SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Despite the need to feed growing populations in Asia, controversy over genetically modified foods is putting a damper on efforts to develop and test new crops. The signs of opposition are scattered and vary from country to country. But they are enough to be worrisome to the region's leaders.
North American strains of Aedes albopictus, an Asian mosquito recently introduced into the Western Hemisphere, exhibit photoperiodic sensitivity and cold-hardiness characteristics similar to strains originating from temperate zone Asia. Trade statistics for used tire imports, the most likely mode of introduction, also indicate a north Asian origin. Aedes albopictus, an important vector of dengue and a potential vector of many other arboviral diseases, may therefore have the capability of infesting much of temperate North America.
As part of the SENTRY antimicrobial surveillance program, we examined the prevalence rates, types, and antibiograms of oxacillin-resistant Staphylococcus aureus from hospitalized patients from 17 institutions in eight countries in Asia-Pacific and South Africa (APAC). From April 1998 to December 1999, a total of 1,711 isolates of S. aureus (814 from blood, 392 from the respiratory tract, 467 from skin and skin structures, and 38 from urine) were collected from hospitalized patients within the APAC region. Multidrug-resistant oxacillin-resistant S. aureus (MORSA) isolates, defined as strains with three or more resistances to drug classes other than beta-lactams, were the most common type of oxacillin-resistant S. aureus (ORSA). They were the most frequently identified pathogen in wound infections and were common in bloodstream and lower respiratory tract infections. In all contributing institutions combined, more than 45% (range, 4 to 74%) of S. aureus isolates were oxacillin resistant, and in six institutions, this rate exceeded 60%. MORSA accounted for 91.2% of all oxacillin-resistant isolates. Distinct resistance patterns predominated at various sites within the APAC region, suggesting the local evolution of resistant clones. Non-multidrug-resistant strains were frequent in one part of Australia. No vancomycin-intermediate strains were detected, and no strains were resistant to linezolid or quinupristin-dalfopristin. MORSA strains are a very common cause of infection in hospitalized patients in the APAC region.
Eighteen of 25 isolates of Salmonella enterica serovar Typhi were multidrug resistant and contained class 1 integrons with a single cassette, dfrVII or aadA1. The dfrVII-containing integron was likely borne on an IncHI1 plasmid. Salmonella serovar Typhi could become resistant to broad-spectrum cephalosporins by integrating cassettes, such as veb-1, a common cassette in Asia.
Resistance to antimalarial drugs is a public health problem worldwide. Molecular markers for drug-resistant malaria, such as pfcrt and pfmdr1 polymorphisms, could serve as useful surveillance tools. To evaluate this possibility, sequence polymorphisms in pfcrt (position 76) and pfmdr1 (positions 86, 184, 1034, 1042, and 1246) and in vitro drug sensitivities were measured for 65 Plasmodium falciparum isolates from Thailand, Myanmar, Vietnam, and Bangladesh. The pfcrt Thr76 polymorphism was present in 97% of samples, consistent with observations that chloroquine resistance is well established in this region. Polymorphisms in pfmdr1 clustered into four specific patterns: the wild type (category I), a Tyr86 polymorphism only (category II), a Phe184 polymorphism only (category III), and Phe184 in combination with Cys1034 and/or Asp1042 (category IV). Isolates in categories I and III were more sensitive to chloroquine and more resistant to mefloquine, artesunate, and artemisinin than isolates in categories II and IV (P </= 0.01). Mefloquine resistance was significantly more common in category I and III isolates than in category II and IV isolates, with a prevalence ratio of 14.95 (95% confidence interval, 3.88 to 57.56). These categories identified mefloquine resistance with a sensitivity and a specificity of 94 and 91%, respectively. The pfmdr1 gene copy number was measured by real-time PCR as a ratio of the amount of pfmdr1 DNA to the amount of lactate dehydrogenase (ldh) DNA. Eight samples had pfmdr1 DNA/ldh DNA ratios >/=3. The isolates in all 8 samples fell into categories I and III and were significantly more resistant to mefloquine, quinine, artemisinin, and artesunate and more sensitive to chloroquine than the isolates in the 57 samples with <3 copies of the gene (P </= 0.001). Thus, measurement of pfmdr1 mutations and gene copy number may be useful for surveillance of mefloquine-resistant malaria in Southeast Asia.
