Comparative analysis of cholera serum vibriocidal antibodies from Convalescent and vaccinated adults in Zambia

Cholera is responsible for 1.3 to 4.0 million cholera cases globally and poses a significant threat, with Zambia reporting 17,169 cases as of 4th February 2024. Recognizing the crucial link between natural cholera infections and vaccine protection, this study aimed to assess immune responses post cholera infection and vaccination. This was a comparative study consisting of 50 participants enrolled during a cholera outbreak in Zambia's Eastern Province and an additional 56 participants who received oral cholera vaccinations in Zambia's Central Province. Vibriocidal antibodies were plotted as geometric mean titres in the naturally infected and vaccinated individuals. A significant difference (p < 0.047) emerged when comparing naturally infected to fully vaccinated individuals (2 doses) on day 28 against V. cholerae Ogawa. Those who received two doses of the oral cholera vaccine had higher antibody titres than those who were naturally infected. Notably, the lowest titres occurred between 0-9 days post onset, contrasting with peak responses at 10-19 days. This study addresses a critical knowledge gap in understanding cholera immunity dynamics, emphasizing the potential superiority of vaccination-induced immune responses. We recommend post infection vaccination after 40 days for sustained immunity and prolonged protection, especially in cholera hotspots.

Seroconversion and Kinetics of Vibriocidal Antibodies during the First 90 Days of Re-Vaccination with Oral Cholera Vaccine in an Endemic Population

Despite the successful introduction of oral cholera vaccines, Zambia continues to experience multiple, sporadic, and protracted cholera outbreaks in various parts of the country. While vaccines have been useful in staying the cholera outbreaks, the ideal window for re-vaccinating individuals resident in cholera hotspot areas remains unclear. Using a prospective cohort study design, 225 individuals were enrolled and re-vaccinated with two doses of Shanchol™, regardless of previous vaccination, and followed-up for 90 days. Bloods were collected at baseline before re-vaccination, at day 14 prior to second dosing, and subsequently on days 28, 60, and 90. Vibriocidal assay was performed on samples collected at all five time points. Our results showed that anti-LPS and vibriocidal antibody titers increased at day 14 after re-vaccination and decreased gradually at 28, 60, and 90 days across all the groups. Seroconversion rates were generally comparable in all treatment arms. We therefore conclude that vibriocidal antibody titers generated in response to re-vaccination still wane quickly, irrespective of previous vaccination status. However, despite the observed decline, the levels of vibriocidal antibodies remained elevated over baseline values across all groups, an important aspect for Zambia where there is no empirical evidence as to the ideal time for re-vaccination.

The Incidence and Risk Factors for Enterotoxigenic E. coli Diarrheal Disease in Children under Three Years Old in Lusaka, Zambia

This study aimed to estimate the incidence and risk factors for Enterotoxigenic Escherichia coli (ETEC) diarrhea. This was a prospective cohort study of children recruited in a household census. Children were enrolled if they were 36 months or below. A total of 6828 children were followed up passively for 12 months to detect episodes of ETEC diarrhea. Diarrheal stool samples were tested for ETEC using colony polymerase chain reaction (cPCR). Among the 6828 eligible children enrolled, a total of 1110 presented with at least one episode of diarrhea. The overall incidence of ETEC diarrhea was estimated as 2.47 (95% confidence interval (CI): 2.10-2.92) episodes per 100 child years. Children who were HIV-positive (adjusted Hazard ratio (aHR) = 2.14, 95% CI: 1.14 to 3.99; p = 0.017) and those whose source of drinking water was public tap/borehole/well (aHR = 2.45, 95% CI: 1.48 to 4.06; p < 0.002) were at increased risk of ETEC diarrhea. This study found that children whose mothers have at least senior secondary school education (aHR = 0.49, 95% CI: 0.29 to 0.83; p = 0.008) were at decreased risk of ETEC diarrhea. Our study emphasizes the need for integrated public health strategies focusing on water supply improvement, healthcare for persons living with HIV, and maternal education.

Associations of inter-annual rainfall decreases with subsequent HIV outcomes for persons with HIV on antiretroviral therapy in Southern Africa: a collaborative analysis of cohort studies

BACKGROUND

Periods of droughts can lead to decreased food security, and altered behaviours, potentially affecting outcomes on antiretroviral therapy (ART) among persons with HIV (PWH). We investigated whether decreased rainfall is associated with adverse outcomes among PWH on ART in Southern Africa.

METHODS

Data were combined from 11 clinical cohorts of PWH in Lesotho, Malawi, Mozambique, South Africa, Zambia, and Zimbabwe, participating in the International epidemiology Databases to Evaluate AIDS Southern Africa (IeDEA-SA) collaboration. Adult PWH who had started ART prior to 01/06/2016 and were in follow-up in the year prior to 01/06/2016 were included. Two-year rainfall from June 2014 to May 2016 at the location of each HIV centre was summed and ranked against historical 2-year rainfall amounts (1981-2016) to give an empirical relative percentile rainfall estimate. The IeDEA-SA and rainfall data were combined using each HIV centre's latitude/longitude. In individual-level analyses, multivariable Cox or generalized estimating equation regression models (GEEs) assessed associations between decreased rainfall versus historical levels and four separate outcomes (mortality, CD4 counts < 200 cells/mm3, viral loads > 400 copies/mL, and > 12-month gaps in follow-up) in the two years following the rainfall period. GEEs were used to investigate the association between relative rainfall and monthly numbers of unique visitors per HIV centre.

RESULTS

Among 270,708 PWH across 386 HIV centres (67% female, median age 39 [IQR: 32-46]), lower rainfall than usual was associated with higher mortality (adjusted Hazard Ratio: 1.18 [95%CI: 1.07-1.32] per 10 percentile rainfall rank decrease) and unsuppressed viral loads (adjusted Odds Ratio: 1.05 [1.01-1.09]). Levels of rainfall were not strongly associated with CD4 counts < 200 cell/mm3 or > 12-month gaps in care. HIV centres in areas with less rainfall than usual had lower numbers of PWH visiting them (adjusted Rate Ratio: 0.80 [0.66-0.98] per 10 percentile rainfall rank decrease).

CONCLUSIONS

Decreased rainfall could negatively impact on HIV treatment behaviours and outcomes. Further research is needed to explore the reasons for these effects. Interventions to mitigate the health impact of severe weather events are required.

Long-term hepatitis B and liver outcomes among adults taking tenofovir-containing antiretroviral therapy for HBV/HIV coinfection in Zambia

BACKGROUND

Long-term outcomes of tenofovir-containing antiretroviral therapy (ART) for HBV/HIV coinfection were evaluated in Zambia.

METHODS

A prospective cohort of adults with HIV and hepatitis B surface antigen (HBsAg)-positivity was enrolled at ART (included tenofovir DF + lamivudine) initiation. On therapy, we ascertained HBV viral load (VL) non-suppression, ALT elevation, serologic end-points, progression of liver fibrosis, based on elastography, and hepatocellular carcinoma (HCC) incidence. We also described a subgroup (low HBV VL and no/minimal fibrosis at baseline) that, under current international guidelines, would not have been treated in the absence of their HIV infection.

RESULTS

Among 289 participants, at ART start, median age was 34 years, 40·1% were women, median CD4 count was 191 cells/mm3, 44·2% were hepatitis B e antigen-positive, and 28·4% had liver fibrosis/cirrhosis. Over median 5.91 years of ART, 13·6% developed HBV viral non-suppression, which was associated with advanced HIV disease. ALT elevation on ART was linked with HBV VL non-suppression. Regression of fibrosis and cirrhosis were common, progression to cirrhosis was absent, and no cases of HCC were ascertained. HBsAg seroclearance was 9·4% at 2 and 15·4% at 5 years, with higher rates among patients with low baseline HBV replication markers.

DISCUSSION

Reassuring long-term liver outcomes were ascertained during tenofovir-based ART for HBV/HIV coinfection in Zambia. Higher than expected HBsAg seroclearance during ART underscores the need to include people with HIV in HBV cure research.

Association of biomarkers of enteric dysfunction, systemic inflammation, and growth hormone resistance with seroconversion to oral rotavirus vaccine: A lasso for inference approach

BACKGROUND

Rotavirus gastroenteritis remains a leading cause of morbidity and mortality despite the introduction of vaccines. Research shows there are several factors contributing to the reduced efficacy of rotavirus vaccines in low- and middle-income settings. Proposed factors include environmental enteric dysfunction (EED), malnutrition, and immune dysfunction. This study aimed to assess the effect of these factors on vaccine responses using a machine learning lasso approach.

METHODS

Serum samples from two rotavirus clinical trials (CVIA 066 n = 99 and CVIA 061 n = 124) were assessed for 11 analytes using the novel Micronutrient and EED Assessment Tool (MEEDAT) multiplex ELISA. Immune responses to oral rotavirus vaccines (Rotarix, Rotavac, and Rotavac 5D) as well as a parenteral rotavirus vaccine (trivalent P2-VP8) were also measured and machine learning using the lasso approach was then applied to investigate any associations between immune responses and environmental enteric dysfunction, systemic inflammation, and growth hormone resistance biomarkers.

RESULTS

Both oral and parenteral rotavirus vaccine responses were negatively associated with retinol binding protein 4 (RBP4), albeit only weakly for oral vaccines. The parenteral vaccine responses were positively associated with thyroglobulin (Tg) and histidine-rich protein 2 (HRP2) for all three serotypes (P8, P6 and P4), whilst intestinal fatty acid binding protein (I-FABP) was negatively associated with P6 and P4, but not P8, and soluble transferrin receptor (sTfR) was positively associated with P6 only.

CONCLUSION

MEEDAT successfully measured biomarkers of growth, systemic inflammation, and EED in infants undergoing vaccination, with RBP4 being the only analyte associated with both oral and parenteral rotavirus vaccine responses. Tg and HRP2 were associated with responses to all three serotypes in the parenteral vaccine, while I-FABP and sTfR results indicated possible strain specific immune responses to parenteral immunization.

Prevalence of Diarrhoeagenic Escherichia coli among Children Aged between 0-36 Months in Peri-Urban Areas of Lusaka

Diarrhoea is a major contributor to childhood morbidity and mortality in developing countries, with diarrhoeagenic Escherichia coli being among the top aetiological agents. We sought to investigate the burden and describe the diarrhoeagenic E. coli pathotypes causing diarrhoea among children in peri-urban areas of Lusaka, Zambia. This was a facility-based surveillance study conducted over an 8-month period from 2020 to 2021. Stool samples were collected from children aged 0-3 years presenting with diarrhoea at five peri-urban health facilities in Lusaka. Stool samples were tested for diarrhoeagenic E. coli using the Novodiag bacterial GE+® panel, a platform utilising real-time PCR and microarray technology to detect bacterial pathogens. Of the 590 samples tested, diarrhoeagenic E. coli were detected in 471 (76.1%). The top three pathogens were enteropathogenic E. coli 45.4% (n = 268), enteroaggregative E. coli 39.5% (n = 233), and enterotoxigenic E. coli 29.7% (n = 176). Our results revealed that 50.1% of the diarrhoeagenic E. coli positive samples comprised multiple pathotypes of varying virulence gene combinations. Our study demonstrates a high prevalence of diarrhoeagenic E. coli in childhood diarrhoea and the early exposure (<12 months) of children to enteric pathogens. This calls for the early implementation of preventive interventions for paediatric diarrhoea.

