Cholera epidemic in Yemen, 2016-18: an analysis of surveillance data.

BACKGROUND: In war-torn Yemen, reports of confirmed cholera started in late September, 2016. The disease continues to plague Yemen today in what has become the largest documented cholera epidemic of modern times. We aimed to describe the key epidemiological features of this epidemic, including the drivers of cholera transmission during the outbreak. METHODS: The Yemen Health Authorities set up a national cholera surveillance system to collect information on suspected cholera cases presenting at health facilities. Individual variables included symptom onset date, age, severity of dehydration, and rapid diagnostic test result. Suspected cholera cases were confirmed by culture, and a subset of samples had additional phenotypic and genotypic analysis. We first conducted descriptive analyses at national and governorate levels. We divided the epidemic into three time periods: the first wave (Sept 28, 2016, to April 23, 2017), the increasing phase of the second wave (April 24, 2017, to July 2, 2017), and the decreasing phase of the second wave (July 3, 2017, to March 12, 2018). We reconstructed the changes in cholera transmission over time by estimating the instantaneous reproduction number, Rt. Finally, we estimated the association between rainfall and the daily cholera incidence during the increasing phase of the second epidemic wave by fitting a spatiotemporal regression model. FINDINGS: From Sept 28, 2016, to March 12, 2018, 1 103 683 suspected cholera cases (attack rate 3·69%) and 2385 deaths (case fatality risk 0·22%) were reported countrywide. The epidemic consisted of two distinct waves with a surge in transmission in May, 2017, corresponding to a median Rt of more than 2 in 13 of 23 governorates. Microbiological analyses suggested that the same Vibrio cholerae O1 Ogawa strain circulated in both waves. We found a positive, non-linear, association between weekly rainfall and suspected cholera incidence in the following 10 days; the relative risk of cholera after a weekly rainfall of 25 mm was 1·42 (95% CI 1·31-1·55) compared with a week without rain. INTERPRETATION: Our analysis suggests that the small first cholera epidemic wave seeded cholera across Yemen during the dry season. When the rains returned in April, 2017, they triggered widespread cholera transmission that led to the large second wave. These results suggest that cholera could resurge during the ongoing 2018 rainy season if transmission remains active. Therefore, health authorities and partners should immediately enhance current control efforts to mitigate the risk of a new cholera epidemic wave in Yemen. FUNDING: Health Authorities of Yemen, WHO, and Médecins Sans Frontières.

Measuring functioning and disability after a disaster: results from the typhoon Haiyan/Yolanda-affected areas of the Philippines.

The most commonly reported data after natural disasters are the number of deceased and displaced and the structural and economic damage, whereas disability data are often lacking. Our study assessed disability among the survivors of the Haiyan/Yolanda typhoon that struck Philippines in 2013 and is aimed to identify which context-level variables are associated with higher disability. We used a cross-sectional design and administered a household questionnaire, an individual sociodemographic questionnaire, and the WHODAS 2.0 to 1982 adults. Logistic regression analysis was carried out to address the degree to which demographic variables, effects of the typhoon, individual health state, and rural or urban residence were associated with higher disability. Those aged above 65, employed individuals, students, those not living in their households, and those with one or more health condition or rating their own as health moderate or very poor had higher likelihood of having severe disability. Survivors living in rural contexts and those who received tools/materials to repair their houses were less likely to have higher disability. This study outlines that disability can and should be used as an indicator in surveys after emergencies to identify the most vulnerable groups, thus guiding policies, reconstruction strategies, and health and social interventions.

Disease eradication, elimination and control: the need for accurate and consistent usage.

This article seeks to clarify the terminology associated with disease control, elimination and eradication programmes. There are several global activities under way, which are initiated and guided by resolutions of the World Health Assembly. Scrutiny of the feasibility of achieving eradication goals by bodies such as the International Task Force for Disease Eradication has identified diseases that could be eradicated. The criteria for this attribution as eradicable, the definitions guiding policy, and examples of programmes and strategies are provided here. This article pleads for scientific, health policy and editorial communities to be more consistent in the use of the terms control, elimination and eradication, and to adhere to published definitions.

Ensuring supplies of quality diethylcarbamazine citrate (DEC).

In 1997, the World Health Organization (WHO) made a commitment to eliminate lymphatic filariasis. The WHO Global Program to Eliminate Lymphatic Filariasis (WHO-FIL) needed a reliable supply of diethylcarbamazine citrate (DEC) of known acceptable quality at an affordable price, so in August 1999, it started the DEC Project. Today's standards required development of a modern stability-indicating assay method for DEC and for DEC tablet dissolution. ADD Advanced Drug Delivery Technologies (Switzerland) developed a high-pressure liquid chromatography assay, which was independently validated and is in the United States Pharmacopoeia 25 (2002). After a global search, the project found that almost all existing and potential DEC active pharmaceutical ingredient (API) and tablet manufacturers are in low-income countries. The project constructed an audit team to conduct on-site audits to assess good manufacturing practices according to European Union standards. National/state inspectors accompany the audit team. The team prequalified one DEC API manufacturer and three DEC tablet manufacturers. The project plans to increase the number of prequalified DEC manufacturers. Now, WHO-FIL only purchases from prequalified manufacturers. Consolidation of several national program DEC requirements into a limited international competitive bid reduced the price for DEC tablets between 30% and 45%, compared to previous small-scale WHO purchases.

Dracunculiasis (Guinea worm disease) and the eradication initiative.

Dracunculiasis, also known as guinea worm disease, is caused by the large female of the nematode Dracunculus medinensis, which emerges painfully and slowly from the skin, usually on the lower limbs. The disease can infect animals, and sustainable animal cycles occur in North America and Central Asia but do not act as reservoirs of human infection. The disease is endemic across the Sahel belt of Africa from Mauritania to Ethiopia, having been eliminated from Asia and some African countries. It has a significant socioeconomic impact because of the temporary disability that it causes. Dracunculiasis is exclusively caught from drinking water, usually from ponds. A campaign to eradicate the disease was launched in the 1980s and has made significant progress. The strategy of the campaign is discussed, including water supply, health education, case management, and vector control. Current issues including the integration of the campaign into primary health care and the mapping of cases by using geographic information systems are also considered. Finally, some lessons for other disease control and eradication programs are outlined.