A total of 685 clinical Streptococcus pneumoniae isolates from patients with pneumococcal diseases were collected from 14 centers in 11 Asian countries from January 2000 to June 2001. The in vitro susceptibilities of the isolates to 14 antimicrobial agents were determined by the broth microdilution test. Among the isolates tested, 483 (52.4%) were not susceptible to penicillin, 23% were intermediate, and 29.4% were penicillin resistant (MICs >/= 2 mg/liter). Isolates from Vietnam showed the highest prevalence of penicillin resistance (71.4%), followed by those from Korea (54.8%), Hong Kong (43.2%), and Taiwan (38.6%). The penicillin MICs at which 90% of isolates are inhibited (MIC(90)s) were 4 mg/liter among isolates from Vietnam, Hong Kong, Korea, and Taiwan. The prevalence of erythromycin resistance was also very high in Vietnam (92.1%), Taiwan (86%), Korea (80.6%), Hong Kong (76.8%), and China (73.9%). The MIC(90)s of erythromycin were >32 mg/liter among isolates from Korea, Vietnam, China, Taiwan, Singapore, Malaysia, and Hong Kong. Isolates from Hong Kong showed the highest rate of ciprofloxacin resistance (11.8%), followed by isolates from Sri Lanka (9.5%), the Philippines (9.1%), and Korea (6.5%). Multilocus sequence typing showed that the spread of the Taiwan(19F) clone and the Spain(23F) clone could be one of the major reasons for the rapid increases in antimicrobial resistance among S. pneumoniae isolates in Asia. Data from the multinational surveillance study clearly documented distinctive increases in the prevalence rates and the levels of antimicrobial resistance among S. pneumoniae isolates in many Asian countries, which are among the highest in the world published to date.
Lactococcus garvieae (junior synonym, Enterococcus seriolicida) is a major pathogen of fish, producing fatal septicemia among fish species living in very diverse environments. The phenotypic traits of L. garvieae strains collected from three different continents (Asia, Europe, and Australia) indicated phenotypic heterogeneity. On the basis of the acidification of D-tagatose and sucrose, three biotypes were defined. DNA relatedness values and a specific PCR assay showed that all the biotypes belonged to the same genospecies, L. garvieae. All of the L. garvieae strains were serotyped as Lancefield group N. Ribotyping proved that one clone was found both in Japan, where it probably originated, and in Italy, where it was probably imported. PCR of environmental samples did not reveal the source of the contamination of the fish in Italy. Specific clones (ribotypes) were found in outbreaks in Spain and in Italy. The L. garvieae reference strain, isolated in the United Kingdom from a cow, belonged to a unique ribotype. L. garvieae is a rising zoonotic agent. The biotyping scheme, the ribotyping analysis, and the PCR assay described in this work allowed the proper identification of L. garvieae and the description of the origin and of the source of contamination of strains involved in outbreaks or in sporadic cases.
We describe the first freshwater members of the class Actinobacteria that have been isolated. Nine ultramicro-size (<0.1 microm(3)) strains were isolated from five freshwater habitats in Europe and Asia. These habitats represent a broad spectrum of ecosystems, ranging from deep oligotrophic lakes to shallow hypertrophic lakes. Even when the isolated strains were grown in very rich media, the cell size was <0.1 microm(3) and was indistinguishable from the cell sizes of bacteria belonging to the smaller size classes of natural lake bacterioplankton. Hybridization of the isolates with oligonucleotide probes and phylogenetic analysis of the 16S rRNA gene sequences of the isolated strains revealed that they are affiliated with the class Actinobacteria and the family Microbacteriaceae. The previously described species with the highest levels of sequence similarity are Clavibacter michiganensis and Rathayibacter tritici, two phytopathogens of terrestrial plants. The 16S rRNA gene sequences of the nine isolates examined are more closely related to cloned sequences from uncultured freshwater bacteria than to the sequences of any previously isolated bacteria. The nine ultramicrobacteria isolated form, together with several uncultured bacteria, a diverse phylogenetic cluster (Luna cluster) consisting exclusively of freshwater bacteria. Isolates obtained from lakes that are ecologically different and geographically separated by great distances possess identical 16S rRNA gene sequences but have clearly different ecophysiological and phenotypic traits. Predator-prey experiments demonstrated that at least one of the ultramicro-size isolates is protected against predation by the bacterivorous nanoflagellate Ochromonas sp. strain DS.
A serotyping assay for hepatitis C virus (HCV) was evaluated with samples from Thailand, where the distribution of HCV genotypes was different from that in Western countries where the assay was designed and validated. The sensitivity of the assay was low (58%) for HCV RNA-positive samples compared to that of the genotyping assay (95%, P < 0.01). In addition, only 36% of anti-HCV-positive but HCV RNA-negative samples could be serotyped. The serotypes and genotypes were identical in 96% of the samples that could be typed by both methods. Most of the samples with genotype 6, which was common in Southeast Asia, were nontypeable by this serotyping assay.
