Study traces Ebola virus evolution in West African epidemic

A new genetic study of Ebola viruses in West Africa's epidemic, published yesterday in Nature, helps trace the disease's spread and, according to the authors, shows that the virus mutated at about the same rate observed in earlier outbreaks.

A large international team of researchers analyzed 179 Ebola virus sequences collected from patients in Guinea between March 2014 and January 2015. The researchers compared their genetic data with previously published findings.

The team identified several distinct Ebola lineages. An initial lineage A, linked to early Guinean cases starting in March 2014, remained mostly confined to Guinea and had faded by July. "This clade was likely to have been associated with the original outbreak in Guinea and was almost successfully contained in May 2014 by the interventions of the multi-agency response," the report states.

Lineage B emerged in May and June and was linked to two clusters of viruses from Sierra Leone. Early cases in both clusters "were both associated with a single funeral, so it is possible that this event may have reignited the epidemic," the report says. "Thereafter, lineage B spread into Guinea, Liberia and Sierra Leone. This lineage is associated with the large epidemics in these three countries and persisted into 2015."

In a press release from the University of Bristol, study leader Miles Carroll, PhD, said, "Our analysis shows the Ebola virus responsible for the current outbreak mutated at a similar rate to the earlier outbreaks in Uganda and the Democratic Republic of Congo.

"The results are good news for the scientists working to develop long-term solutions for Ebola, such as vaccines and treatments, as it means these new interventions should still work against the mutated strains of the virus." Carroll is director of research at Public Health England, Porton Down.
Jun 17 Nature letter
Jun 17 University of Bristol press release

NACCHO report notes 3,400 jobs lost in local health departments

Staffing cuts—though not as deep as in recent years—continue to plague local health departments (LHDs), and services have changed because of multiple factors, including budget cuts, according to data published today by the National Association of County and City Health Officials (NACCHO).

In its annual report on LHD staffing and services, called "Forces of Change," NACCHO found that 34% of agencies lost at least one staff person because of layoffs or attrition in 2014, with job cuts totaling 3,400. That is down from a high of 16,000 in 2009 and the lowest since belt-tightening began in 2008, but LHD positions lost since 2008 now total 51,700. Job losses in 2012 and 2013 were 4,300 and 4,400, respectively.

The figures reflect self-reported data from 690 LHDs surveyed across the country (out of 948 contacted, for a 73% return rate). NACCHO generated national statistics using estimation weights to account for sampling and non-response, the group said in the report.

The report also notes budget stagnation for LHDs. About 23% reported budget cuts, while 21% reported budget increases, with the rest reporting flat budgets. But only 16% of large LHDs—which collectively serve almost half the US population—saw budget increases, down from 21% the year before.

Changes in services provided gave a mixed picture. Although 36% of LHDs reduced at least one program area, 53% expanded at least one area.

In general, reductions in clinical services slightly outpaced expansions. For example, 14% of LHDs reduced immunization programs, while 12% expanded them. Screening or treatment for communicable diseases, in contrast, decreased in 3% of LHDs but increased in 12%.

Population-based services, however, tended to expand. Emergency preparedness, for example, decreased in only 6% of LHDs while increasing in 16%. And only 3% of LHDs reduced epidemiology and surveillance, compared with 10% that increased such services.

The report also noted some effects of the Affordable Care Act, such as 38% of LHDs serving more people who have insurance.
Jun 18 NACCHO report

Invading mosquitoes in California boost risk of dengue, chikungunya

California faces a growing, though still low, risk of dengue and chikungunya virus transmission in view of the presence of the viruses' two principal mosquito vectors in the state, according to a new report in Emerging Infectious Diseases.

In 2011, Aedes albopictus mosquitoes were detected in El Monte, a city in Los Angeles County, says the report by researchers from the California Department of Public Health (CDPH). Since then, the species has persisted and spread to 12 other neighboring cities.

The other vector species, A aegypti, was found in 2013 in Fresno, Madera, and San Mateo counties. In 2014, the mosquitoes persisted in those three counties and also surfaced in Kern, Tulare, Los Angeles, and San Diego counties. This year the species has been found in Imperial, Orange, and Alameda counties. None of 1,729 A aegypti mosquitoes that were tested, however, were carrying dengue or chikungunya virus.

