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Hepatitis B (HVB) is a worldwide spread health problem. It has been assessed that there are more than 300 millions of carriers. HVB has a special concern for health care workers (HCW's) due to the high risk among them of getting the infection in clinic-setting areas. According to some estimation, the risk for hepatitis B among HCW's is 2 to 10 times higher than the risk for general population. The risk is related to the degree of direct contact with blood and body fluids, as well as, with the frequency of traumatic exposure in the work place. The control of this infection is based on the observance of universal precautions and the vaccination, since there is not treatment against this disease. The results of an efficacy-evaluation of DNA recombinant vaccine against hepatitis B are reported; 174 HCW's were studied; three dosages of vaccine were administered (0.1st and 6th month) by I.M. via. In addition, three serum samples were collected at 0, 1st and 9th month after vaccine administration. We did not find carriers of surface antigen of hepatitis B. With regards to seroconverted individuals we observed the following results: there were a satisfactory response to the vaccine in 163 individuals (93.7%); however, 8 (4.6%) persons did not reach titles of protective antibodies and 3 (1.7%) did not show seroconversion at all. Therefore, 11 persons (6.3% of the total) did not result immunized. The secondary reactions to the vaccines were low in frequency and mainly of local presentation. Among the study population we did not find chronic carries of hepatitis B.(ABSTRACT TRUNCATED AT 250 WORDS)

The susceptibility of a strain of Giardia lamblia to benzimidazole carbamates, 5-nitroimidazoles, nitrofurans and other drugs was studied in vitro. Albendazole was the most active compound, with a 50% inhibitory concentration (IC50) of 0.01 mg/L and a minimal lethal concentration (MLC) of less than 0.04 mg/L; the IC50 of mebendazole was 0.06 mg/L and the MLC less than 0.5 mg/L. Among the 5-nitroimidazoles tested, ornidazole was the most effective (IC50 0.12 mg/L); tinidazole, metronidazole, secnidazole and hemezole were less active. Nifuroxazide, etofamide and nalidixic acid exhibited modest anti-giardial activity; quinfamide did not inhibit the growth of the parasite at a concentration of 200 mg/L. Albendazole and mebendazole are promising candidates for clinical use and should be further evaluated.

The effect of toxins A and B from Clostridium difficile on human colon carcinoma cells (HT-29, epithelial), rhesus monkey kidney cells (MA-104, epithelial) and green monkey kidney cells (VERO, fibroblast) was studied. Both toxins caused rounding of HT-29 cells and rounding with projections remaining attached to the substrate in MA-104 and VERO cells; however, the sensitivity to each toxin varies considerably. Toxin A was detected in ng by VERO, pg by HT-29 and fractions of pg by MA-104 cells; for toxin B, pg were detected by VERO, ng by MA-104 and micrograms by HT-29 cells. HT-29 cells were grown with galactose to allow their differentiation to enterocytes, and their sensitivity to the toxins during the process was studied. At early stages, the sensitivity to both toxins was similar, and as the differentiation proceeded, the response to both toxins decreased continuously, and after 16 days no evident morphological effect was observed, even with micrograms amounts of either toxin. In contrast to all cell lines reported to date, HT-29 and MA-104 epithelial cells are exquisitely sensitive to toxin A and less responsive to toxin B. The rounding of HT-29 by these toxins depends on the degree of differentiation of the cell.

To determine if rotavirus interferes with the multiplication of poliovirus, and hence the efficiency of the polio vaccine, the effect of timing and concentration of Simian rotavirus (SSA-11) on polio-1 infection in MA-104 cells was studied in vitro by evaluating the cytopathic effect, the reduction of the infectivity titers and the visualization of viral particles by electron microscopy. We found that poliovirus 1 was able to replicate when the challenge dose was administered within the first 8 h following SA-11 infection and with titers ten times lower than those of rotavirus. Hence, non-interference effect was observed in this in vitro model.