A collection of 207 historically relevant Burkholderia pseudomallei isolates was analyzed by multilocus sequence typing (MLST). The strain collection contains environmental isolates obtained from a geographical distribution survey of B. pseudomallei isolates in Thailand (1964 to 1967), as well as stock cultures and colony variants from the U.S. Army Medical Research Unit (Malaysia), the Walter Reed Army Institute for Research, and the Pasteur Institute (Vietnam). The 207 isolates of the collection were resolved into 80 sequence types (STs); 56 of these were novel. eBURST diagrams predict that the historical-collection STs segregate into three complexes when analyzed separately. When added to the 760 isolates and 365 STs of the B. pseudomallei MLST database, the historical-collection STs cluster significantly within the main complex of the eBURST diagram in an ancestral pattern and alter the B. pseudomallei "population snapshot." Differences in colony morphology among reference isolates were found not to affect the STs assigned, which were consistent with the original isolates. Australian ST84 is likely characteristic of B. pseudomallei isolates of Southeast Asia rather than Australia, since multiple environmental isolates from Thailand and Malaysia share this ST with the single Australian clinical isolate in the MLST database. Phylogenetic evidence is also provided suggesting that Australian isolates may not be distinct from those of Thailand, since ST60 is common to environmental isolates from both countries. MLST and eBURST are useful tools for the study of population biology and epidemiology, since they provide methods to elucidate new genetic relationships among bacterial isolates.
Presently, most Neisseria gonorrhoeae testing is based on beta-lactamase tests and agar dilution with common therapeutic agents. The National Committee for Clinical Laboratory Standards (NCCLS) recently described a disk diffusion test that produced results similar to the reference agar dilution method for the antibiotic susceptibility of N. gonorrhoeae. We obtained 71 gonococcal isolates from active-duty males aboard a United States Navy vessel while deployed in the Western Pacific during 1989. In addition, 47 isolates of N. gonorrhoeae were obtained from sexually transmitted disease clinics within the branch clinic operations of the Naval Hospital, San Diego (SD), and tested. Antibiotic susceptibility tests by using the NCCLS agar dilution and disk diffusion techniques were compared. Among the Southeast Asia (SEA) isolates, 47% were beta-lactamase producers compared with 10.5% of the SD isolates. The mean MICs (SEA/SD) in micrograms per milliliter for both groups were as follows: penicillin, 88/15; tetracycline, 2.2/0.95; erythromycin, 1.2/0.49; ceftriaxone, 0.016/0.012; cefotaxime, 0.034/0.03; cefuroxime, 0.44/0.17; cefoxitin, 1.3/0.97; spectinomycin, 150/131; ciprofloxacin, 0.07/0.034; norfloxacin, 0.77/0.29; lomefloxacin, 0.15/0.0.056; and ofloxacin, 0.07/0.036. The established NCCLS interpretive criteria for both susceptibility methods appear applicable to domestic gonococcal strains. However, modifications may be necessary for the more antimicrobial agent-resistant SEA isolates on the basis of the clinical success and cure rates following the indicated single-dose regimens for the geographic region.
Hemagglutinin sequences of 146 human influenza A/H3N2 strains identified in respiratory specimens from Asia and Europe during the 2001-2003 influenza seasons were analyzed by DNA sequencing. Our results suggest that four amino acid substitutions, L25I, H75Q, H155T, and Q156H, led to the antigenic conversion of the previously predominant A/Panama/2007/99-like strains to the more recent A/Fujian/411/2002-like strains.
The spread of highly pathogenic avian influenza H5N1 viruses across Asia in 2003 and 2004 devastated domestic poultry populations and resulted in the largest and most lethal H5N1 virus outbreak in humans to date. To better understand the potential of H5N1 viruses isolated during this epizootic event to cause disease in mammals, we used the mouse and ferret models to evaluate the relative virulence of selected 2003 and 2004 H5N1 viruses representing multiple genetic and geographical groups and compared them to earlier H5N1 strains isolated from humans. Four of five human isolates tested were highly lethal for both mice and ferrets and exhibited a substantially greater level of virulence in ferrets than other H5N1 viruses isolated from humans since 1997. One human isolate and all four avian isolates tested were found to be of low virulence in either animal. The highly virulent viruses replicated to high titers in the mouse and ferret respiratory tracts and spread to multiple organs, including the brain. Rapid disease progression and high lethality rates in ferrets distinguished the highly virulent 2004 H5N1 viruses from the 1997 H5N1 viruses. A pair of viruses isolated from the same patient differed by eight amino acids, including a Lys/Glu disparity at 627 of PB2, previously identified as an H5N1 virulence factor in mice. The virus possessing Glu at 627 of PB2 exhibited only a modest decrease in virulence in mice and was highly virulent in ferrets, indicating that for this virus pair, the K627E PB2 difference did not have a prevailing effect on virulence in mice or ferrets. Our results demonstrate the general equivalence of mouse and ferret models for assessment of the virulence of 2003 and 2004 H5N1 viruses. However, the apparent enhancement of virulence of these viruses in humans in 2004 was better reflected in the ferret.
