Trends in SARS-CoV-2 seroprevalence among pregnant women attending first antenatal care visits in Zambia: A repeated cross-sectional survey, 2021-2022.

SARS-CoV-2 serosurveys help estimate the extent of transmission and guide the allocation of COVID-19 vaccines. We measured SARS-CoV-2 seroprevalence among women attending ANC clinics to assess exposure trends over time in Zambia. We conducted repeated cross-sectional SARS-CoV-2 seroprevalence surveys among pregnant women aged 15-49 years attending their first ANC visits in four districts of Zambia (two urban and two rural) during September 2021-September 2022. Serologic testing was done using a multiplex bead assay which detects IgG antibodies to the nucleocapsid protein and the spike protein receptor-binding domain (RBD). We calculated monthly SARS-CoV-2 seroprevalence by district. We also categorized seropositive results as infection alone, infection and vaccination, or vaccination alone based on anti-RBD and anti-nucleocapsid test results and self-reported COVID-19 vaccination status (vaccinated was having received ≥1 dose). Among 8,304 participants, 5,296 (63.8%) were cumulatively seropositive for SARS-CoV-2 antibodies from September 2021 through September 2022. SARS-CoV-2 seroprevalence primarily increased from September 2021 to September 2022 in three districts (Lusaka: 61.8-100.0%, Chongwe: 39.6-94.7%, Chipata: 56.5-95.0%), but in Chadiza, seroprevalence increased from 27.8% in September 2021 to 77.2% in April 2022 before gradually dropping to 56.6% in July 2022. Among 5,906 participants with a valid COVID-19 vaccination status, infection alone accounted for antibody responses in 77.7% (4,590) of participants. Most women attending ANC had evidence of prior SARS-CoV-2 infection and most SARS-CoV-2 seropositivity was infection-induced. Capturing COVID-19 vaccination status and using a multiplex bead assay with anti-nucleocapsid and anti-RBD targets facilitated distinguishing infection-induced versus vaccine-induced antibody responses during a period of increasing COVID-19 vaccine coverage in Zambia. Declining seroprevalence in Chadiza may indicate waning antibodies and a need for booster vaccines. ANC clinics have a potential role in ongoing SARS-CoV-2 serosurveillance and can continue to provide insights into SARS-CoV-2 antibody dynamics to inform near real-time public health responses.

COVID-19 mortality sentinel surveillance at a tertiary referral hospital in Lusaka, Zambia, 2020-2021.

Deaths from COVID-19 likely exceeded official statistics in Zambia because of limited testing and incomplete death registration. We describe a sentinel COVID-19 mortality surveillance system in Lusaka, Zambia. We analyzed surveillance data on deceased persons of all ages undergoing verbal autopsy (VA) and COVID-19 testing at the University Teaching Hospital (UTH) mortuary in Lusaka, Zambia, from April 2020 through August 2021. VA was done by surveillance officers for community deaths and in-patient deaths that occurred <48 hours after admission. A standardized questionnaire about the circumstances proximal to death was used, with a probable cause of death assigned by a validated computer algorithm. Nasopharyngeal specimens from deceased persons were tested for COVID-19 using polymerase chain reaction and rapid diagnostic tests. We analyzed the cause of death by COVID-19 test results. Of 12,919 deceased persons at UTH mortuary during the study period, 5,555 (43.0%) had a VA and COVID-19 test postmortem, of which 79.7% were community deaths. Overall, 278 (5.0%) deceased persons tested COVID-19 positive; 7.1% during waves versus 1.4% during nonwave periods. Most (72.3%) deceased persons testing COVID-19 positive reportedly had fever, cough, and/or dyspnea and most (73.5%) reportedly had an antemortem COVID-19 test. Common causes of death for those testing COVID-19 positive included acute cardiac disease (18.3%), respiratory tract infections (16.5%), other types of cardiac diseases (12.9%), and stroke (7.2%). A notable portion of deceased persons at a sentinel site in Lusaka tested COVID-19 positive during waves, supporting the notion that deaths from COVID-19 might have been undercounted in Zambia. Many had displayed classic COVID-19 symptoms and been tested before death yet nevertheless died in the community, potentially indicating strained medical services during waves. The high proportion of cardiovascular diseases deaths might reflect the hypercoagulable state during severe COVID-19. Early supportive treatment and availability of antivirals might lessen future mortality.