Hepatitis B viral replication markers and hepatic fibrosis in untreated chronic hepatitis B virus infection with and without HIV coinfection in Zambia

BACKGROUND

To inform novel therapies, a more nuanced understanding of HIV's impact on hepatitis B virus (HBV) natural history is needed, particularly in high burden countries.

METHODS

In Lusaka, Zambia, we compared prospectively recruited adults (18+ years) with chronic HBV infection, with and without HIV. We excluded those with prior antiviral treatment experience or HBV diagnosis due to clinical suspicion (rather than routine testing). We assessed HBV DNA levels, hepatitis B e antigen (HBeAg), CD4 + (if HIV coinfection), and liver disease (transient elastography, serum alanine aminotransferase). In multivariable analyses, we evaluated the association of HIV overall and by level of CD4 + count on these markers.

RESULTS

Among 713 adults analyzed, median age was 33 years, 63% were male, and 433 had HBV/HIV coinfection. Median CD4 + count was 200 cells/μl. HBV DNA was greater than 2000 IU/ml for 311 (51.0%) and 227 (32.5%) were HBeAg-positive. 15.5% had advanced fibrosis or cirrhosis. HIV coinfection was associated with five-fold increased HBV DNA levels [adjusted geometric mean ratio, 5.78; 95% confidence interval (CI), 2.29-14.62] and two times the odds of HBeAg-positivity (adjusted odds ratio, 2.54; 95% CI, 1.59-4.08). These associations were significant only at CD4 + counts 100-350 and <100 cells/μl. HIV was not associated with markers of fibrosis or ALT.

DISCUSSION

HIV's impact on HBV natural history likely depends on the degree and duration of immune suppression. There is strong rationale to monitor HBV DNA in people with HBV/HIV coinfection and immune suppression. A better understanding is needed of mechanisms of increased liver-related mortality in people with HBV/HIV coinfection.

Safety, tolerability, and immunogenicity of an oral inactivated ETEC vaccine (ETVAX®) with dmLT adjuvant in healthy adults and children in Zambia: An age descending randomised, placebo-controlled trial

BACKGROUND

Enterotoxigenic Escherichia coli (ETEC) is an important cause of moderate to severe diarrhoea in children for which there is no licensed vaccine. We evaluated ETVAX®, an oral, inactivated ETEC vaccine containing four E. coli strains over-expressing the major colonization factors CFA/I, CS3, CS5, and CS6, a toxoid (LCTBA) and double mutant heat-labile enterotoxin (dmLT) adjuvant for safety, tolerability, and immunogenicity.

METHODS

A double-blind, placebo-controlled, age-descending, dose-finding trial was undertaken in 40 adults, 60 children aged 10-23 months, and 146 aged 6-9 months. Adults received one full dose of ETVAX® and children received 3 doses of either 1/4 or 1/8 dose. Safety was evaluated as solicited and unsolicited events for 7 days following vaccination. Immunogenicity was assessed by evaluation of plasma IgA antibody responses to CFA/I, CS3, CS5, CS6, and LTB, and IgG responses to LTB.

RESULTS

Solicited adverse events were mostly mild or moderate with only 2 severe fever reports which were unrelated to the vaccine. The most common events were abdominal pain in adults (26.7 % in vaccinees vs 20 % in placebos), and fever in children aged 6-9 months (44 % vs 54  %). Dosage, number of vaccinations and decreasing age had no influence on severity or frequency of adverse events. The vaccine induced plasma IgA and IgG responses against LTB in 100 % of the adults and 80-90 % of the children. In the 6-23 months cohort, IgA responses to more than 3 vaccine antigens after 3 doses determined as ≥2-fold rise was significantly higher for 1/4 dose compared to placebo (56.7 % vs 27.2 %, p = 0.01). In the 6-9 months cohort, responses to the 1/4 dose were significantly higher than 1/8 dose after 3 rather than 2 doses.

CONCLUSION

ETVAX® was safe, tolerable, and immunogenic in Zambian adults and children. The 1/4 dose induced significantly stronger IgA responses and is recommended for evaluation of protection in children.

CLINICAL TRIALS REGISTRATION

The trial is registered with the Pan African Clinical Trials Registry (PACTR Ref. 201905764389804) and a description of this clinical trial is available on: https://pactr.samrc.ac.za/Trial Design.

Intersection of alcohol use, HIV infection, and the HIV care continuum in Zambia: nationally representative survey

Through a nationally-representative household survey, we measured the prevalence and correlates of unhealthy alcohol use (UAU) in Zambia and its association with the HIV care continuum. Adolescent and adult (ages 15-59 years) data, including the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C), from the 2016 Zambia Population-based HIV Impact Assessment, were analyzed. UAU was defined as AUDIT-C of 3 + points for women and 4 + for men. Among 20,923 participants, 15.3% had UAU; this was 21.6% among people living with HIV (PLWH). Male sex, increasing age, being employed, urban residence, and having HIV were independent correlates of UAU (all P < 0.05). Among PLWH, UAU was associated with reduced HIV diagnosis (adjusted odds ratio [AOR]: 0.66, 95% CI 0.50-0.88) and non-significant trends toward reduced ART use if diagnosed (AOR: 0.73, 95% CI 0.73-1.10) and reduced viral suppression (VS) if on ART (AOR: 0.91, 95% CI 0.57-1.44). Overall, UAU was linked to 25% lower odds of VS compared to abstinence. UAU in Zambia disproportionately affects certain groups including PLWH. Achieving and sustaining HIV epidemic control in Zambia will require evidence-based approaches to screen and treat UAU.

Ecological Niche Modeling of Aedes and Culex Mosquitoes: A Risk Map for Chikungunya and West Nile Viruses in Zambia

The circulation of both West Nile Virus (WNV) and Chikungunya Virus (CHIKV) in humans and animals, coupled with a favorable tropical climate for mosquito proliferation in Zambia, call for the need for a better understanding of the ecological and epidemiological factors that govern their transmission dynamics in this region. This study aimed to examine the contribution of climatic variables to the distribution of Culex and Aedes mosquito species, which are potential vectors of CHIKV, WNV, and other arboviruses of public-health concern. Mosquitoes collected from Lusaka as well as from the Central and Southern provinces of Zambia were sorted by species within the Culex and Aedes genera, both of which have the potential to transmit viruses. The MaxEnt software was utilized to predict areas at risk of WNV and CHIKV based on the occurrence data on mosquitoes and environmental covariates. The model predictions show three distinct spatial hotspots, ranging from the high-probability regions to the medium- and low-probability regions. Regions along Lake Kariba, the Kafue River, and the Luangwa Rivers, as well as along the Mumbwa, Chibombo, Kapiri Mposhi, and Mpika districts were predicted to be suitable habitats for both species. The rainfall and temperature extremes were the most contributing variables in the predictive models.

Maternal and Infant Histo-Blood Group Antigen (HBGA) Profiles and Their Influence on Oral Rotavirus Vaccine (RotarixTM) Immunogenicity among Infants in Zambia

Live-attenuated, oral rotavirus vaccines have significantly reduced rotavirus-associated diarrhoea morbidity and infant mortality. However, vaccine immunogenicity is diminished in low-income countries. We investigated whether maternal and infant intrinsic susceptibility to rotavirus infection via histo-blood group antigen (HBGA) profiles influenced rotavirus (ROTARIX®) vaccine-induced responses in Zambia. We studied 135 mother-infant pairs under a rotavirus vaccine clinical trial, with infants aged 6 to 12 weeks at pre-vaccination up to 12 months old. We determined maternal and infant ABO/H, Lewis, and secretor HBGA phenotypes, and infant FUT2 HBGA genotypes. Vaccine immunogenicity was measured as anti-rotavirus IgA antibody titres. Overall, 34 (31.3%) children were seroconverted at 14 weeks, and no statistically significant difference in seroconversion was observed across the various HBGA profiles in early infant life. We also observed a statistically significant difference in rotavirus-IgA titres across infant HBGA profiles at 12 months, though no statistically significant difference was observed between the study arms. There was no association between maternal HBGA profiles and infant vaccine immunogenicity. Overall, infant HBGAs were associated with RV vaccine immunogenicity at 12 months as opposed to in early infant life. Further investigation into the low efficacy of ROTARIX® and appropriate intervention is key to unlocking the full vaccine benefits for U5 children.

Impact of antibiotics on gut microbiome composition and resistome in the first years of life in low- to middle-income countries: A systematic review

BACKGROUND

Inappropriate antimicrobial usage is a key driver of antimicrobial resistance (AMR). Low- and middle-income countries (LMICs) are disproportionately burdened by AMR and young children are especially vulnerable to infections with AMR-bearing pathogens. The impact of antibiotics on the microbiome, selection, persistence, and horizontal spread of AMR genes is insufficiently characterized and understood in children in LMICs. This systematic review aims to collate and evaluate the available literature describing the impact of antibiotics on the infant gut microbiome and resistome in LMICs.

METHODS AND FINDINGS

In this systematic review, we searched the online databases MEDLINE (1946 to 28 January 2023), EMBASE (1947 to 28 January 2023), SCOPUS (1945 to 29 January 2023), WHO Global Index Medicus (searched up to 29 January 2023), and SciELO (searched up to 29 January 2023). A total of 4,369 articles were retrieved across the databases. Duplicates were removed resulting in 2,748 unique articles. Screening by title and abstract excluded 2,666 articles, 92 articles were assessed based on the full text, and 10 studies met the eligibility criteria that included human studies conducted in LMICs among children below the age of 2 that reported gut microbiome composition and/or resistome composition (AMR genes) following antibiotic usage. The included studies were all randomized control trials (RCTs) and were assessed for risk of bias using the Cochrane risk-of-bias for randomized studies tool. Overall, antibiotics reduced gut microbiome diversity and increased antibiotic-specific resistance gene abundance in antibiotic treatment groups as compared to the placebo. The most widely tested antibiotic was azithromycin that decreased the diversity of the gut microbiome and significantly increased macrolide resistance as early as 5 days posttreatment. A major limitation of this study was paucity of available studies that cover this subject area. Specifically, the range of antibiotics assessed did not include the most commonly used antibiotics in LMIC populations.

