Last data update: May 06, 2024. (Total: 46732 publications since 2009)
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Trends in SARS-CoV-2 seroprevalence among pregnant women attending first antenatal care visits in Zambia: A repeated cross-sectional survey, 2021-2022
Heilmann E , Tembo T , Fwoloshi S , Kabamba B , Chilambe F , Kalenga K , Siwingwa M , Mulube C , Seffren V , Bolton-Moore C , Simwanza J , Yingst S , Yadav R , Rogier E , Auld AF , Agolory S , Kapina M , Gutman JR , Savory T , Kangale C , Mulenga LB , Sikazwe I , Hines JZ . PLOS Glob Public Health 2024 4 (4) e0003073 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. |
Contribution of PEPFAR-supported HIV and TB molecular diagnostic networks to COVID-19 testing preparedness in 16 countries
Romano ER , Sleeman K , Hall-Eidson P , Zeh C , Bhairavabhotla R , Zhang G , Adhikari A , Alemnji G , Cardo YR , Pinheiro A , Pocongo B , Eno LT , Shang JD , Ndongmo CB , Rosario H , Moreno O , DeLen LAC , Fonjungo P , Kabwe C , Ahuke-Mundeke S , Gama D , Dlamini S , Maphalala G , Abreha T , Purfield A , Gebrehiwot YT , Desalegn DM , Basiye F , Mwangi J , Bowen N , Mengistu Y , Lecher S , Kampira E , Kaba M , Bitilinyu-Bangoh J , Masamha G , Viegas SO , Beard RS , vanRooyen G , Shiningavamwe AN , I JM , Iriemenam NC , Mba N , Okoi C , Katoro J , Kenyi DL , Bior BK , Mwangi C , Nabadda S , Kaleebu P , Yingst SL , Chikwanda P , Veri L , Simbi R , Alexander H . Emerg Infect Dis 2022 28 (13) S59-s68 The US President's Emergency Plan for AIDS Relief (PEPFAR) supports molecular HIV and tuberculosis diagnostic networks and information management systems in low- and middle-income countries. We describe how national programs leveraged these PEPFAR-supported laboratory resources for SARS-CoV-2 testing during the COVID-19 pandemic. We sent a spreadsheet template consisting of 46 indicators for assessing the use of PEPFAR-supported diagnostic networks for COVID-19 pandemic response activities during April 1, 2020, to March 31, 2021, to 27 PEPFAR-supported countries or regions. A total of 109 PEPFAR-supported centralized HIV viral load and early infant diagnosis laboratories and 138 decentralized HIV and TB sites reported performing SARS-CoV-2 testing in 16 countries. Together, these sites contributed to >3.4 million SARS-CoV-2 tests during the 1-year period. Our findings illustrate that PEPFAR-supported diagnostic networks provided a wide range of resources to respond to emergency COVID-19 diagnostic testing in 16 low- and middle-income countries. |
Severe acute respiratory coronavirus virus 2 (SARS-CoV-2) outbreaks in nursing homes involving residents who had completed a primary coronavirus disease 2019 (COVID-19) vaccine series-13 US jurisdictions, July-November 2021.
Wyatt Wilson W , Keaton AA , Ochoa LG , Hatfield KM , Gable P , Walblay KA , Teran RA , Shea M , Khan U , Stringer G , Colletti JG , Grogan EM , Calabrese C , Hennenfent A , Perlmutter R , Janiszewski KA , Kamal-Ahmed I , Strand K , Berns E , MacFarquhar J , Linder M , Tran DJ , Kopp P , Walker RM , Ess R , Read JS , Yingst C , Baggs J , Jernigan JA , Kallen A , Hunter JC . Infect Control Hosp Epidemiol 2023 44 (6) 1-5 Among nursing home outbreaks of coronavirus disease 2019 (COVID-19) with ≥3 breakthrough infections when the predominant severe acute respiratory coronavirus virus 2 (SARS-CoV-2) variant circulating was the SARS-CoV-2 δ (delta) variant, fully vaccinated residents were 28% less likely to be infected than were unvaccinated residents. Once infected, they had approximately half the risk for all-cause hospitalization and all-cause death compared with unvaccinated infected residents. |
SARS-CoV-2 Prevalence among Outpatients during Community Transmission, Zambia, July 2020.
Hines JZ , Fwoloshi S , Kampamba D , Barradas DT , Banda D , Zulu JE , Wolkon A , Yingst S , Boyd MA , Siwingwa M , Chirwa L , Kapina M , Sinyange N , Mukonka V , Malama K , Mulenga LB , Agolory S . Emerg Infect Dis 2021 27 (8) 2166-2168 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 (SARS-CoV-2) among Health Care Workers-Zambia, July 2020.
