 soldiers in 2005, contributed to the reduction in number of cases among military personnel. However, the efficacy of the mass chemoprophylaxis has been hampered by poor compliance. Since 2000, many prophylactic failure cases due to resistance to the HCQ prophylactic regimen have been reported and 2 cases of chloroquine (CQ)-resistant P. vivax were reported, representing the first-known cases of CQ-resistant P. vivax from a temperate region of Asia. Continuous surveillance and monitoring are warranted to prevent further expansion of CQ-resistant P. vivax in ROK.
Antimalarials/administration & dosage ; Chemoprevention ; *Disease Outbreaks ; Drug Resistance ; Humans ; Malaria, Vivax/drug therapy/*epidemiology/parasitology/prevention & control ; Military Personnel ; Plasmodium vivax/drug effects/*physiology ; Republic of Korea/epidemiology

Changing patterns of the reemerging Plasmodium vivax malaria in the Republic of Korea (South Korea) during the period 1993 to 2005 are briefly analyzed with emphasis on the control measures used and the effects of meteorological and entomological factors. Data were obtained from the Communicable Diseases Monthly Reports published by the Korea Center for Disease Control and Prevention, and webpages of World Health Organization and United Nations. Meteorological data of Kangwon-do (Province) were obtained from local weather stations. After its first reemergence in 1993, the prevalence of malaria increased exponentially, peaking in 2000, and then decreased. In total, 21,419 cases were reported between 1993 and 2005 in South Korea. In North Korea, a total of 916,225 cases were reported between 1999 and 2004. The occurrence of malaria in high risk areas of South Korea was significantly (P<0.05) correlated with the mosquito population but not with temperature and rainfall. Control programs, including early case detection and treatment, mass chemoprophylaxis of soldiers, and international financial aids to North Korea for malaria control have been instituted. The situation of the reemerging vivax malaria in the Republic of Korea is remarkably improving during the recent years, at least in part, due to the control activities undertaken in South and North Korea.
Seasons ; Plasmodium vivax/drug effects ; Military Personnel/statistics & numerical data ; Malaria, Vivax/*epidemiology/parasitology/*prevention & control ; Korea/epidemiology ; Incidence ; Humans ; Disease Outbreaks/*prevention & control ; Communicable Diseases, Emerging/*epidemiology/parasitology/*prevention & control ; Chloroquine/administration & dosage ; Antimalarials/administration & dosage ; Anopheles/parasitology ; Animals

INTRODUCTIONThe objective of the study was to determine the trend of malaria, the epidemiological characteristics, the frequency of local transmission and the preventive and control measures taken.

MATERIALS AND METHODSWe analysed the epidemiological records of all reported malaria cases maintained by the Communicable Diseases Division, Ministry of Health, from 1983 to 2007 and the Anopheles vector surveillance data collected by the National Environment Agency during the same period.

RESULTSThe annual incidence of reported malaria ranged from 2.9 to 11.1 per 100,000 population, with a sharp decline observed after 1997. There were 38 deaths, 92.1% due to falciparum malaria and 7.9% due to vivax malaria. Of the reported cases, 91.4% to 98.3% were imported, with about 90% originating from Southeast Asia and the Indian subcontinent. Among the various population groups with imported malaria, the proportion of cases involving work permit/employment pass holders had increased, while that of local residents had decreased. Between 74.8% and 95.1% of the local residents with imported malaria did not take personal chemoprophylaxis when they travelled overseas. Despite the extremely low Anopheles vector population, a total of 29 local outbreaks involving 196 cases occurred. Most of the larger outbreaks could be traced to foreign workers with imported relapsing vivax malaria and who did not seek medical treatment early. One of the outbreaks of 3 cases in 2007 was caused by Plasmodium knowlesi, a newly recognised simian malaria which was probably acquired in a forested area where long-tail macaques had been sighted.

CONCLUSIONSSingapore remains both vulnerable and receptive to the reintroduction of malaria and a high level of vigilance should be maintained indefinitely to prevent the re-establishment of endemicity. Medical practitioners should highlight the risk of malaria to travellers visiting endemic areas and also consider the possibility of simian malaria in a patient who has no recent travel history and presenting with daily fever spikes and with malaria parasite morphologically similar to that of P. malariae.

