A review of the enhanced CJD surveillance feasibility study in the elderly in Scotland, UK.

BACKGROUND: Variant Creutzfeldt - Jakob disease (vCJD) arose from dietary contamination with bovine-spongiform-encephalopathy (BSE). Because of concerns that vCJD-cases might be missed in the elderly, a feasibility study of enhanced CJD surveillance on the elderly was begun in 2016. Recruitment was lower than predicted. We describe a review of the challenges encountered in that study: identification, referral, and recruitment, and the effects of actions based on the results of that review. METHODS: Review was conducted in 2017. Study data for all eligible cases identified and referred from one participating service (Anne Rowling clinic (ARC)) was curated and anonymised in a bespoke database. A questionnaire was sent out to all the clinicians in medicine of the elderly, psychiatry of old age and neurology (including ARC) specialties in NHS Lothian, exploring possible reasons for low recruitment. RESULTS: Sixty-eight cases were referred from the ARC (March 2016-September 2017): 25% were recruited. Most cases had been referred because of diagnostic uncertainty. No difference was seen between those recruited and the non-recruited, apart from age and referrer. Twelve of 60 participating clinicians completed the questionnaire: only 4 had identified eligible cases. High workload, time constraints, forgetting to refer, unfamiliarity with the eligibility criteria, and the rarity of eligible cases, were some of the reasons given. Suggestions as to how to improve referral of eligible cases included: regular email reminders, feedback to referrers, improving awareness of the study, visible presence of the study team, and integration of the study with other research oriented services. These results were used to increase recruitment but without success. CONCLUSION: Recruitment was lower than predicted. Actions taken following a review at 21 months did not lead to significant improvement; recruitment remained low, with many families/patients declining to take part (75%). In assessing the failure to improve recruitment, two factors need to be considered. Firstly, the initial referral rate was expected to be higher because of existing patients already known to the clinical services, with later referrals being only newly presenting patients. Secondly, the unplanned absence of a dedicated study nurse. Searching digital records/anonymised derivatives to identify eligible patients could be explored.

Enhanced Creutzfeldt-Jakob disease surveillance in the older population: Assessment of a protocol for screening brain tissue donations for prion disease.

Human prion diseases, including Creutzfeldt-Jakob disease (CJD), occur in sporadic, genetic, and acquired forms. Variant Creutzfeldt-Jakob disease (vCJD) first reported in 1996 in the United Kingdom (UK), resulted from contamination of food with bovine spongiform encephalopathy. There is a concern that UK national surveillance mechanisms might miss some CJD cases (including vCJD), particularly in the older population where other neurodegenerative disorders are more prevalent. We developed a highly sensitive protocol for analysing autopsy brain tissue for the misfolded prion protein (PrPSc ) associated with prion disease, which could be used to screen for prion disease in the elderly. Brain tissue samples from 331 donors to the Edinburgh Brain and Tissue Bank (EBTB), from 2005 to 2022, were analysed, using immunohistochemical analysis on fixed tissue, and five biochemical tests on frozen specimens from six brain regions, based on different principles for detecting PrPSc . An algorithm was established for classifying the biochemical results. To test the effectiveness of the protocol, several neuropathologically confirmed prion disease controls, including vCJD, were included and blinded in the study cohort. On unblinding, all the positive control cases had been correctly identified. No other cases tested positive; our analysis uncovered no overlooked prion disease cases. Our algorithm for classifying cases was effective for handling anomalous biochemical results. An overall analysis suggested that a reduced biochemical protocol employing only three of the five tests on only two brain tissue regions gave sufficient sensitivity and specificity. We conclude that this protocol may be useful as a UK-wide screening programme for human prion disease in selected brains from autopsies in the elderly. Further improvements to the protocol were suggested by enhancements of the in vitro conversion assays made during the course of this study.

A clinicopathological study of selected cognitive impairment cases in Lothian, Scotland: enhanced CJD surveillance in the 65 + population group.