Fwoloshi S , Hines JZ , Barradas DT , Yingst S , Siwingwa M , Chirwa L , Zulu JE , Banda D , Wolkon A , Nikoi KI , Chirwa B , Kampamba D , Shibemba A , Sivile S , Zyambo KD , Chanda D , Mupeta F , Kapina M , Sinyange N , Kapata N , Zulu PM , Makupe A , Mweemba A , Mbewe N , Ziko L , Mukonka V , Mulenga LB , Malama K , Agolory S . Clin Infect Dis 2021 73 (6) e1321-e1328 INTRODUCTION: Healthcare workers (HCWs) in Zambia have become infected with SARS-CoV-2, the virus that causes coronavirus disease (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 twenty health facilities in six 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 performed. RESULTS: In total, 660 HCWs participated in the study, with 450 (68.2%) providing nasopharyngeal swab for PCR and 575 (87.1%) providing a blood specimen for ELISA. Sixty-six percent of participants were females and the median age was 31.5 years (interquartile range 26.2-39.8 years). 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 0.5%-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 accessing 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.
Mulenga LB , Hines JZ , Fwoloshi S , Chirwa L , Siwingwa M , Yingst S , Wolkon A , Barradas DT , Favaloro J , Zulu JE , Banda D , Nikoi KI , Kampamba D , Banda N , Chilopa B , Hanunka B , Stevens TL Jr , Shibemba A , Mwale C , Sivile S , Zyambo KD , Makupe A , Kapina M , Mweemba A , Sinyange N , Kapata N , Zulu PM , Chanda D , Mupeta F , Chilufya C , Mukonka V , Agolory S , Malama K . Lancet Glob Health 2021 9 (6) e773-e781 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. |
Detection of B.1.351 SARS-CoV-2 Variant Strain - Zambia, December 2020.
Mwenda M , Saasa N , Sinyange N , Busby G , Chipimo PJ , Hendry J , Kapona O , Yingst S , Hines JZ , Minchella P , Simulundu E , Changula K , Nalubamba KS , Sawa H , Kajihara M , Yamagishi J , Kapin'a M , Kapata N , Fwoloshi S , Zulu P , Mulenga LB , Agolory S , Mukonka V , Bridges DJ . MMWR Morb Mortal Wkly Rep 2021 70 (8) 280-282 The first laboratory-confirmed cases of coronavirus disease 2019 (COVID-19), the illness caused by SARS-CoV-2, in Zambia were detected in March 2020 (1). Beginning in July, the number of confirmed cases began to increase rapidly, first peaking during July-August, and then declining in September and October (Figure). After 3 months of relatively low case counts, COVID-19 cases began rapidly rising throughout the country in mid-December. On December 18, 2020, South Africa published the genome of a SARS-CoV-2 variant strain with several mutations that affect the spike protein (2). The variant included a mutation (N501Y) associated with increased transmissibility.(†)(,)(§) SARS-CoV-2 lineages with this mutation have rapidly expanded geographically.(¶)(,)** The variant strain (PANGO [Phylogenetic Assignment of Named Global Outbreak] lineage B.1.351(††)) was first detected in the Eastern Cape Province of South Africa from specimens collected in early August, spread within South Africa, and appears to have displaced the majority of other SARS-CoV-2 lineages circulating in that country (2). As of January 10, 2021, eight countries had reported cases with the B.1.351 variant. In Zambia, the average number of daily confirmed COVID-19 cases increased 16-fold, from 44 cases during December 1-10 to 700 during January 1-10, after detection of the B.1.351 variant in specimens collected during December 16-23. Zambia is a southern African country that shares substantial commerce and tourism linkages with South Africa, which might have contributed to the transmission of the B.1.351 variant between the two countries. |
First 100 Persons with COVID-19 - Zambia, March 18-April 28, 2020.
