Background Results Objectives Methodology

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Enteropathogen Distribution and Prevalence in Internally Displaced Persons Receiving an Oral Cholera Vaccine in South Sudan Peter  Hale1,  Malika  Bouhenia2,  Jesse  Bliss1,  Brianne  A.  Couturier3,  Anita  S.  Iyer1,  John  Rumunu4,  Stephen  MarAn5,     2 6 6,7 3 6 1   Abdinasir  Abubakar ,  David  Sack ,  Francisco  J.  Luquero ,  Marc  R.  Couturier ,  Andrew  S.  Azman ,  Daniel  T.  Leung 1University

of Utah, Salt Lake City, UT, United States, 2World Health Organization, Juba, South Sudan, 3ARUP Laboratories, Salt Lake City, UT, United States, 4Republic of South Sudan Ministry of Health, Juba, South Sudan, 5World Health Organization, Geneva, Switzerland, 6Johns Hopkins University, Baltimore, MD, United States, 7Epicentre, Paris, France  

Background

Pathogen presence and immune response:

Results

• Gastrointestinal infections are among the top killers of young children worldwide, accounting for more than 750,000 deaths a year1 • Previous studies have demonstrated a high burden of enteropathogen carriage among young children, even those without diarrhea, in lowincome countries.2 • Enteropathogen carriage has been associated with poor oral vaccine responses.3 • Data lacking regarding Enteropathogen carriage among those in refugee or Internally Displaced Person (IDP) camps

Objectives 1)  Describe the distribution of pathogens in stool of healthy oral cholera vaccine recipients in an internally displaced persons camp. 2)  Determine the relationship between pathogen carriage and immune responses to vaccine.

Methodology

!

1#5!yrs! (n=8)! 1" 2" 0" 0" 0" 0" 0" 0" 1" 0" 1" 0" 0" 2" 0" 0" 0" 0" 0" 7" 4"(50%)" 2"(25%)" 1"(13%)"

6#17!yrs! (n=27)! 4" 1" 3" 2" 1" 0" 0" 0" 1" 0" 7" 0" 0" 2" 0" 1" 0" 0" 0" 22" 13"(48%)" 7"(26%)" 1"(4%)"

18+!yrs! (n=51)! 1" 8" 2" 6" 3" 0" 1" 2" 2" 0" 3" 0" 1" 6" 0" 0" 0" 1" 0" 36" 22"(43%)" 10"(20%)" 3"(6%)"

Salmonella(spp.( Shigella(spp.( C.(jejuni/coli( STEC((stx1)(( STEC((stx2)( C.(upsiliensis( other(Campy(spp.( Cryptosporidium(spp.( Giardia(spp.( E.(histolytica( D.(fragilis( Cyclospora(spp.( Norovirus"GI" Norovirus"GII" Astrovirus" Adenovirus" Rotavirus" Sapovirus" V.(cholerae( Total(pathogens( ≥1(pathogens( ≥2(pathogens( ≥3(pathogens( " Table 1. Pathogen frequency by age group

Total! (n=86)! 6! 13! 5! 8! 4! 0! 1! 2! 4! 0! 11! 0! 1! 10! 0! 1! 0! 1! 0! 65! 39!(45%)! 19!(22%)! 5!(6%)!

Adenovirus (n=1)

Norovirus G1 (n=1)

proportion co−infected

Crypto (n=2)

1.00 0.75

• Bacterial pathogens (STEC, Shigella, Salmonella) among the most commonly carried o  Potential for outbreak in the overcrowded conditions of an IDP or refugee camp5

• Determine contribution of asymptomatic enteropathogen carriage on symptomatic disease and spread within IDP camps • Larger sample size to examine relationship between enteropathogen carriage and oral vaccine response

0.50

Campy (other) (n=1)

0.25 0.00 STX2 (n=4)

