How dengue vector Aedes albopictus (Diptera: Culicidae) survive during the dry season in Dhaka City, Bangladesh?

BACKGROUND & OBJECTIVES: In 2000, a dengue outbreak occurred in Bangladesh that included Dhaka City. Both dengue vectors, Aedes aegypti and Ae. albopictus are present in Bangladesh. Aedes aegypti mosquitoes mainly breed in and around houses and Ae. albopictus is an outside breeder. There are many old trees throughout Dhaka City in different parks, streets and the university campus which may have holes that can contribute as potential breeding habitat for the dengue vector. Therefore, a survey was conducted to investigate the presence of eggs of the dengue vector mosquitoes in treeholes during the dry season in February 2001 to know their contribution on dengue outbreaks. METHODS: All treeholes in 10 different localities (parks, streets and university campus) of Dhaka City were surveyed. All trees were examined for treeholes up to the height of approximately 3 m and sampled. Debris were collected and packed in poly bags and brought to the laboratory for detailed studies. These were then soaked with tap water to observe egg hatching. The soaked materials were kept up to 20 days covered by a fine mosquito net. After 2-3 days, the eggs started hatching and larvae were separated from the sample for rearing up to IV instar. RESULTS: A total of 245 treeholes were surveyed in 49 identified tree species and 18 unidentified trees. Altogether, 1365 Aedes larvae were found, of which 1096 were Aedes albopictus and 269 were other Aedes species. The largest number of larvae was observed in Delonix regia of Leguminosae family. The number of Aedes albopictus found in the treeholes have perfect positive correlation with the number of other Aedes species. Not a single egg of Aedes aegypti was found in this survey. INTERPRETATION & CONCLUSION: This information will inform public health workers as well as the national control programme to help to solve mosquito borne diseases specially that of dengue. This is critical in planning for vector control operations due to the diversity of dengue outbreak in the nature.

The Habitual Additional Sodium Intake among Hypertensive Patients Visiting a Tertiary Health-care Center, Indore, Madhya Pradesh.

BACKGROUND: Hypertension prevalence is related to dietary sodium chloride intake. People are consuming much more sodium than is physiologically necessary. The consumption of processed food in urban India has led to a prevalence of 24%-30% of hypertension. The people have a special liking of such type of foods. This study aimed at assessing consumption of sodium among the study subjects to compare habitual additional consumption of sodium among hypertensive and normotensive patients and to find its associate factors impacting hypertension. MATERIALS AND METHODS: The hospital based, cross-sectional study was conducted on patients attending the outpatient department of general medicine. The sample size was 520 patients. Habitual additional intake of each patient was assessed by a food frequency table. RESULTS: As the age advances, the proportion of hypertensive patients increases (P < 0.05). Among hypertensive patients, 38.65% were not doing exercise (P < 0.05). The body mass index >25 was found among 11.92% normotensives and among 25.38% hypertensives (P < 0.05). There were 23% of hypertensive patients who could not receive dietary advice (P < 0.05). Habitual additional sodium consumption is more among 15-25 years age group (P < 0.05). Habitual additional sodium intake mean for those who were taking a pinch of salt is higher (P < 0.05). Habitual additional sodium intake is found to be significantly impacted by younger age, diagnosis, and lack of dietary advice (P < 0.05, P < 0.05, and P < 0.05). CONCLUSION: Most of the age groups are consuming more than 2 g habitual additional sodium which is more than the World Health Organization-recommended maximum levels. The dietary advice was given to hypertensives that had a positive impact on habitual additional sodium intake.