CONCLUSION

In this study, we observed that antibiotics significantly reduce the diversity and alter the composition of the infant gut microbiome in LMICs, while concomitantly selecting for resistance genes whose persistence can last for months following treatment. Considerable heterogeneity in study methodology, timing and duration of sampling, and sequencing methodology in currently available research limit insights into antibiotic impacts on the microbiome and resistome in children in LMICs. More research is urgently needed to fill this gap in order to better understand whether antibiotic-driven reductions in microbiome diversity and selection of AMR genes place LMIC children at risk for adverse health outcomes, including infections with AMR-bearing pathogens.

Telemedicine for unhealthy alcohol use in adults living with HIV in Alabama using common elements treatment approach: A hybrid clinical efficacy-implementation trial protocol

Background

Unhealthy alcohol use is an unaddressed barrier to achieving and maintaining control of the human immunodeficiency virus (HIV) epidemic. Integrated screening, treatment of common behavioral and mental health comorbidities, and telemedicine can improve alcohol treatment and HIV clinical and quality of life outcomes for rural and underserved populations.

Objective

In a randomized controlled clinical trial, we will evaluate the effectiveness and implementation of telephone-delivered Common Elements Treatment Approach (T-CETA), a transdiagnostic cognitive behavioral therapy protocol, on unhealthy alcohol use, HIV, other substance use and mental health outcomes among predominantly rural adults with HIV receiving care at community clinics in Alabama.

Methods

Adults with HIV receiving care at four selected community clinics in Alabama will receive a telephone-delivered alcohol brief intervention (BI), and then be assigned at random (stratified by clinic and sex) to no further intervention or T-CETA. Participants will be recruited after screening positively for unhealthy alcohol use or when referred by a provider. The target sample size is 308. The primary outcome will be change in the Alcohol Use Disorder Identification Test (AUDIT) at six- and 12-months post-enrollment. Additional outcomes include HIV (retention in care and viral suppression), patient-reported mental health (anxiety, depression, posttraumatic stress), and quality of life. A range of implementation measures be evaluated including T-CETA provider and client acceptability, feasibility, cost and cost-effectiveness.

Conclusions

This trial will inform alcohol treatment within HIV care programs, including the need to consider comorbidities, and the potential impact of alcohol interventions on HIV and quality of life outcomes.

Modeling SARS-CoV-2 antibody seroprevalence and its determinants in Ghana: A nationally representative cross-sectional survey

Estimates of SARS-CoV-2 transmission rates have significant public health policy implications since they shed light on the severity of illness in various groups and aid in strategic deployment of diagnostics, treatment and vaccination. Population-based investigations have not been conducted in Ghana to identify the seroprevalence of SARS-CoV-2. We conducted an age stratified nationally representative household study to determine the seroprevalence of SARS-CoV-2 and identify risk factors between February and December 2021. Study participants, 5 years and older regardless of prior or current infection COVID-19 infection from across Ghana were included in the study. Data on sociodemographic characteristics, contact with an individual with COVID-19-related symptoms, history of COVID-19-related illness, and adherence to infection prevention measures were collected. Serum obtained was tested for total antibodies with the WANTAI ELISA kit. The presence of antibodies against SAR-COV-2 was detected in 3,476 of 5,348 participants, indicating a seroprevalence of 67.10% (95% CI: 63.71-66.26). Males had lower seroprevalence (65.8% [95% CI: 63.5-68.04]) than females (68.4% [95% CI: 66.10-69.92]). Seroprevalence was lowest in >20 years (64.8% [95% CI: 62.36-67.19]) and highest among young adults; 20-39 years (71.1% [95% CI 68.83,73.39]). Seropositivity was associated with education, employment status and geographic location. Vaccination status in the study population was 10%. Exposure is more likely in urban than rural areas thus infection prevention protocols must be encouraged and maintained. Also, promoting vaccination in target groups and in rural areas is necessary to curb transmission of the virus.

Development and validation of a novel scale for antiretroviral therapy readiness among pregnant women in urban Zambia with newly diagnosed HIV infection

BACKGROUND

Women who are newly diagnosed with HIV infection during pregnancy may not be ready to immediately initiate lifelong antiretroviral therapy (ART; called Option B +) as is recommended. Lack of "readiness" drives early disengagement from care and undermines prevention of HIV transmission to infants. Several studies have shown high early attrition of women initiating ART in pregnancy. Although poor ART uptake and adherence have been attributed to various factors including stigma, disclosure issues and structural issues, there is no standard way of determining which pregnant woman will face challenges and therefore need additional support. We developed and validated a novel ART readiness tool in Lusaka, Zambia.

METHODS

The aim of this study was to develop and validate a tool that could be used to assess how ready a newly diagnosed pregnant woman living with HIV would be to initiate ART on the day of diagnosis. Using a mixed method design, we conducted this study in three public-setting health facilities in Lusaka, Zambia. Informed by qualitative research and literature review, we identified 27 candidate items. We assessed content validity using expert and target population judgment approaches. We administered the 27-item questionnaire to 454 newly diagnosed pregnant women living with HIV, who were enrolled into a randomized trial (trials number NCT02459678). We performed item reduction analysis and used Cronbach's alpha coefficient of 0.70 as threshold for reliability.

RESULTS

A total of 454 pregnant women living with HIV enrolled in the study between March 2017 and December 2017; 452 had complete data for analysis. The correlation coefficient between the 27 items on the completed ART readiness scale ranged from 0.31 to 0.70 while item discrimination index ranged from -0.01 to 2.38. Sixteen items were selected for the final scale, representing three domains, which we classified as "internalized and anticipated HIV stigma", "partner support" and "anticipated structural barriers".

CONCLUSION

We developed and validated a tool that could be used to assess readiness of newly diagnosed women living with HIV to initiate ART. This ART readiness tool could allow clinics to tailor limited resources to pregnant women living with HIV needing additional support to initiate and remain on ART.

Sensitivity and predictive value of dysentery in diagnosing shigellosis among under five children in Zambia

BACKGROUND

Shigella is a leading cause of bacterial diarrhea morbidity and mortality affecting mainly children under five in the developing world. In Zambia, Shigella has a high prevalence of 34.7% in children with diarrhea and an attributable fraction of 6.7% in Zambian children with moderate to severe diarrhea. Zambian diarrhea management guidelines and the health ministry reporting tool Health Management Information System (HMIS) heavily rely on the WHO clinical classification of dysentery to potentially identify and estimate the burden of Shigella in children. This reliance on clinical dysentery as a proxy to shigellosis in under five children may be resulting in gross under-estimation of shigella disease burden in Zambia.

METHODS

We used existing laboratory and clinical data to examine the sensitivity and predictive value of dysentery to correctly identify Shigella infection in under five children with PCR confirmed Shigella infection in Lusaka and Ndola districts, Zambia.

RESULTS

Clinical dysentery had a sensitivity of 8.5% (34/401) in identifying under five children with Shigella by stool PCR. Dysentery was able to correctly classify Shigella in 34 of 68 bloody stool samples giving a corresponding positive predictive value of 50%. Of the 1087 with non-bloody diarrhea, 720 did not have Shigella giving a negative predictive value of 66.2%.

CONCLUSIONS

Use of clinical dysentery as a screening symptom for Shigella infection in children under five presenting with moderate to severe diarrhea has low sensitivity and low positive predictive value respectively. Clinical dysentery as a screening symptom for Shigella contributes to gross under diagnosis and reporting of Shigella infection among under five children in Zambia. Further research is required to better inform practice on more accurate methods or tools to use in support of routine diagnosis, particularly in low middle-income settings where laboratory diagnosis remains a challenge.

Burden of chronic kidney diseases and underlying causes in Zambia: evidence from the global burden of disease study 2019

INTRODUCTION

Chronic kidney disease (CKD) has been a global public health problem and a major source of suffering and poor quality of life for those afflicted. Using data from the global burden of disease (GBD) study 2019, we estimated the magnitude of the burden of CKD as well as the underlying causes of CKD in the Zambian population.

METHOD

The data used for this study were extracted from the GBD 2019 study. The GBD 2019 provides estimates of several metrics of disease burden including the commonly used disability-adjusted life year (DALYs) for over 369 diseases and injuries, and 87 risk factors and combinations of these in 204 countries and territories from 1990 to 2019. We estimated the burden of CKD as the number and rates (per 100,000 population) of DALYs, disaggregated by year, sex, and age group. We examined the underlying causes of CKD by estimating the population attributable fraction as the percentage contributions of risk factors to CKD DALY.

RESULTS

The number of DALYs for CKD was estimated as 76.03 million (95% UI: 61.01 to 93.36) in 2019 compared to 39.42 million (95% UI: 33.09 to 45.90) in 1990, representing 93% increase whereas the DALYs rate per 100,000 population was estimated as 416.89 (95% UI: 334.53 to 511.93) in 2019 compared to 496.38 (95% UI: 416.55 to 577.87) in 1990, representing 16% reduction. CKD due to hypertension accounted for 18.7% of CKD DALYs and CKD due to diabetes (types 1 and 2) accounted for 22.7%, while CKD from glomerulonephritis accounted for the most DALYs at 33%. The age group most impacted from CKD were adolescents and young adults.

CONCLUSION

The burden of CKD remains high in the Zambian population with diabetes, high blood pressure, and glomerulonephritis as important causes. The results highlight the need to develop a comprehensive action plan to prevent and treat kidney disease. Increasing the awareness of CKD among the public as well as adaptation of guidelines for treating patients with end stage kidney disease are important considerations.

Alcohol-focused and transdiagnostic treatments for unhealthy alcohol use among adults with HIV in Zambia: A 3-arm randomized controlled trial

BACKGROUND

Clinical and quality of life outcomes in people living with human immunodeficiency virus (PLWH) are undermined by unhealthy alcohol use (UAU), which is highly prevalent in this population and is often complicated by mental health (MH) or other substance use (SU) comorbidity. In sub-Saharan Africa, evidence-based and implementable treatment options for people with HIV and UAU are needed.

METHODS

We are conducting a hybrid clinical effectiveness-implementation trial at three public-sector HIV clinics in Lusaka, Zambia. Adults with HIV, who report UAU, and have suboptimal HIV clinical outcomes, will be randomized to one of three arms: an alcohol-focused brief intervention (BI), the BI with additional referral to a transdiagnostic cognitive behavioral therapy (Common Elements Treatment Approach [CETA]), or standard of care. The BI and CETA will be provided by HIV peer counselors, a common cadre of lay health worker in Zambia. Clinical outcomes will include HIV viral suppression, alcohol use, assessed by audio computer-assisted self-interview (ACASI) and direct alcohol biomarkers, Phophatidylethanol and Ethyl glucuronide, and comorbid MH and other SU. A range of implementation outcomes including cost effectiveness will also be analyzed.