A rapid colorimetric assay for viability of E. histolytica trophozoites using the tetrazolium salt MTT and phenazine methosulfate (PMS) was developed. The MTT is normally reduced by dehydrogenases of viable cells and transformed to formazan, a colored compound; the reaction is catalyzed by PMS. Trophozoites of E. histolytica were incubated in the presence of MTT and PMS during 15, 30, 45, 60 and 75 min, at 37 degrees C. Trophozoites killed by heat or cold were used as controls. The formazan produced into the cells was extracted with isopropanol-HCl and the optical density (OD) was measured at 570 nm. There was a linear relation between the number of viable trophozoites and the OD570 (r2 = 0.98). The trophozoites killed by cold or heat did not reduce MTT. The optimal time of incubation with MTT/PMS was 45 min. The MTT/PMS assay for determining viability of E. histolytica trophozoites is reproducible, rapid and easy to perform and it could be useful to study cytotoxicity and susceptibility to drugs.

As part of the evaluation of an educational intervention carried out at primary health care units in Mexico City a home visit was included for patients treated for acute infectious diarrhea. In such visit, effected for 401 patients before the educational intervention and for 406 after the same, it was possible to evaluate compliance with the treatment measured through the amount of prescribed drugs distributed by the institution but not consumed by patients. A significant improvement was observed in compliance with the treatment even though this was not the explicit objective of the intervention. Compliance is related to variables of different dimensions--characteristics of the physician, characteristics of the patient, physician-patient rapport, health condition and health concept--and the educational intervention tends to homogenize the patient's behavior as a result of more emphatic improvement in those subgroups with worst compliance levels.

41 volunteer blood donors and his relatives were studied in order to know about the prevalence of hepatitis B and D virus infections in selected groups. Frequency of HBsAg+ carriers was 0.34 per cent in the Centro Nacional de la Transfusión Sanguínea and 0.15 per cent in the Banco Central de Sangre, IMSS. Most of the HBsAg+ blood donors were 21 to 40 years old (87.8%); 21.9 per cent had IgM antibodies against HBc and just 2.4 per cent were HBeAg positive. Forty one (26.9%) of 152 relatives had one or more of the HBV markers, 3.9 per cent were HBsAg carriers and 1.3 per cent were HBeAg positive. In the infected relatives group 36.6 per cent were ancestory or brothers and just 14.6 per cent of wives were infected. None of the HBsAg+ blood donors or his relatives had antibodies against delta agent. These results support the fact that the frequency of asymptomatic carriers of HBsAg in the volunteer blood donors group is similar to he frequency in the general population and identifies the group of relatives as those with the highest risk to acquire HBV infection.

With the purpose of evaluating the usefulness of clinical data and a coagglutination test for the diagnosis of streptococcal pharyngeal tonsillitis, a study was carried out comparing both methods with the standard pharynx culture (gold standard). One hundred and forty-one patients clinically diagnosed with pharyngeal tonsillitis were analyzed. 80 other patients diagnosed with rhino-pharyngitis were used as control groups as well as a group of 66 healthy patients. It was found that the presence of pus in the tonsils and the absence of rhinorrhea and/or a productive cough were isolated clinical variables which showed a significant difference when comparing those cases with a positive or a negative culture (P less than 0.01). These clinical data had a sensitivity and adequate negative predictive values (68 to 83% and 90 to 92%, respectively); specificity was 44 to 74% and the positive predictive value from 24 to 36%. The gathering of combined clinical indexes with different symptoms and signs, were not greater than isolated data. The coagglutination test in those cases of pharyngeal tonsillitis showed greater better specificity (98%) and positive predictive value (93%), but saw no improvement in sensitivity (72%) nor in the negative predictive value (91%), which is why when faced with a negative coagglutination test, it is still necessary to perform a throat culture due to the risk which the patient may be exposed to when no treatment is given. The analysis of the advantages and disadvantages in the routine use of coagglutination and cultures in their particular cases, allows us to conclude that in daily clinical practice the use of clinical criteria is of greater usefulness.(ABSTRACT TRUNCATED AT 250 WORDS)

