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At least 19 recordsLinked to original sources

Reinfection with influenza A (H3N2) virus in young children and their families.

The frequency and consequences of reinfection with influenza A virus were studied by longitudinal observation of families for a three-year period in which two epidemics of influenza A (H3N2) occurred. Seven children followed from birth were reinfected 10-25 months after their first infection. Two children were reinfected by the same H3N2 virus while the others were reinfected with a closely related variant. At least five of these reinfections were accompanied by respiratory illness. Reinfection illness was similar to that accompanying primary infection. For children in the second and third year of life during the 1978 epidemic, the rate of infection was the same for those who had been previously infected (seven of 12) as for those who had not been previously infected (22 of 40). Reinfection was detected in 26% of older siblings and 6% of parents. The occurrence of reinfection may have important implications for elucidation of the protective immune response and for development of prophylaxis for influenzal infections.

Antibodies, Viral

[Gonococcal sensitivity to penicillin in women with gonorrhea relapse and reinfection].

Penicillin sensitivity of gonococci isolated from patients with relapses and reinfection of gonorrhea was studied. The results of the study were compared with those of the sensitivity tests in primary patients. The gonococcal strains with decreased sensitivity to penicillin were isolated from 82 per cent of the gonorrhea relapses, 47.8 per cent of the patients with reinfection and 33.2 per cent of the primary patients. The average sensitivity of the gonococcal strains isolated from the patients with relapses was 0.404 U/ml, while that in the primary patients and the patients with reinfection was 0.136 U/ml. Strains sensitive to 0.6--1.2 U/ml predominated among gonococci with decreased sensitivity in the patients with relapses, while in the primary patients and the ones with reinfection the value amounted to 0.1--0.2 U/ml. The penicillin sensitivity of gonococci may be used as a parameter in differential diagnosis of relapses and reinfection of gonorrhea.

Adolescent

The treatment of herpetic reinfection with levamisole.

The effect of levamisole on both clinical disease and virus recovery was studied in rabbits that were first infected with herpes simplex virus in one eye and then reinfected 14 days later by inoculation of the second eye. Reinfected rabbits treated with levamisole before reinfection developed significantly milder and smaller lesions than untreated controls. Virus recovery from the corneas was also less in the levamisole-treated animals than in the untreated controls.

Animals

Reinfection primary and secondary syphilis: the post treatment serologic response.

It has long been observed that patients with reinfection primary and secondary syphilis have a slower serologic response to treatment than those with an initial infection. The case records of three patients with reinfection primary and seven patients with reinfection secondary syphilis were examined and confirmed the clinical observation.

Fluorescent Antibody Technique

Turnover of tritiated-thymidine-labeled mononuclear cells in tuberculous lesions of rabbits: a comparison of primary dermal BCG lesions and those of reinfection.

Rabbits were infected or reinfected intradermally in multiple sites with BCG. One day before the BCG infection they were injected iv with a single pulse of tritiated thymidine (3HT). At various times thereafter, the BCG lesions were biopsied and evaluated for 3HT-labeled mononuclear cells (MN), which are mostly macrophages but include some lymphocytes. Periodically Old Tuberculin (OT) was infected intradermally, creating MN traps, which were biopsied and evaluated 1 day after their onset. These traps monitor the population of 3HT-labeled MN in the blood stream that readily enters sites of inflammation. During the first 5 days after the 3HT pulse, a higher percentage of labeled MN accumulated in tuberculin traps on rabbits reinfected with BCG than in traps on rabbits with primary infection. The high percentage of labeled MN in the former was probably due to the more intense inflammation cuased by preexisting tuberculin hypersensitivity. By 8 days after the 3HT pulse, a lower percentage of labeled MN had accumulated in BCG lesions of reinfection than in primary BCG lesions. Evidently the presence of delayed hypersensitivity increased the turnover of MN in tuberculous lesions. By 15 days after the 3HT pulse, the percentage of 3HT-labeled MN was much higher in BCG lesions than in 1-day traps, suggesting that such MN had accumulated in the lesions over a period of several days.