CONCLUSION

Hybrid and 3-arm trial design features facilitate the integrated evaluation of both brief, highly implementable, and more intensive, less implementable, treatment options for UAU among PLWH in sub-Saharan Africa. Use of ACASI and alcohol biomarkers will strengthen understanding of treatment effects.

Assessment of the influence of ABO blood groups on oral cholera vaccine immunogenicity in a cholera endemic area in Zambia

BACKGROUND

Histo-blood group antigens (HBGAs) which include the ABO and Lewis antigen systems have been known for determining predisposition to infections. For instance, blood group O individuals have a higher risk of severe illness due to V. cholerae compared to those with non-blood group O antigens. We set out to determine the influence that these HBGAs have on oral cholera vaccine immunogenicity and seroconversion in individuals residing within a cholera endemic area in Zambia.

METHODOLOGY

We conducted a longitudinal study nested under a clinical trial in which samples from a cohort of 223 adults who were vaccinated with two doses of Shanchol™ and followed up over 4 years were used. We measured serum vibriocidal geometric mean titers (GMTs) at Baseline, Day 28, Months 6, 12, 24, 30, 36 and 48 in response to the vaccine. Saliva obtained at 1 year post vaccination was tested for HBGA phenotypes and secretor status using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Of the 133/223 participants included in the final analysis, the majority were above 34 years old (58%) and of these, 90% were males. Seroconversion rates to V. cholerae O1 Inaba with non-O (23%) and O (30%) blood types were comparable. The same pattern was observed against O1 Ogawa serotype between non-O (25%) and O (35%). This trend continued over the four-year follow-up period. Similarly, no significant differences were observed in seroconversion rates between the non-secretors (26%) and secretors (36%) against V. cholerae O1 Inaba. The same was observed for O1 Ogawa in non-secretors (22%) and the secretors (36%).

CONCLUSION

Our results do not support the idea that ABO blood grouping influence vaccine uptake and responses against cholera.

Integrating isoniazid preventive therapy into the fast-track HIV treatment model in urban Zambia: A proof-of -concept pilot project

Most people living with HIV (PLHIV) established on treatment in Zambia receive multi-month prescribing and dispensing (MMSD) antiretroviral therapy (ART) and are enrolled in less-intensive differentiated service delivery (DSD) models such as Fast Track (FT), where clients collect ART every 3-6 months and make clinical visits every 6 months. In 2019, Zambia introduced Isoniazid Preventive Therapy (IPT) with scheduled visits at 2 weeks and 1, 3, and 6 months. Asynchronous IPT and HIV appointment schedules were inconvenient and not client centered. In response, we piloted integrated MMSD/IPT in FT HIV treatment model. We implemented and evaluated a proof-of-concept project at one purposively selected high-volume facility in Lusaka, Zambia between July 2019 and May 2020. We sensitized stakeholders, adapted training materials, standard operating procedures, and screened adults in FT for TB as per national guidelines. Participants received structured TB/IPT education, 6-month supply of isoniazid and ART, aligned 6th month IPT/MMSD clinic appointment, and phone appointments at 2 weeks and months 1-5 following IPT initiation. We used descriptive statistics to characterize IPT completion rates, phone appointment keeping, side effect frequency and Fisher's exact test to determine variation by participant characteristics. Key lessons learned were synthesized from monthly meeting notes. 1,167 clients were screened with 818 (70.1%) enrolled, two thirds (66%) were female and median age 42 years. 738 (90.2%) completed 6-month IPT course and 66 (8.1%) reported IPT-related side effects. 539 clients (65.9%) attended all 7 telephone appointments. There were insignificant differences of outcomes by age or sex. Lessons learnt included promoting project ownership, client empowerment, securing supply chain, adapting existing processes, and cultivating collaborative structured learning. Integrating multi-month dispensing and telephone follow up of IPT into the FT HIV treatment model is a promising approach to scaling-up TB preventive treatment among PLHIV, although limited by barriers to consistent phone access.

Estimated incidence and transmission intensity of rubella infection in Zambia pre-vaccine era 2005-2016

The rubella disease burden in Zambia may be under-estimated. Using models, we describe the transmission dynamics, determine the incidence estimates and assess the level of underestimation of the real burden of rubella infection in Zambia during the pre-vaccination period 2005-2016. This study used both the deterministic compartmental model and likelihood-based method using a Bayesian framework to describe the epidemiology of rubella. A total of 1313 cases of rubella were confirmed with the highest annual number of 255 new cases recorded in 2008. However, 2014 recorded the highest monthly median positivity rate of 9.0%. The observed median rubella cases were 5.5. There was a seasonal pattern in the occurrence of laboratory-confirmed rubella, with higher test positivity rates of rubella infection usually recorded in the months of September, October and November. The modelled monthly median incidence of rubella infection among the general population was 76 and 20 among pregnant women. The incidence of rubella among the non-pregnant women was 44. The average effective reproductive number (Rt) between 2005 and 2016 was estimated as 1.2 with the peak of infection occurring in 2016. The measles surveillance system underestimates the observed burden of rubella. A mass vaccination campaign conducted between January and July is recommended.

Metabolic syndrome among treatment-naïve people living with and without HIV in Zambia and Zimbabwe: a cross-sectional analysis

INTRODUCTION

Chronic viral replication has been linked to an increased risk of cardiovascular and metabolic diseases in people living with HIV (PLWH), but few studies have evaluated this association in Southern Africa. We explored the determinants of metabolic syndrome (MetS) among treatment-naïve adults living with and without HIV in Southern Africa.

METHODS

Treatment-naïve PLWH and people living without HIV (PLWOH) ≥30 years were consecutively enrolled from primary care clinics in Zambia and Zimbabwe. PLWOH were seronegative partners or persons presenting for HIV testing. We defined MetS as the presence of central obesity plus any two of the following: raised blood pressure, impaired fasting glucose, reduced high-density lipoprotein cholesterol and raised triglycerides, as defined by the International Diabetes Federation. We used logistic regression to determine factors associated with MetS.

RESULTS

Between August 2019 and March 2022, we screened 1285 adults and enrolled 420 (47%) PLWH and 481 (53%) PLWOH. The median age was similar between PLWH and PLWOH (40 vs. 38 years, p < 0.24). In PLWH, the median CD4⁺ count was 228 cells/mm³ (IQR 108-412) and the viral load was 24,114 copies/ml (IQR 277-214,271). Central obesity was present in 365/523 (70%) females and 57/378 males (15%). MetS was diagnosed in 172/901 (19%, 95% confidence interval [CI] 17-22%), and prevalence was higher among females than males (27% vs. 9%). In multivariable analyses, HIV status was not associated with MetS (adjusted odds ratio [aOR] 1.05, 95% CI 0.74-1.51). Risk factors for MetS included age older than 50 years (aOR 2.31, 95% CI 1.49-3.59), female sex (aOR 3.47, 95% CI 2.15-5.60), highest income (aOR 2.19, 95% CI 1.39-3.44) and less than World Health Organization recommended weekly physical activity (aOR 3.35, 95% CI 1.41-7.96).

CONCLUSIONS

We report a high prevalence of MetS and central obesity among females in urban Zambia and Zimbabwe. Lifestyle factors and older age appear to be the strongest predictors of MetS in our population, with no evident difference in MetS prevalence between treatment-naïve PLWH and PLWOH.

Development of a diarrhoea severity scoring scale in a passive health facility-based surveillance system

Background

Diarrhoeal disease remains a leading cause of death among children mostly in low and middle-income countries. Factors contributing to disease severity are complex and there is currently no consensus on a scoring tool for use in community-based studies.

Methods

Data were collected during a passive surveillance system in an outpatient health facility in Lusaka, Zambia from March 2019 to July 2019. Diarrhea episodes were assessed for severity using an in-house severity scoring tool (CIDRZ) and previously published scores (Vesikari, Clark, CODA, and DHAKA). The CIDRZ score was constructed using fieldworker-reported clinical signs and exploratory factor analysis. We used precision-recall curves measuring severe diarrhoea (i.e., requiring intravenous rehydration or referred for hospital admission) to determine the best performing scores. Then, we used Cronbach’s alpha to assess the scale’s internal consistency. Finally, we used Cohen’s kappa to assess agreement between the scores.

Results

Of 110 diarrhea episodes, 3 (3%) required intravenous rehydration or were referred for hospital admission. The precision-recall area under the curve of each score as a predictor of severe diarrhoea requiring intravenous rehydration or hospital admission was 0.26 for Vesikari, 0.18 for CODA, 0.24 for Clark, 0.59 for DHAKA, and 0.59 for CIDRZ. The CIDRZ scale had substantial reliability and performed similarly to the DHAKA score.

Conclusions

Diarrhoea severity scores focused on characteristics specific to dehydration status may better predict severe diarrhea among children in Lusaka. Aetiology-specific scoring tools may not be appropriate for use in community healthcare settings. Validation studies for the CIDRZ score in diverse settings and with larger sample sizes are warranted.

Liver steatosis and metabolic dysfunction-associated fatty liver disease among HIV-positive and negative adults in urban Zambia

INTRODUCTION

The growing importance of non-communicable diseases (NCDs) and high HIV prevalence in urban African settings may increase the burden of metabolic dysfunction-associated fatty liver disease (MAFLD). We assessed liver steatosis among HIV-positive and negative adults in urban Zambia.

METHODS

Adults 30 years and older who were newly diagnosed with HIV, or tested HIV-negative at two primary care clinics in Lusaka, Zambia, were assessed for liver steatosis. Cardiometabolic data were collected through comprehensive clinical and laboratory assessments. Transient elastography was performed to measure controlled-attenuation parameter (≥248 dB/m). We used multivariable logistic regression models to determine the factors associated with the presence of steatosis.

RESULTS

We enrolled 381 patients, including 154 (40%) antiretroviral therapy-naïve people living with HIV (PLWH) with a median CD4+ count of 247 cells/mm³ and a mean body mass index (BMI) of 23.8 kg/m². Liver steatosis was observed in 10% of participants overall and was more common among HIV-negative adults than in PLWH (15% vs 3%). The proportion of patients with steatosis was 25% among obese (BMI ≥30 kg/m²) participants, 12% among those overweight (BMI 25-29.9 kg/m²), and 7% among those with a BMI <25 kg/m². Among patients with a fasting glucose ≥7 mmol/L or confirmed diabetes, 57% had liver steatosis. In multivariable analyses, HIV status (adjusted odds ratio (aOR) 0.18, 95% CI 0.06 to 0.53), confirmed diabetes or elevated fasting glucose (aOR 3.92, 95% CI 1.57 to 9.78) and elevated blood pressure (aOR 2.95, 95% CI 1.34 to 6.48) were associated with steatosis. The association between BMI>25 kg/m² and liver steatosis was attenuated after adjustment for potential confounders (aOR 1.96, 95% CI 0.88-4.40). Overall, 21 (9%) participants without HIV and 4 (3%) with HIV met the criteria for MAFLD. Among individuals with liver steatosis, 65% (95% CI 49% to 80%) fulfilled criteria of MAFLD, whereas 15 (39%) of them had elevated transaminases and 3 (8%) F2-F4 fibrosis.

