Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 15, Number 3—March 2009
Letter

Hypothetical Pneumocystis jirovecii Transmission from Immunocompetent Carriers to Infant

Cite This Article

To the Editor

The recent dispatch article by Rivero et al. reports the transmission of Pneumocystis jirovecii from immunocompetent grandparents to their granddaughter (1). The authors’ conclusion was based on 2 facts: the grandparents were carriers but neither the parents nor the child’s brother was a carrier, and the P. jirovecii genotype observed in the grandparents was identical to that found in the infant. In our opinion, the data provided by the authors do not support the conclusion that transmission has occurred. First, the 2 markers used for typing show a small number of alleles and thus provide low discrimination among isolates (2). Consequently, the P. jirovecii isolates present in the grandparents and in the infant may have been epidemiologically unrelated. Second, the frequency of occurrence of the different genotypes obtained was not investigated. The presence of the same genotype in the grandparents and in the infant may result from a high frequency of this genotype in the geographic area where the family lived. In fact, the use of a validated typing method and the analysis of unlinked control patients have proven necessary in other studies to demonstrate transmission of P. jirovecii (37). We believe that the reported transmission event remains a hypothesis.

Top

Philippe HauserComments to Author , Meja Rabodonirina, and Gilles Nevez
Author affiliations: Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P. Hauser); Université Claude-Bernard, Hospices Civils de Lyon, Lyon, France (M. Rabodonirina); Université de Brest, Brest, France (G. Nevez)

Top

References

  1. Rivero  L, de la Horra  C, Montes-Cano  MA, Rodríguez-Herrera  A, Respaldiza  N, Friaza  V, Pneumocystis jirovecii transmission from immunocompetent carriers to infant. Emerg Infect Dis. 2008;14:11168. DOIPubMedGoogle Scholar
  2. Beard  CB, Roux  P, Nevez  G, Hauser  PM, Kovacs  JA, Unnasch  TR, Strain typing methods and molecular epidemiology of Pneumocystis pneumonia. Emerg Infect Dis. 2004;10:172935.PubMedGoogle Scholar
  3. de Boer  MG, Bruijnesteijn van Coppenraet  LE, Gaasbeek  A, Berger  SP, Gelinck  LB, van Houwelingen  HC, An outbreak of Pneumocystis jiroveci pneumonia with 1 predominant genotype among renal transplant recipients: interhuman transmission or a common environmental source? Clin Infect Dis. 2007;44:11439. DOIPubMedGoogle Scholar
  4. Höcker  B, Wendt  C, Nahimana  A, Tönshoff  B, Hauser  PM. Molecular evidence of Pneumocystis transmission in pediatric transplant unit. Emerg Infect Dis. 2005;11:3302.PubMedGoogle Scholar
  5. Rabodonirina  M, Vanhems  P, Couray-Targe  S, Gillibert  RP, Ganne  C, Nizard  N, Molecular evidence of interhuman transmission of Pneumocystis pneumonia among renal transplant recipients hospitalized with HIV-infected patients. Emerg Infect Dis. 2004;10:176673.PubMedGoogle Scholar
  6. Schmoldt  S, Schuhegger  R, Wendler  T, Huber  I, Söllner  H, Hogardt  M, Molecular evidence of nosocomial Pneumocystis jirovecii transmission among 16 patients after kidney transplantation. J Clin Microbiol. 2008;46:96671. DOIPubMedGoogle Scholar
  7. Nevez  G, Chabé  M, Rabodonirina  M, Virmaux  M, Dei-Cas  E, Hauser  PM, Nosocomial Pneumocystis jirovecii infections. Parasite. 2008;15:35965.PubMedGoogle Scholar

