Volume 83, Issue 3
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



A prospective hospital-based study was undertaken to define the incidence of invasive pneumococcal disease (IPD) and circulating serotypes in Laos. Of 10,799 patients with hemocultures and 353 patients with cerebrospinal fluid samples, 0.21% and 5.4%, respectively, were positive for , giving a total of 35 IPD patients. We developed a real-time polymerase chain reaction to detect serotypes represented in the 13-valent pneumococcal vaccine. A blinded evaluation comparing serotype as defined by the Quellung reaction versus the polymerase chain reaction demonstrated 100% concordance. The most frequent serotype (n = 33 patients) was 1 (n = 6), followed by serotypes 5, 6A/B/C, 14, and 23F. Serotypes represented in the 7-valent polysaccharide-protein conjugate vaccine (PCV-7) infected 39% of patients, with 73% coverage for the PCV-10 and PCV-13 vaccines. Although the sample size is small, these data suggest that the PCV-7 vaccine may have relatively low efficacy in Laos. Further studies are urgently needed to guide pneumococcal vaccine policy in Laos.


Article metrics loading...

Loading full text...

Full text loading...



  1. World Health Organization WHO, 2003. WHO-Recommended Standards for Surveillance of Selected Vaccine-Preventable Diseases, Vaccine Assessment and Monitoring Team of the Department of Vaccines and Biologicals. Available at: http://www.who.int/vaccines-documents/DocsPDF06/843.pdf. Accessed May 15, 2009.
  2. Hsu HE, Shutt KA, Moore MR, Beall BW, Bennett NM, Craig AS, Farley MM, Jorgensen JH, Lexau CA, Petit S, Reingold A, Schaffner W, Thomas A, Whitney CG, Harrison LH, , 2009. Effect of pneumococcal conjugate vaccine on pneumococcal meningitis. N Engl J Med 360: 244256.[Crossref]
  3. Whitney CG, Farley MM, Hadler J, Harrison LH, Bennett NM, Lynfield R, Reingold A, Cieslak PR, Pilishvili T, Jackson D, Facklam RR, Jorgensen JH, Schuchat A, , 2003. Decline in invasive pneumococcal disease after the introduction of protein-polysaccharide conjugate vaccine. N Engl J Med 348: 17371746.[Crossref]
  4. Cutts FT, Zaman SM, Enwere G, Jaffar S, Levine OS, Okoko JB, Oluwalana C, Vaughan A, Obaro SK, Leach A, McAdam KP, Biney E, Saaka M, Onwuchekwa U, Yallop F, Pierce NF, Greenwood BM, Adegbola RA, , 2005. Efficacy of nine-valent pneumococcal conjugate vaccine against pneumonia and invasive pneumococcal disease in The Gambia: randomised, double-blind, placebo-controlled trial. Lancet 365: 11391146.[Crossref]
  5. Klugman KP, Madhi SA, Huebner RE, Kohberger R, Mbelle N, Pierce N, , 2003. A trial of a 9-valent pneumococcal conjugate vaccine in children with and those without HIV infection. N Engl J Med 349: 13411348.[Crossref]
  6. Scott JA, , 2007. The preventable burden of pneumococcal disease in the developing world. Vaccine 25: 23982405.[Crossref]
  7. Grijalva CG, Edwards KM, , 2006. Promises and challenges of pneumococcal conjugate vaccines for the developing world. Clin Infect Dis 43: 680682.[Crossref]
  8. Lucero MG, Nohynek H, Williams G, Tallo V, Simoes EA, Lupisan S, Sanvictores D, Forsyth S, Puumalainen T, Ugpo J, Lechago M, de Campo M, Abucejo-Ladesma E, Sombrero L, Nissinen A, Soininen A, Ruutu P, Riley I, Makela HP, , 2009. Efficacy of an 11-valent pneumococcal conjugate vaccine against radiologically confirmed pneumonia among children less than 2 years of age in the Philippines: a randomized, double-blind, placebo-controlled trial. Pediatr Infect Dis J 28: 455462.[Crossref]
  9. Hausdorff WP, Bryant J, Paradiso PR, Siber GR, , 2000. Which pneumococcal serogroups cause the most invasive disease: implications for conjugate vaccine formulation and use, part I. Clin Infect Dis 30: 100121.[Crossref]
  10. Hausdorff WP, Bryant J, Kloek C, Paradiso PR, Siber GR, , 2000. The contribution of specific pneumococcal serogroups to different disease manifestations: implications for conjugate vaccine formulation and use, part II. Clin Infect Dis 30: 122140.[Crossref]
