John Vertefeuille

Cholera Surveillance during the Haiti Epidemic — The First 2 Years

BACKGROUND In October 2010, nearly 10 months after a devastating earthquake, Haiti was stricken by epidemic cholera. Within days after detection, the Ministry of Public Health and Population established a National Cholera Surveillance System (NCSS). METHODS The NCSS used a modified World Health Organization case definition for cholera that included acute watery diarrhea, with or without vomiting, in persons of all ages residing in an area in which at least one case of Vibrio cholerae O1 infection had been confirmed by culture. RESULTS Within 29 days after the first report, cases of V. cholerae O1 (serotype Ogawa, biotype El Tor) were confirmed in all 10 administrative departments (similar to states or provinces) in Haiti. Through October 20, 2012, the public health ministry reported 604,634 cases of infection, 329,697 hospitalizations, and 7436 deaths from cholera and isolated V. cholerae O1 from 1675 of 2703 stool specimens tested (62.0%). The cumulative attack rate was 5.1% at the end of the first year and 6.1% at the end of the second year. The cumulative case fatality rate consistently trended downward, reaching 1.2% at the close of year 2, with departmental cumulative rates ranging from 0.6% to 4.6% (median, 1.4%). Within 3 months after the start of the epidemic, the rolling 14-day case fatality rate was 1.0% and remained at or below this level with few, brief exceptions. Overall, the cholera epidemic in Haiti accounted for 57% of all cholera cases and 53% of all cholera deaths reported to the World Health Organization in 2010 and 58% of all cholera cases and 37% of all cholera deaths in 2011. CONCLUSIONS A review of NCSS data shows that during the first 2 years of the cholera epidemic in Haiti, the cumulative attack rate was 6.1%, with cases reported in all 10 departments. Within 3 months after the first case was reported, there was a downward trend in mortality, with a 14-day case fatality rate of 1.0% or less in most areas.

Lack of Evidence of Avian-to-Human Transmission of Avian Influenza A (H5N1) Virus among Poultry Workers, Kano, Nigeria, 2006

BACKGROUND In February 2006, poultry outbreaks of highly pathogenic avian influenza A (H5N1) virus were confirmed in Nigeria. A serosurvey was conducted to assess H5N1 transmission among poultry workers and laboratory workers in Nigeria. METHODS From 21 March through 3 April 2006, 295 poultry workers and 25 laboratory workers with suspected exposure to H5N1 virus were administered a questionnaire to assess H5N1 exposures, medical history, and health care utilization. A serum specimen was collected from participants to test for H5N1 neutralizing antibodies by microneutralization assay. RESULTS The 295 poultry workers reported a median of 14 days of exposure to suspected or confirmed H5N1-infected poultry without antiviral chemoprophylaxis and with minimal personal protective equipment. Among 25 laboratory workers, all handled poultry specimens with suspected H5N1 virus infection. All participants tested negative for H5N1 neutralizing antibodies. CONCLUSIONS Despite widespread exposure to poultry likely infected with H5N1 virus, no serological evidence of H5N1 virus infection was identified among participants. Continued surveillance for H5N1 cases in humans and further seroprevalence investigations are needed to assess the risk of avian-to-human transmission, given that H5N1 viruses continue to circulate and evolve among poultry.

Preparedness for highly pathogenic avian influenza pandemic in Africa.

Africa’s strategies for pandemic influenza must also strengthen overall public health capacity.

Laboratory-Confirmed Cholera and Rotavirus among Patients with Acute Diarrhea in Four Hospitals in Haiti, 2012–2013

An outbreak of cholera began in Haiti in October of 2010. To understand the progression of epidemic cholera in Haiti, in April of 2012, we initiated laboratory-enhanced surveillance for diarrheal disease in four Haitian hospitals in three departments. At each site, we sampled up to 10 hospitalized patients each week with acute watery diarrhea. We tested 1,616 specimens collected from April 2, 2012 to March 28, 2013; 1,030 (63.7%) specimens yielded Vibrio cholerae, 13 (0.8%) specimens yielded Shigella, 6 (0.4%) specimens yielded Salmonella, and 63 (3.9%) specimens tested positive for rotavirus. Additionally, 13.5% of children < 5 years old tested positive for rotavirus. Of 1,030 V. cholerae isolates, 1,020 (99.0%) isolates were serotype Ogawa, 9 (0.9%) isolates were serotype Inaba, and 1 isolate was non-toxigenic V. cholerae O139. During 1 year of surveillance, toxigenic cholera continued to be the main cause of acute diarrhea in hospitalized patients, and rotavirus was an important cause of diarrhea-related hospitalizations in children.