BACKGROUND: Variant Creutzfeldt-Jakob Disease (vCJD) is primarily associated with dietary exposure to bovine-spongiform-encephalopathy. Cases may be missed in the elderly population where dementia is common with less frequent referral to specialist neurological services. This study's twin aims were to determine the feasibility of a method to detect possible missed cases in the elderly population and to identify any such cases. METHODS: A multi-site study was set-up in Lothian in 2016, to determine the feasibility of enhanced CJD-surveillance in the 65 + population-group, and undertake a clinicopathological investigation of patients with features of 'atypical' dementia. RESULTS: Thirty patients are included; 63% male, 37% female. They were referred because of at least one neurological feature regarded as 'atypical' (for the common dementing illnesses): cerebellar ataxia, rapid progression, or somato-sensory features. Mean-age at symptom-onset (66 years, range 53-82 years), the time between onset-of-symptoms and referral to the study (7 years, range 1-13 years), and duration-of-illness from onset-of-symptoms until death or the censor-date (9.5 years, range 1.1-17.4 years) were determined. By the censor-date, 9 cases were alive and 21 had died. Neuropathological investigations were performed on 10 cases, confirming: Alzheimer's disease only (2 cases), mixed Alzheimer's disease with Lewy bodies (2 cases), mixed Alzheimer's disease with amyloid angiopathy (1 case), moderate non-amyloid small vessel angiopathy (1 case), a non-specific neurodegenerative disorder (1 case), Parkinson's disease with Lewy body dementia (1 case), and Lewy body dementia (2 cases). No prion disease cases of any type were detected. CONCLUSION: The surveillance approach used was well received by the local clinicians and patients, though there were challenges in recruiting sufficient cases; far fewer than expected were identified, referred, and recruited. Further research is required to determine how such difficulties might be overcome. No missed cases of vCJD were found. However, there remains uncertainty whether this is because missed cases are very uncommon or because the study had insufficient power to detect them.

Non-white cases of sporadic Creutzfeldt-Jakob disease: A 28 year review of United Kingdom National Surveillance Data.

AIMS: Descriptions of sporadic Creutzfeldt-Jakob disease (sCJD) in non-White populations are limited. Improved understanding may aid diagnoses and case ascertainment within surveillance programmes. We aimed to: 1) Ascertain the proportion of sCJD cases with non-White ethnicity in the United Kingdom (UK); 2) Compare clinical and investigation findings between non-White and White cases. METHODS: We analysed records of probable and definite sCJD cases assessed by the UK National CJD Research and Surveillance Unit over 28 years (1990-2017). Cases were stratified into White and non-White groups. Demographics, clinical features, investigation findings, and post-mortem numbers were compared. RESULTS: 1697 sCJD cases were included: 1642 (97%) White, 55 (3%) non-White (Asian/Asian British, Black/African/Caribbean). The proportion of non-Whites among sCJD cases is 7% lower than the proportion the non-White population make up in the UK (p < 0.001). This was not statistically significant when age-matched by ≥60 years (p = 0.071). Age at symptom onset was 4 years lower in the non-White population (p = 0.007). Clinical and investigation characteristics were otherwise similar between ethnic groupings. The proportion of non-Whites undergoing autopsy and classification as definite was 30% and 24% lower (p < 0.001) respectively in comparison to those for White cases. CONCLUSIONS: Approximately 3% of sCJD cases in the UK are non-White, despite non-Whites representing approximately 10% of the UK population. This difference was not statistically significant when age-matched at ≥60 years. Non-White cases tend to be younger and likelihood of autopsy is lower; relevant considerations for surveillance programmes. Reasons for these differences in non-White populations are unclear and merit further evaluation.

Study protocol for enhanced CJD surveillance in the 65+ years population group in Scotland: an observational neuropathological screening study of banked brain tissue donations for evidence of prion disease.

