The best of both worlds: no apparent trade-off between immunity and reproduction in two group-living African mole-rat species.

Co-operatively breeding mammals often exhibit a female reproductive skew and suppression of the subordinate non-breeding group members. According to evolutionary theory and the immunity-fertility axis, an inverse relationship between reproductive investment and survival (through immunocompetence) is expected. As such, this study investigated if a trade-off between immunocompetence and reproduction arises in two co-operatively breeding African mole-rat species, namely the Damaraland mole-rat (Fukomys damarensis) and common mole-rat (Cryptomys hottentotus hottentotus), which possess female reproductive division of labour. This study also attempted to investigate the relationship between the immune and endocrine systems in Damaraland mole-rats. There was no trade-off between reproduction and immunocompetence in co-operatively breeding African mole-rat species, and in the case of the Damaraland mole-rats, breeding females (BFs) possessed increased immunocompetence compared with non-breeding females (NBFs). Furthermore, the increased levels of progesterone possessed by Damaraland mole-rat BFs compared with NBFs appear to be correlated to increased immunocompetence. In comparison, BF and NBF common mole-rats possess similar immunocompetence. The species-specific differences in the immunity-fertility axis may be due to variations in the strengths of reproductive suppression in each species. This article is part of the theme issue 'Evolutionary ecology of inequality'.

A position statement and practical guide to the use of particulate filtering facepiece respirators (N95, FFP2, or equivalent) for South African health workers exposed to respiratory pathogens including Mycobacterium tuberculosis and SARS-CoV-2.

SUMMARY: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is transmitted mainly by aerosol in particles <10 µm that can remain suspended for hours before being inhaled. Because particulate filtering facepiece respirators ('respirators'; e.g. N95 masks) are more effective than surgical masks against bio-aerosols, many international organisations now recommend that health workers (HWs) wear a respirator when caring for individuals who may have COVID-19. In South Africa (SA), however, surgical masks are still recommended for the routine care of individuals with possible or confirmed COVID-19, with respirators reserved for so-called aerosol-generating procedures. In contrast, SA guidelines do recommend respirators for routine care of individuals with possible or confirmed tuberculosis (TB), which is also transmitted via aerosol. In health facilities in SA, distinguishing between TB and COVID-19 is challenging without examination and investigation, both of which may expose HWs to potentially infectious individuals. Symptom-based triage has limited utility in defining risk. Indeed, significant proportions of individuals with COVID-19 and/or pulmonary TB may not have symptoms and/or test negative. The prevalence of undiagnosed respiratory disease is therefore likely significant in many general clinical areas (e.g. waiting areas). Moreover, a proportion of HWs are HIV-positive and are at increased risk of severe COVID-19 and death. RECOMMENDATIONS: Sustained improvements in infection prevention and control (IPC) require reorganisation of systems to prioritise HW and patient safety. While this will take time, it is unacceptable to leave HWs exposed until such changes are made. We propose that the SA health system adopts a target of 'zero harm', aiming to eliminate transmission of respiratory pathogens to all individuals in every healthcare setting. Accordingly, we recommend: the use of respirators by all staff (clinical and non-clinical) during activities that involve contact or sharing air in indoor spaces with individuals who: (i) have not yet been clinically evaluated; or (ii) are thought or known to have TB and/or COVID-19 or other potentially harmful respiratory infections;the use of respirators that meet national and international manufacturing standards;evaluation of all respirators, at the least, by qualitative fit testing; andthe use of respirators as part of a 'package of care' in line with international IPC recommendations. We recognise that this will be challenging, not least due to global and national shortages of personal protective equipment (PPE). SA national policy around respiratory protective equipment enables a robust framework for manufacture and quality control and has been supported by local manufacturers and the Department of Trade, Industry and Competition. Respirator manufacturers should explore adaptations to improve comfort and reduce barriers to communication. Structural changes are needed urgently to improve the safety of health facilities: persistent advocacy and research around potential systems change remain essential.

Long-COVID: An evolving problem with an extensive impact.

