Resistance to artemisinin derivatives, the most potent antimalarial drugs currently used, has emerged in Southeast Asia and threatens to spread to Africa. We report a case of malaria in a man who returned to Vietnam after 3 years in Angola that did not respond to intravenous artesunate and clindamycin or an oral artemisinin-based combination.
BackgroundIatrogenic skin and soft tissue infections by rapidly growing mycobacteria are described with increasing frequency, especially among immunocompromised patients.Case presentationHere, we present an immunocompetent patient with extensive Mycobacterium fortuitum skin and soft tissue infections after subcutaneous injections to relieve joint pains by a Vietnamese traditional medicine practitioner. Moreover, we present dilemmas faced in less resourceful settings, influencing patient management.ConclusionThis case illustrates the pathogenic potential of rapid growing mycobacteria in medical or non-medical skin penetrating procedures, their world-wide distribution and demonstrates the dilemmas faced in settings with fewer resources.
Enteroviruses (EVs) are a genetically and antigenically diverse group of viruses infecting humans. A mostly distinct set of EV variants have additionally been documented to infect wild apes and several, primarily captive, Old World monkey (OWM) species. To investigate the prevalence and genetic characteristics of EVs infecting OWMs in the wild, fecal samples from mandrills (Mandrillus sphinx) and other species collected in remote regions of southern Cameroon were screened for EV RNA. Remarkably high rates of EV positivity were detected in M. sphinx (100 of 102 screened), Cercocebus torquatus (7/7), and Cercopithecus cephus (2/4), with high viral loads indicative of active infection. Genetic characterization in VP4/VP2 and VP1 regions allowed EV variants to be assigned to simian species H (EV-H) and EV-J (including one or more new types), while seven matched simian EV-B variants, SA5 and EV110 (chimpanzee). Sequences from the remaining 70 formed a new genetic group distinct in VP4/2 and VP1 region from all currently recognized human or simian EV species. Complete genome sequences were obtained from three to determine their species assignment. In common with EV-J and the EV-A A13 isolate, new group sequences were chimeric, being most closely related to EV-A in capsid genes and to EV-B in the nonstructural gene region. Further recombination events created different groupings in 5' and 3' untranslated regions. While clearly a distinct EV group, the hybrid nature of new variants prevented their unambiguous classification as either members of a new species or as divergent members of EV-A using current International Committee on Taxonomy of Viruses (ICTV) assignment criteria.
Picornaviruses infecting pigs, described for many years as "porcine enteroviruses", have recently been recognised as containing viruses within three distinct genera (Teschovirus, Sapelovirus and Enterovirus). To better characterise the epidemiology and genetic diversity of members of the Enterovirus genus, faecal samples from pigs from four provinces in Vietnam were screened by polymerase chain reaction using conserved enterovirus-specific primers from the 5 untranslated region. High rates of infection were recorded in pigs on all farms, with detection frequencies of approximately 90% in recently weaned pigs but declining to 40% in those aged over one year. No differences in EV detection rates were observed between pigs with and without diarrhoea (74% [n=70] compared with 72% [n=128]). Genetic analysis of consensus VP4/VP2 and VP1 sequences amplified from a subset of EV-infected pigs identified species G EVs in all samples. Among these, VP1 sequence comparisons identified six type 1 and seven type 6 variants while four further VP1 sequences failed to group with any previously identified EV-G types. These have now been formally assigned as EV-G types 8-11 by the Picornavirus Study Group. Comparison of VP1, VP4/VP2, 3Dpol and 5untranslated regions of study samples and those available on public databases showed frequent, bootstrap supported differences in their phylogenies indicative of extensive within-species recombination between genome regions. In summary, we have identified extremely high frequencies of infection with EV-G in pigs in Vietnam, substantial genetic diversity and recombination within the species and evidence for a much large number of circulating EV-G types than currently described.
A total of 139 stool samples from wild chimpanzees, gorillas and bonobos in Cameroon and Democratic Republic of Congo (DRC) were screened for enteroviruses (EVs) by RT-PCR. EV RNA was detected in 10% of samples, comprising 8 from 58 sampled chimpanzees (13.8%), 1/40 bonobos (2.5%) and 5/40 gorillas (12.2%). Three chimpanzee variants grouped with human isolate EV-A89 while four (4 chimpanzee, 1 gorilla) represented a newly identified type, EV-A119. These species A virus types overlapped with those circulating in human populations in the same area. The remaining six strains comprised a new species D type, EV-D120, infecting one chimpanzee and 4 gorillas, and a single EV variant infecting a bonobo that was remarkably divergent from other EVs and potentially constitutes a new enterovirus species. The study demonstrates both the circulation of genetically divergent EV variants in apes and monkeys as well as those shared with local human populations.
