Jessie Pinchoff

Matching HIV, tuberculosis, viral hepatitis, and sexually transmitted diseases surveillance data, 2000-2010: identification of infectious disease syndemics in New York City.

CONTEXT In 2012, the New York City Department of Health and Mental Hygiene matched HIV, tuberculosis, viral hepatitis, and sexually transmitted disease surveillance data to identify the burden of infection with multiple diseases. METHODS HIV, tuberculosis, hepatitis B, hepatitis C, chlamydia, gonorrhea, and syphilis surveillance data from 2000 to 2010 were matched using a deterministic method. Data on deaths from the Department of Health and Mental Hygienes Office of Vital Statistics were also matched. RESULTS The final data set contained 840,248 people; 13% had 2 or more diseases. People with a report of syphilis had the highest proportion of matches with other diseases (64%), followed by gonorrhea (52%), HIV (31%), tuberculosis (23%), hepatitis C (20%), chlamydia (16%), and hepatitis B (11%). CONCLUSIONS The findings indicate several possible infectious disease syndemics in New York City and highlight the need to integrate surveillance data from different infectious disease programs. Conducting the match brought surveillance programs together to work collaboratively and has resulted in ongoing partnerships on programmatic activities that address multiple diseases.

Deaths Among People With Hepatitis C in New York City, 2000–2011

BACKGROUND Infection with hepatitis C virus (HCV) increases the risk of death from liver and nonliver-related diseases. Coinfection with human immunodeficiency virus (HIV) further increases this risk. METHODS Surveillance data (2000-2010) and mortality data (2000-2011) maintained by the New York City Department of Health and Mental Hygiene (DOHMH) were deterministically cross-matched. Factors associated with and causes of death among HCV-infected adult decedents were analyzed. RESULTS Between 2000 and 2011, 13 307 HCV-monoinfected adults died, and 5475 adults coinfected with HCV/HIV died. Decedents with HCV monoinfection were more likely to have died of liver cancer (odds ratio [OR] = 9.2), drug-related causes (OR = 4.3), and cirrhosis (OR = 3.7), compared with persons with neither infection. HCV/HIV-coinfected decedents were more likely to have died of liver cancer (OR = 2.2) and drug-related causes (OR = 3.1), compared with persons with neither infection. Among coinfected decedents, 53.6% of deaths were attributed to HIV/AIDS, and 94% of deaths occurred prematurely (before age 65). Among persons with HCV who died, more than half died within 3 years of an HCV report to DOHMH. CONCLUSIONS HCV-infected adults were at increased risk of dying and of dying prematurely, particularly from conditions associated with HCV, such as HIV/AIDS or drug use. The short interval between HCV report and death suggests a need for earlier testing and improved treatment.

Predictive Malaria Risk and Uncertainty Mapping in Nchelenge District, Zambia: Evidence of Widespread, Persistent Risk and Implications for Targeted Interventions.

Malaria risk maps may be used to guide policy decisions on whether vector control interventions should be targeted and, if so, where. Active surveillance for malaria was conducted through household surveys in Nchelenge District, Zambia from April 2012 through December 2014. Households were enumerated based on satellite imagery and randomly selected for study enrollment. At each visit, participants were administered a questionnaire and a malaria rapid diagnostic test (RDT). Logistic regression models were used to construct spatial prediction risk maps and maps of risk uncertainty. A total of 461 households were visited, comprising 1,725 participants, of whom 48% were RDT positive. Several environmental features were associated with increased household malaria risk in a multivariable logistic regression model adjusting for seasonal variation. The model was validated using both internal and external evaluation measures to generate and assess root mean square error, as well as sensitivity and specificity for predicted risk. The final, validated model was used to predict and map malaria risk including a measure of risk uncertainty. Malaria risk in a high, perennial transmission setting is widespread but heterogeneous at a local scale, with seasonal variation. Targeting malaria control interventions may not be appropriate in this epidemiological setting.

Targeting indoor residual spraying for malaria using epidemiological data: a case study of the Zambia experience

BackgroundIn Zambia and other sub-Saharan African countries affected by ongoing malaria transmission, indoor residual spraying (IRS) for malaria prevention has typically been implemented over large areas, e.g., district-wide, and targeted to peri-urban areas. However, there is a recent shift in some countries, including Zambia, towards the adoption of a more strategic and targeted IRS approach, in coordination with increased emphasis on universal coverage of long-lasting insecticidal nets (LLINs) and effective insecticide resistance management. A true targeted approach would deliver IRS to sub-district areas identified as high-risk, with the goal of maximizing the prevention of malaria cases and deaths.ResultsTogether with the Government of the Republic of Zambia, a new methodology was developed applying geographic information systems and satellite imagery to support a targeted IRS campaign during the 2014 spray season using health management information system data.Discussion/ConclusionThis case study focuses on the developed methodology while also highlighting the significant research gaps which must be filled to guide countries on the most effective strategy for IRS targeting in the context of universal LLIN coverage and evolving insecticide resistance.