Chipimo PJ , Barradas DT , Kayeyi N , Zulu PM , Muzala K , Mazaba ML , Hamoonga R , Musonda K , Monze M , Kapata N , Sinyange N , Simwaba D , Kapaya F , Mulenga L , Chanda D , Malambo W , Ngosa W , Hines J , Yingst S , Agolory S , Mukonka V . MMWR Morb Mortal Wkly Rep 2020 69 (42) 1547-1548 Zambia is a landlocked, lower-middle income country in southern Africa, with a population of 17 million (1). The first known cases of coronavirus disease 2019 (COVID-19) in Zambia occurred in a married couple who had traveled to France and were subject to port-of-entry surveillance and subsequent remote monitoring of travelers with a history of international travel for 14 days after arrival. They were identified as having suspected cases on March 18, 2020, and tested for COVID-19 after developing respiratory symptoms during the 14-day monitoring period. In March 2020, the Zambia National Public Health Institute (ZNPHI) defined a suspected case of COVID-19 as 1) an acute respiratory illness in a person with a history of international travel during the 14 days preceding symptom onset; or 2) acute respiratory illness in a person with a history of contact with a person with laboratory-confirmed COVID-19 in the 14 days preceding symptom onset; or 3) severe acute respiratory illness requiring hospitalization; or 4) being a household or close contact of a patient with laboratory-confirmed COVID-19. This definition was adapted from World Health Organization (WHO) interim guidance issued March 20, 2020, on global surveillance for COVID-19 (2) to also include asymptomatic contacts of persons with confirmed COVID-19. Persons with suspected COVID-19 were identified through various mechanisms, including port-of-entry surveillance, contact tracing, health care worker (HCW) testing, facility-based inpatient screening, community-based screening, and calls from the public into a national hotline administered by the Disaster Management and Mitigation Unit and ZNPHI. Port-of-entry surveillance included an arrival screen consisting of a temperature scan, report of symptoms during the preceding 14 days, and collection of a history of travel and contact with persons with confirmed COVID-19 in the 14 days before arrival in Zambia, followed by daily remote telephone monitoring for 14 days. Travelers were tested for SARS-CoV-2, the virus that causes COVID-19, if they were symptomatic upon arrival or developed symptoms during the 14-day monitoring period. Persons with suspected COVID-19 were tested as soon as possible after evaluation for respiratory symptoms or within 7 days of last known exposure (i.e., travel or contact with a confirmed case). All COVID-19 diagnoses were confirmed using real-time reverse transcription-polymerase chain reaction (RT-PCR) testing (SARS-CoV-2 Nucleic Acid Detection Kit, Maccura) of nasopharyngeal specimens; all patients with confirmed COVID-19 were admitted into institutional isolation at the time of laboratory confirmation, which was generally within 36 hours. COVID-19 patients were deemed recovered and released from isolation after two consecutive PCR-negative test results ≥24 hours apart. A Ministry of Health memorandum was released on April 13, 2020, mandating testing in public facilities of 1) all persons admitted to medical and pediatric wards regardless of symptoms; 2) all patients being admitted to surgical and obstetric wards, regardless of symptoms; 3) any outpatient with fever, cough, or shortness of breath; and 4) any facility or community death in a person with respiratory symptoms, and 5) biweekly screening of all HCWs in isolation centers and health facilities where persons with COVID-19 had been evaluated. This report describes the first 100 COVID-19 cases reported in Zambia, during March 18-April 28, 2020. |
A high diversity of Eurasian lineage low pathogenicity avian influenza A viruses circulate among wild birds sampled in Egypt
Gerloff NA , Jones J , Simpson N , Balish A , Elbadry MA , Baghat V , Rusev I , de Mattos CC , de Mattos CA , Zonkle LE , Kis Z , Davis CT , Yingst S , Cornelius C , Soliman A , Mohareb E , Klimov A , Donis RO . PLoS One 2013 8 (7) e68522 Surveillance for influenza A viruses in wild birds has increased substantially as part of efforts to control the global movement of highly pathogenic avian influenza A (H5N1) virus. Studies conducted in Egypt from 2003 to 2007 to monitor birds for H5N1 identified multiple subtypes of low pathogenicity avian influenza A viruses isolated primarily from migratory waterfowl collected in the Nile Delta. Phylogenetic analysis of 28 viral genomes was performed to estimate their nearest ancestors and identify possible reassortants. Migratory flyway patterns were included in the analysis to assess gene flow between overlapping flyways. Overall, the viruses were most closely related to Eurasian, African and/or Central Asian lineage low pathogenicity viruses and belonged to 15 different subtypes. A subset of the internal genes seemed to originate from specific flyways (Black Sea-Mediterranean, East African-West Asian). The remaining genes were derived from a mixture of viruses broadly distributed across as many as 4 different flyways suggesting the importance of the Nile Delta for virus dispersal. Molecular clock date estimates suggested that the time to the nearest common ancestor of all viruses analyzed ranged from 5 to 10 years, indicating frequent genetic exchange with viruses sampled elsewhere. The intersection of multiple migratory bird flyways and the resulting diversity of influenza virus gene lineages in the Nile Delta create conditions favoring reassortment, as evident from the gene constellations identified by this study. In conclusion, we present for the first time a comprehensive phylogenetic analysis of full genome sequences from low pathogenic avian influenza viruses circulating in Egypt, underscoring the significance of the region for viral reassortment and the potential emergence of novel avian influenza A viruses, as well as representing a highly diverse influenza A virus gene pool that merits continued monitoring. |
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