Lao People’s Democratic Republic (PDR) : 2015 Polio- 5th confirmed type 1 vaccine-derived poliovirus (VDPV) case

[Pathfinder]

Circulating vaccine-derived poliovirus – Lao People’s Democratic Republic

Disease outbreak news
12 October 2015

On 8 October 2015, the National IHR Focal Point of the Lao People’s Democratic Republic (PDR) notified WHO of one confirmed type 1 vaccine-derived poliovirus (VDPV) case.

Details of the case

In Lao PDR, one case of circulating vaccine-derived poliovirus type 1 (cVDPV1) was confirmed, with onset of paralysis on 7 September. The patient was 8 years old when he died on 11 September.

Genetic sequencing of the virus confirmed on 6 October that it is vaccine-derived and suggests that it has been circulating in the area for more than two years.

The child was in the district of Bolikhan, in Bolikhamxay Province. The district has chronically low immunization rates: reported coverage with 3 doses of oral polio vaccine (OPV) was of 40% to 66% between 2009 and 2014; and 44% in 2015 to date.

Lao’s last case of indigenous wild poliovirus was reported in 1993.

Public health response

Comprehensive outbreak response activities are taking place in response to this outbreak, in line with the Global Polio Eradication Initiative Standard Operating Procedures for responding to a poliovirus outbreak. A joint team of the Ministry of Health, the World Health Organization, UNICEF and the Lao Office of US Centers for Disease Control and Prevention team travelled to the province for further assessment on 7 October. A rapid survey conducted in the affected village showed low vaccine coverage for OPV. Active case finding in the surroundings of the case’s household is ongoing; stool specimens are being collected from healthy children in the case household and community.

Emergency Operations Centers (EOCs) at the national and province level have been activated to coordinate outbreak response activities. Preparations are under way for large-scale supplementary OPV immunization campaigns covering Bolikhamxay province and several adjacent provinces. The scope of additional campaigns will be ascertained following completion of the ongoing investigations.

WHO risk assessment

Circulating vaccine-derived polioviruses (cVDPVs) are rare but well-documented strains of poliovirus mutated from strains in oral polio vaccine (OPV). They can emerge in some populations that are inadequately immunized.

Ending polio for good requires eliminating both wild and vaccine-derived polio, and due to the risk of cVDPVs, use of OPV must be stopped to secure a lasting polio-free world. OPV will be withdrawn in a phased manner, beginning with the removal of type 2-containing OPV. The switch from trivalent to bivalent OPV, planned in April 2016, will reduce the risk of cVDPV substantially (as 90% of cVDPV is caused by type 2) and sets the stage to eventually stop using OPV altogether and transition to the inactivated polio vaccine (IPV), which cannot cause cVDPV.

Because of relatively limited travel to and from this area and the planned immunization activities , the World Health Organization (WHO) assesses the risk of international spread of the cVDPV1 from Lao to be low.

WHO advice

It is important that all countries, in particular those with frequent travel and contacts with polio-affected countries and areas, strengthen surveillance for acute flaccid paralysis (AFP) cases in order to rapidly detect any new virus importation and to facilitate a rapid response. Countries, territories and areas should also maintain uniformly high routine immunization coverage at the district level to minimize the consequences of any new virus introduction.

WHO’s International Travel and Health recommends that all travelers to polio-affected areas be fully vaccinated against polio. Residents (and visitors for more than 4 weeks) from infected areas should receive an additional dose of OPV or inactivated polio vaccine (IPV) within 4 weeks to 12 months of travel.

http://www.who.int/csr/don/12-october-2015-polio/en/

 

[Gert van der Hoek]

8-year-old boy dies of rare, vaccine-derived poliovirus in Laos

2015/10/12

The World Health Organization reported Monday that an 8-year-old boy in Laos became paralyzed from the poliovirus in early September and died five days later.
The case is believed to be the first infection in the country since 1993 and is part of an alarming reemergence of polio around the world in recent months. Ukraine and Mali -- two other countries where the virus was thought to have been wiped out -- also reported new cases of polio.

