The detection of cholera vibrios in Calcutta waters: the River Hooghly and canals

1. Before undertaking a bacteriological survey of the waters of the Hooghly River and the associated canals a detailed epidemiological study over the past 20 years of cholera, as it affected the individual administrative wards of Calcutta, was undertaken. Sampling points were selected in accordance with the results of this study. Samples of water from the various points were collected at intervals extending from December 1958 to August 1959 in 2½–5 l. amounts. The whole sample in each case was filtered through special filter pads. The pads were first cultured in an enrichment medium from which plate cultures were subsequently made for colony isolation, serological and biochemical examination.

2. The sampling points on the canals were all adjacent to areas where the local endemicity was judged to be high; other points were by bathing ghats, etc. A total of eighty-nine samples covering all the sampling points were examined and Vibrio cholerae were isolated from twelve of these samples, eight of which came from twenty-six samples collected from two sampling points on the Chetla and Circular Canals, respectively.

3. The positive isolations were spread fairly evenly over the whole period of the study which covered both epidemic and non-epidemic periods including the monsoon. Although the incidence of cholera in Calcutta may fall to a low level during non-epidemic periods cases continue to occur throughout the year and the relationship of the maintenance of the infection in the city to the continuous potential infectivity of the open natural waters of Calcutta is discussed.

Cholera reveals helminthiasis problem

Cholera has now lasted for about 6 months in our hilly region in Mwanza, Tanzania. The heavy rains coupled with the poor sanitary conditions and sewage disposal system have worsened the situation. The pit latrines used by the majority of low-income people are either not adequately and properly used for excreta disposal or they overflow. At our regional referral and consultancy hospital we were, for a period, receiving cholera cases which should have been managed in isolation at other centers. (This situation has now been rectified.) Some of the children with cholera either vomited or passed Ascaris lumbricoides in their rice water-like stools. Previously, these children were not being treated for ascariasis. Practical steps can be taken to reduce the transmission of fecal-borne infections. For more than 30 years we have failed to have a latrine for each family; we should aim for at least one for every 10 households. The provision of clean tap-water and facilities to deworm pre-school children would also be welcomed. In addition, medical officers should actively instruct the community in the science of hygiene.

[Current status of gastrointestinal infection in Japan--with special reference to enterohaemorrhagic Escherichia coli infection]

The annual incidence of gastrointestinal infections such as bacillary dysentery, typhoid fever and paratyphoid fever has declined markedly since the early 1960s. However, in parallel with the increase of international travel, the incidence of imported cases from abroad has recently tended to increase. Moreover, similar to North America and Europe, food-borne infections such as Salmonella food poisoning due to serovar Enteritidis and enterohaemorrhagic Escherichia coli infection has increased dramatically recently. In this paper, the current trend of gastrointestinal infections in Japan was discussed from the epidemiologic and bacteriologic view points.

INTRADERMAL CHOLERA VACCINATION

The protection afforded by cholera vaccine administered by the intradermal route, and demonstrated by active and passive mouse protection tests, active guinea-pig protection tests, and agglutination titres, is excellent and equal to that given by subcutaneous inoculation.

It is suggested that cholera vaccine administered by the intradermal route would greatly reduce the incidence of reactions which occur when the vaccine is given subcutaneously.

A new type of conjugative transposon encodes resistance to sulfamethoxazole, trimethoprim, and streptomycin in Vibrio cholerae O139

Vibrio cholerae O139 is the first non-O1 serogroup of V. cholerae to give rise to epidemic cholera. Apparently, this new serogroup arose from an El Tor O1 strain of V cholerae, but V. cholerae O139 is distinguishable from V. cholerae El Tor O1 by virtue of its novel antigenic structure and also its characteristic pattern of resistances to the antibiotics sulfamethoxazole, trimethoprim, streptomycin, and furazolidone. We found that the first three of these antibiotic resistances are carried on an approximately 62-kb self-transmissible, chromosomally integrating genetic element which we have termed the SXT element. This novel conjugative transposon-like element could be conjugally transferred from V. cholerae O139 to V cholerae O1 and Escherichia coli strains, where it integrated into the recipient chromosomes in a site-specific manner independent of recA. To study the potential virulence properties of the SXT element as well as to improve upon the live attenuated O139 vaccine strain Bengal-2, a large internal deletion in the SXT element was crossed on to the Bengal-2 chromosome. The resulting strain, Bengal-2.SXT(s), is sensitive to sulfamethoxazole and trimethoprim and colonizes the intestines of suckling mice as well as wild-type strains do, suggesting that the SXT element does not encode a colonization factor. Derivatives of Bengal-2.SXT(s) are predicted to be safe, antibiotic-sensitive, live attenuated vaccines for cholera due to the O139 serogroup.

