Two suspected Ebola cases confirmed in DRC
The Democratic Republic of the Congo (DRC) on Jun 2 said that two suspected Ebola cases had been confirmed via laboratory testing. According to the World Health Organization (WHO), these cases came from known transmission chains, and the date of the last confirmed case in the DRC remains May 11.
Since Apr 21, there have been 4 confirmed and 3 probable Ebola cases, of which 4 have died (case-fatality rate, 57%). The WHO said scientists are currently investigating unusually high mortality in swine populations from eight villages in northern DRC.
Contact follow-up and tracing were already under way for the two confirmed cases, and the WHO said that the outbreak is controlled.
The current outbreak is the DRC's eighth since Ebola virus was first detected in 1976.
Jun 2 WHO bulletin
Aedes aegypti mosquitoes can transmit both Zika, chikungunya in 1 bite
A new study in PLoS Neglected Tropical Diseases shows that the Aedes aegypti mosquito can transmit both Zika and chikungunya virus in one bite, and co-infection with the viruses does not alter vector competence.
Dutch scientists infected the insects with both viruses to determine transmission rates using an experimental blood meal and found that 73% of the mosquitoes transmitted Zika, 21% spread chikungunya, and 12% transmitted both viruses in one bite. This is the first study to show that, just as in humans, the viruses can commonly co-infect mosquitoes.
"We show that ZIKV and CHIKV can simultaneously disseminate to the saliva of Ae. aegypti mosquitoes, indicating that co-infections do not strongly interfere with virus replication," the authors write.
In other Zika news, a vaccine presented at the American Society of Microbiology (ASM) Microbe 2017 meeting that wrapped up today showed 100% protection from the virus in mouse models. The vaccine is the first to be based on the NS1 protein, and the first to show single-dose protection against Zika.
Also at ASM, scientists described a new reliable clinical test that can diagnose Zika in semen samples. The test could be helpful for couples who are planning a pregnancy after a possible Zika exposure.
The test, called the Aptima assay, was found to have 100% sensitivity and specificity in 100 semen samples.
Jun 1 PLoS Negl Trop Dis study
Jun 4 ASM vaccine press release
Jun 4 ASM Zika test press release
PAHO reports 1,000 new chikungunya cases in the Americas
Following a week in which the chikungunya outbreak in the Americas grew by 80%, on Jun 2 the Pan American Health Organization (PAHO), in its weekly report, noted a return to more modest but still notable numbers, as the agency detailed 1,039 new cases.
The new cases lift the yearly total to 87,472, according to the latest update. Previous weekly reports showed increases of 16,436, 142, and 38,282 cases, respectively. The weeks with five-digit increases are those in which Brazil, which has accounted for 93% of 2017 cases, has reported new infections.
The vast majority of new cases were in Bolivia, which reported 855 new chikungunya illnesses and 2,144 for the year. Peru was second, with 123 new cases and 1,120 total. The number of deaths from the disease remained at 13, all of them in Brazil.
Since the chikungunya outbreak began in late 2013 on the Caribbean island of St. Martin, the virus has sickened at least 2,474,499 people.
Jun 2 PAHO update