Persistence of symptoms or development of new symptoms relating to SARS-CoV-2 infection late in the course of COVID-19 is an increasingly recognised problem facing the globally infected population and its health systems. 'Long-COVID' or 'COVID long-haulers' generally describes those persons with COVID-19 who experience symptoms for >28 days after diagnosis, whether laboratory confirmed or clinical. Symptoms are as markedly heterogeneous as seen in acute COVID-19 and may be constant, fluctuate, or appear and be replaced by symptoms relating to other systems with varying frequency. Such multisystem involvement requires a holistic approach to management of long-COVID, and descriptions of cohorts from low- and middle-income countries are eagerly awaited. Although many persons with long-COVID will be managed in primary care, others will require greater input from rehabilitation medicine experts. For both eventualities, planning is urgently required to ensure that the South African public health service is ready and able to respond.

The reliability of the modified lower extremity functional scale among adults living with HIV on antiretroviral therapy, in Rwanda, Africa.

Peripheral neuropathy (PN) is common among people living with HIV (PLHIV) on antiretroviral therapy (ART), and affects their daily functional ability and quality of life. Lower extremity functional ability, which is most commonly compromised in patients with PN, has not been clearly evaluated in an African setting, with regard to functional limitations. The lower extremity functional scale (LEFS) was originally developed and validated among elderly people in the USA, where the environment and activities of daily life are very different from those in Rwanda. The purpose of this study was to adapt and establish the reliability of LEFS, among adults living with HIV on ART, in a Rwandan environment. The study translated LEFS from English to Kinyarwanda, the local language spoken in Rwanda, the LEFS was then modified accordingly, and tested for test-retest reliability among 50 adult PLHIV on ART. An average Spearman rank order correlation coefficient, ρ ≥ 0.7, was considered optimal for reliability. Prior to the modification of the LEFS and in the initial testing of the translated LEFS, none of the activities was strongly correlated (ρ ≥ 0.8); most of the activities (90%, 18/20) were moderately correlated (ρ ≥ 0.5) and 10% (2/20) were weakly correlated (ρ ≤ 0.5). The ρ of most of the functional activities improved after modification by an expert group to ρ ≥ 0.7, establishing reliability and validity of LEFS among PLHIV on ART with lower extremity functional limitations, in this environment. In conclusion, this study demonstrated the importance of modifying and establishing test - retest reliability of tools derived from developed world contexts to local conditions in developing countries, such as in Rwanda. The modified LEFS in this study can be used in Rwanda by clinicians, specifically at ART clinics to screen and identify people with functional limitations at an early stage of the limitations, for treatment, rehabilitation and/or referral to appropriate health care services.

Esophageal squamous metaplasia: nudging the esophageal carcinoma morphogenetic paradigm.

The concept regarding esophageal squamous metaplasia, its existence, origin and the role it plays in the etiology of esophageal carcinoma, needs some urgent attention. Explanations regarding the presence of metaplastic squamous epithelial cells on esophageal smears, from asymptomatic high-risk patients undergoing screening for esophageal carcinoma, are difficult to find. The presence of squamous metaplastic cells on smears from the esophagus collected by us since 1983, from rural Transkei populations, is a regular finding and warrants some discussion. Cellular material from the esophageal lumen is collected with a gelatine encapsulated sponge brush for cytological evaluation. Each full-length, 'blind' sampling procedure produces a mixture of single cells, sheets, small groups as well as microbiopsies. Some very well preserved and excellent examples of esophageal epithelium undergoing or in a state of squamous metaplasia are a regular find.

Oesophageal and other cancer patterns in four selected districts of the Transkei, Southern Africa:1985-1990.

