HIV/AIDS: the first 25 years--a view from Nairobi.

HIV infections are zoonoses occurring in communities that hunt chimpanzees (HIV 1) and sooty mangabeys (HIV 2) in the forests of equatorial and West Africa respectively. Most cross species transmission to man probably fizzles out, but the transmission of HIV 1 type M around 1930 eventually resulted in a pandemic that has spread around the world. HIV 2 types A and B have caused epidemics in West Africa. HIV infections are characterised by three phases (i) an initial, primary infective phase with rising viraemia, asymptomatic and silent, lasting for some 10 weeks, (ii) a long quiescent phase with the viraemia and illness mostly held in check by the immune response and lasting some 10 years in HIV 1 and 20 years or so in HIV 2 and (iii) a terminal third phase lasting some 10 months with rising viraemia, falling CD4 levels and multiple opportunistic infections recognised in a community by the onset of a florid AIDS epidemic. The silent primary epidemic reached Nairobi around 1980, with the florid secondary AIDS epidemic peaking here around 1992 and overwhelming the hospitals and other health services. The introduction of highly active antiretroviral therapy (HAART) has dramatically improved the prognosis for individual patients with AIDS, but it has been education and a changing attitude to condoms that has led to a progressive fall in incidence, so that the worst of the epidemic may now be over. Modifying the immunological response during the quiescent phase with the hope of prolonging this phase indefinitely may be the way forward for those who are already infected. Steroids have been shown to have a possible role here rather than anti-retroviral drugs (ARVs) which are not curative and prone to the development of drug resistance. Limited personal experience suggests that steroids may also have a role in salvaging critically ill AIDS patients, who need to be treated as emergencies. With an educated public and attention to alternative routes of infection such as blood transfusion, the epidemic should be increasingly contained during the next 25 years, and may even fizzle out.

The response of Kenyan kala-azar to treatment with sodium stibogluconate.

Of 16 patients with kala-azar treated with sodium stibogluconate (0.1 ml/kg body weight a day), one died on the 12th day of treatment and nine were cured by a 30-day course, although two subsequently relapsed. Extending the course cured a further five patients, and in one patient allopurinol was used in addition before a cure was achieved. Clinical and hematological recovery began within a few days of the start of treatment, but parasites continued to be seen in splenic aspirates for 3 weeks or more.

Allopurinol in the treatment of visceral leishmaniasis.

Allopurinol was used in the treatment of 10 patients with kala-azar. Of six patients who had previously failed to respond satisfactorily to Pentostam, "cures" were achieved in four. However, it was necessary to add Pentostam to the allopurinol in one, and another relapsed after apparent "cure" but again responded to allopurinol. The response of four patients who had had no previous treatment for kala-azar was less satisfactory.

Cutaneous leishmaniasis caused by Leishmania tropica in Kenya.

9 leishmanial strains, isolated from cutaneous papulonodular lesions on 3 patients, were characterized by cellulose acetate electrophoresis using 7 enzymes. The patterns obtained were indistinguishable from those of a Leishmania tropica reference strain and these 9 strains were similar to L. tropica in failing to infect mice. Although these 3 patients were Americans, their only potential exposure to sandflies was in Kenya, and thus they are believed to be the first cases of cutaneous leishmaniasis due to L. tropica in Kenya.

Chronic splenomegaly in Nairobi, Kenya. I. Epidemiology, malarial antibody and immunoglobulin levels.

Chronic splenomegaly in 131 Kenyan patients was investigated at Kenyatta National Hospital, Nairobi. Patients were allocated to diagnostic groups on the basis of clinical, haematological, parasitological, histological, radiological and endoscopic data. The major diagnostic groups were hyper-reactive malarial splenomegaly, our preferred name for tropical splenomegaly syndrome, (31%), hepatosplenic schistosomiasis (18%), visceral leishmaniasis (5%) and "indeterminate splenomegaly", where no diagnosis could be reached (12%). Another 20% of patients were suffering from various non-schistosomal forms of portal hypertension. A number of specific and rarer causes accounted for the rest of the cases. The tribal and geographical distribution of patients with chronic splenomegaly was compared with the pattern of general medical admissions. Splenomegaly was more frequent than expected in Kamba and Luo patients. Hyper-reactive malarial splenomegaly and hepatosplenic schistosomiasis were common in both groups, whereas visceral leishmaniasis was almost restricted to the Kamba and indeterminate splenomegaly was especially prevalent in the Luo. Malarial antibody and immunoglobulin levels differed significantly between the various diagnostic categories of patients and controls. Malarial serology can be diagnostically useful for chronic splenomegaly, provided results are interpreted in their geographical context.

Chronic splenomegaly in Nairobi, Kenya. II. Portal hypertension.

Eighty-five patients with chronic splenomegaly and proven oesophageal varices were studied at Kenyatta National Hospital, Nairobi. The major defined groups were hepatosplenic schistosomiasis (24%), cirrhosis (20%) and portal vein occlusion (11%). Hyper-reactive malarial splenomegaly (tropical splenomegaly syndrome) was considered as the cause of oesophageal varices in only one patient. In 26% of cases liver biopsy was non-diagnostic and the extrahepatic portal vein was demonstrated radiologically to be patent. Such patients were thought to be suffering from idiopathic portal hypertension, not previously described elsewhere in Africa. Hepatitis B surface antigen was detected in 12% of controls and in 58% of patients with cirrhosis (p less than 0.001). Some serological marker of previous hepatitis B virus infection was present in 92% of patients with cirrhosis and in 79% of controls. Kamba patients from Machakos and Kitui Districts were significantly more prevalent than expected among these 85 cases of portal hypertension.