The mechanisms by which Clostridium difficile causes diarrhoea are unknown. The expression of putative virulence factors by 44 Clostridium difficile strains isolated from patients with and without diarrhoea was studied. Toxins A and B were tested in CHO and MRC-5 cells, respectively; adherence was measured in two substrates: HEp-2 cells and polystyrene plates. The in vitro expression of toxins A and B by strains isolated from patients with diarrhoea was not significantly different from that by strains isolated from patients without diarrhoea. The ability of adherence to both HEp-2 cells and polystyrene by strains isolated from patients with diarrhoea was not significantly different when compared with strains isolated from patients without diarrhoea; however, strains isolated from adults with diarrhoea seem to adhere to a greater extent to both substrates than strains isolated from adults without diarrhoea. Twenty three strains which did not produce toxins A and B were tested for enterotoxicity in rat small intestine. Eight such strains induced fluid accumulation and seven of them were isolated from children. Adherence to cells and to polystyrene might be an important virulence factor in strains causing diarrhoea in adults; whereas the production of toxins other than A and B might be an important pathogenic mechanism in strains causing diarrhoea in children.

The frequency of colonization by Clostridium difficile in 273 hospitalized children under 15 years of age was studied. Feces were collected from patients attending the infectious disease service at the Pediatric Hospital IMSS, during a period of 11 months. No colonization was detected in 16 neonates; whereas 10 of 103 children (9.7%) under one year of age, 7 of 84 children (8.3%) from one to five years and 3 of 70 children (4.2%) from five to 15 years of age were colonized. The use of antibiotics and the nutritional state were studied as possible risk factors for colonization. The frequency of colonization was not influenced by the nutritional state, whereas the treatment with antibiotics decreased significantly the colonization in children under one year of age but not in those children over one year of age. In children under one year of age, the cytotoxin was more frequent in cases of diarrhea, and in those over one year no association was found. The 50 strains isolated from these children were classified according to: toxigenicity, sensitivity to antibiotics, phages and bacteriocins. Strains acquired before hospitalization were more toxigenic than those acquired intrahospital. Twelve resistotypes were detected; one of them (V) was more frequent in intrahospital strains. Ten phagobacteriocin types were found, and two of then (D and I) were present only in intrahospital strains. Using this classification scheme, it was found that eight patients were colonized with two different strains at the same time.

A rubella seroepidemiologic survey was carried out in a rural population to better understand the epidemiology of this infections disease in Mexico. 24,331 serum samples from women between 10 and 44 years old were collected during 1987-1988 from the 32 federal states. Samples were tested for Rubella Antibodies by use of hemagglutination inhibition with a titer 1:8 bring considered as positive; 79.96 per cent (CI 95%, 7.5-80.5%) of women were seropositive, seropositivity increased with age, from 69.26 per cent in the age group of 10 to 14 years old, to 87.84 per cent in the 40-44 age group. Seropositivity rates were lower in southern states than in northern states and, higher in urban areas that rural areas (82.4 vs 76.6%); statistical significative difference in seropositivity rates were found between girls less than 14 years of age in urban areas as compared to rural areas (74.7 vs 63.6%). Seropositivity rates were related to socioeconomic status only when high status group were compared lower status group (82.5 vs 77%). In addition, we observed a significative trend of increasing seropositivity as level of school education increased. In comparison to the 1974 national survey, this seroepidemiological survey showed a decreased seropositivity for all age groups, even with an increase in the number of susceptible women, particularly in the group less than 20 years old. This study offers seroepidemiologic information about rubella at a national and regional level.

The present study was designed in order to analyze our experience in surgical treatment of 18 patients with abdominal aortic aneurysm associate to a high surgical risk from 1982 (January-February) to 1988, both included. Selection criteria and surgical technical aspects were established. The patient age ranged from 60 to 82, with an average age of 75 +/- 7.5 years. The most frequently associated pathology was hypertension disease, followed by cerebrovascular disease and ischemic cardiopathy. Two patients died during surgical procedure. Fifteen patients, from the 16 surviving, suffered a complete thrombosis of their aneurysmatic sac one week after the induced thrombosis, by the ligature of afferent arteries of their aneurysm (iliac arteries). Only one patient suffered a second operation, 4 months after the initial procedure (partial exclusion) during which a total exclusion of aneurysm by infrarenal aortic ligature was performed. The successful operatory rate was of 14/15 (93.3%), with a mortality rate of 2/18 (11.1%). References are reviewed and our results commented.