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[Gert van der Hoek]

Circulating vaccine-derived poliovirus ? Lao People?s Democratic Republic

Disease outbreak news

26 November 2015

Two additional cases of type 1 vaccine-derived poliovirus (VDPV1) have been reported from Lao People?s Democratic Republic (PDR), bringing the total number of cases in this outbreak to three.

Between 6 and 8 November 2015, the National IHR Focal Point of the Lao People?s Democratic Republic (PDR) notified WHO of 2 confirmed VDPV1 cases. Furthermore, circulating VDPV1 (cVDPV1) has also been isolated from the stools of 12 healthy contacts. All these contacts live in the same village, Bolikhan district (Bolikhamxay Province).

Details of the cases

The first of the new cases is a 15-year-old male. He comes from the same village as the first confirmed cVDPV1 case. He had no history of receiving oral polio vaccine (OPV). Considering that a nucleotide divergence of around 2.6% was detected between the isolate of the 15 year-old VDPV1 case and Sabin 1 strain, and considering that 3 close contacts tested positive for cVDPV1, the 15-year-old case was classified as a cVDPV1.

The second case is a 4-year-old male with onset of fever on 28 September and lower limb weakness on 29 September. On 1 October, the patient was admitted to the intensive care unit of Bolikhamxay Provincial Hospital, where he passed away on 2 October, before stool specimens could be collected. The patient was classified as an acute flaccid paralysis (AFP) case following retrospective review conducted at Bolikhamxay Provincial Hospital on 19 October. He had no history of receiving OPV. On 20 and 21 October, stool specimens were collected from 4 of his contacts, including household contacts and contacts from neighboring households; on 6 November, three of these contacts tested positive for cVDPV1. According to WHO criteria, the 4 year-old AFP case was therefore classified as a confirmed cVDPV1 case.

The National IHR Focal Point also provided an update on the investigation of contacts of the first confirmed cVDPV1 case (see DON published on 10 October). Stool samples from contacts were collected and cVDPV1 was isolated in 6 of them.

Previous to this outbreak, Bolikhan district had chronically low immunization rates: reported infant coverage with 3 doses of OPV was 40% to 66% between 2009 and 2014. Lao PDR?s last case of indigenous wild poliovirus occurred in 1993.

Public health response

Since the detection of the first confirmed cVDPV1 in Lao PDR, outbreak response activities have been conducted in three provinces, including the affected province (Bolikhamxay) and neighbouring provinces (Xaisounboun and Xiengkhuang). The national emergency operations centre has been activated to coordinate response efforts and a polio outbreak response plan was drafted. Enhanced surveillance is occurring throughout the country including daily zero-reporting of AFP cases. Active case finding is ongoing in the three provinces, including retrospective review of hospital and health centre records.

Six rounds with trivalent OPV vaccine have been planned from October 2015 to March 2016 (4 sub-national and 2 national) with ~ 8.6 million doses to be administered to children younger than 15 years. This age range was determined by the age distribution of the cases and their contacts. The first round of supplementary immunization activity (SIA) with OPV vaccine was completed in October in Bolikhamxay, Xaisounboun and Xiengkhuang provinces. Monitoring of October OPV SIA has occurred to identify areas with missed children and plan for mop-up activities. It is planned that this will continue during the next rounds to identify villages that require mop-up. Independent monitors were recruited to assess the quality of the campaigns.

To ensure the success of SIAs, emergency risk communications and social mobilization activities, including training of mobilizers and information sessions to build trust and address barriers to immunization, are being conducted. Key messages have been developed for radio and loudspeaker and are being translated to target identified communities.

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[Shiloh]

Source: http://outbreaknewstoday.com/laos-r...ived-poliovirus-case-unique-challenges-86834/


Laos reports 5th circulating vaccine-derived poliovirus case; unique challenges
Posted by Robert Herriman on December 6, 2015

A fifth case of circulating vaccine-derived poliovirus type 1 (cVDPV1) was reported in the Lao People?s Democratic Republic (Lao PDR) during the past week. The case was reported from Saysomboun district in Xaysomboune province, and had onset of paralysis on 28 October. This is the most recent date of onset, according to the Global Polio Eradication Initiative (GPEI)...