Streptococcus suis is a pathogen of major economic significance to the swine industry and is increasingly recognized as an emerging zoonotic agent in Asia. In Vietnam, S. suis is the leading cause of bacterial meningitis in adult humans. Zoonotic transmission is most frequently associated with serotype 2 strains and occupational exposure to pigs or consumption of infected pork. To gain insight into the role of pigs for human consumption as a reservoir for zoonotic infection in southern Vietnam, we determined the prevalence and diversity of S. suis carriage in healthy slaughterhouse pigs. Nasopharyngeal tonsils were sampled from pigs at slaughterhouses serving six provinces in southern Vietnam and Ho Chi Minh City area from September 2006 to November 2007. Samples were screened by bacterial culture. Isolates of S. suis were serotyped and characterized by multi locus sequence typing (MLST) and pulse field gel electrophoresis (PFGE). Antibiotic susceptibility profiles and associated genetic resistance determinants, and the presence of putative virulence factors were determined. 41% (222/542) of pigs carried S. suis of one or multiple serotypes. 8% (45/542) carried S. suis serotype 2 which was the most common serotype found (45/317 strains, 14%). 80% of serotype 2 strains belonged to the MLST clonal complex 1,which was previously associated with meningitis cases in Vietnam and outbreaks of severe disease in China in 1998 and 2005. These strains clustered with representative strains isolated from patients with meningitis in PFGE analysis, and showed similar antimicrobial resistance and virulence factor profiles. Slaughterhouse pigs are a major reservoir of S. suis serotype 2 capable of causing human infection in southern Vietnam. Strict hygiene at processing facilities, and health education programs addressing food safety and proper handling of pork should be encouraged.
Streptococcus suis infection, an emerging zoonosis, is an increasing public health problem across South East Asia and the most common cause of acute bacterial meningitis in adults in Vietnam. Little is known of the risk factors underlying the disease.
Malaria is still prevalent in rural communities of central Vietnam even though, due to deforestation, the primary vector Anopheles dirus is uncommon. In these situations little is known about the secondary vectors which are responsible for maintaining transmission. Basic information on the identification of the species in these rural communities is required so that transmission parameters, such as ecology, behaviour and vectorial status can be assigned to the appropriate species.
Various amounts of Nb(2)O(5) in the (Na(0.5)K(0.5)) NbO(3) (NKN) ceramic were replaced by V(2)O(5) to decrease its sintering temperature to below 950 degrees C. A small V(2)O(5) content resulted in a dense microstructure with an increased grain size for the specimen sintered at 900 degrees C due to the presence of a liquid phase. When V(2)O(5) was added to the NKN ceramics, their orthorhombic-to-tetragonal transition temperature increased from 178 degrees C to around 200 degrees C. However, their Curie temperature decreased from 402 degrees C to around 330 degrees C. The k(p), epsilon(3) (T)/epsilon(0), and Q(m) values increased with V(2)O(5) addition, probably due to the increased density and poling state, which was identified by the phase angle. The specimen with x = 0.05, sintered at 900 degrees C for 8 h, exhibited the following piezoelectric properties: k(p) = 0.32, epsilon(3) (T)/epsilon(0) = 245, d(33) = 120 (pC/N), and Q(m) = 232.
Between 2003 and 2005, highly pathogenic avian influenza A (H5N1) viruses caused large scale outbreaks in poultry in the Ho Chi Minh City area in Vietnam. We studied the prevalence of antibodies against H5N1 in poultry workers and cullers who were active in the program in Ho Chi Minh City in 2004 and 2005.
The association of ERAP1 with ankylosing spondylitis (AS)1 among HLA-B27-positive individuals suggests that ERAP1 polymorphism may affect pathogenesis by altering peptide-dependent features of the HLA-B27 molecule. Comparisons of HLA-B*27:04-bound peptidomes from cells expressing different natural variants of ERAP1 revealed significant differences in the size, length, and amount of many ligands, as well as in HLA-B27 stability. Peptide analyses suggested that the mechanism of ERAP1/HLA-B27 interaction is a variant-dependent alteration in the balance between epitope generation and destruction determined by the susceptibility of N-terminal flanking and P1 residues to trimming. ERAP1 polymorphism associated with AS susceptibility ensured efficient peptide trimming and high HLA-B27 stability. Protective polymorphism resulted in diminished ERAP1 activity, less efficient trimming, suboptimal HLA-B27 peptidomes, and decreased molecular stability. This study demonstrates that natural ERAP1 polymorphism affects HLA-B27 antigen presentation and stability in vivo and proposes a mechanism for the interaction between these molecules in AS.
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