Stewardship / Resistance Scan for Feb 01, 2017

News brief

MCR-1 identified in California; Vietnam notes link to ag colistin use

The Los Angeles County Department of Public Health (LAC DPH) reported yesterday that a bacterial isolate harboring the MCR-1 gene, which confers resistance to the last-resort antibiotic colistin, has been identified in a patient with an Escherichia coli infection.   

Department officials said in a press release that the patient had most likely acquired the E coli infectionduring international travel, and that there has been no evidence that the infection is spreading in the local healthcare community. The MCR-1 gene has now been reported in six human cases in the United States.
Jan 31 LAC DPH press release

Meanwhile, a study yesterday in Emerging Infectious Diseases suggests that the spread of the MCR-1 gene in Vietnam is linked to the use of colistin in agriculture. The drug is one of the most commonly used antimicrobials in animal production in Vietnam.

For the study, investigators conducted a systematic, cross-sectional study examining antimicrobial drug use colonization with antimicrobial-resistant E coli in chickens and human in Tien Giang province. They collected fecal samples from 204 chicken farms and 204 rectal swabs from chicken farmers, and additionally collected rectal swabs from age- and sex-matched individuals from the same districts who were not involved in poultry farming.

In a total of 204 chicken and 510 human fecal specimens, the adjusted prevalence of MCR-1 was 59.4% in the chicken samples and 20.6% in the human samples. Of the 200 E coli isolates collected, the MCR-1 gene was detected in 10 of 78 isolates from chickens (12.8%), 2 of 50 isolates from chicken farmers (4%), and in none of the 78 isolates from non-farmers. MCR-1 was also detected in 9 of 38 and 1 off 44 extended spectrum beta-lactamase (ESBL)-producing E coli isolates from chickens and chicken farmers, respectively.

An investigation of risk factors indicated that colonization with MCR-1–carrying bacteria in chickens is associated with the use of colistin on chicken farms, while colonization in humans is associated with exposure to MCR-1–positive chickens, with zoonotic transmission explaining the high prevalence of the gene (34.7%) in farmers.

"Given the potentially serious consequences of the spread of the mcr-1 gene from food production animals to humans, prudent use of antimicrobial drugs in animal production should be enforced globally, including in small-scale and household farms," the authors write.
Jan 31 Emerg Infect Dis dispatch

 

Myanmar study finds evidence of drug resistance in asymptomatic malaria

Researchers investigating malaria infections in an artemisinin resistance containment zone in Myanmar identified isolates from asymptomatic malaria infections that contained a resistance gene, according to a study yesterday in Emerging Infectious Diseases.

The investigators, from Myanmar and South Korea, analyzed isolates from 1,182 people in the containment zone, which is known to harbor mosquitoes containing the Plasmodium falciparum parasite resistant to the antimalarial drug artemisinin, as well as P vivax resistant to chloroquine. Of the 1,182 people, 549 (46%) had had malaria in the previous 5 years.

The researchers discovered that 28 isolates were from asymptomatic people. Of those, 22 were caused by P vivax, 4 by P falciparum, and 2 by P malariae. Two of the P falciparum isolates harbored K13 mutations, an established artemisinin-resistance marker. Three of the P vivax isolates contained other drug-resistance markers.

The authors conclude, "Our results indicated that drug-resistant malaria parasites may be spreading, even in the containment areas or (pre-)elimination areas; this issue should, therefore, be addressed at a policy level. Detection and elimination of asymptomatic infections are of vital importance."
Jan 31 Emerg Infect Dis study

 

Chinese report notes high rate of travel in those with ESBL bacteria

A study in the latest issue of The Lancet Infectious Diseases shows that more than two thirds of Chinese patients with extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) infections had traveled recently.

The Chinese/UK/US team collected 3,476 third-generation cephalosporin-resistance Enterobacteriaceae isolates from fecally colonized outpatients (3,322 Escherichia coli, 124 Klebsiella pneumoniae, 16 Proteus mirabilis, and 14 Enterbacter cloacae). Of the 3,476 isolates, 2,115 (61%) were positive for at least one ESBL gene.

Among outpatients with ESBL-E isolates, 1,457 (69%) of 2,115 people had documented travel in the previous 6 months; 273 (19%) of them had traveled abroad and 1,184 (81%) had not. The most common destinations outside of China were other parts of Asia (45%), Europe (24%), and the United States (20%).

The authors conclude, "Although the temporal relationship of travel and sampling in our retrospective analysis makes it difficult to conclude whether patients were colonised with ESBL-E at the time, during, or after travel, our findings suggest that further studies, and perhaps microbiological surveillance, of ESBL-E in international travellers from areas with high colonisation prevalence are warranted."
February Lancet Infect Dis report

News Scan for Feb 01, 2017

News brief

Portugal reports first H5N8 detection

Portugal yesterday reported its first highly pathogenic H5N8 avian influenza detection, in a grey heron found dead near the southern city of Faro, according to a notice yesterday from the United Nations Food and Agriculture Organization (FAO). In several countries in Europe and other regions that have had H5N8 outbreaks, the virus was first found in wild birds before jumping to poultry.