The chemotherapy of amebiasis includes different substances with intra and extraintestinal action. Nowadays, metronidazole is the election drug by its high efficacy and low toxicity. Some therapeutic failures with metronidazole in patients with invader amebiasis and some reports of resistance to it, of certain strains of Trichomonas vaginalis and species of Bacteroides have caused an increased interest to do new in vitro evaluation of this compound and to search of new antiamebic drugs. The object of this work was to standardize with our conditions a microtechnique to evaluate the sensibility to metronidazole, experimented by trophozoites of three amebic strains of different virulence (HK9:NIH, HM1:IMSS, HM3:IMSS) and to compare the effect exerted by the drug on them. We modified the technique proposed by Cedeño and Krogstad in 1983. First we read the results in a half of the time employed by them (24h) and after, we fixed the trophozoites with 0.25% glutaraldehyde before of make the counts of them. We compared the number of cells in microcultures of 3.2 x 10(4) trophozoites incubated during 24h with metronidazole (from 0.008 to 1 micrograms/ml) with the obtained in control microcultures. Each one of the strains showed to have a characteristic sensibility to the drug (p less than 0.001), which was directly proportional to the concentration. The middle effective dose of HK9 and HM1 strains was 0.3 microgram/ml and of 1 microgram/ml for HM3 strain. This technique seems to be reproducible and could be useful to quantify the in vitro activity of antiamebic agents.

Objectives: a) to describe the frequency of pathogenic and nonpathogenic zymodemes of E. histolytica in asymptomatic carriers in rural Mexico, b) to identify the isoenzymatic pattern of the zymodemes and c) to measure the concordance of pathogenic zymodemes and positive serology., Design: Descriptive cross-sectional survey. Reference population: rural communities of the mexican highlands., Study Units: 2048 individuals from 341 families of 5 rural communities., Methods: From the local census of each community, 70 to 100 families were selected by random sampling. All members of each family were studied. After obtaining the consent the following activities were done: a) filling of a questionnaire about housing and sanitary condition and structure of the family; age, sex, literacy and digestive symptoms and illness during the previous 4 weeks, in each individual; b) a blood sample for serology (CEIP and IHA) and c) a stool sample for coproparasitoscopic analysis (CPS) and zymodemes identification, in each individual. Statistical evaluation was done by kappa index and receiving operating curves (ROC)., Main Results: there were 122/1730 (7.1%) CPS studies positive to E histolytica cysts, 100/1730 (5.8%) zymodemes isolated and 137/1886 (7.3%) positive serologic studies. Of the 100 zymodemes 30 had a pathogenic pattern, three had a mixture (pathogenic/nonpathogenic) and 67 had a non-pathogenic patterns. There were two (XVII, XVIII) patterns described for the first time in Mexico. Concordance between pathogenic zymodemes and positive serology (IHA greater than 1:128) was very low, Kappa = 0.05. ROC curves for IHA in pathogenic and non-pathogenic zymodemes showed little relationship between positive serology and pathogenic pattern., Conclusions: Although the frequency of positive serology, coproparasitoscopic studies and zymodemes identification was similar, the concordance between serology and the coprologic studies was very low. This disagrees with other reports, and deserves further investigation using methodologic standards in design.