Test negative case-control study of COVID-19 vaccine effectiveness for symptomatic SARS-CoV-2 infection among healthcare workers: Zambia, 2021-2022.

OBJECTIVES: The study aim was to evaluate vaccine effectiveness (VE) of COVID-19 vaccines in preventing symptomatic COVID-19 among healthcare workers (HCWs) in Zambia. We sought to answer the question, 'What is the vaccine effectiveness of a complete schedule of the SARS-CoV-2 vaccine in preventing symptomatic COVID-19 among HCWs in Zambia?' DESIGN/SETTING: We conducted a test-negative case-control study among HCWs across different levels of health facilities in Zambia offering point of care testing for COVID-19 from May 2021 to March 2022. PARTICIPANTS: 1767 participants entered the study and completed it. Cases were HCWs with laboratory-confirmed SARS-CoV-2 and controls were HCWs who tested SARS-CoV-2 negative. Consented HCWs with documented history of vaccination for COVID-19 (vaccinated HCWs only) were included in the study. HCWs with unknown test results and unknown vaccination status, were excluded. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was VE among symptomatic HCWs. Secondary outcomes were VE by: SARS-CoV-2 variant strains based on the predominant variant circulating in Zambia (Delta during May 2021 to November 2021 and Omicron during December 2021 to March 2022), duration since vaccination and vaccine product. RESULTS: We recruited 1145 symptomatic HCWs. The median age was 30 years (IQR: 26-38) and 789 (68.9%) were women. Two hundred and eighty-two (24.6%) were fully vaccinated. The median time to full vaccination was 102 days (IQR: 56-144). VE against symptomatic SARS-CoV-2 infection was 72.7% (95% CI: 61.9% to 80.7%) for fully vaccinated participants. VE was 79.4% (95% CI: 58.2% to 90.7%) during the Delta period and 37.5% (95% CI: -7.0% to 63.3%) during the Omicron period. CONCLUSIONS: COVID-19 vaccines were effective in reducing symptomatic SARS-CoV-2 among Zambian HCWs when the Delta variant was circulating but not when Omicron was circulating. This could be related to immune evasive characteristics and/or waning immunity. These findings support accelerating COVID-19 booster dosing with bivalent vaccines as part of the vaccination programme to reduce COVID-19 in Zambia.

Characteristics of cases and deaths arising from SARS-CoV-2 infection in Zambia: March 2020 to April 2021.

Introduction: since March 2020, Zambia has been experiencing a SARS-CoV-2 epidemic. Little data has been reported on cases and deaths arising from COVID-19 in Africa. We described the demographic characteristics of these cases and deaths in Zambia. Methods: we analyzed data on all persons testing positive for SARS-CoV-2 from 18th March 2020 to 25th April 2021 in Zambia. COVID-19 cases were identified through port-of-entry surveillance, contact-tracing, health-care-worker testing, health-facility-based and community-based screening and community-death screening. All diagnoses were confirmed using real-time-polymerase-chain-reaction and rapid-antigen-test-kits of nasopharyngeal specimens. We analyzed age, sex, and date-of-reporting according to whether the cases or deaths occurred during the first wave (1st July to 15th September 2020) or the second wave (15th December 2020 to 10th April 2021). We computed Mann-Whitney-U-test to compare medians of continuous variables and chi-square tests to compare differences between proportions using R. Results: a total 1,246 (1.36%) deaths were recorded among 91,378 confirmed cases during March 2020-April 2021 in Zambia. Persons who died were older than those who did not (median age 50 years versus 32.0 years, p< 0.001). Although only 4.7% of cases were among persons aged >60 years, most deaths (31.6%) occurred in this age group (p<0.001). More deaths (83.5%) occurred in the community than in health facilities (p<0.001). Conclusion: during the SARS-CoV-2 epidemic in Zambia, most deaths occurred in the community, indicating potential gaps in public health messaging about COVID-19. Improving health-seeking behaviors for COVID-19 through public messaging campaigns and engaging key community stakeholders in Zambia might reduce avoidable mortality. As the group most impacted by COVID-19 mortality, older persons might need enhanced outreach and linkage to care.