In other H5N8 developments, four European countries reported more outbreaks in wild birds and poultry, according to the latest reports to the World Organization for Animal Health (OIE). The Czech Republic reported four more outbreaks in poultry, three in backyard birds and one at a farm, that began between Jan 28 and Jan 31, killing 1,283 of 14,230 susceptible birds. Officials also reported one more wild bird outbreak, involving a mute swan found dead in a forest in South Bohemian region.

Romania reported 15 more H5N8 outbreaks, 5 in backyard poultry and 10 in wild birds. The events all began on Jan 27 and affected six counties in the eastern half of the country. All of the wild bird outbreaks occurred at nature parks, with whooper swans accounting for most of the deaths. In the backyard poultry outbreaks, the virus killed 250 of 585 susceptible birds.

Elsewhere, Serbia reported seven more outbreaks in wild birds found dead in nature parks from Jan 25 to Jan 27. The 43 mute swans that died from the virus were from four districts in northern Serbia.
Jan 31 FAO notice
Feb 1 OIE report on H5N8 in Czech Republic poultry
Feb 1 OIE report on H5N8 in Czech Republic wild birds
Feb 1 OIE report on H5N8 in Romania
Jan 31 OIE report on H5N8 in Serbia

 

Groups detail Madagascar plague outbreak, ciprofloxacin treatment

Two new articles in Emerging Infectious Diseases describe the challenges of limiting human-to-human transmission of pneumonic plague in a small cluster of cases in Madagascar, while the antibiotic ciprofloxacin successfully treated cases of plague in five patients.

Madagascar is one of the most plague-ridden countries in the world, and though rare, the country has reported cases of pneumonic plague. This type of plague is the most lethal form of infection with Yersinia pestis, because the disease can be spread via droplets from coughing and sneezing.

In 2015, researchers followed 14 patients complaining of fever and pneumonia. Five of the 14 has confirmed pneumonic plague while the other 9 were suspected or likely cases. Exposure was traced back to family members and friends who attended a 2-day burial for a 22-year-old man who died from pneumonic plague. Though the region where the cases occurred had no reports of human plague in 13 years, a reservoir of infected fleas existed in local rodents.

The overall case-fatality rate was 71%, and the average duration from symptom onset to death was 1.9 days. The authors said that poor public health infrastructure and burial customs contributed to pneumonic plague transmission.
Jan 31 Emerg Infect Dis Madagascar plague study

In other plague news, a team from Uganda and the US Centers for Disease Control and Prevention recently described the successful treatment of human plague with ciprofloxacin, approved by the Food and Drug Administration for the treatment of plague in 2015, in five Uganda patients, including a 13-year-old boy who had pneumonic plague.

The patients were given ciprofloxacin for 10 days at a weight-calibrated dosage of 15 mg/kg, with a maximum dose for adults of 750 mg twice daily. All patients were cleared of infection and discharged from medical care by 14 days post-infection.

Without antibiotics, bubonic plague has a 50% mortality rate, and pneumonic plague is almost always lethal with a 90% mortality rate.
Jan 31 Emerg Infect Dis plague antibiotic study

 

MERS in Pakistani camels expands range to Asia

Dromedary camels are known reservoirs for MERS-CoV, or Middle East respiratory syndrome coronavirus. In Emerging Infectious Diseases, researchers report that 39% of all camels tested in Pakistan had neutralizing antibodies against MERS-CoV, which means there is a risk of human exposure and transmission.

One-humped camels are widely found in Africa, the Middle East, and parts of Asia. In Saudi Arabia, they've been linked to several hundreds of cases of MERS-CoV in humans, but evidence the virus has not been previously found in Asian dromedary camels. In this study, researchers analyzed serum samples from 565 camels (median age 5 years) from nine regions in Pakistan. According to researchers, the rate of neutralizing antibody–positive camel samples ranged from 82.9% in Rahim Yar Khan to 24.1% in the Jhang district. The samples were collected from 2012 to 2015.

Pakistan is home to more than 1 million dromedary camels and neighbors India's Rajasthan state, also home to a large population of camels.
Jan 31 Emerg Infect Dis study

 

Afghanistan polio vaccine campaign targets 5.6 million children

Afghanistan's health ministry, along with the World Health Organization (WHO) and UNICEF this week launched the first large polio vaccination campaign of the year, targeting more than 5.6 million children, the WHO's Eastern Mediterranean Regional Office (WHO EMRO) said in a statement.

The campaign focuses on provinces in the south and southeast, most districts in the east, and select high-risk districts across the country, including Kabul. Dr Maiwand Ahmadzi, director of the health ministry's national emergency operations center for polio eradication, said the goal is to build on strong progress in 2016, a year when Afghanistan had only 13 cases, a drop from 20 in 2015. "This was made possible through hard work by thousands of frontline health workers and a renewed emphasis on monitoring and oversight."

More than 31,000 trained polio workers are carrying out the campaign, scheduled to run through Feb 3. Then vaccinators will revisit the children they missed during the first visit.

Afghanistan is one of three remaining polio-endemic countries, alongside Nigeria and Pakistan. Hemant Shukla, MD, who directs the WHO's polio program, said most of Afghanistan is now polio-free, with circulation restricted to small areas in the east, south, and southeast. "We have seen huge improvements in vaccination campaign quality. Our focus is now on reaching every single child during every vaccination campaign to stop the transmission of polio."
Jan 30 WHO EMRO statement

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