First report of Dactylogyrus formosus from India: a case of co-existence with Paradactylogyrus catlaius causing mass mortality in Indian major carp, Catla catla

The family Dactylogyridae, known for its role as a frequent pathogen in Cyprinids, was identified in a case of mass mortality involving Catla catla fingerlings (measuring 6.5 ± 2.0 cm and weighing 40.5 ± 10 g) in West Bengal, India. Microscopic examination revealed the presence of two co-existing parasites, Dactylogyrus formosus and Paradactylogyrus catlaius, attached to different sections of the gill filament. Despite their coexistence, these parasites exhibited marked differences in their haptoral hard parts, genital organs, and preferred habitats. Molecular analysis of the Internal Transcribed Spacer 1 and 4 genes indicated more than 90% similarity between the detected parasite and D. formosus previously reported in China. Histopathological observations illustrated the parasites' specific attachment to the distal end of the primary gill lamellae, gradually causing destruction to a maximum number of secondary lamellae. Internally, infiltration of eosinophilic granular cells was observed in gill and kidney blood vessels, while the liver exhibited hepatocytes filled with hemosiderin. The infected fish were treated for 24 h with a safe dose of common salt (5.6 ppt) and albendazole (62 ppm). The survivability rate was significantly higher (p < 0.05) in both treated groups compared to the control. Interestingly, the group treated with common salt showed superior results compared to the albendazole-treated fish. This study presents the sympatric speciation of D. formosus in a new host (C. catla) and explores its host specificity, histopathology, and treatment methods. This case marks the first report of D. formosus causing substantial mortality in cultured Catla in India, alongside the coexistence with Paradactylogyrus catlaius.

Myxozoan fish diseases: possible treatment and zoonoses

Myxozoan parasites pose huge threat to wild and cultured fishes and reported to cause heavy mortality, retarded growth and post-harvest quality degradation. It is one of the highly divergent groups of parasites which infects skin, gill, muscle, cartilage and internal organs of host fish and the severity of pathology varies depending on the water temperature, species of fish, site of tissue infection and immune resistance of the individual host. Most infections are difficult to treat, as they can easily evade host cellular and humoral defence mechanisms by proliferating or migrating through immune compromised sites of the host and forming large plasmodia encapsulated by the host cellular elements. This spore-forming parasite is harmless to humans but often detected in faecal samples of immunosuppressed humans. The incidences are mostly associated with the consumption of infected fish having a high concentration of spores which causes diarrhea and stomach pain. Currently, there are no immunostimulants or vaccines available for controlling these parasites, however, fumagillin is the drug of choice in fish for controlling this parasitic infection. Excessive usage of fumagillin causes tissue damage and retarded growth in fish, hence feed incorporation of this antibiotic in proper dose is essential for effective treatment. In this review detailed information on the diseases caused by myxozoan parasites in fishes and their zoonotic potential is discussed.

Beyond pregnancy--the neglected burden of mortality in young women of reproductive age in Bangladesh: a prospective cohort study

OBJECTIVE

To describe proportionate mortality and causes of death unrelated to pregnancy.

DESIGN

Prospective cohort study.

SETTING

Rural northwest Bangladesh.

POPULATION

A cohort of 133,617 married women of reproductive age.

METHODS

Verbal autopsies were conducted for women who died whilst under surveillance in the cohort trial. Physician-assigned causes of death based on verbal autopsies were used to categorise deaths.

MAIN OUTCOME MEASURES

The proportion of deaths due to non-communicable diseases, infectious diseases, injury or pregnancy.

RESULTS

Of the 1107 deaths occurring among women between 2001 and 2007, 48% were attributed to non-communicable diseases, 22% to pregnancy, 17% to infections, 9% to injury and 4% to other causes.

CONCLUSIONS

Although focus on pregnancy-related mortality remains important, more attention is warranted on non-communicable diseases among women of reproductive age.

Assessment of occupational and patient dose from diagnostic and therapeutic radiation exposure using thermoluminescent dosimetry

Radiation doses of occupational personnel exposed from diagnostic x rays, therapeutic installations, and patients were measured using thermoluminescent dosimeters. The monthly occupational doses from diagnostic x ray ranged from 0.1076 mSv to 0.5774 mSv, and those from therapeutic treatment ranged from 0.365 mSv to 0.657 mSv, which is within the dose limit recommended by ICRP 60. The patient organ doses were evaluated and found to range from 0.0615 mSv s(-1) to 2.8823 mSv s(-1) for gonad, 0.3676 mSv s(-1) to 2.1088 mSv s(-1) for thyroid, and 0.00972 mSv s(-1) to 4.01 mSv s(-1) for eyes.