CONCLUSIONS

The prevalence of liver steatosis in this urban cohort of HIV-positive and negative adults in Zambia was low, despite a large proportion of patients with high BMI and central obesity. Our study is among the first to report data on MAFLD among adults in Africa, demonstrating that metabolic risk factors are key drivers of liver steatosis and supporting the adoption of the criteria for MAFLD in African populations.

Impact of insecticide-treated nets and indoor residual spraying on self-reported malaria prevalence among women of reproductive age in Ghana: implication for malaria control and elimination

Background

The Global Fund alone contributed 56% of all international financing for malaria and has invested more than US$13.5 billion in malaria treatment, prevention, and control programmes by June 2021. These investments include interventions such as mosquito nets, indoor residual spraying, and preventive treatment for children and pregnant women. However, there is paucity of studies for assessment of such investments to a reduction in malaria prevalence. This study was aimed at quantifying the impact of household access to insecticide-treated nets (ITNs) and the indoor residual spraying (IRS) on self-reported malaria prevalence among women of reproductive age in Ghana.

Methods

The study analysed the 2016 Ghana Malaria Indicator Survey (MIS) data. The MIS is a nationwide survey that included women aged 15–49 years. Poisson regression model with inverse probability to treatment weighting was used to determine average treatment effect estimate of the two malaria interventions on self-reported malaria prevalence among women of reproductive age in Ghana.

Results

A total sample of 4861 women interviewed from the 2016 Ghana MIS was used for analysis. The prevalence of self-reported malaria in 2016 was 34.4% (95% CI [32.4%, 36.4%]). Approximately 80.0% of women lived in households with access to ITNs [Percentage (Pr) = 79.9%, (95% CI [78.0%, 81.7%])], 12.4% (95% CI [7.5%, 19.8%]) of the households had access to IRS and 11.4% (95% CI [7.0%, 18.0%]) of the households had access to both ITNs and IRS. Household access to only ITN contributed to 7.1 percentage point (pt) reduction in the self-reported malaria among women (95% CI [− 12.0%, − 2.1%], p = 0.005) whilst IRS at the households contributed to 6.8pt reduction in malaria prevalence (95% CI [− 12.0%, − 2.1%], p = 0.005). Households with access to both ITNs and IRS contributed to a 27.1pt reduction in self-reported malaria prevalence among women (95% CI [− 12.0%, − 2.1%], p = 0.005).

Conclusion

Access to both ITNs and application of IRS at the household level contributed to a significant reduction in self-reported malaria prevalence among women of reproductive age in Ghana. This finding confirms the need for integration of malaria control interventions to facilitate attainment of malaria elimination in Ghana.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04136-3.

Efficacy of the Common Elements Treatment Approach (CETA) for Unhealthy Alcohol Use Among Adults with HIV in Zambia: Results from a Pilot Randomized Controlled Trial

This randomized controlled trial tested the efficacy of a multi-session, evidence-based, lay counselor-delivered transdiagnostic therapy, the Common Elements Treatment Approach (CETA), in reducing unhealthy alcohol use and comorbidities among persons living with HIV (PLWH) in Zambia. Adult PLWH with (a) unhealthy alcohol use plus mental health or substance use comorbidities, or (b) severe unhealthy alcohol use were randomized to receive a single-session alcohol brief intervention (BI) alone or BI plus referral to CETA. Outcomes were measured at baseline and a 6-month follow-up and included Alcohol Use Disorders Identification Test (AUDIT) score (primary), depression and trauma symptoms, and other substance use (secondary). We enrolled 160 participants; 78 were randomized to BI alone and 82 to BI plus CETA. Due to COVID-19, the trial ended early before 36 participants completed. Statistically and clinically significant reductions in mean AUDIT score from baseline to 6-month follow-up were observed in both groups, however, participants assigned to BI plus CETA had significantly greater reductions compared to BI alone (− 3.2, 95% CI − 6.2 to − 0.1; Cohen’s d: 0.48). The CETA effect size for AUDIT score increased in line with increasing mental health/substance use comorbidity (0 comorbidities d = 0.25; 1–2 comorbidities d = 0.36; 3+ comorbidities d = 1.6). Significant CETA treatment effects were observed for depression, trauma, and several other substances. BI plus referral to CETA was feasible and superior to BI alone for unhealthy alcohol use among adults with HIV, particularly among those with comorbidities. Findings support future effectiveness testing of CETA for HIV outcomes among PLWH with unhealthy alcohol use.

Clinical Trials Number: NCT03966885

Immunogenicity and waning immunity from the oral cholera vaccine (Shanchol™) in adults residing in Lukanga Swamps of Zambia

Introduction

In cholera endemic areas, the periodicity of cholera outbreaks remains unpredictable, making it difficult to organize preventive efforts. Lack of data on duration of protection conferred by oral cholera vaccines further makes it difficult to determine when to deploy preemptive vaccination. We report on the immunogenicity and waning of immunity to Shanchol^™ in Lukanga Swamps.

Methods

We enrolled a cohort of 223 participants aged between 18 and 65 years old from whom serum samples were collected at baseline, day 28 before administration of the second dose, and consecutively at 6, 12, 24, 30, 36, and 48 months. Vibriocidal antibody titres were measured and expressed as geometric mean titres. Box plots and 95% CI were computed at each visit for both Inaba and Ogawa. Seroconversion was defined as a four fold or greater increase in antibody titres compared to baseline titres.

Results

Overall, seroconversion against V. cholerae Inaba and Ogawa after 1st dose was 35/134 (26%) and 34/134 (25%) respectively. We observed a statistical difference in seroconversion between the two subgroups of baseline titres (low <80 and high ≥80) for both Inaba (p = 0.02) and Ogawa (p<0.0001). From a baseline of 13.58, anti-Ogawa GMT increased to 21.95 after the first dose, but rapidly waned to 14.52, 13.13, and 12.78 at months 6, 12 and 24 respectively, and then increased to 13.21, 18.67 and 23.65 at months 30, 36 and 48 respectively. A similar trend was observed for anti-Inaba GMT across the same time points.

Conclusion

We found that Shanchol^™ was immunogenic in our study population and that vibriocidal antibodies may not be a good marker for long-term immunity. The observed rise in titres after 36 months suggests natural exposure, and this may be a critical time window opening for natural transmission in an endemic areas. We recommend re-vaccination at this time point in high risk areas.

Comparing growth velocity of HIV exposed and non-exposed infants: An observational study of infants enrolled in a randomized control trial in Zambia

BACKGROUND

Impaired growth among infants remains one of the leading nutrition problems globally. In this study, we aimed to compare the growth trajectory rate and evaluate growth trajectory characteristics among children, who are HIV exposed uninfected (HEU) and HIV unexposed uninfected (HUU), under two years in Zambia.

METHOD

Our study used data from the ROVAS II study (PACTR201804003096919), an open-label randomized control trial of two verses three doses of live, attenuated, oral RotarixTM administered 6 &10 weeks or at 6 &10 weeks plus an additional dose at 9 months of age, conducted at George clinic in Lusaka, Zambia. Anthropometric measurements (height and weight) were collected on all scheduled and unscheduled visits. We defined linear growth velocity as the rate of change in height and estimated linear growth velocity as the first derivative of the mixed effect model with fractional polynomial transformations and, thereafter, used the second derivative test to determine the peak height and age at peak heigh.

RESULTS

We included 212 infants in this study with median age 6 (IQR: 6-6) weeks of age. Of these 97 (45.3%) were female, 35 (16.4%) were stunted, and 59 (27.6%) were exposed to HIV at baseline. Growth velocity was consistently below the 3rd percentile of the WHO linear growth standard for HEU and HUU children. The peak height and age at peak height among HEU children were 74.7 cm (95% CI = 73.9-75.5) and 15.5 months (95% CI = 14.7-16.3) respectively and those for HUU were 73 cm (95% CI = 72.1-74.0) and 15.6 months (95% CI = 14.5-16.6) respectively.

CONCLUSION

We found no difference in growth trajectories between infants who are HEU and HUU. However, the data suggests that poor linear growth is universal and profound in this cohort and may have already occurred in utero.

Mosquito-Borne Viral Pathogens Detected in Zambia: A Systematic Review

Emerging and re-emerging mosquito-borne viral diseases are a threat to global health. This systematic review aimed to investigate the available evidence of mosquito-borne viral pathogens reported in Zambia. A search of literature was conducted in PubMed and Google Scholar for articles published from 1 January 1930 to 30 June 2020 using a combination of keywords. Eight mosquito-borne viruses belonging to three families, Togaviridae, Flaviviridae and Phenuiviridae were reported. Three viruses (Chikungunya virus, Mayaro virus, Mwinilunga virus) were reported among the togaviruses whilst four (dengue virus, West Nile virus, yellow fever virus, Zika virus) were among the flavivirus and only one virus, Rift Valley fever virus, was reported in the Phenuiviridae family. The majority of these mosquito-borne viruses were reported in Western and North-Western provinces. Aedes and Culex species were the main mosquito-borne viral vectors reported. Farming, fishing, movement of people and rain patterns were among factors associated with mosquito-borne viral infection in Zambia. Better diagnostic methods, such as the use of molecular tools, to detect the viruses in potential vectors, humans, and animals, including the recognition of arboviral risk zones and how the viruses circulate, are important for improved surveillance and design of effective prevention and control measures.