INTRODUCTION: Creutzfeldt-Jakob disease (CJD) is a human prion disease that occurs in sporadic, genetic and acquired forms. Variant CJD (vCJD) is an acquired form first identified in 1996 in the UK. To date, 178 cases of vCJD have been reported in the UK, most of which have been associated with dietary exposure to the bovine spongiform encephalopathy agent. Most vCJD cases have a young age of onset, with a median age at death of 28 years. In the UK, suspected cases of vCJD are reported to the UK National Creutzfeldt-Jakob Disease Research & Surveillance Unit (NCJDRSU). There is, however, a concern that the national surveillance system might be missing some cases of vCJD or other forms of human prion disease, particularly in the older population, perhaps because of atypical clinical presentation. This study aims to establish whether there is unrecognised prion disease in people aged 65 years and above in the Scottish population by screening banked brain tissue donated to the Edinburgh Brain Bank (EBB). METHODS: Neuropathological screening of prospective and retrospective brain tissue samples is performed. This involves histopathological and immunohistochemical analysis and prion protein biochemical analysis. During the study, descriptive statistics are used to describe the study population, including the demographics and clinical, pathological and referral characteristics. Controlling for confounders, univariate and multivariate analyses will be used to compare select characteristics of newly identified suspect cases with previously confirmed cases referred to the NCJDRSU. ETHICS AND DISSEMINATION: Brain tissue donations to EBB are made voluntarily by the relatives of patients, with consent for use in research. The EBB has ethical approval to provide tissue samples to research projects (REC reference 16/ES/0084). The findings of this study will be disseminated in meetings, conferences, workshops and as peer-reviewed publications. TRIAL REGISTRATION NUMBERS: 10/S1402/69 and 10/S1402/70.

Public health: surveillance, infection prevention, and control.

Human prion diseases, though relatively rare, remain an ongoing public health problem. They are fatal diseases, with unconventional host responses and no early diagnostic tests or robust treatments. Public health measures were put in place to protect the food chain in the United Kingdom from the late 1980s, with similar measures following elsewhere. However, human prion diseases are transmissible through other routes, including through blood transfusion and surgery. As a result, the public health threat remains for all forms of human prion diseases and makes continued surveillance and infection prevention and control imperative.

Sporadic Creutzfeldt-Jakob Disease in 2 Plasma Product Recipients, United Kingdom.

Sporadic Creutzfeldt-Jakob disease (sCJD) has not been previously reported in patients with clotting disorders treated with fractionated plasma products. We report 2 cases of sCJD identified in the United Kingdom in patients with a history of extended treatment for clotting disorders; 1 patient had hemophilia B and the other von Willebrand disease. Both patients had been informed previously that they were at increased risk for variant CJD because of past treatment with fractionated plasma products sourced in the United Kingdom. However, both cases had clinical and investigative features suggestive of sCJD. This diagnosis was confirmed in both cases on neuropathologic and biochemical analysis of the brain. A causal link between the treatment with plasma products and the development of sCJD has not been established, and the occurrence of these cases may simply reflect a chance event in the context of systematic surveillance for CJD in large populations.

Unintended Childbearing and Child Growth in Northern Malawi.

Objective The study aims to assess whether unintended children experience slower growth than intended children. Methods We analysed longitudinal data linked to the Karonga Health and Demographic Surveillance Site collected over three rounds between 2008 and 2011 on women's fertility intentions and anthropometric data of children. Using the prospective information on fertility intention we assessed whether unintended children are more likely to be stunted than intended children. We applied Propensity Score Matching technique to control for endogenous factors affecting both the probability that a family has an unwanted birth and a child with poor health outcomes. Results We found that 24 % of children from unwanted pregnancies were stunted compared with 18 % of mistimed pregnancies and 17 % of those from wanted pregnancies. However, these differences in probability of children being stunted, though in the expected direction, were not significant either for large or small families, after controlling for age. The number of children in the household was associated with stunting and boys were substantially more likely to be stunted than girls. Conclusion We found no significance difference in probability of being stunted by mother's fertility intention.

Human Immunodeficiency Virus, Antiretroviral Therapy and Markers of Lymphatic Filariasis Infection: A Cross-sectional Study in Rural Northern Malawi.

