Therapeutic efficacy of chloroquine against uncomplicated, Plasmodium falciparum malaria in south-western Saudi Arabia.

The results of annual random screening indicated that Plasmodium falciparum strains showing chloroquine (CQ) resistance in vitro became increasingly common in the Jazan region of south-western Saudi Arabia between 1986 and 1998 (chi(2) for trend = 50.027; P < 0.001). This worrying trend and the emergence of a micro-epidemic in 1997-1998 prompted an assessment of the therapeutic efficacy of CQ against uncomplicated, P. falciparum malaria in the area. The in-vivo testing of sensitivity to CQ was carried out in 291 clinically manifest, microscopically positive cases of P. falciparum malaria. Most of these patients (88%) were successfully treated with a single standard regimen of CQ therapy. The other 36 patients (12%) showed early treatment failure or a poor response to the CQ, although all of these were then successfully treated with a single standard dose of sulfadoxine-pyrimethamine (Fansidar), as a replacement therapy. Those unsuccessfully treated with CQ were generally younger (t = 2.625; P = 0.01) and tended to have higher body temperatures (t = -2.62; P = 0.012) and higher levels of parasitaemia at initial presentation (P > 0.000) than those who responded well to the drug. Although CQ remains a reasonably effective drug for the treatment of malaria in the Jazan region, and therefore will be kept as the first-line drug for the foreseeable future, failure of CQ efficacy must be carefully monitored in the area.

Immunoregulatory and proinflammatory cytokine production in visceral and cutaneous leishmaniasis.

Visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL) are the major parasitic diseases in which the immune system is implicated in pathogenesis. The in vitro production of interleukin (IL)-2, IL-4, IL-6, IL-8, tumor necrosis factor-alpha (TNF alpha), and granulocyte-macrophage colony-stimulating factor (GM-CSF), spontaneously and in response to stimulation of peripheral blood mononuclear cells with anti-CD3, phytohemagglutinin, and lipopolysaccharide, was investigated to determine their importance in VL and CL. Highly enhanced production of IL-4, IL-6, IL-8, and TNF alpha was seen in VL. However, enhanced production of IL-4 and TNF alpha but almost normal production of IL-6 and IL-8 was seen in CL. The highly increased IL-4 production was the most characteristic and common feature of both VL and CL. Of interest, highly deficient GM-CSF production may be implicated in abnormalities in synthesis of hematopoietic lineage of cells in these diseases.

Cutaneous myiasis caused by tumbu fly larvae, Cordylobia anthropophaga in southwestern Saudi Arabia.

Seven cases of human cutaneous myiasis caused by maggots of the tumbu fly, Cordylobia anthropophaga are reported from Asir region, southwestern Saudi Arabia. Boil-like swellings infested with individual fly larvae, varied from one to four and occurred in both unprotected and usually protected areas of the skin. Twenty five fly maggots were retrieved from separate furunculoid lesions on the body surface of a massive case of a 4-year old boy. The present observations confirm that this calliphorine species is not restricted to tropical Africa.

Visceral spreading depletion of thymus-dependent regions and amyloidosis in mice and hamsters infected intradermally with Leishmania isolated from Sudanese cutaneous leishmaniasis.

Eighteen outbred mice and 21 golden hamsters were each inoculated intradermally with 2 X 10(6) Leishmania amastigotes obtained from 1 case of Sudanese cutaneous leishmaniasis. The skin lesions, spleen, lymph nodes, liver and kidney were examined by light-, polarizing-, and electron microscope at 5, 9 and 18 weeks after inoculation. The aim of the investigations was to follow the development of the inflammatory reaction and the change of the morphology of the lymphoid organs during the infection. In all the mice and in the majority of the hamsters visceral leishmaniasis developed which was characterized by a "noncure" type of cellular reaction, a selective T-cell depletion in the lymph nodes and the spleen, and the development of a reactive, systemic amyloidosis. These findings point to the failure of the acquired resistance against Leishmania to develop. In some of the hamsters the response was of the "cure" type without the development of amyloidosis. At the site of the inoculation the lesions healed suggesting the positive role of necrosis and the elimination of the parasites through the ulcer in the healing process. Electron microscopy showed erythrophagocytosis in the spleen of the 2 mice examined presenting an experimental evidence of the destruction of the red blood cells, which is a common feature of human kala-azar.

Use of the in vitro microtechnique for the assessment of drug sensitivity of Plasmodium falciparum in Sennar, Sudan.