Animals

Differences in attachment antigens of gonococci in reinfection.

On the basis of bacterial typing, pyocin typing, and antibiotic sensitivity tests, two consorts appeared to have been reinfected 34 and 41 days later, respectively, with the same gonococcal strain, suggesting a failure in these patients to develop effective immunity to reinfection. However, these tests do not measure antigens which mediate attachment, a function which may correlate with virulence. When the above infecting strains were retested in an inhibition-of-attachment assay using rabbit gonococcal antisera, the antigens mediating attachment were found to be different. Homologous antisera inhibited attachment of the homologous strain at a high titer. Absorbing the antisera with the initial infecting strain did not remove any of the blocking activity of the antisera raised to the reinfecting strai, but the latter strain did share some attachment antigens in common with the initial infecting strain. Homologous antisera also bound preferentially to pili purified from the homologous strains.

Antigen-Antibody Reactions

[Serological demonstration of a Treponema pallidum reinfection].

An improved method for precise separation of 19-S-IgM from other immunoglobulines reveals the reappearance of antitreponemal 19-S-IgM-antibodies after reinfection in five patients. The IgM-FTA-ABS-test with non-separated full-serum was non-reactive in all cases due to competitive inhibition. The new assay apparently permits a clear differentiation between reinfection and non-specific increase of titers in lipoidal antigen tests. Treatment failures can be distinguished from reinfections in cases where this method can continuously be applied.

Adult

[The effect of toxoplasma antibodies after reinfection with T. gondii. II. Communication: investigations over the incidence of toxoplasma in peripheral blood after primary and secondary infection (author's transl)].

After reinfection, parasites could be detected through transfusion of tail blood to healthy mice between 24 and 100 to 352 hours. A time point beyond this was not examined. Parasitaemia could be frequently established between 68 and 76 hours post reinfection. Infection immunity in mice does not protect against reinfection by Toxoplasma. It occurs after oral infection inspite of the presence of humoral antibodies. The parasites spread by blood circulation and increase the titer by one or two titer steps in the SABIN FELDMAN test.

Animals

Immunity to chlamydial infections of the eye. IV. Immunity in owl monkeys to reinfection with trachoma.

In a study of trachoma in owl monkeys, it was found that owl monkeys are equally susceptible to low and high doses of trachoma and that resistance to reinfection persisted for six months in the majority of animals. Previous infections with a single trachoma type did not elicit greater resistance than previous infections with two types. Both serum antibodies and eye secretion titers correlated well with resistance to reinfection, but it is not as yet clear if either or both play a substantial role in immunity to trachoma.

Animals

Haemoproteus columbae: course of infection, relapse and immunity to reinfection in the pigeon.

Studies were performed on the course of infection, relapse, and immunity to reinfection in 11 young pigeons infected with the avian malaria parasite Haemoproteus columbae Kruse. The prepatent period in our experiments varied between 22 and 37 days. The intensity and length of the initial infection period showed wide variations. During this period an initial periodicity of gametocyte production of about 12 days with peaks at about 6-8 and 18-20 days after patency was observed. The various modes of infection (fly bite, intramuscular, intravenous, or intraperitoneal inoculation of sporozoites) did not influence the intensity of the initial infection. No pathogenicity due to heavy infection with the parasite was observed. There was no periodicity of relapse occurrence, nor any correlation between the frequency of relapse and the intensity of the initial infection, and the phenomenon was not influenced by seasonal changes. Pigeons (Columba livia) that had recovered from previous infections were susceptible to reinfection, whereas pigeons with chronic infection acquired immunity (premunition).

Animals

Respiratory-syncytial-virus infections, reinfections and immunity. A prospective, longitudinal study in young children.

