C. B. Worth

Bio: C. B. Worth is an academic researcher. The author has contributed to research in topics: Portuguese East Africa. The author has an hindex of 1, co-authored 1 publications receiving 20 citations.

Culicine mosquitoes (Diptera: Culicidae) recorded from the province of Mozambique (Portuguese East Africa) and their relationship to arthropod-borne viruses.

Abstract: Edwards ( 1941) listed 22 species of culicine mosquitoes from the Province of Mocambique (Portuguese East Africa), deriving these records from the scanty literature and study of the few small collec+ tions available up to that time (Sant’ Anna, 1905; Seguy, 1959). In the same year de Meillon and Rebel0 ( 194 1) published additional records obtained incidentally during an anopheline survey of the country. This paper added 20 species to Edwards’ list, bringing the known fauna to 42. Pereira (1946a, 1946b) during further work with anophelines

Screening Mosquito House Entry Points as a Potential Method for Integrated Control of Endophagic Filariasis, Arbovirus and Malaria Vectors

Abstract: BACKGROUND Partial mosquito-proofing of houses with screens and ceilings has the potential to reduce indoor densities of malaria mosquitoes. We wish to measure whether it will also reduce indoor densities of vectors of neglected tropical diseases. METHODOLOGY The main house entry points preferred by anopheline and culicine vectors were determined through controlled experiments using specially designed experimental huts and village houses in Lupiro village, southern Tanzania. The benefit of screening different entry points (eaves, windows and doors) using PVC-coated fibre glass netting material in terms of reduced indoor densities of mosquitoes was evaluated compared to the control. FINDINGS 23,027 mosquitoes were caught with CDC light traps; 77.9% (17,929) were Anopheles gambiae sensu lato, of which 66.2% were An. arabiensis and 33.8% An. gambiae sensu stricto. The remainder comprised 0.2% (50) An. funestus, 10.2% (2359) Culex spp. and 11.6% (2664) Mansonia spp. Screening eaves reduced densities of Anopheles gambiae s. l. (Relative ratio (RR) = 0.91; 95% CI = 0.84, 0.98; P = 0.01); Mansonia africana (RR = 0.43; 95% CI = 0.26, 0.76; P<0.001) and Mansonia uniformis (RR = 0.37; 95% CI = 0.25, 0.56; P<0.001) but not Culex quinquefasciatus, Cx. univittatus or Cx. theileri. Numbers of these species were reduced by screening windows and doors but this was not significant. SIGNIFICANCE This study confirms that across Africa, screening eaves protects households against important mosquito vectors of filariasis, Rift Valley Fever and O'Nyong nyong as well as malaria. While full house screening is required to exclude Culex species mosquitoes, screening of eaves alone or fitting ceilings has considerable potential for integrated control of other vectors of filariasis, arbovirus and malaria.

The subgenus Stegomyia of Aedes in the Afrotropical Region with keys to the species (Diptera: Culicidae)

Abstract: The subgenus Stegomyia Theobald of the genus Aedes Meigen in the Afrotropical Region is characterized. Eleven species groups are recognized and diagnosed. The taxonomy, distribution, bionomics and medical importance of the species of the region are discussed and summarized. Keys and illustrations are provided for the identification of the 11 species groups and 59 species and subspecies known to occur in this region. Information on the present status of the species of the African Stegomyia is summarized. Six new species: Aedes ealaensis, ethiopiensis, gandaensis, hogsbackensis, mpusiensis and sampi are recognized. Aedes blacklocki Evans is restored to specific status. One subspecies, denderensis Wolfs is elevated to specific status.

Arbovirus prevalence in mosquitoes, Kenya

Abstract: Few studies have investigated the many mosquito species that harbor arboviruses in Kenya. During the 2006-2007 Rift Valley fever outbreak in North Eastern Province, Kenya, exophilic mosquitoes were collected from homesteads within 2 affected areas: Gumarey (rural) and Sogan-Godud (urban). Mosquitoes (n = 920) were pooled by trap location and tested for Rift Valley fever virus and West Nile virus. The most common mosquitoes trapped belonged to the genus Culex (75%). Of 105 mosquito pools tested, 22% were positive for Rift Valley fever virus, 18% were positive for West Nile virus, and 3% were positive for both. Estimated mosquito minimum infection rates did not differ between locations. Our data demonstrate the local abundance of mosquitoes that could propagate arboviral infections in Kenya and the high prevalence of vector arbovirus positivity during a Rift Valley fever outbreak.

Distribution and breeding sites of Aedes aegypti and Aedes albopictus in 32 urban/peri-urban districts of Mozambique: implication for assessing the risk of arbovirus outbreaks

Abstract: Background Aedes-borne arboviruses have emerged as an important public health problem worldwide and, in Mozambique, the number of cases and its geographical spread have been growing. However, information on the occurrence, distribution and ecology of Aedes aegypti and Ae. albopictus mosquitoes remain poorly known in the country. Methods Between March and April 2016, a cross-sectional study was conducted in 32 districts in Mozambique to determine the distribution and breeding sites of Ae. aegypti and Ae. albopictus. Larvae and pupae were collected from a total of 2,807 water-holding containers using pipette, dipper, funnel and sweeping procedures, depending on the container type and location. Both outdoor and indoor water-holding containers were inspected. The immature forms were reared to adults and the identifications of the mosquito species was carried out with a stereomicroscope using a taxonomic key. Results Aedes aegypti was found in every district sampled, while Ae. albopictus was only found in Moatize district, situated in Tete Province in the central part of the country. Six hundred and twenty-eight of 2,807 (22.4%) containers were positive for Ae. aegypti but only one (0.03%) was positive for Ae. albopictus. The Container Index (CI) of Aedes was highest in densely populated suburban areas of the central region (260/604; 43.0%), followed by suburban areas in northern areas (228/617; 36.9%) whilst the lowest proportion was found in urbanized southern areas (140/1586; 8.8%). The highest CI of Aedes was found in used tires (448/1268; 35.3%), cement tanks (20/62; 32.3%) and drums (21/95; 22.1%). Conclusion Data from our study showed that Ae. aegypti is present nation-wide, since it occurred in every sampled district, whilst Ae. albopictus had a limited distribution. Therefore, the risk of transmission of dengue and chikungunya is likely to have been underestimated in Mozambique. This study highlights the need for the establishment of a national entomological surveillance program for Aedes spp. in Mozambique in order to gain a better understanding about vector bionomics and to support the development of informed effective vector control strategies.

Isolation of Semliki Forest virus from Aedes (Aedimorphus) argenteopunctatus (Theobald) collected in Portuguese East Africa.

Abstract: 1. 1) A virus was isolated in mice from Aedes (Aedimorphus) argenteopunctatus (Theo.) collected at Namacurra, a town near the coast in Portuguese East Africa. 2. 2) Immunological studies with the haemagglutination-inhibition, complement-fixation and neutralization tests showed this virus, within the limits of the tests, to be immunologically identical with Semliki Forest virus. 3. 3) The previously demonstrated close immunological relationship among Semliki Forest, Mayaro and chikungunya viruses was confirmed. 4. 4) Results are presented of neutralization and haemagglutination-inhibition tests with three Group A viruses against selected sera from residents of northern Natal, Union of South Africa and Portuguese East Africa.