HIV counseling and testing and access-to-care needs of populations most-at-risk for HIV in Nigeria.

Abstract Mobile HIV counseling and testing (mHCT) is an effective tool to access hard-to-reach most-at-risk populations (MARPs), but identifying which populations are not accessing services is often a challenge. We compared correlates of human immunodeficiency virus (HIV) infection and awareness of HIV care services among populations tested through mHCT and at testing facilities in Nigeria. Participants in a cross-sectional study completed a questionnaire and HCT between May 2005 and March 2010. Of 27,586 total participants, 26.7% had been previously tested for HIV; among mHCT clients, 14.7% had previously been tested. HIV prevalence ranged from 6.6% among those tested through a facility to 50.4% among brothel-based sex workers tested by mHCT. Among mHCT participants aged 18–24, women were nine times more likely to be infected than men. Women aged 18–24 were also less likely than their male counterparts to know that there were medicines available to treat HIV (63.2 vs. 68.1%; p=0.03). After controlling for gender, age, and other risk factors, those with current genital ulcer disease were more likely to be HIV-infected (ORmHCT=1.65, 1.31–2.09; ORfacility=1.71, 1.37–2.14), while those previously tested were less likely to be HIV-infected (ORmHCT=0.75, 0.64–0.88; ORfacility=0.27, 0.24–0.31). There is an urgent need to promote strategies to identify those who are HIV-infected within MARPs, particularly young women, and to educate and inform them about availability of HIV testing and care services. mHCT, ideally coupled with sexually transmitted infection management, may help to ensure that MARPs access HIV prevention support, and if infected, access care, and treatment.

Characterization of Acute HIV-1 Infection in High-Risk Nigerian Populations

BACKGROUND Acute phase of human immunodeficiency virus (HIV) infection (AHI) may account for a significant proportion of HIV-1 transmission. We identified and characterized individuals in Nigeria with AHI. METHODS Individuals were tested using a combination of rapid HIV testing in mobile units and laboratory-based specimen pooling for nucleic acid amplification testing. Genome sequences were characterized. A linear segmented regression model was fit to serial viral load (VL) measurements to characterize early VL profiles. RESULTS Sixteen AHIs were identified from 28 655 persons screened. Specimens were genotyped: 7 (43.8%) were CRF02_AG, 6 (37.5%) were subtype G, 1 (6.3%) was CRF06_cpx, and 2 (12.5%) were unique recombinant forms. No antiretroviral resistance mutations were detected. The mean duration of high VL burden from peak to nadir was 76 days (95% confidence interval [CI], 58-93 days), and the mean rate of viremic control was -0.66 log(10) VL per month. The mean VL at set-point was 4.5 log(10) copies/mL (95% CI, 3.9-5.1 log(10) copies/mL). CONCLUSIONS This study is the first to characterize AHI among Nigerians identified as HIV infected before seroconversion who would be otherwise missed by conventional HIV testing. Infections by HIV subtypes in Nigeria exhibit long periods of high viral burden, which can contribute to increased transmissibility.

Progress Toward Poliomyelitis Eradication--Nigeria, January 2014-July 2015.

