Malaria-related anaemia.

Malaria infection in humans by Plasmodium species is associated with a reduction in haemoglobin levels, frequently leading to anaemia. Plasmodium falciparum causes the most severe and profound anaemia, with a significant risk of death. This cannot be explained simply by the direct destruction of parasitized red blood cells at the time of release of merozoites, a process shared by all these species. In this review, Clara Menendez, Alan Fleming and Pedro Alonso focus on recent advances in our knowledge of the pathophysiology, epidemiology, management and prevention of anaemia from falciparum malaria.

Pregnancy- and lactation-related folate deficiency in South Africa--a case for folate food fortification.

OBJECTIVE: Characterisation of patients presenting with megaloblastic anaemia according to clinical, sociological, haematological and aetiological aspects of their disease, and use of these findings to increase awareness among clinicians and to make recommendations regarding changes in national health policy. METHODS: This study included 104 patients presenting with megaloblastic anaemia to a large referral hospital over a 1-year period. Data were collected and analysed in terms of age, gender, parity, gravidity, duration of lactation, socio-economic status, geographical origins, diet, previous haematinic treatment, clinical presentation and haematological measurements. RESULTS: The most common cause of megaloblastic anaemia was pernicious anaemia or probable pernicious anaemia (50%), followed by pregnancy- and lactation-related folate deficiency (32%); of these patients, the majority (28) presented postpartum while lactating; 5 patients were in the immediate puerperal period of 6 weeks, and a further 16 were seen during the first year and 7 during the second year following delivery. Only 4 patients were pregnant, and it is noteworthy that 2 of these were still lactating at 34 weeks' gestation. CONCLUSION: Pregnancy- and lactation-related folate deficiency up to 2 years after delivery remains a common cause of megaloblastic anaemia in South Africa. Certain communities in rural South Africa have recently been shown to have high incidences of both neural tube defects and folate deficiency. The fortification of a staple food (e.g. maize or flour) with folic acid is feasible, inexpensive, safe and likely to be beneficial. This practice should reduce the prevalences of megaloblastic anaemia in fertile women, neural tube defects, other congenital abnormalities, intra-uterine growth retardation, prematurity and possibly cardiovascular disease. There is urgent need for a national policy in this regard.

'Improved sensitivity of direct microscopy for detection of acid-fast bacilli in sputum in developing countries.

Diagnosis of pulmonary tuberculosis depends on the bacteriological examination of sputum. Sputum smear microscopy is efficient and can confirm the disease. However, direct microscopy of sputum, though rapid, has low sensitivity. There is, therefore, an urgent need to develop rapid, much more sensitive and specific methods. In a field study we collected sputum samples from 488 tuberculosis suspects and compared the results of examining smears prepared after treatment with sodium hypochlorite (NaOCl) and concentration of bacteria by centrifugation and direct staining with Ziehl-Neelsen stain. Direct smears stained with auramine-phenol were the reference standard. The use of NaOCl increased the sensitivity from 43.4% to 76.3%, with a specificity of 100% for both methods. The method is simple and cheap. As a potent disinfectant, NaOCl also reduces the risk of laboratory-acquired infection. Its application would increase the efficiency of tuberculosis control programmes.

The value of the intrinsic factor antibody test in diagnosing pernicious anaemia.

OBJECTIVE: Assessment of the usefulness of the intrinsic factor antibody (IF Ab) test in comparison to the Schilling test in diagnosing pernicious anaemia (PA) in patients with vitamin B12 deficiency. DESIGN: This study was designed to compare the If Ab test to the Schilling test using results obtained of patients presenting with megaloblastic anaemia and low serum vitamin B12 levels to a large referral hospital. SETTING: The Chris Hani Baragwanath Hospital, Soweto, Gauteng, South Africa. SUBJECTS: Results from 77 patients with megaloblastic anaemia, low serum vitamin B12 levels and with both Schilling and IF Ab test results available were included. MAIN OUTCOME MEASURES: The sensitivity and specificity of the IF Ab test was compared to the Schilling test with regard to making a diagnosis of PA in patients presenting with megaloblastic anaemia and low serum vitamin B12 levels. RESULTS: Relevant statistical analysis showed that in the correct clinical setting, a confident diagnosis of PA could be made without Schilling tests in patients with megaloblastic anaemia, vitamin B12 deficiency and positive IF Ab tests. In a small proportion of patients in whom the IF Ab is negative, Schilling tests still need to be performed. CONCLUSION: With the increased concern over rising medical costs and where limited facilities are available, the IF Ab, in the correct clinical setting, is a cost effective and reliable test for diagnosis of PA.

