Long-term sampling of gamma sterilised male Glossina austeni (Diptera: Glossinidae) with sticky panels on Unguja Island (Zanzibar).

Daily catches of gamma sterilised male Glossina austeni Newstead with experimental sticky panels were analysed from March 1996 to July 1997. The flies were released weekly by light aircraft over primary and secondary forest ecosystems of Unguja Island, Zanzibar. In the primary forest, the cross-shaped royal blue XT panel (two interlocking panels of each 70 x 60 cm) trapped significantly more flies than the royal blue-white leg panel (panel with a body of 65 x 30 cm and two legs of each 15 x 15 cm) in all months, except in July 1996 and July 1997. In the same habitat, the cross-shaped royal blue-white leg panel (two interlocking leg panels) trapped from 1.7 (not significant) to 3.0 times (highly significant) as many flies as the standard leg panel depending on the season. Significantly more flies were trapped with the cross-shaped XT panel than with the leg panel in the secondary forest compared to the primary forest. Catches of the cross-shaped XT panel on each of a series of days, correlated well with those of the leg panel on the same day, except for panels deployed in the primary forest during the hot-dry and the beginning of the cold-dry season. Catches of the cross-shaped leg panel correlated less well with the catches of the standard leg panel in the primary forest. The data presented indicate that the behavioural responses in time and space of sterile male G. austeni are influenced by the type of trapping device used.

Responses of Glossina austeni to sticky panels and odours.

The responses of male tsetse Glossina austeni Newstead (Diptera: Glossinidae) towards blue and white sticky legged panels, baited with odour attractants, and towards modified panels were studied in the Jozani forest of Unguja Island, Zanzibar. Increasing the height of the body of a standard panel from 30 to 60 or 90 cm, increased the catch two-fold. Increasing the height of the legs (from 15 to 60 or 120 cm) or raising the device more than 5 cm above the ground reduced the catch significantly. The legs of the panels were the preferred landing sites of the flies, irrespective of the height of the body of the panel. Acetone (300 mg/h) combined with cow urine (60-130 mg/h) significantly increased the catches two- to threefold during the rainy season, but not during the dry season. Acetone had no effect during the dry season and its effect during the rainy season was less consistent. There was no effect of octenol (2.5-12.5 mg/h), used alone or in combination with acetone. Likewise, the catch did not increase through the addition of cow sebum, pig urine (60-860 mg/h), pig urine combined with acetone and octenol. The observed seasonal differences in the response of G. austeni towards odours are discussed in relation to host location strategies.

Glossina austeni (Diptera: Glossinidae) eradicated on the island of Unguja, Zanzibar, using the sterile insect technique.

An area-wide integrated tsetse eradication project was initiated in Zanzibar in 1994 by the International Atomic Energy Agency and the governments of Tanzania and Zanzibar, to eradicate Glossina austeni Newstead from Unguja Island (Zanzibar) using the sterile insect technique. Suppression of the tsetse population on Unguja was initiated in 1988 by applying residual pyrethroids as a pour-on formulation to livestock and by the deployment of insecticide impregnated screens in some of the forested areas. This was followed by sequential releases of gamma-sterilized male flies by light aircraft. The flies, packaged in carton release containers, were dispersed twice a week along specific flight lines separated by a distance of 1-2 km. More than 8.5 million sterile male flies were released by air from August 1994 to December 1997. A sterile to indigenous male ratio of >50:1 was obtained in mid-1995 and it increased to >100:1 by the end of 1995. As a consequence the proportion of sampled young females (1-2 ovulations), with an egg in utero in embryonic arrest or an uterus empty as a result of expulsion of a dead embryo, increased from <25% in the 1st quarter to >70% in the last quarter of 1995. In addition, the age structure of the female population became significantly distorted in favor of old flies (> or = 4 ovulations) by the end of 1995. The apparent density of the indigenous fly population declined rapidly in the last quarter of 1995, followed by a population crash in the beginning of 1996. The last trapped indigenous male and female flies were found in weeks 32 and 36, 1996, respectively. Time for 6 fly generations elapsed between the last catch of an indigenous fly and the end of the sterile male releases in December 1997.

Field responses of Glossina austeni to sticky panels on Unguja Island, Zanzibar.

Two designs of cross-shaped sticky panels (XT and XLP) were compared with the royal blue-white legpanel (LPBuWh) in the Jozani forest on Unguja Island as trapping devices for male Glossina austeni. Single coloured royal blue (XTBu) and bi-coloured royal blue-white XT (XTBuWh) caught more than twice as many male G. austeni as the LPBuWh, whereas single coloured black XT trapped significantly fewer flies (10%) than the control LPBuWh. XT's in various horizontal and diagonal blue-white configurations likewise trapped more flies than the LPBuWh, except a horizontally striped blue-white XT which trapped fivefold fewer flies than the LPBuWh. Cross-shaped LP in the blue-white (XLPBuWh) and black-white (XLPB1Wh) combination scored significantly better than the control LPBuWh. Similar fly numbers were trapped with XTBuWh and XLPBuWh. Long-term trapping data indicated that the XTBu, XTBuWh and XLPBuWh were three- to fourfold more effective in trapping female flies than the LPBuWh. The landing bias on bi-coloured panels was low in the blue-white but more pronounced in the blue-black and white-black combinations and was affected by the type of sticky panel used. A high proportion (49%) of the flies alighted on the bottom corners of the XTBu panel, but landing positions were more scattered if white was added. Increasing the width of the XTBu from 70 to 120 cm improved the catch by a factor of two as compared with standard sized XTBu. The effect of doubling the height of the XT on total fly catch was negligible. At present, it is the XTBu which can be recommended as the best trapping device for male and female G. austeni.

Schistosomiasis and bladder carcinoma in southern Iraq.

Bladder biopsies from 425 patients in the southern region of Iraq were analysed with special emphasis on the association of schistosomiasis and carcinoma. Histological evidence of schistosomiasis was seen in 27.3% of the carcinomas, 70.1% of which were of squamous-cell type. The main features were compared with those from other countries where Bilharziasis is endemic. It is concluded that the main features resemble previous reports but with a younger age incidence and relative high proportion of carcinomas in females affected by schistosomiasis.

Extraurinary schistosomiasis in Southern Iraq.

Ninety-six cases of extraurinary schistosomiasis due to Schistosoma haematobium were encountered in a retrospective histopathological study of cases encountered over a period of 12 years in Southern Iraq. Seventy-six cases involved three main systems, namely the female genital system (29 cases), male genital system (15 cases) and the lower intestinal tract (32 cases). In the remaining 20 cases unusual sites such as lymph nodes, skin, liver and lungs were affected. In none of these cases did the clinician initially consider schistosomiasis to be the cause of the patient's illness prior to the histological diagnosis.

Scanning electron microscopy.

The technology of scanning electron microscopy (SEM) is described in brief. Its application to the study of cell and tissue structure is demonstrated and the evolution of the concept of "topographical histology" is discussed. Some current literature on the application of SEM is reviewed under the headings of experimental pathology and human pathology. While SEM has become an indispensable technique for the experimental morphologist, its application to diagnostic pathology and cytology is still at an early exploratory stage.