Since the 1988 launch of global poliomyelitis eradication efforts, four of the six World Health Organization (WHO) regions have been certified polio-free. Nigeria is one of only three countries, along with Afghanistan and Pakistan, where transmission of wild poliovirus (WPV) has never been interrupted. During 2003-2013, northern Nigeria served as a reservoir for WPV reintroduction into 26 previously polio-free countries. In 2012, the Nigerian government launched a national polio eradication emergency plan to intensify efforts to interrupt WPV transmission. This report describes polio eradication activities and progress in Nigeria during January 2014-July 2015 and updates previous reports. No WPV cases have been reported to date in 2015, compared with a total of six cases reported during 2014. Onset of paralysis in the latest reported WPV type 1 (WPV1) case was July 24, 2014. Only one case of circulating vaccine-derived poliovirus type 2 (cVDPV2) has been reported to date in 2015, compared with 20 cVDPV2 cases during the same period in 2014. Pending final laboratory testing of 218 remaining specimens of 16,617 specimens collected since January 2015, Nigeria could be removed from the WHO list of polio-endemic countries in September 2015. Major remaining challenges to the national polio eradication program include sustaining political support and program funding in the absence of active WPV transmission, maintaining high levels of population immunity in hard-to-reach areas, and accessing children in security-compromised areas of the northeastern states.

Progress Toward Poliomyelitis Eradication in Nigeria

BACKGROUND Transmission of wild poliovirus (WPV) has never been interrupted in Afghanistan, Pakistan, and Nigeria. Since 2003, infections with WPV of Nigerian origin have been detected in 25 polio-free countries. In 2012, the Nigerian government created an emergency operations center and implemented a national emergency action plan to eradicate polio. The 2013 revision of this plan prioritized (1) improving the quality of supplemental immunization activities (SIAs), (2) implementing strategies to reach underserved populations, (3) adopting special approaches in security-compromised areas, (4) improving outbreak response, (5) enhancing routine immunization and activities implemented between SIAs, and (6) strengthening surveillance. This report summarizes implementation of these activities during a period of unprecedented insecurity and violence, including the killing of health workers and the onset of a state of emergency in the northeast zone. METHODS This report reviews management strategies, innovations, trends in case counts, vaccination and social mobilization activities, and surveillance and monitoring data to assess progress in polio eradication in Nigeria. RESULTS Nigeria has made significant improvements in the management of polio eradication initiative (pei) activities with marked improvement in the quality of SIAs, as measured by lot quality assurance sampling (LQAS). Comparing results from February 2012 with results from December 2013, the proportion of local government areas (LGAs) conducting LQAS in the 11 high-risk states at the ≥90% pass/fail threshold increased from 7% to 42%, and the proportion at the 80%-89% threshold increased from 9% to 30%. During January-December 2013, 53 polio cases were reported from 26 LGAs in 9 states in Nigeria, compared with 122 cases reported from 13 states in 2012. No cases of WPV type 3 infection have been reported since November 2012. In 2013, no polio cases due to any poliovirus type were detected in the northwest sanctuaries of Nigeria. In the second half of 2013, WPV transmission was restricted to Kano, Borno, Bauchi, and Taraba states. Despite considerable progress, 24 LGAs in 2012 and 7 LGAs in 2013 reported ≥2 cases, and WPV continued to circulate in 8 LGAs that had cases in 2012. Campaign activities were negatively impacted by insecurity and violence in Borno and Kano states. CONCLUSIONS Efforts to interrupt transmission remain impeded by poor SIA implementation in localized areas, anti-polio vaccine sentiment, and limited access to vaccinate children because of insecurity. Sustained improvement in SIA quality, surveillance, and outbreak response and special strategies in security-compromised areas are needed to interrupt WPV transmission in 2014.

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.

Evaluation of an External Quality Assessment Program for HIV Testing in Haiti, 2006–2011

OBJECTIVES To evaluate an external quality assessment (EQA) program for human immunodeficiency virus (HIV) rapid diagnostics testing by the Haitian National Public Health Laboratory (French acronym: LNSP). Acceptable performance was defined as any proficiency testing (PT) score more than 80%. METHODS The PT database was reviewed and analyzed to assess the testing performance of the participating laboratories and the impact of the program over time. A total of 242 laboratories participated in the EQA program from 2006 through 2011; participation increased from 70 laboratories in 2006 to 159 in 2011. RESULTS In 2006, 49 (70%) laboratories had a PT score of 80% or above; by 2011, 145 (97.5%) laboratories were proficient (P < .05). CONCLUSIONS The EQA program for HIV testing ensures quality of testing and allowed the LNSP to document improvements in the quality of HIV rapid testing over time.