Serum vibriocidal responses when second doses of oral cholera vaccine are delayed 6 months in Zambia

Two-dose killed oral cholera vaccines (OCV) are currently being used widely to control cholera. The standard dose-interval for OCV is 2 weeks; however, during emergency use of the vaccine, it may be more appropriate to use the available doses to quickly give a single dose to more people and give a delayed second dose when more vaccine becomes available. This study is an open label, randomized, phase 2 clinical trial of the vibriocidal response induced by OCV, comparing the responses when the second dose was given either 2 weeks (standard dose interval) or 6 months (extended dose interval) after the first dose. Vaccine was administered to healthy participants > 1 year of age living in the Lukanga Swamps area of Zambia. Three age cohorts (<5 years, 5-14 years, and ≥ 15 years) were randomized to the either dose-interval. The primary outcome was the vibriocidal GMT 14 days after the second dose. 156 of 172 subjects enrolled in the study were included in this analysis. The Inaba vibriocidal titers were not significantly different 14 days post dose two for a standard dose-interval GMT: 45.6 (32-64.9), as compared to the GMT 47.6 (32.6-69.3), for the extended dose-interval, (p = 0.87). However, the Ogawa vibriocidal GMTs were significantly higher 14 days post dose two for the extended-dose interval at 87.6 (58.9-130.4) compared to the standard dose-interval group at 49.7 (34.1-72.3), p = 0.04. Vibriocidal seroconversion rates (a > 4-fold rise in vibriocidal titer) were not significantly different between dose-interval groups. This study demonstrated that vibriocidal titers 14 days after a second dose when given at an extended\ dose interval were similar to the standard dose-interval. The findings suggest that a flexible dosing schedule may be considered when epidemiologically appropriate. The trial was registered at Clinical Trials.gov (NCT03373669).

Shigella-specific antibodies in the first year of life among Zambian infants: A longitudinal cohort study

Introduction

Shigellosis, is a leading cause of moderate-to-severe diarrhoea and related mortality in young children in low and middle income countries (LMICs). Knowledge on naturally acquired immunity can support the development of Shigella candidate vaccines mostly needed in LMICs. We aimed to quantify Shigella-specific antibodies of maternal origin and those naturally acquired in Zambian infants.

Methods

Plasma samples collected from infants at age 6, 14 and 52-weeks were tested for Shigella (S. sonnei and S. flexneri 2a) lipopolysaccharide (LPS) antigen specific immunoglobulin G (IgG) and A (IgA) by enzyme-linked immunosorbent assay.

Results

At 6 weeks infant age, the IgG geometric mean titres (GMT) against S. sonnei (N = 159) and S. flexneri 2a (N = 135) LPS were 311 (95% CI 259–372) and 446 (95% CI 343–580) respectively. By 14 weeks, a decline in IgG GMT was observed for both S. sonnei to 104 (95% CI 88–124), and S. flexneri 2a to 183 (95% CI 147–230). Both S. sonnei and S. flexneri 2a specific IgG GMT continued to decrease by 52 weeks infant age when compared to 6 weeks. In 27% and 8% of infants a significant rise in titre (4 fold and greater) against S. flexneri 2a and S. sonnei LPS, respectively, was detected between the ages of 14 and 52 weeks.

IgA levels against both species LPS were very low at 6 and 14 weeks and raised significantly against S. flexneri 2a and S. sonnei LPS in 29% and 10% of the infants, respectively.

Conclusion

In our setting, transplacental IgG anti-Shigella LPS is present at high levels in early infancy, and begins to decrease by age 14 weeks. Our results are consistent with early exposure to Shigella and indicate naturally acquired IgG and IgA antibodies to S. flexneri 2a and S. sonnei LPS in part of infants between 14 and 52 weeks of age. These results suggest that a potential timing of vaccination would be after 14 and before 52 weeks of age to ensure early infant protection against shigellosis.

Comparable exposure to SARS-CoV-2 in young children and healthcare workers in Zambia

Background: Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an ongoing global health crisis that has caused large scale morbidity and mortality. We aimed to determine the exposure to SARS-CoV-2 among young children and healthcare workers by measurement of anti-S1 antigen (spike protein) specific immunoglobulin G (IgG) using an in-house optimized indirect enzyme-linked immunosorbent assay (ELISA) method. Methods: Plasma samples were collected from cohorts of healthcare workers (n = 287) and young children aged from 6 weeks to 2 years old (n = 150) pre-COVID-19 pandemic between September 2018 and November 2019 and post-COVID-19 pandemic between August and December 2020 were simultaneously tested for anti-SARS-CoV-2 S1 specific IgG. The arithmetic mean of natural logarithm-transformed ELISA relative absorbance reading + (3 x standard deviation) of pre-pandemic plasma was used as the cut-off to determine SARS-CoV-2 IgG seropositivity of post-pandemic plasma. Results: There was no reactivity to SARS-CoV-2 S1 antigen detected in pre-pandemic plasma but in post pandemic plasma an 8.0% (23/287) IgG seropositivity in healthcare workers’ and 6.0% (9/150) seropositivity in children aged 2 years old was detected. Conclusions: Comparable levels of SARS-CoV-2 IgG seropositivity in healthcare workers and children suggest widespread exposure to SARS-CoV-2 in Zambia during the first wave of the pandemic. This finding has implications for continued acquisition and transmission of infection in the healthcare setting, household, and wider community.

Effect of Enhanced Adherence Package on Early ART Uptake Among HIV-Positive Pregnant Women in Zambia: An Individual Randomized Controlled Trial

We evaluated the effect of an option B-plus Enhanced Adherence Package (BEAP), on early ART uptake in a randomized controlled trial. HIV-positive, ART naïve pregnant women in Lusaka, Zambia, were randomized to receive BEAP (phone calls/home visits, additional counseling, male partner engagement and missed-visit follow-up) versus standard of care (SOC). The primary outcome was initiating and remaining on ART at 30 days. Analysis was by intention to treat (ITT) using logistic regression. Additional per protocol analysis was done. We enrolled 454 women; 229 randomized to BEAP and 225 to SOC. Within 30 days of eligibility, 445 (98.2%) initiated ART. In ITT analysis, 82.5% BEAP versus 80.4% SOC participants reached primary outcome (crude relative risk [RR] 1.03; 95% confidence interval [CI] 0.91-1.16; Wald test statistic = 0.44; p-value = 0.66). In per protocol analysis, (92 participants (40.2%) excluded), 91.9% BEAP versus 80.4% SOC participants reached primary outcome (crude RR 1.14; 95% CI 1.02-1.29; Wald test statistic = 2.23; p-value = 0.03). Early ART initiation in pregnancy was nearly universal but there was early drop out suggesting need for additional adherence support.This trial was registered at ClinicalTrials.gov (trials number NCT02459678) on May 14, 2015.

Mathematical modeling of COVID-19 infection dynamics in Ghana: Impact evaluation of integrated government and individual level interventions

The raging COVID-19 pandemic is arguably the most important threat to global health presently. Although there Although there is currently a a a vaccine, preventive measures have been proposed to reduce the spread of infection but the efficacy of these interventions, and their likely impact on the number of COVID-19 infections is unknown. In this study, we proposed the SEIQHRS model (susceptible-exposed-infectious-quarantine-hospitalized-recovered-susceptible) model that predicts the trajectory of the epidemic to help plan an effective control strategy for COVID-19 in Ghana. We provided a short-term forecast of the early phase of the epidemic trajectory in Ghana using the generalized growth model. We estimated the effective basic Reproductive number Re in real-time using three different estimation procedures and simulated worse case epidemic scenarios and the impact of integrated individual and government interventions on the epidemic in the long term using compartmental models. The maximum likelihood estimates of Re and the corresponding 95% confidence interval was 2.04 [95% CI: 1.82-2.27; 12th March-7th April 2020]. The Re estimate using the exponential growth method was 2.11 [95% CI: 2.00-2.24] within the same period. The Re estimate using time-dependent (TD) method showed a gradual decline of the Effective Reproductive Number since March 12, 2020 when the first 2 index cases were recorded but the rate of transmission remains high (TD: Re = 2.52; 95% CI: [1.87-3.49]). The current estimate of Re based on the TD method is 1.74 [95% CI: 1.41-2.10; (13th May 2020)] but with comprehensive integrated government and individual level interventions, the Re could reduce to 0.5 which is an indication of the epidemic dying out in the general population. Our results showed that enhanced government and individual-level interventions and the intensity of media coverage could have a substantial effect on suppressing transmission of new COVID-19 cases and reduced death rates in Ghana until such a time that a potent vaccine or drug is discovered.

In-vitro inhibitory effect of maternal breastmilk components on rotavirus vaccine replication and association with infant seroconversion to live oral rotavirus vaccine

BACKGROUND

Despite contributing to a significant reduction in rotavirus associated diarrhoea in highly burdened low- and middle-income countries, live attenuated, oral rotavirus vaccines have lower immunogenicity and efficacy in these settings in comparison to more developed countries. Breastmilk has been implicated among factors contributing to this lowered oral vaccine efficacy. We conducted in-vitro experiments to investigate the inhibitory effects of maternal antibody and other non-antibody components in breastmilk on rotavirus vaccine strain (Rotarix) multiplication in MA104 cell culture system and assessed associations with in-vivo vaccine seroconversion in vaccinated infants.

METHODS

Breastmilk samples were collected from mothers before routine rotavirus vaccination of their infant at 6 weeks of age. For each sample, whole breastmilk, purified IgA, purified IgG and IgG and IgA depleted breastmilk samples were prepared as exposure preparations. A 96 well microtitre plate was set up for each sample including a control in which only MA104 cells were grown as well as a virus control with MA104 cells and virus only. The outcome of interest was 50% inhibition dilution of each of the exposure preparations calculated as the titer at which 50% of virus dilution was achieved. Samples from 30 women were tested and correlated to vaccine seroconversion status of the infant. HIV status was also correlated to antiviral breastmilk proteins.

RESULTS

The mean 50% inhibitory dilution titer when whole breastmilk was added to virus infected MA104 cells was 14.3 (95% CI: 7.1, 22.7). Incubation with purified IgG resulted in a mean 50% inhibitory dilution of 5 (95%CI -1.6, 11.6). Incubating with purified IgA resulted in a mean 50% inhibitory dilution of 6.5 (95% CI -0.7, 13.7) and IgG and IgA depleted breastmilk did not yield any inhibition with a titer of 1.06 (95%CI 0.9, 1.2). Higher milk IgA levels contributed to a failure of infants to seroconvert. HIV was also not associated with any antiviral breastmilk proteins.

DISCUSSION AND CONCLUSION

Whole breastmilk and breastmilk purified IgG and IgA fractions showed inhibitory activity against the rotavirus vaccine Rotarix™ whilst IgA and IgG depleted breastmilk with non-antibody breastmilk fraction failed to show any inhibition activity in-vitro. These findings suggest that IgA and IgG may have functional inhibitory properties and indicates a possible mechanism of how mothers in rotavirus endemic areas with high titres of IgA and IgG may inhibit viral multiplication in the infant gut and would potentially contribute to the failure of their infants to serocovert. There was not association of HIV with either lactoferrin, lactadherin or tenascin-C concentrations.

A pilot study on use of live attenuated rotavirus vaccine (Rotarix™) as an infection challenge model

BACKGROUND

Rotavirus remains the commonest cause of dehydrating diarrhoea, particularly in developing countries. Human infection challenge studies in children in these countries offers an opportunity to rapidly evaluate new vaccine candidates that may have improved efficacy. We evaluated use of Rotarix™ as a live-attenuated challenge agent.

