Prevalence of Bacterial Febrile Illnesses in Children in Kilosa District, Tanzania.

Bacterial etiologies of non-malaria febrile illnesses have significantly become important due to high mortality and morbidity, particularly in children. Despite their importance, there are few reports on the epidemiology of these diseases in Tanzania, and the true burden of such illnesses remains unknown. This study aimed to identify the prevalence of leptospirosis, brucellosis, typhoid fever and urinary tract infections and their rate of co-infections with malaria. A cross-sectional study was conducted at Kilosa district hospital in Tanzania for 6 months. Febrile children aged from 2-13 years were recruited from the outpatient department. Patients were screened by serological tests such as IgM and IgG ELISA, and microscopic agglutination test. A total of 370 patients were enrolled; of these 85 (23.0%) had malaria parasites, 43 (11.6%) had presumptive acute leptospirosis and 26/200 (13%) had confirmed leptospirosis. Presumptive acute brucellosis due to B. abortus was identified among 26 (7.0%) of patients while B. melitensis was detected in 57 (15.4%) of the enrolled patients. Presumptive typhoid fever due to S. Typhi was identified in thirty eight (10.3%) of the participants and 69 (18.6%) had urinary tract infections. Patients presented with similar symptoms; therefore, the identification of these diseases could not be done based on clinical ground alone. Co-infections between malaria and bacterial febrile illnesses were observed in 146 patients (39.5%). Although antibacterials and/or anti-malarials were prescribed in most patients, some patients did not receive the appropriate treatment. The study has underscored the importance of febrile bacterial diseases including zoonoses such as leptospirosis and brucellosis infebrile children, and thus such illnesses should be considered by clinicians in the differential diagnoses of febrile diseases. However, access to diagnostic tests for discrimination of febrile illnesses is needed. This would allow febrile patients to receive the correct diagnoses and facilitation of accurate and prompt treatment

Leptospira Serovars for Diagnosis of Leptospirosis in Humans and Animals in Africa: Common Leptospira Isolates and Reservoir Hosts

The burden of leptospirosis in humans and animals in Africa is higher than that reported from other parts of the world. However, the disease is not routinely diagnosed in the continent. One of major factors limiting diagnosis is the poor availability of live isolates of locally circulating Leptospira serovars for inclusion in the antigen panel of the gold standard microscopic agglutination test (MAT) for detecting antibodies against leptospirosis. To gain insight in Leptospira serovars and their natural hosts occurring in Tanzania, concomitantly enabling the improvement of the MAT by inclusion of fresh local isolates, a total of 52 Leptospira isolates were obtained from fresh urine and kidney homogenates, collected between 1996 and 2006 from small mammals, cattle and pigs. Isolates were identified by serogrouping, cross agglutination absorption test (CAAT), and molecular typing. Common Leptospira serovars with their respective animal hosts were: Sokoine (cattle and rodents); Kenya (rodents and shrews); Mwogolo (rodents); Lora (rodents); Qunjian (rodent); serogroup Grippotyphosa (cattle); and an unknown serogroup from pigs. Inclusion of local serovars particularly serovar Sokoine in MAT revealed a 10-fold increase in leptospirosis prevalence in Tanzania from 1.9 % to 16.9 % in rodents and 0.26% to 10.75 % in humans. This indicates that local serovars are useful for diagnosis of human and animal leptospirosis in Tanzania and neighbouring countries

Effect of synthetic hormones on reproduction in Mastomys natalensis

Rodent pest management traditionally relies on some form of lethal control. Developing effective fertility control for pest rodent species could be a major breakthrough particularly in the context of managing rodent population outbreaks. This laboratory-based study is the first to report on the effects of using fertility compounds on an outbreaking rodent pest species found throughout sub-Saharan Africa. Mastomys natalensis were fed bait containing the synthetic steroid hormones quinestrol and levonorgestrel, both singly and in combination, at three concentrations (10, 50, 100 ppm) for seven days. Consumption of the bait and animal body mass was mostly the same between treatments when analysed by sex, day and treatment. However, a repeated measures ANOVA indicated that quinestrol and quinestrol+levonorgestrel treatments reduced consumption by up to 45%, particularly at the higher concentrations of 50 and 100 ppm. Although there was no clear concentration effect on animal body mass, quinestrol and quinestrol+levonorgestrel lowered body mass by up to 20% compared to the untreated and levonorgestrel treatments. Quinestrol and quinestrol+levonorgestrel reduced the weight of male rat testes, epididymis and seminal vesicles by 60-80%, and sperm concentration and motility were reduced by more than 95%. No weight changes were observed to uterine and ovarian tissue; however, high uterine oedema was observed among all female rats consuming treated bait at 8 days and 40 days from trial start. Trials with mate pairing showed there were significant differences in the pregnancy rate with all treatments when compared to the untreated control group of rodents