To better understand acquired immunity to respiratory-syncytial-virus infections, we analyzed data from a 10-year study of respiratory illness in normal children who were followed longitudinally from early infancy. Immunity was measured in terms of failure to become infected or reduction in severity of clinical illness upon reinfection. Outbreaks of infections occurred seven times over the 10-year-period. During epidemics the attack rate for first infection was 98 per cent. The rate for second infections (75 per cent) was modestly reduced (P less than 0.001); that for third infections was 65 per cent. Age and history of infection both influenced illness. Immunity induced by a single infection had no demonstrable effect on illness associated with reinfection one year later; however, a considerable reduction in severity occurred with the third infection. These observations suggest that amelioration of illness--rather than prevention of infection--may be a realistic goal for immunoprophylaxis.

Antibodies, Viral

Immunity to vaginal reinfection in female guinea pigs infected sexually with Chlamydia of guinea pig inclusion conjunctivitis.

Guinea pig boars were inoculated intraurethrally with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). At the heights of their urethral infections, they were caged with sows in estrus. Whereas some of the sows had not been previously exposed to GPIC agent, others had received an intravaginal inoculation 5 to 8 weeks earlier. Those sows for which infected boars provided the first exposure were challenged by intravaginal inoculation 5 to 8 weeks later. Vaginal and conjunctival scrapings were taken regularly and stained for chlamydial inclusions. Titers of serum anti-GPIC antibodies and of vaginal secretory IgA anti-GPIC antibodies were determined by immunofluorescence. Our results show for the first time that a sexually acquired vaginal GPIC infection induces immunity to manual reinfection of the vagina. Because of the high incidence of secondary conjunctival infections among the vaginally infected sows, we could not provide a sound statistical basis for our tentative conclusion that manual infection of the vagina induces immunity to sexual reinfection. The results of our antibody titrations confirm previous work showing that vaginal GPIC infection induces formation of both serum antibody and vaginal secretory immunoglobulin A antibody.

Animals

Early malignant syphilis observed during infection and reinfection in the same patient.

Malignant syphilitic infections occurring in the same woman at an interval of 38 months is reported. The first infection was diagnosed as secondary papulopustular and ecthymatous syphilis. The reinfection was more severe, taking the form of secondary ulcerative syphilis with fever, general deterioration, and loss of weight. Numerous Treponema pallidum were present in the serum expressed from the papulopustular lesions during the first infection, but they were absent from the secretion expressed from the margins of the ulcerative symphilides during the reinfection. Many treponemes were present in the plasma cell infiltrates in histopathological sections of the biopsy specimens taken from the margin of the ulcers.

Adult

The effect of different zooxanthellae on the growth of experimentally reinfected hosts.

1. A method is given enabling the differential effects of different strains of zooxanthellae on host growth to be assessed. This technique uses the increase in the number of tentacles as the measure of growth. 2. Aposymbiotic polyps of the anemone Aiptasia pulchella reinfected with strains of Symbiodinium microadriaticum isolated from the anemone Aiptasia pulchella and the scyphozoan Cassiopea xamachana grow as well as normal Aiptasia polyps. 3. Aposymbiotic Aiptasia polyps reinfected with zooxanthellae from the gastropod Melibe pilosa and the clam Tridacna maxima grew no better than polyps lacking zooxanthellae. 4. These results lead to the conclusion that strains of zooxanthellae differ in their ability to enhance growth of Aiptasia polyps under the experimental conditions and that these differences may have important ecological consequences.

Animals

[A new method for serologic detection of Treponema pallidum reinfection].

Sources of error in the detection of specific IgM-antibodies against Treponema pallidum could be overcome by the introduction of a new method for precise separation of immunoglobulins. The 19-S-IgM-FTA-ABS-test apparently permits a correct diagnosis of syphilitic reinfection. This method is not only specific but also earlier reactive than the VDRL-test. The short-time persistence of 19 S-IgM production after treatment and its renewed appearance enables for the first time a differentiation between treatment failure and reinfection.

