Cholera outbreak in some communities in North-East Nigeria, 2019: an unmatched case-control study.

BACKGROUND: Cholera, a diarrheal disease caused by the bacterium Vibrio cholerae, transmitted through fecal contamination of water or food remains an ever-present risk in many countries, especially where water supply, sanitation, food safety, and hygiene are inadequate. A cholera outbreak was reported in Bauchi State, North-eastern Nigeria. We investigated the outbreak to determine the extent and assess risk factors associated with the outbreak. METHODS: We conducted a descriptive analysis of suspected cholera cases to determine the fatality rate (CFR), attack rate (AR), and trends/patterns of the outbreak. We also conducted a 1:2 unmatched case-control study to assess risk factors amongst 110 confirmed cases and 220 uninfected individuals (controls). We defined a suspected case as any person > 5 years with acute watery diarrhea with/without vomiting; a confirmed case as any suspected case in which there was laboratory isolation of Vibrio cholerae O1 or O139 from the stool while control was any uninfected individual with close contact (same household) with a confirmed case. Children under 5 were not included in the case definition however, samples from this age group were collected where such symptoms had occurred and line-listed separately. Data were collected with an interviewer-administered questionnaire and analyzed using Epi-info and Microsoft excel for frequencies, proportions, bivariate and multivariate analysis at a 95% confidence interval. RESULTS: A total of 9725 cases were line-listed with a CFR of 0.3% in the state. Dass LGA had the highest CFR (14.3%) while Bauchi LGA recorded the highest AR of 1,830 cases per 100,000 persons. Factors significantly associated with cholera infection were attending social gatherings (aOR = 2.04, 95% CI = 1.16-3.59) and drinking unsafe water (aOR = 1.74, 95% CI = 1.07-2.83). CONCLUSION: Attending social gatherings and drinking unsafe water were risk factors for cholera infection. Public health actions included chlorination of wells and distribution of water guard (1% chlorine solution) bottles to households and public education on cholera prevention. We recommend the provision of safe drinking water by the government as well as improved sanitary and hygienic conditions for citizens of the state.

Evaluation of the Measles Surveillance System in Kaduna State, Nigeria (2010-2012).

OBJECTIVE: To evaluate the case-based measles surveillance system in Kaduna State of Nigeria and identify gaps in its operation. INTRODUCTION: In Africa, approximately 13 million cases, 650,000 deaths due to measles occur annually, with sub-Saharan Africa having the highest morbidity and mortality. Measles infection is endemic in Nigeria and has been documented to occur all year round, despite high measles routine and supplemental immunization coverage. The frequent outbreaks of measles in Kaduna State prompted the need for the evaluation of the measles case-based surveillance system. METHODS: We interviewed stakeholders and conducted a retrospective record review of the measles case-based surveillance data from 2010 - 2012 and adapted the 2001 CDC guidelines on surveillance evaluation and the Framework for Evaluating Public Health Surveillance Systems for Early Detection of Outbreaks, to assess the systems usefulness, representativeness, timeliness, stability, acceptability and data quality. We calculated the annualized detection rate of measles and non-measles febrile rash, proportion of available results, proportion of LGAs (Districts) that investigated at least one case with blood, proportion of cases that were IgM positive and the incidence of measles. We compared the results with WHO(2004) recommended performance indicators to determine the quality and effectiveness of measles surveillance system. RESULTS: According to the Stakeholders, the case-based surveillance system was useful and acceptable. Median interval between specimen collection and release of result was 7days (1 - 25 days) in 2010, 38 days (Range: 16 - 109 days) in 2011 and 11 days (Range: 1 - 105 days) in 2012. The annualized detection rate of measles rash in 2010 was 2.1 (target: 32), 1.0 (target: 32) in 2011 and 1.4 (target: 32) in 2012. The annualized detection rate of non-measles febrile rash in 2010 was 2.1 (target: 32), 0.6 (target: 32) in 2011 and 0.8 (target: 32) in 2012. Case definitions are simple and understood by all the operators. CONCLUSION: This evaluation showed that the surveillance system was still useful. Also, the efficiency and effectiveness of the laboratory component as captured by the "median interval between specimen collection and the release of results improved in 2010 and 2012 compared to 2011. However, there was a progressive decline in the timeliness and completeness of weekly reports in the years under review.

Ebola virus disease - gaps in knowledge and practice among healthcare workers in Lagos, August 2014.

OBJECTIVE: Healthcare workers (HCWs) play pivotal roles in outbreak responses. Ebola virus disease (EVD) outbreak spread to Lagos, Nigeria, in July 2014, infecting 11 HCWs (case fatality rate of 45%). This study was conducted during the outbreak to assess HCWs' EVD-related knowledge and practices. METHODS: A health facility-based cross-sectional study was conducted among HCWs across Lagos State using stratified sampling technique. An interviewer-administered questionnaire was administered to elicit respondents' socio-demographic characteristics, knowledge and practices. A checklist assessing health facility's level of preparedness and HCWs' EVD-related training was employed. HCWs' knowledge and practices were scored and classified as either good or poor. Multivariate analysis was performed with confidence interval set at 95%. RESULTS: A total of 112 health facilities with 637 HCWs were recruited. Mean age of respondents was 40.1 ± 10.9 years. Overall, 72.5% had good knowledge; doctors knew most. However, only 4.6% of HCWs reported good practices. 16.6% reported having been trained in identifying suspected EVD patient(s); 12.2% had a triaging area for febrile patients in their facilities. Higher proportions of HCWs with good knowledge and training reported good practices. HCWs with EVD-related training were three times more likely to adopt good practices. CONCLUSION: Lagos State HCWs had good knowledge of EVD without a corresponding level of good practices. Training was a predictor of good practices.