Laboratory evaluation of effects of quinestrol and levonorgestrel on fertility and reproductive performance of multimammate rats Mastomys Natalensis

A DISSERTATION SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN PUBLIC HEALTH AND FOOD SAFETY OF SOKOINE UNIVERSITY OF AGRICULTURE. MOROGORO, TANZANIA.This study was carried out to evaluate the effects of fertility control agents (quinestrol and levonorgestrel) on reproduction performance of multimammate rats (Mastomysnatalensis). A total of 316 individual Mastomysnatalensiswere used to evaluate consumption rate of bait and their effects on reproductive performance under laboratory conditions. Animals were fed with contraceptive baits for seven days, paired and sacrificed for histological observations. Results indicated that acceptance of the control bait was not statistically different (p< 0.001) from that of levonorgestrel at 10 ppm. Acceptance of bait treated with quinestrol at three concentrations (10 ppm, 50 ppm and 100 ppm) was significantly lower (p< 0.001) than plain bait and that of levonorgestrel treatments. Significant interaction effects of treatment and sex were observed (F (16,392) =10.007, p<0.001), with higher acceptance of treated bait for both levonorgestrel and quinestrol in female rats than male rats. Quinestrol, levonorgestrel and quinestrol/levonorgestrel combination significantly reduced testes, epididymis and seminal vesicles weight. Sperm concentration and motility were significantly decreased with increased abnormal sperms morphology. In female animals there were significant differences (F (2, 86) =3.28, p = 0.0423) in pregnancy rate compared to the control group. There were no observed differences in uteri and ovaries weights. All treatment concentrations of quinestrol, levonorgestrel and quinestrol/levonorgestrel combinations had significant effects on pregnancy compared to the control (p< 0.05). The most effective compound was quinestrol which reduced spermatogenesis at all concentrations. Levonorgestrel alone was less effective on male and female reproduction status. These results indicate that quinestrol and/or quinestrol/levonorgestrel combination have anti-fertility effects on M. natalensis

Laboratory evaluation of effects of quinestrol and levonorgestrel on fertility and reproductive performance of multimammate rats Mastomys Natalensis

A DISSERTATION SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN PUBLIC HEALTH AND FOOD SAFETY OF SOKOINE UNIVERSITY OF AGRICULTURE. MOROGORO, TANZANIA.This study was carried out to evaluate the effects of fertility control agents (quinestrol and levonorgestrel) on reproduction performance of multimammate rats (Mastomysnatalensis). A total of 316 individual Mastomysnatalensiswere used to evaluate consumption rate of bait and their effects on reproductive performance under laboratory conditions. Animals were fed with contraceptive baits for seven days, paired and sacrificed for histological observations. Results indicated that acceptance of the control bait was not statistically different (p< 0.001) from that of levonorgestrel at 10 ppm. Acceptance of bait treated with quinestrol at three concentrations (10 ppm, 50 ppm and 100 ppm) was significantly lower (p< 0.001) than plain bait and that of levonorgestrel treatments. Significant interaction effects of treatment and sex were observed (F (16,392) =10.007, p<0.001), with higher acceptance of treated bait for both levonorgestrel and quinestrol in female rats than male rats. Quinestrol, levonorgestrel and quinestrol/levonorgestrel combination significantly reduced testes, epididymis and seminal vesicles weight. Sperm concentration and motility were significantly decreased with increased abnormal sperms morphology. In female animals there were significant differences (F (2, 86) =3.28, p = 0.0423) in pregnancy rate compared to the control group. There were no observed differences in uteri and ovaries weights. All treatment concentrations of quinestrol, levonorgestrel and quinestrol/levonorgestrel combinations had significant effects on pregnancy compared to the control (p< 0.05). The most effective compound was quinestrol which reduced spermatogenesis at all concentrations. Levonorgestrel alone was less effective on male and female reproduction status. These results indicate that quinestrol and/or quinestrol/levonorgestrel combination have anti-fertility effects on M. natalensis

Leptospira infections in freshwater fish in Morogoro Tanzania: a hidden public health threat