  11. UNICEF, 2007. UNICEF Website Demographics; At a Glance: Lao People's Democratic Republic. Statistics. Available at: http://www.unicef.org/infobycountry/laopdr_statistics.html. Accessed June 20, 2009.
  12. Phetsouvanh R, Phongmany S, Soukaloun D, Rasachak B, Soukhaseum V, Soukhaseum S, Frichithavong K, Khounnorath S, Pengdee B, Phiasakha K, Chu V, Luangxay K, Rattanavong S, Sisouk K, Keolouangkot V, Mayxay M, Ramsay A, Blacksell SD, Campbell J, Martinez-Aussel B, Heuanvongsy M, Bounxouei B, Thammavong C, Syhavong B, Strobel M, Peacock SJ, White NJ, Newton PN, , 2006. Causes of community-acquired bacteremia and patterns of antimicrobial resistance in Vientiane, Laos. Am J Trop Med Hyg 75: 978985.
  13. Carvalho Mda G, Tondella ML, McCaustland K, Weidlich L, McGee L, Mayer LW, Steigerwalt A, Whaley M, Facklam RR, Fields B, Carlone G, Ades EW, Dagan R, Sampson JS, , 2007. Evaluation and improvement of real-time PCR assays targeting lytA, ply, and psaA genes for detection of pneumococcal DNA. J Clin Microbiol 45: 24602466.[Crossref]
  14. Cheeseborough M, , 2006. District Laboratory Practice in Tropical Countries. Volume 2. Cambridge, United Kingdom: Cambridge University Press.[Crossref]
  15. Austrian R, , 1976. The quellung reaction, a neglected microbiologic technique. Mt Sinai J Med 43: 699709.
  16. Clinical and Laboratory Standards Institute, 2009. Performance Standards for Antimicrobial Disk Susceptibility Tests; Approved Standard, Tenth Edition. Approved Standard M02-A10. Wayne, PA: Clinical and Laboratory Standards Institute.
  17. Clinical and Laboratory Standards Institute, 2009. Performance Standards for Antimicrobial Susceptibility Testing. Nineteenth International (Supplement): M100–S19. Wayne, PA: Clinical and Laboratory Standards Institute.
  18. Ikejima H, Haranaga S, Takemura H, Kamo T, Takahashi Y, Friedman H, Yamamoto Y, , 2001. PCR-based method for isolation and detection of Chlamydia pneumoniae DNA in cerebrospinal fluids. Clin Diagn Lab Immunol 8: 499502.
  19. Corless CE, Guiver M, Borrow R, Edwards-Jones V, Fox AJ, Kaczmarski EB, , 2001. Simultaneous detection of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae in suspected cases of meningitis and septicemia using real-time PCR. J Clin Microbiol 39: 15531558.[Crossref]
  20. Parry CM, Diep TS, Wain J, Hoa NT, Gainsborough M, Nga D, Davies C, Phu NH, Hien TT, White NJ, Farrar JJ, , 2000. Nasal carriage in Vietnamese children of Streptococcus pneumoniae resistant to multiple antimicrobial agents. Antimicrob Agents Chemother 44: 484488.[Crossref]
  21. Baggett HC, Peruski LF, Olsen SJ, Thamthitiwat S, Rhodes J, Dejsirilert S, Wongjindanon W, Dowell SF, Fischer JE, Areerat P, Sornkij D, Jorakate P, Kaewpan A, Prapasiri P, Naorat S, Sangsuk L, Eampokalap B, Moore MR, Carvalho G, Beall B, Ungchusak K, Maloney SA, , 2009. Incidence of pneumococcal bacteremia requiring hospitalization in rural Thailand. Clin Infect Dis 48 (Suppl 2): S65S74.[Crossref]
  22. Bogaert D, Ha NT, Sluijter M, Lemmens N, De Groot R, Hermans PW, , 2002. Molecular epidemiology of pneumococcal carriage among children with upper respiratory tract infections in Hanoi, Vietnam. J Clin Microbiol 40: 39033908.[Crossref]
  23. Watanabe H, Asoh N, Hoshino K, Watanabe K, Oishi K, Kositsakulchai W, Sanchai T, Kunsuikmengrai K, Kahintapong S, Khantawa B, Tharavichitkul P, Sirisanthana T, Nagatake T, , 2003. Antimicrobial susceptibility and serotype distribution of Streptococcus pneumoniae and molecular characterization of multidrug-resistant serotype 19F, 6B, and 23F pneumococci in northern Thailand. J Clin Microbiol 41: 41784183.[Crossref]
  24. Srifeungfung S, Chokephaibulkit K, Tribuddharat C, , 2007. Serotypes and antimicrobial susceptibilities of Streptococcus pneumoniae isolated from hospitalized patients in Thailand. Southeast Asian J Trop Med Public Health 38: 469477.
