Charles R. Manclark

Pertussis in a previously immunized child with human immunodeficiency virus infection

The management of children with human immunodeficiency virus infection in whom changes in pulmonary status develop can be complex. They are susceptible to a broad range of infections, and the clinician must be aware of the multiple etiologic possibilities and appropriate diagnostic tests. This report presents a potential pathogen that should be added to the list of organisms that can cause gram-negative pneumonia in children with HIV infection and highlights a diagnostic pitfall.

Malaria chemoprophylaxis and the serologic response to measles and diphtheria-tetanus-whole-cell pertussis vaccines

BackgroundAcute malaria has been associated with a decreased antibody response to tetanus and diphtheria toxoids, meningococcal, salmonella, and Hib vaccines. Interest in giving malaria drug therapy and prevention at the time of childhood immunizations has increased greatly following recent trials of intermittent preventive therapy during infancy (IPTi), stimulating this re-analysis of unpublished data. The effect of malaria chemoprophylaxis on vaccine response was studied following administration of measles vaccines and diphtheria-tetanus-whole cell pertussis (DTP) vaccines.MethodsIn 1975, six villages divided into two groups of children ≤74 months of age from Burkina Faso, were assigned to receive amodiaquine hydrochloride chemoprophylaxis (CH+) every two weeks for seven months or no chemoprophylaxis (CH-). After five months, children in each group received either one dose of measles or two doses of DTP vaccines.ResultsFor recipients of the measles vaccine, the seroconversion rates in CH+ and CH- children, respectively, were 93% and 96% (P > 0.05). The seroresponse rates in CH+ and CH- children respectively, were 73% and 86% for diphtheria (P > 0.05) and 77% and 91% for tetanus toxoid (P > 0.05). In a subset analysis, in which only children who strictly adhered to chemoprophylaxis criteria were included, there were, likewise, no significant differences in seroconversion or seroresponse for measles, diphtheria, or tetanus vaccines (P > 0.05). While analysis for pertussis showed a 43% (CH+) and 67% (CH-) response (P < 0.05), analyses using logistic regression to control for sex, age, chemoprophylaxis, weight-for-height Z-score, and pre-vaccination geometric mean titer (GMT), demonstrated that chemoprophylaxis was not associated with a significantly different conversion rate following DTP and measles vaccines. Seven months of chemoprophylaxis decreased significantly the malaria IFA and ELISA GMTs in the CH+ group.ConclusionMalaria chemoprophylaxis prior to vaccination in malaria endemic settings did not improve or impair immunogenicity of DTP and measles vaccines. This is the first human study to look at the association between malaria chemoprophylaxis and the serologic response to whole-cell pertussis vaccine.

Recent advances in the development of pertussis vaccines.

Publisher Summary This chapter describes Bordetella pertussis and discusses recent advances in the development of pertussis vaccines. Bordetella pertussis is the pathogen that causes the human respiratory disease known as whooping cough, or pertussis. It is a fastidious Gram-negative bacillus that has a particular tropism for the ciliated epithelium of the respiratory tract. Pertussis begins as a mild upper respiratory infection that generally lasts 7–10 days, with nonspecific symptoms, usually in the absence of fever. During this initial and most infectious stage of disease, known as the catarrhal stage, the organism can be cultured from the nasopharynx. The disease usually progresses to the paroxysmal stage, typified by episodes of paroxysmal coughing, which, in young children, may be accompanied by an inspiratory whoop although this is often absent in infants younger than six months of age. Paroxysmal episodes may be followed by vomiting. The chapter also discusses new pertussis vaccines by examining the properties of the current whole cell vaccine. There is little doubt that whole cell pertussis vaccine (WCPV) has controlled pertussis in the communities where it has been adequately prepared and used under recommended protocols.