Human amebiasis is a parasitic infection which involves asymptomatic as well as intestinal and extraintestinal symptomatic stages in individuals harbouring Entamoeba histolytica. Several factors have been proposed to explain the variability in the outcome of the disease. Among these are differences in virulence of E. histolytica strains and methods such as zymodeme analysis have been used to differentiate invasive from non invasive strains of this parasite (Sargeaunt and Williams, 1978). In order to establish a possible correlation between zymodeme analysis and serological data in human cases of amebiasis, a cross-sectional epidemiological study was carried out in the community area of Cadereyta, State of Queretaro, Mexico. In this study, fecal and serum samples from individuals were also tested by Indirect Hemagglutination assay (IHA) to determine antibody titre and by a standardized Electroimmunotransfer blot assay (EITB) for recognition of E. histolytica specific antigens. Zymodemes were determined in a total of 81 samples. Of these, 27 had a pathogen zymodeme (PZ) while 54 had a non pathogen zymodeme (NPZ). Values obtained by IHA varied from negative to titres up to 1:256 in serum samples tested. Reactivity to E. histolytica antigens determined by EITB was observed in all sera. Patterns of antigen recognition were complex and showed reactivity to several parasite molecules. Among these, components with M. Wt. of 165, 119, and doublets of 98-100 and 50-52 Kd were more frequently recognized by antibodies present in the sera tested. In general, antibody titres detected by IHA did not showed a direct correlation with zymodeme analysis. Samples with PZ or NPZ had similar variable levels of reactivity to E. histolytica antigens.(ABSTRACT TRUNCATED AT 250 WORDS)

The complexity of the clinical spectrum in human amebiasis and the high variability in laboratory methods used to detect Entamoeba histolytica infections have impeded the collection and evaluation of reliable epidemiological data. Thus, more sensitive, specific and standardized methods are needed in order to accurately identify infections with this parasite. An important step in the development of serological diagnostic methods is the identification and isolation of specific parasite antigens which are immunogenic in the host. In this work, we have standardized an electroimmunotransfer blot technique to characterize E. histolytica antigens recognized by antibodies present during human amebic infections. An important aspect was an investigation of technical variations in the preparation of cell lysates including the use of different protease inhibitors and solubilizing agents. The highest yield of protein was achieved by homogenization of trophozoites in the presence of 10 mM p-hydroxymercuribenzoate (pHMB) as a protease inhibitor and by lysis using Triton X-100 and a mixture of protease inhibitors. Recovery of degraded vs non-degraded proteins in the cell extracts was evaluated by gradient polyacrylamide gel electrophoresis. Both quantitative and qualitative differences were noted between the different methods of preparing soluble cell extracts. A more complete set of antigenic components was obtained by homogenization and use of pHMB. Thus parasite extracts prepared by this method were selected for protein transfer. In this, the optimal protein concentration was of 120 micrograms of protein per cm of gel width and efficient transfer of proteins to nitrocellulose sheets was achieved at 100 V for 2 hrs and at 4 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

The incidence of Clostridium difficile and its cytotoxic activity were determined in the feces of 122 children under 1 year of age. Samples were obtained from children receiving antibiotics and with (52 cases) or without (26 cases) diarrhea, from children with diarrhea who did not receive antibiotics (22 cases), and from healthy children (22 cases). Isolation of C. difficile in feces from children in all groups was similar (mean 23.4%) except for the group with non-antibiotic-associated diarrhea (4.5%). In both groups of children receiving antibiotics, with or without diarrhea, the cytotoxin was detected in 7.6% of the cases. In the group with non-antibiotic-associated diarrhea, none of the samples was positive for cytotoxicity. In healthy children, cytotoxin was positive in 4.5% of the cases.

800 samples of pharyngeal exudate were taken from healthy children and 28 healthy intrafamilial contacts of children with meningitis caused by H. influenzae type b. H. influenzae type be was isolated in 8.7 per cent of nursery children, H. influenzae type e in 0.12 per cent and non typifiable H. influenzae in 5.8 per cent. On intrafamilial contacts, 32 per cent had H. influenzae type b and non typifiable in 3.5 per cent. Percent age of ampicillin resistant H. influenzae type b was 14 per cent. No strains were found resistant to chloramphenicol. S. pneumoniae was isolated in 37 per cent of pharyngeal exudate samples. 25.5 per cent of strains tested were penicillin sensitive; 74.5 per cent has a decrease sensitivity. Based on these results we consider chloramphenicol to the the first drug of choice for treatment of severe H. influenzae infections and penicillin for S. pneumoniae infections recommending in the latter higher doses when dealing with central nervous system infections.