Observations questioning a protective role for breast-feeding in severe rotavirus diarrhea

To investigate whether breast-feeding protects children against rotavirus diarrhea (RVD), we compared rates of breast-feeding by age and enteric pathogens among 2,276 children with diarrhea 0-4 years of age who attended a diarrhea hospital in Bangladesh. Infants 0-5 months were less likely to be breast-fed than children 6-11 months of age suggesting that some protection against diarrhea with all agents was associated with early breast-feeding. In every age group studied, breast-feeding was more common among children with RVD than among children with non-RVD whereas it was less common among children with cholera and shigellosis. Twenty percent of breast milks consumed by infants less than 1 year of age had high levels of neutralizing activity (greater than or equal to 320) to the Wa strain of rotavirus but this activity did not appear to be protective since the 30 infants with RVD consumed milk which had titers that did not differ significantly from those consumed by 44 infants with diarrhea of other cause. Despite the prolonged breast-feeding which is common in Bangladesh, the mean age of hospitalization with RVD is approximately the same as in countries where the duration of breast-feeding is quite short. None of these 3 independent observations support a protective role for breast-feeding against rotavirus diarrhea after the first months of life.

Breast feeding as a determinant of severity in shigellosis. Evidence for protection throughout the first three years of life in Bangladeshi children

Little is known about the effect of breast feeding upon the severity of illness due to specific diarrheal pathogens. Using a systematically sampled and evaluated population of children aged less than 3 years, who attended a diarrheal disease hospital in Bangladesh, the authors performed a case-control study that assessed whether breast feeding reduces the severity of illness in shigellosis. From 540 children presenting with shigellosis between 1980-1982, they created a group of cases (n = 53) with severe illness and controls (n = 487) with non-severe illness. Overall, the odds ratio relating breast feeding to the severity of shigellosis (0.49, p = 0.01) suggested a substantial mitigating effect of breast feeding upon clinical severity. The high degree of protection against severe shigellosis was evident for breast-fed children up to 35 months of age, as well as for children at high risk for death because of severe malnutrition or measles. Because shigellosis continues to account for substantial morbidity and mortality in children in developing countries, the results support prolonged breast feeding in these settings.

Changing pattern of resistant Shiga bacillus (Shigella dysenteriae type 1) and Shigella flexneri in Bangladesh

Shigella dysenteriae type 1 (Shiga bacillus) has made a dramatic comeback in Bangladesh after 10 years when Shigella flexneri was the dominant serogroup. Whereas S. flexneri showed little increase in resistance to the commonly used antimicrobial agents--namely, trimethoprim-sulfamethoxazole (TMP-SMX) and ampicillin-over the years, S. dysenteriae type 1 underwent rapid changes with regard to sensitivity pattern during the last two years. The first TMP-SMX-resistant strain of S. dysenteriae type 1 was detected in September 1982; however, by mid-1984 most strains were resistant while retaining sensitivity to ampicillin. During this period, the ratio of S. flexneri to S. dysenteriae type 1 narrowed from 0.15 to 1. Such propagation of high resistance to TMP-SMX might have been due to widespread use of the drug imported into the country in large quantities. Resistance to ampicillin is increasing rapidly, particularly in S. dysenteriae type 1.

Value of stool examination in patients with diarrhoea

Findings of stool examinations in 1593 patients with diarrhoea due to a single enteric pathogen--enterotoxigenic Escherichia coli rotavirus, Shigella, Campylobacter jejuni, Vibrio cholerae 0:1, Entamoeba histolytica, or Giardia lamblia--were reviewed to determine how well they predicted the agent associated with the diarrhoea. Specimens were examined visually for blood and mucus, tested for pH, and examined under a microscope for the presence of red and white blood cells, parasites, and stool fat. Although visible blood was more common in specimens from patients infected with Shigella (51%) and Ent histolytica (39%) than in those from patients infected with other agents (6%; p less than 0.01), patients infected with Shigella were most likely to have numerous faecal leucocytes (greater than 50/high power field: 39% v 8% of all patients and 7% of patients infected with Ent histolytica, p less than 0.01 in both cases). Patients infected with enterotoxigenic E coli, rotavirus, V cholerae 0:1, or C jejuni had loose stools with fewer red or white cells. Patients infected with rotavirus and C jejuni were more likely to have acid stools with 3 to 4+ fat, but these findings were related to young age and breast feeding. Stool examination is most useful in establishing a diagnosis of dysentery and in helping to distinguish between patients infected with Shigella and Ent histolytica; it is of limited usefulness in discriminating between pathogens causing watery diarrhoea.

