News Scan for Jul 15, 2016

Yellow fever spike
;
Neuro problems in Ebola
;
Preventing asymptomatic dengue
;
HIV, hepatitis, TB in prisoners

WHO: 73 more yellow fever cases in Angola, 491 more in DRC

In its weekly yellow fever situation report, the World Health Organization (WHO) today noted 73 more cases of the disease in Angola, bringing that country's suspected cases to 3,625.

The Democratic Republic of the Congo (DRC), in contrast, had a huge spike in cases, 491 more than last week, raising the number of suspected cases to 1,798. The DRC also reported 10 more deaths as of Jul 11, bringing the total number of fatalities to 85.

In Angola, cases continue to appear in Luanda and Hambo, but the WHO said Benguela province, and in particular the cities of Benguela and Lobito, is of growing concern. Surveillance remains low in these areas despite vaccination campaigns. There were also 2 more deaths this week, bringing Angola's total fatalities to 357.

For the third week in a row, the DRC reported no new epidemiologic information besides the increase in suspected cases and deaths. Vaccination efforts and surveillance programs, however, remain steadfast, the WHO said. On Jul 20, reactive vaccination campaigns will begin in Kisenso in Kinshasa province and in Kwango province. Kinshasa is one of the most populated cities in Africa, and the WHO and Gavi, the Vaccine Alliance, have made vaccination in that city a top priority.
Jul 15 WHO situation report

 

Study: Ebola virus in spinal fluid may explain neurologic changes

Ebola virus (EBOV) was found in the cerebrospinal fluid (CSF) of three patients in Guinea during the recent epidemic there, which may help explain the neurologic signs that have sometimes been observed in Ebola patients, according to a report yesterday in Clinical Infectious Diseases.

The authors, from Guinea and France, wrote that until now, Ebola virus was detected in the CSF of Ebola patients in only two isolated cases, and the pathophysiology of neurologic changes in such cases has never been made clear.

After noticing clinical signs of encephalitis in some Ebola patients at the Conakry EBOV Disease Treatment Centre in Guinea, the authors performed lumbar punctures on three of them:

  • A 32-year-old female sanitary technician whose signs and symptoms included headache, "ideomotor slowing without confusion," dizziness, gait instability, loss of inhibition, and inappropriate urination
  • A 27-year-old Guinean doctor who had headache, slow ideation, and aggression toward medical staff
  • A 28-year-old Guinean doctor who showed slow ideation, intolerance of frustration, aggressiveness, lack of inhibition, and "apragmatism"

The neurologic sings in all three patients improved by the third week of illness, and all three eventually were discharged.

The researchers said the patients' behavior changes and inappropriate attitudes were not accompanied by blood electrolyte imbalances, organ failure, sepsis, or any cause of metabolic encephalopathy. But it remains unclear, they added, whether the association of Ebola virus in the CSF with neurologic signs is sufficient to define a specific Ebola virus encephalitis.

"To improve the understanding of EBOV encephalitis, studies with neuropsychological examination and cerebral magnetic resonance imaging amongst surviving patients with follow-up are needed," the authors concluded.
Jul 14 Clin Infect Dis abstract

 

Sanofi study finds dengue vaccine reduces asymptomatic infections in kids

Sanofi Pasteur's tetravalent (four-strain) dengue vaccine reduces asymptomatic dengue infections in children 2 to 16 years old by about a third, which should help limit dengue transmission, according to a study by Sanofi researchers.

The authors, who reported their findings yesterday in the Journal of Infectious Diseases, wrote that an estimated 80% of all dengue infections are asymptomatic and that those who have such infections may serve as an important source of dengue transmission to mosquitoes and secondarily to humans.

The researchers used data from two phase 3 trials of the Dengvaxia vaccine that were conducted in Asia and Latin America. The data came from 3,736 participants who received three doses of either the vaccine or a placebo at 6-month intervals.

Seroconversion was used as a surrogate marker of asymptomatic dengue infection in both groups. It was defined as at least a fourfold increase in neutralizing antibody titer and a titer of at least 40 from months 13 through 25. This approach detected seroconversion in 94% of participants who were found to have virologically confirmed dengue between months 13 and 25, which validated the method, the authors said.

Among 3,369 participants who did not have virologically confirmed dengue, 8.8% (219 of 2,485) of the vaccine group and 13.3% (157 of 1,184) of the placebo group seroconverted between months 13 and 25. That translated into a vaccine efficacy (VE) of 33.5% (95% confidence interval [CI], 17.9% to 46.1%) against asymptomatic infection, the authors reported.

VE was higher in children 9 to 16 years old than in 2- to 8-year-olds: 38.6% (95% CI, 22.1%-51.5%) versus a nonsignificant 8.7% (95% CI, -50.7% to 43.5%).

By comparison, in a Latin American study, VE against virologically confirmed dengue in children ages 9 to 16 was found to be 60.8%, according to a New England Journal of Medicine report in 2015.

"The observed VE against asymptomatic dengue infections is expected to translate into reduced dengue virus transmission, if sufficient individuals are vaccinated in endemic areas," the authors concluded.
Jul 14 J Infect Dis report
Jan 8, 2015, N Engl J Med study

 

Prisons ripe for spread, but also for prevention, of HIV, hepatitis, and TB

The incidence of HIV, viral hepatitis, and tuberculosis (TB) is higher in incarcerated people, particularly in those who inject drugs, than in the general population across the world and could be reduced by such actions as decreasing prison rates for injection drug users and making available opioid agonist therapy for addicts, say the authors of a study published yesterday as part of a series in The Lancet.

The international group did a comprehensive review of literature published between 2005 to 2015 and modeled prison HIV transmission and the potential impact of preventive measures in that setting.

They estimated that of the 10.2 million people worldwide who in 2014 were incarcerated on any given day, 15.1% had hepatitis C virus infection, 4.8% had chronic hepatitis B virus infection, 3.8% had HIV, and 2.8% had active TB.

Drug injection is far more common in prison inmates than in the general population, a situation complicated by the fact that in many countries suspected drug users are detained in compulsory drug detention centers that operate outside of the judicial system, often "under the guise of drug treatment" but in reality providing little or no treatment for drug dependence or infectious diseases.

The situation could be improved, say the authors, by reducing the prison population. This could be accomplished through such policies as decriminalizing drug possession and use, making available evidence-based treatment for drug users both inside and outside of prisons, and putting users in settings other than prisons with more access to rehabilitation.

The study is one of six articles on HIV and related infections in prisoners, "an understudied and underserved population," published yesterday in The Lancet along with commentaries, a perspective, and a listing of related materials.
Jul 14 Lancet study
Jul 14 Lancet series

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