BACKGROUND: Lymphatic filariasis (LF) and human immunodeficiency virus (HIV) are major public health problems. Individuals may be co-infected, raising the possibility of important interactions between these two pathogens with consequences for LF elimination through annual mass drug administration (MDA). METHODOLOGY AND PRINCIPAL FINDINGS: We analysed circulating filarial antigenaemia (CFA) by HIV infection status among adults in two sites in northern Malawi, a region endemic for both LF and HIV. Stored blood samples and data from two geographically separate studies were used: one a recruitment phase of a clinical trial of anti-filarial agent dosing regimens, and the other a whole population annual HIV sero-survey. In study one, 1,851 consecutive adult volunteers were screened for HIV and LF infection. CFA prevalence was 25.4% (43/169) in HIV-positive and 23.6% (351/1487) in HIV-negative participants (p=0.57). Geometric mean CFA concentrations were 859 and 1660 antigen units per ml of blood (Ag/ml) respectively, geometric mean ratio (GMR) 0.85, 95%CI 0.49-1.50. In 7,863 adults in study two, CFA prevalence was 20.9% (86/411) in HIV-positive and 24.0% (1789/7452) in HIV-negative participants (p=0.15). Geometric mean CFA concentrations were 630 and 839 Ag/ml respectively (GMR 0.75, 95%CI 0.60-0.94). In the HIV-positive group, antiretroviral therapy (ART) use was associated with a lower CFA prevalence, 12.7% (18/142) vs. 25.3% (67/265), (OR 0.43, 95%CI 0.24-0.76). Prevalence of CFA decreased with duration of ART use, 15.2% 0-1 year (n=59), 13.6% >1-2 years (n=44), 10.0% >2-3 years (n=30) and 0% >3-4 years treatment (n=9), p<0.01 χ2 for linear trend. CONCLUSIONS/SIGNIFICANCE: In this large cross-sectional study of two distinct LF-exposed populations, there is no evidence that HIV infection has an impact on LF epidemiology that will interfere with LF control measures. A significant association of ART use with lower CFA prevalence merits further investigation to understand this apparent beneficial impact of ART.

Investigation of variant Creutzfeldt-Jakob disease implicated organ or tissue transplantation in the United Kingdom.

BACKGROUND: Person-to-person transmission of variant Creutzfeldt-Jakob disease (vCJD) has occurred through blood transfusion and could also theoretically occur as a result of the transplantation of organs or tissues. This study aimed to investigate whether there were transplant-associated vCJD cases in the United Kingdom (UK). METHODS: Medical histories were reviewed for 177 UK vCJD cases to identify situations where the transplantation of organs or tissues might have occurred. A "look-back" was then performed to trace the respective donors or recipients of the implicated organ or tissue. RESULTS: A single patient had undergone an organ (liver) transplant before vCJD onset, from a donor who had died of causes unrelated to vCJD. The look-back was able to trace six other organ or tissue donations made by the same donor. No other situations were identified where the receipt or donation of organs or tissues had occurred in people who went on to develop vCJD. There was considered no need, on this particular occasion, to implement public health measures associated with the organ transplantation, beyond those already in place. CONCLUSIONS: This study provides no evidence of transplant-associated vCJD in the UK. It is, however, important to continue to seek to identify individuals who might be at risk of vCJD by this route so that appropriate public health measures can be implemented.

Underestimation of HIV prevalence in surveys when some people already know their status, and ways to reduce the bias.

OBJECTIVE: To quantify refusal bias due to prior HIV testing, and its effect on HIV prevalence estimates, in general-population surveys. DESIGN: Four annual, cross-sectional, house-to-house HIV serosurveys conducted during 2006-2010 within a demographic surveillance population of 33 000 in northern Malawi. METHODS: The effect of prior knowledge of HIV status on test acceptance in subsequent surveys was analysed. HIV prevalence was then estimated using ten adjustment methods, including age-standardization; multiple imputation of missing data; a conditional probability equations approach incorporating refusal bias; using longitudinal data on previous and subsequent HIV results; including self-reported HIV status; and including linked antiretroviral therapy clinic data. RESULTS: HIV test acceptance was 55-65% in each serosurvey. By 2009/2010 79% of men and 85% of women had tested at least once. Known HIV-positive individuals were more likely to be absent, and refuse interviewing and testing. Using longitudinal data, and adjusting for refusal bias, the best estimate of HIV prevalence was 7% in men and 9% in women in 2008/2009. Estimates using multiple imputations were 4.8 and 6.4%, respectively. Using the conditional probability approach gave good estimates using the refusal risk ratio of HIV-positive to HIV-negative individuals observed in this study, but not when using the only previously published estimate of this ratio, even though this was also from Malawi. CONCLUSION: As the proportion of the population who know their HIV-status increases, survey-based prevalence estimates become increasingly biased. As an adjustment method for cross-sectional data remains elusive, sources of data with high coverage, such as antenatal clinics surveillance, remain important.

