Study: Plague endemic in Bronze Age humans, mutated in Eurasia
New DNA evidence has shown that Yersinia pestis, the bacterium that causes plaque, has been endemic in humans for at least 3,000 years before the first plague pandemic was recorded, according to findings yesterday in Cell.
An international team of researchers analyzed 89 billion raw DNA sequences from the teeth of 101 Eurasian adults who died between 2,800 to 5,783 years ago. Evidence of Y pestis was found in 7 of them.
Six plague samples were missing mutations that allow Y pestis to survive in fleas and infect human tissues outside of the lungs, indicating that pneumonic plague was endemic and spread through human-to-human transmission during the Bronze Age. The most recent sample of DNA has both mutations, suggesting that the bubonic form of plague carried by fleas and able to infect the human lymphatic system emerged near Armenia around 951 BC.
The evidence implies that Y pestis began infecting humans at the beginning of the Bronze Age, during which pneumonic plague would have spread easily through increased warfare and migratory movements, the researchers wrote. Bubonic plague may have spread out of the Middle East during the 1st millennium.
The earliest recorded plague pandemic is the Plague of Justinian, which occurred in 541 AD. The emergence of plague more than twice as early as previously thought suggests that the bacterium may have been responsible for large death rates observed in Eurasian populations in the 4th and 3rd millennia BC, the authors conclude.
Oct 22 Cell study
US flu activity up a bit but still low, CDC says
Influenza activity was up slightly but still low for the second consecutive week of official reporting for the 2015-16 flu season, the US Centers for Disease Control and Prevention (CDC) reported today, with Guam again reporting widespread flu.
The proportion of people seeing a healthcare provider for influenza-like illness (ILI) rose slightly, from 1.2% the week before to 1.4% for the week ending Oct 17, the CDC said. That is still well below the national baseline of 2.1%, though, and all 10 US regions said ILI reporting was below regional baseline levels.
The percentage of respiratory specimens testing positive for influenza was 1.7%, up from 1.2% the week before but well below the epidemic threshold. For the most recent 3 weeks, the regional percentage ranged from 0.4% to 3.8%, with the highest being in a regional that includes southwestern states plus Hawaii and Guam.
Guam reported widespread geographic flu activity. And four states—Hawaii, Massachusetts, Oklahoma, and Oregon—reported local flu activity, up from one state (Oklahoma) the week before. Hawaii reported regional activity in the previous week, which is more widespread than local.
The proportion of deaths due to pneumonia and influenza reached 5.6%, up from 5.5% the week before but below the epidemic threshold of 6.3%.
Very few specimens testing positive for flu were reported to the CDC last week, with 18 of 19 being influenza A and the other influenza B. Of the 15 "A" viruses that were subtyped, 14 were H3 viruses and 1 was 2009 H1N1.
Oct 23 CDC FluView report
Listeria outbreak tied to soft cheeses reaches 30 cases, 3 deaths
In declaring today that a Listeria outbreak linked to soft cheeses is over, the CDC reported 6 new infections and 2 new deaths, bringing the total to 30 cases and 3 deaths in 10 states. Newly reported cases include one involving a pregnant woman, bringing that total to 6.
Of the 30 patients, 28 required hospitalization. Two of the three deaths were in California, and one of the infected pregnant women miscarried, the CDC said.
"Epidemiologic and laboratory information indicates that soft cheeses distributed by Karoun Dairies of San Fernando, Calif., were the likely source of this outbreak. Twenty-one (75%) of 28 patients with available information reported eating soft cheese in the month before becoming ill. Karoun recalled 15 types of soft cheeses on Sep 16.
The Food and Drug Administration isolated Listeria monocytogenes from two environmental samples collected last month from a Central Valley Cheese, Inc. manufacturing facility in Turlock, Calif., which makes cheese for Karoun Dairies. The two isolates were closely related genetically to isolates from case-patients, the CDC said. Five Listeria isolates collected in 2010 from the same plant were also closely related.
Oct 23 CDC statement
Cholera cases increase in Tanzania, Iraq, DR Congo
Cholera cases in Tanzania have reached 4,922 in an outbreak that now affects 12 regions and has caused 74 deaths, according to a report today in The Nation.
The outbreak, which began in August, spread rapidly in the densely populated urban center of Dar es Salaam, causing an estimated 3,500 cases in the city. The Zanzibar archipelago on Tanzania's coast recently reported 140 cases.
The World Health Organization (WHO) anticipates an increase in cases as Tanzania's rainy season approaches and has requested $2 million for deployment of water trucks, water chlorination efforts, and health education programs, the story said.
Oct 23 Nation article
In related news, the WHO has implemented cholera control efforts in outbreaks affecting Iraq and the Democratic Republic of the Congo (DRC).
As of Oct 20, Iraq has reported 1,811 laboratory-confirmed cases of cholera in 15 of the country's governorates. The outbreak has been attributed to the low level of the Euphrates River and the large number of people displaced by conflict. Cases are expected to increase as people travel for the religious observance of Ashura on Oct 23 and Dec 2, the agency said.
The WHO plans to conduct an oral cholera vaccination campaign in Iraq on Oct 31 and Nov 1 and has allocated 510,000 doses of vaccine for 255,000 displaced persons. Other efforts include the distribution of 15 diarrhea kits to affected Iraqi governorates and deployment of trained staff to carry out case management and outbreak response.
In the DRC, the WHO has distributed 10 emergency health kits in response to an outbreak that has sickened 3,973 people and caused 95 deaths, raising concerns that the disease could spread to the capital of Kinshasa with the advent of the oncoming rainy season.
Oct 22 WHO update
Afghanistan experiences polio eradication progress, setbacks
The WHO and CDC have called for Afghanistan to establish national oversight for polio vaccination because of inadequate vaccination coverage in infants, wild poliovirus type 1 (WPV1) cases in conflict-affected areas, and evidence of transmission across the country's border with Pakistan, according to a Morbidity and Mortality Weekly Report (MMWR) from the CDC today.
Afghanistan reported 9 WPV1 cases in 2015, 5 of which occurred in conflict-affected western provinces. That compares with 28 WPV1 case in 2014 and 14 in 2013. Eight of the 2015 case-patients had never received a dose of oral poliovirus vaccine (OPV).
Polio surveillance activities in Afghanistan during 2014 revealed an acute flaccid paralysis rate of 12.6 per 100,000 population, 6 cases of which were polio-compatible. As of Jul 2014, 18 of 97 environmental samples collected in five provinces tested positive for WPV1.
In 2015, 1% to 3% of 9 million children younger than 5 years were unable to receive OPV during National Immunization Days because they lived in inaccessible areas or because vaccination campaigns had been banned by anti-government groups. In March 2015, Afghan health officials reported that 7% (538,412) of 7.6 million children targeted remained unvaccinated because of inaccessibility, and the WHO and CDC said that only 20% of unvaccinated children were living in accessible areas.
Only 66% to 68% of Afghanistan's districts had reached a poliovirus vaccination threshold at or above 80% of children in 2015. As a result, the WHO and CDC have called for establishment of a national emergency operations center and enhanced immunization efforts.
Oct 23 MMWR report