Nasopharyngeal carriage of Streptococcus pneumoniae in Navajo and White Mountain Apache children before the introduction of pneumococcal conjugate vaccine.

Background: Infants and children are frequently colonized with pneumococcus. Recent nasopharyngeal acquisition of pneumococcus is thought to precede disease episodes. The increased risk of pneumococcal disease among Navajo and White Mountain Apache populations has been documented.

Indirect effect of 7-valent pneumococcal conjugate vaccine on pneumococcal colonization among unvaccinated household members.

Background: Since the introduction of 7-valent pneumococcal conjugate vaccine (PCV7) in the United States, rates of invasive pneumococcal disease have decreased in both vaccinated and unvaccinated age groups. Reduction of invasive pneumococcal disease in unvaccinated groups has been attributed to reduced transmission of vaccine-type pneumococci in the community. Understanding the impact of PCV7 on carriage among vaccinated and unvaccinated community members is critical to interpreting, predicting, and understanding the impact of PCV7 on disease.

Effect of pneumococcal conjugate vaccine on nasopharyngeal colonization among immunized and unimmunized children in a community-randomized trial.

Background: Pneumococcal conjugate vaccines (PCVs) prevent vaccine serotype (VT) invasive disease; nonvaccine serotype (NVT) disease increases modestly. The impact of PCV on nasopharyngeal (NP) colonization is essential to understanding disease effects.

Methods: We conducted a community-randomized controlled trial with catch-up vaccination through age 2 years investigating the effect of 7-valent PCV (PnCRM7) on NP colonization among American Indian infants and their unvaccinated contacts.

Anticapsular serum antibody concentration and protection against pneumococcal colonization among children vaccinated with 7-valent pneumococcal conjugate vaccine.

Background: Pneumococcal conjugate vaccines prevent invasive and noninvasive disease due to infection with vaccine serotypes. Pneumococcal conjugate vaccines also prevent nasopharyngeal acquisition of vaccine serotypes, although the mechanism is incompletely understood.

Methods: An efficacy trial of a 7-valent pneumococcal conjugate vaccine was conducted on the Navajo and White Mountain Apache reservations, located in the Southwestern United States; group C meningococcal conjugate vaccine was the control vaccine.

Effect of community-wide conjugate pneumococcal vaccine use in infancy on nasopharyngeal carriage through 3 years of age: a cross-sectional study in a high-risk population.

Background: A 7-valent pneumococcal conjugate vaccine (PnCRM7) has been shown to be highly effective in preventing invasive pneumococcal disease. Pneumococcal conjugate vaccines also protect against nasopharyngeal carriage of vaccine serotypes, but the duration of protection against nasopharyngeal carriage is not known.

Methods: A group-randomized efficacy trial of PnCRM7 (vaccine serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F) was conducted on the Navajo and White Mountain Apache reservations from April 1997 to October 2000.

Streptococcus pneumoniae and Haemophilus influenzae type B Carriage, Central Asia.

A study of children was conducted in 3 Central Asian Republics. Approximately half of the Streptococcus pneumoniae isolates were serotypes included in available vaccine formulations. Approximately 6% of children carried Haemophilus influenzae type b (Hib).

Nasopharyngeal versus oropharyngeal sampling for detection of pneumococcal carriage in adults.

Several studies have shown that nasopharyngeal sampling is more sensitive than oropharyngeal sampling for the detection of pneumococcal carriage in children. The data for adults are limited and conflicting. This study was part of a larger study of pneumococcal carriage on the Navajo and White Mountain Apache Reservation following a clinical trial of a seven-valent pneumococcal conjugate vaccine.

Immunoblot method to detect Streptococcus pneumoniae and identify multiple serotypes from nasopharyngeal secretions.

Conventional culture techniques are limited in the ability to detect multiple Streptococcus pneumoniae serotypes in nasopharyngeal (NP) secretions. We developed an immunoblot (IB) method with monoclonal antibodies (MAbs) to detect S. pneumoniae and to identify serotypes.

Specific, sensitive, and quantitative enzyme-linked immunosorbent assay for human immunoglobulin G antibodies to anthrax toxin protective antigen.

The bioterrorism-associated human anthrax epidemic in the fall of 2001 highlighted the need for a sensitive, reproducible, and specific laboratory test for the confirmatory diagnosis of human anthrax. The Centers for Disease Control and Prevention developed, optimized, and rapidly qualified an enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) antibodies to Bacillus anthracis protective antigen (PA) in human serum. The qualified ELISA had a minimum detection limit of 0.

Evaluation of a medium (STGG) for transport and optimal recovery of Streptococcus pneumoniae from nasopharyngeal secretions collected during field studies.

Field studies of Streptococcus pneumoniae (pneumococci) nasopharyngeal (NP) colonization are hampered by the need to directly plate specimens in order to ensure isolate viability. A medium containing skim milk, tryptone, glucose, and glycerin (STGG) has been used to transport and store NP material, but its ability to preserve pneumococci has not been evaluated. Our objective was to qualitatively and semiquantitatively evaluate the ability of STGG to preserve pneumococci in NP secretions.

Detection of enzootic babesiosis in baboons (Papio cynocephalus) and phylogenetic evidence supporting synonymy of the genera Entopolypoides and Babesia.

