13 November 2007

Cluster of Yellow Fever Vaccine Associated Viscerotropic Disease, Peru

Four fatal cases of adverse events in Peru following receipt of yellow fever vaccine (YFV) manufactured by Bio-Manguinhos, Brazil, have been reported by the Pan American Health Organization (PAHO) and the World Health Organization (WHO) [1].

The four deaths occurred in Peru between 7 and 24 October 2007 in persons ranging in age from 23 to 79 years. They had received YFV as part of an emergency vaccination programme in the Ica region, south of Lima following the earthquake in August 2007. All cases had received YFV from a single lot (050VFA121Z). The use of this lot and production lots related to it, have been suspended.

The cases had a similar clinical picture of fever, headache, malaise and diarrhoea, progressing rapidly to shock and multiple organ failure. The onset of symptoms ranged from less than a day to one week following vaccination. Three of the four cases have been laboratory confirmed as YFV associated acute viscerotropic disease (AVD); the fourth case is classified as probable pending additional laboratory testing.

The national authorities in Peru along with support from PAHO, WHO and the Centers for Disease Control and Prevention, and other experts in yellow fever are reviewing all of the information related to these cases, including laboratory testing of vaccine samples.

Advice for Travellers

The risk of severe adverse events following YFV is rare. Based on current information, the risk of YFV associated AVD is in the order of 0.3 to 0.5 cases per 100,000 doses with a higher risk in those aged 60 years and older. The risk of YFV associated AVD in this cluster of cases following receipt of the Brazilian manufactured vaccine is about 10 cases per 100,000 doses, 20 fold higher.

There is no indication that any lots of the Brazilian vaccine are in use in the United Kingdom. Therefore, there is no specific action that UK health providers need to take regarding this cluster of cases. Nevertheless, a careful risk assessment should be undertaken by all health practitioners before administering vaccine. Specific country guidance on yellow fever vaccine risk and requirements can be found on the NaTHNaC Country Information Pages: http://www.nathnac.org/ds/map_world.aspx  

Reference

Statement by the Pan American Health Organization/World Health Organization. Fatal adverse events following receipt of yellow fever vaccine produced by Bio-Manguinhos, Brazil. 2 Novemebr 2007. Accessed 14 November 2007. Available at: http://www.who.int/immunization_safety/aefi/investigations_yello

w_fever_Peru_2Nov07/en/index.html 

Yellow fever. In: Centers for Disease Control and Prevention.  Health Information for International Travel 2008.  2007, Atlanta: US Department of Health and Human Services, Public Health Service. pp. 362-79. Available at: http://wwwn.cdc.gov/travel/yellowBookCh4-YellowFever.aspx.

Links

NaTHNaC Health Information Sheet on Yellow Fever