  25. Song JH, Lee NY, Ichiyama S, Yoshida R, Hirakata Y, Fu W, Chongthaleong A, Aswapokee N, Chiu CH, Lalitha MK, Thomas K, Perera J, Yee TT, Jamal F, Warsa UC, Vinh BX, Jacobs MR, Appelbaum PC, Pai CH, , 1999. Spread of drug-resistant Streptococcus pneumoniae in Asian countries: Asian Network for Surveillance of Resistant Pathogens (ANSORP) Study. Clin Infect Dis 28: 12061211.[Crossref]
  26. Batuwanthudawe R, Karunarathne K, Dassanayake M, de Silva S, Lalitha MK, Thomas K, Steinhoff M, Abeysinghe N, , 2009. Surveillance of invasive pneumococcal disease in Colombo, Sri Lanka. Clin Infect Dis 48 (Suppl 2): S136S140.[Crossref]
  27. Xue L, Yao K, Xie G, Zheng Y, Wang C, Shang Y, Wang H, Wan L, Liu L, Li C, Ji W, Xu X, Wang Y, Xu P, Liu Z, Yu S, Yang Y, , 2010. Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae isolates that cause invasive disease among Chinese children. Clin Infect Dis 50: 741744.[Crossref]
  28. Shah AS, Knoll MD, Sharma PR, Moisi JC, Kulkarni P, Lalitha MK, Steinhoff M, Thomas K, , 2009. Invasive pneumococcal disease in Kanti Children's Hospital, Nepal, as observed by the South Asian Pneumococcal Alliance network. Clin Infect Dis 48 (Suppl 2): S123S128.[Crossref]
  29. Phongsamart W, Srifeungfung S, Dejsirilert S, Chatsuwan T, Nunthapisud P, Treerauthaweeraphong V, Rungnobhakhun P, Chokephaibulkit K, , 2007. Serotype distribution and antimicrobial susceptibility of S. pneumoniae causing invasive disease in Thai children younger than 5 years old, 2000–2005. Vaccine 25: 12751280.[Crossref]
  30. Levine OS, Cherian T, Hajjeh R, Knoll MD, , 2009. Progress and future challenges in coordinated surveillance and detection of pneumococcal and Hib disease in developing countries. Clin Infect Dis 48 (Suppl 2): S33S36.[Crossref]
  31. Anh DD, Kilgore PE, Slack MP, Nyambat B, Tho le H, Yoshida LM, Nguyen HA, Nguyen CD, Chong CY, Nguyen D, Ariyoshi K, Clemens JD, Jodar L, , 2009. Surveillance of pneumococcal-associated disease among hospitalized children in Khanh Hoa Province, Vietnam. Clin Infect Dis 48 (Suppl 2): S57S64.[Crossref]
  32. Pai R, Gertz RE, Beall B, , 2006. Sequential multiplex PCR approach for determining capsular serotypes of Streptococcus pneumoniae isolates. J Clin Microbiol 44: 124131.[Crossref]
  33. Brito DA, Ramirez M, de Lencastre H, , 2003. Serotyping Streptococcus pneumoniae by multiplex PCR. J Clin Microbiol 41: 23782384.[Crossref]
  34. Saha SK, Darmstadt GL, Baqui AH, Hossain B, Islam M, Foster D, Al-Emran H, Naheed A, Arifeen SE, Luby SP, Santosham M, Crook D, , 2008. Identification of serotype in culture negative pneumococcal meningitis using sequential multiplex PCR: implication for surveillance and vaccine design. PLoS One 3: e3576.[Crossref]
  35. Hare KM, Smith-Vaughan H, Binks M, Park IH, Nahm MH, Leach AJ, , 2009. “Dodgy 6As”: differentiating pneumococcal serotype 6C from 6A by use of the Quellung reaction. J Clin Microbiol 47: 19811982.[Crossref]
  36. Jin P, Xiao M, Kong F, Oftadeh S, Zhou F, Liu C, Gilbert GL, , 2009. A simple, accurate serotype-specific PCR assay to differentiate Streptococcus pneumoniae serotypes 6A, 6B and 6C. J Clin Microbiol 47: 24702474.[Crossref]
  37. Jacobs MR, Bajaksouzian S, Bonomo RA, Good CE, Windau AR, Hujer AM, Massire C, Melton R, Blyn LB, Ecker DJ, Sampath R, , 2009. Occurrence, distribution, and origins of Streptococcus pneumoniae serotype 6C, a recently recognized serotype. J Clin Microbiol 47: 6472.[Crossref]
  38. Carvalho Mda G, Pimenta FC, Gertz RE, Jr Joshi HH, Trujillo AA, Keys LE, Findley J, Moura IS, Park IH, Hollingshead SK, Pilishvili T, Whitney CG, Nahm MH, Beall BW, , 2009. PCR-based quantitation and clonal diversity of the current prevalent invasive serogroup 6 pneumococcal serotype, 6C, in the United States in 1999 and 2006 to 2007. J Clin Microbiol 47: 554559.[Crossref]
  39. Weinberger DM, Dagan R, Givon-Lavi N, Regev-Yochay G, Malley R, Lipsitch M, , 2008. Epidemiologic evidence for serotype-specific acquired immunity to pneumococcal carriage. J Infect Dis 197: 15111518.[Crossref]

Data & Media loading...

  • Received : 19 Apr 2010
  • Accepted : 12 May 2010

Most Cited This Month

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error