Lassa fever is Viral Hemorrhagic Fever (VHF) endemic to a number of West African nations, commonly carried by multimammate rats, a local rodent that often likes to enter human dwellings. Exposure is typically through the urine or dried feces of infected rodents, and roughly 80% who are infected only experience mild symptoms.
The overall mortality rate is believed to be in the 1%-2% range, although it runs much higher (15%-20%) among those sick enough to be hospitalized. Like many other hemorrhagic fevers, person-to-person transmission may occur with exposure to the blood, tissue, secretions, or excretions of an individual, although the CDC reassures:
Casual contact (including skin-to-skin contact without exchange of body fluids) does not spread Lassa virus. Person-to-person transmission is common in health care settings (called nosocomial transmission) where proper personal protective equipment (PPE) is not available or not used. Lassa virus may be spread in contaminated medical equipment, such as reused needles.Very occasionally we see exported cases, and in 2016 we followed cases in Germany and Sweden (see Germany's RKI Statement On Lassa Fever Cluster In Cologne & WHO Lassa Fever Update - Sweden (Imported)).
In the spring of 2016 West Africa reported an unusually high number of Lassa Fever cases. Nigeria's most recent CDC weekly epidemiological record (week 29 -2017) shows this year's numbers running about half of last year's.
Between weeks 1 and 29 (2017), 344 suspected Lassa fever cases with 86 laboratory confirmed cases and 56 deaths (CFR, 16.28%) from 67 LGAs (22 States) were reported compared with 746 suspected cases with 72 laboratory confirmed cases and 87 deaths (CFR, 11.66%) from 127 LGAs (27 States) during the same period in 2016 (Figure 1).Over the past several days, however, Nigerian media has been reporting on several cases hospitalized in Lagos, and the most recent reports indicate 3 HCWs at LUTH (Lagos University Teaching Hospital) have been infected, and 150 potentially exposed staff are under watch..
Lassa fever: 3 more test positive at LUTH, 150 under watch(Continue . . . )
By Sola Ogundipe, Chioma Obinna & Gabriel Olawale
LAGOS—Three persons under surveillance for Lassa fever at the Lagos University Teaching Hospital, LUTH, have tested positive to the disease.
This came as Lagos State Government, yesterday, urged Lagosians not to panic, saying the epidemic was near containment in the state. Also, 150 people exposed to the cases are now under surveillance.
Meanwhile, as part of efforts to contain the spread of the contagious disease, the Lagos State Government has taken over the burial of the corpse of the second index case at LUTH.
Disclosing these and other developments in a joint press conference of LUTH and Lagos State Ministry of Health, the Chief Medical Director, Prof Chris Bode, explained that the current outbreak was being effectively traced in the field, adding that all persons currently exposed to the index cases were being effectively treated.
Although I can find nothing specific on the Nigerian CDC website about this LUTH outbreak, they did post the following yesterday on their twitter account.
While Lassa fever infections are not uncommon in Nigeria, and outbreaks tend to be small and self-limiting - the fact that this is happening at a large University Hospital in one of the world's most populous cities - makes this event worth keeping one eye on.