M. Mujibur Rahaman

PLASMID-MEDIATED RESISTANCE TO NALIDIXIC ACID IN SHIGELLA DYSENTERIAE TYPE 1

In an epidemic of shigellosis in southern Bangladesh the causal organism, Shigella dysenteriae type 1, was resistant to nalidixic acid as well as to co-trimoxazole (trimethoprimsulphamethoxazole) and ampicillin. The genes coding for resistance to nalidixic acid, but not those coding for resistance to co-trimoxazole or ampicillin, are located on a conjugative 20 megadalton plasmid. This epidemic is of particular importance because of the resistance to nalidixic acid, an antibiotic to which shigellae are seldom resistant, and because plasmids were previously thought not to mediate resistance to nalidixic acid.

DIARRHŒAL MORTALITY IN TWO BANGLADESHI VILLAGES WITH AND WITHOUT COMMUNITY-BASED ORAL REHYDRATION THERAPY

To combat dehydration from diarrhoea in Shamlapur, a village of 7021 people, multiple community-based points were set up by trained volunteers for the distribution of glucose-electrolyte oral rehydration salt (ORS) packets. The comparable adjoining village, Bordil, with a population of 3888, obtained its supply of ORS from Shamlapur. Surveilance for 2 years showed that although diarrhoeal attack-rates were equal, consumption of ORS after diarrhoea was 80% in Shamlapur and 38% in Bordil. There were 8 deaths in Shamlapur caused by diarrhoea and 23 in Bordil, showing an overall case fatality-rate of 0.5% and 2.4%, respectively, and a diarrhoeal mortality-rate per 1000 population of 0.6 and 2.9, respectively. The observation indicated that although it may not be possible to reduce diarrhoeal attack-rates, easy availability of rehydration solution and its early use after village-based training may save many lives, particularly those of children.

Impact of environmental sanitation and crowding on infant mortality in rural Bangladesh

In two villages of Bangladesh, 2471 infants born in 1976 and 1977 were followed up for a year to study the impact of environmental sanitation and crowding on their mortality. Neonatal and postneonatal mortality rates in the study cohort were 100 and 75 per 1000 live-births, respectively. Multiple logistic regression analysis was done to estimate the effects of the selected risk factors while controlling for some socioeconomic, demographic, and biological characteristics. Risk of postneonatal mortality (PNNM) in the households which did not use latrines was 3 X 12 times (p less than 0.01) higher than in those which did and 1.5 times (p less than 0.05) higher in the households with 10 or more persons than in smaller households. PNNM in the households which did not use tube-wells (hand-pump) water was higher, but not significantly so, than in those which used tube-well water for all purposes. Neonatal mortality was completely unrelated to the environmental factors investigated.

Hydrolysed wheat based oral rehydration solution for acute diarrhoea.

A randomised three cell study was carried out in 78 children with acute diarrhoea to evaluate the relative efficacy of oral rehydration solution (ORS) made from partially hydrolysed wheat grain, cooked rice powder, or glucose. Twenty six patients with comparable age, body weight, duration of diarrhoea, and degree of dehydration were studied in each of the three groups. Initial rehydration was carried out by using intravenous Dhaka solution within one to two hours followed by administration of oral rehydration solution. The mean ORS intake during the first and second 24 hours of treatment in patients with cholera receiving wheat-ORS and rice-ORS was significantly less compared with those receiving glucose-ORS. The stool output during the same period in patients receiving wheat-ORS and rice-ORS was significantly less compared with those receiving glucose-ORS. Similar trends in both ORS intake and stool output were observed during the next 24 hours.

Intake and absorption of nutrients in children with cholera and rotavirus infection during acute diarrhea and after recovery

The effect of diarrhea on nutrient intake was studied in 19 children with cholera and 13 with rotavirus. The co-efficients of absorption of fat, nitrogen and calories were calculated during the acute and the recovery stages of the disease. Compared to the recovery period, in the acute stage, the intake of nitrogen, fat and calories were reduced by 44%, 32% and 36% in cholera and 22%, 10% and 27% in rotavirus patients respectively. The co-efficient of absorption of nitrogen during the acute stages of both cholera and rotavirus was equally affected, being only 44 and 45% of the ingested amount respectively. In the acute stage, the rotavirus patients absorbed significantly less fat and calories than the cholera patients (44 and 55% in rotavirus versus 72 and 82% in cholera respectively). During the recovery period, the rotavirus patients absorbed a lesser amount of all the nutrients than the cholera patients, suggesting the presence of a longer period of malabsorption in rotavirus than in cholera.

Effects of Doxycycline in Actively Purging Cholera Patients: a Double-Blind Clinical Trial

In 51 actively purging cholera patients the efficacy of doxycycline, a long-acting tetracycline, was compared with a placebo and tetracycline hydrochloride. Seventeen patients who were given doxycycline at the recommended dose of 2 mg/kg at the beginning of the study, at 12 h, and at the repeated dose once daily purged a mean volume of 5.1 liters of stool and received an average of 5.7 liters of intravenous fluid. Nineteen patients receiving the placebo purged 10.1 liters of stool and received 9.7 liters of fluid. Fifteen patients given tetracycline hydrochloride at 6-h intervals passed 4.8 liters of stool and received 5.5 liters of fluid. The durations of diarrhea calculated in 8-h periods were 3.5, 8.0, and 4.1 h in the respective groups receiving doxycycline, placebo, and tetracycline. The differences between the doxycycline and placebo treatments and the tetracycline and placebo treatments were statistically significant. Those receiving doxycycline became vibrio-free in about 3 days as compared with 2 days for those receiving tetracycline; the group given the placebo were vibrio positive for the duration of their hospitalization. The results show that in the treatment of cholera the administration of doxycycline once daily has effects equal to those when tetracycline is administered at 6-h intervals. This is a distinct advantage because it decreases the demand on nursing personnel in epidemics. Also, doxycycline may be safely administered in cases of suspected renal failure from prolonged shock in cholera.