References 1.  Liu L, et al. 2012. Global, regional, and national causes of child mortality: an updated systematic analysis for 2010 with time trends since 2000. Lancet 379:2151-2161. 2.  Taniuchi M, et al. 2013. Etiology of Diarrhea in Bangladeshi Infants in the First Year of Life Analyzed Using Molecular Methods. J Infect Dis 208:1794-802. 3.  Parker EPK, et al. 2014. Influence of enteric infections on response to oral poliovirus vaccine: A systematic review and meta-analysis. J Infect Dis 210:853-64. 4.  Iyer AS, et al. Immune Responses to an Oral Cholera Vaccine in Internally Displaced Persons in South Sudan. Sci Rep. 6:35742. 5.  Lederer I, et al. 2015. Shigellosis in refugees, Austria, July to November 2015. Euro Surveill. 20:30081

STX1 (n=8)

Campy jejuni/coli(n=5)

Shigella (n=12)

Acknowledgements

co−infection

Figure 1. Pathogen co-occurrence patterns

Adenovirus

Norovirus G2

Norovirus G1

D. fragilis

Giardia

Crypto

Campy (other)

STX2

STX1

Campy jejuni/coli

Salmonella (n=6)

Shigella

•  Viruses:   •  Astrovirus   •  Norovirus  GI  and  GII   •  Adenovirus   •  Rotavirus   •  Sapovirus  

Giardia (n=4)

Salmonella

•  Parasites:   •  Cryptosporidium  spp.   •  Giardia  spp.   •  Dientamoeba  fragilis   •  Entamoeba  histoly8ca   •  Cyclospora  spp.  

• Nearly half (45%) of OCV recipients in an IDP camp in South Sudan had asymptomatic carriage of a detectable enteropathogen, and many with >1 pathogen o  Carriage rates similar among different age groups (young children, older children, and adults)

Future Directions

D. fragilis (n=11)

infection

•  Raw  stool  samples  shipped  from  Juba  to  Utah  on  dry  ice,  kept  at  -­‐80C   •  Stool  was  diluted  in  PBS  at  1:10  raAo  and  extracted  on  the  Chemagen   II  (Perkin  Elmer)  using  a  2x  Blood  Lysis  kit   •  Real-­‐Ame  PCR  was  performed  on  all  stool  for  the  following  targets:   •  Bacteria:   •  Salmonella  spp.   •  Shigella  spp.   •  Campylobacter  jejuni/coli/upsaliensis   •  STEC  (Stx1,  Stx2)   •  Campylobacter  lari/urely8cus/hyointes8nalis   •  Vibrio  cholerae  

Discussion/Conclusion

• Underpowered to determine impact of pathogen carriage on immunogenicity

Norovirus G2 (n=10)

Microbiological analysis

Table 2. No significant associations (by Fisher Exact test) between seroconversion and pathogens

Figure 2. Higher number of pathogens is associated with higher baseline vibriocidal titers for Inaba (p = 0.01) but not Ogawa. Note: Inaba was the circulating strain in year prior to sampling

• Baseline vibriocidal titer associated with higher pathogen carriage o  Enteropathogen carriage and exposures may be a marker for cholera risk

Sample Collection: •  IDP  camp  in  Juba,  South  Sudan   •  Stool  collected  from  individuals  enrolled  in  an  oral  cholera  vaccine   immunogenicity  study  in  20154   •  No  obvious  or  self-­‐reported  signs  of  acute  diarrheal  illness   •  Paired  stool  and  serum  samples  collected  pre-­‐vaccinaAon,  and  serum   samples  at  days  21  and  35  post-­‐vaccinaAon  

-  Baseline Inaba titer though not Ogawa associated with presence of enteric pathogens (Figure 2) -  Of 46 of subjects with two paired serum samples and baseline titer ≤80, 32 (70%) seroconverted (4-fold rise in vibricoidal titer)

The authors would like to thank the study staff, participants, community leaders in the UN House PoC, staff at the WHO Juba Country Office, IMC Staff (Dr Meroni Abraham, Alejandro Guzman, Kourtney Rusow, Emebet Dlasso). This work was sponsored by The National Institute of Health (K08 AI100923 grants to D.T.L, R01 AI106878 to E.T.R.), The Bill and Melinda Gates Foundation (OPP1089243 to A.S.A, Delivering Oral Vaccine Effectively (DOVE) Project, OPP153556 to D.A.S., F.J.L., A.S.A., and OPP 1089248 to WHO) and Margaret A Cargill Foundation grants to the WHO.