METHODS

We undertook an open label, exploratory study in infants receiving two standard doses of Rotarix™ at 6 and 10 weeks of age in a cohort of 22 Zambian infants. The first vaccine dose was considered as primary vaccination, and the second at day 28 as a live-attenuated virus challenge. Saliva, stool and serum samples were collected on days 0, 3, 5, 7, 14, and 28 following each dose. The primary outcome was stool shedding of rotavirus, determined by NSP2 qPCR. We calculated mean shedding index as average of natural logarithm of viral copies per gram of stool.

FINDINGS

After the first dose, viral shedding was high at day 3, peaked by day 5. After the second dose, viral shedding at day 3 was low and reduced gradually in most infants until day 14. Mean shedding index was significantly lower post dose 2 across all infants and timepoints (5.0 virus copies/g of stool [95%CI: 0.3-9.7] vs 10.4 virus copies/g of stool [95%CI: 6.2-14.6]; p-value < 0.0001; rho = 0.20, SD = 4.97. Seroconversion at day 28 was associated with a mean reduction of -1.03 (95%CI = -8.07, 6.01) in viral shedding after challenge dose but this was not statistically significant (p = 0.774). A borderline positive correlation between fold-change in IgA titre at day 28 from day 0 in saliva and serum was observed; Spearman's correlation coefficient, r = 0.69; p = 0.086.

INTERPRETATION

Shedding after the 'challenge' dose was reduced compared with the first dose, consistent with the induction of mucosal immunity by the first dose. This supports the use of Rotarix vaccine as a live-attenuated infection challenge.

FUNDING

Medical Research Council (UK) through the HIC-Vac Network.

Nutritional status, environmental enteric dysfunction, and prevalence of rotavirus diarrhoea among children in Zambia

BACKGROUND

Rotavirus is the most common cause of fatal diarrhoeal disease among children under the age of five globally and is responsible for millions of hospitalizations each year. Although nutritional status and environmental enteric dysfunction (EED) are recognized as important predictors of susceptibility to diarrhoeal disease, no research to date has examined the mechanisms by which undernutrition and EED may protect against prevalence of rotavirus infection.

METHODS

We utilized data collected from a study evaluating the effectiveness of Rotarix™ vaccine against severe gastroenteritis among children under the age of 5 in Zambia. The prevalence of malnutrition, wasting, and stunting at the time of study enrollment was calculated using WHO child growth standards. Commercial ELISA kits were used to assess levels of faecal biomarkers for EED: alpha-1-antitrypsin and myeloperoxidase, and calprotectin. Separate multivariate logistic regression models were used to examine each measure of nutritional status and rotavirus diarrhoea including and excluding adjustment for EED.

RESULTS

In models that did not include adjustment for EED, malnourished children had 0.66 times the odds of having rotavirus diarrhoea compared to children with normal nutritional status (95% CI: 0.42, 1.0; p = 0.07). EED severity score was significantly higher among controls asymptomatic for diarrhoeal disease compared to cases with rotavirus diarrhoea (p = 0.02).

CONCLUSION

The morphological changes associated with EED may confer protection against rotavirus infection and subsequent diarrhoeal disease among children. Further research is critically needed to better understand the complex mechanisms by which nutritional status and EED may impact susceptibility to rotavirus in early life.

Sero-prevalence of arthropod-borne viral infections among Lukanga swamp residents in Zambia

INTRODUCTION

The re-emergence of vector borne diseases affecting millions of people in recent years has drawn attention to arboviruses globally. Here, we report on the sero-prevalence of chikungunya virus (CHIKV), dengue virus (DENV), mayaro virus (MAYV) and zika virus (ZIKV) in a swamp community in Zambia.

METHODS

We collected blood and saliva samples from residents of Lukanga swamps in 2016 during a mass-cholera vaccination campaign. Over 10,000 residents were vaccinated with two doses of Shanchol™ during this period. The biological samples were collected prior to vaccination (baseline) and at specified time points after vaccination. We tested a total of 214 baseline stored serum samples for IgG antibodies against NS1 of DENV and ZIKV and E2 of CHIKV and MAYV on ELISA. We defined sero-prevalence as the proportion of participants with optical density (OD) values above a defined cut-off value, determined using a finite mixture model.

RESULTS

Of the 214 participants, 79 (36.9%; 95% CI 30.5-43.8) were sero-positive for Chikungunya; 23 (10.8%; 95% CI 6.9-15.7) for Zika, 36 (16.8%; 95% CI 12.1-22.5) for Dengue and 42 (19.6%; 95% CI 14.5-25.6) for Mayaro. Older participants were more likely to have Zika virus whilst those involved with fishing activities were at greater risk of contracting Chikungunya virus. Among all the antigens tested, we also found that Chikungunya saliva antibody titres correlated with baseline serum titres (Spearman's correlation coefficient = 0.222; p = 0.03).

CONCLUSION

Arbovirus transmission is occurring in Zambia. This requires proper screening tools as well as surveillance data to accurately report on disease burden in Zambia.

Trends in CD4 and viral load testing 2005 to 2018: multi-cohort study of people living with HIV in Southern Africa

INTRODUCTION

The World Health Organization (WHO) recommends a CD4 cell count before starting antiretroviral therapy (ART) to detect advanced HIV disease, and routine viral load (VL) testing following ART initiation to detect treatment failure. Donor support for CD4 testing has declined to prioritize access to VL monitoring. We examined trends in CD4 and VL testing among adults (≥15 years of age) starting ART in Southern Africa.

METHODS

We analysed data from 14 HIV treatment programmes in Lesotho, Malawi, Mozambique, South Africa, Zambia and Zimbabwe in 2005 to 2018. We examined the frequency of CD4 and VL testing, the percentage of adults with CD4 or VL tests, and among those having a test, the percentage starting ART with advanced HIV disease (CD4 count <200 cells/mm3 ) or failing to suppress viral replication (>1000 HIV-RNA copies/mL) after ART initiation. We used mixed effect logistic regression to assess time trends adjusted for age and sex.

RESULTS

Among 502,456 adults, the percentage with CD4 testing at ART initiation decreased from a high of 78.1% in 2008 to a low of 38.0% in 2017; the probability declined by 14% each year (odds ratio (OR) 0.86; 95% CI 0.86 to 0.86). Frequency of CD4 testing also declined. The percentage starting ART with advanced HIV disease declined from 83.3% in 2005 to 23.5% in 2018; each year the probability declined by 20% (OR 0.80; 95% CI 0.80 to 0.81). VL testing after starting ART varied; 61.0% of adults in South Africa and 10.7% in Malawi were tested, but fewer than 2% were tested in the other four countries. The probability of VL testing after ART start increased only modestly each year (OR 1.06; 95% CI 1.05 to 1.06). The percentage with unsuppressed VL was 8.6%. There was no evidence of a decrease in unsuppressed VL over time (OR 1.00; 95% CI 0.99 to 1.01).

CONCLUSIONS

CD4 cell counting declined over time, including testing at the start of ART, despite the fact that many patients still initiated ART with advanced HIV disease. Without CD4 testing and expanded VL testing many patients with advanced HIV disease and treatment failure may go undetected, threatening the effectiveness of ART in sub-Saharan Africa.

Impact evaluation of the free maternal healthcare policy on the risk of neonatal and infant deaths in four sub-Saharan African countries: a quasi-experimental design with propensity score Kernel matching and difference in differences analysis

OBJECTIVE

Despite the huge financial investment in the free maternal healthcare policy (FMHCP) by the Governments of Ghana and Burkina Faso, no study has quantified the impact of FMHCP on the relative reduction in neonatal and infant mortality rates using a more rigorous matching procedure with the difference in differences (DID) analysis. This study used several rounds of publicly available population-based complex survey data to determine the impact of FMHCP on neonatal and infant mortality rates in these two countries.

DESIGN

A quasi-experimental study to evaluate the FMHCP implemented in Burkina Faso and Ghana between 2007 and 2014.

SETTING

Demographic and health surveys and maternal health surveys conducted between 2000 and 2014 in Ghana, Burkina Faso, Nigeria and Zambia.

PARTICIPANTS

Children born 5 years preceding the survey in Ghana, Burkina Faso, Nigeria and Zambia.

PRIMARY OUTCOME MEASURES

Neonatal and infant mortality rates.

RESULTS

The Propensity Score Kernel Matching coupled with DID analysis with modified Poisson showed that the FMHCP was associated with a 45% reduction in the risk of neonatal mortality rate in Ghana and Burkina Faso compared with Nigeria and Zambia (adjusted relative risk (aRR)=0.55, 95% CI: 0.40 to 0.76, p<0.001). In addition, infant mortality rate has reduced significantly in both Ghana and Burkina Faso by approximately 54% after full implementation of FMHCP compared with Nigeria and Zambia (aRR=0.46, 95% CI: 0.36 to 0.59, p<0.001).

CONCLUSION

The FMHCP had a significant impact and still remains relevant in achieving Sustainable Development Goal 3 and could provide lessons for other sub-Saharan countries in the design and implementation of a similar policy.

Marketing of breast-milk substitutes in Zambia: evaluation of compliance to the international regulatory code

Background

We sought to assess the level of non-compliance with the International Code of Marketing breast-milk substitutes (BMS) and/or Statutory Instrument (SI) Number 48 of 2006 of the Laws of Zambia in two suburbs, Kalingalinga and Chelstone, in Zambia.

Methods

This was a cross sectional survey. Shop owners (80), health workers (8) and mothers (214) were interviewed. BMS labels and advertisements (62) were observed. The primary outcome was mean non-compliance defined as the number of article violations divided by the total 'obtainable' violations. The score ranges from 0 to 1 with 0 representing no violations in all the articles and one representing violations in all the articles.

Results

A total of 62 BMS were assessed. The mean non-compliance score by manufacturers in terms of violations in labelling of BMS was 0.33 (SD = 0.28; 95% CI: 0.26, 0.40). These violations were mainly due to labels containing pictures or graphics representing an infant. 80 shops were also assessed with mean non-compliance score in respect of violations in tie-in-sales, special display, and contact with mothers at the shop estimated as 0.14 (SD = 0.14; 95% CI: 0.11, 0.18).

Conclusions

Non-compliance with the Code and/or the local SI is high after 10 years of domesticating the Code.

Effect of a behaviour change intervention on the quality of peri-urban sanitation in Lusaka, Zambia: a randomised controlled trial

BACKGROUND

Poor sanitation in peri-urban areas is a growing public health problem. We tested a scalable, demand-side behaviour change intervention to motivate landlords to improve the quality of shared toilets within their plots.