New data regarding the incidence of oesophageal and other cancers during the period 1985-1990 are reported for all clinics and hospitals in four selected districts of Transkei, Southern Africa i.e. Kentani, Butterworth, Lusikisiki and Bisana. Active and passive methods were used to obtain the hospital-based cancer registry data. The mean annual number of cancer cases recorded for the period 1985-1990 was 292. Age-standardised incidence rates (ASIR, African standard) for all recorded cancer were 81.4 and 52.6/100,000 for males and females respectively. Histopathological examination of 52.6% of recorded tumors revealed that 67.3% were squamous carcinomas, 21.7% adenocarcinomas and the remainder non-epithelial neoplasm. Cancer of the oesophagus (OC) was the most frequently recorded cancer and accounted for the 46.5% of the cases with mean ASIR of 46.7 and 19.2/100,000 for males and females respectively. The male/female ratio was 2.4:1. The highest mean ASIR per annum for OC in males (55.6/100,000) occurred in Kentani and in females (22.3/100,000) in Lusikisiki, whereas the lowest rates in both sexes (37.0 and 11.7/100,000 respectively) occurred in Bizana. Comparison of the OC rates in the four districts of Transkei during 19985-1990 with previous reported trends, confirms a consistently high rate in the south-western districts of Kentani during the past 35 years and progressively increasing rates in the north-eastern districts of Bizana and Lusikisiki. These results have profound implications for further epidemiological and aetiological studies on OC in Transkei, but we need to be corroborated by data form other sources such as statistics on histologically diagnosed cancer in Transkei by districts in the South African National Cancer Registry. The second most frequent recorded cancer among males was liver cancer with a mean annual ASIR of 6.0/ 100,000 and male:female ratio of 3:1. The most frequent recorded cancer among females was cervical cancer with a mean annual ASIR of 20.9/100,000 followed by OC (19.2/100,000) and breast cancer (5.8/100,000).

Red kidney beans--to eat or not to eat?

The importation of dry red kidney beans (a variety of the species Phaseolus vulgaris) for cultivation or consumption in South Africa is prohibited because of their potential toxicity to humans. It has been established that the haemagglutinating lectins (e.g. phytohaemagglutinin (PHA)) in kidney beans are responsible for this toxicity. Dry bean varieties available on the South African market for human consumption as well as locally produced (for this study) and imported dry red kidney beans and imported canned red kidney beans were compared. The PHA activity and the effect of heat thereon were measured, before and after overnight soaking. The PHA activity in extracts of uncooked and incompletely cooked red kidney beans was not higher than the levels measured in 50% of the other bean varieties included in the study. These findings indicate that the toxic potentials and health risks associated with red kidney beans are similar to those of other dry beans already commercially available to South Africans.

Folic acid and vitamin B12 status of vervet monkeys used for nutritional research.

Plasma and red blood cell (RBC) folic acid levels, as well as plasma vitamin B12 levels were determined in Vervet monkeys (Cercopithecus aethiops). All the vervets were apparently healthy and without symptoms or lesions typical of folic acid and/or vitamin B12 deficiencies. Competitive protein binding radioassays were used to determine folate and vitamin B12 values in animals fed 4 different diets. The B12 levels for all the groups ranged between 866 and 5867 pg/ml and showed an inverse relationship with the FA measurements. The lowest mean RBC folic acid content in a group fed an atherogenic diet for 3 years was 12.8 ng/ml. For the other 3 diets, mean RBC folic acid levels were 90.7, 132.3 and 152.8 ng/ml, respectively. A megadose of 25.6 mg of folic acid per day for 99 days was given to 3 adult males. No obvious toxic effects were observed in these animals although mean RBC folic acid levels increased to 1013 ng/ml.

Mycotoxic peripheral myelinopathy, myopathy, and hepatitis caused by Diplodia maydis in vervet monkeys.

During recent historical times many Africans changed their diet to one based on maize. The grain is regularly contaminated by fungi which are toxigenic to domestic animals and birds. After one of the fungi, Diplodia maydis, in pure culture on maize, was added to the food of omnivorous primates there was demyelination of nerves, atrophy, degeneration and necrosis of muscle, and hepatitis. These preliminary results are applicable to veterinary and laboratory animal sciences. They may also be medically significant since neuromuscular syndromes of unknown cause are prevalent among Africans. Nerve conduction velocities and organ weights are defined for vervet monkeys.

Hormonal vaginal cytology of vervet monkeys.

The cellular proliferation and maturation of the vaginal epithelium of adult female Vervet monkeys was examined during their menstrual cycles. At the same time the serum contents of estrogen and progesterone were analysed. Gradual but distinct patterns demarcated the phases of the menstrual cycle cytologically. The karyopyknotic index paralleled the estrogen concentration. Mid-cycle peak maturation produced many anucleate squames, which exfoliated, forming a diagnostic vaginal discharge.