Biting patterns and seasonality of Anopheles gambiae sensu lato and Anopheles funestus mosquitoes in Kamuli District, Uganda.

BACKGROUND: We investigated the biting patterns and seasonal abundances of Anopheles gambiae s.l. and An. funestus mosquitoes in Kamuli District, Uganda. METHODS: Hourly indoor and outdoor catches of human biting mosquitoes were sampled from 19.00 to 07.00 hours for four consecutive nights each month using bed net traps in forty-eight houses randomly selected from Bugabula county where insecticide-treated bed nets (ITNs) had been used for at least five years and Budiope county where ITNs had not been used. The indoor and outdoor human-biting fractions, time of biting of the anophelines and climatic data were recorded from January to December 2010. Data were analysed using Multi-way analysis of variance, Kruskal-wallis rank sum test and Pearson correlation. The number of mosquitoes caught biting humans and resting indoors, the indoor and outdoor human biting densities and biting rates during different hours of the night, and mosquito abundances for a twelve-month sampling period in both zones are reported. RESULTS: Approximately four times more Anopheles mosquitoes were caught biting humans in Budiope County than in the Bugabula zone, with An. gambiae s. l. catches exceeding those of An. funestus. In both zones, peak night biting occurred between 23.00 and 05.00 hours. The majority of bites occurred between 03.00 and 06.00 hours for both Anopheles gambiae s. l. and funestus group. Outdoor biting densities of Anopheles gambiae s. l. exceeded the indoor biting densities throughout the night in both zones, while the indoor and outdoor human biting densities of An. funestus group were apparently equal. The outdoor and indoor human biting rates were similar in both zones. In Bugabula county, the abundance of An. gambiae s.l. was rainfall-dependent, while the An. funestus group could thrive with or without rain fall. In Budiope county, both An. gambiae s.l. and An. funestus mosquitoes thrived all year round regardless of the amount of rainfall. CONCLUSION: Considering the biting patterns, and seasonal abundances exhibited by Anopheles gambiae s.l. and An. funestus mosquitoes in Kamuli district, intensive use of ITNs combined with indoor residual spraying, environmental management and improved house designs in the context of integrated vector management may be the appropriate vector control strategy.

Intestinal helminths in Luweero district, Uganda.

BACKGROUND: Intestinal helminthiasis is a debilitating parasitic disease found in many parts of Uganda including Luweero district. In the district, the disease causes as high as 9% morbidity in children below five years. There was very scanty district information on the disease based mainly on hospital records despite this figure. The current study was carried out to provide data to plan for its effective control. OBJECTIVE: To investigate risk factors that promote helminth infections among children under five years of age in Luweero district. METHODS: Stool samples from 727 children were examined for presence of helminth ova using Kato-Katz technique. The subjects' parents or guardians were interviewed using a semi-structured questionnaire to establish their demographic, social-cultural characteristics; information on water accessibility and usage; child toileting practices and knowledge about helminthiasis. RESULTS: Risk factors strongly associated with helminth infections included methods of anal cleaning, how compounds and latrines were maintained, keeping of pigs and age of the subjects, (P <0.001). In addition, methods of hand washing after latrine visits, the respondents' education level, type of house floor and household compound as well as accessibility to water were associated with worm infection. CONCLUSION: The hygiene practices of the parents/guardians and environmental surroundings in which the child grows play a big part in determining his or her helminth status. The District Health workers, community leaders and extension staff should educate the community on the importance of personal hygiene and environmental sanitation to minimize the risks of helminth infections.