Gaelle Noel1, Masoumeh Nakhost Lotfi2, Nicole Guiso3, Fereshteh Shahcheraghi2, Fabien Taieb3,4, Sajedeh Mirshahvalad2, Sedaghatpour Mahdi2, David Tavel5, Seyed M Zahraei6, Roxana Mansour Ghanaie7, Tahereh Heidary8, Aliahmad Goudarzi9, Azardokht Kazemi10, Abdollah Karimi7, Alireza Nateghian8, Mohand Ait-Ahmed11. 1. Center for Translational Science, Institut Pasteur, Paris, France. gaelle.noel@pasteur.fr. 2. Department of Bacteriology, Pertussis Reference Laboratory, Pasteur Institute of Iran, Tehran, Islamic Republic of Iran. 3. Center for Translational Science, Institut Pasteur, Paris, France. 4. Department of International Affairs, Institut Pasteur, Paris, France. 5. Emerging Diseases Epidemiology unit, Institut Pasteur, Paris, France. 6. Center for Communicable Diseases Control, Ministry of Health and Medical Education, Tehran, Islamic Republic of Iran. 7. Pediatric Infections Research Center, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Research Institute for Children's Health, Tehran, Islamic Republic of Iran. 8. Department of Pediatrics, Ali Asghar children hospital, Iran University of Medical Sciences, Tehran, Islamic Republic of Iran. 9. Pediatric cardiology department, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran. 10. Emergency Department, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran. 11. Centre for Translational Science, Clinical Coordination, Institut Pasteur, Paris, France.
Abstract
BACKGROUND: Pertussis remain a global health concern, especially in infants too young to initiate their vaccination. Effective vaccination and high coverage limit the circulation of the pathogen, yet duration of protection is limited and boosters are recommended during a lifetime. In Iran, boosters are given at 18 months and 6 years old using whole pertussis vaccines for which efficacy is not known, and pertussis surveillance is scant with only sporadic biological diagnosis. Burden of pertussis is not well understood and local data are needed. METHODS: Hospital-based prospective study implementing molecular laboratory testing in infants aged ≤6 months and presenting ≥5 days of cough associated to one pertussis-like symptom in Tehran. Household and non-household contact cases of positive infants were evaluated by comprehensive pertussis diagnosis (molecular testing and serology) regardless of clinical signs. Clinical evaluation and source of infection were described. RESULTS: A total of 247 infants and 130 contact cases were enrolled. Pertussis diagnosis result was obtained for 199 infants and 104 contact cases. Infant population was mostly < 3 months old (79.9%; 157/199) and unvaccinated (62.3%; 124/199), 20.1% (40/199) of them were confirmed having B. pertussis infection. Greater cough duration and lymphocyte counts were the only symptoms associated to positivity. Half of the contact cases (51.0%; 53/104) had a B. pertussis infection, median age was 31 years old. A proportion of 28.3% (15/53) positive contacts did not report any symptom. However, 67.9% (36/53) and 3.8% (2/53) of them reported cough at inclusion or during the study, including 20.8% (11/53) who started coughing ≥7 days before infant cough onset. Overall, only five samples were successfully cultured. CONCLUSION: These data evidenced the significant prevalence of pertussis infection among paucy or poorly symptomatic contacts of infants with pertussis infection. Widespread usage of molecular testing should be implemented to identify B. pertussis infections.
BACKGROUND: Pertussis remain a global health concern, especially in infants too young to initiate their vaccination. Effective vaccination and high coverage limit the circulation of the pathogen, yet duration of protection is limited and boosters are recommended during a lifetime. In Iran, boosters are given at 18 months and 6 years old using whole pertussis vaccines for which efficacy is not known, and pertussis surveillance is scant with only sporadic biological diagnosis. Burden of pertussis is not well understood and local data are needed. METHODS: Hospital-based prospective study implementing molecular laboratory testing in infants aged ≤6 months and presenting ≥5 days of cough associated to one pertussis-like symptom in Tehran. Household and non-household contact cases of positive infants were evaluated by comprehensive pertussis diagnosis (molecular testing and serology) regardless of clinical signs. Clinical evaluation and source of infection were described. RESULTS: A total of 247 infants and 130 contact cases were enrolled. Pertussis diagnosis result was obtained for 199 infants and 104 contact cases. Infant population was mostly < 3 months old (79.9%; 157/199) and unvaccinated (62.3%; 124/199), 20.1% (40/199) of them were confirmed having B. pertussis infection. Greater cough duration and lymphocyte counts were the only symptoms associated to positivity. Half of the contact cases (51.0%; 53/104) had a B. pertussis infection, median age was 31 years old. A proportion of 28.3% (15/53) positive contacts did not report any symptom. However, 67.9% (36/53) and 3.8% (2/53) of them reported cough at inclusion or during the study, including 20.8% (11/53) who started coughing ≥7 days before infant cough onset. Overall, only five samples were successfully cultured. CONCLUSION: These data evidenced the significant prevalence of pertussis infection among paucy or poorly symptomatic contacts of infants with pertussis infection. Widespread usage of molecular testing should be implemented to identify B. pertussis infections.
Authors: Karene Hoi Ting Yeung; Philippe Duclos; E Anthony S Nelson; Raymond Christiaan W Hutubessy Journal: Lancet Infect Dis Date: 2017-06-13 Impact factor: 25.071