In 1978, studies on the chloroquine sensitivity of Plasmodium falciparum were carried out in the district of Sennar, Sudan. The results of the in vivo tests showed parasites resistant at the RI level only, but the mean clearance time of trophozoites from the blood was higher than for strains found in many other areas of tropical Africa. The in vitro tests, using the microtechnique, indicated a lower sensitivity to chloroquine in the local P. falciparum isolates than in those of most other African countries. However, similar results have been reported from Ethiopia. The chloroquine sensitivity of P. falciparum from Sennar is close to the critical level of resistance. The in vitro microtechnique was also used to test for the sensitivity to Dabequin, 4-aminobenzo-quinoline, and was generally found to be a suitable and reproducible method, with a greater potential than the standard macro method. At parasite densities of over 100 000 asexual parasites per microlitre of blood the effect of a given concentration of chloroquine was related to the parasite density owing to the selective uptake of the compound by the parasitized cells.

Epidemic of cutaneous leishmaniasis in Northern Sudan.

This paper describes the first epidemic of cutaneous leishmaniasis to be reported from the Sudan. The epidemic occurred in villages in an area extending for about 100 km along the banks of the Nile between Shendi and Atbara. The disease affected people of all ages and the skin lesions, which were nodular or nodulo-ulcerative, were usually multiple.

The multiplication stages of Trypanosoma (Herpetosoma) xeri in the liver of the Sudanese ground squirrel Xerus (Euxerus) erythropus.

Blood and organ smears from 24 of 98 ground squirrels (Xerus erythropus) from the Sudan were infected with a trypanosome resembling Trypanosoma (Herpetosoma) xeri. The developmental stages are described from the liver of one heavily infected ground squirrel. Multiplication was by binary fission and numerous triangular amastigotes, sphaeromastogotes and trypomastigotes were observed. A tentative development cycle in the final host is presented.

Immunodiffusion, counterimmunoelectrophoresis and immunofluorescence in diagnosis of Sudan mucosal leishmaniasis.

Sera from 16 patients suffering from oral, nasal, oro-nasal or laryngeal types of Sudan mucosal leishmaniasis were tested against leishmanial antigen by three immunodiagnostic methods. Reactive soluble antigen was prepared from sonicated promastigotes. When tested against undiluted sera, in all 16 cases it gave easily visible precipitin lines in agar gel in both immunodiffusion and counterimmunoelectrophoresis tests. In immunofluorescence tests, with promastigote slide antigen and using the indirect antibody technique, the sera were positive at serum dilutions ranging from 1:200 to 1:6,400. There was no correlation between fluorescent titer levels and the strength of precipitin reactions in the immunodiffusionand counterimmunoelectrophoresis tests. Sixteen normal sera gave negative results in all three tests.

Symptomatic giardiasis in Sudanese adults and its treatment with tinidazole.

The main symptoms of infection with Giardia intestinalis in 33 Sudanese adults were abdominal pain, flatulence and diarrhoea. Other symptoms were offensive stools, loss of weight, milk intolerance, mucoid stools, nausea and vomiting. Tinidazole given orally as 150 mg. twice daily dose for seven days or as a single 1,000 mg. dose, eradicated the infection in 32 out of the 33 patients. This parasitological cure was obtained in all 21 patients who received the seven day course and in 11 out of 12 patients who were given the single dose. All symptoms disappeared in 16 out of the 32 patients and in the remaining half improvement was marked particularly as regards the three main symptoms of the disease. The single dose gave no side effects but nausea, headache, skin rash and worsening of abdominal pain and diarrhoea occurred in some patients who received the seven day treatment course.

A new focus of onchoceriasis in the Sudan.

A new focus of onchocerciasis is reported from Upper Atbara River area in the Sudan. This river is a known seasonal breeding place of Simulium damnosum. The area was sparsely populated in the past but now, following agricultural development, is inhibited mainly by immigrants from Northern Nigeria and Chad. Clinically the common features are skin changes of the legs, thighs buttocks, arms and trunk. Other features are corneal opacities and small often deeply placed subcutaneous nodules. Choroido-retinal degeneration, genital elephantiasis and hydrocoele, commonly associated with onchocerciasis in other parts of the Sudan, are absent.

Sudan mucosal leishmaniasis.

New cases of mucosal leishmaniasis and the first case of espundia-like muco-cutaneous leishmaniasis are reported from the Sudan. Cases previously reported are reviewed and the geographical distribution, clinical features, pathology, immunology and treatment of the disease are described. The majority of cases came from the known kala azar endemic regions of the central Sudan. The disease was seen in adult males, it commonly affected the mouth and nose causing in some cases permanent damage to teeth and nasal septi. In the lesions, the cellular infiltrate was composed mainly of histiocytes, lymphocytes and plasma cells. The number of parasites present was inversely related to the number of lymphocytes but was not related to the number of plasma cells. The level of the increased serum immunoglobulins was not constantly correlated with the number of any particular cell in the infiltrate. Treatment with sodium stibogluconate (Pentostam) was effective in the majority of cases.