The per centum distribution of T and B lymphocytes was determined in 30 full term newborns showing adequate development for their gestational age and in 42 full term newborns showing in utero malnutrition. A significant decrease (p less than 0.001) of both lymphocytic subpopulations was found in the in utero malnutrition group. The possibility of a decreased efficiency of the immune response in this group of patients is discussed.

Five different microbiological markers (biotyping, antimicrobial susceptibility, heavy-metal susceptibility, klebocin susceptibility and number of extrachromosomal DNA fragments) were utilized in order to distinguish between Klebsiella ozaenae strains arising from a nosocomial infection outbreak and strains of some species isolated from hospital environment. Antimicrobial susceptibility pattern to 13 different antibiotics was the most reliable maker, because 85% of the outbreak strains shown resistance to 8-10 antibiotics and only two strains of hospital environment had similar pattern. Sensitivity for this marker was 85.0% specificity 93.5% and positive predictive value of 89.5%. Other markers were less efficient with a positive predictive value of 79.2%, for biotyping, 70.4% for klebocin susceptibility, 69.2% for number of extrachromosomal DNA fragments and 60.6% for heavy-metals susceptibility. We discuss the applicability of each one of these markers in different circumstances.

During measles infection in human beings, depression of cellular immunity appears. The authors studied several groups of children with measles complaining of various degrees of malnutrition in terms of rosette forming lymphocytes in peripheral blood; marked reduction of T lymphocytes were seen in all of the groups during the acute stage of the disease, that persisted up to two weeks after the exanthematous stage. When comparison was established of eutrophic and 1st degree malnourished children with those affected with 3rd degree malnutrition, differences were found in the recovery of the number of rosett-E forming cells.

The purpose of this study was to determine if there was any relationship between the socio-economic level of patients and the colonization of the stomach by Campylobacter pyloridis. We have studied 256 patients who underwent esophagogastroduodenoscopy because they had upper gastrointestinal symptoms of this group, 143 from Arzobispo Loayza Hospital (38 males and 105 females) and 122 from the private practice of three of the authors (77 males and 45 females). The ages ranged from 16 to 75 years (media 45.5 years). In each case biopsies of the antrum were taken and stained with hematoxylin-eosin and Warthin-Starry Silver Stein. We classified patients into 3 different groups based on where they lived: nuclear districts, intermediate districts, and peripheral districts. In Lima, the type of district from the patient strongly correlates with their socio-economic status. The hospital and private patients differed significantly in the distribution of which type of district their patients came from. In contrast there was a no marked similarity between these two patient groups in their rate of colonization by Campylobacter pyloridis. It appears that the socio-economic level of peruvian patients, presenting to clinic with symptomatic gastro-intestinal disease is not an important factor with pyloric campylobacter infection.

The sensitivity to chloramphenicol and ampicillin of 127 strains of H. influenzae was tested. One hundred and one strains were obtained from the pharyngeal exudate of 828 healthy carriers under 5 years of age and 26 from the spinal fluid of children with meningoencephalitis. Sixty per cent of isolations corresponded to type b; 40 per cent were non typical and we only identified one type e. All H. influenzae obtained from spinal fluid corresponded to type b. The frequency of healthy carriers was greater in intrafamily contacts of children with H. influenza meningoencephalitis (p less than 0.01). Percentages of resistance to ampicillin varied between 6 and 23% for the different groups; we found no statistical difference among them (p less than 0.2). The prevalence of H. influenza resistant to ampicillin in the population studied was 1.2% for type b strains and 0.2% for non typical bacteria. Fourteen per cent of penicillin resistant type b strains were identified; all 127 isolations were to chloramphenicol; therefore, we recommend this drug instead of ampicillin for the treatment of H. influenza infections, with the exception of acute otitis media.