Enteric fever in patients admitted to a diarrhoeal disease hospital in Bangladesh

The hospital records of 62 patients with blood culture-proven enteric fever admitted to the Dacca Hospital of the International Centre for Diarrhoeal Disease Research, Bangladesh, over a one-year period were reviewed. Older children and young adults had the highest age-specific rates of disease. The clinical, epidemiological and laboratory features of patients with enteric fever were compared with similar information from patients in hospital for cholera and shigellosis. Patients with enteric fever had a significantly longer prodrome of illness and were more likely to have fever than patients in the other groups. Our hospital cares primarily for patients with diarrhoeal diseases and while 94% of enteric fever patients had diarrhoea, only 5% had the recognized diarrhoeal pathogens Shigella or Vibrio cholerae identified, compared to 25% of the total hospital in-patient group, suggesting that Salmonella typhi itself may be a cause of diarrhoea. Antibiotic resistance patterns of S. typhi isolates were reviewed, and one isolate was found to be multiply antibiotic resistant. The advent of an effective oral typhoid vaccine makes further work on the epidemiology of enteric fever in endemic areas such as Bangladesh a high priority.

Surveillance of patients attending a diarrhoeal disease hospital in Bangladesh

In October 1979 a surveillance system was set up at the International Centre for Diarrhoeal Disease Research, Bangladesh, Hospital at Dacca to study a 4% systematic sample of the 100 000 patients with diarrhoea who come to the hospital for care each year. From December 1979 to November 1980 inclusive, 3550 patients were studied. A recognised pathogenic organism was identified for 66% of patients screened for all pathogens, one-third of whom had a mixed infection with two or more agents. Enterotoxigenic Escherichia coli was the most common enteropathogen detected in all age groups (detection rate 20%), followed by rotavirus (19%), Campylobacter jejuni (14%), and Shigella (12%). Infants and young children (up to 5 years) were most often infected with rotavirus, enterotoxigenic E coli, and C jejuni and older children (5-14 years) had more infections with enterotoxigenic E coli, Shigella, and E histolytica. Surveillance has helped to define the range of disease among patients attending the Dacca Hospital. Sixty-five per cent of patients complained of watery diarrhoea, a presentation that was significantly more common in patients with Vibrio cholerae 0:1 (91%), enterotoxigenic E coli (78%), rotavirus (77%), and C jejuni (71%) than in all patients studied. Dysentery, defined as a history of diarrhoea with blood, was the presenting complaint of 20% of all patients but 55% of those with Shigella. Only patients with V cholerae 0:1 and enterotoxigenic E coli were at increased risk for severe dehydration. In addition surveillance has been used to identify areas where patient care can be improved and to generate new ideas for research.

Epidemiologic and clinical features of patients infected with Shigella who attended a diarrheal disease hospital in Bangladesh

The epidemiologic and clinical characteristics of 412 patients infected with Shigella from a systematic sample of approximately 100,000 patients attending Dacca Hospital, International Centre for Diarrhoeal Disease Research, Bangladesh, between December 1, 1979, and November 30, 1980, were reviewed. Shigella was isolated from 11.6% of the 3,550 patients in the sample and was the second most common isolate in patients over two years old. Two clinical presentations of shigellosis were found: (I) watery diarrhea occurring in younger children and associated with a shorter duration of illness and with more vomiting and dehydration and (2) dysentery with stool blood and abdominal pain. These different presentations may reflect two mechanisms in the pathogenesis of shigellosis or different stages of the disease. The most useful signs and symptoms for the diagnosis of shigellosis were stool with blood and abdominal pain in all patients and the absence of watery diarrhea and vomiting in patients over one year old. Simple visual inspection of stool for blood correctly identified 44% of all patients infected with Shigella.