Spatial factors for COVID-19 associated community deaths in an urban area of Lusaka, Zambia: an observational study.

We retrospectively analyzed spatial factors for coronavirus disease 2019 (COVID-19)-associated community deaths i.e., brought-in-dead (BID) in Lusaka, Zambia, between March and July 2020. A total of 127 cases of BID with geocoordinate data of their houses were identified during the study period. Median interquartile range (IQR) of the age of these cases was 49 (34-70) years old, and 47 cases (37.0%) were elderly individuals over 60 years old. Seventy-five cases (75%) of BID were identified in July 2020, when the total number of cases and deaths was largest in Zambia. Among those whose information regarding their underlying medical condition was available, hypertension was most common (22.9%, 8/35). Among Lusaka's 94 townships, the numbers (median, IQR) of cases were significantly larger in those characterized as unplanned residential areas compared to planned areas (1.0, 0.0-4.0 vs 0.0, 0.0-1.0; p=0.030). The proportion of individuals who require more than 30 minutes to obtain water was correlated with a larger number of BID cases per 105 population in each township (rho=0.28, p=0.006). The number of BID cases was larger in unplanned residential areas, which highlighted the importance of targeted public health interventions specifically to those areas to reduce the total number of COVID-19 associated community deaths in Lusaka. Brought-in-dead surveillance might be beneficial in monitoring epidemic conditions of COVID-19 in such high-risk areas. Furthermore, inadequate access to water, sanitation, and hygiene (WASH) might be associated with such distinct geographical distributions of COVID-19 associated community deaths in Lusaka, Zambia.

Spatial factors for COVID-19 associated community deaths in an urban area of Lusaka, Zambia: an observational study

We retrospectively analyzed spatial factors for coronavirus disease 2019 (COVID-19)-associated community deaths i.e., brought-in-dead (BID) in Lusaka, Zambia, between March and July 2020. A total of 127 cases of BID with geocoordinate data of their houses were identified during the study period. Median interquartile range (IQR) of the age of these cases was 49 (34-70) years old, and 47 cases (37.0%) were elderly individuals over 60 years old. Seventy-five cases (75%) of BID were identified in July 2020, when the total number of cases and deaths was largest in Zambia. Among those whose information regarding their underlying medical condition was available, hypertension was most common (22.9%, 8/35). Among Lusaka's 94 townships, the numbers (median, IQR) of cases were significantly larger in those characterized as unplanned residential areas compared to planned areas (1.0, 0.0-4.0 vs 0.0, 0.0-1.0; p=0.030). The proportion of individuals who require more than 30 minutes to obtain water was correlated with a larger number of BID cases per 105 population in each township (rho=0.28, p=0.006). The number of BID cases was larger in unplanned residential areas, which highlighted the importance of targeted public health interventions specifically to those areas to reduce the total number of COVID-19 associated community deaths in Lusaka. Brought-in-dead surveillance might be beneficial in monitoring epidemic conditions of COVID-19 in such high-risk areas. Furthermore, inadequate access to water, sanitation, and hygiene (WASH) might be associated with such distinct geographical distributions of COVID-19 associated community deaths in Lusaka, Zambia.

Comparison of COVID-19 Pandemic Waves in 10 Countries in Southern Africa, 2020-2021.

We used publicly available data to describe epidemiology, genomic surveillance, and public health and social measures from the first 3 COVID-19 pandemic waves in southern Africa during April 6, 2020-September 19, 2021. South Africa detected regional waves on average 7.2 weeks before other countries. Average testing volume 244 tests/million/day) increased across waves and was highest in upper-middle-income countries. Across the 3 waves, average reported regional incidence increased (17.4, 51.9, 123.3 cases/1 million population/day), as did positivity of diagnostic tests (8.8%, 12.2%, 14.5%); mortality (0.3, 1.5, 2.7 deaths/1 million populaiton/day); and case-fatality ratios (1.9%, 2.1%, 2.5%). Beta variant (B.1.351) drove the second wave and Delta (B.1.617.2) the third. Stringent implementation of safety measures declined across waves. As of September 19, 2021, completed vaccination coverage remained low (8.1% of total population). Our findings highlight opportunities for strengthening surveillance, health systems, and access to realistically available therapeutics, and scaling up risk-based vaccination.