Top

Cite This Article

DOI: 10.3201/eid1503.081350

Related Links

Top

In Response

We appreciate the comments from Hauser and colleagues (1) regarding our article that reported a case of Pneumocystis jirovecii transmission from colonized grandparents to their infant granddaughter (2). We agree with the authors that the 2 markers used for typing, which are described in our article, present a small number of alleles and thus provide low discrimination between isolates. However, these typing methods have been validated and have proven useful for molecular epidemiologic applications in P. jirovecii colonization studies (3,4). Unfortunately, other typing methods that can identify a high number of alleles, such as the sequence analysis of the internal transcribed spacer no. 1 and 2 gene regions, could not be used in our study because a low amplification rate has been observed for these regions when such methods are used to study colonized subjects (5). On the other hand, the multitarget single-strand conformation polymorphism method has been used only in patients with Pneumocystis pneumonia, and its usefulness for epidemiologic studies in colonized subjects has not been proven (6). For our study, we think that genotyping analysis of the mtLSU rRNA gene together with the dihydropteroate synthase (DHPS) gene provided sufficient epidemiologic information because this strategy allows identification of 24 different combinations of genotypes. However, no typing method is able to demonstrate interhuman P. jirovecii transmission conclusively because a common environmental source of infection cannot be ruled out in any case. Therefore, as we noted in our article, “We cannot exclude the possibility that the cases described were infected by the same environmental source,” and we only hypothesized that “the infant was infected by P. jirovecii through close contact with her grandparents.” However, we continue to think that the airborne transmission of P. jirovecii from the grandfather to the grandmother and the infant is the most probable explanation based on genotype data. Also, all persons in close contact with the infant were studied, and only her grandparents were colonized by P. jirovecii. Future research is needed to assess the importance of colonized subjects in the P. jirovecii transmission to susceptible hosts.

Enrique J. Calderón, CIBER en Epidemiología y Salud Pública, Servicio de Medicina Interna, Hospital Universitario Virgen del Rocío, Avda, Manuel Siurot s/n, 41013 Seville, Spain
Author affiliations: Instituto de Biomedicina de Sevilla, Virgen del Rocío University Hospital, Seville, Spain

References

  1. Hauser  P, Rabodonirina  M, Nevez  G. Pneumocystis jirovecii transmission from immunocompetent carriers to infant. Emerg Infect Dis. 2009;15:5067. DOIPubMedGoogle Scholar
  2. Rivero  L, de la Horra  C, Montes-Cano  MA, Rodríguez-Herrera  A, Respaldiza  N, Friaza  V, Pneumocystis jirovecii transmission from immunocompetent carriers to infant. Emerg Infect Dis. 2008;14:11168. DOIPubMedGoogle Scholar
  3. Montes-Cano  MA, de la Horra  C, Martín-Juan  J, Varela  JM, Torronteras  R, Respaldiza  N, Pneumocystis jirovecii genotypes in Spanish population. Clin Infect Dis. 2004;39:1238. DOIPubMedGoogle Scholar
  4. Vidal  S, de la Horra  C, Martín  J, Montes-Cano  MA, Rodríguez  E, Respaldiza  N, Pneumocystis jirovecii colonization in patients with interstitial lung disease. Clin Microbiol Infect. 2006;12:2315. DOIPubMedGoogle Scholar
  5. Esteves  F, Montes-Cano  MA, de la Horra  C, Costa  MC, Calderon  EJ, Antunes  F, Pneumocystis jirovecii multilocus genotyping profiles in patients from Portugal and Spain. Clin Microbiol Infect. 2008;14:35662. DOIPubMedGoogle Scholar
  6. Beard  CB, Roux  P, Nevez  G, Hauser  PM, Kovacs  JA, Unnasch  TR, Strain typing methods and molecular epidemiology of Pneumocystis pneumonia. Emerg Infect Dis. 2004;10:172935.PubMedGoogle Scholar

Table of Contents – Volume 15, Number 3—March 2009

Comments

Please use the form below to submit correspondence to the authors or contact them at the following address:

Philippe Hauser, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Institute of Microbiology, Rue Bugnon 48 Lausanne 1011, Switzerland

Enrique J. Calderón, CIBER en Epidemiología y Salud Pública, Servicio de Medicina Interna, Hospital Universitario Virgen del Rocío, Avda, Manuel Siurot s/n, 41013 Seville, Spain

Send To

10000 character(s) remaining.

Top

Page created: December 07, 2010
Page updated: December 07, 2010
Page reviewed: December 07, 2010
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.
file_external