Adolescent ; Adult ; Animals ; Anopheles ; Child ; Child, Preschool ; Disease Outbreaks ; Emigrants and Immigrants ; Female ; Humans ; Incidence ; Infant ; Infant, Newborn ; Insect Vectors ; Malaria ; epidemiology ; prevention & control ; transmission ; Malaria, Falciparum ; epidemiology ; prevention & control ; transmission ; Malaria, Vivax ; epidemiology ; prevention & control ; transmission ; Male ; Middle Aged ; Plasmodium knowlesi ; Plasmodium malariae ; Population Surveillance ; Recurrence ; Retrospective Studies ; Risk Factors ; Singapore ; epidemiology ; Travel ; Young Adult

As the last part of a program to survey the extent of malaria transmission in the Papua New Guinea highlands, a series of rapid malaria surveys were conducted in 2003-2004 and 2005 in different parts of Southern Highlands Province. Malaria was found to be highly endemic in Lake Kutubu (prevalence rate (PR): 17-33%), moderate to highly endemic in Erave (PR: 10-31%) and moderately endemic in low-lying parts (< 1500 m) of Poroma and Kagua (PR: 12-17%), but was rare or absent elsewhere. A reported malaria epidemic prior to the 2004 surveys could be confirmed for the Poroma (PR: 26%) but not for the lower Kagua area. In Kutubu/Erave Plasmodium falciparum was the most common cause of infection (42%), followed by P. vivax (39%) and P. malariae (16%). In other areas most infections were due to P. vivax (63%). Most infections were of low density (72% < 500/ microl) and not associated with febrile illness. Overall, malaria was only a significant source of febrile illness when prevalence rates rose above 10%, or in epidemics. However, concurrent parasitaemia led to a significant reduction in haemoglobin (Hb) level (1.2 g/dl, CI95: [1.1-1.4.], p < 0.001) and population mean Hb levels were strongly correlated with overall prevalence of malarial infections (r = -0.79, p < 0.001). Based on the survey results, areas of different malaria epidemiology are delineated and options for control in each area are discussed.
Adolescent ; Adult ; Antimalarials/therapeutic use ; Child ; Child, Preschool ; Endemic Diseases ; *Epidemics ; Female ; Geography, Medical ; Humans ; Malaria/drug therapy/*epidemiology/prevention & control ; Malaria, Falciparum/drug therapy/epidemiology/prevention & control ; Malaria, Vivax/drug therapy/epidemiology/prevention & control ; Male ; Mosquito Nets/utilization ; Papua New Guinea/epidemiology ; Prevalence ; Young Adult

OBJECTIVETo establish a minimum medical geographic information systems (GIS) database as a spatial decision supporting system (SDSS), and to use the database into public health practice in China.

METHODSSpatial data collected from different sources were standardized as decimal degree format, including: (1) satellite images covering areas of China; (2) digital maps of China in vector files; (3) diseases database and relevant models.

RESULTSNecessary satellite images for the database have been collected from NOAA AVHRR, Landsat TM, etc., including the normalized difference vegetation index (NDVI) images from AVHRR, earth surface temperature images from AVHRR, GTOPO30 DEM images from USGS and landuse images from USGS. The digital vector files for GIS analysis were collected including political (county, provinces, country) boundaries file, environmental (drainage, land cover, soil type) vector file, population data and climate data; Data on diseases mainly generated from survey or case reporting. Relevant models on transmission of Schistosoma japonicum and Plasmodium vivax, and models of Oncomelania hupensis and Anophores sinansis were developed, and the relevant environmental factors related to incidence of cancers were mapped, to test and verify those database.

CONCLUSIONThe database unified the data from different sources for users. Minimum medical data included in the database could be used in the practice of public health. It is expected that this database be used in a wider range.

Animals ; Anopheles ; parasitology ; China ; epidemiology ; Databases, Factual ; Disease Reservoirs ; Disease Vectors ; Ecology ; Geographic Information Systems ; Humans ; Malaria ; epidemiology ; prevention & control ; transmission ; Plasmodium vivax ; Satellite Communications ; Schistosomiasis japonica ; epidemiology ; prevention & control ; transmission ; Snails ; parasitology

Vivax malaria was endemic on the Korean peninsula for many centuries until the late 1970's when the Republic of Korea (ROK) was declared "malaria free". Since its re-emergence in 1993, the number of malaria cases in the military increased exponentially through 2000 near the demilitarized zone. Chemoprophylaxis with chloroquine and primaquine has been used in the ROK Army since 1997 in an attempt to reduce the number of the malaria cases throughout the ROK. Data show that chemoprophylaxis contributed, in part, to the decrease in the number of malaria cases among military personnel. However, mass chemoprophylaxis on a large scale in the ROK Army is unprecedented and extensive supervision and monitoring is warranted to determine its effectiveness and to monitor the appearance of chloroquine tolerant/resistant strains of Plasmodium vivax.
Antimalarials/therapeutic use ; Chemoprevention/methods/statistics and numerical data ; Chloroquine/*therapeutic use ; Disease Outbreaks/*prevention and control/*statistics and numerical data ; Humans ; Incidence ; Korea/epidemiology ; Malaria, Vivax/*epidemiology/*prevention and control ; Military Personnel/*statistics and numerical data ; Outcome Assessment (Health Care) ; Prevalence ; Primaquine/*therapeutic use ; Research Support, Non-U.S. Gov't ; Risk Assessment/methods ; Risk Factors ; Treatment Outcome