Sampling techniques for adult Afrotropical malaria vectors and their reliability in the estimation of entomological inoculation rate

Various entomological indicators and sampling techniques are used to monitor and evaluate the impact of many vector control interventions. A number of methods have been used in sampling mosquitoes for the purpose of estimating the entomological inoculation rate (EIR) and each is subject to some bias or shortcomings. It was the aim of this paper to critically evaluate the most common mosquito sampling techniques in relation to their reliability in the estimation of EIR. The techniques include man-landing, light trap, light trap/bednet combination and odour-baited traps. Although man-landing technique is the most reliable, it however, expose the catcher to mosquito-borne infections. On the other hand, light traps have been found to capture mosquitoes with higher sporozoite rates as compared to those from human bait catch thus leading to an overestimation of EIR. From an epidemiological point of view, the use of light-trapbed net combination is an approach that is more meaningful than using light trap alone because, a light trap functions more efficiently when placed near the normal flight paths of mosquitoes such as inside huts or under the eaves. Unfortunately, it has been shown that estimates of EIR are influenced by trap position, hence affecting the number caught and the sporozoite rates. A variety of bednets have been used to sample mosquitoes attracted to man. Studies have shown that bednet traps normally catch fewer mosquitoes than do human baits outside them. Although the collections by indoor resting technique give a good estimate of the mean house density in a given area, they may not necessarily give a good estimate of EIR. Thus the development of improved sampling systems based on an improved understanding of hostoriented behaviour is needed. Moreover, there is need to standardise all the sampling techniques in use to enable us make valid comparisons between various studies done by different people and in different areas. In this article, the inherent limitations of conventional mosquito sampling techniques when used in estimating the EIR are discussed. Keywords: malaria vector, sampling, traps, entomological inoculation rate, Africa Tanzania Health Research Bulletin Vol. 7(3) 2005: 117-12

The role of mass media in disease outbreak reporting in the United Republic of Tanzania

Emerging infectious diseases and the growth of information communication technology have produced new demands and possibilities for disease outbreak information and reporting. An analysis of disease outbreak information and reporting by the Tanzanian mass media was carried out to cover a 12-month period between July 2002 and June 2003. Outbreak episodes reported in four local dailies were collected, compiled and analysed. The disease that received the highest coverage was cholera. Cholera outbreaks were frequently reported from the 3 districts in Dar es Salaam Region. Other epidemic-prone diseases received very little coverage. These included meningitis and rabies. With globalisation and high technological information systems, reports of disease outbreaks are more widely disseminated and more easily accessible than ever before. However, the quality of information is no longer controlled and may be provided out of context, often causing unnecessary public anxiety and confusion. It is important that mass media is provided with accurate epidemiological reports if correct information is to reach the public. The role of media in outbreak reporting is herein discussed in relation to the importance of providing timely and accurate epidemiological information. Tanzania Health Research Bulletin Vol.6(2) 2004: 73-7

Indoors man-biting mosquitoes and their implication on malaria transmission in Mpwapwa and Iringa District, Tanzania

No Abstract

Enhancing disease surveillance reporting using public transport in Dodoma District, Central Tanzania

No Abstract. Tanzania Health Research Bulletin Vol. 7(3) 2005: 201-20

Community knowledge and acceptance of larviciding for malaria control in a rural district of east-central Tanzania

The use of microbial larvicides, a form of larval source management, is a less commonly used malaria control intervention that nonetheless has significant potential as a component of an integrated vector management strategy. We evaluated community acceptability of larviciding in a rural district in east-central Tanzania using data from 962 household surveys, 12 focus group discussions, and 24 in-depth interviews. Most survey respondents trusted in the safety (73.1%) and efficacy of larviciding, both with regards to mosquito control (92.3%) and to reduce malaria infection risk (91.9%). Probing these perceptions using a Likert scale provides a more detailed picture. Focus group participants and key informants were also receptive to larviciding, but stressed the importance of sensitization before its implementation. Overall, 73.4% of survey respondents expressed a willingness to make a nominal household contribution to a larviciding program, a proportion which decreased as the proposed contribution increased. The lower-bound mean willingness to pay is estimated at 2,934 Tanzanian Shillings (approximately US$1.76) per three month period. We present a multivariate probit regression analysis examining factors associated with willingness to pay. Overall, our findings point to a receptive environment in a rural setting in Tanzania for the use of microbial larvicides in malaria control. © 2014 by the authors; licensee MDPI, Basel, Switzerland

Regional Initiatives in Support of Surveillance in East Africa: The East Africa Integrated Disease Surveillance Network (EAIDSNet) Experience.