Post kala-azar uveitis.

Three patients who developed bilateral anterior uveitis at the end of, or soon after, the apparently successful treatment of visceral leishmaniasis are described. The uveitis gave rise to secondary glaucoma in 2 of the patients, and in the third patient the eye lesions were associated with an episode of post kala-azar dermal leishmaniasis.

Below knee cast stresses and intra-cast pressures during normal walking.

Twenty-one tests on 13 volunteer subjects were used to quantify cast stresses and intra-cast pressures in below knee casts during normal walking. A microcomputer and force plate system were used to study the gait with various cast configurations. It was found that stresses were high where expected but also in less obvious locations, i.e. anterior and posterior aspects of the upper part of the cast. The data suggest that, irrespective of the design of the cast (as long as it is well fitting), control of rotation will be sufficient. This also validates the use of an articulating ankle component in most situations, although this type of cast provides less rotation control. If a fixed ankle is used then the casting material should be concentrated around the junction of foot and shank cylinders and less on the shank (only sufficient to provide rigidity). Comparison of different materials indicates that use of modern casting materials requires more emphasis on splint construction details than when using conventional plaster of Paris.

A simulation of the transmission of HIV and AIDS in regional populations within the United Kingdom.

"The spread of HIV-1 in the United Kingdom is simulated by a model which integrates behavioural and epidemiological processes within a multi-regional population projection framework and represents the spatial heterogeneities in the distribution of HIV which have significant effects on transmission patterns. Analyses determine the significance of different parameters in contributing to prediction uncertainty and highlight the importance of behavioural change and international population movements."

Resources for research: the 1991 census of population.

The author discusses population censuses in general and describes their utility for research, with a focus on the arrangements under which researchers at institutes of higher education are being provided with data sets from the census. "Although much of the discussion will be specific to the United Kingdom, many of the issues raised will be important in other countries."

Research policy and review 30. How to add value to migration data from the 1991 census.

"The form in which migration information is likely to be provided from the 1991 Census [of the United Kingdom] is reviewed, and suggestions are made about how this provision can be improved for the academic research community, building on the experience of the 1981 Census. The recommendations add considerable value to the information at relatively low cost."

What do you want from the 2001 census? Results of an ESRC/JISC survey of user views.

"The author describes the results of a survey of user views about the next Census of Population in the United Kingdom, to be held in 2001. Some 140 respondents reported their views, which included strong support for a question on income, endorsement of the new one number census methodology and support for postcode-based outputs. The author sets these views in the context of the Census Development Programme being carried out by the U.K. Census Offices and the proposals for outputs which are being discussed with the main census user sectors of central and local government, business, the Health Service, and the academic community."

Census-based information systems for ethnic groups: a study of Leeds and Bradford.

"In this paper are explored the problems involved in using Census data as a guide to the evolving ethnic geography of British cities. The relationship between the concept of ethnicity and Census questions on place of birth is traced. The country-of-birth statistics for Small Areas from the 1971 and 1981 Censuses are employed in an attempt to ascertain the influence of technical specifications on the measurement of the residential segregation of ethnic groups in order to distinguish real differences from apparent ones. The attempt is not fully successful, but it does provide clear pointers on how to proceed further in research on the ethnic spatial mosaics that [British] cities now are."

Assessment of some shock absorbing insoles.

Due to the increase in prescription of insoles to relieve symptoms due to skeletal shocks at heel strike a pilot study was initiated to look at some materials used for this purpose. Five materials were examined (Plastazote, Spenco, Sorbothane, Poron (PPT) and Viscolas) by two methods. The first method used an accelerometer mounted between the teeth of one of the authors (PR) to record skeletal shock. The second method used a force plate to record the shock produced by dropping a ball-bearing onto the insoles from a standard height. The results showed that Plastazote is poor at absorbing shock with Spenco and Sorbothane being quite good. The best insole materials tested were Poron (PPT) and Viscolas with the latter being marginally superior. No account was taken of degradation of the materials in use except that Plastazote worn for 72 hours was also used in the study, this producing the worst results.

The estimation of population microdata by using data from small area statistics and samples of anonymised records.

"Traditionally, estimates of the number of people in small areas (the smallest geographical units for which data are available) have been disaggregated only by age and sex. More recently, much research effort has been directed towards developing some form of enhanced small-area population estimation, in which the population in a small area is disaggregated not only by age and sex, but also by a wide range of additional economic and social characteristics. Solutions to this problem currently include account-based demographic models, often used by local authorities."

RTV silicone insoles.

A cheap and fast method of providing long term accommodating insoles is described. Room temperature vulcanizing (RTV) silicone rubber is used, with suitable coverings, to provide pain relief and support for feet and ankles. The combination of physical properties of the finished item provides a useful balance between support and flexibility which results in these insoles being readily accepted by the patients.