This study describes the epidemiology of acute respiratory infections (ARI) in a sample of rural population of México. The study includes 137 communities from all over the country: 51 with 5001 to 15000. In each community ten families with one child under one year of age were followed. Each family was child under one year of age were followed. Each family was visited weekly by one physician from the local IMSS-COPLAMAR clinic in order to register frequency and characteristics of ARI in each family member. We followed 1359 families and observed 4796.9 persons-year. Eight thousand and two episodes of ARI were observed. The relative risk of getting ARI in children below two years of age was 2.8 and in severe malnourished was 1.8. The frequency of ARI was higher in large communities than in small ones. Eight six point eight percent of the episodes were upper respiratory infections, 95.3 percent of the cases cured, 4.6 became chronic and there were four deaths. Mortality rate was 0.8 per 1000 persons-year. Sixty nine point eight percent of the cases received antithermics, 49.3 percent antihistaminics and, 48.6 percent antibiotics.

The study included 22 patients with meningoencephalitis and hypertensive cranial syndrome from cerebral edema. Mannitol was given to 13 cases and dexamethasone to 9. There were three therapeutic failures in the group given mannitol and none in that of dexamethasone (p greater than 0.05). Both drugs showed similar effect in the duration of the hypertensive cranial syndrome (39-44 hrs). Patients treated with mannitol showed hyponatremia after 48 hours. No untoward effects appeared in patients given dexamethasone.

Two cases are reported of severe type of S. aureus cellulitis which led to the production of mycotic aneurysms of the internal carotid artery. This situation has not been previously described in the literature. Analysis is made of the infectious pathogenesis of mycotic aneurysms.

Hearing loss (HL) was prospectively studied in 236 children with meningitis using brainstem auditory evoked responses. Hearing loss was detected in 38 (16.1%) in the acute phase of the disease and in 10 (5.2%) of 193 patients who were tested 6 months later. Hearing loss was more frequent and more severe in patients with bacterial meningitis (25.4% in the acute phase, and 8% 6 months later) than in patients with viral and tuberculous meningitis. In half of the affected cases the auditory lesion was bilateral. Follow-up was possible in 32 patients with early postmeningitic HL. Ten (31.2%) had permanent HL while the remaining 22 (68.7%) recovered normal hearing. Severe initial losses tended to be permanent, whereas minimal and intermediate losses were generally reversible and patients recovered completely in 1 to 6 months. The high incidence of HL in bacterial meningitis suggests that any one of the existing methods of auditory screening should be performed in all patients during the convalescent period.

Cerebrospinal fluid from patients with tuberculous, pyogenic, and viral meningitis, as well as from appropriate control individuals, were assayed for immunoglobulin G and immunoglobulin M antibody activity to Mycobacterium bovis BCG by an enzyme-linked immunosorbent assay. BCG linked covalently to plastic disks served as the antigen in a classical indirect enzyme-linked immunosorbent assay. A significant difference was found between the tuberculous meningitis group and the nontuberculous meningitis and control groups. All samples from the tuberculous meningitis group gave a positive reaction, and none of the known negative samples gave false-positive reactions. Because of its sensitivity, specificity, and predictive value, this test may be useful in the early diagnosis of tuberculous meningitis.

Samples of otic secretion for culture were taken to 50 children with suppurative chronic otitis media; two techniques were followed: with a cotton swab from the external meatus or with a sterile metal aspirator, through the tympanic perforation under microscopic control. To 20 of them with unilateral chronic otitis media, a swab with product from the external meatus of the healthy ear was also taken; in 65% of the latter, the same germs were found in both ears, but when the sample was taken with the aspirator, only in 15% were the germs the same (p less than 0.01). Two or more germs were isolated in 54% of the ears following the technique of the swab and in 32% with the aspiration. The predominant microorganisms with the swab technique were gram-positive cocci (S. epidermidis 48% S. aureus 16%); while the aspiration technique reported gram-negative germs in 96% of cultures (Proteus sp. 42%, Pseudomonas sp. 30% and S. aureus only in 14%). We believe that the sample obtained with a swab has a high degree of contamination with the normal flora of the external meatus; therefore, it should be relinquished.