Jan 31, 2013
Virtually untreatable strain of TB characterized in South Africa
A "totally drug-resistant" type of tuberculosis (TB) may be emerging in South Africa, according to a study in Emerging Infectious Diseases. Drug-resistant, especially multidrug-resistant (MDR), TB is of major concern in the country because of dramatically increasing frequency, dismal treatment success, and limited resources for control, the authors wrote. The researchers, from Eastern Cape province, sought to define the TB strains there and the extent of resistance as well as determine whether the epidemic is being driven by acquisition or transmission of resistance within the strains. A convenience sample of sputum specimens collected from 309 drug-susceptible and 342 MDR-TB patients from July 2008 through July 2009 were characterized by a variety of methods. The drug-sensitive and MDR isolates were found to be genetically distinct from the pre-extensively drug-resistant (pre-XDR) and XDR ones. Second-line drug resistance was significantly associated with an atypical Beijing genotype. Mutations conferring resistance to 10 anti-TB drugs were present in 93% of the atypical Beijing isolates, and some were resistant to para-aminosalicyic acid as well, suggesting that the strain is evolving toward total drug resistance. A high percentage of the atypical Beijing isolates were clustered, indicating transmission rather than acquisition. The authors propose that the Genotype MTBDRplus test, which is the diagnostic standard in most national health labs in the country, be used for rapid screening of patients at risk for the atypical Beijing strains.
Jan 29 Emerg Infect Dis article
CDC reports 20 Salmonella cases linked to pet hedgehogs in 8 states
Twenty people in eight states have been infected with a rare subtype of Salmonella Typhimurium linked to pet hedgehogs, the Centers for Disease Control and Prevention (CDC) said today. Officials have identified through data from PulseNet—the national molecular subtyping network for foodborne disease surveillance—18 cases in 2012 and 2 cases this year of "human Salmonella Typhimurium infections with an indistinguishable pulsed-field gel electrophoresis pattern linked to contact with pet hedgehogs," the agency said in a Morbidity and Mortality Weekly Report (MMWR) update. Typically only one or two instances of the subtype are reported to PulseNet each year. Of the 20 outbreak case-patients, 4 were hospitalized and 1 died. Ages ranged from less than 1 to 91 years, with a median of 13. Of 15 patients with available information, 14 reported direct or indirect contact with a pet hedgehog in the week before illness onset. States with more than one case were Washington, with seven, and Michigan, Minnesota, and Ohio, with three each. The report said that 14 cases of the subtype were reported to PulseNet in 2011 but did not include those numbers in the outbreak report. On Sep 6, 2012, the CDC said the outbreak at that time involved 14 cases.
Feb 1 MMWR report
Sep 7, 2012, CIDRAP News item on earlier outbreak update
Researchers identify novel coronaviruses in Mexican bats
US and Mexican researchers identified 13 distinct coronarivuses (CoVs) in Mexican bats, with 1 of them closely resembling the novel CoV that infected nine people, killing five, in the Middle East in recent months. The team screened 606 bats representing 42 species in Campeche, Chiapas, and Mexico City. Of the 13 CoVs they identified, 9 were alpha-CoVs and 4 were beta-CoVs; 12 were novel. Beta-CoVs include the virus that causes SARS (severe acute respiratory syndrome), but none of the CoVs found in the bats were the SARS-causing virus. They also found that one of the beta-CoVs had a "96.5% amino acid identity" to the novel CoV connected with the Middle East cases, which is also a beta-CoV. Among the team's other findings was that a single species of bat can carry multiple CoVs. They caution, however, "While it is important to investigate unknown viral diversity in bats, it is also important to remember that the majority of viruses they carry will not pose any clinical risk, and bats should not be ubiquitously stigmatized as significant threats to public health."
Jan 30 J Gen Virol abstract
Japan reports first death from emerging bunyavirus infection
Japan's Ministry of Health, Labour and Welfare has reported the country's first death from an emerging bunyavirus infection called severe fever with thrombocytopenia syndrome (SFTS). The syndrome was first reported in 2009 in China, where its mortality rate was estimated at 12%, the Japanese news site The Mainichi reported today. The Japanese victim, an adult from Yamaguchi prefecture, died last fall. The patient had no record of overseas travel, and genetic studies showed the virus came from Japan rather than from China. There was no evidence of a mite bite, which is the usual source of infection, says the story. Symptoms of SFTS include nausea, thrombocytopenia, leukopenia, loss of appetite, and fever