Blood smear evaluation of two baboons (Papio cynocephalus) experiencing acute hemolytic crises following experimental stem cell transplantation revealed numerous intraerythrocytic organisms typical of the genus Babesia. Both animals had received whole-blood transfusions from two baboon donors, one of which was subsequently found to display rare trophozoites of Entopolypoides macaci. An investigation was then undertaken to determine the prevalence of hematozoa in baboons held in our primate colony and to determine the relationship, if any, between the involved species.

Genetic evidence for host specificity in the adhesin-encoding genes hxaA of Helicobacter acinonyx, hnaA of H. nemestrinae and hpaA of H. pylori.

Gastric and non-gastric species of Helicobacter were examined for the presence of the adhesin-encoding gene, hpaA, from the human-associated gastric Helicobacter H. pylori (Hp), and for adhesin subunit protein HpaA. Amplification of a 375-bp internal DNA fragment of hpaA by PCR demonstrated the presence of the gene in Hp and in two closely related gastric Helicobacters, H.

The phylogenetic position of Helicobacter nemestrinae.

Comparison of the Helicobacter nemestrinae 16S ribosomal DNA with published homologous sequences from members of the genera Helicobacter, Wolinella, and Campylobacter reveals a close relationship between H. nemestrinae, H. pylori, and H.

Helicobacter nemestrinae sp. nov., a spiral bacterium found in the stomach of a pigtailed macaque (Macaca nemestrina).

A new microaerophilic, spirally curved, rod-shaped bacterium was isolated from the gastric mucosa of a pigtailed macaque (Macaca nemestrina). The gram-negative cells of this bacterium are oxidase, catalase, and urease positive and strongly resemble Helicobacter pylori (Campylobacter pylori) cells. Like H.

Experimental infection of pig-tailed macaques (Macaca nemestrina) with Campylobacter cinaedi and Campylobacter fennelliae.

Campylobacter cinaedi and C. fennelliae have been associated with proctocolitis, bacteremia, and asymptomatic rectal infection, primarily in homosexual men. To more directly assess the pathogenic role of these organisms, we studied their disease-producing potential in 12- to 25-day-old pig-tailed macaques (Macaca nemestrina).

Experimental cryptosporidiosis in a primate model.

Cryptosporidium causes a disease in infant macaques that is clinically, histologically, and microbiologically indistinguishable from that seen in young children. A reproducible experimental model of cryptosporidiosis has been developed in pigtailed macaques (Macaca nemestrina) and used to studied the infectious dose of oocysts and the effect of inoculum size on severity of disease. Inoculation with either 2 x 10(5) or 10 oocysts via nasogastric tube resulted in clinical enteritis and the fecal passage of large numbers of cryptosporidial oocysts in all four primates studied.

Clinical and parasitologic aspects of cryptosporidiosis in nonhuman primates.

Eighty-one cases of acute cryptosporidiosis were diagnosed among 157 (52%) infant primates, predominantly Macaca nemestrina, housed in the nursery unit of the Washington Regional Primate Research Center. The mean age at onset of oocyst passage was 38 +/- 25 days. The outbreak was confined to the nursery and no cases were detected among juvenile or adult primates housed in other rooms within the colony.

Cellular fatty acid composition of Campylobacter pylori from primates and ferrets compared with those of other campylobacters.

The cellular fatty acid profiles of newly described campylobacters were determined on a polar, capillary column. Six isolates of the gastric spiral organism, Campylobacter pylori subsp. mustelae, from ferrets from Australia, England, and the United States were all found to have a similar fatty acid profile which was different from that of C.

Campylobacter pylori isolated from the stomach of the monkey, Macaca nemestrina.

Campylobacter pylori was isolated from the gastric mucosa in 6 of 24 pigtailed macaques (Macaca nemestrina) examined by gastric biopsy and culture; 3 isolates were recovered during gastroendoscopy, and 3 were recovered at necropsy. The isolates were morphologically and biochemically similar to the human type strain NCTC 11638, differing only in colony diameter, pigmentation, and rate of growth. Identity of the isolates was confirmed by whole-genomic DNA-DNA hybridization with the type strain.

Epidemiology and etiology of diarrhea in colony-born Macaca nemestrina.

The epidemiology of diarrhea in colony-born M. nemestrina was studied in 205 neonates and infants in an Infant Primate Research Laboratory (IPRL), and in 248 neonates, juveniles and adolescents up to 4 years of age at a separate breeding and holding facility (Primate Field Station, PFS). Computerized medical records of individual animals over a 5-year period were analyzed to determine the incidence of diarrhea; age, duration and number of episodes; mortality and etiology.

Rapid dimethyl sulfoxide-modified acid-fast stain of Cryptosporidium oocysts in stool specimens.

A rapid dimethyl sulfoxide modification of an acid-fast technique was applied to direct fecal smears to monitor cryptosporidiosis in nonhuman primates. Brilliantly stained pink oocysts against a pale green background demonstrated well-preserved internal morphology and facilitated rapid, simple, noninvasive diagnosis without fluorescent or phase-contrast microscopy.

Identification of Campylobacter jejuni in Macaca fascicularis imported from Indonesia.

Campylobacter jejuni was selectively cultured in 33 (66%) of 50 Macaca fascicularis that had been imported from Indonesia. As there was no published information on the incidence of Campylobacter infection in nonhuman primates from Indonesia, a survey was conducted to determine the presence and incidence of Campylobacter jejuni in 50 macaques before they were exported from Indonesia. The organism was positively identified in 18 (36%) of the specimens examined.