Tuesday, May 09, 2017

CIDRAP: Meningitis Suspected In Liberian Outbreak
















#12,441


A week ago the cause of the deadly outbreak of disease linked to a funeral gathering in Sinoe county, Liberia on the 23rd of April was still unknown - but thought to be likely due to food poisoning or some other non-communicable ingested toxin (see WHO Update & Summary On Liberia Outbreak Of Unknown Eitiology). 


Meningitis suspected in Liberia's mystery illness outbreak
Filed Under: Meningitis
Lisa Schnirring | News Editor | CIDRAP News |
May 08, 2017

Test results from samples of four Liberians who are part of an unexplained illness cluster suggests meningitis as a possible cause, apparently shifting suspicious away from point-source contamination of food, drink, or water.

Bernice Dahn, MD, MPH, the country's health minister, announced at a media briefing in Monrovia today that seven specimens from people who died from the disease were positive for Neisseria meningitidis, Reuters reported.

She said that, based on initial results from the US Centers for Disease Control and Prevention (CDC), Liberian health officials believe that the unexplained illness cluster reflects a probable meningitis outbreak in Sinoe County that spread to Montserrado and Grand Bassa counties.

Dahn said public health officials are exploring the possibility of mass vaccination and that more lab tests are under way. She put the outbreak total at 31 cases, 13 of them fatal, which reflects an increase of 3 more cases and 1 more death.

(Continue . . . )
 
Although literally surrounded by countries that make up the sub-Saharan `Meningitis belt' (see map above), Liberia has never been considered a hotbed of the disease. 

From the CDC's Yellow Book:

Meningococcal Disease

Jessica R. MacNeil, Sarah A. Meyer 
INFECTIOUS AGENT

Neisseria meningitidis is a gram-negative diplococcus. Meningococci are classified into serogroups on the basis of the composition of the capsular polysaccharide. The 6 major meningococcal serogroups associated with disease are A, B, C, W, X, and Y. 


TRANSMISSION

Person-to-person transmission occurs by close contact with respiratory secretions or saliva. 


EPIDEMIOLOGY


N. meningitidis is found worldwide, but the highest incidence is in the “meningitis belt” of sub-Saharan Africa (Map 3-11). Meningococcal disease is hyperendemic in this region, and periodic epidemics during the dry season (December–June) reach up to 1,000 cases per 100,000 population. By contrast, rates of disease in the United States, Europe, Australia, and South America range from 0.3 to 3 cases per 100,000 population per year. Although most common in the African meningitis belt, meningococcal outbreaks can occur anywhere in the world. Serogroup A predominates in the meningitis belt, although serogroups C, X, and W are also found. At any time, 5%–10% of the population may be carriers of N. meningitidis.

Outside the meningitis belt, infants have the highest rates of disease. In meningitis belt countries, high attack rates are seen up to 30 years of age. Risk for travelers is highest in people visiting meningitis belt countries who have prolonged contact with local populations during an epidemic. The Hajj pilgrimage to Saudi Arabia has also been associated with outbreaks of meningococcal disease in returning pilgrims and their contacts.

A monovalent serotype A vaccine (MenAfriVac, Serum Institute of India) came into widespread use in Africa's meningitis belt in 2010, and the yearly incidence of meningitis has declined.
But as serotype A has diminished, serotype C has begun to flourish in the region.
The current recommendations (from the CDC's Yellow Book) for travelers to regions where meningitis is endemic is for the vaccination by the quadrivalent meningococcal vaccine. 
Travelers who visit or reside in countries where meningococcal disease is hyperendemic or epidemic, including the meningitis belt of sub-Saharan Africa during the dry season (December–June), should receive vaccination with a quadrivalent meningococcal vaccine, either MenACWY vaccine (people aged 2 months through 55 years and meningococcal vaccine non-naïve people aged ≥56 years) or MPSV4 (meningococcal vaccine-naïve people aged ≥56 years) before travel. Infants and children who received Hib-MenCY-TT are not protected against serogroups A and W and should receive a quadrivalent vaccine before travel if traveling to areas with high endemic rates of meningococcal disease.


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