HIV and blood transfusion in sub-Saharan Africa.

Blood transfusion services were poorly developed until the mid 1980s in most of sub-Saharan Africa, and were unable to provide adequate supplies of blood with acceptable safety. The pandemic of HIV was recognized seroepidemiologically from 1985 onwards. Blood transfusion was contributing from 10 to 15% to transmission in Africa. Groups at highest risk are children with malaria and anaemia, women with pregnancy-related haemorrhage or anaemia, victims of trauma and subjects with sickle-cell disease. Haemophiliacs are not a major risk group in comparison. Blood transfusion services have undoubtedly benefitted from the international, national and regional responses to the AIDS epidemic. Organizational structures have been established. There have been concerted moves to recruit voluntary unremunerated blood donors, selected from population groups with low seroprevalence. Serological screening for HIV, hepatitis viruses and syphilis has been introduced or strengthened. Standards for blood group serology, blood storage and handling have been improved. Guidelines for the appropriate use of blood have been formulated and adopted. There have been many training and retraining programmes. Much remains to be completed, however, using national and international resources, before the blood supply reaches acceptable standards of safety and is adequate in remote as well as in central areas of Africa.

PIP: Blood transfusion services for civilian populations were poorly established until the mid-1980s in most of sub-Saharan Africa and were unable to provide sufficient supplies of blood with acceptable safety. From 1985 onwards the HIV pandemic was recognized seroepidemiologically. About 10-15% of HIV transmission has been related to blood transfusion. The high-risk groups are children suffering from malaria and anemia, women with pregnancy-related hemorrhage or anemia, victims of trauma, and persons with sickle cell disease. However, hemophiliacs are not a major risk group in comparison. As a result of the HIV/AIDS pandemic, national and international attention has at last been focused on the inadequacies of blood transfusion services. Organizational structures have been developed. There have been concerted efforts to recruit voluntary unremunerated blood donors, chosen from population groups with low seroprevalence. Serological screening for HIV, hepatitis viruses, and syphilis has been introduced or strengthened. Standards for blood group serology, blood storage, and handling have been improved and guidelines for the proper use of blood have been developed and adopted. In addition, there have been many training and retraining programs. Much has yet to be completed, however, using national and international resources, before the blood supply achieves acceptable standards of safety and is adequate in both remote and central areas of Africa.

Clinical features of HIV seropositive Zambian subjects.

Data was collected from 1595 anti-HIV positive patients out of which 90% of the patients were from the Copperbelt province, and the rest from five out of the eight other provinces of Zambia. One-hundred and one positive HIV patients were less than 2 years of age, 69 were aged 2 to 14 years and 1418 were aged above 15 years. The male to female ratio was about 1:1 at all ages, except that there was an excess of males below 5 years. Of the four most frequent symptoms or signs, loss of weight or malnutrition was regarded in about 50% of seropositive patients at all ages; generalized lymphadenopathy was seen in at least 35% of all age groups and most frequently at 2-14 (60%); chronic watery diarrhoea was most common at less than 2 years (44%) and least common in older children (17%); chronic chest infections had highest frequency in children 2-14 years (59%) and lowest in adults (32%). Intensive education of children before they are sexually active is the best hope for controlling the epidemic.

PIP: During December 1985 to November 1986, in Zambia, clinicians provided information on 1595 HIV-positive patients to assess the age and sex distribution and clinical features of HIV-positive patients. 92.2% of the HIV-positive patients were from the Copper Province, especially the towns of Ndola (44.9%) and Kitwe (28.9%). 101 HIV-positive patients were under 2 years old, 69 were aged 2-14 years, and 1418 were 15 years old or older. The most common clinical features of HIV infection in all age groups were weight loss/malnutrition (about 50%) and generalized lymphadenopathy (35.1%). They were malnutrition (56.5%), chronic chest infection (48.2%), chronic diarrhea (43.5%), and generalized lymphadenopathy (43.5%) for children aged under 2; generalized lymphadenopathy (60.3%), chronic chest infection (58.6%), weight loss/malnutrition (55.2%), and chronic diarrhea (17.2%) for children aged 2-14; and weight loss (49.3%), generalized lymphadenopathy (33.4%), chronic chest infection (32.3%), chronic diarrhea (29.6%), herpes zoster (14.7%), and sexually transmitted diseases (10.6%) for people aged 15 and older. Generalized lymphadenopathy was significantly more common in the 2-14 year old group than the older age group (60.3% vs. 33.4%; p 0.05). People aged 15 and over were significantly less likely to have chronic chest infection than the other age groups (32.3% vs. 48.2-58.6%; p 0.05). The male/female ratio was 1:0.93 in the 15 and older age group. Solid education of school-aged children before they become sexually active provides the best hope for controlling the HIV/AIDS epidemic in Zambia.