The East African Integrated Disease Surveillance Network (EAIDSNet) was formed in response to a growing frequency of cross-border malaria outbreaks in the 1990s and a growing recognition that fragmented disease interventions, coupled with weak laboratory capacity, were making it difficult to respond in a timely manner to the outbreaks of malaria and other infectious diseases. The East Africa Community (EAC) partner states, with financial support from the Rockefeller Foundation, established EAIDSNet in 2000 to develop and strengthen the communication channels necessary for integrated cross-border disease surveillance and control efforts. The objective of this paper is to review the regional EAIDSNet initiative and highlight achievements and challenges in its implementation. Major accomplishments of EAIDSNet include influencing the establishment of a Department of Health within the EAC Secretariat to support a regional health agenda; successfully completing a regional field simulation exercise in pandemic influenza preparedness; and piloting a web-based portal for linking animal and human health disease surveillance. The strategic direction of EAIDSNet was shaped, in part, by lessons learned following a visit to the more established Mekong Basin Disease Surveillance (MBDS) regional network. Looking to the future, EAIDSNet is collaborating with the East, Central and Southern Africa Health Community (ECSA-HC), EAC partner states, and the World Health Organization to implement the World Bank-funded East Africa Public Health Laboratory Networking Project (EAPHLNP). The network has also begun lobbying East African countries for funding to support EAIDSNet activities

The relationship between malaria parasitaemia and availability of healthcare facility in Mpwapwa District, central Tanzania

A study was carried out in six villages located at different altitudes in Mpwapwa district of central Tanzania to determine malaria parasitaemia and transmission levels in villages with or without health care facilities. A total of 1119 schoolchildren (age= 5.9-12.3 years) were examined for malaria parasitaemia. Plasmodium falciparum was the predominant malaria species accounting for 92.8% of all species. The average malaria prevalence rate among schoolchildren was 25.8% (range 1.5-53.8%). The geometric mean parasite densities for P. falciparum was 361 (N= 286). Higher malaria prevalence was observed in villages at lower (1500m) altitudes. Schoolchildren in areas with health care facilities were less at risk of acquiring malaria by 33.4% as compared with those living in areas without health facilities. Mean packed cell volume in schoolchildren was 38.5% (range= 35.2-41.0%). Splenomegaly was observed in 18.1% (0-40.2%) of the schoolchildren examined and it was higher among those in villages without health care facilities. Anopheles gambiae sensu lato was the only malaria vector found in the district and was found in all villages and at all altitudes. Sporozoite rate in An. gambiae s.l. ranged from 0-10.5%, with the lowland villages recording the highest rates. This study indicates that altitude and geographical accessibility to healthcare service are important determinants of malaria infection among rural communities in Tanzania. Keywords: malaria, schoolchildren, altitudes, health care facility, Tanzania Tanzania Health Research Bulletin Vol. 8(1) 2006: 22-2

Challenges of implementing an Integrated Disease Surveillance and Response strategy using the current Health Management Information System in Tanzania

Tanzania adopted an Integrated Disease Surveillance and Response (IDSR) strategy in 1998 in order to strengthen its infectious disease surveillance system. During that time, the country had 5 separate surveillance systems to monitor infectious disease trends and disease control programmes. The systems included the Health Management Information System (HMIS); Infectious Disease Week Ending; Tuberculosis/Leprosy; Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome; and Acute Flaccid Paralysis/Poliomyelitis). An assessment of the surveillance systems in the country has shown inadequacy in the use of standard case definitions and laboratory confirmation of cases, supervision and feedback as well as data collection tools. Moreover, in some of the existing vertical disease surveillance programmes, the epidemiological data generated were neither fully analyzed nor utilized at district level, but rather were forwarded to higher levels, which hardly provided any feedback to the lower levels. For these and other reasons, the Ministry of Health adopted the IDSR strategy that will focus on selected priority diseases. Although a significant progress has been made as far as the IDSR strategy is concerned, its implementation is facing several challenges. This is due to the fact that the current surveillance system has to utilize the existing HMIS system in collecting and compiling epidemiological data from health facility and district levels. This paper intends to discuss in detail challenges, which the Ministry of Health and district councils have to take into consideration during the implementation of IDSR strategy. Recommendations are also made for possible adoption to enable smooth running of the IDSR strategy at the national, district and facility levels. Tanzania Health Research Bulletin Vol.6(2) 2004: 57-6

Community knowledge, perceptions and practices on malaria in Mpwapwa District, central Tanzania

A study on community knowledge, attitudes and perception on malaria and its management was conducted in Mpwapwa district of central Tanzania in January-February 2001. Six villages, three with health facilities (Kibakwe, Makose and Mwanawota) and three without health facilities (Chogola, Kidenge and Wangi) lying between 975 and 1859 m above sea level were selected for the study. According to most respondents, the general health problems for adults in the district included malaria, diarrhoea, typhoid fever and pneumonia. Malaria, pneumonia and diarrhoea were the major health problems among children. Among pregnant women, malaria, abortions and diarrhoea were identified as the major public health problems in the district. In the view of most of villagers, malaria was the cause of most fevers and convulsions at low and intermediate altitudes. Cold weather was considered as the main predisposing factor to most of the fevers experienced in the highland villages. The common antimalarial drugs used in Mpwapwa district were chloroquine and quinine. The cost of antimalarial drugs ranged between TShs. 10/- and 20/- for one tablet of chloroquine, 600/- for chloroquine syrup, and 320/- for a single dose of chloroquine injection. However, shortage of drugs was frequently encountered in most of the health facilities. Traditional medicine practitioners were most frequently consulted for cases of convulsions in the district. Our findings showed that only 2.1% of the children in the district were sleeping under mosquito nets. The use of mosquito net was common among individuals living in the villages with health facilities than in those without health facilities. Generally, most respondents considered long distances to health facilities and inability to pay for health services as the main constraints in obtaining proper health care. Tanzania Health Research Bulletin Vol.6(2) 2004: 37-4