Tanzania journal of health research 2014; 16 (2):Leptospirosis caused by spirochete bacterium of genus Leptospira affects humans and animals worldwide. Rodents are major reservoirs of leptospires whereas wetland and aquatic migratory birds also carry and transmit leptospires. Leptospirosis studies in fish are lacking in African countries despite favourable environment and abundant reservoirs, which can spread leptospires into aquatic habitats and infect fish. The objectives of this study were to determine presence of Leptospira in fish; the prevalent Leptospira serovars and whether are related to serovars reported in animals; and to ascertain potential public health risk. Live tilapia, catfish and eel fish (n=48) were caught in Mindu Dam in Morogoro Municipality in eastern Tanzania. Blood sample was collected using syringes and needles to obtain serum for serological detection of leptospirosis using gold standard microagglutination test utilizing local and reference Leptospira serovars Sokoine, Kenya, Pomona and Hebdomadis. Twenty-six fish (54.2%) were positive for serovar Kenya (29.2%) and Sokoine (25%). Leptospira prevalence was high in both catfish (58.3%) and tilapia fish (47.8%). Thus, different fish types are infected with Leptospira found in animals. Fish could be source of Leptospira infection to humans since tilapia and catfish are the common fish type widely consumed in Tanzania. Further study covering lakes, rivers and dams is required to better understand the prevalence of Leptospira in fish and actual public health threats

Predominant leptospiral serogroups circulating among humans, livestock and wildlife in Katavi-Rukwa ecosystem, Tanzania.

BACKGROUND:Leptospirosis is a worldwide zoonotic disease and a serious, under-reported public health problem, particularly in rural areas of Tanzania. In the Katavi-Rukwa ecosystem, humans, livestock and wildlife live in close proximity, which exposes them to the risk of a number of zoonotic infectious diseases, including leptospirosis. METHODOLOGY/PRINCIPAL FINDINGS:A cross-sectional epidemiological study was carried out in the Katavi region, South-west Tanzania, to determine the seroprevalence of Leptospira spp in humans, domestic ruminants and wildlife. Blood samples were collected from humans (n = 267), cattle (n = 1,103), goats (n = 248), buffaloes (n = 38), zebra (n = 2), lions (n = 2), rodents (n = 207) and shrews (n = 11). Decanted sera were tested using the Microscopic Agglutination Test (MAT) for antibodies against six live serogroups belonging to the Leptospira spp, with a cutoff point of ≥ 1:160. The prevalence of leptospiral antibodies was 29.96% in humans, 30.37% in cattle, 8.47% in goats, 28.95% in buffaloes, 20.29% in rodents and 9.09% in shrews. Additionally, one of the two samples in lions was seropositive. A significant difference in the prevalence P<0.05 was observed between cattle and goats. No significant difference in prevalence was observed with respect to age and sex in humans or any of the sampled animal species. The most prevalent serogroups with antibodies of Leptospira spp were Sejroe, Hebdomadis, Grippotyphosa, Icterohaemorrhagie and Australis, which were detected in humans, cattle, goats and buffaloes; Sejroe and Grippotyphosa, which were detected in a lion; Australis, Icterohaemorrhagie and Grippotyphosa, which were detected in rodents; and Australis, which was detected in shrews. Antibodies to serogroup Ballum were detected only in humans. CONCLUSIONS:The results of this study demonstrate that leptospiral antibodies are widely prevalent in humans, livestock and wildlife from the Katavi-Rukwa ecosystem. The disease poses a serious economic and public health threat in the study area. This epidemiological study provides information on circulating serogroups, which will be essential in designing intervention measures to reduce the risk of disease transmission

Seroprevalence of Leptospira infection in bats roosting in human settlements in Morogoro municipality in Tanzania

Leptospirosis is a neglected emerging infectious disease with high burden in Africa. Major reservoirs of leptospirosis are rodents and other small mammals. Studies of leptospirosis in bats and the extent to which they contribute to its transmission to humans and domestic animals in Tanzania are lacking. The objective of this study was to determine the prevalence of leptospirosis and local Leptospira serovars in bat colonies found around human settlements in Morogoro, Tanzania. In this study, mist nets were used to capture bats at Sokoine University of Agriculture main campus, whereas bats roosting on trees at Nunge A, Nunge B and Mwere primary school were captured manually. Leptospirosis was determined using the gold standard microscopic agglutination test for determination of Leptospira antibodies. Six live Leptospira serovars including local Leptospira serovar Sokoine, Kenya and Lora reported in rodents and domestic animals in Tanzania, and reference serovars Hebdomadis, Canicola and Pomona were used in the study. Leptospirosis prevalence was high in bats (19.4%) and higher within colonies (27.3%). Leptospira serovar Sokoine was more prevalent (19.4%) compared to serovars Kenya (2.8%) and Lora (2.8%). Serovars Pomona, Canicola and Hebdomadis were not detected in bats. In conclusion, bats are potential reservoir and transmitter of Leptospira serovar Sokoine, hence should be prevented to access houses and roosting in human settlements to avoid public health risks. Routine diagnosis of human leptospirosis is needed in Tanzania as evidence show a high prevalence of Leptospira in reservoir hosts interacting with humans