METHODS

We did a residential plot-randomised controlled trial in a peri-urban community in Lusaka, Zambia. We enrolled adult resident landlords on plots where at least one tenant lived. We allocated landlords 1:1 to intervention and control arms on the basis of a random number sequence. The intervention was developed using the Behaviour Centred Design approach and consisted of a series of group meetings designed to motivate sanitation quality improvement as a way to build wealth and reduce on-plot conflict; no subsidies or materials were provided. The control group received no intervention. The four primary outcomes were having a rotational cleaning system in place (to improve hygiene); having a solid door on the toilet used by tenants with an inside lock (for privacy); having an outside lock (for security); and having a sealed toilet (to reduce smell and contamination). We measured outcomes 1 month before the start of the intervention and 4 months after the end of the intervention. Data collectors measuring outcomes were blinded to group assignment. We analysed outcomes by intention to treat, including all landlords with study-end results. Because the outcomes were assumed to not be independent, we used a family-wise error rate of 0·05 to calculate an adjusted significance level of 0·0253. This study was registered with ClinicalTrials.gov, number NCT03174015.

FINDINGS

Between June 9 and July 6, 2017, 1085 landlords were enrolled and randomly assigned to the intervention (n=543) or the control group (n=542). The intervention was delivered from Aug 1, 2017, and evaluated from Feb 15 to March 5, 2018. Analysis was based on the 474 intervention and 454 control landlords surveyed at study end. The intervention was associated with improvements in the prevalence of cleaning rotas (relative risk 1·16, 95% CI 1·05-1·30; p=0·0011), inside locks (1·34, 1·10-1·64; p=0·00081), outside locks (1·27, 1·06-1·52; p=0·0028), and toilets with simple covers or water seals (1·25, 1·04-1·50; p=0·0063).

INTERPRETATION

It is possible to improve the structural quality and cleanliness of shared sanitation by targeting landlords with a scalable, theory-driven behaviour change intervention without subsidy or provision of the relevant infrastructure.

FUNDING

Sanitation and Hygiene Applied Research for Equity.

Prescribing patterns and compliance with World Health Organization recommendations for the management of severe malaria: a modified cohort event monitoring study in public health facilities in Ghana and Uganda

BACKGROUND

Injectable artesunate (AS) is the World Health Organization (WHO) recommended medication for the treatment of severe malaria followed with an oral artemisinin-based combination therapy (ACT). There are few studies indicating how physicians prescribe injectable AS, injectable quinine (Q) or injectable artemether (AR) and ACT for severe malaria. This study was undertaken to evaluate prescription compliance to the WHO recommendation in 8 public health facilities in Ghana and Uganda. This was a modified cohort event monitoring study involving patients who were administered with injectable anti-malarial for treatment of presumed or confirmed severe malaria. Patients prescribed at least one dose of injectable artesunate, artemether or quinine qualified to enrol in the study. Patients were recruited at inpatient facilities and followed up in the hospital, by phone or at home. Following WHO recommendations, patients are to be prescribed 3 doses of injectable AS, Q or AR for at least 24 h followed with oral ACT. Compliance rate was estimated as the number of patient prescriptions that met the WHO recommendation for treatment of severe malaria divided by the total number of patients who completed the study by end of follow up. Log-binomial regression model was used to identify predictors for compliance. Based on the literature and limitations of available data from the patients' record, the diagnosis results, age, gender, weight, and country were considered as potential predictors of prescriber adherence to the WHO recommendations.

RESULTS

A total of 1191 patients completed the study, of which 93% were prescribed injectable AS, 3.1% (injectable AR or Q) with 32.5% prescribed follow-on oral ACT and 26% on concomitant antibiotics. 391 (32.8%) were in Ghana and 800 (67.2%) in Uganda. There were 582 (48.9%) women. The median age was 3.9 years (IQR = 2, 9) and median weight was 13 kg (IQR = 10, 20). Of the 1191 patients, 329 of the prescriptions complied with the WHO recommendation (compliance rate = 27.6%; 95% CI = [25.2, 30.2]). Diagnostic results (Adjusted prevalence ratio (aPR) = 4.56; 95% = [3.42, 6.08]; p < 0.0001) and weight (20 + kg vs < 10 kg: aPR = 0.65; 95% = [0.44, 0.96]; p = 0.015) were identified as factors independently associated with compliance.

CONCLUSION

Injectable AS is the most commonly prescribed medicine in the management of severe malaria in Ghana and Uganda. However, adherence to the WHO recommendation of at least 3 doses of injectable anti-malarial in 24 h followed by a full course of ACT is low, at less than 30%.

Early linear growth retardation: results of a prospective study of Zambian infants

BACKGROUND

Linear growth retardation is the most dominant nutritional problem globally. We aimed to describe linear growth trajectory among infants under 2 years of age using the WHO growth velocity standards.

METHOD

This was a prospective cohort study of infants enrolled at 6 weeks of age and followed up for up to 24 months in Kamwala Urban Health Centre, Lusaka, Zambia. The study was conducted between April 2013 and March 2015. Infants were enrolled if they were 6-12 weeks of age and the mother was willing to participate voluntarily and provided informed consent. Anthropometric data were collected at scheduled clinic visits at 1 month, 2 months, 3 months, then quarterly until the infant was 24 months old. We defined linear growth velocity as the rate of change in height. We estimated linear growth velocity as the first derivative of the penalized cubic spline mixed effects model.

RESULTS

A total of 338 children were included in the analysis. Of these, 185 (54.7%) were female, 115 (34.1%) were born to HIV positive mothers and thus classified as HIV Exposed (HE). The mean age of children at enrollment was 1.6 months (SD = 0.15). On average, the growth velocity for 3-month length increments conditional on age were 0-3 months = 2.97 cm/3mo (95%CI = 2.69, 3.25); 3-6 months = 2.62 cm/3mo (95%CI = 2.38, 2.87); 6-9 months = 1.57 cm/3mo (95%CI = 1.43, 1.71); 9-12 months = 1.18 cm/3mo (95%CI = 1.08, 1.28); 12-15 month = 1.14 cm/3mo (95%CI = 1.02, 1.27); 15-18 months = 0.87 cm/3mo (95%CI = 0.79, 0.96); 18-21 months = 0.80 cm/3mo (95%CI = 0.72, 0.89); and 21-24 months = 0.86 cm/3mo (95%CI = 0.77, 0.96). For both boys and girls, the growth velocity in our cohort were consistently below the 3rd percentile of the WHO linear growth velocity standard. The estimated mean height and the age at which growth begins to falter were 68.6 cm (95%CI = 68.0, 69.2) and 13.6 months (95%CI = 13.2, 14.1) respectively.

CONCLUSION

We found slower rate of growth among otherwise healthy Zambian infants. The data suggests that growth retardation is universal and profound in this cohort and may have already been occurring in utero.

Field performance evaluation of dual rapid HIV and syphilis tests in three antenatal care clinics in Zambia

This cross-sectional study of 3212 pregnant women assessed the field performance, acceptability, and feasibility of two dual HIV/syphilis rapid diagnostic tests, the Chembio DPP HIV-syphilis Assay and the SD Bioline HIV/syphilis Duo in antenatal clinics. Sensitivity and specificity for HIV and syphilis were calculated compared to the rapid Determine HIV-1/2 with Uni-Gold to confirm positive results for HIV and the Treponema pallidum particle agglutination assay for syphilis. RPR titers ≥1:4 were used to define active syphilis detection. Acceptability and feasibility were assessed using self-reported questionnaires. For Chembio, the HIV sensitivity was 90.6% (95%CI = 87.4, 93.0) and specificity was 97.2% (95%CI = 96.2, 97.8); syphilis sensitivity was 68.6% (95%CI = 61.9, 74.6) and specificity was 98.5% (95%CI = 97.8, 98.9). For SD Bioline, HIV sensitivity was 89.4% (95%CI = 86.1, 92.0) and specificity was 96.3% (95%CI = 95.3, 97.1); syphilis sensitivity was 66.2% (95%CI = 59.4, 72.4) and specificity was 97.2% (95%CI = 96.4, 97.9). Using the reference for active syphilis, syphilis sensitivity was 84.7% (95%CI = 76.1, 90.6) for Chembio and 81.6% (95%CI = 72.7, 88.1) for SD Bioline. Both rapid diagnostic tests were assessed as highly acceptable and feasible. In a field setting, the performance of both rapid diagnostic tests was comparable to other published field evaluations and each was rated highly acceptable and feasible. These findings can be used to guide further research and proposed scale up in antenatal clinic settings.

The prevalence of submicroscopic Plasmodium falciparum gametocyte carriage and multiplicity of infection in children, pregnant women and adults in a low malaria transmission area in Southern Ghana

BACKGROUND

The gametocyte stage of Plasmodium falciparum is considered an important target for disrupting malaria transmission. Indications are that various demographic groups, such as children and pregnant women may differ in risk of harbouring gametocytes, which may be crucial for targeted control. In this study, the relationship between the prevalence and multiplicity of P. falciparum, asexual parasite infections and gametocytaemia was assessed in three different demographic groups in an area of southern Ghana with low malaria endemicity. Levels of antibody responses to Pfs230 were also assessed as a proxy for the presence of gametocytes.

METHODS

The study involved multiple cross-sectional sampling of children (N = 184, aged 2-15 years), male and non-pregnant female adults (N = 154, aged 16-65 years) and pregnant women (N = 125, aged 18-45 years) from Asutsuare in the Shai Osudoku District of Greater Accra Region in Ghana. Asexual parasitaemia was detected by microscopy and PCR, and gametocytaemia was assessed by Pfs25-real time PCR. Multiclonal P. falciparum infections were estimated by msp2 genotyping and an indirect ELISA was used to measure plasma IgG antibodies to Pfs230 antigen.

RESULTS

Overall, children and pregnant women had higher prevalence of submicroscopic gametocytes (39.5% and 29.7%, respectively) compared to adults (17.4%). Multiplicity of infection observed amongst children (3.1) and pregnant women (3.9) were found to be significantly higher (P = 0.006) compared with adults (2.7). Risk of gametocyte carriage was higher in individuals infected with P. falciparum having both Pfmsp2 3D7 and FC27 parasite types (OR = 5.92, 95% CI 1.56-22.54, P = 0.009) compared with those infected with only 3D7 or FC27 parasite types. In agreement with the parasite prevalence data, anti-Pfs230 antibody levels were lower in gametocyte positive adults (β = - 0.57, 95% CI - 0.81, - 0.34, P < 0.001) compared to children.

CONCLUSIONS

These findings suggest that children and pregnant women are particularly important as P. falciparum submicroscopic gametocyte reservoirs and represent important focus groups for control interventions. The number of clones increased in individuals carrying gametocytes compared to those who did not carry gametocytes. The higher anti-gametocyte antibody levels in children suggests recent exposure and may be a marker of gametocyte carriage.