Case report: cholera in a preterm neonate

Falling standards of sanitation resulted in the first outbreak of cholera in Lusaka, Zambia, during the rainy season, February 1990. A total of 2166 cases were handled with 128 (5.9%) deaths. One hundred and eight (108) children, including one preterm neonate, were admitted to the University Teaching Hospital. The neonate went to the Neonatal Intensive Care Unit.

Alanine-based oral rehydration solution: assessment of efficacy in acute noncholera diarrhea among children

This randomized, double-blind trial determined whether adding 90 mmol/L of alanine with a reduction in glucose to 90 mmol/L (alanine ORS) improves the efficacy of the standard oral rehydration solution (WHO-ORS). One hundred twenty-nine males aged 3-48 months with weight for length greater than or equal to 70% of NCHS, diarrheal duration less than or equal to 96 h, and clinical signs of mild to moderate dehydration were randomly allocated to either treatment group. During 0-6 h of treatment, ORS was offered at 120 ml/kg for rehydration without food or water. Beyond 6 h, ORS was offered as a volume-to-volume replacement for stool losses and a mixed diet of uniform composition was offered in amounts standardized for body weight. The most frequently isolated pathogens in alanine ORS and WHO-ORS groups were rotavirus (42 and 48%, respectively) and enterotoxigenic Escherichia coli (15 and 12%, respectively). In the 0-6 h period when food was withheld, median urine output in ml/kg (8;5, p less than 0.05) and percentage decrease in total serum solids (9:7%, p = 0.06) was significantly greater in alanine ORS than in WHO-ORS; median ORS intake and stool output were marginally lower in the alanine group but the differences were statistically not significant. Between 0 h and recovery, although the median values for duration of diarrhea (56.5 and 65.0 h), ORS consumption (260 and 323 ml/kg), and stool output (188.4 and 216.3 g/kg) were lower in the alanine ORS group, these differences with the WHO-ORS group were not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Surveillance of patients attending a rural diarrhoea treatment centre in Bangladesh

In May 1983, a surveillance system was set up at a rural diarrhoea treatment centre of the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) to study a 20% systematic sample of all admissions. Between May 1983 and April 1984, 2,635 patients were studied. A recognized enteric pathogen was detected in 69% of the patients screened, 15% of whom had a mixed infection. Vibrio cholerae 0: 1 was the most common enteropathogen detected (39%), followed by enterotoxigenic Escherichia coli (ETEC) (14%), Shigella spp. (11%), and Campylobacter jejuni (11%). Detection of C. jejuni was highest in infants, Shigella spp. in children between 1-4 years and V. cholerae 0:1 in children between 3-9 years of age. 75% of patients presented with watery diarrhoea, a presentation that was significantly more common in patients infected with V. cholerae 0:1 (94%) and ETEC (88%). Bloody diarrhoea was the presenting complaint in 18% of all patients, but in 65% of patients in whom Shigella spp. was isolated. Although 91% of patients reported that they had prior experience of use of oral rehydration therapy (ORT), 54% of the patients came to the treatment centre with no or mild dehydration and more than half of them did not use ORT before coming to the treatment centre. Most of these patients could have been safely treated at home if ORT could be made available and acceptable.

