MERS studies explore risk of secondary cases, countermeasure progress
A preponderance of secondary MERS-CoV infections tend to occur in older and/or male relatives of a primary MERS patient and those with preexisting medical conditions, say findings of a study yesterday in Emerging Infectious Diseases (EID). Risk factors for household transmission included sleeping in the same room with a MERS patient and direct patient care.
The researchers, from the US Centers for Disease Control and Prevention (CDC) and institutions in Saudi Arabia, evaluated 79 members of the extended families in a cluster of five MERS-CoV (Middle East respiratory syndrome coronavirus) case-patients living in four households in 2014.
Interviews were done and questionnaires administered to determine such factors as exposure history, risk factors, recent travel, and underlying disease. Real-time reverse transcription polymerase chain reaction (rRT-PCR), the standard diagnostic method in Saudi Arabia, and serologic testing were also carried out.
Eleven of the 79 relatives were hospitalized for their illness, and 2 died.
Of the 79 relatives, 19 (24%) tested positive, 11 (58%) of whom had positive rRt-PCR results and 8 (42%) of whom had negative rRt-PCR but positive serology findings. Infected relatives were more likely than noninfected ones to be older and to have chronic medical conditions. Fifteen (83%) of the 19 infected relatives were male. The median age of family members with positive test results was 37, compared with 25 for those with negative results (P = 0.0011).
Risk factors for infection included sleeping in an index patient's room (relative risk [RR] = 4.1, 95% confidence interval [CI], 1.5-11.2), coming into contact with the patient's respiratory secretions (RR=4.0, 95% CI, 1.6-9.8), and removing the patient's biologic waste (RR=3.2, 95% CI, 1.2-8.4).
The authors note that because serologic testing proved to be more sensitive than rRT-PCR, the former should be included in future MERS-CoV investigations.
May 18 EID study on household transmission
In another MERS-CoV report yesterday in EID, the authors, from the CDC, Food and Drug Administration, and National Institutes of Health, say that although appreciable progress has been made on development of and research on medical countermeasures against the disease, the work to date is preliminary and the measures are not yet ready for clinical trials in humans.
The only such trial of a countermeasure so far is a phase 1 study of a candidate vaccine, they point out. Among the most pressing needs in terms of moving forward are prioritizing animal models, standardizing virus strains for study, developing diagnostics, improving access to nonhuman primates for preclinical testing, researching such control measures as human and camel vaccines, and developing a standardized clinical trial protocol, they say.
"Partnering with clinical trial networks in affected countries to evaluate safety and efficacy of investigational therapeutics will strengthen efforts to identify successful medical countermeasures," they conclude.
May 18 EID report on countermeasures
Risk factors for severe chikungunya, global distribution
The rare individuals infected so severely with chikungunya that they need to be treated in an intensive care unit (ICU) usually have preexisting medical conditions that are triggered by the disease, although some show severe manifestations specifically related to their infection, according to a study published yesterday in the International Journal of Infectious Diseases.
The French researchers analyzed the cases of 65 patients admitted to hospital ICUs with chikungunya infection in Guadeloupe and Martinique from January to November 2014. Fifty-four (83%) of them had an underlying disease, most commonly hypertension, diabetes, chronic heart failure, or renal failure.
Twenty-seven (41.5%) were admitted for an exacerbation of a comorbidity. Invasive mechanical ventilation was necessary in 37 (57%) of the patients, 30 (46%) needed vasoactive drugs, and 20 (31%) required renal replacement therapy.
Chikungunya-related manifestations, including central or peripheral neurologic disorder and severe sepsis or septic shock, occurred in 18 (28%) patients. Guillain-Barre syndrome was present in 6 (9%).
No appreciable difference in crude mortality rates was observed in the ICU patients compared with chikungunya patients hospitalized but not requiring ICU care (17 [26%) and 18 [27%], respectively).