 

[Shiloh]

Source: http://www.who.int/csr/don/15-december-2015-polio-lao/en/

[h=1]Circulating vaccine-derived poliovirus ? Lao People?s Democratic Republic[/h] Disease outbreak news
15 December 2015

On 8 December 2015, the National IHR Focal Point of Lao People?s Democratic Republic (PDR) notified WHO of 2 additional VDPV1 cases. These cases are from Xaisomboun, a previously unaffected province. To date, the total number of confirmed cVDPV1 cases in this outbreak is 5.
[h=3]Details of the additional cases[/h] The first case is a 7 month-old male with an onset of paralysis on 3 October. He lives in Hom district, Xaisomboun province. The case received oral polio vaccine (OPV) on 30 September. On 4 November, stool samples were collected from 2 close contacts; both of these contacts tested positive for cVDPV1.
The second case is a 14-year-old male with onset of fever on 26 October and paralysis on 28 October. The case lives in Anouvong District, Xaisomboun Province. He has a history of receiving one OPV. On 6 and 7 November, stool specimens were collected from 3 of his contacts, including household contacts and contacts from neighboring households; 2 of these contacts tested positive for cVDPV1.
According to WHO criteria, these 2 cases of acute flaccid paralysis (AFP) are to be classified as confirmed cVDPV1 cases. In addition, circulating VDPV1 (cVDPV1) has also been isolated from the stools of 16 healthy contacts in Bolikhamxay and Xaisomboun Provinces since the beginning of the outbreak.
[h=3]Public health response[/h] Since the detection of the first confirmed cVDPV1 in Lao PDR, outbreak response activities have been conducted in the affected provinces (Bolikhamxay and Xaisoumboun) and a neighbouring province (Xiengkhuang). The national emergency operations centre was activated to coordinate response efforts and a polio outbreak response plan was drafted. Enhanced surveillance is occurring throughout the country, including daily zero-reporting of AFP cases. Active case finding is ongoing in the three provinces, including retrospective review of hospital and health centre records.
Six rounds with trivalent OPV vaccine have been planned from October 2015 to March 2016 (4 sub-national and 2 national) with ~ 8.6 million doses to be administered to children younger than 15 years. This age range was determined by the age distribution of the cases and their contacts. The first and second rounds of supplementary immunization activity (SIA) with OPV vaccine were completed in October and November in Bolikhamxay, Xaisoumboun and Xiengkhuang provinces. Independent monitors were recruited to assess the quality of the campaigns.
To ensure the success of SIAs, emergency risk communications and social mobilization activities, including training of mobilizers and information sessions to build trust and address barriers in the community to immunization, are being conducted.
[h=3]WHO risk assessment[/h] cVDPVs are rare but well-documented strains of poliovirus mutated from strains in OPV. They can emerge in some populations that are inadequately immunized. Ending polio requires eliminating both wild and vaccine-derived polio, and due to the small risk of cVDPVs, use of OPV must be stopped to secure a lasting polio-free world.
OPV will be withdrawn in a phased manner, beginning with the removal of type 2-containing OPV. The switch from trivalent to bivalent OPV, planned in April 2016, will reduce the risk of cVDPV substantially (as 90% of cVDPV is caused by type 2) and sets the stage to eventually stop using OPV altogether and transition to the inactivated polio vaccine (IPV), which cannot cause cVDPV.
Because of relatively limited travel to and from this area and the planned immunization activities, WHO assesses the risk of international spread of the cVDPV1 from Lao to be low.
[h=3]WHO advice[/h] It is important that all countries, in particular those with frequent travel and contacts with polio-affected countries and areas, strengthen surveillance for AFP cases in order to rapidly detect any new virus importation and to facilitate a rapid response. Countries, territories and areas should also maintain uniformly high routine immunization coverage at the district level to minimize the consequences of any new virus introduction.
WHO?s International Travel and Health recommends that all travelers to polio-affected areas be fully vaccinated against polio. Residents (and visitors for more than 4 weeks) from infected areas should receive an additional dose of OPV or IPV within 4 weeks to 12 months of travel.