The Prevalence of <i>Leptospira</i> Serovars in African Giant Pouched Rats (<i>Cricetomys</i> spp.) from the Ngorongoro Conservation Area, Tanzania

Leptospirosis, also known as Weil’s disease, is a febrile tropical disease of humans and diverse animals. The maintenance hosts of the infectious pathogen, Leptospira spp., are primarily rodents, while other warm-blooded animals and some reptiles are secondary or transient hosts of this pathogen. African giant pouched rats (Cricetomys spp.) have been identified to be important maintenance hosts of pathogenic leptospires in the tropical and subtropical regions of the world. This study assessed the seroprevalence of Leptospira spp. in the African giant pouched rats of the Ngorongoro Conservation Area (NCA), Tanzania, where there is close human, domestic animal, and wildlife interaction. A total of 50 African giant pouched rats were sampled between July 2020 and December 2021. Blood sera were screened for specific leptospiral antibodies using a microscopic agglutination test (MAT), while urine and kidney tissues were examined for the pathogen and pathogen-specific genes using cultures and polymerase chain reactions (PCR), respectively. The pathogen detection varied from 0% in cultures to 6% via the MAT and 20% via PCR. The Fisher exact test was applied to compare positive cases detected through the diagnostic tests, and showed a significant difference in the indirect and direct detection of Leptospira serovars via the MAT and PCR. We conclude that pathogenic Leptospira serovar are found in the NCA and recommend that the NCA authority raises awareness of the existence of the Leptospira serovar in giant African pouched rats, and possibly other rodents. The NCA should initiate appropriate management strategies, including the guided disposal of household garbage, which is the major attractant of rodents to residential areas. Where necessary, the NCA should carry out limited rodent control and periodic monitoring of the pathogen carrier (rodent) populations

Leptospirosis in sugarcane plantation and fishing communities in Kagera northwestern Tanzania.

BackgroundLeptospirosis is a bacterial zoonotic disease of worldwide importance, though relatively neglected in many African countries including sub Saharan Africa that is among areas with high burden of this disease. The disease is often mistaken for other febrile illnesses such as dengue, malaria, rickettsioses and enteric fever. Leptospirosis is an occupational disease likely to affect people working in environments prone to infestation with rodents which are the primary reservoir hosts of this disease. Some of the populations at risk include: sugarcane plantation workers, wetland farmers, fishermen and abattoir workers. In this study we investigated the prevalence of antibodies against Leptospira among sugarcane plantation and factory workers, fishing communities as well as among rodents and shrews in domestic and peridomestic environments within the study areas.MethodsThe study was conducted in Kagera region, northwestern Tanzania and it involved sugarcane plantation workers (cutters and weeders), sugar factory workers and the fishing community at Kagera Sugar Company in Missenyi district and Musira island in Lake Victoria, Kagera, respectively. Blood was collected from consenting human adults, and from rodents and shrews (insectivores) captured live using Sherman traps. Serological detection of leptospiral antibodies in blood serum was carried out by the microscopic agglutination test (MAT).ResultsA total of 455 participants were recruited from the sugarcane plantation (n = 401) and fishing community (n = 54) while 31 rodents and shrews were captured. The overall prevalence of antibodies against Leptospira in human was 15.8%. Sugarcane cutters had higher seroprevalence than other sugar factory workers. Prevalent antibodies against Leptospira serovars in humans were against serovars Lora (6.8%), Sokoine (5.3%), Pomona (2.4%), Hebdomadis (1.1%) and Kenya (0.2%). Detected leptospiral serovars in reservoir hosts were Sokoine (12.5%) and Grippotyphosa (4.2%). Serovar Sokoine was detected both in humans and small mammals.ConclusionLeptospirosis is a public health threat affecting populations at risk, such as sugarcane plantation workers and fishing communities. Public awareness targeting risk occupational groups is much needed for mitigation of leptospirosis in the study areas and other vulnerable populations in Tanzania and elsewhere