Antiretroviral therapy uptake and coverage in four HIV community cohort studies in sub-Saharan Africa.

OBJECTIVE: To compare socio-demographic patterns in access to antiretroviral therapy (ART) across four community HIV cohort studies in Africa. METHODS: Data on voluntary counselling and testing and ART use among HIV-infected persons were analysed from Karonga (Malawi), Kisesa (Tanzania), Masaka (Uganda) and Manicaland (Zimbabwe), where free ART provision started between 2004 and 2007. ART coverage was compared across sites by calculating the proportion on ART among those estimated to need treatment, by age, sex and educational attainment. Logistic regression was used to identify socio-demographic characteristics associated with undergoing eligibility screening at an ART clinic within 2 years of being diagnosed with HIV, for three sites with information on diagnosis and screening dates. RESULTS: Among adults known to be HIV-infected from serological surveys, the proportion who knew their HIV status was 93% in Karonga, 37% in Kisesa, 46% in Masaka and 25% in Manicaland. Estimated ART coverage was highest in Masaka (68%) and lowest in Kisesa (2%). The proportion of HIV-diagnosed persons who were screened for ART eligibility within 2 years of diagnosis ranged from 14% in Kisesa to 84% in Masaka, with the probability of screening uptake increasing with age at diagnosis in all sites. CONCLUSIONS: Higher HIV testing rates among HIV-infected persons in the community do not necessarily correspond with higher uptake of ART, nor more equitable treatment coverage among those in need of treatment. In all sites, young adults tend to be disadvantaged in terms of accessing and initiating ART, even after accounting for their less urgent need.

Adult mortality and probable cause of death in rural northern Malawi in the era of HIV treatment.

OBJECTIVES: Developing countries are undergoing demographic transition with a shift from high mortality caused by communicable diseases (CD) to lower mortality rates caused by non-communicable diseases (NCD). HIV/AIDS has disrupted this trend in sub-Saharan Africa. However, in recent years, HIV-associated mortality has been reduced with the introduction of widely available antiretroviral therapy (ART). Side effects of ART may lead to increased risk of cardiovascular diseases, raising the prospects of an accelerated transition towards NCD as the primary cause of death. We report population-based data to investigate changes in cause of death owing to NCD during the first 4 years after introduction of HIV treatment. METHODS: We analysed data from a demographic surveillance system in Karonga district, Malawi, from September 2004 to August 2009. ART was introduced in mid-2005. Clinician review of verbal autopsies conducted 2-6 weeks after a death was used to establish a single principal cause of death. RESULTS: Over the entire period, there were 905 deaths, AIDS death rate fell from 505 to 160/100,000 person-years, and there was no evidence of an increase in NCD rates. The proportion of total deaths attributable to AIDS fell from 42% to 17% and from NCD increased from 37% to 49%. DISCUSSION: Our findings show that 4 years after the introduction of ART into HIV care in Karonga district, all-cause mortality has fallen dramatically, with no evidence of an increase in deaths owing to NCD.

Profile: the Karonga Health and Demographic Surveillance System.