Birth care practice and neonatal tetanus in a rural area of Bangladesh.

Untrained personnel attend 2/3 of all births in the world. In many villages and urban areas of Asia; Africa and Latin America TBAs (traditional birth attendants) deliver majority of births. This paper reports the type of birth attendants; methods of cutting and dressing the umbilical cords and their relationship with the incidence of neonatal tetanus for a cohort of 1351 infants born between 7/76 to 6/77 in Teknaf area of rural Bangladesh. Most of the deliveries were conducted by untrained birth attendants and only <1% were delivered by trained midwives or physicians. 32% of the births were delivered by dais or TBAs; 35% by neighboring women; 30% by relations of the women and 3% were unattended. Razor blades were used to cut the umbilical cords in 22% and bamboo splits in 78%. Overall neonatal mortality rate due to tetanus was 27/100 live births. Among neonates whose umbilical cords were cut by razor blades mortality rate was 21/1000 live births compared to 29/1000 live births for those cut by bamboo splits. These rates were not considered statistically signficant. Mortality rate due to tetanus was significantly higher among the neonates whose umbilical cords were not tied with a thread than those tied with a thread. Incidence of neonatal tetanus can be lo considerably through improvement of rural sanitation and delivery techniques in home. Tetanus toxoid immunization of mothers was suggested as an effective remedy for the prevention of neonatal tetanus.

Infant Mortality in Rural Bangladesh: An Analysis of Causes During Neonatal and Postneonatal Periods

Reports on a study undertaken in Chittagong district of Bangladesh to examine the causes and some of the factors contributing to neonatal and postneonatal mortality and to identify the population at highest risk. A cohort of 1351 infants born between July 1976 and June 1977 was longitudinally followed up for 1 year in the Teknaf Dysentery Project demographic surveillance system. Results of the survey show an overall infant mortality rate of 160/1000 live births. Neonatal and postneonatal components were 89 and 71/1000 births respectively. Major causes of neonatal and postneonatal death were: tetanus (21%); pneumonia (19%); prematurity (12%); malnutrition (8%); diarrheal diseases (7%); and fever (6%). Tetanus premaurity and congenital abnormalities were the commonest causes of neonatal death whereas pneumonia malnutrition diarrheal disease and fever were the most important causes during the postneonatal period. Complications in delivery were significantly correlated with increased risk of neonatal mortality. The age of the mother was also a determinant of neonatal and mortality. The age of the mother was also a determinant of neonatal and postneonatal viability with mothers under the age of 20 having the greatest risk of death of her newborn. The age range 25-29 years conferred the greatest protection on neonates and postneonates. When the age of the mother is controlled parity is positively related to neonatal postneonatal and infant mortality rate. Large family size also correlates positively with the mortality rate.

IMPACT OF SUPPLEMENTARY FOOD ON INTAKE OF BREAST MILK IN DIARRHOEA

The intake of breast milk during acute and early convalescent stages of diarrhoea (over a 7-day period) and a fortnight after discharge from hospital (late convalescent stage) was monitored in 33 breastfed children aged 8-24 months. 16 were exclusively breastfed and 17 were partially weaned at the time of admission. On admission, weaning food was introduced to the exclusively breastfed children, whose intake of breast milk in the acute stage made up slightly more than half the total calorie intake of 70 +/- 4 kcal/kg/day. Their total calorie intake increased to 91 +/- 5 and 103 +/- 5 kcal/kg/day in the early and late convalescent stages, respectively, but the proportion made up by breast milk dropped to about a quarter. The breast milk intake of the partially weaned children made up nearly half their total calorie intake of 72 +/- 5 kcal/kg/day, and about a fifth of their total calorie intake of 94 +/- 5 kcal/kg/day and 104 +/- 5 kcal/kg/day, respectively, during the early and late convalescent stage, respectively.

Evaluation of Teknaf Enteric Agar (TEA): A Modified MacConkey's Agar for the Isolation of Shigella dysenteriae Type 1 and Shigella flexneri

To develop a better and selective medium for the isolation of Shigella spp., MacConkeys Agar (MAC) was modified by adding potassium tellurite (K2TeO3) at a concentration of 1 microgram/ml. The formulation designated Teknaf Enteric Agar (TEA) was studied for the inhibitory effect of potassium tellurite on the growth of different enteric bacteria, and as a medium for isolating Shigella spp. from clinical stool samples (n = 3125). We observed that the growth of E. coli was effectively inhibited on TEA with no effect on the growth of S. dysenteriae type 1 and S. flexneri. A total of 2019 Shigellae were isolated through the combined use of TEA, MAC, and Salmonella-Shigella Agar (SS). On TEA, 1921 S. dysenteriae type 1 and S. flexneri were isolated as compared to 1765 from the combined use of MAC and SS. A total of 194 of S. dysenteriae type 1 and S. flexneri were exclusively isolated from TEA as compared to 38 which were only made from MAC and SS. We conclude that TEA significantly increased the overall isolation rate of Shigella spp. as compared to the combined use of MAC and SS (P < 0.0001), although it is not suitable for the isolation of S. sonnei.