Dissemination of health information among rural dwellers in Africa: a Ghanaian experience

This paper looked at how effectively the Ghanaian Ministry of Health disseminated health information within the country. Standardized questionnaires were administered to samples from two villages to find out how they obtained information about four selected health topics--cholera, immunization, ORT and AIDS--and what they knew about these health topics. We found that respondents relied almost equally on conversation with family and friends on the one hand and radio on the other, for information on the selected health topics. Health workers and a traditional communication channel, the 'town-crier', also played significant roles. Our data appeared to indicate that messages on the four selected health topics were not being properly and accurately conveyed and suggestions aimed at redressing this situation were put forward.

A case report of acute obstructive suppurative cholangitis in a non-0-1 Vibrio cholerae biliary carrier

A case report is presented of a 73-year-old male who was seen with fever, jaundice, abdominal pain and central nervous system depression. He failed to respond to intensive antibiotic therapy, and subsequently acute obstructive suppurative cholangitis fully developed. Upon laparotomy, the patient's gallbladder was found to be enlarged with the bile from the gallbladder and bile duct itself containing a high pus content. Its cultured organism revealed non-0-1 Vibrio cholerae. To our knowledge, no prior case of acute obstructive suppurative cholangitis in a non-0-1 Vibrio Cholerae biliary carrier has been reported in Japan.

Vibrios and Aeromonas

There are many similarities in the Vibrionaceae that cause human illness in the United States (see Table 1). Vibrios are characteristically indigenous to marine, estuarine, and brackish environments. They are distributed mainly in Gulf of Mexico coastal water, and these organisms "bloom" when the water is warm. Outbreaks of disease in humans frequently occur in summer, coinciding with multiplication of vibrios in warm water. Sporadic cases and small outbreaks of cholera continue to occur in persons living on or near the Gulf of Mexico, but infection in most persons is unrecognized. In fact, more serious and frequent illnesses result from V. vulnificus wound infections and from gastroenteritis caused by vibrios other than V. cholerae 01. Underlying hepatic or neoplastic disease (especially leukemia) apparently increases the likelihood and severity of illnesses caused by V. vulnificus and Aeromonas. Some Vibrionaceae produce clinical illness by means of enterotoxins identical or similar to cholera toxin. For many others, hemolysins, cytotoxins, and other exotoxins are necessary to produce disease; the importance of these virulence factors often is not known or the importance of these virulence factors often is not known or is of doubtful significance. Also, purported pathogenicity as demonstrated by animal models, such as fluid accumulation in ligated ileal loops, is quite nonspecific and needs to be interpreted cautiously. For Plesiomonas, a mode of pathogenesis has not been discovered. Eating raw shellfish (frequently raw oysters) has been linked epidemiologically to enteric infections with most of these bacteria; foreign travel and exposure to seawater are other frequently observed epidemiologic associations with infection. Foreign travel, particularly to the Yucatan Peninsula of Mexico, has been strongly associated with the acquisition of non-01 V. cholerae and Plesiomonas organisms. Most Vibrionaceae in the United States are susceptible in vitro--and illnesses from them are responsive--to tetracycline, trimethoprim-sulfamethoxazole, and other common antimicrobial agents. However, as for other bacteria that cause diarrhea, the main treatment for uncomplicated disease is the judicious replacement of fluids and electrolytes lost in diarrhea. A loose network of surveilance for these organisms comprises hospital and public health laboratories in Gulf coastal states that plate diarrheal stools on TCBS agar. As recognized pathogens are more assiduously screened for, and as newly identified vibrios are definitely included or excluded as enteric pathogens, the clinical importance of these members of the Vibrionaceae family should become clearer.

Rapid detection of Vibrio cholerae O:1 by motility inhibition and immunofluorescence with monoclonal antibodies

Monoclonal antibodies against the group and type specific antigens of Vibrio cholerae O:1 lipopolysaccharide were used for the rapid detection of Vibrio cholerae strains by motility inhibition and immunofluorescence. Motility inhibition of live Vibrio cholerae O:1 was obtained with group specific monoclonal antibodies. Monoclonal antibodies against the type specific antigens B (Ogawa) and C (Inaba) inhibited motility of strains of homologous serotypes only. Indirect immunofluorescence of heatfixed bacteria with monoclonal antibodies and fluorescein-isothiocyanate conjugated rabbit anti-mouse immunoglobulin was also shown to be suitable for the rapid detection of Vibrio cholerae O:1. Both tests were highly specific and no cross-reactions were observed with strains of non-O:1 vibrios, Escherichia coli or Salmonella spp. tested. However, a weak fluorescence of some Ogawa strains was observed when high concentrations of Inaba specific monoclonal antibodies were used.