Effectiveness of two doses of Euvichol-plus oral cholera vaccine in response to the 2017/2018 outbreak: a matched case-control study in Lusaka, Zambia.

INTRODUCTION: Zambia experienced a major cholera outbreak in 2017-2018, with more than 5905 cases reported countrywide, predominantly from the peri-urban slums of Lusaka city. The WHO recommends the use of oral cholera vaccines (OCVs) together with traditional control measures, including health promotion, provision of safe water and improving sanitation, in cholera endemic areas and during cholera outbreaks. In response to this outbreak, the Zambian government implemented the OVC campaign and administered the Euvichol-plus vaccine in the high-risk subdistricts of Lusaka. Although OCVs have been shown to be effective in preventing cholera infection in cholera endemic and outbreak settings, the effectiveness of the Euvichol-plus vaccine has not yet been evaluated in Zambia. This study aimed to determine the effectiveness of two doses of OCV administered during the 2017/2018 vaccination campaign. METHODS: We conducted a matched case-control study involving 79 cases and 316 controls following the mass vaccination campaign in the four subdistricts of Lusaka (Chawama, Chipata, Kanyama and Matero). Matching of controls was based on the place of residence, age and sex. Conditional logistic regression was used for analysis. Adjusted OR (AOR), 95% CI and vaccine effectiveness (1-AOR) for two doses of Euvichol-plus vaccine and any dose were estimated (p<0.05). RESULTS: The AOR vaccine effectiveness for two doses of Euvichol-plus OCV was 81.0% (95% CI 66.0% to 78.0%; p<0.01). Secondary analysis showed that vaccine effectiveness for any dose was 74.0% (95% CI 50.0% to 86.0%; p<0.01). CONCLUSION: These findings show that two doses of Euvichol-plus OCV are effective in a cholera outbreak setting in Lusaka, Zambia. The findings also indicate that two doses are more effective than a single dose and thus support the use of two doses of the vaccine as part of an integrated intervention to cholera control during outbreaks.

COVID-19 Vaccine Effectiveness during a Prison Outbreak when Omicron was the Dominant Circulating Variant-Zambia, December 2021.

During a COVID-19 outbreak in a prison in Zambia from December 14 to 19, 2021, a case-control study was done to measure vaccine effectiveness (VE) against infection and symptomatic infection, when the Omicron variant was the dominant circulating variant. Among 382 participants, 74.1% were fully vaccinated, and the median time since full vaccination was 54 days. There were no hospitalizations or deaths. COVID-19 VE against any SARS-CoV-2 infection was 64.8%, and VE against symptomatic SARS-CoV-2 infection was 72.9%. COVID-19 vaccination helped protect incarcerated persons against SARS-CoV-2 infection during an outbreak while Omicron was the dominant variant in Zambia. These findings provide important local evidence that might be used to increase COVID-19 vaccination in Zambia and other countries in Africa.

SARS-CoV-2 Prevalence among Outpatients during Community Transmission, Zambia, July 2020.

During the July 2020 first wave of severe acute respiratory syndrome coronavirus 2 in Zambia, PCR-measured prevalence was 13.4% among outpatients at health facilities, an absolute difference of 5.7% compared with prevalence among community members. This finding suggests that facility testing might be an effective strategy during high community transmission.

Prevalence of Severe Acute Respiratory Syndrome Coronavirus 2 Among Healthcare Workers-Zambia, July 2020.

