VHF Scan for Sep 02, 2016

Crimean-Congo fever in Spain
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Late Ebola sexual transmission
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Spain reports its first 2 cases of Crimean-Congo hemorrhagic fever

Spain has reported its first two cases of Crimean-Congo hemorrhagic fever (CCHF)—one of them fatal—a tick-borne viral disease that is found in eastern Europe, the Middle East, Africa, and much of Asia.

The fatal case involved a 62-year-old man who had had a tick bite and died in a Madrid hospital, according to yesterday's weekly communicable disease update from the European Centre for Disease Prevention and Control (ECDC). The other patient is an intensive care nurse who became infected while caring for the 62-year-old man; her condition was not described.

Medical authorities are assessing 200 people who had contact with the two patients, and some are being confined to their homes, the ECDC said.

Although Spain has not had any CCHF cases before, the CCHF virus was found in the country in 2010, according to the infectious disease blog Avian Flu Diary. The blog cited a 2012 report in Emerging Infectious Diseases that said the virus was found in red deer in Caceres, Spain, in 2010. It was closely related to CCHF viruses in Senegal and Mauritania in West Africa, suggesting that it could have been brought to Spain by migratory birds, the report said.

CCHF virus is carried by ixodid (hard) ticks, and many animals, including cattle, sheep, goats, and hares, serve as amplifying hosts, according to the US Centers for Disease Control and Prevention (CDC). Humans catch the disease through tick bites or contact with animal blood, and the virus can spread from person to person via body fluids.

CCHF has a sudden onset and severe symptoms and signs that can include uncontrolled bleeding, according to the CDC. In outbreaks, mortality rates in hospital patients have ranged from 9% to 50%.
Sep 1 ECDC report
Sep 2 Avian Flu Diary post
2012 Emerg Infect Dis report on CCHF virus
CDC information on CCHF

Ebola cluster traced to sexual transmission 15 months after man's illness

A cluster of Ebola cases in Guinea earlier this year has been traced to sexual transmission from a man who had recovered from the disease close to 15 months earlier, marking the longest known period of sexual transmissibility after recovery from the disease.

"Evidence for sexual transmission of the persisting EBOV in February 2016, about 470 days after onset of symptoms in the survivor, is compelling," says the report by an international team of researchers, published yesterday in Clinical Infectious Diseases.

The cluster involved 3 probable and 7 confirmed cases in Guinea, with 8 deaths, in February, March, and April of this year, the report says.

Genomic analysis of the viruses showed they were closely related to strains from West Africa's epidemic, but they were most closely related to a cluster dating to 2014 rather than to late 2015 strains. They matched most closely with the virus from a man who was admitted for treatment in Gueckedou, Guinea, in November 2014 and survived.

An epidemiologic investigation revealed that case-patient 1 from the 2016 cluster had intercourse with the Gueckedou Ebola survivor in late January 2016. Semen samples collected from the survivor on Mar 21 and Apr 9 tested positive for the virus. Genetic sequencing then revealed that his virus was identical to those in cases 4 and 5 of the new cluster, "supporting the epidemiologic evidence of sexual transmission." Additional sequencing and phylogenetic analysis indicated that the whole cluster was linked with the man.

The authors said their results suggest that Ebola virus persisted in the survivor for 531 days—from Oct 26, 2014, until Apr 9, 2016. (Another report from Liberia earlier this week noted that Ebola RNA was found in one survivor's semen 565 after his recovery, but it was not known if it represented viable virus.)

The longest previous case of viable Ebola virus persistence in semen, as indicated by likely transmission, was 179 days after illness onset, the researchers said, citing a 2015 report.

In other observations, the researchers said the virus harbored by the Ebola survivor evolved extremely slowly. Virus in blood collected Nov 3, 2014, differed from that in semen collected Mar 21, 2016, by just five mutations, indicating an evolution rate six times slower than the average rate seen in the West African epidemic.
Sep 1 Clin Infect Dis report
Related Aug 31 CIDRAP News item

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