Quantification of human interactions relevant to infectious disease transmission through social contact is central to predict disease dynamics, yet data from low-resource settings remain scarce.
METHODS
We undertook a social contact survey in rural Uganda, whereby participants were asked to recall details about the frequency, type, and socio-demographic characteristics of any conversational encounter that lasted for ≥5 min (henceforth defined as 'contacts') during the previous day. An estimate of the number of 'casual contacts' (i.e. < 5 min) was also obtained.
RESULTS
In total, 566 individuals were included in the study. On average participants reported having routine contact with 7.2 individuals (range 1-25). Children aged 5-14 years had the highest frequency of contacts and the elderly (≥65 years) the fewest (P < 0.001). A strong age-assortative pattern was seen, particularly outside the household and increasingly so for contacts occurring further away from home. Adults aged 25-64 years tended to travel more often and further than others, and males travelled more frequently than females.
CONCLUSION
Our study provides detailed information on contact patterns and their spatial characteristics in an African setting. It therefore fills an important knowledge gap that will help more accurately predict transmission dynamics and the impact of control strategies in such areas.
BACKGROUND
Deaths occurring during the neonatal period contribute close to half of under-five mortality rate (U5MR); over 80% of these deaths occur in low- and middle-income countries (LMICs). Poor maternal antepartum and perinatal health predisposes newborns to low birth weight (LBW), birth asphyxia, and infections which increase the newborn's risk of death.
METHODS
The objective of the study was to assess the association between abnormal postpartum maternal temperature and early infant outcomes, specifically illness requiring hospitalisation or leading to death between birth and six weeks' age. We prospectively studied a cohort of neonates born at Mbarara Regional Referral Hospital in Uganda to mothers with abnormal postpartum temperature and followed them longitudinally through early infancy. We performed a logistic regression of the relationship between maternal abnormal temperature and six-week infant hospitalization, adjusting for gestational age and 10-minute APGAR score at birth.
RESULTS
Of the 648 postpartum participants from the parent study who agreed to enroll their neonates in the sub-study, 100 (15%) mothers had abnormal temperature. The mean maternal age was 24.6 (SD 5.3) years, and the mean parity was 2.3 (SD 1.5). There were more preterm babies born to mothers with abnormal maternal temperature (10%) compared to 1.1% to mothers with normal temperature (p=˂0.001). While the majority of newborns (92%) had a 10-minute APGAR score > 7, 14% of newborns whose mothers had abnormal temperatures had APGAR score ˂7 compared to 7% of those born to mothers with normal postpartum temperatures (P = 0.02). Six-week outcome data was available for 545 women and their infants. In the logistic regression model adjusted for gestational age at birth and 10-minute APGAR score, maternal abnormal temperature was not significantly associated with the composite adverse infant health outcome (being unwell or dead) between birth and six weeks' age (aOR = 0.35, 95% CI 0.07-1.79, P = 0.21). The 10-minute APGAR score was significantly associated with adverse six-week outcome (P < 0.01).
CONCLUSIONS
While our results do not demonstrate an association between abnormal maternal temperature and newborn and early infant outcomes, good routine neonate care should be emphasized, and the infants should be observed for any abnormal findings that may warrant further assessment.
People living with HIV are considered at higher risk of developing severe forms of tuberculosis (TB) disease. Providing HIV testing to TB-exposed people is therefore critical. We present the results of integrating HIV testing into a community-based intervention for household TB contact management in Cameroon and Uganda.
METHODS
Trained community health workers visited the households of index patients with TB identified in 3 urban/semiurban and 6 rural districts or subdistricts as part of a cluster-randomized trial and provided TB screening to all household contacts. Voluntary HIV counseling and testing were offered to contacts aged 5 years or older with unknown HIV status. We describe the cascade of care for HIV testing and the factors associated with the acceptance of HIV testing.
RESULTS
Overall, 1983 household contacts aged 5 years or older were screened for TB. Of these contacts, 1652 (83.3%) did not know their HIV status, 1457 (88.2%) accepted HIV testing, and 1439 (98.8%) received testing. HIV testing acceptance was lower among adults than children [adjusted odds ratio (aOR) = 0.35, 95% confidence interval (CI): 0.22 to 0.55], those living in household of an HIV-positive vs HIV-negative index case (aOR = 0.56, 95% CI: 0.38 to 0.83), and contacts requiring a reassessment visit after the initial TB screening visit vs asymptomatic contacts (aOR = 0.20, 95% CI: 0.06 to 0.67) and was higher if living in Uganda vs Cameroon (aOR = 4.54, 95% CI: 1.17 to 17.62) or if another contact of the same index case was tested for HIV (aOR = 9.22, 95% CI: 5.25 to 16.18).
CONCLUSION
HIV testing can be integrated into community-based household TB contact screening and is well-accepted.
Therapeutic efficacy studies in uncomplicated Plasmodium falciparum malaria are confounded by new infections, which constitute competing risk events since they can potentially preclude/pre-empt the detection of subsequent recrudescence of persistent, sub-microscopic primary infections.
METHODS
Antimalarial studies typically report the risk of recrudescence derived using the Kaplan-Meier (K-M) method, which considers new infections acquired during the follow-up period as censored. Cumulative Incidence Function (CIF) provides an alternative approach for handling new infections, which accounts for them as a competing risk event. The complement of the estimate derived using the K-M method (1 minus K-M), and the CIF were used to derive the risk of recrudescence at the end of the follow-up period using data from studies collated in the WorldWide Antimalarial Resistance Network data repository. Absolute differences in the failure estimates derived using these two methods were quantified. In comparative studies, the equality of two K-M curves was assessed using the log-rank test, and the equality of CIFs using Gray's k-sample test (both at 5% level of significance). Two different regression modelling strategies for recrudescence were considered: cause-specific Cox model and Fine and Gray's sub-distributional hazard model.
RESULTS
Data were available from 92 studies (233 treatment arms, 31,379 patients) conducted between 1996 and 2014. At the end of follow-up, the median absolute overestimation in the estimated risk of cumulative recrudescence by using 1 minus K-M approach was 0.04% (interquartile range (IQR): 0.00-0.27%, Range: 0.00-3.60%). The overestimation was correlated positively with the proportion of patients with recrudescence [Pearson's correlation coefficient (ρ): 0.38, 95% Confidence Interval (CI) 0.30-0.46] or new infection [ρ: 0.43; 95% CI 0.35-0.54]. In three study arms, the point estimates of failure were greater than 10% (the WHO threshold for withdrawing antimalarials) when the K-M method was used, but remained below 10% when using the CIF approach, but the 95% confidence interval included this threshold.
CONCLUSIONS
The 1 minus K-M method resulted in a marginal overestimation of recrudescence that became increasingly pronounced as antimalarial efficacy declined, particularly when the observed proportion of new infection was high. The CIF approach provides an alternative approach for derivation of failure estimates in antimalarial trials, particularly in high transmission settings.