In 2014, 141 chikungunya fever and 133 dengue cases were reported in California, all in people who had recently traveled to places with dengue or chikungunya activity. Of the 133 dengue case-patients, 98 (74%) were probably viremic while in California, and the same was true for 93 (66%) of the 141 chikungunya case-patients.

"Of these likely viremic patients, 44% (43/98) with dengue and 58% (54/93) with chikungunya fever arrived or returned to a county with an infestation of invasive Aedes mosquitoes and, thus, represented a potential risk for virus transmission if bitten," the report states.

The authors say the risk of local transmission of the two viruses is still low because returning infected travelers are few and the mosquitoes' distribution is limited. But the threat is growing as travel increases and is of particular concern in southern California because of its large population, high travel volume, and nearness to Mexico, where dengue is more common.

To counter the threat, the CDPH has distributed guidance to local public health and vector-control agencies to enhance human case and mosquito surveillance, increase awareness of the diseases, and promote Aedes mosquito control measures.
Jun 17 Emerg Infect Dis report

Studies: Faster polio vaccine timing doesn't cut immune response

Two studies today in The Lancet Infectious Diseases, conducted in Pakistan and Bangladesh, showed that doses of oral polio vaccine (OPV) given in more rapid succession than usual result in a similar immune response, indicating new possibilities for immunization campaigns.

OPV doses are usually spaced 4 weeks or more apart unless security or other reasons warrant a tighter timetable. In Pakistan, 829 babies who had received trivalent OPV at birth were randomly assigned to receive two doses of type-1 monovalent OPV (mOPV1) at either 1-week, 2-week, or 4-week intervals, or two doses of bivalent OPV (bOPV) with 4 weeks between doses.

In the Bangladeshi trial, 927 infants received a short three-dose schedule of bOPV or mOPV1 at age 6 weeks, 8 weeks, and 10 weeks or a standard three-dose schedule of bOPV or mOPV1 at age 6 weeks, 10 weeks, and 14 weeks.

Both studies found immune responses to be similar with the compact timeline compared with standard dose spacing.

In a related commentary, Nicholas C. Grassly, DPhil, said the studies "support the use of short-interval campaigns with other strategies to maximise the immunogenicity of each vaccination contact with children in Pakistan," a nation that has seen sporadic violence against vaccination teams.

He added, "The trials therefore also provide evidence to support the regulatory approval and licensing of bOPV on this schedule," which is important for ongoing polio-control efforts. Grassly is with Imperial College London and Christian Medical College in India.
Jun 17 Lancet Infect Dis Pakistan study
Jun 17 Lancet Infect Dis Bangladesh study
Jun 17 Lancet Infect Dis related commentary

Cholera outbreak in Tanzania prompts vaccination drive

With a cholera outbreak in a large refugee camp in western Tanzania spilling over into local villages, plans are afoot to provide oral cholera vaccine to all the refugees and to residents of surrounding areas, the World Health Organization's (WHO's) Regional Office for Africa announced today.

Since the outbreak began on May 10, 4,662 suspected or confirmed cases and 34 deaths have been reported, the WHO said. The numbers include 129 cases and 3 deaths among Tanzanians.

A daily influx of asylum seekers has caused the population in the Nyarugusu camp in Tanzania's Kigoma region to swell to over 55,500, the WHO said.

The WHO and its partners are providing 164,500 doses of cholera vaccine for the immunization campaign, which was announced Jun 15. Plans call for providing the vaccine to all residents of the refugee camp and to 54,110 people living nearby.

Regional authorities said the provision of safe water, sanitation, and personal hygiene will continue to be the main cholera prevention and control measures.
Jun 18 WHO statement

In related news, WHO Africa said yesterday it has been working with South Sudan's Ministry of Health to step up cholera preparedness and surveillance with the aim of preventing a repeat of last year's large cholera outbreak in the country.

Just one cholera case, in Juba, has been reported recently, compared with 6,421 cases and 167 deaths in an outbreak that began in May of last year, the agency said. The recent case was at a United Nations House Protection of Civilians site, where internally displaced persons are sheltered. More than 28,000 people live at such sites in the country.

Preparedness efforts have included providing diagnostic test kits and other supplies and updating cholera contingency plans, the WHO said. In addition, the agency has begun a series of oral vaccination campaigns in parts of the country.
Jun 17 WHO statement