Spatio-temporal heterogeneity of malaria vectors in northern Zambia: implications for vector control

BackgroundDespite large reductions in malaria burden across Zambia, some regions continue to experience extremely high malaria transmission. In Nchelenge District, Luapula Province, northern Zambia, almost half the human population carries parasites. Intervention coverage has increased substantially over the past decade, but comprehensive district-wide entomological studies to guide delivery of vector control measures are lacking. This study describes the bionomics and spatio-temporal patterns of malaria vectors in Nchelenge over a two and a half year period, investigates what household factors are associated with high vector densities and determines why vector control may not have been effective in the past to better guide future control efforts.MethodsBetween April 2012 and September 2014, twenty-seven households from across Nchelenge District were randomly selected for monthly light trap collections of mosquitoes. Anopheline mosquitoes were identified morphologically and molecularly to species. Foraging rates were estimated and sporozoite rates were determined by circumsporozoite ELISAs to calculate annual entomological inoculation rates. Blood feeding rates and host preference were determined by PCR. Zero-inflated negative binomial models measured environmental and household factors associated with mosquito abundance at study households such as season, proximity to the lake, and use of vector control measures.ResultsThe dominant species in Nchelenge was An. funestus (s.s.) with An. gambiae (s.s.) as a secondary vector. Both vectors were found together in large numbers across the district and the combined EIRs of the two vectors exceeded 80 infectious bites per person per annum. An. funestus household densities increased in the dry season whilst An. gambiae surged during the rains. Presence of insecticide treated nets (ITNs) and closed eaves in the houses were found to be associated with fewer numbers of An. gambiae but not An. funestus. There was no association with indoor residual spraying (IRS).ConclusionIn Nchelenge, the co-existence of two highly anthropophagic vectors, present throughout the year, is likely to be driving the high malaria transmission evident in the district. The vectors here have been shown to be highly resistant to pyrethroids used for IRS during the study. Vector control interventions in this area would have to be multifaceted and district-wide for effective control of malaria.

Factors Associated with Sustained Use of Long-Lasting Insecticide-Treated Nets Following a Reduction in Malaria Transmission in Southern Zambia

Understanding factors influencing sustained use of long-lasting insecticide-treated nets (LLIN) in areas of declining malaria transmission is critical to sustaining control and may facilitate elimination. From 2008 to 2013, 655 households in Choma District, Zambia, were randomly selected and residents were administered a questionnaire and malaria rapid diagnostic test. Mosquitoes were collected concurrently by light trap. In a multilevel model, children and adolescents of 5-17 years of age were 55% less likely to sleep under LLIN than adults (odds ratio [OR] = 0.45; 95% confidence interval [CI] = 0.35, 0.58). LLIN use was 80% higher during the rainy season (OR = 1.8; CI = 1.5, 2.2) and residents of households with three or more nets were over twice as likely to use a LLIN (OR = 2.1; CI = 1.4, 3.1). For every increase in 0.5 km from the nearest health center, the odds of LLIN use decreased 9% (OR = 0.9; CI = 0.88, 0.98). In a second multilevel model, the odds of LLIN use were more than twice high if more than five mosquitoes (anopheline and culicine) were captured in the house compared with households with no mosquitoes captured (OR = 2.1; CI = 1.1, 3.9). LLIN use can be sustained in low-transmission settings with continued education and distributions, and may be partially driven by the presence of nuisance mosquitoes.

Spatial clustering of measles cases during endemic (1998–2002) and epidemic (2010) periods in Lusaka, Zambia

BackgroundMeasles cases may cluster in densely populated urban centers in sub-Saharan Africa as susceptible individuals share spatially dependent risk factors and may cluster among human immunodeficiency virus (HIV)-infected children despite high vaccination coverage.MethodsChildren hospitalized with measles at the University Teaching Hospital (UTH) in Lusaka, Zambia were enrolled in the study. The township of residence was recorded on the questionnaire and mapped; SaTScan software was used for cluster detection. A spatial-temporal scan statistic was used to investigate clustering of measles in children hospitalized during an endemic period (1998 to 2002) and during the 2010 measles outbreak in Lusaka, Zambia.ResultsThree sequential and spatially contiguous clusters of measles cases were identified during the 2010 outbreak but no clustering among HIV-infected children was identified. In contrast, a space-time cluster among HIV-infected children was identified during the endemic period. This cluster occurred prior to the introduction of intensive measles control efforts and during a period between seasonal peaks in measles incidence.ConclusionsPrediction and early identification of spatial clusters of measles will be critical to achieving measles elimination. HIV infection may contribute to spatial clustering of measles cases in some epidemiological settings.