The Karonga Health and Demographic Surveillance System (Karonga HDSS) in northern Malawi currently has a population of more than 35 000 individuals under continuous demographic surveillance since completion of a baseline census (2002-2004). The surveillance system collects data on vital events and migration for individuals and for households. It also provides data on cause-specific mortality obtained by verbal autopsy for all age groups, and estimates rates of disease for specific presentations via linkage to clinical facility data. The Karonga HDSS provides a structure for surveys of socio-economic status, HIV sero-prevalence and incidence, sexual behaviour, fertility intentions and a sampling frame for other studies, as well as evaluating the impact of interventions, such as antiretroviral therapy and vaccination programmes. Uniquely, it relies on a network of village informants to report vital events and household moves, and furthermore is linked to an archive of biological samples and data from population surveys and other studies dating back three decades.

Measuring concurrency: an empirical study of different methods in a large population-based survey and evaluation of the UNAIDS guidelines.

BACKGROUND: Recent UNAIDS guidelines recommend measuring concurrency 6 months before the interview date, based on overlapping partnership dates. This has theoretical advantages, but little is known about how well it can be measured in practice. METHODS: The assumptions underlying the UNAIDS measure were tested using data from a sexual behaviour survey conducted in rural northern Malawi. All resident adults aged 15-59 were eligible. Questions included self-reported concurrency and dates for all marital and nonmarital partnerships in the past 12 months. RESULTS: A total of 6796 women and 5253 men were interviewed, 83 and 72% of those eligible, respectively. Since few women reported multiple partners, detailed analysis was restricted to men. Overall 19.2% [95% confidence interval (CI) 18.1-20.2] of men self-reported concurrent relationships in the past year (almost all of those with more than one partner). Using overlapping dates the estimate was 16.7% (15.7-17.7). Excluding partnerships which tied on dates (making overlap uncertain) or restricting the analysis to the three most recent partners gave similar results. The UNAIDS 6-month measure was 12.0% (11.1-12.9), and current concurrency was 11.5% (10.6-12.4). The difference between dates-based and self-reported 12-month measures was much larger for unmarried men: 11.1% (9.7-12.4) self-reported; 7.1% (6.9-8.2) on dates. Polygyny (15% of married men) and the longer duration of relationships stabilized the estimates for married men. Nonmarital partnerships were under-reported, particularly those starting longer ago. CONCLUSIONS: The difficulties of recall of dates for relationships, and under-reporting of partners lead to underestimation of concurrency using date-based measures. Self-reported concurrency is much easier to measure and appears more complete.

Fertility intentions and use of contraception among monogamous couples in northern Malawi in the context of HIV testing: a cross-sectional analysis.

CONTEXT: Knowledge of HIV status may influence fertility desires of married men and women. There is little knowledge about the importance of this influence among monogamously married couples and how knowledge of HIV status influences use of contraception among these couples. METHODOLOGY: We carried out a cross-sectional analysis of interview data collected between October 2008 and September 2009 on men aged 15-59 years and women aged 15-49 years who formed 1766 monogamously married couples within the Karonga Prevention Study demographic surveillance study in northern Malawi. RESULTS: 5% of men and 4% of women knew that they were HIV positive at the time of interview and 81% of men and 89% of women knew that they were HIV negative. 73% of men and 83% of women who knew that they were HIV positive stated that they did not want more children, compared to 35% of men and 38% of women who knew they were HIV negative. Concordant HIV positive couples were more likely than concordant negative couples to desire to stop child bearing (odds ratio 11.5, 95%CI 4.3-30.7, after adjusting for other factors) but only slightly more likely to use contraceptives (adjusted odds ratio 1.5 (95%CI 0.8-3.3). CONCLUSION: Knowledge of HIV positive status is associated with an increase in the reported desire to cease childbearing but there was limited evidence that this desire led to higher use of contraception. More efforts directed towards assisting HIV positive couples to access and use reproductive health services and limit HIV transmission among couples are recommended.

Assessing the validity of sexual behaviour reports in a whole population survey in rural Malawi.