BACKGROUND: Healthcare workers (HCWs) in Zambia have become infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19). However, SARS-CoV-2 prevalence among HCWs is not known in Zambia. METHODS: We conducted a cross-sectional SARS-CoV-2 prevalence survey among Zambian HCWs in 20 health facilities in 6 districts in July 2020. Participants were tested for SARS-CoV-2 infection using polymerase chain reaction (PCR) and for SARS-CoV-2 antibodies using enzyme-linked immunosorbent assay (ELISA). Prevalence estimates and 95% confidence intervals (CIs), adjusted for health facility clustering, were calculated for each test separately, and a combined measure for those who had PCR and ELISA was performed. RESULTS: In total, 660 HCWs participated in the study, with 450 (68.2%) providing a nasopharyngeal swab for PCR and 575 (87.1%) providing a blood specimen for ELISA. Sixty-six percent of participants were females, and median age was 31.5 years (interquartile range, 26.2-39.8). The overall prevalence of the combined measure was 9.3% (95% CI, 3.8%-14.7%). PCR-positive prevalence of SARS-CoV-2 was 6.6% (95% CI, 2.0%-11.1%), and ELISA-positive prevalence was 2.2% (95% CI, .5%-3.9%). CONCLUSIONS: SARS-CoV-2 prevalence among HCWs was similar to a population-based estimate (10.6%) during a period of community transmission in Zambia. Public health measures such as establishing COVID-19 treatment centers before the first cases, screening for COVID-19 symptoms among patients who access health facilities, infection prevention and control trainings, and targeted distribution of personal protective equipment based on exposure risk might have prevented increased SARS-CoV-2 transmission among Zambian HCWs.

Prevalence of SARS-CoV-2 in six districts in Zambia in July, 2020: a cross-sectional cluster sample survey.

BACKGROUND: Between March and December, 2020, more than 20 000 laboratory-confirmed cases of SARS-CoV-2 infection were reported in Zambia. However, the number of SARS-CoV-2 infections is likely to be higher than the confirmed case counts because many infected people have mild or no symptoms, and limitations exist with regard to testing capacity and surveillance systems in Zambia. We aimed to estimate SARS-CoV-2 prevalence in six districts of Zambia in July, 2020, using a population-based household survey. METHODS: Between July 4 and July 27, 2020, we did a cross-sectional cluster-sample survey of households in six districts of Zambia. Within each district, 16 standardised enumeration areas were randomly selected as primary sampling units using probability proportional to size. 20 households from each standardised enumeration area were selected using simple random sampling. All members of selected households were eligible to participate. Consenting participants completed a questionnaire and were tested for SARS-CoV-2 infection using real-time PCR (rtPCR) and anti-SARS-CoV-2 antibodies using ELISA. Prevalence estimates, adjusted for the survey design, were calculated for each diagnostic test separately, and combined. We applied the prevalence estimates to census population projections for each district to derive the estimated number of SARS-CoV-2 infections. FINDINGS: Overall, 4258 people from 1866 households participated in the study. The median age of participants was 18·2 years (IQR 7·7-31·4) and 50·6% of participants were female. SARS-CoV-2 prevalence for the combined measure was 10·6% (95% CI 7·3-13·9). The rtPCR-positive prevalence was 7·6% (4·7-10·6) and ELISA-positive prevalence was 2·1% (1·1-3·1). An estimated 454 708 SARS-CoV-2 infections (95% CI 312 705-596 713) occurred in the six districts between March and July, 2020, compared with 4917 laboratory-confirmed cases reported in official statistics from the Zambia National Public Health Institute. INTERPRETATION: The estimated number of SARS-CoV-2 infections was much higher than the number of reported cases in six districts in Zambia. The high rtPCR-positive SARS-CoV-2 prevalence was consistent with observed community transmission during the study period. The low ELISA-positive SARS-CoV-2 prevalence might be associated with mitigation measures instituted after initial cases were reported in March, 2020. Zambia should monitor patterns of SARS-CoV-2 prevalence and promote measures that can reduce transmission. FUNDING: US Centers for Disease Control and Prevention.

Zambia field epidemiology training program: strengthening health security through workforce development.