Use of group quarantine in Ebola control - Nigeria, 2014.

On July 20, 2014, the first known case of Ebola virus disease (Ebola) in Nigeria, in a traveler from Liberia, led to an outbreak that was successfully curtailed with infection control, contact tracing, isolation, and quarantine measures coordinated through an incident management system. During this outbreak, most contacts underwent home monitoring, which included instructions to stay home or to avoid crowded areas if staying home was not possible. However, for five contacts with high-risk exposures, group quarantine in an observation unit was preferred because the five had crowded home environments or occupations that could have resulted in a large number of community exposures if they developed Ebola.

Polio eradication in Nigeria and the role of the National Stop Transmission of Polio program, 2012-2013.

To strengthen the Nigeria polio eradication program at the operational level, the National Stop Transmission of Polio (N-STOP) program was established in July 2012 as a collaborative effort of the National Primary Health Care Development Agency, the Nigerian Field Epidemiology and Laboratory Training Program, and the US Centers for Disease Control and Prevention. Since its inception, N-STOP has recruited and trained 125 full-time staff, 50 residents in training, and 50 ad hoc officers. N-STOP officers, working at national, state, and district levels, have conducted enumeration outreaches in 46,437 nomadic and hard-to-reach settlements in 253 districts of 19 states, supported supplementary immunization activities in 236 districts, and strengthened routine immunization in 100 districts. Officers have also conducted surveillance assessments, outbreak response, and applied research as needs evolved. The N-STOP program has successfully enhanced Global Polio Eradication Initiative partnerships and outreach in Nigeria, providing an accessible, flexible, and culturally competent technical workforce at the front lines of public health. N-STOP will continue to respond to polio eradication program needs and remain a model for other healthcare initiatives in Nigeria and elsewhere.

Outreach to underserved communities in northern Nigeria, 2012-2013.

BACKGROUND: Persistent wild poliovirus transmission in Nigeria constitutes a major obstacle to global polio eradication. In August 2012, the Nigerian national polio program implemented a strategy to conduct outreach to underserved communities within the context of the country's polio emergency action plans. METHODS: A standard operating procedure (SOP) for outreach to underserved communities was developed and included in the national guidelines for management of supplemental immunization activities (SIAs). The SOP included the following key elements: (1) community engagement meetings, (2) training of field teams, (3) field work, and (4) acute flaccid paralysis surveillance. RESULTS: Of the 46,437 settlements visited and enumerated during the outreach activities, 8607 (19%) reported that vaccination teams did not visit their settlements during prior SIAs, and 5112 (11.0%) reported never having been visited by polio vaccination teams. Fifty-two percent of enumerated settlements (23,944) were not found in the existing microplan used for the immediate past SIAs. CONCLUSIONS: During a year of outreach to >45,000 scattered, nomadic, and border settlements, approximately 1 in 5 identified were missed in the immediately preceding SIAs. These missed settlements housed a large number of previously unvaccinated children and potentially served as reservoirs for persistent wild poliovirus transmission in Nigeria.

Molecular detection and characterization of tick-borne pathogens in dogs and ticks from Nigeria.

BACKGROUND: Only limited information is currently available on the prevalence of vector borne and zoonotic pathogens in dogs and ticks in Nigeria. The aim of this study was to use molecular techniques to detect and characterize vector borne pathogens in dogs and ticks from Nigeria. METHODOLOGY/PRINCIPAL FINDINGS: Blood samples and ticks (Rhipicephalus sanguineus, Rhipicephalus turanicus and Heamaphysalis leachi) collected from 181 dogs from Nigeria were molecularly screened for human and animal vector-borne pathogens by PCR and sequencing. DNA of Hepatozoon canis (41.4%), Ehrlichia canis (12.7%), Rickettsia spp. (8.8%), Babesia rossi (6.6%), Anaplasma platys (6.6%), Babesia vogeli (0.6%) and Theileria sp. (0.6%) was detected in the blood samples. DNA of E. canis (23.7%), H. canis (21.1%), Rickettsia spp. (10.5%), Candidatus Neoehrlichia mikurensis (5.3%) and A. platys (1.9%) was detected in 258 ticks collected from 42 of the 181 dogs. Co- infections with two pathogens were present in 37% of the dogs examined and one dog was co-infected with 3 pathogens. DNA of Rickettsia conorii israelensis was detected in one dog and Rhipicephalus sanguineus tick. DNA of another human pathogen, Candidatus N. mikurensis was detected in Rhipicephalus sanguineus and Heamaphysalis leachi ticks, and is the first description of Candidatus N. mikurensis in Africa. The Theileria sp. DNA detected in a local dog in this study had 98% sequence identity to Theileria ovis from sheep. CONCLUSIONS/SIGNIFICANCE: The results of this study indicate that human and animal pathogens are abundant in dogs and their ticks in Nigeria and portray the potential high risk of human exposure to infection with these agents.