Haemophilia in northern Nigeria.

Thirteen patients from 11 families were diagnosed as cases of haemophilia A or B during 1977 to 1984. The majority presented with post circumcisional bleeding. Cryoprecipitate and packed red cells were used in the management. Haemophilia and other inherited bleeding disorders are not as rare as otherwise assumed. This is the first report from Northern Nigeria.

Agriculture-related anaemias.

Man evolved as a hunter-gatherer, and the invention and spread of agriculture was followed by changes in diet, the environment and population densities which have resulted in globally high prevalences of anaemias due to nutritional deficiencies of iron, folate and (locally) vitamin B12, to infestations by hookworm and schistosomes, to malaria, and to the natural selection for the genes for sickle-cell diseases, beta-thalassaemias, alpha-thalassaemias, glucose-6-phosphate dehydrogenase deficiency, ovalocytosis and possibly (locally) elliptocytosis. The present explosion of population is driving an expansion of agriculture, especially the cultivation of rice, and this has led often to disastrous increases of transmission of malaria, schistosomiasis and other diseases, to widespread chemical pollution, and to degradation of the environment. Anaemia, as the commonest manifestation of human disease, is a frequent consequence. The urgent need for increased food production is matched by the urgent need for assessment and control of the health impact of agricultural development.

Residual risk of transmission of HIV through blood transfusion in South Africa.

Despite the ongoing review of donor recruitment criteria by local blood transfusion services and the development of highly sensitive and specific testing for the presence of antibodies to HIV in blood and blood products, there remains a residue of HIV in donated blood. This is because of donors who are in the 'window period' between acquisition of HIV and seroconversion, human errors and limits to the sensitivity and specificity of current tests. Data available from a national survey of HIV seroprevalence in South African blood donors allowed for the estimation of the number of units screened negative but likely to be infected with HIV. Assuming window periods of 4.8 and 14 weeks, a test sensitivity of 99.9%, a specificity of 98.5% and a human error rate of 0.1%, the likely rate of HIV-infected blood in the South African blood transfusion supply ranges from 1.1 to 3.9/100,000 units, with a likely estimate of 2.2/100,000 units. In the current South African blood transfusion setting, between 8.1 and 28.2 units of blood per annum will be HIV-positive with a likely estimate of 15.9 units. This corresponds to an odds ratio of between 1:90 909 and 1:25 641 units infected with HIV. These data are comparable with the risk in developed countries. The expected increase in the incidence and prevalence of HIV infection in all adult South African populations necessitates additional measures to ensure a blood supply which is as safe as possible. Some of these measures have already been taken by local blood transfusion services.

Glycophorin variants and Plasmodium falciparum: protective effect of the Dantu phenotype in vitro.

Experimental work was carried out to establish the growth characteristics of Plasmodium falciparum in an in vitro culture system using cells with the Dantu, Henshaw and S-s-U- blood-group variants. A flow cytometric technique, using the dye thiazole orange, was adapted for use on the Epics Profile II flow cytometer to count the parasites. This was performed at 24, 48 and 72 h. The ability of the parasites to grow in red cells of the Dantu and Henshaw phenotypes was also assayed by 3[H] hypoxanthine incorporation. Relative to control red cells, S-s-U- cells and Dantu cells were less suitable as host cells for P. falciparum in vitro. In contrast, cells expressing the Henshaw antigen were equally sensitive to P. falciparum infection as were normal controls. These data support the notion that glycophorins play an important role in P. falciparum infection. Further studies are required to evaluate the epidemiological significance of these results.