Some techniques available at our laboratory were tested for their ability to aid in the morphological diagnosis of hydatid elements (Echinococcus granulosus [“Taenia echinococcus”]) isolated from cysts in humans and sheep. Unstained, methanol-fixed hooklets were fluorescent, most starkly so under violet light (excitation filter wavelength, 405 nm; long-pass filter wavelength, 495 nm). Auramine-rhodamine and Gram procedures failed to stain hooklets. Ziehl-Neelsen stain yielded indifferent results when organisms were viewed under transmitted light but resulted in a surprisingly intense red fluorescence when organisms were viewed under green light (excitation, 546 nm; long pass, 590 nm). Wheatley trichrome stain gave better and more uniform results than fuchsin. Ryan trichrome blue stain was the best under transmitted light; hooklets stained uniformly and intensely and were easily distinguishable from the background. Very satisfactory results were also obtained with a much simpler procedure (modified Baxby technique: no fixation, steaming hot 1% safranin for 2 min, and malachite green for 30 s). Therefore, Ryan and modified Baxby stains are recommended for the examination of E. granulosus under transmitted light. For fluorescence microscopy, Ziehl-Neelsen stain under green excitation light, or violet light with no staining, is also very useful. Epifluorescence microscopy is especially convenient for examining samples concentrated by filtration, as it renders the filter pores inconspicuous.

The incidence of astrovirus infection in children less than 10 years of age with gastroenteritis in the city of Zaragoza, Spain, was analysed during a 12-month period. A total of 718 stool samples obtained from 534 children were examined. In 401 samples no routinely searched for pathogenic organism was detected; these specimens were then tested for the presence of astrovirus antigens. Astrovirus was detected in the samples of 15 (5.5%) patients, a detection rate similar to that recognised for Yersinia enterocolitica and Cryptosporidium spp. All children with confirmed astrovirus infection had diarrhoea (median duration, 9 days), 11 experienced loss of appetite, 5 vomiting, and 4 fever. The incidence of astrovirus infection reported here indicates that Spanish children suffering from gastroenteritis should be routinely screened for the presence of astrovirus.

Eighty cases of typhoid fever occurred in San Antonio, Texas, with dates of onset from August 18, 1981, to October 26, 1981. Preliminary epidemiological investigations of the first 24 cases suggested a Mexican food takeout restaurant as the common source. A case-control study confirmed this association (P less than or equal to .001). Barbacoa , a mixture of muscle, lips, ears, tongue, and eyes from steamed bovine heads, was identified as the source of Salmonella typhi (P = .03). S typhi was cultured from the stool of one of 31 restaurant employees. Closure of the restaurant resulted in termination of the outbreak within a single incubation period. The restaurant was allowed to reopen after the remaining employees had demonstrated lack of excretion of S typhi in stools. This outbreak represents the largest restaurant-associated typhoid fever outbreak reported in the United States in greater than 50 years.

A study was conducted to assess the value of a combination of two culture methods for isolation of Campylobacter spp. from Spanish children. Seven hundred twenty-nine diarrhoeal stool specimens from 599 patients were examined for Campylobacter spp. by culturing them on charcoal cefoperazone deoxycholate agar and on blood agar with a membrane filter. One hundred sixteen Campylobacter strains were isolated from a total of 108 specimens; 75 (64.6%) were Campylobacter jejuni, 32 (27.5%) were Campylobacter coli, 8 (6.8%) were non-typeable, and one (0.9%) was Campylobacter upsaliensis. Campylobacters were isolated from 99 positive samples using charcoal cefoperazone deoxycholate agar alone. The filtration technique alone yielded only 86 positive samples. Seven specimens yielded different Campylobacter spp. with different media. The only catalase-negative strain was recovered using the filter method. The combination of the selective medium with the filter method increased the isolation rate of Campylobacter strains by 14.1%. Isolation rates of campylobacters using the filter method were similar to those reported in European studies, in which a similar frequency of Campylobacter upsaliensis was observed. The addition of a filter method for routine laboratory isolation of campylobacters should be considered in selected age groups (in children < 10 years of age) or in areas where catalase-negative or weakly-positive Campylobacter strains may be of epidemiological significance.

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