Entrance of cholera enterotoxin subunits into thymus cells

Analysis of the staining of cholera enterotoxin on the surface of cells with specific antibodies against each subunit of cholera enterotoxin, using a fluorescence-activated cell sorter and electron microscopy, showed that not only subunit A but also subunit B penetrates the cell membrane. The detection of subunits inside the cell was facilitated by the use of saponin, an agent that increases membrane permeability.

Simple adult rabbit model for Vibrio cholerae and enterotoxigenic Escherichia coli diarrhea

We developed an adult rabbit model for enteric infection by Vibrio cholerae and enterotoxigenic Escherichia coli. The cecum of each animal was first ligated to prevent it from retaining fluid secreted by the small intestine. A temporary reversible obstruction (a slip knot tie) of the small bowel was introduced at the time of challenge and removed 2 h later. With this modification, we were able to elicit a massive and usually fatal cholera-like diarrhea in adult (3.5- to 6-lb [1.6- to 2.7-kb]) animals challenged with V. cholerae. Animals challenged with enterotoxigenic E. coli also developed diarrhea which was severe and watery but less explosive and less rapidly fatal than that produced by V. cholerae. The susceptibility of animals in this model to infection by V. cholerae was similar to the susceptibility of infant rabbits challenged intraintestinally. The death rate was almost 25% when 10(3) Vibrio cells were given and 90% or more when the dose was greater than or equal to 10(6) cells per animal. We designated this procedure the RITARD (for removable intestinal tie-adult rabbit diarrhea) model.

Postnatal development of jejunal sucrase: independence from cyclic AMP

It has previously been shown that jejunal sucrase activity becomes increasingly responsive to glucocorticoids between the postnatal ages of 4 and 15 days. This study examines the possibility that cyclic AMP is the mediator of the increasing responsiveness. When dibutyryl cyclic AMP was administered concomitantly with glucocorticoid to rat pups aged 6 days, there was no enhancement of sucrase activity in pups sacrificed either 30 or 54 h later. To check for short-lived effects of cyclic AMP, pups aged 5 days were pretreated with glucocorticoid for 2 days to elicit sucrase activity, then received dibutyryl cyclic AMP by injection and were sacrificed 1, 3 and 6 h later. Once again there was no effect of cyclic AMP on sucrase activity. The final approach was to use cholera enterotoxin to stimulate epithelial adenylyl cyclase in jejunal segments in vivo. Under these conditions the stimulation of fluid secretion served as positive evidence that intracellular concentrations of cyclic AMP were elevated. However, once again there was no stimulation of sucrase activity. It is concluded that cyclic AMP does not mediate the increasing responsiveness of the developing intestine to glucocorticoids.

[Regressive dysautonomia associating orthostatic hypotension with an invariable pulse and choleriform diarrhea (author's transl)]

The authors describe a case of very severe orthostatic hypotension with an invariable pulse arising during the course of considerable motor diarrhea. The diagnosis of primary dysautonomia was made only after eliminating the many organic causes of diarrhea: microbial, toxic, tumoral endocrine including diabetes. Shy and Drager's syndrome was rejected because of the spontaneously regressive course after a period of 4 years, the patient having had no further signs of orthostatic hypotension.

Gastroenteritis: etiology, pathophysiology and clinical manifestations

The infectious etiologic agents of gastroenteritis are manifold and have only recently been studied in greater depth. Part of the problem in studies pertaining to diarrhea is the difficulty in identifying fecal "pathogens" among an enormous number of indigenous fecal microorganisms. Finally, the recognition of the pathogenicity of enterotoxins has created an awareness of the complexity of gastrointestinal physiology with host-parasite interactions.