BACKGROUND: Sexual behaviour surveys are widely used, but under-reporting of particular risk behaviours is common, especially by women. Surveys in whole populations provide an unusual opportunity to understand the extent and nature of such under-reporting. METHODS: All consenting individuals aged between 15 and 59 within a demographic surveillance site in northern Malawi were interviewed about their sexual behaviour. Validity of responses was assessed by analysis of probing questions; by comparison of results with in-depth interviews and with Herpes simplex type-2 (HSV-2) seropositivity; by comparing reports to same sex and opposite sex interviewers; and by quantifying the partnerships within the local community reported by men and by women, adjusted for response rates. RESULTS: 6,796 women and 5,253 men (83% and 72% of those eligible) consented and took part in sexual behaviour interviews. Probing questions and HSV-2 antibody tests in those who denied sexual activity identified under-reporting for both men and women. Reports varied little by sex or age of the interviewer. The number of marital partnerships reported was comparable for men and women, but men reported about 4 times as many non-marital partnerships. The discrepancy in reporting of non-marital partnerships was most marked for married women (men reported about 7 times as many non-marital partnerships with married women as were reported by married women themselves), but was only apparent in younger married women. CONCLUSIONS: We have shown that the under-reporting of non-marital partnerships by women was strongly age-dependent. The extent of under-reporting of sexual activity by young men was surprisingly high. The results emphasise the importance of triangulation, including biomarkers, and the advantages of considering a whole population.

Drug resistance mutations in drug-naive HIV type 1 subtype C-infected individuals from rural Malawi.

In this preliminary study we show that in 2008, 3 years after antiretroviral therapy was introduced into the Karonga District, Malawi, a greater than expected number of drug-naive individuals have been infected with HIV-1 subtype C virus harboring major and minor drug resistance mutations (DRMs). From a sample size of 40 reverse transcriptase (RT) consensus sequences from drug-naive individuals we found five showing NRTI and four showing NNRTI mutations with one individual showing both. From 29 protease consensus sequences, again from drug-naive individuals, we found evidence of minor DRMs in three. Additional major and minor DRMs were found in clonal sequences from a number of individuals that were not present in the original consensus sequences. This clearly illustrates the importance of sequencing multiple HIV-1 variants from individuals to fully assess drug resistance.

Age at menarche, schooling, and sexual debut in northern Malawi.

BACKGROUND: Age at sexual debut is a key behavioural indicator used in HIV behavioural surveillance. Early age at menarche may precipitate early sex through perceived readiness for sex, or through school drop-out, but this is rarely studied. We investigated trends and circumstances of sexual debut in relation to schooling and age at menarche. METHODS AND FINDINGS: A cross-sectional sexual behaviour survey was conducted on all individuals age 15-59 within a demographic surveillance site in Karonga District, Malawi. Time trends were assessed using birth cohorts. Survival analysis was used to estimate the median age at menarche, sexual debut and first marriage. The 25(th) centile was used to define "early" sex, and analyses of risk factors for early sex were restricted to those who had reached that age, and were done using logistic regression. Of the 8232 women and 7338 men resident in the area, 88% and 78%, respectively, were seen, and, 94% and 92% of these were interviewed. The median reported age at first sex was 17.5 for women and 18.8 for men. For women, ages at menarche, sexual debut and first marriage did not differ by birth cohort. For men, age at sexual debut and first marriage decreased slightly in later birth cohorts. For both men and women increased schooling was associated with later sexual debut and a longer delay between sexual debut and first marriage, but the associations were stronger for women. Earlier age at menarche was strongly associated with earlier sexual debut and marriage and lower schooling levels. In women early sexual debut (<16 years) was less likely in those with menarche at age 14-15 (odds ratio (OR) 0.31, 95%CI 0.26-0.36), and ≥16 (OR 0.04, 95%CI 0.02-0.05) compared to those with menarche at <14. The proportion of women who completed primary school was 46% in those with menarche at <14, 60% in those with menarche at 14-15 and 70% in those with menarche at ≥16. The association between age at menarche and schooling was partly explained by age at sexual debut. The association between age at menarche and early sex was not altered by adjusting for schooling. CONCLUSIONS: Women with early menarche start sex and marry early, leading to school drop-out. It is important to find ways to support those who reach menarche early to access the same opportunities as other young women.