The Western Pacific and South East Asia regions are the largest and most populous of the six World Health Organisation regions and include more than 40 countries. More than 75% of the world's estimated 350 million carriers are located here. The region has therefore provided many insights into the epidemiology, natural history, and control of hepatitis B infection and has been home to the first national control programmes. Hepatitis B is hyperendemic in most countries of the region, with carrier rates ranging from 5-35% except in Australia, New Zealand, and Japan, where the mean carrier rate is less than 2%. Patterns of infection vary considerably from country to country, city to city, and even village to village, and can change with time. Most infections are acquired early in childhood or in early adult life. A variety of control measures are in place and many countries in the region have introduced widespread or universal childhood immunisation policies with significant success. While it is theoretically possible that hepatitis B infection could be eradicated by universal childhood immunisation, there are several biological and practical issues that make this extremely difficult, suggesting that, for the foreseeable future, control may be a more realisable goal.
Process models offer opportunities to explore the effectiveness of different programme and policy alternatives by varying input behaviours and model parameters to reflect programmatic/policy effects. The Asian Epidemic Model (AEM) has been designed to reflect the primary groups and transmission modes driving HIV transmission in Asia. The user adjusts AEM fitting parameters until HIV prevalence outputs from the model agree with observed epidemiological trends. The AEM resultant projections are closely tied to the epidemiological and behavioural data in the country. In Thailand and Cambodia they have shown good agreement with observed epidemiological trends in surveillance populations and with changes in HIV transmission modes, AIDS cases, male:female ratios over time, and other external validation checks. By varying the input behaviours and STI trends, one can examine the impact of different prevention efforts on the future course of the epidemic. In conclusion, the AEM is a semi-empirical model, which has worked well in Asian settings. It provides a useful tool for policy and programme analysis in Asian countries.
In summary, members of the TF/STD: share the common goal of reducing the STD burden and slowing the spread of HIV in the most affected and vulnerable countries in eastern Europe and central Asia contribute financially, technically, or in kind to the implementation of a joint strategy which aims: to create an enabling environment for STD prevention and control, and to strengthen the local capacity for STD prevention and care engage in a continuous exchange of information, collaborative partnerships, and coordination of activities at regional as well as country level through the TF/STD and in-country interagency working groups, respectively concur with the priority areas for international support consisting of advocacy and policy, STD drugs, condoms, educational materials, training, applied research, and surveillance meet twice a year to review implementation progress and the need for additional assistance as advocates of TF/STD, call on partners and other organisations to join in this important new initiative.
Many countries in Southeast Asia have the experience of traditional treatments of drug dependence, or have healers who are extending traditional methods to meet contemporary needs. Some treatments, for example those used in some Buddhist monasteries in Thailand and clinics in Japan, rely upon the philosophical and religious traditions of the country; others come closer to faith healing and magic in their practices; and many use herbal preparations during detoxification and afterwards, as well as offering spiritual or secular therapy. This paper argues that careful evaluation be made of the methods and outcome of these traditional treatments of drug dependence and summarizes some of the evidence so far published.
Three populations of Southeast Asia comprising 191 Chinese, 121 Malays and 150 Indians, were studied with respect to two recently described mutant luteinizing hormone (LH) variants using molecular techniques. One of these variants had Trp8 to Arg8 and Ile15 to Thr15 replacements in exon 2 of the LH beta-subunit, while the other variant possessed Ser102 substitution for Gly102 in exon 3. The exon 2 mutants were in complete linkage disequilibrium. The exon 2 variant had an allele frequency of 0.045 in Chinese, 0.062 in Malays and 0.030 in Indians. The allele frequency of the exon 3 variant was 0.018 in Chinese and null in Malays and Indians. The two LH variants may be markers of interest in studies of disturbed pituitary-gonadal function, menstrual disorders and female infertility.