The Zambia Field Epidemiology Training Program (ZFETP) was established by the Ministry of Health (MoH) during 2014, in order to increase the number of trained field epidemiologists who can investigate outbreaks, strengthen disease surveillance, and support data-driven decision making. We describe the ZFETP´s approach to public health workforce development and health security strengthening, key milestones five years after program launch, and recommendations to ensure program sustainability. Program description: ZFETP was established as a tripartite arrangement between the Zambia MoH, the University of Zambia School of Public Health, and the U.S. Centers for Disease Control and Prevention. The program runs two tiers: Advanced and Frontline. To date, ZFETP has enrolled three FETP-Advanced cohorts (training 24 residents) and four Frontline cohorts (training 71 trainees). In 2016, ZFETP moved organizationally to the newly established Zambia National Public Health Institute (ZNPHI). This re-positioning raised the program´s profile by providing residents with increased opportunities to lead high-profile outbreak investigations and analyze national surveillance data-achievements that were recognized on a national stage. These successes attracted investment from the Government of Republic of Zambia (GRZ) and donors, thus accelerating field epidemiology workforce capacity development in Zambia. In its first five years, ZFETP achieved early success due in part to commitment from GRZ, and organizational positioning within the newly formed ZNPHI, which have catalyzed ZFETP´s institutionalization. During the next five years, ZFETP seeks to sustain this momentum by expanding training of both tiers, in order to accelerate the professional development of field epidemiologists at all levels of the public health system.

Konzo outbreak in the Western Province of Zambia.

OBJECTIVE: To identify the etiology of an outbreak of spastic paraparesis among women and children in the Western Province of Zambia suspected to be konzo. METHODS: We conducted an outbreak investigation of individuals from Mongu District, Western Province, Zambia, who previously developed lower extremity weakness. Cases were classified with the World Health Organization definition of konzo. Active case finding was conducted through door-to-door evaluation in affected villages and sensitization at local health clinics. Demographic, medical, and dietary history was used to identify common exposures in all cases. Urine and blood specimens were taken to evaluate for konzo and alternative etiologies. RESULTS: We identified 32 cases of konzo exclusively affecting children 6 to 14 years of age and predominantly females >14 years of age. Fourteen of 15 (93%) cases ≥15 years of age were female, 11 (73%) of whom were breastfeeding at the time of symptom onset. Cassava was the most commonly consumed food (median [range] 14 [4-21] times per week), while protein-rich foods were consumed <1 time per week for all cases. Of the 30 patients providing urine specimens, median thiocyanate level was 281 (interquartile range 149-522) µmol/L, and 73% of urine samples had thiocyanate levels >136 µmol/L, the 95th percentile of the US population in 2013 to 2014. CONCLUSION: This investigation revealed the first documented cases of konzo in Zambia, occurring in poor communities with diets high in cassava and low in protein, consistent with previous descriptions from neighboring countries.

Cholera Epidemic - Lusaka, Zambia, October 2017-May 2018.

On October 6, 2017, an outbreak of cholera was declared in Zambia after laboratory confirmation of Vibrio cholerae O1, biotype El Tor, serotype Ogawa, from stool specimens from two patients with acute watery diarrhea. The two patients had gone to a clinic in Lusaka, the capital city, on October 4. Cholera cases increased rapidly, from several hundred cases in early December 2017 to approximately 2,000 by early January 2018 (Figure). In collaboration with partners, the Zambia Ministry of Health (MoH) launched a multifaceted public health response that included increased chlorination of the Lusaka municipal water supply, provision of emergency water supplies, water quality monitoring and testing, enhanced surveillance, epidemiologic investigations, a cholera vaccination campaign, aggressive case management and health care worker training, and laboratory testing of clinical samples. In late December 2017, a number of water-related preventive actions were initiated, including increasing chlorine levels throughout the city's water distribution system and placing emergency tanks of chlorinated water in the most affected neighborhoods; cholera cases declined sharply in January 2018. During January 10-February 14, 2018, approximately 2 million doses of oral cholera vaccine were administered to Lusaka residents aged ≥1 year. However, in mid-March, heavy flooding and widespread water shortages occurred, leading to a resurgence of cholera. As of May 12, 2018, the outbreak had affected seven of the 10 provinces in Zambia, with 5,905 suspected cases and a case fatality rate (CFR) of 1.9%. Among the suspected cases, 5,414 (91.7%), including 98 deaths (CFR = 1.8%), occurred in Lusaka residents.

Human-animal anthrax outbreak in the Luangwa valley of Zambia in 2011.