Individual and Household Level Risk Factors Associated with Malaria in Nchelenge District, a Region with Perennial Transmission: A Serial Cross-Sectional Study from 2012 to 2015

Background The scale-up of malaria control interventions has resulted in substantial declines in transmission in some but not all regions of sub-Saharan Africa. Understanding factors associated with persistent malaria transmission despite control efforts may guide targeted interventions to high-risk areas and populations. Methods Household malaria surveys were conducted in Nchelenge District, Luapula Province, in northern Zambia. Structures that appeared to be households were enumerated from a high-resolution satellite image and randomly sampled for enrollment. Households were enrolled into cross-sectional (single visit) or longitudinal (visits every other month) cohorts but analyses were restricted to cross-sectional visits and the first visit to longitudinal households. During study visits, a questionnaire was administered to adults and caretakers of children and a blood sample was collected for a malaria rapid diagnostic test (RDT) from all household residents. Characteristics associated with RDT positivity were analyzed using multi-level models. Results A total of 2,486 individuals residing within 742 households were enrolled between April 2012 and July 2015. Over this period, 51% of participants were RDT positive. Forty-three percent of all RDT positive individuals were between the ages of 5 and 17 years although this age group comprised only 30% of study participants. In a multivariable model, the odds being RDT positive were highest in 5–17 year olds and did not vary by season. Children 5–17 years of age had 8.83 higher odds of being RDT positive compared with those >18 years of age (95% CI: 6.13, 12.71); there was an interaction between age and report of symptoms, with an almost 50% increased odds of report of symptoms with decreasing age category (OR = 1.49; 95% CI 1.11, 2.00). Conclusions Children and adolescents between the ages of 5 and 17 were at the highest risk of malaria infection throughout the year. School-based programs may be effective at targeting this high-risk group.

Spatial and temporal changes in household structure locations using high-resolution satellite imagery for population assessment: an analysis in southern Zambia, 2006-2011

Satellite imagery is increasingly available at high spatial resolution and can be used for various purposes in public health research and programme implementation. Comparing a census generated from two satellite images of the same region in rural southern Zambia obtained four and a half years apart identified patterns of household locations and change over time. The length of time that a satellite image-based census is accurate determines its utility. Households were enumerated manually from satellite images obtained in 2006 and 2011 of the same area. Spatial statistics were used to describe clustering, cluster detection, and spatial variation in the location of households. A total of 3821 household locations were enumerated in 2006 and 4256 in 2011, a net change of 435 houses (11.4% increase). Comparison of the images indicated that 971 (25.4%) structures were added and 536 (14.0%) removed. Further analysis suggested similar household clustering in the two images and no substantial difference in concentration of households across the study area. Cluster detection analysis identified a small area where significantly more household structures were removed than expected; however, the amount of change was of limited practical significance. These findings suggest that random sampling of households for study participation would not induce geographic bias if based on a 4.5-year-old image in this region. Application of spatial statistical methods provides insights into the population distribution changes between two time periods and can be helpful in assessing the accuracy of satellite imagery.

Why don’t urban youth in Zambia use condoms? The influence of gender and marriage on non-use of male condoms among young adults

Background Zambia experiences high unmet need for family planning and high rates of HIV, particularly among youth. While male condoms are widely available and 95% of adults have heard of them, self-reported use in the past 12 months is low among young adults (45%). This study describes factors associated with non-use of male condoms among urban young adults in Zambia. Methods A household cross-sectional survey in four urban districts was conducted from November 2015 to January 2016 among sexually active young adults ages 18–24 years. A random walk strategy was implemented in urban areas; eligible, enrolled participants were administered a survey on household characteristics, health access, and knowledge, attitudes and practices related to contraception. Relative risk regression models were built to determine factors associated with the decision to not use a male condom (non-use) at most recent sexual intercourse. Results A total of 2,388 individuals were interviewed; 69% were female, 35% were married, and average lifetime sex partners was 3.45 (SD±6.15). Non-use of male condoms was 59% at most recent sexual intercourse. In a multivariate model, women were more likely to report non-use of a male condom compared with men (aRR = 1.24 [95% CI: 1.11, 1.38]), married individuals were more likely to report non-use compared with unmarried individuals (aRR = 1.59 [1.46, 1.73]), and those residing in the highest poverty wards were more likely to report non-use compared with those in the lowest poverty wards (aRR = 1.31 [1.16, 1.48]). Those with more negative perceptions of male condom use were 6% more likely to report non-use (aRR = 1.06 [1.03, 1.09]). Discussion regarding contraception with a partner decreased non-use 13% (aRR = 0.87 [0.80, 0.95]) and agreement regarding male condom use with a partner decreased non-use 16% (aRR = 0.84 [0.77, 0.91)]). Discussion Non-use of male condoms is high among young, married adults, particularly women, who may be interested in contraception for family planning but remain at risk of STI infection. Effective marketing strategy of dual protection methods to this population is critical.