Usefulness and limitations of three serologic methods for diagnosing or excluding chlamydiosis in birds.

Diagnostic serology by use of elementary body agglutination is the most useful serologic method for diagnosis of chlamydiosis in birds, because it detects only IgM activity. A titer of 10 in budgerigars, cockatiels, and lovebirds and of > or = 20 in other types of birds is interpreted as being indicative of current infection. Latex agglutination, with detects IgM and IgG activity, may be useful in detecting large changes in titer. Direct complement fixation, detecting only IgG activity, is usable to detect past infection whenever elementary body agglutination and latex agglutination titers are < 10. Limitations of serologic results necessitating additional confirmatory testing are lack of titers in the acute phase of disease and diagnostic titers in clinically normal birds with low-grade chronic infections and in birds with prolonged maintenance of titers. Additional suggested examinations are chlamydial culture by use of choanal/oropharyngeal swab samples, WBC count, determination of hepatic-associated enzyme activity, chlamydial ELISA by use of the aforementioned swab samples, and additional serologic testing.

[Industrial pollution due to organic solvents as a cause of teratogenesis]. / Contaminación industrial con solventes orgánicos como causa de teratogénesis.

OBJECTIVE: To inform of a new teratogenic syndrome in human beings and its confirmation in rats. MATERIAL AND METHODS: The study comprised three phases: a field study; a case-control study; and a genetic epidemiology study, aiming at identifying the causes of the occurrence of congenital malformations and psychomotor retardation in the city of Matamoros, Tamaulipas. The second-phase clinical multidisciplinary study was carried out at a general hospital, to conduct a comprehensive evaluation of patients identified during the first phase and offer them the necessary treatment. The third-phase experimental study was done in rats in order to confirm the teratogenic effect of the agents detected in the first phase. RESULTS: A total of 44 patients had a peculiar phenotype and mental retardation of varying degrees, all children of ex-workers of the same factory who were in direct contact, without protection, with organic solvents (methyl cellosolve and ethylene glycol). In the clinical study a syndrome was delineated, previously unreported, consisting of a peculiar facies, mental retardation, and musculo-skeletal and sensorial abnormalities. In the experimental study it was demonstrated that both methyl cellosolve and ethylene glycol cause cranio-facial, musculo-skeletal and central nervous system abnormalities, which confirmed the teratogenic effect of these solvents. CONCLUSIONS: The results of this study establish the existence of a new teratogenic syndrome in humans, produced by methyl cellosolve and ethylene glycol, whose teratogenic capacity had not been reported previously.

Diagnostic serologic testing of cage and aviary birds for chlamydiosis and suggested confirmatory testing.

A 2 x 2 contingency table was constructed to demonstrate the relationships between detectable chlamydial antibody activity and clinical health status of tested birds. The table revealed that 65.5% of clinically ill birds were antibody positive by elementary body agglutination (EBA) (> or = 10 titers) and 59.0% were antibody positive by latex agglutination (LA). Thus, EBA was slightly more sensitive than LA in detecting antibody activity. Of the clinically normal birds, 96.7% were antibody negative (< 10 titers) by EBA and 98.3% were antibody negative by LA. Individual serum or plasma samples from a group of mixed types of psittacine birds and cockatiels were tested as a separate group, and relationships between EBA-detectable antibody activity and health status were obtained from a 2 x 2 contingency table. Sixty-six percent of birds clinically ill with signs of chlamydiosis in the mixed-type group were antibody positive, whereas only 32.3% of clinically ill cockatiels were antibody positive. Statistical analysis of the contingency table using a chi-square test demonstrated that the EBA test differentiates between individual birds on the basis of health status (P < 0.001). When testing paired serum or plasma samples by EBA, LA, and direct complement fixation (DCF), the highest percentage of significant (> or =4-fold change) titer decreases was detected by LA, and the highest percentage of significant titer increases was detected by DCF. Examples of EBA, LA, and DCF titers in paired and multiple serum or plasma samples are presented to show the variety of responses that can occur. Results reflected variations seen in individual testing of birds with titer variability seen in the first sample tested. Additional types of testing believed necessary for confirming or ruling out an infectious process in birds are outlined. The current interpretations of serologic results are given.

Elementary body agglutination for rapidly demonstrating chlamydial agglutinins in avian serum with emphasis on testing cockatiels.

The development and use of a stained chlamydial elementary body agglutination (EBA) antigen for detecting antibody activity in avian sera is described. Examples of serologic results on serum samples from various types of birds indicate the usefulness of EBA, latex agglutination (LA), and direct complement fixation (DCF) in diagnosing avian chlamydiosis. Results of tests on 10 cockatiels examined in clinics indicate that a combination of serology, culture, and/or antigen-detection enzyme-linked immunosorbent assay may be helpful when testing this type of bird. Agreement between EBA, LA, and DCF was 81.8% when testing 407 serum samples from cockatiels of unknown health status. The relationship between positive (> or = 10 titer) antibody activity and known health status of 77 cockatiels revealed that agreement between the two criteria was only 59.7%. Of 13 Chlamydia-inoculated cockatiels, seven birds seroconverted from negative to positive by EBA; five seroconverted by DCF. Only the five birds that seroconverted by both EBA and DCF were culture-positive for chlamydiae. None of 15 sham-inoculated control cockatiels developed detectable antibody activity, and none of 10 cultured were positive. In tests with column-separated IgM and IgG, EBA detected only IgM activity, LA detected IgM and IgG activity, and DCF detected only IgG activity.

Chlamydia latex agglutination antigen and protocol improvement and psittacine bird anti-chlamydial immunoglobulin reactivity.

Latex agglutination detection of chlamydial antibody activity in psittacine bird sera was significantly more sensitive when an improved protocol was followed than was a test using the previously used protocol. Titers of antibody-positive sera were fourfold to 32-fold higher by the improved protocol than titers by the previously used protocol, whereas antibody-negative sera were negative by both protocols. Column chromatography was used to separate immunoglobulins in psittacine bird serum. Immunoglobulin M was reactive in latex agglutination (LA) but non-reactive in direct complement fixation (DCF). Immunoglobulin G was reactive in LA and DCF. The fifth supernatant fluid of serum multiply absorbed with latex beads was non-reactive in LA and DCF. The immunoglobulins reactive in LA had high avidity and affinity for latex beads. Prolonged storage at 4 C to 6 C preserved LA reactivity of absorbed immunoglobulins better than storage at 21 C to 23 C.

Survey of clinical psittacine bird sera for Salmonella typhimurium agglutinins.

Of 2407 serum samples from various kinds of psittacine birds submitted for Chlamydia serology, 2343 (97.4%) were negative, 25 (1.0%) were equivocal, and 39 (1.6%) were positive for Salmonella typhimurium agglutinins. In additional serum samples from two groups of African gray parrots, the prevalence of agglutinins was 0.0% (0/38) in the Timneh variety and 24.0% (6/25) in the Congo variety. In sera from one macaw, one cockatoo, and one Amazon parrot, which were negative for chlamydial antibody activity, there were strongly reactive agglutinins for S. typhimurium. Two Amazon parrots had antibody activity against Salmonella and Chlamydia antigens.