There has been a reduction of incidences of anthrax in the developed countries but it is still a public health problem in the developing countries where communities live in interface areas with wildlife. An outbreak of anthrax in Hippopotamus amphibious was observed in Zambia. Following the death of hippopotamuses, suspected human cases were reported. The objective of this study was to isolate and confirm Bacillus anthracis and to determine the antimicrobial susceptibility for the management of the disease. Of the specimens collected, 29.4% (95% confidence interval [CI], 11.4-56.0) were from humans, 42.1% (95% CI, 21.1-66.0) were from hippopotamuses and 20.0% (95% CI, 6.61-44.3) from the soil were found to be positive were for B. anthracis. An antimicrobial susceptibility test revealed that all the isolates were found to be sensitive to the recommended antibiotics. The disease control was achieved by case management and by explaining to the communities that they should avoid contact with animals that die from unknown causes.

Safety and effectiveness of BufferGel and 0.5% PRO2000 gel for the prevention of HIV infection in women.

OBJECTIVE: To determine the safety and effectiveness of BufferGel and 0.5% PRO2000 microbicide gels for the prevention of male-to-female HIV transmission. DESIGN: Phase II/IIb, randomized, placebo-controlled trial with three double-blinded gel arms and an open-label no gel arm. METHODS: Study participants from Malawi, South Africa, Zambia, Zimbabwe, and the USA were instructed to apply study gel up to 1 h before each sex act and safety, sexual behavior, pregnancy, gel adherence, acceptability, and HIV serostatus were assessed during follow-up. RESULTS: The 3101 enrolled women were followed for an average of 20.4 months with 93.6% retention and 81.1% self-reported gel adherence. Adverse event rates were similar in all study arms. HIV incidence rates in the 0.5% PRO2000 gel, BufferGel, placebo gel, and no gel arms were 2.70, 4.14, 3.91, and 4.02 per 100 women-years, respectively. HIV incidence in the 0.5% PRO2000 gel arm was lower than the placebo gel arm (hazard ratio = 0.7, P = 0.10) and the no gel arm (hazard ratio = 0.67, P = 0.06). HIV incidence rates were similar in the BufferGel and both placebo gel (hazard ratio = 1.10, P = 0.63) and no gel control arms (hazard ratio = 1.05, P = 0.78). HIV incidence was similar in the placebo gel and no gel arms (hazard ratio = 0.97, P = 0.89). CONCLUSION: The 0.5% PRO2000 gel demonstrated a modest 30% reduction in HIV acquisition in women. However, these results were not statistically significant and subsequent findings from the Microbicide Development Programme (MDP) 301 trial have confirmed that 0.5% PRO2000 gel has little or no protective effect. BufferGel did not alter the risk of HIV infection. Both products were well tolerated.

HIV incidence rates and risk factors for urban women in Zambia: preparing for a microbicide clinical trial.

OBJECTIVES: A preparedness study was conducted to evaluate the suitability of sites and populations following the same study procedures intended for a larger scale microbicide efficacy trial. In the process the study evaluated human immunodeficiency virus (HIV) incidence, prevalence, and risk profiles for HIV-acquisition among young women in urban Zambia. METHODS: Women aged 16 to 49 years were screened for participation in the study that involved HIV/sexually transmitted infection testing and the assessment of sexual behavioral characteristics. Two hundred thirty-nine eligible women were enrolled and followed up for 12 months. RESULTS: Baseline HIV prevalence at screening was 38.7% (95% CI: 34.2%-43.3%). The highest age-specific prevalence of HIV was 54.1% (95% CI: 46.3%-61.8%) seen in women aged 26 to 34 years. HIV incidence was 2.6% per 100 woman years. Pregnancy rates were high at 17.4 per 100 woman years (95% CI: 12.2-24.1). CONCLUSION: It was concluded that our general population sample, characterized by high HIV prevalence and ongoing incidence rates despite receiving regular risk reduction counseling and free condoms qualifies for future microbicide studies.A microbicide preparedness study conducted in Lusaka, Zambia found high HIV prevalence and appreciable HIV incidence in a population of women in an urban setting.