May 18 Int J Infect Dis abstract
In other news, a report on global distribution of and environmental suitability for chikungunya in today's edition of Eurosurveillance says 94 countries have good evidence of the disease as well as a group of countries with the potential for spread of the disease. The authors estimate that 1.3 billion people live in at-risk areas.
The presence of Aedes aegypti mosquitoes, the vectors for human chikungunya, is a major contributing factor in terms of risk, although considerable geographic heterogeneity exist, say the authors. Their report contains high-resolution distribution maps modeled upon an occurrence data gathered from a variety of sources and environmental correlates.
May 19 Eurosurveill article
WHO details Lassa fever in Liberia, hemorrhagic fever in South Sudan
Yesterday and today the World Health Organization (WHO) posted notices on hemorrhagic fever illnesses in two different countries: Liberia, for its rise in Lassa fever cases, and South Sudan for a hemorrhagic fever syndrome outbreak.
Lassa fever in Liberia is endemic, and since Jan 1 the country has reported 38 suspected cases in six prefectures, the WHO said in a statement yesterday. Of 24 samples sent to Sierra Leone for testing, 7 were positive for Lassa fever. All were negative for Ebola.
Of the identified contacts, 134 have completed their 21-day monitoring periods, and 17 more people are still being followed. Given seasonal flare-ups this time of year, the WHO said further cases are expected, and it urged countries in West Africa to strengthen their surveillance systems.
May 18 WHO Liberia statement
Elsewhere, South Sudan since December has reported 51 cases in a suspected hemorrhagic fever syndrome outbreak, 10 of them fatal, the WHO said in a statement today. Two of the country's 28 counties are affected, both in the northwestern region, and three fourths of the patients are younger than 20 years old. No healthcare worker illnesses have been reported.
Typical symptoms are unexplained bleeding, fever, fatigue, headache, and vomiting. Symptoms are usually mild and resolve with supportive treatment, the WHO said.
So far tests on 33 samples have ruled out several viral hemorrhagic fever causes, including Ebola. Five samples were positive for Onyong-nyong virus, 3 were positive for chikungunya, and 1 was positive for dengue. Further testing is under way to pinpoint the source, which could also be bacterial or a foodborne toxin.
May 19 WHO South Sudan statement
Flu levels show early rise in parts of Southern Hemisphere
Brazil continues to report elevated seasonal flu activity, led by the 2009 H1N1 virus, and some other Southern Hemisphere are seeing levels starting to rise, including Ecuador and Bolivia, the WHO said in its latest global flu update.
Overall flu activity in Australia and New Caledonia are still low, but activity is starting to pick up in some Pacific locations, such as Fiji, American Samoa, and Micronesia. The Southern Hemisphere's flu season usually runs from May through October.
In the Northern Hemisphere, flu levels continue to taper off, with influenza B as the predominant strain, as is typical for this time of year. Areas still reporting elevated flu levels include El Salvador and Guatemala, both due to 2009 H1N1.
Africa's flu activity decreased in most locations, except for Egypt, where influenza B illnesses have increased in recent weeks.
Globally, influenza B was responsible for about 64% of detections, and of the subtyped influenza A viruses, nearly 82% were 2009 H1N1.
May 16 WHO global flu update
WHO: Maternal, neonatal tetanus eliminated from Southeast Asia
Maternal and neonatal tetanus has been eliminated from Southeast Asia, with all districts across the 11 countries in the region having reduced case numbers to less than 1 per 1,000 live births, the WHO announced today.
The status became official when the remaining pocket in the region—four provinces of Indonesia—achieved the target level for the disease, the agency said in a statement.
"The achievement demonstrates the commitment of countries in the Region to improve maternal and child health, especially neonatal health," said Poonam Khetrapal Singh, MD, WHO Southeast Asia regional director. "Tireless efforts of millions of health workers, who overcame huge challenges reaching out to vulnerable communities, and the support of the communities themselves, are invaluable contributions to achieving this goal."
Home to nearly a fourth of the world's population, the Southeast Asia Region is the second among six WHO regions to achieve tetanus elimination in moms and infants, after the European Region.
May 19 WHO statement