Adolescent

Genomic and clinical epidemiology of SARS-CoV-2 in coastal Kenya: insights into variant circulation, reinfection, and multiple lineage importations during a post-pandemic wave.

BACKGROUND: Between November 2023 and March 2024, coastal Kenya experienced another wave of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections detected through our continued genomic surveillance. Herein, we report the clinical and genomic epidemiology of SARS-CoV-2 infections from 179 individuals (a total of 185 positive samples) residing in the Kilifi Health and Demographic Surveillance System (KHDSS) area (~ 900 km2). METHODS: We analyzed genetic, clinical, and epidemiological data from SARS-CoV-2 positive cases across pediatric inpatient, health facility outpatient, and homestead community surveillance platforms. Phylogenetic analyses were performed using maximum-likelihood and Bayesian frameworks. Temporal trends were summarized, comparisons conducted using Kruskal-Wallis and Wilcoxon tests, and associations examined using univariate and multivariable logistic regression models. RESULTS: Sixteen SARS-CoV-2 lineages within 3 subvariants [XBB.2.3-like (58.4%), JN.1-like (40.5%), and XBB.1-like (1.1%)] were identified. The symptomatic infection rate was estimated at 16.0% (95% CI, 11.1-23.9%) based on community testing regardless of symptom status and did not differ across the subvariants (p = 0.13). The most common infection symptoms in community cases were cough (49.2%), fever (27.0%), sore throat (7.3%), headache (6.9%), and difficulty in breathing (5.5%). One case succumbed to the infection. Genomic analysis of the virus from serial positive samples confirmed repeat infections among 5 participants under follow-up (median interval 21 days, range 16-95 days); in 4 participants, the same virus lineage was responsible in both episodes, whereas 1 participant had a different lineage in the second compared with the first episode. Phylogenetic analysis including > 18,000 contemporaneous global sequences provided evidence for at least 38 independent virus introduction events into the study area (KHDSS) during the wave, the majority likely originating in North America and Europe. CONCLUSIONS: Our study highlights that coastal Kenya, like most other localities, continues to face new SARS-CoV-2 infection waves characterized by circulation of new variants, multiple lineage importations, and reinfections. Locally, the virus may circulate unrecognized, as most infections are asymptomatic in part due to high population immunity after several waves of infection. Our findings highlight the need for sustained SARS-CoV-2 surveillance to inform appropriate public health responses, such as scheduled vaccination for populations at risk of severe infection.

COVID-19

The effect of iron and protein deficiency on the development of acquired resistance to reinfection with Nippostrongylus brasiliensis in rats.

Iron and protein deficiency delays the immunological rejection of Nippostrongylus brasiliensis from the small intestine of rats undergoing a primary infection with the parasite. In the present study, iron and protein deficiency significantly reduced acquired resistance to reinfection with N. brasiliensis. Repletion of deficient animals with iron and protein restored their capacity to mount an effective immune response to a secondary infection with the parasite. These results suggest that chemotherapy of helminthiasis should be integrated with nutritional supplementation.

Animals

Failure of nude (athymic) rats to become resistant to reinfection with the intestinal coccidian parasite Eimeria nieschulzi or the nematode Nippostrongylus brasiliensis.

The course of each of three successive infections with Eimeria nieschulzi in nude (athymic) rats was the same as the primary infection in nu/+ animals, with the production of more oocysts. This indicates that resistance to reinfection with this parasite is mediated by T lymphocytes but that these cells do not control the duration of the life cycle, since oocyst production was not prolonged in the nu/nu rats. After the three infections with E. nieschulzi, the rats were exposed twice to the intestinal nematode Nippostrongylus brasiliensis, and the nu/nu were completely susceptible even to the second infection. Egg production by both infections in the nu/nu animals was similar and continued at a high plateau level for 28 days before falling to a low level. It appears that the strain of N. brasiliensis used in this study is unable to sustain high egg production for more than 4 weeks in T cell deficient rats.

Animals